WorldWideScience

Sample records for smelt osmerus mordax

  1. Age, growth and sex composition of the American smelt Osmerus mordax(Mitchill), of western Lake Superior

    Science.gov (United States)

    Bailey, Merryll M.

    1964-01-01

    This study is based on 4,561 smelt collected in Chequamegon Bay, the Apostle Islands, the Brule River, and Superior Harbor, all in western Lake Superior. Commercial production in the Great Lakes (U.S. and Canada combined) reached a peak of nearly 16 million pounds in 1960. Production in Lake Superior has generally been small but increased during the 1950's to reach 948,000 pounds in 1960. All O-group and spring I-group smelt had scales with sufficient sculpturing to permit detection of the first annulus. Annulus formation began after 6 June in 1960. In 1961, all smelt had completed the annulus by 24 August. The body-scale relation is a straight line with an intercept of -0.9 inch on the axis of fish length. The weight of western Lake Superior smelt increased as the 2.952 power of the length. A large range of length in each age group and resulting overlap of age-groups II-VI made length a poor index of age. Female smelt grew faster than males after the second year and dominated strongly in age-groups IV-VII. Both sexes made their best annual growth in length (3.3 inches) during their second year of life; the largest weight increments (0.74 ounce, males; 0.85 ounce, females) came in the third year. Best production from a commercial pound net in 1961 occurred when the sex ratios of spawning smelt were nearest 50:50. Spawning male smelt were consistently shorter than females and the average lengths of both sexes decreased as the spawning season progressed. Shortest mature smelt of each sex were 5.0 to 5.2 inches but the males are probably the first to reach 100 percent maturity. All year-old smelt were immature. Among 2-year-old fish, 40.7 per cent of the males and 17.7 percent of the females had reached maturity. All smelt more than 2 years old were mature. Ovaries of 10 smelt contained an average of 31,338 eggs for fish 7.3 to 8.8 inches long.

  2. Using 137Cs as a tool for the assessment and the management of erosion/sedimentation risks in view of the restoration of the Rainbow Smelt (Osmerus mordax) fish population in the Boyer River basin (Quebec, Canada)

    International Nuclear Information System (INIS)

    Bernard, C.; Laverdiere, M.R.

    2000-01-01

    The Boyer River (Quebec, Canada) drains a 217 km 2 watershed that is under cultivation at 60%. The last 2 km of the river bed has always been used as a spawning ground by Rainbow Smelts (Osmerus mordax). This fish population, which plays an important ecological role in the St. Lawrence River estuary, has dramatically declined over the last decades. Siltation and excessive algal growth in the spawning area were identified as the most probable causes of the fish population decline; suggesting that soil erosion, nutrient and sediment transport are major factors underlying the environmental problem. In this context, 137 Cs provides an effective tool for investigating the magnitude and spatial distribution of long-term soil redistribution taking place in the watershed. Sampling of cultivated fields, riverbanks, bottom sediments and forested sites were thus undertaken to help understand the erosive behaviour of the watershed. Results obtained so far suggest in-field erosion rates of up to 13 t ha -1 yr -1 with net outputs reaching 11 t ha -1 yr -1 . These results agree well with estimates obtained from the USLE. The 137 Cs data indicate that fields located in the upstream half of the basin produce smaller sediment loadings than those in the downstream portion, despite higher soil erodibilities and more frequent use for annual crops. They also suggest that more than 75% of the sediment deposited in the spawning area originates from cultivated fields, and less than 25% from streambanks. (author)

  3. Larval nematodes in stomach wall granulomas of smelt Osmerus eperlanus from the German North Sea coast

    OpenAIRE

    Obiekezie, A. I.; Lick, Roland R.; Kerstan, Susanne L.; Möller, Heino

    1992-01-01

    Occurrence of stomach wall granulomas in European smelt was studled at 6 locations along the German North Sea coast. Identification of larval nematodes inhabiting these granulomas is provided for the first time. Three species, isolated by pepsin-HC1 digestion, are involved: Hysterothylacium cf. cornutum, Cosmocephalus obvelatus and Paracuaria tridentata. 72% of all stomachs examined were affected. The ratio of number of granulomas to number of the 3 larval species free in the mesentery was 1:...

  4. Karyotype and chromosomal characteristics of Ag-NOR sites and 5S rDNA in European smelt, Osmerus eperlanus

    Czech Academy of Sciences Publication Activity Database

    Ocalewicz, K.; Hliwa, P.; Krol, J.; Rábová, Marie; Stabinski, R.; Ráb, Petr

    2007-01-01

    Roč. 131, - (2007), s. 29-35 ISSN 0016-6707 R&D Projects: GA AV ČR IAA6045405; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : chromosome banding * cytotaxonomy of smelt * fish cytogenetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.396, year: 2007

  5. Reassessment of the predatory effects of rainbow smelt on ciscoes in Lake Superior

    Science.gov (United States)

    Myers, Jared T.; Jones, Michael L.; Stockwell, Jason D.; Yule, Daniel L.

    2009-01-01

    Evidence from small lakes suggests that predation on larval ciscoes Coregonus artedi by nonnative rainbow smelt Osmerus mordax can lead to cisco suppression or extirpation. However, evidence from larger lakes has led to equivocal conclusions. In this study, we examine the potential predation effects of rainbow smelt in two adjacent but contrasting embayments in Lake Superior (Thunder and Black bays, Ontario). During May 2006, we sampled the ichthyoplankton, pelagic fish communities, and diet composition of rainbow smelt in both bays. Using acoustics and midwater trawling, we estimated rainbow smelt densities to be 476 ± 34/ha (mean ± SE) in Thunder Bay and 3,435 ± 460/ha in Black Bay. We used a bioenergetics model to estimate the proportion of cisco larvae consumed by rainbow smelt. Our results suggest that predation by rainbow smelt accounts for 15–52% and 37–100% of the mortality of larval ciscoes in Thunder and Black bays, respectively, depending on the predator feeding rate and the scale of predator–prey overlap. We also examined the sensitivity of past conclusions (based on 1974 field collections) to assumptions of temporal overlap between rainbow smelt and larval ciscoes and estimates of rainbow smelt abundance derived from bottom trawl samples. After adjusting these parameters to reflect current understanding, we found that the previous predation estimates may have been conservative. We conclude that rainbow smelt may have been a more important contributor to the demise and slow recovery of ciscoes in Lake Superior than previously thought.

  6. Ecological factors affecting Rainbow Smelt recruitment in the main basin of Lake Huron, 1976-2010

    Science.gov (United States)

    O'Brien, Timothy P.; Taylor, William W.; Roseman, Edward F.; Madenjian, Charles P.; Riley, Stephen C.

    2014-01-01

    Rainbow Smelt Osmerus mordax are native to northeastern Atlantic and Pacific–Arctic drainages and have been widely introduced throughout North America. In the Great Lakes region, Rainbow Smelt are known predators and competitors of native fish and a primary prey species in pelagic food webs. Despite their widespread distribution, importance as a prey species, and potential to negatively interact with native fish species, there is limited information concerning stock–recruitment relationships for Rainbow Smelt. To better understand recruitment mechanisms, we evaluated potential ecological factors determining recruitment dynamics for Rainbow Smelt in Lake Huron using data from bottom trawl catches. We specifically evaluated influence of stock size, environmental factors (water temperature, lake levels, and precipitation), and salmonine predation on the production of age-0 recruits from 1976 to 2010. Rainbow Smelt recruitment was negatively related to stock size exceeding 10 kg/ha, indicating that compensatory, density-dependent mortality from cannibalism or intraspecific competition was an important factor related to the production of age-0 recruits. Recruitment was positively related to spring precipitation suggesting that the amount of stream-spawning habitat as determined by precipitation was important for the production of strong Rainbow Smelt recruitment. Additionally, density of age-0 Rainbow Smelt was positively related to Lake Trout Salvelinus namaycush abundance. However, spawning stock biomass of Rainbow Smelt, which declined substantially from 1989 to 2010, was negatively associated with Lake Trout catch per effort suggesting predation was an important factor related to the decline of age-2 and older Rainbow Smelt in Lake Huron. As such, we found that recruitment of Rainbow Smelt in Lake Huron was regulated by competition with or cannibalism by older conspecifics, spring precipitation influencing stream spawning habitats, and predation by Lake Trout on

  7. Status of rainbow smelt in the U.S. waters of Lake Ontario, 2013

    Science.gov (United States)

    Weidel, Brian C.; Connerton, Michael J.

    2014-01-01

    Rainbow Smelt Osmerus mordax are the second most abundant pelagic prey fish in Lake Ontario after Alewife Alosa psuedoharengus. The 2013, USGS/NYSDEC bottom trawl assessment indicated the abundance of Lake Ontario age-1 and older Rainbow Smelt decreased by 69% relative to 2012. Length frequency-based age analysis indicated that age-1 Rainbow Smelt constituted approximately 50% of the population, which is similar to recent trends where the proportion of age-1 has ranged from 95% to 42% of the population. While they constituted approximately half of the catch, the overall abundance index for age 1 was one of the lowest observed in the time series, potentially a result of cannibalism from the previous year class. Combined data from all bottom trawl assessments along the southern shore and eastern basin indicate the proportion of the fish community that is Rainbow Smelt has declined over the past 30 years. In 2013 the proportion of the pelagic fish catch (only pelagic species) that was Rainbow Smelt was the second lowest in the time series at 3.1%. Community diversity indices, based on bottom trawl catches, indicate that Lake Ontario fish community diversity, as assessed by bottom trawls, has sharply declined over the past 36 years and in 2013 the index was the lowest value in the time series. Much of this community diversity decline is driven by changes in the pelagic fish community and dominance of Alewife.

  8. Interactions between hatch dates, growth rates, and mortality of Age-0 native Rainbow Smelt and nonnative Alewife in Lake Champlain

    Science.gov (United States)

    Parrish, Donna; Simonin, Paul W.; Rudstam, Lars G.; Pientka, Bernard; Sullivan, Patrick J.

    2016-01-01

    Timing of hatch in fish populations can be critical for first-year survival and, therefore, year-class strength and subsequent species interactions. We compared hatch timing, growth rates, and subsequent mortality of age-0 Rainbow Smelt Osmerus mordax and Alewife Alosa pseudoharengus, two common open-water fish species of northern North America. In our study site, Lake Champlain, Rainbow Smelt hatched (beginning May 26) almost a month earlier than Alewives (June 20). Abundance in the sampling area was highest in July for age-0 Rainbow Smelt and August for age-0 Alewives. Late-hatching individuals of both species grew faster than those hatching earlier (0.6 mm/d versus 0.4 for Rainbow Smelt; 0.7 mm/d versus 0.6 for Alewives). Mean mortality rate during the first 45 d of life was 3.4%/d for age-0 Rainbow Smelt and was 5.5%/d for age-0 Alewives. Alewife mortality rates did not differ with hatch timing but daily mortality rates of Rainbow Smelt were highest for early-hatching fish. Cannibalism is probably the primary mortality source for age-0 Rainbow Smelt in this lake. Therefore, hatching earlier may not be advantageous because the overlap of adult and age-0 Rainbow Smelt is highest earlier in the season. However, Alewives, first documented in Lake Champlain in 2003, may increase the mortality of age-0 Rainbow Smelt in the summer, which should favor selection for earlier hatching.

  9. Non-stationary recruitment dynamics of rainbow smelt: the influence of environmental variables and variation in size structure and length-at-maturation

    Science.gov (United States)

    Feiner, Zachary S.; Bunnell, David B.; Hook, Tomas O.; Madenjian, Charles P.; Warner, David M.; Collingsworth, Paris D.

    2015-01-01

    Fish stock-recruitment dynamics may be difficult to elucidate because of nonstationary relationships resulting from shifting environmental conditions and fluctuations in important vital rates such as individual growth or maturation. The Great Lakes have experienced environmental stressors that may have changed population demographics and stock-recruitment relationships while causing the declines of several prey fish species, including rainbow smelt (Osmerus mordax). We investigated changes in the size and maturation of rainbow smelt in Lake Michigan and Lake Huron and recruitment dynamics of the Lake Michigan stock over the past four decades. Mean lengths and length-at-maturation of rainbow smelt generally declined over time in both lakes. To evaluate recruitment, we used both a Ricker model and a Kalman filter-random walk (KF-RW) model which incorporated nonstationarity in stock productivity by allowing the productivity term to vary over time. The KF-RW model explained nearly four times more variation in recruitment than the Ricker model, indicating the productivity of the Lake Michigan stock has increased. By accounting for this nonstationarity, we were able identify significant variations in stock productivity, evaluate its importance to rainbow smelt recruitment, and speculate on potential environmental causes for the shift. Our results suggest that investigating mechanisms driving nonstationary shifts in stock-recruit relationships can provide valuable insights into temporal variation in fish population dynamics.

  10. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  11. Host records and tissue locations for Diplostomum mordax (metacercariae) inhabiting the cranial cavity of fishes from Lake Titicaca, Peru.

    Science.gov (United States)

    Heckmann, R A

    1992-06-01

    Metacercariae of Diplostomum mordax were found in the cranial cavity of Orestias agasii, Orestias olivaceous, Orestias luteus, and Basilichthys bonariensis, fishes from Lake Titicaca, Peru. Metacercariae were not found in Oncorhynchus mykiss introduced into the lake during 1939 and 1940. Compression of neural tissue within and on the surface of the brain was observed in all infected fishes. Metacercariae migrating into the cerebrum and cerebellum of the piscine host caused hemorrhaging, cell necrosis, inflammation, fiber formation, and nerve fiber disruption. The presence of D. mordax in B. bonariensis and the 3 species of Orestias constitute new host records. Infections in the cerebrum and cerebellum add new information on specific parasite location.

  12. Kinematics of ram filter feeding and beat-glide swimming in the northern anchovy Engraulis mordax.

    Science.gov (United States)

    Carey, Nicholas; Goldbogen, Jeremy A

    2017-08-01

    In the dense aquatic environment, the most adept swimmers are streamlined to reduce drag and increase the efficiency of locomotion. However, because they open their mouth to wide gape angles to deploy their filtering apparatus, ram filter feeders apparently switch between diametrically opposite swimming modes: highly efficient, streamlined 'beat-glide' swimming, and ram filter feeding, which has been hypothesized to be a high-cost feeding mode because of presumed increased drag. Ram filter-feeding forage fish are thought to play an important role in the flux of nutrients and energy in upwelling ecosystems; however, the biomechanics and energetics of this feeding mechanism remain poorly understood. We quantified the kinematics of an iconic forage fish, the northern anchovy, Engraulis mordax , during ram filter feeding and non-feeding, mouth-closed beat-glide swimming. Although many kinematic parameters between the two swimming modes were similar, we found that swimming speeds and tailbeat frequencies were significantly lower during ram feeding. Rather than maintain speed with the school, a speed which closely matches theoretical optimum filter-feeding speeds was consistently observed. Beat-glide swimming was characterized by high variability in all kinematic parameters, but variance in kinematic parameters was much lower during ram filter feeding. Under this mode, body kinematics are substantially modified, and E. mordax swims more slowly and with decreased lateral movement along the entire body, but most noticeably in the anterior. Our results suggest that hydrodynamic effects that come with deployment of the filtering anatomy may limit behavioral options during foraging and result in slower swimming speeds during ram filtration. © 2017. Published by The Company of Biologists Ltd.

  13. Redescription of Austrodiplostomum compactum (Trematoda: Diplostomidae) from its Type Host and Locality in Venezuela, and of Austrodiplostomum mordax from Argentina.

    Science.gov (United States)

    de Núñez, Margarita Ostrowski

    2017-10-01

    Austrodiplostomum compactum from Nannopterum brasilianus, and its metacercaria from Geophagus sp. and Oreochromis mossambicus captured (1979) at its type locality, Valencia Lake, Venezuela, by the author, are redescribed. The adult is characterized by its large body size, and an oral sucker smaller than the pharynx. The metacercaria has a similar body size as the adult, and the small genital primordia occupy 4.1-7.3% of body length. Experimental infections in chickens with metacercariae of Diplostomulum mordax from brains of Odonthestes bonariensis, captured (2015) at Dique Paso de las Piedras, near Bahia Blanca City, Buenos Aires Province, Argentina, resulted in 10 adults 5 days postexposure. These adults correspond to Austrodiplostomum mordax as described from N. brasilianus at Lacombe Lagoon, Buenos Aires Province, and differ from A. compactum in their smaller body size, and an oral sucker larger than the pharynx. The metacercaria has a similar body size as the adult and differs mainly in that the larger genital primordia occupy 11.6-13.8% of body length. The status of earlier published Austrodiplostomum species in the American continent is discussed in view of available morphological and molecular data. A lectotype of A. mordax is here designated, and Austrodiplostomum ostrowskiae is considered as a new synonym of A. compactum.

  14. Low thermodynamic but high kinetic stability of an antifreeze protein from Rhagium mordax

    DEFF Research Database (Denmark)

    Friis, Dennis Steven; Johnsen, Johannes Lørup; Kristiansen, Erlend

    2014-01-01

    The equilibrium heat stability and the kinetic heat tolerance of a recombinant antifreeze protein (AFP) from the beetle Rhagium mordax (RmAFP1) are studied through differential scanning calorimetry and circular dichroism spectroscopy. In contrast to other insect AFPs studied with this respect......, the RmAFP1 has only one disulfide bridge. The melting temperature, Tm, of the protein is determined to be 28.5°C (pH 7.4), which is much lower than most of those reported for AFPs or globular proteins in general. Despite its low melting temperature, both biophysical and activity measurements show...

  15. Smelting of Scandium by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Satoshi Fujii

    2017-09-01

    Full Text Available Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity. The piezoelectric response of ScAlN suggests that ScAlN thin films formed on a hard substrate would be suitable surface acoustic wave wideband filters for next-generation wireless communication systems. However, it is often difficult to use ScAlN thin films in MEMS devices—including acoustic ones—because of the extremely high price of metallic Sc, given the difficulty associated with smelting it. Here, we propose a novel process for smelting Sc metal by microwave irradiation. Sc metal was able to be obtained successfully from ScF3 through a microwave-irradiation-based carbon reduction reaction. The reaction temperature for this reduction process was approximately 880°C, which is half of that for the conventional smelting process involving reduction with Ca. Thus, the proposed microwave irradiation process has significant potential for use in the smelting of Sc metal.

  16. Energy consumption in smelting reduction (SR) processes

    International Nuclear Information System (INIS)

    Assis, Paulo Santos; Salierno, Giovanni Felice; Fang, Jue; Mankhand, Tilak R.; Assis, Carlos Frederico Campos de

    2010-01-01

    In contrast, conventional processes use coke and hematite/sinter in the blast furnace, in SR processes, other alternative fuels and iron ore sources, like charcoal and fine iron ores, can be used to produce sponge iron. The use of these alternative sources, by SR processes, can reduce environmental impacts and lower production costs. At first, the concepts of the theoretical gas utilization ratio, the smelting heat of the iron ore and the effective calorific value of coal were introduced. Then, the reason for gas utilization ratio and its performance in the shaft as a reducer in the smelting process are discussed and calculated. The relationship between coal consumption and iron ore reduction in the fluidized bed are also discussed. Finally, the influence of post-combustion on coal consumption in an iron bath furnace are calculated and discussed. (author)

  17. Effect of smelt aluminium on mechanical properties of steels

    International Nuclear Information System (INIS)

    Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

    1987-01-01

    Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

  18. Yunnan Smelting Group Examines an Aluminum Project for Possible Investment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Tian Yong,General Manager of Yunnan Smelt- ing Group,has gone to Zha gai NuoEr in Heilongjiang Province with a study group to conduct a full careful examination on the feasi- bility of the investment in the aluminum pro- ject.Yunnan Smelting Group is a large-scale

  19. Recirculation of Chilean copper smelting dust with high impurities contents to the smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Sano, H.; Fujisawa, T. [Nagoya Univ., Nagoya (Japan). EcoTopia Science Inst.; Montenegro, V. [Nagoya Univ., Nagoya (Japan). Dept. of Materials Science and Engineering

    2007-07-01

    Dust generated during the copper smelting process is generally stabilized using hydrometallurgical methods as it contains high concentrations of arsenic. In this laboratory study, dust was recirculated during the smelting process in order to recover more copper and decrease dust emissions while recovering more copper. The behaviour of impurities and their influence on matte quality was also investigated. Industrial matte, flue dust, slag, and copper concentrates from a Chilean smelter were used as test materials. Dust recirculation tests were conducted in a simulated electric furnace. Off-gases were collected in a reaction tube, and the condensed volatile matter, slag, and matte phases were analyzed for their elemental content by inductively coupled plasma atomic emission spectrometry. The distribution of arsenic (As); antimony (Sb), bismuth (Bi), lead (Pb), and zinc (Zn) were investigated by varying the amounts of dust recirculating to the smelting stage with 21 per cent of the oxygen. Results showed that distributions of all analyzed elements increased with recirculation. It was concluded that copper can be recovered using the dust recirculation technique. However, impurities may limit the efficacy of the dust recirculation process. 6 refs., 3 tabs., 4 figs.

  20. Smelting Associated with the Advanced Spent Fuel Conditioning Process

    International Nuclear Information System (INIS)

    Hur, J-M.; Jeong, M-S.; Lee, W-K.; Cho, S-H.; Seo, C-S.; Park, S-W.

    2004-01-01

    The smelting process associated with the advanced spent fuel conditioning process (ACP) of Korea Atomic Energy Research Institute was studied by using surrogate materials. Considering the vaporization behaviors of input materials, the operation procedure of smelting was set up as (1) removal of residual salts, (2) melting of metal powder, and (3) removal of dross from a metal ingot. The behaviors of porous MgO crucible during smelting were tested and the chemical stability of MgO in the salt-being atmosphere was confirmed

  1. Uranium decontamination of common metals by smelting, a review (handbook)

    International Nuclear Information System (INIS)

    Mautz, E.W.; Briggs, G.G.; Shaw, W.E.; Cavendish, J.H.

    1975-01-01

    The published and unpublished literature relating to the smelting of common metals scrap contaminated with uranium-bearing compounds has been searched and reviewed. In general, standard smelting practice produces ingots having a low uranium content, particularly for ferrous, nickel, and copper metals or alloys. Aluminum recovered from uranium contaminated scrap shows some decontamination by smelting but the uranium content is not as low as for other metals. Due to the heterogeneous nature and origin of scrap metals contaminated with uranium, information is frequently missing as to the extent of the initial contamination and the degree of decontamination obtained. The uranium content of the final cast ingots is generally all that is available. Results are summarized below by the primary composition of the uranium contaminated scrap metal. (U.S.)

  2. 76 FR 9409 - National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting

    Science.gov (United States)

    2011-02-17

    ... National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting; Proposed Rule #0;#0... Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting AGENCY: Environmental Protection... standards for hazardous air pollutants (NESHAP) for Primary Lead Smelting to address the results of the...

  3. The development of coke smelting and the industrial revolution

    OpenAIRE

    Macfarlane, Alan

    2004-01-01

    Abraham Darby and the origins of the industrial revolution in Britain. Alan Macfarlane talks to John about the reasons for the area near Birmingham becoming the epi-centre of the industrial development, and the development of coke furnaces and iron smelting.

  4. 31 CFR 101.5 - Payment of smelting costs.

    Science.gov (United States)

    2010-07-01

    ... FORFEITURE OF COUNTERFEIT GOLD COINS § 101.5 Payment of smelting costs. The petitioner shall be required to pay all reasonable costs incurred in extracting the bullion from the counterfeit coins, as shall be determined by the Assistant Secretary. Payment must be made prior to the return of the gold bullion to the...

  5. Project Update: ZVI Used for Arsenic from Lead Smelting Facility

    Science.gov (United States)

    The U.S. EPA Office of Research and Development’s National Risk Management Research Laboratory (NRMRL) is conducting long-term monitoring of a granular iron permeable reactive barrier (PRB) for remediation of ground water contaminated with arsenic from a former lead smelting faci...

  6. Optimization of suspension smelting technology by computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lilius, K; Jokilaakso, A; Ahokainen, T; Teppo, O; Yongxiang, Yang [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1997-12-31

    An industrial-scale flash smelting furnace and waste-heat boilers have been modelled by using commercial Computational-Fluid-Dynamics software. The work has proceeded from cold gas flow to heat transfer, combustion, and two-phase flow simulations. In the present study, the modelling task has been divided into three sub-models: (1) the concentrate burner, (2) the flash smelting furnace (reaction shaft and uptake shaft), and (3) the waste-heat boiler. For the concentrate burner, the flow of the process gas and distribution air together with the concentrate or a feed mixture was simulated. Eulerian - Eulerian approach was used for the carrier gas-phase and the dispersed particle-phase. A large parametric study was carried out by simulating a laboratory scale burner with varying turbulence intensities and then extending the simulations to the industrial scale model. For the flash smelting furnace, the simulation work concentrated on gas and gas-particle two-phase flows, as well as the development of combustion model for sulphide concentrate particles. Both Eulerian and Lagrangian approaches have been utilised in describing the particle phase and the spreading of the concentrate in the reaction shaft as well as the particle tracks have been obtained. Combustion of sulphides was first approximated with gaseous combustion by using a built-in combustion model of the software. The real oxidation reactions of the concentrate particles were then coded as a user-defined sub-routine and that was tested with industrial flash smelting cases. For the waste-heat boiler, both flow and heat transfer calculations have been carried out for an old boiler and a modified boiler SULA 2 Research Programme; 23 refs.

  7. Nonmetallic inclusions in carbon steel smelted in plasma furnace

    Energy Technology Data Exchange (ETDEWEB)

    Shengelaya, I B; Kostyakov, V N; Nodiy, T K; Imerlishvili, V G; Gavisiani, A G [AN Gruzinskoj SSR, Tbilisi. Inst. Metallurgii

    1979-01-01

    A complex investigation on nonmetallic inclusions in carbon cast iron, smelted in plasma furnace in argon atmosphere and cast partly in the air and partly in argon atmosphere, has been carried out. As compared to open-hearth furnace carbon steel, the test metal was found to contain more oxide inclusions and nitrides; besides, in chromium-containing metal, chromium nitrides form the larger part of nitrides.

  8. Optimization of suspension smelting technology by computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lilius, K.; Jokilaakso, A.; Ahokainen, T.; Teppo, O.; Yang Yongxiang [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1996-12-31

    An industrial-scale flash smelting furnace and waste-heat boilers have been modelled by using commercial Computational-Fluid-Dynamics software. The work has proceeded from cold gas flow to heat transfer, combustion, and two-phase flow simulations. In the present study, the modelling task has been divided into three sub-models: (1) the concentrate burner, (2) the flash smelting furnace (reaction shaft and uptake shaft), and (3) the waste-heat boiler. For the concentrate burner, the flow of the process gas and distribution air together with the concentrate or a feed mixture was simulated. Eulerian - Eulerian approach was used for the carrier gas-phase and the dispersed particle-phase. A large parametric study was carried out by simulating a laboratory scale burner with varying turbulence intensities and then extending the simulations to the industrial scale model. For the flash smelting furnace, the simulation work concentrated on gas and gas-particle two-phase flows, as well as the development of combustion model for sulphide concentrate particles. Both Eulerian and Lagrangian approaches have been utilised in describing the particle phase and the spreading of the concentrate in the reaction shaft as well as the particle tracks have been obtained. Combustion of sulphides was first approximated with gaseous combustion by using a built-in combustion model of the software. The real oxidation reactions of the concentrate particles were then coded as a user-defined sub-routine and that was tested with industrial flash smelting cases. For the waste-heat boiler, both flow and heat transfer calculations have been carried out for an old boiler and a modified boiler SULA 2 Research Programme; 23 refs.

  9. Design requirements for a metal-smelting facility

    International Nuclear Information System (INIS)

    Williams, L.C.; Mack, J.E.

    1982-01-01

    Functional requirements for the smelting of metal scrap contaminated with low-enriched uranium in a Metal Smelting Faclity (MSF) have been determined. The process will be designed to smelt ferrous metal scrap that has accumulated at the Oak Ridge Gaseous Diffusion Plant (ORGDP) into one-ton ingots at a rate of 40 ingots per day (10,000 tons/year). Total scrap inventories at the ORGDP are currently estimated at 28,000 tons. The diffusion plant scrap is primarily contaminated with 100 to 200 ppm U at an enrichment of 0.5 to 1.5% 235 U. The scrap is considered special nuclear material (SNM) and cannot be handled by commercial smelters without specific licensing. Slagging will be performed to remove contaminants from the metal and concentrate them in the slag. Process systems will include scrap handling, size reduction, preheating and charging, melting and slagging, ingot casting and storage, and fume exhaust. The MSF has been proposed for FY 1984 line item funding

  10. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    International Nuclear Information System (INIS)

    Török, B; Thiele, A

    2013-01-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well

  11. Directly smelted lead-tin alloys: A historical perspective

    Science.gov (United States)

    Dube, R. K.

    2010-08-01

    This paper discusses evidence related to the genesis and occurrence of mixed lead-tin ore deposit consisting of cassiterite and the secondary minerals formed from galena. These evidences belong to a very long time period ranging from pre-historic to as late as the nineteenth century a.d. This type of mixed ore deposits was smelted to prepare lead-tin alloys. The composition of the alloy depended on the composition of the starting ore mixture. A nineteenth century evidence for the production of directly smelted lead-tin alloys in southern Thailand is discussed. A unique and rather uncommon metallurgical terminology in Sanskrit language— Nāgaja—was introduced in India for the tin recovered from impure lead. This suggests that Indians developed a process for recovering tin from lead-tin alloys, which in all probability was based on the general principle of fire refining. It has been shown that in the context of India the possibility of connection between the word Nāgaja and the directly smelted lead-tin alloys cannot be ruled out.

  12. Designing of Synergistic Waste Mixtures for Multiphase Reactive Smelting

    Directory of Open Access Journals (Sweden)

    Vaso Manojlović

    2016-06-01

    Full Text Available Electric arc furnace (EAF dust, together with a mill scale and coke were smelted in a laboratory electric arc furnace. These metallurgical wastes consist of a many different phases and elements, making the reaction process complex. Thermo-chemical analysis of the reactions in metal, slag, and gas phases was done, and used for modeling of the mixture composition and energy consumption required for smelting. Modelling was performed with the software named RikiAlC. The crude ZnO, slag, and metal phase were analyzed using the atomic absorption spectrometry (AAS, the optical emission spectrometry with inductively coupled plasma (ICP-OES, the X-ray diffraction (XRD, the scanning electron microscopy (SEM equipped with energy dispersive spectrometry (EDS, and reflected and transmitted light microscopy. Also, in order to follow the behavior of this process the exhausted gases were monitored. The synergetic effects of the designed mixture may be recognized in minimizing energy consumption for the smelting process, improving the product yield efficiency, and reducing the negative environmental effects.

  13. Mercury distribution characteristics in primary manganese smelting plants

    International Nuclear Information System (INIS)

    Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

    2017-01-01

    The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1–99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. - Graphical abstract: 1. Lack of data on mercury (Hg) distribution in manganese smelters. 2. Mass distribution of Hg released from 3 plants (as normalized values) were made as follows by measurements. 3. Information of distribution of Hg in Manganese smelters would be used for emission in to air and releases to other streams for the nation and globe in UNEP mercury report. - Highlights: • The mass balance study by on-site measurement from primary manganese smelting plants was made at first time in the world. • Hg distribution and main input and release pathways of Hg from primary manganese smelting plants could be found as the first time. • Gas temperature in bag filter affects Hg behavior and speciation changes in APCDs. • National inventory of Hg emssion has been updated with new data. - Mercury distribution in manganese smelting plant was investigated as the first measurements at commercial plants in the world. National Hg release

  14. Foraging and predation risk for larval cisco (Coregonus artedi) in Lake Superior: a modelling synthesis of empirical survey data

    Science.gov (United States)

    Myers, Jared T.; Yule, Daniel L.; Jones, Michael L.; Quinlan, Henry R.; Berglund, Eric K.

    2014-01-01

    The relative importance of predation and food availability as contributors to larval cisco (Coregonus artedi) mortality in Lake Superior were investigated using a visual foraging model to evaluate potential predation pressure by rainbow smelt (Osmerus mordax) and a bioenergetic model to evaluate potential starvation risk. The models were informed by observations of rainbow smelt, larval cisco, and zooplankton abundance at three Lake Superior locations during the period of spring larval cisco emergence and surface-oriented foraging. Predation risk was highest at Black Bay, ON, where average rainbow smelt densities in the uppermost 10 m of the water column were >1000 ha−1. Turbid conditions at the Twin Ports, WI-MN, affected larval cisco predation risk because rainbow smelt remained suspended in the upper water column during daylight, placing them alongside larval cisco during both day and night hours. Predation risk was low at Cornucopia, WI, owing to low smelt densities (cisco survival at Black Bay and to a lesser extent at Twin Ports, and that starvation may be a major source of mortality at all three locations. The framework we describe has the potential to further our understanding of the relative importance of starvation and predation on larval fish survivorship, provided information on prey resources available to larvae are measured at sufficiently fine spatial scales and the models provide a realistic depiction of the dynamic processes that the larvae experience.

  15. Moessbauer study of ancient iron smelting slag in Japan

    International Nuclear Information System (INIS)

    Nakanishi, A.

    2008-01-01

    For an investigation of the ancient iron manufacturing technique, a reproducing experiment was carried out by archaeologists, where ancient type of iron smelting furnace was built and iron sand with high titanium contents was used as the raw material. During the operation of furnace, a large amount of slag flowed away from the furnace. In order to investigate the possibility for the estimation about the operative condition of furnace and the raw material, 57 Fe Moessbauer spectroscopy was applied for characterizing these slags and it was found that these slags mainly consisted of ferropseudobrookite (FeTi 2 O 5 ).

  16. State of the art of smelting lead-acid battery scrap

    Energy Technology Data Exchange (ETDEWEB)

    Melin, A

    1977-02-01

    A discussion is given of the economic importance of lead recovery and of scrap recycling in the battery industry. Various possibiliies of processing battery scrap, either by direct smelting or by smelting after preparaton are discussed, and the BBU, the Stolberger, and the Tonnolli methods are compared

  17. Copper smelting and sediment pollution in Bronze Age China.

    Science.gov (United States)

    Zhang, S.; Dong, G.

    2017-12-01

    The emergence and diffusion of metallurgical technology had tremendous environmental consequence, however, the spatial-temporal consequences of the metallurgy during Bronze Age are not clear in China. Here, Xray fluorescence (XRF) measurement and principal component analysis (PCA) were conducted on heavy metal element (Cu, Ni, Pb, Zn, Cr and As) concentrations (HMEC) of natural and anthropogenic sediment samples systematically collected from 22 late Neolithic-Bronze Age sites in Hexi corridor to explore the potential for subcontinental-wide changes in soil geochemistry. We place this data within the context of the Cu concentrations in lacustrine sediments located near smelting and mining centers in Bronze Age China. Our results show that variation of HMEC in anthropogenic sediment in Hexi corridor is contemporaneous with the increases of the Cu concentrations in lacustrine sediment around 4000 BP. Comparative data suggests the metallurgical production diffused from the Hexi corridor to central and southwestern China around 3600 BP. We argue that sediment pollution is not an isolated phenomenon during the Bronze Age China, but rather occurred on regional scales and is closely related to the intensity of smelting activities.

  18. Preparation of Inconel 740 superalloy by electron beam smelting

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); You, Qifan; Shi, Shuang; Li, Jiayan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Ye, Fei [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Wei, Xin [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2016-08-15

    A novel method, namely electron beam smelting (EBS) technology was used to prepare the Inconel 740 superalloy. The microstructures, hardness and oxidation behavior were characterized and compared with the traditionally prepared Inconel 740 superalloy. The results imply that the solution treatment gives rise to the coarsening of γ′ precipitates, with further aging treatment, the γ′ precipitates with size of less than 30 nm are distributed dispersively in the matrix, leading to a decreasing of the lattice parameters and an increasing of the misfit. The γ′ precipitates result in shearing mechanism of weakly pair coupling. The EBS 740 superalloy produces better properties than that prepared in the traditional method in both precipitation strengthening effect and oxidation resistance. - Highlights: • Electron beam smelting, a new method, was used to prepare the Inconel 740 superalloy. • The EBS 740 shows higher strengthening effect than 740 made in traditional method. • The EBS 740 shows better oxidation resistance than traditional 740. • It shows application prospect of EBS technology in preparing Ni-base superalloys.

  19. Maturity, size at age and predator-prey relationships of winter skate Leucoraja ocellata in the southern Gulf of St Lawrence: potentially an undescribed endemic facing extirpation.

    Science.gov (United States)

    Kelly, J T; Hanson, J M

    2013-03-01

    The goals of this study were to document the size and age structure, size at maturity, ovarian fecundity and diet of the endangered population of winter skate Leucoraja ocellata that resides in the southern Gulf of St Lawrence (SGSL). The maximum size observed for SGSL L. ocellata was 68 cm total length (LT ) but >99% of animals caught were 10 mm diameter were ever observed. At 40 cm LT , the diet changed from one dominated by shrimp Crangon septemspinosa and gammarid amphipods to one dominated by fishes (mainly sand lance Ammodytes spp. and rainbow smelt Osmerus mordax) and Atlantic rock crab Cancer irroratus. Sufficient differences were observed between SGSL L. ocellata and other populations in their size-at-maturity pattern and maximum size to propose the taxonomic re-evaluation of the population. © Her Majesty the Queen in Right of Canada 2013. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  20. Update COSEWIC status report on the shortjaw cisco, Coregonus zenithicus, in Canada

    Science.gov (United States)

    Todd, Thomas N.

    2003-01-01

    Extirpated in most of the Great Lakes, the shortjaw cisco, Coregonus zenithicus, is currently found in Lakes Superior and Nipigon in addition to at least 22 Canadian lakes. The species exhibits morphological and genetic variability throughout its range and may consist of more than one distinct taxon. However, a common morph is widely distributed from the Great Lakes to the Northwest Territories, consistent with a hypothesis of preglacial origin for the species. Shortjaw ciscoes have declined because of excessive exploitation by food fisheries, habitat degradation, and predation and competition with introduced and exotic species such as alewife, Alosa pseudoharengus, and rainbow smelt, Osmerus mordax. The status of the species in most Canadian lakes is unknown, but continuing declines in those lakes that have been monitored suggest that the shortjaw cisco should be considered as threatened throughout its range.

  1. Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

    2018-04-01

    Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

  2. Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

    2018-06-01

    Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

  3. Adaptive PCA based fault diagnosis scheme in imperial smelting process.

    Science.gov (United States)

    Hu, Zhikun; Chen, Zhiwen; Gui, Weihua; Jiang, Bin

    2014-09-01

    In this paper, an adaptive fault detection scheme based on a recursive principal component analysis (PCA) is proposed to deal with the problem of false alarm due to normal process changes in real process. Our further study is also dedicated to develop a fault isolation approach based on Generalized Likelihood Ratio (GLR) test and Singular Value Decomposition (SVD) which is one of general techniques of PCA, on which the off-set and scaling fault can be easily isolated with explicit off-set fault direction and scaling fault classification. The identification of off-set and scaling fault is also applied. The complete scheme of PCA-based fault diagnosis procedure is proposed. The proposed scheme is first applied to Imperial Smelting Process, and the results show that the proposed strategies can be able to mitigate false alarms and isolate faults efficiently. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Delta smelt: Life history and decline of a once abundant species in the San Francisco Estuary

    Science.gov (United States)

    Moyle, Peter B.; Brown, Larry R.; Durand, John R; Hobbs, James A.

    2016-01-01

    This paper reviews what has been learned about Delta Smelt and its status since the publication of The State of Bay-Delta Science, 2008 (Healey et al. 2008). The Delta Smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of California’s water supply system, Delta Smelt has been the focus of a large research effort to understand causes of decline and identify ways to recover the species. Since 2008, a remarkable record of innovative research on Delta Smelt has been achieved, which is summarized here. Unfortunately, research has not prevented the smelt’s continued decline, which is the result of multiple, interacting factors. A major driver of decline is change to the Delta ecosystem from water exports, resulting in reduced outflows and high levels of entrainment in the large pumps of the South Delta. Invasions of alien species, encouraged by environmental change, have also played a contributing role in the decline. Severe drought effects have pushed Delta Smelt to record low levels in 2014–2015. The rapid decline of the species and failure of recovery efforts demonstrate an inability to manage the Delta for the “co-equal goals” of maintaining a healthy ecosystem and providing a reliable water supply for Californians. Diverse and substantial management actions are needed to preserve Delta Smelt.

  5. Mercury distribution characteristics in primary manganese smelting plants.

    Science.gov (United States)

    Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

    2017-08-01

    The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1-99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. Copyright © 2017. Published by Elsevier Ltd.

  6. An updated conceptual model of Delta Smelt biology: Our evolving understanding of an estuarine fish

    Science.gov (United States)

    Baxter, Randy; Brown, Larry R.; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven D.; Dekar, Matthew P.; Dekar, Melissa; Feyrer, Frederick; Hunt, Thaddeus; Jones, Kristopher; Kirsch, Joseph; Mueller-Solger, Anke; Nobriga, Matthew; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Erickson, Gregg; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce

    2015-01-01

    The main purpose of this report is to provide an up-to-date assessment and conceptual model of factors affecting Delta Smelt (Hypomesus transpacificus) throughout its primarily annual life cycle and to demonstrate how this conceptual model can be used for scientific and management purposes. The Delta Smelt is a small estuarine fish that only occurs in the San Francisco Estuary. Once abundant, it is now rare and has been protected under the federal and California Endangered Species Acts since 1993. The Delta Smelt listing was related to a step decline in the early 1980s; however, population abundance decreased even further with the onset of the “pelagic organism decline” (POD) around 2002. A substantial, albeit short-lived, increase in abundance of all life stages in 2011 showed that the Delta Smelt population can still rebound when conditions are favorable for spawning, growth, and survival. In this report, we update previous conceptual models for Delta Smelt to reflect new data and information since the release of the last synthesis report about the POD by the Interagency Ecological Program for the San Francisco Estuary (IEP) in 2010. Specific objectives include:

  7. Reaction Mechanism and Distribution Behavior of Arsenic in the Bottom Blown Copper Smelting Process

    Directory of Open Access Journals (Sweden)

    Qinmeng Wang

    2017-08-01

    Full Text Available The control of arsenic, a toxic and carcinogenic element, is an important issue for all copper smelters. In this work, the reaction mechanism and distribution behavior of arsenic in the bottom blown copper smelting process (SKS process were investigated and compared to the flash smelting process. There are obvious differences of arsenic distribution in the SKS process and flash process, resulting from the differences of oxygen potentials, volatilizations, smelting temperatures, reaction intensities, and mass transfer processes. Under stable production conditions, the distributions of arsenic among matte, slag, and gas phases are 6%, 12%, and 82%, respectively. Less arsenic is reported in the gas phase with the flash process than with the SKS process. The main arsenic species in gas phase are AsS (g, AsO (g, and As2 (g. Arsenic exists in the slag predominantly as As2O3 (l, and in matte as As (l. High matte grade is harmful to the elimination of arsenic to gas. The changing of Fe/SiO2 has slight effects on the distributions of arsenic. In order to enhance the removal of arsenic from the SKS smelting system to the gas phase, low oxygen concentration, low ratios of oxygen/ore, and low matte grade should be chosen. In the SKS smelting process, no dust is recycled, and almost all dust is collected and further treated to eliminate arsenic and recover valuable metals by other process streams.

  8. Mathematical model of whole-process calculation for bottom-blowing copper smelting

    Science.gov (United States)

    Li, Ming-zhou; Zhou, Jie-min; Tong, Chang-ren; Zhang, Wen-hai; Li, He-song

    2017-11-01

    The distribution law of materials in smelting products is key to cost accounting and contaminant control. Regardless, the distribution law is difficult to determine quickly and accurately by mere sampling and analysis. Mathematical models for material and heat balance in bottom-blowing smelting, converting, anode furnace refining, and electrolytic refining were established based on the principles of material (element) conservation, energy conservation, and control index constraint in copper bottom-blowing smelting. Simulation of the entire process of bottom-blowing copper smelting was established using a self-developed MetCal software platform. A whole-process simulation for an enterprise in China was then conducted. Results indicated that the quantity and composition information of unknown materials, as well as heat balance information, can be quickly calculated using the model. Comparison of production data revealed that the model can basically reflect the distribution law of the materials in bottom-blowing copper smelting. This finding provides theoretical guidance for mastering the performance of the entire process.

  9. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Q.; Gao, J.; Chen, X.; Wei, X.

    2016-10-01

    The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al{sub 2}O{sub 3}/SiO{sub 2}, the addition of CaF{sub 2}, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol{sup -}1. (Author)

  10. Development and Application of SKSSIM Simulation Software for the Oxygen Bottom Blown Copper Smelting Process

    Directory of Open Access Journals (Sweden)

    Qinmeng Wang

    2017-10-01

    Full Text Available The oxygen bottom blown copper smelting process (SKS process is a newly developed intense smelting process, which has been widely applied to copper production in China. A multiphase equilibrium model for the SKS process was established based on its mechanism characteristics and the principle of Gibbs energy minimization, and an efficient simulation software—SKSSIM (SKS Simulation—was developed based on the model. Industrial data from the SKS process were used to compare with the calculated data from the SKSSIM software. The calculated data on the compositions of slag and matte as well as the distribution ratios of minor elements (such as Pb, Zn, As, Sb and Bi among the slags, mattes and off-gases were in good agreement with the actual plant data. Accordingly, the SKSSIM simulation software has the potentail to be used for the prediction of smelting production and for optimizing the operating parameters of the SKS process.

  11. Energy Consumption in Copper Smelting: A New Asian Horse in the Race

    Science.gov (United States)

    Coursol, P.; Mackey, P. J.; Kapusta, J. P. T.; Valencia, N. Cardona

    2015-05-01

    After a marked improvement in energy consumption in copper smelting during the past few decades, technology development has been slowing down in the Americas and in Europe. Innovation, however, is still required to further reduce energy consumption while complying with stringent environmental regulations. The bottom blowing smelting technology being developed in China shows success and promise. The general configuration of the bath smelting vessel, the design of high-pressure injectors, and the concentrate addition system are described and discussed in this article with respect to those used in other technologies. The bottom blowing technology is shown to be operating at a temperature in the range of 1160-1180°C, which is the lowest reported temperature range for a modern copper smelting process. In this article, it is suggested that top feeding of filter cake concentrate, which is also used in other technologies, has a positive effect in reducing the oxidation potential of the slag ( p(O2)) while increasing the FeS solubility in slag. This reduction in p(O2) lowers the magnetite liquidus of the slag, while the increased solubility of FeS in slag helps toward reaching very low copper levels in flotation slag tailings. The application of high-pressure injectors allows for the use of high levels of oxygen enrichment with no requirements for punching. Using a standard modeling approach from the authors' previous studies, this article discusses these aspects and compares the energy consumption of the bottom blowing technology with that of other leading flash and bath smelting technologies, namely: flash smelting, Noranda/Teniente Converter, TSL (Isasmelt [Glencore Technology Pty. Ltd., Brisbane, Queensland, Australia]/Outotec), and the Mitsubishi Process (Mitsubishi Materials Corporation, Tokyo, Japan).

  12. Comparing climate change and species invasions as drivers of coldwater fish population extirpations.

    Directory of Open Access Journals (Sweden)

    Sapna Sharma

    Full Text Available Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax on cisco (Coregonus artedii population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.

  13. A study on the smelting of electrolytically reduced spent fuel by using surrogates

    International Nuclear Information System (INIS)

    Hur, Jin-Mok; Jeong, Myoung-Soo; Cho, Soo-Haeng; Seo, Chung-Seok; Park, Seong-Won

    2005-01-01

    A smelting as a part of the advanced spent fuel conditioning process (ACP) was studied by using surrogate materials. Residual salts including LiCl-Li 2 O were successfully separated from the metal components by an evaporation at 950degC. The melting of the metal was characterized, especially by considering the oxidation of the fine metal particles. The operation procedure of the smelting was set up as 1) removal of residual salts, 2) melting of the metal powder, and 3) a solidification of the melted mass to an ingot. (author)

  14. Turbidity and salinity affect feeding performance and physiological stress in the endangered delta smelt.

    Science.gov (United States)

    Hasenbein, Matthias; Komoroske, Lisa M; Connon, Richard E; Geist, Juergen; Fangue, Nann A

    2013-10-01

    Coastal estuaries are among the most heavily impacted ecosystems worldwide with many keystone fauna critically endangered. The delta smelt (Hypomesus transpacificus) is an endangered pelagic fish species endemic to the Sacramento-San Joaquin Estuary in northern California, and is considered as an indicator species for ecosystem health. This ecosystem is characterized by tidal and seasonal gradients in water parameters (e.g., salinity, temperature, and turbidity), but is also subject to altered water-flow regimes due to water extraction. In this study, we evaluated the effects of turbidity and salinity on feeding performance and the stress response of delta smelt because both of these parameters are influenced by water flows through the San Francisco Bay Delta (SFBD) and are known to be of critical importance to the completion of the delta smelt's life cycle. Juvenile delta smelt were exposed to a matrix of turbidities and salinities ranging from 5 to 250 nephelometric turbidity units (NTUs) and 0.2 to 15 parts per thousand (ppt), respectively, for 2 h. Best statistical models using Akaike's Information Criterion supported that increasing turbidities resulted in reduced feeding rates, especially at 250 NTU. In contrast, best explanatory models for gene transcription of sodium-potassium-ATPase (Na/K-ATPase)-an indicator of osmoregulatory stress, hypothalamic pro-opiomelanocortin-a precursor protein to adrenocorticotropic hormone (expressed in response to biological stress), and whole-body cortisol were affected by salinity alone. Only transcription of glutathione-S-transferase, a phase II detoxification enzyme that protects cells against reactive oxygen species, was affected by both salinity and turbidity. Taken together, these data suggest that turbidity is an important determinant of feeding, whereas salinity is an important abiotic factor influencing the cellular stress response in delta smelt. Our data support habitat association studies that have shown greater

  15. Notes from the Field: Acute Mercury Poisoning After Home Gold and Silver Smelting--Iowa, 2014.

    Science.gov (United States)

    Koirala, Samir; Leinenkugel, Kathy

    2015-12-18

    In March 2014, a man, aged 59 years, who lived alone and had been using different smelting techniques viewed on the Internet to recover gold and silver from computer components, was evaluated at a local emergency department for shortness of breath, tremors, anorexia, and generalized weakness. During the smelting processes, he had used hydrogen peroxide, nitric acid, muriatic acid, and sulfuric acid purchased from local stores or Internet retailers. For protection, he wore a military gas mask of unknown type. The mask was used with filter cartridges, but their effectiveness against chemical fumes was not known.

  16. Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

    Science.gov (United States)

    Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

    2011-01-01

    1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

  17. Migration of diadromous and landlocked smelt populations studies by otolith geochemistry

    NARCIS (Netherlands)

    Phung, A.T.; Tulp, I.Y.M.; Baeyens, W.; Elskens, M.; Leermakers, M.; Gao, Y.

    2015-01-01

    Laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to determine Sr and Ba profiles along the growth axis of otholiths of European smelt caught in the Wadden Sea, the IJsselmeer and the Markermeer and to investigate the migration behaviour of the fish between the freshwater

  18. RISK ASSESSMENT AND REMEDIATION OF SOILS CONTAMINATED BY MINING AND SMELTING OF LEAD, ZINC AND CADMIUM

    Science.gov (United States)

    Mining nd smelting of Pb, Zn and Cd ores have caused widespread soil contamination in many countries. In locations with severe soil contamination, and strongly acidic soil or mine waste, ecosystems are devastated. Research has shown that An phytotoxicity, Pb-induced phosphate def...

  19. Reductive-sulfurizing smelting treatment of smelter slag for copper and cobalt recovery

    Directory of Open Access Journals (Sweden)

    Li Y.

    2018-01-01

    Full Text Available Recovery of copper and cobalt from smelter slag using reductive-sulfurizing smelting method was performed in this study. The effects of reductive agent (coke, sulfurizing agent (pyrite, slag modifier (CaO and smelting temperature and duration on the extractive efficiencies of Cu, Co and Fe were discussed. The phase compositions and microstructure of the materials, copper-cobalt matte and cleaned slag were determined. The results showed that copper and cobalt contents in cleaned slag could decrease averagely to 0.18% and 0.071% respectively after cleaning. 91.99% Cu and 92.94% Co and less than 38.73% Fe were recovered from the smelter slag under the optimum conditions: 6 wt.% coke, 20 wt.% pyrite and 6 wt.% CaO addition to the smelter slag, smelting temperature of 1350°C and smelting duration of 3h. The addition of CaO can increase the selectivity of Co recovery. The cleaning products were characterized by XRD and SEM-EDS analysis. The results showed that the main phases of copper-cobalt matte were iron sulfide (FeS, geerite (Cu8S5, iron cobalt sulfide (Fe0.92Co0.08S and Fe-Cu-Co alloy. The cleaned slag mainly comprised fayalite (Fe2SiO4, hedenbergite (CaFe(Si2O6 and magnetite (Fe3O4.

  20. Effects of a reducer type on copper flash smelting slag decopperisation

    Directory of Open Access Journals (Sweden)

    B. Oleksiak

    2015-01-01

    Full Text Available In the paper, results of investigations on coke dust, anthracite dust and coal flotation concentrate application in the technology of copper flash smelting slag processing are presented. The results show that the selected reducers can be used as substitutes for the conventional coke.

  1. [Limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou].

    Science.gov (United States)

    Lin, Wen-Jie; Xiao, Tang-Fu; Ao, Zi-Qiang; Xing, Jun; Ma, Huan-Cheng; Hu, Ting-Xing

    2007-03-01

    With indigenous zinc smelting waste residue, contaminated soil and background soil as test substrates, a pot experiment was conducted to study the growth characteristics of Lolium perenne and Trifolium pretense on these substrates. The results showed that the major limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou were the salt-alkali stress and the lower contents of organic matter, total N, available N and total K. The heavy metals in waste residue had a high concentration, but their available forms only occupied a small proportion, with low toxicity to plant but having potential harmful risk. Contaminated soil had lower concentrations of heavy metals than waste residue, but its contained heavy metals were more in available form. The constraints of revegetation on contaminated soil were the toxicity of heavy metals and the low contents of available P and K. Mixing contaminated soil with zinc smelting waste residue could be one of the effective approaches for the substrate amendment in indigenous zinc smelting areas.

  2. Distribution and health risk assessment to heavy metals near smelting and mining areas of Hezhang, China.

    Science.gov (United States)

    Briki, Meryem; Zhu, Yi; Gao, Yang; Shao, Mengmeng; Ding, Huaijian; Ji, Hongbing

    2017-08-19

    Mining and smelting areas in Hezhang have generated a large amount of heavy metals into the environment. For that cause, an evaluative study on human exposure to heavy metals including Co, Ni, Cu, Zn, Cr, As, Cd, Pb, Sb, Bi, Be, and Hg in hair and urine was conducted for their concentrations and correlations. Daily exposure and non-carcinogenic and carcinogenic risk were estimated. Sixty-eight scalp hair and 66 urine samples were taken from participants of different ages (6-17, 18-40, 41-60, and ≥ 65 years) living in the vicinity of an agricultural soil near mine and smelting areas. The results compared to the earlier studies showed an elevated concentration of Pb, Be, Bi, Co, Cr, Ni, Sb, and Zn in hair and urine. These heavy metals were more elevated in mining than in smelting. Considering gender differences, females were likely to be more affected than male. By investigating age differences in this area, high heavy metal concentrations in male's hair and urine existed in age of 18-40 and ≥ 66, respectively. However, females did not present homogeneous age distribution. Hair and urine showed a different distribution of heavy metals in different age and gender. In some cases, significant correlation was found between heavy metals in hair and urine (P > 0.05 and P > 0.01) in mining area. The estimated average daily intake of heavy metals in vegetables showed a great contribution compared to the soil and water. Non-carcinogenic and carcinogenic risk values of total pathways in mining and smelting areas were higher than 1 and exceeded the acceptable levels. Thus, the obtained data might be useful for further studies. They can serve as a basis of comparison and assessing the effect of simultaneous exposure from heavy metals in mining and smelting areas, and potential health risks from exposure to heavy metals in vegetables need more consideration.

  3. Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

    Directory of Open Access Journals (Sweden)

    William A Bennett

    2005-09-01

    Full Text Available The delta smelt (Hypomesus transpacificus is a small and relatively obscure fish that has recently risen to become a major focus of environmental concern in California. It was formally abundant in the low-salinity and freshwater habitats of the northeastern San Francisco Estuary, but is now listed as threatened under the Federal and California State Endangered Species Acts. In the decade following the listings scientific understanding has increased substantially, yet several key aspects of its biology and ecological relationships within the highly urbanized estuary remain uncertain. A key area of controversy centers on impacts to delta smelt associated with exporting large volumes of freshwater from the estuary to supply California’s significant agricultural and urban water demands. The lack of appropriate data, however, impedes efforts to resolve these issues and develop sound management and restoration alternatives. Delta smelt has an unusual life history strategy relative to many fishes. Some aspects of its biology are similar to other coastal fishes, particularly salmonids. Smelts in the genus, Hypomesus, occur throughout the Pacific Rim, have variable life history strategies, and are able to adapt rapidly to local environments. By comparison, delta smelt has a tiny geographic range being confined to a thin margin of low salinity habitat in the estuary. It primarily lives only a year, has relatively low fecundity, and pelagic larvae; life history attributes that are unusual when compared with many fishes worldwide. A small proportion of delta smelt lives two years. These individuals are relatively highly fecund but are so few in number that their reproductive contribution only may be of benefit to the population after years of extremely poor spawning success and survival. Provisioning of reproductive effort by these older fish may reflect a bet-hedging tactic to insure population persistence. Overall, the population persists by maximizing

  4. The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

    Science.gov (United States)

    Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

    2018-03-01

    The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

  5. Aspects of energy reduction by autogenous copper production in the copper smelting plant Bor

    International Nuclear Information System (INIS)

    Najdenov, Ivan; Raić, Karlo T.; Kokeza, Gordana

    2012-01-01

    This work presents a comparative analysis of the energy consumption during copper production by the “standard” procedure (roasting in a fluo–solid reactor and smelting in a reverberatory furnace) in the Smelting Plant in Bor with modern autogenous procedures. All forms of expended energy were reduced to primary energy or to the same energy form, i.e., to the energy equivalent of the process (EEP), the raw material and the process materials. In addition, the energy equivalent of the process and waste products (water vapour, thermal energy and similar) were balanced. To complete the consumption of all energy generating products in copper production, they were reduced to conditional fuel (coal equivalent = 29.3 MJ/kg). Additionally, this study suggests replacement of the existing technology by an appropriate autogenous procedure and considers the prospects for further development of mining and metallurgy in Bor. Estimates of development perspectives for copper production should be comprehensive, based on complete and relevant data, as well as on real considerations of future development in world production. -- Highlights: ► “Standard” autogenous copper production in the Smelting Plant, Bor, Serbia. ► Comparation of energy consumption in “standard” with other autogenous procedures. ► All forms of energy are reduced to energy equivalent and conditional fuel. ► Replacement of existing technology with the appropriate autogenous procedure. ► Perspectives of further development of mining and metallurgy in Bor.

  6. Inverse boundary design of a radiative smelting furnace with ablative phase change phenomena

    International Nuclear Information System (INIS)

    Farzan, H.; Hosseini Sarvari, S.M.; Mansouri, S.H.

    2016-01-01

    Highlights: • The ablation phenomenon in a reverberatory smelting furnace is simulated numerically. • The results are verified by comparing with exact analytic solution. • Inverse design problem is solved to construct the desired melting rate. • The conjugate gradient method is used to solve the inverse phase change problem. - Abstract: An inverse analysis is employed to control the time rate of heaters in a 2-D smelting furnace to provide the specified radiative heat flux across the design surface to establish a desired melting rate. The design surface in the smelting furnace is the melting surface of the metal concentrate bank, and the melting process is considered to occur as an ablation phenomenon. The net radiation method is used to determine the radiation exchange between the elements of the furnace surfaces and the melting surface. The conjugate gradient method is employed to minimize the objective function, which is the sum of square residuals between the estimated and the desired heat fluxes over the design surface. It is shown that the proposed inverse technique is reliable and accurate for predicting the heater power distribution.

  7. Thallium transformation and partitioning during Pb–Zn smelting and environmental implications

    International Nuclear Information System (INIS)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Xie, Xiaofan; Qi, Jianying; Lippold, Holger; Luo, Dinggui; Wang, Chunlin; Su, Longxiao; He, Lucheng; Wu, Qiwei

    2016-01-01

    Thallium (Tl) is a toxic and non-essential heavy metal. Raw Pb–Zn ores and solid smelting wastes from a large Pb–Zn smelting plant – a typical thallium (Tl) pollution source in South China, were investigated in terms of Tl distribution and fractionation. A modified IRMM (Institute for Reference Materials and Measurement, Europe) sequential extraction scheme was applied on the samples, in order to uncover the geochemical behavior and transformation of Tl during Pb–Zn smelting and to assess the potential environmental risk of Tl arising from this plant. Results showed that the Pb–Zn ore materials were relatively enriched with Tl (15.1–87.7 mg kg"−"1), while even higher accumulation existed in the electrostatic dust (3280–4050 mg kg"−"1) and acidic waste (13,300 mg kg"−"1). A comparison of Tl concentration and fraction distribution in different samples clearly demonstrated the significant role of the ore roasting in Tl transformation and mobilization, probably as a result of alteration/decomposition of related minerals followed by Tl release and subsequent deposition/co-precipitation on fine surface particles of the electrostatic dust and acidic waste. While only 10–30% of total Tl amounts was associated with the exchangeable/acid-extractable fraction of the Pb–Zn ore materials, up to 90% of total Tl was found in this fraction of the electrostatic dust and acidic waste. Taking into account the mobility and bioavailability of this fraction, these waste forms may pose significant environmental risk. - Highlights: • Geo-chemical partitioning of Tl in Pb–Zn ores and smelting wastes was investigated. • Significant differences were shown in Tl contents and chemical fractionation. • Over 100-fold enrichment of Tl was found in electrostatic dust and acidic waste. • Ore roasting played a key role in Tl transformation and mobilization. • Tl was mainly bound in the labile fraction of electrostatic dust and acidic waste. - Geo

  8. Contamination and human health risk of lead in soils around lead/zinc smelting areas in China.

    Science.gov (United States)

    Lei, Kai; Giubilato, Elisa; Critto, Andrea; Pan, Huiyun; Lin, Chunye

    2016-07-01

    Pb/Zn smelting, an important economic activity in China, has led to heavy environmental pollution. This research reviewed studies on soil Pb contamination at Pb/Zn smelting sites in China published during the period of 2000 to 2015 to clarify the total levels, spatial changes, and health risks for Pb contamination in soils at local and national scales. The results show that Pb contents in surface soils at 58 Pb/Zn smelting sites in China ranged from 7 to 312,452 mg kg(-1) with an arithmetic average, geometric average, and median of 1982, 404, and 428 mg kg(-1), respectively (n = 1011). Surface soil Pb content at these smelting sites decreased from an average of 2466 to 659 mg kg(-1), then to 463 mg kg(-1) as the distance from the smelters increased from 2000 m. With respect to variation with depth, the average soil Pb content at these sites gradually decreased from 986 mg kg(-1) at 0- to 20-cm depth to 144 mg kg(-1) at 80- to 100-cm depth. Approximately 78 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites were classified as having high Pb pollution levels. Approximately 34.2 and 7.7 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites might pose adverse health effects and high chronic risks to children, respectively. The Pb/Zn smelting sites in the southwest and southeast provinces of China, as well as Liaoning province, were most contaminated and thus should receive priority for remediation.

  9. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Directory of Open Access Journals (Sweden)

    Tang, Qifeng

    2016-06-01

    Full Text Available The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al2O3/SiO2, the addition of CaF2, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol-1.En este trabajo se estudia la reducción de óxido de magnesio. La influencia de la composición de las escorias y de la temperatura de reducción sobre el porcentaje de reducción de óxido de magnesio han sido discutidas, y asimismo se ha estudiado la cinética de la reducción del óxido de magnesio en escorias fundidas. Los resultados muestran que la reducción se incrementa al aumentar alguno de los siguientes factores: la proporción de Al2O3/SiO2, la adición de CaF2, la proporción molar de Si/2MgO y la temperatura de reacción. En general la reducción fue controlada por la transferencia de masa en la escoria con una energía aparente de 586 kJ mol-1.

  10. Thallium transformation and partitioning during Pb-Zn smelting and environmental implications.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Xie, Xiaofan; Qi, Jianying; Lippold, Holger; Luo, Dinggui; Wang, Chunlin; Su, Longxiao; He, Lucheng; Wu, Qiwei

    2016-05-01

    Thallium (Tl) is a toxic and non-essential heavy metal. Raw Pb-Zn ores and solid smelting wastes from a large Pb-Zn smelting plant - a typical thallium (Tl) pollution source in South China, were investigated in terms of Tl distribution and fractionation. A modified IRMM (Institute for Reference Materials and Measurement, Europe) sequential extraction scheme was applied on the samples, in order to uncover the geochemical behavior and transformation of Tl during Pb-Zn smelting and to assess the potential environmental risk of Tl arising from this plant. Results showed that the Pb-Zn ore materials were relatively enriched with Tl (15.1-87.7 mg kg(-1)), while even higher accumulation existed in the electrostatic dust (3280-4050 mg kg(-1)) and acidic waste (13,300 mg kg(-1)). A comparison of Tl concentration and fraction distribution in different samples clearly demonstrated the significant role of the ore roasting in Tl transformation and mobilization, probably as a result of alteration/decomposition of related minerals followed by Tl release and subsequent deposition/co-precipitation on fine surface particles of the electrostatic dust and acidic waste. While only 10-30% of total Tl amounts was associated with the exchangeable/acid-extractable fraction of the Pb-Zn ore materials, up to 90% of total Tl was found in this fraction of the electrostatic dust and acidic waste. Taking into account the mobility and bioavailability of this fraction, these waste forms may pose significant environmental risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Environmental impact of early Basque mining and smelting recorded in a high ash minerogenic peat deposit

    International Nuclear Information System (INIS)

    Monna, F.; Galop, D.; Carozza, L.; Tual, M.; Beyrie, A.; Marembert, F.; Chateau, C.; Dominik, J.; Grousset, F.E.

    2004-01-01

    More than four metres of core, covering almost 5000 years of deposition, were collected in a high ash minerogenic peat deposit located in the High Aldudes valley (Basque country), an area well known for its mineral abundance, exploited from Roman Times at least. Although minerogenic peatlands are not generally considered as the best archives to reconstruct past atmospheric metal deposition history, lead isotopic geochemistry demonstrates the integrity of the Pb record at least within the three upper meters; that is to say over the last four millennia. Zn, Cd and Cu may have been widely redistributed either by biological cycling, advective groundwater movements, or diffusional processes. Anthropogenic lead input phases are clearly pinpointed by positive shifts in Pb/Sc ratios with concomitant sharp drops in 206 Pb/ 207 Pb ratios. They are often accompanied by significant declines in tree taxa, interpreted as increasing demand for wood to supply energy for local mining and/or metallurgical operations. Periods of mining and/or smelting activity are identified during Antiquity and Modern Times, and are also confirmed by textual and field evidence. Inputs from the Rio Tinto (Southern Spain), often invoked as a major lead contributor to the European atmosphere during Roman Times, were not detected here. This remote source was probably masked by local inputs. Other mining and/or smelting phases, only suspected by archaeologists, are here identified as early as the Bronze Age. Although the durations of these phases are possibly overestimated because of detrital inputs consequent to the release of lead from polluted soils over a long period of time after major pollutant inputs, the periods at which pollution peaks occur are in good agreement with archaeological knowledge and palaeo-botanical data. The combination of geochemical and palaeo-botanical techniques with field archaeology, therefore provides a powerful tool in studying the interaction of early human societies with

  12. Distinguishing between native and smelted coppers using PIXE spectrometry: a case history from early colonial America

    International Nuclear Information System (INIS)

    Fleming, S.J.; Swann, C.P.

    2000-01-01

    During the recent excavation of a native American village at Governor's Land, in Virginia, two burials were unearthed, each of which contained a jumble of human bones, some fabric and a large number of copper tube beads. PIXE analysis of a representative group of these beads showed that about one-third of them were shaped from pieces of native copper, while the remainder were fashioned from scraps of smelted copper. Since the latter must have come from Europe, these data place the village's occupation in the decade either side of A.D. 1607, when the English first settled at nearby Jamestown

  13. Reduction electric smelting of ferriferrous-titanium concentrates from Gremyakha-Vyrmes deposit

    International Nuclear Information System (INIS)

    Morozov, A.A.

    2002-01-01

    Substantial composition of ilmenite and titanium-magnetite concentrates from Gremyaha-Vyrmes deposit is studied and their reducibility is examined as compared with other similar kids of raw materials. Thermal-physical properties of slag melts (such as toughness and melting ability), formed in reduction smelting of the above-mentioned concentrates for different reduction degree, are determined. These properties characterize the electric thermal transformation process of concentrates as hi-tech one. Features of chemical composition of metal, which is naturally alloyed with vanadium and is produced at the same time are noted. This metal expands the possibilities of complex used of the concentrates of this deposit [ru

  14. Fate of recovery boiler smelt nitrogen in the recovery cycle; Soodakattilan sulan typpiyhdisteitten kaeyttaeytyminen talteenottoprosessissa

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Forssen, M.; Backman, R.; Ek, P.; Hulden, S.G.; Kilpinen, P.; Kymaelaeinen, M.; Malm, H. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1997-10-01

    The purpose of this project is to study the fate of the nitrogen bound in the inorganic smelt after it enters the dissolving tank. Of special interest is to find in what form this nitrogen can be found further down in the recovery process and especially in what form it can be removed from the process. The aim is to clarify if the nitrogen can be a potential problem in the process or if it can become a potential emission. The work is divided into choosing methods for the analysis of different nitrogen species, collection and analysis of mill samples, laboratory studies and theoretical studies on nitrogen chemistry in alkaline solutions and reporting

  15. A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Ted Sommer

    2013-06-01

    Full Text Available We used a combination of published literature and field survey data to synthesize the available information about habitat use by delta smelt Hypomesus transpacificus, a declining native species in the San Francisco Estuary. Delta smelt habitat ranges from San Pablo and Suisun bays to their freshwater tributaries, including the Sacramento and San Joaquin rivers. In recent years, substantial numbers of delta smelt have colonized habitat in Liberty Island, a north Delta area that flooded in 1997. The species has a more upstream distribution during spawning as opposed to juvenile rearing periods. Post-larvae and juveniles tend to have a more downstream distribution during wetter years. Delta smelt are most common in low-salinity habitat (<6 psu with high turbidities (>12 NTU and moderate temperatures (7 °C to 25 °C. They do not appear to have strong substrate preferences, but sandy shoals are important for spawning in other osmerids. The evidence to date suggests that they generally require at least some tidal flow in their habitats. Delta smelt also occur in a wide range of channel sizes, although they seem to be rarer in small channels (<15 m wide. Nonetheless, there is some evidence that open water adjacent to habitats with long water-residence times (e.g. tidal marsh, shoal, low-order channels may be favorable. Other desirable features of delta smelt habitat include high calanoid copepod densities and low levels of submerged aquatic vegetation (SAV and the toxic algae Microcystis. Although enough is known to plan for large-scale pilot habitat projects, these efforts are vulnerable to several factors, most notably climate change, which will change salinity regimes and increase the occurrence of lethal temperatures. We recommend restoration of multiple geographical regions and habitats coupled with extensive monitoring and adaptive management. An overall emphasis on ecosystem processes rather than specific habitat features is also likely to be

  16. Cold-rolled sheets production of stainless martensite-ageing steel smelted by vacuum arc and electroslag techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, A A; Grishkov, A I; Suslin, A P; Nesterenko, A A; Lola, V N [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

    1975-05-01

    In cooperation with a number of metallurgical works the production of a high strength sheet stainless maraging steel EHP678 (000KH11N10M2T) has been tested by rolling cylindrical ingots of vacuum arc smelting at the blooming (the mass of rough ingots was 5.1 to 6.0 t, that of cleaned ingots - 3.8 to 5.1 t) or rectangular ingots of electroslag smelting (13 t) at the slabbing. The recommended regimes of heating and deformation are much similar to those used for the steel-KH18N10T. The output of valid cold-rolled sheets proved to be rather low (0.24 t/t for the vacuum arc smelting and 0.30 t/t for the electroslag smelting) mainly due to the losses on cleaning and a considerable portion of wrong-size slabs. The data are presented on the steel-EHP678 properties after various heat treatments. For the production of wide cold-rolled sheets of the steel EHP678 it is recommended to use steelmaking procedure with electroslag smelting including open-hearth melting in arc furnaces, rolling of ingots at the slabbing with heating up to 1260-1280 deg C (hold-up of 4.5 to 5 hrs); electroslag smelting for rectangular section slabs, rolling of ingots of electroslag smelting at the slabbing with their heating up to 1250 deg C (hold-up of 5.5 to 6 hrs), rolling at the 1680-type mill with heating up to 1250-1260 deg C (hold-up of 4 to 4.5 hrs ensuring the rolling temperature after a rough group not below 1100 deg C), quenching of hot-rolled sheets heating up to 920-940 deg C (hold-up of 3 to 3.5 min/mm), shot peening of sheets for descaling (provided the respective equipment is available) with a subsequent short-time pickling in an acid solution and cold rolling with a summary deformation of 35 to 45 %. The steelmaking with the electroslag smelting is much more profitable as regards to the fine technology of number of the main procedures, convenient cooperation of the works and a considerably greater output of the final products out of one ton of the steel produced.

  17. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    OpenAIRE

    Guo, Lijie; Li, Wenchen; Yang, Xiaocong; Xu, Wenyuan

    2018-01-01

    This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS) on cemented tailing backfill (CTB) that contains lead-zinc smelting slag. CTB and cemented paste (CP) containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis a...

  18. Connectivity between Migrating and Landlocked Populations of a Diadromous fish Species Investigated Using Otolith Microchemistry

    NARCIS (Netherlands)

    Tulp, I.Y.M.; Keller, A.M.; Navez, J.; Winter, H.V.; Graaf, de M.; Baeyens, W.

    2013-01-01

    Smelt Osmerus eperlanus has two different life history strategies in the Netherlands. The migrating population inhabits the Wadden Sea and spawns in freshwater areas. After the closure of the Afsluitdijk in 1932, part of the smelt population became landlocked. The fresh water smelt population has

  19. Investigation of the particulate derived from indigenous zinc smelting using the nuclear analytical technique

    International Nuclear Information System (INIS)

    Zhu Guanghua

    1995-12-01

    The air particulate samples at the site of indigenous zinc smelting in south of China, using an 8-stage cascade impactor have been collected. The elemental concentrations of the samples were analyzed by PIXE (Particle Induced X-ray Emission) method. As a result, the mass concentrations of more than 17 elements and their size distribution spectra were obtained. Then the data were analyzed by the absolute principal component analysis (APCA) to evaluate principal components and the percent variance explained by them. From the elemental size distribution spectra, three kinds of patterns were found that they corresponded to the tree principal components and suggested that they were from ore vapor, coal burning and soil dust. Based on the elemental size distribution spectra and a deposit model the deposited amounts for several elements in a human's lung during a day were calculated and compared with that of other places. It is shown that the air quality was heavily degraded at the site of indigenous zinc smelting. (5 refs., 3 figs., 2 tabs.)

  20. Modelling of chalcopyrite oxidation reactions in the Outokumpu flash smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Ahokainen, T.; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1996-12-31

    A mathematical model for simulating oxidation reactions of chalcopyrite particles together with momentum, heat and mass transfer between particle and gas phase in a flash smelting furnace reaction shaft is presented. In simulation, the equations governing the gas flow are solved numerically with a commercial fluid flow package, Phoenics. The particle phase is introduced into the gas flow by a Particle Source In Cell (PSIC) - technique, where a number of discrete particles is tracked in a gas flow and the relevant source terms for momentum, mass, and heat transfer are added to the gas phase equations. The gas phase equations used are elliptic in nature and the fluid turbulence is described by the (k-{epsilon}) -model. Thermal gas phase radiation is simulated with a six-flux radiation model. The chemical reactions of concentrate particles are assumed to happen at two sharp interfaces, and a shrinking core model is applied to describe the mass transfer of chemical species through the reaction product layer. In a molten state, the oxygen consumption is controlled by a film penetration concept. The reacting concentrate particles are a mixture of chalcopyrite and silica. Also a certain amount of pure inert silica is fed to the process as flux. In the simulations the calculation domain includes the concentrate burner and a cylindrical reaction shaft of an industrial scale flash smelting furnace. Some examples about the simulations carried out by the combustion model are presented. (author)

  1. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    International Nuclear Information System (INIS)

    Aminatun,; Putri, N.S Efinda; Indriani, Arista; Himawati, Umi; Hikmawati, Dyah; Suhariningsih

    2014-01-01

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis

  2. Smelting of high-quality boiler steel in large-load arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Kablukovskij, A F; Breus, V M; Tyurin, E I; Khristich, V D; Dumchev, Ya P [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

    1975-02-01

    High-grade steel can be obtained in large-capacity furnaces if the smelting technology used takes account of the size of the aggregates, the course of the metal fusion process, interaction with slag, furnace atmosphere, reducing agents, and other process characteristics. 12Kh1MF boiler steel smelted in a 100-ton electric arc furnace by an oxidizing process with oxygen bath blow and cast by the siphon method into 6.5-ton ingots using a slag-forming mixture (240 mm diameter billets and 219 to 245 mm diameter tubes) is satisfactory with regard to macro and microstructure, oxygen and nonmetallic oxide inclusion content, and mechanical properties. The stress rupture strength of 10/sup 5/ h at 570/sup 0/C is similar to that of open-hearth steel. Sulfides larger than a 3.5 spheroid have been detected in it. The nitrogen content of the electric steel is 0.0090 to 0.0120%, which is somewhat greater than usual in open-hearth metal. Of the oxygen inclusions in the steel, spinel-alumina predominates. Large inclusions were represented mainly by brittle silicates which appeared to be of exogenous origin.

  3. Application of PAH concentration profiles in lake sediments as indicators for smelting activity.

    Science.gov (United States)

    Warner, Wiebke; Ruppert, Hans; Licha, Tobias

    2016-09-01

    The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Modelling of chalcopyrite oxidation reactions in the Outokumpu flash smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Ahokainen, T; Jokilaakso, A [Helsinki Univ. of Technology, Otaniemi (Finland)

    1997-12-31

    A mathematical model for simulating oxidation reactions of chalcopyrite particles together with momentum, heat and mass transfer between particle and gas phase in a flash smelting furnace reaction shaft is presented. In simulation, the equations governing the gas flow are solved numerically with a commercial fluid flow package, Phoenics. The particle phase is introduced into the gas flow by a Particle Source In Cell (PSIC) - technique, where a number of discrete particles is tracked in a gas flow and the relevant source terms for momentum, mass, and heat transfer are added to the gas phase equations. The gas phase equations used are elliptic in nature and the fluid turbulence is described by the (k-{epsilon}) -model. Thermal gas phase radiation is simulated with a six-flux radiation model. The chemical reactions of concentrate particles are assumed to happen at two sharp interfaces, and a shrinking core model is applied to describe the mass transfer of chemical species through the reaction product layer. In a molten state, the oxygen consumption is controlled by a film penetration concept. The reacting concentrate particles are a mixture of chalcopyrite and silica. Also a certain amount of pure inert silica is fed to the process as flux. In the simulations the calculation domain includes the concentrate burner and a cylindrical reaction shaft of an industrial scale flash smelting furnace. Some examples about the simulations carried out by the combustion model are presented. (author)

  5. Thermodynamic Analysis of Oxygen-Enriched Direct Smelting of Jamesonite Concentrate

    Science.gov (United States)

    Zhang, Zhong-Tang; Dai, Xi; Zhang, Wen-Hai

    2017-12-01

    Thermodynamic analysis of oxygen-enriched direct smelting of jamesonite concentrate is reported in this article. First, the occurrence state of lead, antimony and other metallic elements in the smelting process was investigated theoretically. Then, the verification test was carried out. The results indicate that lead and antimony mainly exist in the alloy in the form of metallic lead and metallic antimony. Simultaneously, lead and antimony were also oxidized into the slag in the form of lead-antimony oxide. Iron and copper could be oxidized into the slag in the form of oxides in addition to combining with antimony in the alloy, while zinc was mainly oxidized into the slag in the form of zinc oxide. The verification test indicates that the main phases in the alloy contain metallic lead, metallic antimony and a small amount of Cu2Sb, FeSb2 intermetallic compounds, and the slag is mainly composed of kirschsteinite, fayalite and zinc oxide, in agreement with the thermodynamic analysis.

  6. Two-Dimensional Physical and CFD Modelling of Large Gas Bubble Behaviour in Bath Smelting Furnaces

    Directory of Open Access Journals (Sweden)

    Yuhua Pan

    2010-09-01

    Full Text Available The behaviour of large gas bubbles in a liquid bath and the mechanisms of splash generation due to gas bubble rupture in high-intensity bath smelting furnaces were investigated by means of physical and mathematical (CFD modelling techniques. In the physical modelling work, a two-dimensional Perspex model of the pilot plant furnace at CSIRO Process Science and Engineering was established in the laboratory. An aqueous glycerol solution was used to simulate liquid slag. Air was injected via a submerged lance into the liquid bath and the bubble behaviour and the resultant splashing phenomena were observed and recorded with a high-speed video camera. In the mathematical modelling work, a two-dimensional CFD model was developed to simulate the free surface flows due to motion and deformation of large gas bubbles in the liquid bath and rupture of the bubbles at the bath free surface. It was concluded from these modelling investigations that the splashes generated in high-intensity bath smelting furnaces are mainly caused by the rupture of fast rising large gas bubbles. The acceleration of the bubbles into the preceding bubbles and the rupture of the coalescent bubbles at the bath surface contribute significantly to splash generation.

  7. Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

    Science.gov (United States)

    Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

    2017-01-01

    The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

  8. The recovery of Zn and Pb and the manufacture of lightweight bricks from zinc smelting slag and clay.

    Science.gov (United States)

    Hu, Huiping; Deng, Qiufeng; Li, Chao; Xie, Yue; Dong, Zeqin; Zhang, Wei

    2014-04-30

    Novel lightweight bricks have been produced by sintering mixes of zinc smelting slag and clay. A two-stage sintered process has been proposed to recovery of Zn and Pb and reutilization of the zinc smelting slag. In the first stage of the process, called reduction and volatilization procedure, zinc and lead were reduced by the carbon contained in the zinc smelting slag and volatilized into the dust, and the dust can be used as a secondary zinc resource. In the second stage of the process, called oxidation sintering procedure, a lightweight brick was produced. Samples containing up to 60 wt.% zinc smelting slag and 40 wt.% kaolin clay were reduced at 1050°C for 6h, and then sintered at 1050°C for 4h. The recoveries of Zn and Pb from the brick are 94.5 ± 0.6% and 97.6 ± 0.2%, respectively. Low bulk density (1.42 g cm(-3)) and relatively high compressive strength (2 2MPa) sintered bricks were produced, and the leaching toxicity of the sintered bricks was below the regulatory thresholds of Chinese National Standards. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Diet, Prey Selection, and Body Condition of Age-0 Delta Smelt, Hypomesus transpacificus, in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Steven B. Slater

    2014-09-01

    Full Text Available Steven B. Slater and Randall D. Baxterdoi: http://dx.doi.org/10.15447/sfews.2014v12iss3art1The Delta Smelt, an endangered fish, has suffered a long-term decline in abundance, believed to result from, in part, to changes in the pelagic food web of the upper San Francisco Estuary. To investigate the current role of food as a factor in Delta Smelt well-being, we developed reference criteria for gut fullness and body condition based on allometric growth. We then examined monthly diet, prey selectivity, and gut fullness of larvae and juvenile Delta Smelt collected April through September in 2005 and 2006 for evidence of feeding difficulties leading to reduced body condition. Calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi remained major food items during spring and from early summer through fall, respectively. Other much larger copepods and macroinvertebrates contributed in lesser numbers to the diet of older juvenile fish from mid-summer through fall. In fall, juvenile Delta Smelt periodically relied heavily on very small prey and prey potentially associated with demersal habitat, suggesting typical pelagic food items were in short supply. We found a strong positive selection for E. affinis and P. forbesi, neutral to negative selection for evasive calanoid Sinocalanus doerrii, and neutral to negative selection for the small cyclopoid copepod Limnoithona tetraspina and copepod nauplii, which were consumed only when extremely numerous in the environment. Feeding incidence was significantly higher in 2006, but among successfully feeding fish we found no between year difference in gut fullness. However, we did detect differences in fullness across months in both years. We found no difference in body condition of Delta Smelt between years yet our sample sizes were low in September when Delta Smelt reverted to feeding on very small organisms and fullness declined, so the longer-term effect remains unknown. Our findings suggest that: Delta

  10. Trace element partitioning and soil particle characterisation around mining and smelting areas at Tharsis, Riotinto and Huelva, SW Spain

    Energy Technology Data Exchange (ETDEWEB)

    Chopin, E.I.B. [School of Human and Environmental Sciences, University of Reading (United Kingdom)]. E-mail: edith.chopin@univ-reims.fr; Alloway, B.J. [School of Human and Environmental Sciences, University of Reading (United Kingdom)

    2007-02-15

    Trace elements may present an environmental hazard in the vicinity of mining and smelting activities. However, the factors controlling trace element distribution in soils around ancient and modern mining and smelting areas are not always clear. Tharsis, Riotinto and Huelva are located in the Iberian Pyrite Belt in SW Spain. Tharsis and Riotinto mines have been exploited since 2500 B.C., with intensive smelting taking place. Huelva, established in 1970 and using the Flash Furnace Outokumpu process, is currently one of the largest smelter in the world. Pyrite and chalcopyrite ore have been intensively smelted for Cu. However, unusually for smelters and mines of a similar size, the elevated trace element concentrations in soils were found to be restricted to the immediate vicinity of the mines and smelters, being found up to a maximum of 2 km from the mines and smelters at Tharsis, Riotinto and Huelva. Trace element partitioning (over 2/3 of trace elements found in the residual immobile fraction of soils at Tharsis) and soil particles examination by SEM-EDX showed that trace elements were not adsorbed onto soil particles, but were included within the matrix of large trace element-rich Fe silicate slag particles (i.e. 1 mm o at least 1 wt.% As, Cu and Zn, and 2 wt.% Pb). Slag particle large size (1 mm o) was found to control the geographically restricted trace element distribution in soils at Tharsis, Riotinto and Huelva, since large heavy particles could not have been transported long distances. Distribution and partitioning indicated that impacts to the environment as a result of mining and smelting should remain minimal in the region.

  11. Polychlorinated dibenzo-p-dioxin and dibenzofuran and polychlorinated biphenyl emissions from different smelting stages in secondary copper metallurgy.

    Science.gov (United States)

    Hu, Jicheng; Zheng, Minghui; Nie, Zhiqiang; Liu, Wenbin; Liu, Guorui; Zhang, Bing; Xiao, Ke

    2013-01-01

    Secondary copper production has received much attention for its high emissions of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) reported in previous studies. These studies focused on the estimation of total PCDD/F and polychlorinated biphenyl (PCB) emissions from secondary copper smelters. However, large variations in PCDD/F and PCB emissions reported in these studies were not analyzed and discussed further. In this study, stack gas samples at different smelting stages (feeding-fusion, oxidation and deoxidization) were collected from four plants to investigate variations in PCDD/F and PCB emissions and characteristics during the secondary copper smelting process. The results indicate that PCDD/F emissions occur mainly at the feeding-fusion stage and these emissions contribute to 54-88% of the total emissions from the secondary copper smelting process. The variation in feed material and operating conditions at different smelting stages leads to the variation in PCDD/F emissions during the secondary copper smelting process. The total PCDD/F and PCB discharge (stack gas emission+fly ash discharge) is consistent with the copper scrap content in the raw material in the secondary copper smelters investigated. On a production basis of 1 ton copper, the total PCDD/F and dl-PCB discharge was 102, 24.8 and 5.88 μg TEQ t(-1) for the three plants that contained 100%, 30% and 0% copper scrap in their raw material feed, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  13. Trace elements in rainwater and dry deposition around a smelting complex

    Energy Technology Data Exchange (ETDEWEB)

    Beavington, F

    1977-06-01

    A number of plastic raingauges were set up at various distances around a smelting complex (copper smelter and steelworks) in Wollongong, Australia, to determine the pattern of total atmospheric deposition (rainwater and dry deposition) of copper, zinc, lead, cadmium, iron and manganese. At the site nearest the smelter, total deposition of these metals (6N HCl soluble) in kg/ha over a period of twelve months was 30.7 copper, 8.4 zinc, 4.7 lead, 0.19 cadmium, 42.6 iron and 1.5 manganese. These levels were considerably higher than at a distant rural site where background levels were similar to those reported for the United Kingdom. The pattern of deposition of metals over Wollongong accords with levels of metals previously reported in surface soil, herbage and leaf vegetables.

  14. Lance for fuel and oxygen injection into smelting or refining furnace

    Science.gov (United States)

    Schlichting, Mark R.

    1994-01-01

    A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

  15. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    Directory of Open Access Journals (Sweden)

    Savic Marija V.

    2015-09-01

    Full Text Available This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA, artificial neural networks (ANNs and adaptive network based fuzzy inference system (ANFIS were used as tools for mathematical analysis of the indicated problem. The best correlation coefficient (R2 = 0.719 of the final model was obtained using the ANFIS modeling approach.

  16. Geochemical Study on an Abandoned Copper Smelting Plant Using Rare Earth Elements

    Science.gov (United States)

    Sun, S. H.

    2017-12-01

    The Shuei Nan Dong Copper Smelting Plant smelting is located on the northern coast of New Taipei City, Taiwan. The plant built in 1906 for but has been shut down since 1987. However, the watershed is continuing to discharge acid mine water into the sea; and, the acid mine drainage releases high amounts of sulfate, heavy metals without any treatment. In this study, the water samples were sequentially collected along the main channel and its tributaries in the watershed. The results of hydrochemical analysis show that the untreated inflow water can be characterized with low pH value of 80% of the total variance and almost all chemical components have high loadings in the PC. Therefore, the hydrochemical properties in the watershed are mainly dominated by the mixing process between main channel and the major tributary but the geochemical reactions during flow down the channel is insignificant. Rare earth elements (REE) are an excellent tracer, which can indicate sources of chemical components and geochemical reactions in water. The analysis results demonstrate two distinct REE patterns. The water with low REE can be characterized by prominent Eu positive anomaly and Ce negative anomaly, which may result from the alteration of Na-plagioclase in sandstone and oxidation reaction when contact with air, respectively. On the contrary, the water with high REE shows only minor Ce negative anomaly and insignificant Eu positive anomaly. In addition, there is an enrichment of middle REE in high-REE water, which is quite different with the REE pattern of pyrite. According to the Grawunder's study (2014), it corresponds to the complexation to sulphite during pyrite oxidation. It is worth noting that REE show no considerable fractionation along the channel and confirms the results from PCA. It can be derived that the water may not reached equilibrium condition. A simple aerated retention pool could dramatically reduce the pollutants due to coprecipitation of iron oxide and aluminum

  17. Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.

    Science.gov (United States)

    Zajicek, J.L.; Brown, L.; Brown, S.B.; Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.

    2009-01-01

    The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (> or = 90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5-6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus-derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.

  18. Pollution level and inhalation exposure of ambient aerosol fluoride as affected by polymetallic rare earth mining and smelting in Baotou, north China

    Science.gov (United States)

    Zhong, Buqing; Wang, Lingqing; Liang, Tao; Xing, Baoshan

    2017-10-01

    Airborne fluoride associated with total suspended particles (TSP) and respirable particulate (PM10) in the rare earth mining and smelting areas were analyzed during August 2012 and March 2013. In March, average concentrations of fluoride bound to TSP in the mining and smelting areas were 0.598 ± 0.626 μg/m3 and 3.615 ± 4.267 μg/m3, respectively, whereas that in August were 0.699 ± 0.801 μg/m3 and 1.917 ± 2.233 μg/m3, respectively. TSP samples were classified into four categories by different sampling periods and locations using Kohonen's self-organizing map, which demonstrates that high airborne fluoride concentrations in March in the smelting area were probably attributed to industrial emissions from smelting activities and wind-blown dust from tailings pond, influenced by meteorologic parameters such as temperature, relative humidity, precipitation and wind speed. The mean daily amount of fluoride inhaled in the mining and smelting areas were estimated to be in the range of 2.77-57.61 μg/day and 3.39-64.32 μg/day, respectively. These results indicate the high potential exposure level of fluoride inhaled for local residents in the polymetallic mining and smelting areas.

  19. EAF smelting trials of waste-carbon briquettes at Avesta Works of Outokumpu Stainless AB for recycling oily mill scale sludge from stainless steel production

    Energy Technology Data Exchange (ETDEWEB)

    Yang Qixing; Bjoerkman, Bo [Div. of Process Metallurgy, Lulea Univ. of Tech., Lulea (Sweden); Holmberg, Nils [Raw Materials Handling, Avesta Works, Outokumpu Stainless AB, Avesta (Sweden)

    2009-06-15

    The EAF steel plant of Avesta Works, Outokumpu Stainless AB, has been used to perform smelting reduction trials of briquettes consisting of oily mill scale sludge, carbon and other wastes. A total of 7 briquette smelting trials were performed. The heats were processed smoothly smelting 3 t of briquettes or 3.4 mass-% of metal charges. The quantities of FeSi powder and O{sub 2} gas injected and electric energy supplied were increased to smelt briquettes of 6 t. No impacts were found on the analyses of the crude stainless steel tapped from the EAF during the trials. The results of the briquette smelting have been evaluated by referring to the data from the reference heats and results from earlier laboratory tests. The recovery of Cr, Ni and Fe elements from the briquettes was nearly complete and was found to occur mainly through carbon reduction. The slag masses were not increased in three trials as compared with the reference heats. There were moderate increases in the slag masses in four trial heats. The increases were, nevertheless, lower by 52-69% than the slag masses generated by Si-reduction of the briquette oxides. Afterwards, by referring results from the present trials, waste-carbon briquettes amounting to 1-3 t were smelted very smoothly in many of the EAF heats at Avesta Works to recycle the oily mill scale sludge and other wastes from stainless steel production. (orig.)

  20. Toxic metal levels in children residing in a smelting craft village in Vietnam: a pilot biomonitoring study.

    Science.gov (United States)

    Sanders, Alison P; Miller, Sloane K; Nguyen, Viet; Kotch, Jonathan B; Fry, Rebecca C

    2014-02-04

    In Vietnam, environmental pollution caused by small-scale domestic smelting of automobile batteries into lead ingot is a growing concern. The village of Nghia Lo is a smelting craft village located roughly 25 km southeast of Hanoi in the Red River Delta. Despite the concern of toxic metal exposure in the village, biomonitoring among susceptible populations, such as children, has not been previously conducted. The aim of this study was to determine the body burden of toxic metals in children residing in a smelting craft village. Twenty children from Nghia Lo, Vietnam, ages 18 months to four years were selected for capillary whole blood and toenail biomonitoring. Whole blood lead levels (BLLs) were measured using a portable lead analyzer, and toenail levels of arsenic, cadmium, chromium, lead, manganese, and mercury were analyzed with inductively coupled plasma-mass spectrometry. The findings show that all of the 20 children had detectable BLLs, and every child had levels that exceeded the Centers for Disease Control and Prevention guideline level of 5 μg/dL. Eighty percent of tested subjects had BLLs higher than 10 μg/dL. Five children (25%) had BLLs greater than 45 μg/dL, the level of recommended medical intervention. In addition to blood lead, all of the children had detectable levels of arsenic, cadmium, chromium, lead, manganese, and mercury in toenail samples. Notably, average toenail lead, manganese, and mercury levels were 157 μg/g, 7.41 μg/g, and 2.63 μg/g respectively, well above levels previously reported in children. Significant Spearman's rank correlations showed that there were relationships between blood and toenail lead levels (r = 0.65, p craft villages in Vietnam are co-exposed to toxic metals. There is an urgent need for mitigation to control metal exposure related to domestic smelting.

  1. Patterns of recruitment of the sand smelt (Atherina presbyter on rocky intertidal habitats

    Directory of Open Access Journals (Sweden)

    Frederico Almada

    2015-11-01

    Full Text Available The Portuguese coast is located in a biogeographical transition zone between temperate and subtropical waters making it especially vulnerable to the effects of climate change. Several fish species struggle to cope with these annual changing conditions, particularly species that strongly depend on intertidal habitats which are expected to endure higher ecological fluctuations. Sand smelt young recruits and larvae were collected at the west coast of Portugal in the intertidal by hand-netting, and in the subtidal with light traps and scuba diving with plankton nets attached to scooters (Parede/Avencas: 38º 41’ N, 9º 21’W and Arrábida: 38º 28’ N, 8º 59’W, respectively. Due to the morphological similarities with other congeneric species young specimens were regularly collected and identified through genetic analysis. All samples were assigned to the same species: A. presbyter. Results showed that A. presbyter is one of the most abundant non-resident fish species in these rocky coastal areas, representing 49% (n=93.958 of the total number of individuals sighted in the intertidal from 2009-2015, but only 0.55% of the total number of individuals sampled in the subtidal (n=176 with both methods from 2011-2013. Distribution patterns showed that recruits (TL 0.8-6.8 cm concentrated within the intertidal area between March and December. Younger cohorts (TL 0.8-1.2 cm are captured almost exclusively in these areas including confined intertidal channels and large pools between March and August, suggesting that reproduction and spawning can occur for a period of 6 months. Inter-annual seasonal variations from 2009 to 2015 showed irregular water temperature profiles, especially in 2011 and 2012, which may dramatically affect the reproductive success of this species, not only reducing the number of recruits but also shortening the recruitment period from 10 to 5 months. Globally, 46% of the coastlines have experienced a significant decrease in the

  2. Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

    2013-01-01

    Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

  3. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    International Nuclear Information System (INIS)

    Balakhovskaya, M.B.; Khusainova, N.A.; Davlyatova, L.N.

    1975-01-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at - 40 deg C, while the open-hearth one becomes brittle as early as at - 20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm 2 show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples

  4. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Balakhovskaya, M B; Khusainova, N A; Davlyatova, L N [Vsesoyuznyj Nauchno-Issledovatel' skij Teplotekhnicheskij Inst., Moscow (USSR)

    1975-12-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at /sup -/40 deg C, while the open-hearth one becomes brittle as early as at /sup -/20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm/sup 2/ show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples.

  5. Atmospheric thorium pollution and inhalation exposure in the largest rare earth mining and smelting area in China.

    Science.gov (United States)

    Wang, Lingqing; Zhong, Buqing; Liang, Tao; Xing, Baoshan; Zhu, Yifang

    2016-12-01

    Exposure to radionuclide thorium (Th) has generated widespread public concerns, mainly because of its radiological effects on human health. Activity levels of airborne 232 Th in total suspended particulate (TSP) were measured in the vicinity of the largest rare earth mine in China in August 2012 and March 2013. The mean activity concentrations of 232 Th in TSP ranged from 820μBqm -3 in a mining area in August 2012 to 39,720μBqm -3 in a smelting area in March 2013, much higher than the world reference of 0.5μBqm -3 . Multistatistical analysis and Kohonen's self-organizing maps suggested that 232 Th in TSP was mainly derived from rare earth mining and smelting practices. In addition, personal inhalation exposures to 232 Th associated with respirable particulate (PM 10 ) were also measured among local dwellers via personal monitoring. The mean dose values for different age groups in the smelting and mining areas ranged from 97.86 to 417μSvyear - 1 and from 101.03 to 430.83μSvyear -1 , respectively. These results indicate that people living in the study areas are exposed to high levels of widespread 232 Th. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Industrial activity, gas emissions and environmental urban management. Operative condition's diagnostic of smelting activities in Tandil, Argentina

    International Nuclear Information System (INIS)

    Soledad Sosa, Beatriz; Guerrero, Elsa Marcela; Banda Noriega, Roxana

    2013-01-01

    Amongst urban environmental problems, those associated to industry are of particular interest in environmental management. Tandil, a city in Argentina, owes its economic and urban growth to metalworking activity, especially to smelting. Despite the crisis in the sector, activity continues to be the axis of local economic and urban growth. The present research characterizes, in production, operative and environmental terms, local smelting industries and assesses operative conditions of gas emissions management during 2010. There were analyzed 25 industries over 30. The sample was representative of five productive processes: aluminum (Al), aluminum/iron (Al Fe), aluminum/bronze (Al Cu+Sn), aluminum/iron/bronze (Al Fe Cu+Sn), and iron (Fe). The variables analyzed were: primary fusion mater, oven used and industry size. To obtain production data we applied structured interviews, and for industry sizes we used surveys. It was possible to describe the productive prospect of the sector at a local level: for most industries the destination of their production is automotive sector. Taking into account the relation between the size and the type of industry, the aluminum smelting companies are small. Regarding iron industries, all three company sizes are present in the sample and exists a medium size industry that occupies between 51 and 230 employees. The operative conditions and their compliance with current legislation regarding control of gas emissions require to identify monitoring indicators for the melting stage that allow knowing precisely the resulting contaminants and their environmental effects.

  7. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    Directory of Open Access Journals (Sweden)

    Lijie Guo

    2018-01-01

    Full Text Available This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS on cemented tailing backfill (CTB that contains lead-zinc smelting slag. CTB and cemented paste (CP containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis and thermal gravity analysis were performed on the studied CP samples, whereas the electrical conductivity of CTB was monitored. The results reveal that SS has a significant positive effect on cementitious activity of binder mixed by cement and lead-zinc smelting slag. This activation leads to the acceleration of binder hydration process, the formation of more cement hydration products in the CTBs, and the refinement of their pore structure, which is favorable for the strength development of CTB.

  8. Diet and gut morphology of male mallards during winter in North Dakota

    Science.gov (United States)

    Olsen, R.E.; Cox, R.R.; Afton, A.D.; Ankney, C.D.

    2011-01-01

    A free-ranging Mallard (Anas platyrhynchos) population was investigated during winter (December-January 1996-1999) below the Garrison Dam, North Dakota, USA, to relate diet to gut morphology variation in males. Four explanatory variables (fish consumption, male age, winter, and body size) were evaluated as to whether they influenced five response variables associated with gut characteristics of Mallards. Response variables were lower gastro-intestinal tract mass (LGIT), dry liver mass, dry gizzard mass, small intestine length, and ceca length. Diets of Mallards were comprised primarily of Rainbow Smelt (Osmerus mordax) and concomitantly variation in gizzard mass was small. LGIT mass of juveniles was larger than that of adults, greater for those that consumed fish, and greater during the coldest and snowiest winter. Liver mass and small intestine length of Mallards that consumed fish were greater than those that did not. Mallards may maintain lengthy intestines to increase digestive efficiency. Gut size variation was not entirely attributable to dietary composition but also influenced by body size and environmental conditions such that over-winter survival is maximized.

  9. Reevaluation of a walleye (Sander vitreus) bioenergetics model

    Science.gov (United States)

    Madenjian, Charles P.; Wang, Chunfang

    2013-01-01

    Walleye (Sander vitreus) is an important sport fish throughout much of North America, and walleye populations support valuable commercial fisheries in certain lakes as well. Using a corrected algorithm for balancing the energy budget, we reevaluated the performance of the Wisconsin bioenergetics model for walleye in the laboratory. Walleyes were fed rainbow smelt (Osmerus mordax) in four laboratory tanks each day during a 126-day experiment. Feeding rates ranged from 1.4 to 1.7 % of walleye body weight per day. Based on a statistical comparison of bioenergetics model predictions of monthly consumption with observed monthly consumption, we concluded that the bioenergetics model estimated food consumption by walleye without any significant bias. Similarly, based on a statistical comparison of bioenergetics model predictions of weight at the end of the monthly test period with observed weight, we concluded that the bioenergetics model predicted walleye growth without any detectable bias. In addition, the bioenergetics model predictions of cumulative consumption over the 126-day experiment differed fromobserved cumulative consumption by less than 10 %. Although additional laboratory and field testing will be needed to fully evaluate model performance, based on our laboratory results, the Wisconsin bioenergetics model for walleye appears to be providing unbiased predictions of food consumption.

  10. Angler-caught piscivore diets reflect fish community changes in Lake Huron

    Science.gov (United States)

    Roseman, Edward F.; Schaeffer, Jeff; Bright, Ethan; Fielder, David G.

    2014-01-01

    Examination of angler-caught piscivore stomachs revealed that Lake Trout Salvelinus namaycush, Chinook Salmon Oncorhynchus tshawytscha, and Walleyes Sander vitreus altered theirdiets in response to unprecedented declines in Lake Huron's main-basin prey fish community.Diets varied by predator species, season, and location but were nearly always dominated numerically by some combination of Alewife Alosa pseudoharengus, Rainbow Smelt Osmerus mordax, Emerald Shiner Notropis atherinoides, Round Goby Neogobius melanostomus, or terrestrial insects. Rainbow Trout Oncorhynchus mykiss (steelhead), Coho Salmon Oncorhynchus kisutch, and Atlantic Salmon Salmo salar had varied diets that reflected higher contributions of insects. Compared with an earlier (1983–1986) examination of angler-caught predator fishes from Lake Huron, the contemporary results showed an increase in consumption of nontraditional prey (including conspecifics), use of smaller prey, and an increase in insects in the diet, suggesting that piscivores were faced with chronic prey limitation during this study. The management of all piscivores in Lake Huron will likely require consideration of the pervasive effects of changes in food webs, especially if prey fish remain at low levels.

  11. Study on Apparent Kinetic Prediction Model of the Smelting Reduction Based on the Time-Series

    Directory of Open Access Journals (Sweden)

    Guo-feng Fan

    2012-01-01

    Full Text Available A series of direct smelting reduction experiment has been carried out with high phosphorous iron ore of the different bases by thermogravimetric analyzer. The derivative thermogravimetric (DTG data have been obtained from the experiments. One-step forward local weighted linear (LWL method , one of the most suitable ways of predicting chaotic time-series methods which focus on the errors, is used to predict DTG. In the meanwhile, empirical mode decomposition-autoregressive (EMD-AR, a data mining technique in signal processing, is also used to predict DTG. The results show that (1 EMD-AR(4 is the most appropriate and its error is smaller than the former; (2 root mean square error (RMSE has decreased about two-thirds; (3 standardized root mean square error (NMSE has decreased in an order of magnitude. Finally in this paper, EMD-AR method has been improved by golden section weighting; its error would be smaller than before. Therefore, the improved EMD-AR model is a promising alternative for apparent reaction rate (DTG. The analytical results have been an important reference in the field of industrial control.

  12. Antimony smelting process generating solid wastes and dust: characterization and leaching behaviors.

    Science.gov (United States)

    Guo, Xuejun; Wang, Kunpeng; He, Mengchang; Liu, Ziwei; Yang, Hailin; Li, Sisi

    2014-07-01

    A large amount of solid waste has been produced by the antimony smelting process in the "World Capital of Antimony", Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag, arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 10⁴ and 3.16×10⁵ mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste. Copyright © 2014. Published by Elsevier B.V.

  13. Questions about the reliability of recovery boilers of steel smelting units

    Energy Technology Data Exchange (ETDEWEB)

    Sazykin, Yu K; Mukhametzyanov, N K

    1979-01-01

    Because the main reason for failure of recovery boilers is contamination of the heating surfaces, the operational conditions of individual elements of boiler units, equipped with vibrational and pulsed cleaning are analyzed and the reliability of the cleaning systems in use today is evaluated. The recovery boilers from open hearth furnaces and two bath steel smelting units from the Magnitogorsk Metallurgic Combine were selected as the subjects of the study. It is established that the boiler heating surface cleaning system has a quite large number of failures. The vibrational cleaning readiness factor is rated at 0.9323 and that of the pulsed cleaning system, 0.9698. For the KU-100 recovery boilers with a mean productivity of 18-20 t/h, the losses caused by failures during operation with vibration and pulsed cleaning were 3,200 and 1,700 rubles per year, respectively. With reconstruction of the boilers, which is associated with an increase in their reliability, the vibration cleaning of the heating surface was replaced by pulsed cleaning.

  14. Nonlinear system identification of the reduction nickel oxide smelting process in electric arc furnace

    Science.gov (United States)

    Gubin, V.; Firsov, A.

    2018-03-01

    As the title implies the article describes the nonlinear system identification of the reduction smelting process of nickel oxide in electric arc furnaces. It is suggested that for operational control ratio of components of the charge must be solved the problem of determining the qualitative composition of the melt in real time. The use of 0th harmonic of phase voltage AC furnace as an indirect measure of the melt composition is proposed. Brief description of the mechanism of occurrence and nature of the non-zero 0th harmonic of the AC voltage of the arc is given. It is shown that value of 0th harmonic of the arc voltage is not function of electrical parameters but depends of the material composition of the melt. Processed industrial data are given. Hammerstein-Wiener model is used for description of the dependence of 0th harmonic of the furnace voltage from the technical parameters of melting furnace: the melt composition and current. Recommendations are given about the practical use of the model.

  15. Arsenic exposure levels in relation to different working departments in a copper mining and smelting plant

    Science.gov (United States)

    Sun, Qingshan; Song, Yingli; Liu, Shengnan; Wang, Fei; Zhang, Lin; Xi, Shuhua; Sun, Guifan

    2015-10-01

    The investigation was carried out to evaluate arsenic exposure and the urine metabolite profiles of workers with different working departments, including administration (Group1), copper ore mining (Group2), copper ore grinding (Group3), electrolytic procession (Group4) and copper smelting (Group5) in a Copper mining and processing plant in China. Information about characteristics of each subject was obtained by questionnaire and inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) in urine were determined. The highest urinary levels of iAs, MMA and DMA all were found in the Group 5. Group 4 workers had a higher iAs% and a lower PMI compared to Group 3. The urinary total As (TAs) levels of 54.7% subjects exceeded 50 μg/g Cr, and the highest percentage (93.3%) was found in Group 5, smelters. The results of the present study indicate that workers in copper production plant indeed exposed to As, especially for smelters and workers of electrolytic process.

  16. Influence of alumina on mineralogy and environmental properties of zinc-copper smelting slags

    Science.gov (United States)

    Mostaghel, Sina; Samuelsson, Caisa; Björkman, Bo

    2013-03-01

    An iron-silicate slag, from a zinc-copper smelting process, and mixtures of this slag with 5wt%, 10wt%, and 15wt% alumina addition were re-melted, semi-rapidly solidified, and characterized using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction. The FactSage™6.2 thermodynamic package was applied to compare the stable phases at equilibrium conditions with experimental characterization. A standard European leaching test was also carried out for all samples to investigate the changes in leaching behaviour because of the addition of alumina. Results show that the commonly reported phases for slags from copper and zinc production processes (olivine, pyroxene, and spinel) are the major constituents of the current samples. A correlation can be seen between mineralogical characteristics and leaching behaviours. The sample with 10wt% alumina addition, which contains high amounts of spinels and lower amounts of the other soluble phases, shows the lowest leachabilities for most of the elements.

  17. Different Heavy Metal Accumulation Strategies of Epilithic Lichens Colonising Artificial Post-Smelting Wastes.

    Science.gov (United States)

    Rola, Kaja; Osyczka, Piotr; Kafel, Alina

    2016-02-01

    Lichens appear to be essential and effective colonisers of bare substrates including the extremely contaminated wastes of slag dumps. This study examines the metal accumulation capacity of epilithic lichens growing directly on the surface of artificial slag sinters. Four species representing different growth forms, i.e., crustose Candelariella aurella, Lecanora muralis, and Lecidea fuscoatra and fruticose Stereocaulon nanodes, were selected to evaluate the relationships between zinc, lead, cadmium, and nickel contents in their thalli and host substrates. Bioaccumulation factors of examined crustose lichens showed their propensity to hyperaccumulate heavy metals. Contrarily, concentrations of metals in fruticose thalli of S. nanodes were, as a rule, lower than in the corresponding substrates. This indicates that the growth form of thalli and degree of thallus adhesion to the substrate has a significant impact on metal concentrations in lichens colonising post-smelting wastes. Nonlinear regression models described by power functions show that at greater levels of Pb concentration in the substrate, the ability of C. aurella, L. muralis and L. fuscoatra to accumulate the metal experiences a relative decrease, whereas hyperbolic function describes a similar trend in relation to Ni content in S. nanodes. This phenomenon may be an important attribute of lichens that facilitates their colonisation of the surface of slag wastes.

  18. Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

    Science.gov (United States)

    Hillman, Aubrey L; Abbott, Mark B; Yu, JunQing; Bain, Daniel J; Chiou-Peng, TzeHuey

    2015-03-17

    Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

  19. Lead toxicosis in tundra swans near a mining and smelting complex in northern Idaho

    Science.gov (United States)

    Blus, L.J.; Henny, C.J.; Hoffman, D.J.; Grove, R.A.

    1991-01-01

    Die-offs of waterfowl have occurred in the Coeur d`Alene River system in northern Idaho since at least the early 1900`s. We investigated causes of mortality and lead and cadmium contamination of 46 tundra swans (Cygnus columbianus) from 1987 to 1989; an additional 22 swans found dead in 1990 were not examined. We necropsied 43 of the 46 birds found from 1987 to 1989; 38 of these were from the Coeur d`Alene River system, which has been contaminated with mining and smelting wastes for a century, and the other 5 were from a nearby, relatively uncontaminated area. Of the 36 livers of swans from the contaminated area that were analyzed, 32 contained lethal levels of lead (6 to 40 micrograms/g, wet weight) and all birds exhibited several symptoms of lead poisoning, notably enlarged gall bladders containing viscous, darkgreen bile. Only 13% of the lead-poisoned birds (10% when data were included from other studies of swans in the area) contained shot, compared to 95% of lead-poisoning swans in studies outside northern Idaho. Lead concentrations in blood samples from 16 apparently healthy swans (0.5 to 2.3 micrograms/g, and 4 leadpoisoned birds found moribund (1.3 to 9.6 micrograms/g) indicating that tundra swans accumulated high levels of lead from ingestion of sediment that contained up to 8,700 micrograms/g of lead and plants that contained up to 400 micrograms/g. The swans spend only a few weeks in the area staging during the spring migration. The five tundra swans from the uncontaminated area had low levels of lead and essentially no symptoms of lead poisoning.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Behavior of an indigenously fabricated transferred arc plasma furnace for smelting studies

    Science.gov (United States)

    A, K. MANDAL; R, K. DISHWAR; O, P. SINHA

    2018-03-01

    The utilization of industrial solid waste for metal recovery requires high-temperature tools due to the presence of silica and alumina, which is reducible at high temperature. In a plasma arc furnace, transferred arc plasma furnace (TAP) can meet all requirements, but the disadvantage of this technology is the high cost. For performing experiments in the laboratory, the TAP was fabricated indigenously in a laboratory based on the different inputs provided in the literature for the furnace design and fabrication. The observed parameters such as arc length, energy consumption, graphite electrode consumption, noise level as well as lining erosion were characterized for this fabricated furnace. The nitrogen plasma increased by around 200 K (200 °C) melt temperature and noise levels decreased by ∼10 dB compared to a normal arc. Hydrogen plasma offered 100 K (100 °C) higher melt temperature with ∼5 dB higher sound level than nitrogen plasma. Nitrogen plasma arc melting showed lower electrode and energy consumption than normal arc melting, whereas hydrogen plasma showed lower energy consumption and higher electrode consumption in comparison to nitrogen plasma. The higher plasma arc temperature resulted in a shorter meltdown time than normal arc with smoother arcing. Hydrogen plasma permitted more heats, reduced meltdown time, and lower energy consumption, but with increased graphite consumption and crucible wear. The present study showed that the fabricated arc plasma is better than the normal arc furnace with respect to temperature generation, energy consumption, and environmental friendliness. Therefore, it could be used effectively for smelting-reduction studies.

  1. Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

    Science.gov (United States)

    Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

    2012-02-01

    Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

  2. Can Silicon-Smelting Contribute to the Low O/Si Ratio on the Surface of Mercury?

    Science.gov (United States)

    McCubbin, F. M.; Vander Kaaden, K. E.; Hogancamp, J.; Archer, P. D., Jr.; Boyce, J. W.

    2018-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft collected data that provided important insights into the structure, chemical makeup, and compositional diversity of Mercury. Among the many discoveries about Mercury made by MESSENGER, several surprising compositional characteristics of the surface were observed. These discoveries include elevated sulfur abundances (up to 4 wt.%), elevated abundances of graphitic carbon (0-4.1 wt.% across the surface with an additional 1-3 wt.% graphite above the global average in low reflectance materials), low iron abundances (less than 2 wt.%), and low oxygen abundances (O/Si weight ratio of 1.20+/-0.1). These exotic characteristics likely have important implications for the thermochemical evolution of Mercury and point to a planet that formed under highly reducing conditions. In the present study, we focus specifically on the low O/Si ratio of Mercury, which is anomalous compared to all other planetary materials. A recent study that considered the geochemical implications of the low O/Si ratio reported that 12-20% of the surface materials on Mercury are composed of Si-rich, Si-Fe alloys. They further postulated that the origin of the metal is best explained by a combination of space weathering and graphite-induced smelting that was facilitated by interaction of graphite with boninitic and komatiitic parental liquids. The goal of the present study is to assess the plausibility of smelting on Mercury through experiments run at the conditions that McCubbin et al. indicated would be favorable for Si-smelting.

  3. A Water Model Study on Mixing Behavior of the Two-Layered Bath in Bottom Blown Copper Smelting Furnace

    Science.gov (United States)

    Shui, Lang; Cui, Zhixiang; Ma, Xiaodong; Jiang, Xu; Chen, Mao; Xiang, Yong; Zhao, Baojun

    2018-05-01

    The bottom-blown copper smelting furnace is a novel copper smelter developed in recent years. Many advantages of this furnace have been found, related to bath mixing behavior under its specific gas injection scheme. This study aims to use an oil-water double-phased laboratory-scale model to investigate the impact of industry-adjustable variables on bath mixing time, including lower layer thickness, gas flow rate, upper layer thickness and upper layer viscosity. Based on experimental results, an overall empirical relationship of mixing time in terms of these variables has been correlated, which provides the methodology for industry to optimize mass transfer in the furnace.

  4. Effect of Copper and Iron Ions on the Sulphidizing Flotation of Copper Oxide in Copper Smelting Slag

    OpenAIRE

    Qing-qing Pan; Hui-qing Peng

    2018-01-01

    The treatment of smelting slag has attracted much attention nowadays. This study investigates the influence of Na2S, CuSO4, and FeCl3 on sulphidizing flotation of copper oxide. The results show that a proper Cu2+ concentration can increase the sulphidizing effect of copper oxide, while Fe3+ inhibits the sulphidizing effect. Further analysis shows that Cu2+ ions can reduce the surface potential, increase the S2− adsorption, then generate more polysulfide, and therefore promote the sulphidizing...

  5. Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

    2018-03-01

    Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

  6. Comparative growth models of big-scale sand smelt (Atherina boyeri Risso, 1810 sampled from Hirfanll Dam Lake, Klrsehir, Ankara, Turkey

    Directory of Open Access Journals (Sweden)

    S. Benzer

    2017-06-01

    Full Text Available In this current publication the growth characteristics of big-scale sand smelt data were compared for population dynamics within artificial neural networks and length-weight relationships models. This study aims to describe the optimal decision of the growth model of big-scale sand smelt by artificial neural networks and length-weight relationships models at Hirfanll Dam Lake, Klrsehir, Turkey. There were a total of 1449 samples collected from Hirfanll Dam Lake between May 2015 and May 2016. Both model results were compared with each other and the results were also evaluated with MAPE (mean absolute percentage error, MSE (mean squared error and r2 (coefficient correlation data as a performance criterion. The results of the current study show that artificial neural networks is a superior estimation tool compared to length-weight relationships models of big-scale sand smelt in Hirfanll Dam Lake.

  7. Coupling age-structured stock assessment and fish bioenergetics models: a system of time-varying models for quantifying piscivory patterns during the rapid trophic shift in the main basin of Lake Huron

    Science.gov (United States)

    He, Ji X.; Bence, James R.; Madenjian, Charles P.; Pothoven, Steven A.; Dobiesz, Norine E.; Fielder, David G.; Johnson, James E.; Ebener, Mark P.; Cottrill, Adam R.; Mohr, Lloyd C.; Koproski, Scott R.

    2015-01-01

    We quantified piscivory patterns in the main basin of Lake Huron during 1984–2010 and found that the biomass transfer from prey fish to piscivores remained consistently high despite the rapid major trophic shift in the food webs. We coupled age-structured stock assessment models and fish bioenergetics models for lake trout (Salvelinus namaycush), Chinook salmon (Oncorhynchus tshawytscha), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis). The model system also included time-varying parameters or variables of growth, length–mass relations, maturity schedules, energy density, and diets. These time-varying models reflected the dynamic connections that a fish cohort responded to year-to-year ecosystem changes at different ages and body sizes. We found that the ratio of annual predation by lake trout, Chinook salmon, and walleye combined with the biomass indices of age-1 and older alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) increased more than tenfold during 1987–2010, and such increases in predation pressure were structured by relatively stable biomass of the three piscivores and stepwise declines in the biomass of alewives and rainbow smelt. The piscivore stability was supported by the use of alternative energy pathways and changes in relative composition of the three piscivores. In addition, lake whitefish became a new piscivore by feeding on round goby (Neogobius melanostomus). Their total fish consumption rivaled that of the other piscivores combined, although fish were still a modest proportion of their diet. Overall, the use of alternative energy pathways by piscivores allowed the increases in predation pressure on dominant diet species.

  8. Mercury levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes.

    Science.gov (United States)

    Blukacz-Richards, E Agnes; Visha, Ariola; Graham, Matthew L; McGoldrick, Daryl L; de Solla, Shane R; Moore, David J; Arhonditsis, George B

    2017-04-01

    Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow smelt (Osmerus mordax). Trends were quantified with dynamic linear models, which provided time-variant rates of change of mercury concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, mercury levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in Lake Erie and two sites in Lake Ontario. Similar trend reversals in the 2000s were observed for lake trout in Lake Superior and at a single station in Lake Ontario. Mercury levels in lake trout continued to slowly decline at all of the remaining stations, except for Lake Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and rainbow smelt in Lake Superior and Lake Ontario, but also pinpoints the likelihood of a trophic decoupling in Lake Huron and Lake Erie. Continued monitoring of mercury levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  9. Comparison of thiaminase activity in fish using the radiometric and 4-nitrothiophenol colorimetric methods

    Science.gov (United States)

    Honeyfield, D.C.; Hanes, J.W.; Brown, L.; Kraft, C.E.; Begley, T.P.

    2010-01-01

    Thiaminase induced thiamine deficiency occurs in fish, humans, livestock and wild animals. A non-radioactive thiaminase assay was described in 2007, but a direct comparison with the radioactive 14C-thiamine method which has been in use for more than 30years has not been reported. The objective was to measure thiaminase activity in forage fish (alewife Alosa pseudoharengus, rainbow smelt Osmerus mordax, and slimy sculpin Cottus cognatus) consumed by predators that manifest thiamine deficiency using both methods. Modifications were made to the colorimetric assay to improve repeatability. Modification included a change in assay pH, enhanced sample clean-up, constant assay temperature (37??C), increase in the concentration of 4-nitrothiophenol (4NTP) and use of a spectrophotometer fitted with a 0.2cm cell. A strong relationship between the two assays was found for 51 alewife (R2=0.85), 36 smelt (R2=0.87) and 20 sculpin (R2=0.82). Thiaminase activity in the colorimetric assay was about 1000 times higher than activity measured by the radioactive method. Application of the assay to fish species from which no thiaminase activity has previously been reported resulted in no 4NTP thiaminase activity being found in bloater Coregonus hoyi, lake trout Salvelinus namaycusch, steelhead trout Oncorhynchus mykiss or Chinook salmon Oncorhynchus tshawytscha. In species previously reported to contain thiaminase, 4NTP thiaminase activity was measured in bacteria Paenibacillus thiaminolyticus, gizzard shad Dorosoma cepedianum, bracken fern Pteridium aquilinum, quagga mussel Dreissena bugensis and zebra mussels D. polymorpha. ?? 2010.

  10. Dynamic variation of histone H3 trimethyl Lys4 (H3K4me3) and heterochromatin protein 1 (HP1) with employment length in nickel smelting workers.

    Science.gov (United States)

    Zhao, Yanhong; Cheng, Ning; Dai, Min; Pu, Hongquan; Zheng, Tongzhang; Li, Haiyan; He, Jie; Bai, Yana

    2017-07-01

    To investigate the dynamic variation in H3K4me3 and HP1 with employment length in nickel smelting workers. Blood samples were collected from 140 nickel smelting workers and 140 age-matched office workers to test for H3K4me3, and HP1 levels. H3K4me3 was statistically significantly different (p exposure to nickel can induce oxidative damage, and increase H3K4me3 expression and inhibit HP1 expression.

  11. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    International Nuclear Information System (INIS)

    Silva, Cátia S.E.; Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana; Oliveira, Ana P.; Gonçalves, Emanuel J.; Faria, Ana M.

    2016-01-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO_2. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO_2, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO_2 on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO_2 levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U_c_r_i_t), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO_2 leads to higher energetic costs and morphometric changes, with larger larvae in high pCO_2 treatment and smaller larvae in medium pCO_2 treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO_2 treatment may indicate that at higher pCO_2 levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO_2 levels on organisms. - Highlights: • Exposure to high pCO_2

  12. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cátia S.E. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana [MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Oliveira, Ana P. [IPMA — Instituto Português do Mar e da Atmosfera, Algés (Portugal); Gonçalves, Emanuel J. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); Faria, Ana M., E-mail: afaria@ispa.pt [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal)

    2016-09-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO{sub 2}. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO{sub 2}, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO{sub 2} on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO{sub 2} levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U{sub crit}), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO{sub 2} leads to higher energetic costs and morphometric changes, with larger larvae in high pCO{sub 2} treatment and smaller larvae in medium pCO{sub 2} treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO{sub 2} treatment may indicate that at higher pCO{sub 2} levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO{sub 2} levels on

  13. Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

    International Nuclear Information System (INIS)

    Bi Xiangyang; Feng Xinbin; Yang Yuangen; Li Xiangdong; Shin, Grace P.Y.; Li Feili; Qiu Guangle; Li Guanghui; Liu Taoze; Fu Zhiyou

    2009-01-01

    Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake. - The sources and pathways of Pb and Cd accumulated in maize were assessed using Pb isotopes and Pb/Cd ratios

  14. Bioleaching mechanism of Zn, Pb, In, Ag, Cd and As from Pb/Zn smelting slag by autotrophic bacteria.

    Science.gov (United States)

    Wang, Jia; Huang, Qifei; Li, Ting; Xin, Baoping; Chen, Shi; Guo, Xingming; Liu, Changhao; Li, Yuping

    2015-08-15

    A few studies have focused on release of valuable/toxic metals from Pb/Zn smelting slag by heterotrophic bioleaching using expensive yeast extract as an energy source. The high leaching cost greatly limits the practical potential of the method. In this work, autotrophic bioleaching using cheap sulfur or/and pyrite as energy matter was firstly applied to tackle the smelting slag and the bioleaching mechanisms were explained. The results indicated autotrophic bioleaching can solubilize valuable/toxic metals from slag, yielding maximum extraction efficiencies of 90% for Zn, 86% for Cd and 71% for In, although the extraction efficiencies of Pb, As and Ag were poor. The bioleaching performance of Zn, Cd and Pb was independent of leaching system, and leaching mechanism was acid dissolution. A maximum efficiency of 25% for As was achieved by acid dissolution in sulfursulfur oxidizing bacteria (S-SOB), but the formation of FeAsO4 reduced extraction efficiency in mixed energy source - mixed culture (MS-MC). Combined works of acid dissolution and Fe(3+) oxidation in MS-MC was responsible for the highest extraction efficiency of 71% for In. Ag was present in the slag as refractory AgPb4(AsO4)3 and AgFe2S3, so extraction did not occur. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

    Energy Technology Data Exchange (ETDEWEB)

    Bi Xiangyang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Key Laboratory of Biogeology and Environmental Geology, Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: fengxinbin@vip.skleg.cn; Yang Yuangen [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Li Xiangdong; Shin, Grace P.Y. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Li Feili [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Qiu Guangle; Li Guanghui; Liu Taoze; Fu Zhiyou [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)

    2009-03-15

    Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake. - The sources and pathways of Pb and Cd accumulated in maize were assessed using Pb isotopes and Pb/Cd ratios.

  16. High-Temperature Oxidation and Smelt Deposit Corrosion of Ni-Cr-Ti Arc-Sprayed Coatings

    Science.gov (United States)

    Matthews, S.; Schweizer, M.

    2013-08-01

    High Cr content Ni-Cr-Ti arc-sprayed coatings have been extensively applied to mitigate corrosion in black liquor recovery boilers in the pulp and paper industry. In a previous article, the effects of key spray parameters on the coating's microstructure and its composition were investigated. Three coating microstructures were selected from that previous study to produce a dense, oxidized coating (coating A), a porous, low oxide content coating (coating B), and an optimized coating (coating C) for corrosion testing. Isothermal oxidation trials were performed in air at 550 and 900 °C for 30 days. Additional trials were performed under industrial smelt deposits at 400 and 800 °C for 30 days. The effect of the variation in coating microstructure on the oxidation and smelt's corrosion response was investigated through the characterization of the surface corrosion products, and the internal coating microstructural developments with time at high temperature. The effect of long-term, high-temperature exposure on the interaction between the coating and substrate was characterized, and the mechanism of interdiffusion was discussed.

  17. Recirculation effect of Chilean copper smelting dust with high impurities contents on the impurity distributions during smelting process; Efecto de la recirculacion de polvo de fundicion de cobre de Chile con altos contenidos de impurezas en la distribucion de impurezas durante el proceso de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Montenegro, V.; Sano, H.; Fujisawa, T.

    2010-07-01

    Usually, dust generated during the copper smelting process by the Teniente Converter and the Flash Smelting Furnaces in Chile, contains high concentrations of copper, zinc, arsenic, antimony and other metals. In general, the dust is recirculated to the smelting process or it is directed to hydrometallurgical process for recovery and stabilization. However, in recent years the generation of dust has increased because of the degradation of the quality of the concentrate. In addition, the environmental regulations have become stricter. It is therefore desirable to understand the behavior of those elements, when the smelting process operates with recirculation of dust. In this study, the effect of dust recirculation to smelting process on the distribution among the matte, slag and gas phases was evaluated, as a function of matte grade, amount of recirculated dust, oxygen enrichment and temperature. It was found that the concentration in the matte of the impurities such as arsenic, antimony and bismuth, increased slightly with recirculation of dust. On the other hand, the concentration of lead and zinc depend of the direct recirculation of dust to the process. Additionally, it was found that high concentrations of arsenic and antimony in the dust may lead to the formation and precipitation of copper arsenates and other metals (speiss), which may generates important operational problems. (Author) 15 refs.

  18. Size-resolved dust and aerosol contaminants associated with copper and lead smelting emissions: Implications for emission management and human health

    Energy Technology Data Exchange (ETDEWEB)

    Csavina, Janae [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Taylor, Mark P. [Environmental Science, Faculty of Science, Macquarie University, North Ryde, Sydney, NSW 2109 (Australia); Félix, Omar [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Rine, Kyle P. [Department of Atmospheric Sciences, The University of Arizona, Tucson, AZ 85721 (United States); Eduardo Sáez, A., E-mail: esaez@email.arizona.edu [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Betterton, Eric A., E-mail: betterton@atmo.arizona.edu [Department of Atmospheric Sciences, The University of Arizona, Tucson, AZ 85721 (United States)

    2014-09-15

    Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (< 1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (< 1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emission management and practices that minimize health risks associated with metal extraction and processing can be developed. - Highlights: • Lead and copper smelting produce significant atmospheric concentrations of lead and arsenic. • Atmospheric lead and arsenic concentrations depend on particle size. • Lead isotopic analysis can be used to assess source of atmospheric contamination from smelters.

  19. Thermodynamics Calculation and Experimental Study on Separation of Bismuth from a Bismuth Glance Concentrate Through a Low-Temperature Molten Salt Smelting Process

    Science.gov (United States)

    Yang, Jian-Guang; He, De-Wen; Tang, Chao-Bo; Chen, Yong-Ming; Sun, Ya-Hui; Tang, Mo-Tang

    2011-08-01

    The main purpose of this study is to characterize and separate bismuth from a bismuth glance concentrate through a low-temperature, sulfur-fixing smelting process. This article reports on a study conducted on the optimization of process parameters, such as Na2CO3 and zinc oxide wt pct in charging, smelting temperature, smelting duration on the bismuth yield, resultant crude bismuth grade, and sulfur-fixing rate. A maximum bismuth recovery of 97.31 pct, crude bismuth grade of 96.93 pct, and 98.23 pct sulfur-fixing rate are obtained when a charge (containing 63.50 wt pct of Na2CO3 and 22.50 wt pct of bismuth glance, as well as 5 pct in excess of the stoichiometric requirement of zinc oxide dosage) is smelted at 1000 K (727 °C) for 150 minutes. This smelting operation is free from atmospheric pollution because zinc oxide is used as the sulfur-fixing agent, which can capture sulfur from bismuth sulfide and form the more thermodynamic-stable compound, zinc sulfide. The solid residue is subjected to a mineral dressing operation to obtain suspension, which is filtered to produce a cake, representing the solid particles of zinc sulfide. Based on the results of the chemical content analysis of the as-resultant zinc sulfide, more than 93 pct zinc sulfide can be recovered, and the recovered zinc sulfide grade can reach 60.20 pct. This material can be sold as zinc sulfide concentrate or roasted to be regenerated as zinc oxide.

  20. A Covered Cod-End and Tow-Path Evaluation of Midwater Trawl Gear Efficiency for Catching Delta Smelt (Hypomesus transpacificus

    Directory of Open Access Journals (Sweden)

    Lara Mitchell

    2017-12-01

    Full Text Available https://doi.org/10.15447/sfews.2017v15iss4art3For nearly 50 years, the California Department of Fish and Wildlife has used a midwater trawl to intensively monitor fish populations in the San Francisco Estuary during the fall, sampling over 100 locations each month. The data collected have been useful for calculating indices of fish abundance and for detecting and documenting the decline of the endangered fish species delta smelt (Hypomesus transpacificus. However, efforts to calculate estimates of absolute abundance have been hampered by the lack of information on gear efficiency, in particular questions about contact selectivity and the effect of tow method on catches. To answer these questions we conducted a study that used a covered cod end on a net towed either near the surface, referred to as a surface tow, or throughout the water column, referred to as an oblique tow. A contact selectivity model was fit to estimate the probability that a delta smelt that has come into contact with the net is retained in the cod end of the net conditional on its body length. Full retention of delta smelt was found to occur around 60 mm fork length. Delta smelt catch densities for the surface tows were an order of magnitude greater than densities in the oblique tows, suggesting a surface orientation at the sub-adult life stage. These results represent an important step in being able to calculate absolute abundance estimates of the delta smelt population size using decades’ worth of monitoring data.

  1. Rapid Microwave Digestion Procedures for the Elemental Analysis of Alloy and Slag Samples of Smelted Ocean Bed Polymetallic Nodules

    Directory of Open Access Journals (Sweden)

    Kumari Smita

    2013-01-01

    Full Text Available The use of microwave digester for digestion of alloy and slag samples of smelted ocean bed polymetallic nodules has permitted the complete digestion of samples, thereby replacing the tedious classical methods of digestion of samples. The digestion procedure includes two acid-closed digestions of samples in a microwave oven. Owing to the hazardous nature of perchloric acid, it was not used in developed digestion procedure. Digested sample solutions were analyzed for concentrations of various radicals and the effectiveness of the developed digestion methodology was tested using certified reference materials. It was found that the developed method is giving results comparable with that obtained from conventionally digested samples. In this digestion procedure, time required for digestion of samples was reduced to about 1 hour only from 8-9 hours of conventional digestion.

  2. Study of the ancient iron-smelting sites at Pantaki, Tsauni and Samaru-west, Nigeria, using neutron activation analysis

    International Nuclear Information System (INIS)

    Oladipupo, M.D.; OIadipo, M.O.A.; Mallam, S.P.; Akpa, T.C.

    2010-01-01

    Neutron activation analysis was used to obtain concentrations of some elements in samples of potsherds and furnaces obtained from Pantaki, Tsauni and Samaru-west ancient iron-smelting sites. Using WARD method, cluster analysis of the elements was carried out to establish the relationship between the archaeological samples in term of similarity in elemental concentrations. It was found that there is some level of similarity among the potsherd samples from the three sites. Also, most of furnace samples display some similarity. It was established that there was cultural linkage between the iron-smelters at the different sites. The similarity between the samples lead to a conclusion that pot makers and furnace makers could have existed, who obtained clays from common sources, made and sold the products to users in different communities.

  3. Preparation of Cementitious Material Using Smelting Slag and Tailings and the Solidification and Leaching of Pb2+

    Directory of Open Access Journals (Sweden)

    Dan Zhang

    2015-01-01

    Full Text Available The composite cementitious materials were prepared with lead-zinc tailings, lead-zinc smelting slag, and cement clinker. The effect of material ratio on the mechanical properties, the phase analysis, and microstructures were investigated. The effect of the pH and stripping time on the leaching amount of lead ion was discussed. The results show that the additive amount of the tailings should be minimized for the cementitious materials meeting the strength requirements, controlled within 10%. The leaching amount of cementitious materials remains low in a larger range of pH, which can effectively reduce the leaching of heavy metal lead. The leaching kinetics of lead ions in the three kinds of samples could be better described by the pseudo-second-model.

  4. Effect of Copper and Iron Ions on the Sulphidizing Flotation of Copper Oxide in Copper Smelting Slag

    Directory of Open Access Journals (Sweden)

    Qing-qing Pan

    2018-01-01

    Full Text Available The treatment of smelting slag has attracted much attention nowadays. This study investigates the influence of Na2S, CuSO4, and FeCl3 on sulphidizing flotation of copper oxide. The results show that a proper Cu2+ concentration can increase the sulphidizing effect of copper oxide, while Fe3+ inhibits the sulphidizing effect. Further analysis shows that Cu2+ ions can reduce the surface potential, increase the S2− adsorption, then generate more polysulfide, and therefore promote the sulphidizing flotation. However, Fe3+ ions would increase the surface potential, reduce the S2− adsorption, generate more sulfur element, and therefore inhibit the sulphidizing flotation.

  5. Bacterial community structure and diversity responses to the direct revegetation of an artisanal zinc smelting slag after 5 years.

    Science.gov (United States)

    Luo, Youfa; Wu, Yonggui; Wang, Hu; Xing, Rongrong; Zheng, Zhilin; Qiu, Jing; Yang, Lian

    2018-05-01

    This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag. Additionally, revegetation increased the relative abundance of plant growth-promoting rhizobacteria such as Flavobacterium, Streptomyces, and Arthrobacter as well as symbiotic N 2 fixers such as Bradyrhizobium. Three dominant native plant species (Arundo donax, Broussonetia papyrifera, and Robinia pseudoacacia) greatly increased the quality of the rhizosphere slags. Canonical correspondence analysis showed that the differences in bacterial community structure between the bulk and rhizosphere slags were explained by slag properties, i.e., pH, available copper (Cu) and lead (Pb), moisture, available nitrogen (N), phosphorus (P), and potassium (K), and organic matter (OM); however, available Zn and cadmium (Cd) contents were the slag parameters that best explained the differences between the rhizosphere communities of the eight plant species. The results suggested that revegetation plays an important role in enhancing bacterial community abundance and diversity in rhizosphere slags and that revegetation may also regulate microbiological properties and diversity mainly through changes in heavy metal bioavailability and physiochemical slag characteristics.

  6. Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Wim J. Kimmerer

    2008-06-01

    Full Text Available Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha and delta smelt (Hypomesus transpacificus to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young. These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15% although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%. The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

  7. Research on the Characteristics and Mechanism of the Cumulative Release of Antimony from an Antimony Smelting Slag Stacking Area under Rainfall Leaching

    Science.gov (United States)

    Zhou, Yingying; Deng, Renjian

    2017-01-01

    We aimed to study the characteristics and the mechanism of the cumulative release of antimony at an antimony smelting slag stacking area in southern China. A series of dynamic and static leaching experiments to simulate the effects of rainfall were carried out. The results showed that the release of antimony from smelting slag increased with a decrease in the solid-liquid ratio, and the maximum accumulated release was found to be 42.13 mg Sb/kg waste and 34.26 mg Sb/kg waste with a solid/liquid ratio of 1 : 20; the maximum amount of antimony was released within 149–420 μm size fraction with 7.09 mg/L of the cumulative leaching. Also, the antimony release was the greatest and most rapid at pH 7.0 with the minimum release found at pH 4.0. With an increase in rainfall duration, the antimony release increased. The influence of variation in rainfall intensity on the release of antimony from smelting slag was small. PMID:28804669

  8. Transplantation of epiphytic bioaccumulators (Tillandsia capillaris) for high spatial resolution biomonitoring of trace elements and point sources deconvolution in a complex mining/smelting urban context

    Science.gov (United States)

    Goix, Sylvaine; Resongles, Eléonore; Point, David; Oliva, Priscia; Duprey, Jean Louis; de la Galvez, Erika; Ugarte, Lincy; Huayta, Carlos; Prunier, Jonathan; Zouiten, Cyril; Gardon, Jacques

    2013-12-01

    Monitoring atmospheric trace elements (TE) levels and tracing their source origin is essential for exposure assessment and human health studies. Epiphytic Tillandsia capillaris plants were used as bioaccumulator of TE in a complex polymetallic mining/smelting urban context (Oruro, Bolivia). Specimens collected from a pristine reference site were transplanted at a high spatial resolution (˜1 sample/km2) throughout the urban area. About twenty-seven elements were measured after a 4-month exposure, also providing new information values for reference material BCR482. Statistical power analysis for this biomonitoring mapping approach against classical aerosols surveys performed on the same site showed the better aptitude of T. Capillaris to detect geographical trend, and to deconvolute multiple contamination sources using geostatistical principal component analysis. Transplanted specimens in the vicinity of the mining and smelting areas were characterized by extreme TE accumulation (Sn > Ag > Sb > Pb > Cd > As > W > Cu > Zn). Three contamination sources were identified: mining (Ag, Pb, Sb), smelting (As, Sn) and road traffic (Zn) emissions, confirming results of previous aerosol survey.

  9. Geochemical and Pb isotopic evidence for sources and dispersal of metal contamination in stream sediments from the mining and smelting district of Pribram, Czech Republic

    International Nuclear Information System (INIS)

    Ettler, Vojtech; Mihaljevic, Martin; Sebek, Ondrej; Molek, Michael; Grygar, Tomas; Zeman, Josef

    2006-01-01

    Stream sediments from the mining and smelting district of Pribram, Czech Republic, were studied to determine the degree, sources and dispersal of metal contamination using a combination of bulk metal and mineralogical determinations, sequential extractions and Pb isotopic analyses. The highest metal concentrations were found 3-4 km downstream from the main polymetallic mining site (9800 mg Pb kg -1 , 26 039 mg Zn kg -1 , 316.4 mg Cd kg -1 , 256.9 mg Cu kg -1 ). The calculated enrichment factors (EFs) confirmed the extreme degree of contamination by Pb, Zn and Cd (EF > 40). Lead, Zn and Cd are bound mainly to Fe oxides and hydroxides. In the most contaminated samples Pb is also present as Pb carbonates and litharge (PbO). Lead isotopic analysis indicates that the predominant source of stream sediment contamination is historic Pb-Ag mining and primary Pb smelting ( 206 Pb/ 207 Pb = 1.16), while the role of secondary smelting (car battery processing) is negligible. - Pb isotopes properly complete traditional investigations of metal sources and dispersal in contaminated stream sediments

  10. Technogenic magnetic particles in soils as evidence of historical mining and smelting activity: A case of the Brynica River Valley, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Magiera, Tadeusz, E-mail: tadeusz.magiera@ipis.zabrze.pl [Institute of Environmental Engineering, Polish Academy of Sciences, Skłodowskiej-Curie 34, Zabrze (Poland); Mendakiewicz, Maria; Szuszkiewicz, Marcin [Institute of Environmental Engineering, Polish Academy of Sciences, Skłodowskiej-Curie 34, Zabrze (Poland); Jabłońska, Mariola [Department of Geochemistry, Mineralogy and Petrology, Faculty of Earth Sciences, University of Silesia, Sosnowiec (Poland); Chróst, Leszek [Laboratory for Ecological Research, Ekopomiar, Gliwice (Poland)

    2016-10-01

    In the area of Brynica River basin (Upper Silesia, southern Poland) the exploitation and smelting of iron, silver and lead ores was historically documented since early Middle Ages. First investigations showed that metallurgy industry had a large impact from 9th century (AD) until the Second World War. The aim of the study was to use magnetic prospection to detect traces of past mining and ore smelting in Brynica River Valley located in Upper Silesia (southern Poland). The field screening was performed by measurement magnetic susceptibility (κ) on surface and in vertical profiles and was supported locally by gradiometric measurements. Vertical distribution of magnetic susceptibility values was closely associated with the type of soil use. Historical technogenic magnetic particles resulting from exploitation, processing, and smelting of iron, silver, and lead ores were accumulated in the soil layer at the depth 10 to 25 cm. They were represented by sharp-edged particles of slag, coke, as well as various mineralogical forms of iron minerals and aggregates composed of carbon particles, aluminosilicate glass, and single particles of metallic iron. The additional geochemical study in adjacent peat bog supported by radiocarbon dating was also performed. The application of integrated geochemical-magnetic methods to reconstruct the historical accumulation of pollutants in the studied peat bog was effective. The magnetic peak, which was pointed out by magnetic analyses, is consistent with the presence of charcoal and pollution from heavy metals, such as Ag, Cd, Cu, Fe, Pb, or Sn. The results of this work will be helpful for the further study of human's impact on the environment related to the historical and even pre-historical ore exploitation and smelting and also used for better targeting the archeological excavations on such areas. - Highlights: • Due to ferrimagnetic properties of historical slags magnetic prospection is an efficient tool for they localization.

  11. [Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province and evaluation of its ecological risk].

    Science.gov (United States)

    Jin, Shu-Lan; Huang, Yi-Zong; Wang, Fei; Xu, Feng; Wang, Xiao-Ling; Gao, Zhu; Hu, Ying; Qiao Min; Li, Jin; Xiang, Meng

    2015-03-01

    Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province was studied. The results showed that copper mining and smelting could increase the content of rare earth elements in soils and crops. Rare earth elements content in farmland soils of the surrounding Yinshan Lead Zinc Copper Mine and Guixi Smelting Plant varied from 112.42 to 397.02 mg x kg(-1) and 48.81 to 250.06 mg x kg(-1), and the average content was 254.84 mg x kg(-1) and 144.21 mg x kg(-1), respectively. The average contents of rare earth elements in soils in these two areas were 1.21 times and 0.68 times of the background value in Jiangxi province, 1.36 times and 0.77 times of the domestic background value, 3.59 times and 2.03 times of the control samples, respectively. Rare earth elements content in 10 crops of the surrounding Guixi Smelting Plant varied from 0.35 to 2.87 mg x kg(-1). The contents of rare earth elements in the leaves of crops were higher than those in stem and root. The contents of rare earth elements in Tomato, lettuce leaves and radish leaves were respectively 2.87 mg x kg(-1), 1.58 mg x kg(-1) and 0.80 mg x kg(-1), which were well above the hygienic standard limit of rare earth elements in vegetables and fruits (0.70 mg x kg(-1)). According to the health risk assessment method recommended by America Environmental Protection Bureau (USEPA), we found that the residents' lifelong average daily intake of rare earth elements was 17.72 mg x (kg x d)(-1), lower than the critical value of rare earth elements damage to human health. The results suggested that people must pay attention to the impact of rare earth elements on the surrounding environment when they mine and smelt copper ore in Jiangxi.

  12. Technogenic magnetic particles in soils as evidence of historical mining and smelting activity: A case of the Brynica River Valley, Poland

    International Nuclear Information System (INIS)

    Magiera, Tadeusz; Mendakiewicz, Maria; Szuszkiewicz, Marcin; Jabłońska, Mariola; Chróst, Leszek

    2016-01-01

    In the area of Brynica River basin (Upper Silesia, southern Poland) the exploitation and smelting of iron, silver and lead ores was historically documented since early Middle Ages. First investigations showed that metallurgy industry had a large impact from 9th century (AD) until the Second World War. The aim of the study was to use magnetic prospection to detect traces of past mining and ore smelting in Brynica River Valley located in Upper Silesia (southern Poland). The field screening was performed by measurement magnetic susceptibility (κ) on surface and in vertical profiles and was supported locally by gradiometric measurements. Vertical distribution of magnetic susceptibility values was closely associated with the type of soil use. Historical technogenic magnetic particles resulting from exploitation, processing, and smelting of iron, silver, and lead ores were accumulated in the soil layer at the depth 10 to 25 cm. They were represented by sharp-edged particles of slag, coke, as well as various mineralogical forms of iron minerals and aggregates composed of carbon particles, aluminosilicate glass, and single particles of metallic iron. The additional geochemical study in adjacent peat bog supported by radiocarbon dating was also performed. The application of integrated geochemical-magnetic methods to reconstruct the historical accumulation of pollutants in the studied peat bog was effective. The magnetic peak, which was pointed out by magnetic analyses, is consistent with the presence of charcoal and pollution from heavy metals, such as Ag, Cd, Cu, Fe, Pb, or Sn. The results of this work will be helpful for the further study of human's impact on the environment related to the historical and even pre-historical ore exploitation and smelting and also used for better targeting the archeological excavations on such areas. - Highlights: • Due to ferrimagnetic properties of historical slags magnetic prospection is an efficient tool for they localization.

  13. Cd, Pb, and Zn mobility and (bio)availability in contaminated soils from a former smelting site amended with biochar.

    Science.gov (United States)

    Lomaglio, Tonia; Hattab-Hambli, Nour; Miard, Florie; Lebrun, Manhattan; Nandillon, Romain; Trupiano, Dalila; Scippa, Gabriella Stefania; Gauthier, Arnaud; Motelica-Heino, Mikael; Bourgerie, Sylvain; Morabito, Domenico

    2017-07-20

    Biochar is a potential candidate for the remediation of metal(loid)-contaminated soils. However, the mechanisms of contaminant-biochar retention and release depend on the amount of soil contaminants and physicochemical characteristics, as well as the durability of the biochar contaminant complex, which may be related to the pyrolysis process parameters. The objective of the present study was to evaluate, in a former contaminated smelting site, the impact of two doses of wood biochar (2 and 5% w/w) on metal immobilization and/or phytoavailability and their effectiveness in promoting plant growth in mesocosm experiments. Different soil mixtures were investigated. The main physicochemical parameters and the Cd, Pb, and Zn contents were determined in soil and in soil pore water. Additionally, the growth, dry weight, and metal concentrations were analyzed in the different dwarf bean plant (Phaseolus vulgaris L.) organs tested. Results showed that the addition of biochar at two doses (2 and 5%) improved soil conditions by increasing soil pH, electrical conductivity, and water holding capacity. Furthermore, the application of biochar (5%) to metal-contaminated soil reduced Cd, Pb, and Zn mobility and availability, and hence their accumulation in the different P. vulgaris L. organs. In conclusion, the data clearly demonstrated that biochar application can be effectively used for Cd, Pb, and Zn immobilization, thereby reducing their bioavailability and phytotoxicity.

  14. Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

    Science.gov (United States)

    Guo, Zhengqi; Pan, Jian; Zhu, Deqing; Zhang, Feng

    2018-02-01

    In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO2-Al2O3-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.

  15. Material and energy flows in rotary kiln-electric furnace smelting of ferronickel alloy with energy saving

    International Nuclear Information System (INIS)

    Liu, Peng; Li, Baokuan; Cheung, Sherman C.P.; Wu, Wenyuan

    2016-01-01

    Highlights: • Establish the synergy relationship of material and energy in key RKEF processes. • Develop an analysis model to study energy saving with internal cycling of energy. • Analyze material and energy flow parameters and assess its associated synergy effect. • A methodology to evaluate the synergy and design indices of RKEF processes. - Abstract: An energy saving strategy with two energy saving measures has been proposed for reducing energy loss in the rotary kiln-electric furnace (RKEF) for the smelting of ferronickel alloy. One of the measures is to recover the waste heat of exhaust gas from the rotary kiln for preheating and dehydrating the wet laterite ores in the rotary dryer. Another measure is to recycle the furnace gas from the electric furnace into the rotary kiln as fuel. Based on the mass conservation and energy conservation laws, an analysis model of material and energy flows has been developed to understand the potential energy saving with the internal cycling of material and energy in the RKEF process. The analysis model not only considers the energy efficiency but also assess the synergy degree of system. Furthermore, the model also predicts the ratio of raw materials and the energy flow distribution to investigate residual heat and energy and analyze the effects of nickel content on energy flow. Finally, the evaluation methodology of synergy and the technic indices are also presented. Through the investigation of the synergy effect, the performance of the RKEF process can be evaluated and quantified for performance optimization in future.

  16. [Evaluation and source analysis of the mercury pollution in soils and vegetables around a large-scale zinc smelting plant].

    Science.gov (United States)

    Liu, Fang; Wang, Shu-Xiao; Wu, Qing-Ru; Lin, Hai

    2013-02-01

    The farming soil and vegetable samples around a large-scale zinc smelter were collected for mercury content analyses, and the single pollution index method with relevant regulations was used to evaluate the pollution status of sampled soils and vegetables. The results indicated that the surface soil and vegetables were polluted with mercury to different extent. Of the soil samples, 78% exceeded the national standard. The mercury concentration in the most severely contaminated area was 29 times higher than the background concentration, reaching the severe pollution degree. The mercury concentration in all vegetable samples exceeded the standard of non-pollution vegetables. Mercury concentration, in the most severely polluted vegetables were 64.5 times of the standard, and averagely the mercury concentration in the vegetable samples was 25.4 times of the standard. For 85% of the vegetable samples, the mercury concentration, of leaves were significantly higher than that of roots, which implies that the mercury in leaves mainly came from the atmosphere. The mercury concentrations in vegetable roots were significantly correlated with that in soils, indicating the mercury in roots was mainly from soil. The mercury emissions from the zinc smelter have obvious impacts on the surrounding soils and vegetables. Key words:zinc smelting; mercury pollution; soil; vegetable; mercury content

  17. Lead in residential soil and dust in a mining and smelting district in northern Armenia: a pilot study

    International Nuclear Information System (INIS)

    Petrosyan, Varduhi; Orlova, Anna; Dunlap, Charles E.; Babayan, Emil; Farfel, Mark; Braun, Margrit von

    2004-01-01

    This pilot study of sources of lead exposure in residential settings was conducted in a mining and smelting district in northern Armenia. Samples of exterior soil and dust and interior house dust were collected in and around apartment buildings in Alaverdi where the country's largest polymetallic smelter is located, and in nearby mining towns of Aghtala and Shamlugh. The NITON XL-723 Multi-Element XRF analyzer was used for lead testing. Lead levels in samples from Alaverdi were higher than those in Shamlugh and Aghtala. In all three towns, the highest lead levels were found in loose exterior dust samples, and lead concentrations in yard soil were higher than those in garden soil. Many soil samples (34%) and the majority of loose dust samples (77%) in Alaverdi exceeded the US Environmental Protection Agency standard of 400 mg/kg for bare soil in children's play areas. In addition, 36% of floor dust samples from apartments in Alaverdi exceeded the US Environmental Protection Agency standard of 40 μg/ft 2 for lead loading in residential floor dust. The Armenian Ministry of Health and other interested agencies are being informed about the findings of the study so that they can consider and develop educational and preventive programs including blood lead screening among sensitive populations

  18. Numerical Investigation on the Impact of Anode Change on Heat Transfer and Fluid Flow in Aluminum Smelting Cells

    Science.gov (United States)

    Wang, Qiang; Gosselin, Louis; Fafard, Mario; Peng, Jianping; Li, Baokuan

    2016-04-01

    In order to understand the impact of anode change on heat transfer and magnetohydrodynamic flow in aluminum smelting cells, a transient three-dimensional (3D) coupled mathematical model has been developed. The solutions of the mass, momentum, and energy conservation equations were simultaneously implemented by the finite volume method with full coupling of the Joule heating and Lorentz force through solving the electrical potential equation. The volume of fluid approach was employed to describe the two-phase flow. The phase change of molten electrolyte (bath) as well as molten aluminum (metal) was modeled by an enthalpy-based technique, where the mushy zone is treated as a porous medium with a porosity equal to the liquid fraction. The effect of the new anode temperature on recovery time was also analyzed. A reasonable agreement between the test data and simulated results is obtained. The results indicate that the temperature of the bath under cold anodes first decreases reaching the minimal value and rises under the effect of increasing Joule heating, and finally returns to steady state. The colder bath decays the velocity, and the around ledge becomes thicker. The lowest temperature of the bath below new anodes increases from 1118 K to 1143 K (845 °C to 870 °C) with the new anode temperature ranging from 298 K to 498 K (25°C to 225°C), and the recovery time reduces from 22.5 to 20 hours.

  19. Geostatistical approach for assessing soil volumes requiring remediation: validation using lead-polluted soils underlying a former smelting works.

    Science.gov (United States)

    Demougeot-Renard, Helene; De Fouquet, Chantal

    2004-10-01

    Assessing the volume of soil requiring remediation and the accuracy of this assessment constitutes an essential step in polluted site management. If this remediation volume is not properly assessed, misclassification may lead both to environmental risks (polluted soils may not be remediated) and financial risks (unexpected discovery of polluted soils may generate additional remediation costs). To minimize such risks, this paper proposes a geostatistical methodology based on stochastic simulations that allows the remediation volume and the uncertainty to be assessed using investigation data. The methodology thoroughly reproduces the conditions in which the soils are classified and extracted at the remediation stage. The validity of the approach is tested by applying it on the data collected during the investigation phase of a former lead smelting works and by comparing the results with the volume that has actually been remediated. This real remediated volume was composed of all the remediation units that were classified as polluted after systematic sampling and analysis during clean-up stage. The volume estimated from the 75 samples collected during site investigation slightly overestimates (5.3% relative error) the remediated volume deduced from 212 remediation units. Furthermore, the real volume falls within the range of uncertainty predicted using the proposed methodology.

  20. Determination of the main parameters of the cyclone separator of the flue gas produced during the smelting of secondary aluminum

    Science.gov (United States)

    Matusov, Jozef; Gavlas, Stanislav

    2016-06-01

    One way how is possible to separate the solid particulate pollutants from the flue gas is use the cyclone separators. The cyclone separators are very frequently used separators due to the simplicity of their design and their low operating costs. Separation of pollutants in the form of solids is carried out using three types of forces: inertia force, centrifugal force, gravity force. The main advantage is that cyclone consist of the parts which are resistant to wear and have long life time, e.g. various rotating and sliding parts. Mostly are used as pre-separators, because they have low efficiency in the separation of small particles. Their function is to separate larger particles from the flue gases which are subsequently cleaned in the other device which is capable of removing particles smaller than 1 µm, which is limiting size of particle separation. The article will deal with the issue of calculating the basic dimensions and main parameters of the cyclone separator from flue gas produced during the smelting of secondary aluminum.

  1. Planktivory in the changing Lake Huron zooplankton community: Bythotrephes consumption exceeds that of Mysis and fish

    Science.gov (United States)

    Bunnell, D.B.; Hunter, R. Douglas; Warner, D.M.; Chriscinske, M.A.; Roseman, E.F.

    2011-01-01

    Oligotrophic lakes are generally dominated by calanoid copepods because of their competitive advantage over cladocerans at low prey densities. Planktivory also can alter zooplankton community structure. We sought to understand the role of planktivory in driving recent changes to the zooplankton community of Lake Huron, a large oligotrophic lake on the border of Canada and the United States. We tested the hypothesis that excessive predation by fish (rainbow smelt Osmerus mordax, bloater Coregonus hoyi) and invertebrates (Mysis relicta, Bythotrephes longimanus) had driven observed declines in cladoceran and cyclopoid copepod biomass between 2002 and 2007. We used a field sampling and bioenergetics modelling approach to generate estimates of daily consumption by planktivores at two 91-m depth sites in northern Lake Huron, U.S.A., for each month, May-October 2007. Daily consumption was compared to daily zooplankton production. Bythotrephes was the dominant planktivore and estimated to have eaten 78% of all zooplankton consumed. Bythotrephes consumption exceeded total zooplankton production between July and October. Mysis consumed 19% of all the zooplankton consumed and exceeded zooplankton production in October. Consumption by fish was relatively unimportant - eating only 3% of all zooplankton consumed. Because Bythotrephes was so important, we explored other consumption estimation methods that predict lower Bythotrephes consumption. Under this scenario, Mysis was the most important planktivore, and Bythotrephes consumption exceeded zooplankton production only in August. Our results provide no support for the hypothesis that excessive fish consumption directly contributed to the decline of cladocerans and cyclopoid copepods in Lake Huron. Rather, they highlight the importance of invertebrate planktivores in structuring zooplankton communities, especially for those foods webs that have both Bythotrephes and Mysis. Together, these species occupy the epi-, meta- and

  2. Great lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2012

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The assessment of prey fish stocks in the Great Lakes have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, bottom trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique in one or more important aspects, direct comparison of prey fish catches among lakes is not straightforward. However, all of the assessments produce indices of abundance or biomass that can be standardized to facilitate comparisons of status and trends across all the Great Lakes. In this report, population indices were standardized to the highest value for a time series within each lake for the following principal prey species: cisco (Coregonus artedi), bloater (C. hoyi), rainbow smelt (Osmerus mordax), and alewife (Alosa pseudoharengus). Indices were also provided for round goby (Neogobius melanostomus), an invasive fish that has proliferated throughout the basin over the past 18 years. These standardized indices represent the best available long-term indices of relative abundance for these fishes across all of the Great Lakes. In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. In keeping with this intent, tables, references, and a detailed discussion were omitted.

  3. Saturated Branched Chain, Normal Odd-Carbon-Numbered, and n-3 (Omega-3) Polyunsaturated Fatty Acids in Freshwater Fish in the Northeastern United States.

    Science.gov (United States)

    Wang, Dong Hao; Jackson, James R; Twining, Cornelia; Rudstam, Lars G; Zollweg-Horan, Emily; Kraft, Clifford; Lawrence, Peter; Kothapalli, Kumar; Wang, Zhen; Brenna, J Thomas

    2016-10-04

    The fatty acid profiles of wild freshwater fish are poorly characterized as a human food source for several classes of fatty acids, particularly for branched chain fatty acids (BCFA), a major bioactive dietary component known to enter the US food supply primarily via dairy and beef fat. We evaluated the fatty acid content of 27 freshwater fish species captured in the northeastern US with emphasis on the BCFA and bioactive polyunsaturated fatty acids (PUFA) most associated with fish, specifically n-3 (omega-3) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Mean BCFA content across all species was 1.0 ± 0.5% (mean ± SD) of total fatty acids in edible muscle, with rainbow smelt (Osmerus mordax) and pumpkinseed (Lepomis gibbosus) the highest at >2% BCFA. In comparison, EPA + DHA constituted 28% ± 7% of total fatty acids. Across all fish species, the major BCFA were iso-15:0, anteiso-15:0, iso-16:0, iso-17:0 and anteiso-17:0. Fish skin had significantly higher BCFA content than muscle tissues, at 1.8% ± 0.7%, but lower EPA and DHA. Total BCFA in fish skins was positively related with that in muscle (r 2 = 0.6). The straight chain saturates n-15:0 and n-17:0 which have been identified previously as markers for dairy consumption were relatively high with means of 0.4% and 0.6%, respectively, and may be an underappreciated marker for seafood intake. Consuming a standardized portion, 70 g (2.5 oz), of wild freshwater fish contributes only small amounts of BCFA, 2.5-24.2 mg, to the American diet, while it adds surprisingly high amounts of EPA + DHA (107 mg to 558 mg).

  4. Delta smelt habitat in the San Francisco Estuary: A reply to Manly, Fullerton, Hendrix, and Burnham’s “Comments on Feyrer et al. Modeling the effects of future outflow on the abiotic habitat of an imperiled estuarine fish"

    Science.gov (United States)

    Feyrer, Frederick V.; Newman, Ken B.; Nobriga, Matthew; Sommer, Ted

    2016-01-01

    Manly et al. (2015) commented on the approach we (Feyrer et al. 2011) used to calculate an index of the abiotic habitat of delta smelt Hypomesus transpacificus. The delta smelt is an annual fish species endemic to the San Francisco Estuary (SFE) in California, USA. Conserving the delta smelt population while providing reliability to California’s water supply with water diverted from the SFE ecosystem is a major management and policy issue. Feyrer et al. (2011) evaluated historic and projected future abiotic habitat conditions for delta smelt. Manly et al. (2015) specifically commented regarding the following: (1) use of an independent abundance estimate, (2) spatial bias in the habitat index, and (3) application of the habitat index to future climate change projections. Here, we provide our reply to these three topics. While we agree that some of the concepts raised by Manly et al. (2015) have the potential to improve habitat assessments and their application to climate change scenarios as knowledge is gained, we note that the Feyrer et al. (2011) delta smelt habitat index is essentially identical to one reconstructed using Manly et al.’s (2015) preferred approach (their model 8), as shown here in Fig. 1.

  5. Effect of solution heat treatment on the precipitation behavior and strengthening mechanisms of electron beam smelted Inconel 718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Shi, Shuang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Yang, Jenn-Ming [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wang, Yinong [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Li, Jiayan; You, Qifan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2017-03-24

    Inconel 718 superalloy was fabricated by electron beam smelting (EBS) technique. The effect of solution heat treatment on the precipitation behavior and mechanical properties of EBS 718 superalloys were studied, the strengthening mechanisms were analyzed and related to the mechanical properties. The results indicate that the optimized microstructures can be acquired by means of EBS, which is attributed to the rapid cooling rate of approximately 280 ℃/min. The solution heat treatment shows a great impact on the microstructures, precipitation behavior and mechanical properties of EBS 718 superalloy. The γ'' phase shows an apt to precipitate at relatively lower solution temperatures followed by aging, while the γ' precipitates are prone to precipitate at higher temperatures. When solution treated at 1150 ℃, the γ' precipitates are dispersively distributed in the matrix with size and volume fraction of 8.43 nm and 21.66%, respectively, a Vickers hardness of approximately 489 HV{sub 0.1} is observed for the aged superalloy. The precipitation strengthening effect of EBS 718 superalloy could be elucidated by considering the interaction between the dislocations and γ''/γ' precipitates. The shearing of γ' is resisted by the coherency strengthening and formation of antiphase boundary (APB), which shows equal effect as weakly coupled dislocation (WCD) model. And for γ'', the strengthening effect is much more prominent with the primary strengthening mechanism of ordering. Moreover, it is interestingly found that the strengthening mechanism of stacking fault (SF) shearing coexists with APB shearing, and SF shearing plays a major role in strengthening of EBS 718 superalloy.

  6. Effects of heavy metal pollution from mining and smelting on enchytraeid communities under different land management and soil conditions.

    Science.gov (United States)

    Kapusta, Paweł; Sobczyk, Łukasz

    2015-12-01

    We studied enchytraeid communities in several habitats polluted by heavy metals from Zn-Pb mining and smelting activities. We sampled 41 sites that differed in the type of substratum (carbonate rock, metal-rich carbonate mining waste, siliceous sand) and land management (planting Scots pine, topsoiling, leaving to natural succession), and the distance from the smelter. Our main aims were to determine which pollution variables and natural factors most influenced enchytraeid species composition, richness and density, and examine what was the effect of planting Scots pine (reclamation) on enchytraeid communities. The soils harboured on average 1 to 5 enchytraeid species and 700 to 18,300 individuals per square metre, depending on the habitat. These figures were generally lower than those reported from unpolluted regions. Redundancy and multiple regression analyses confirmed the negative impact of heavy metal pollution on both enchytraeid community structure and abundance. Among pollution variables, the distance from the smelter best explained the variation in enchytraeid communities. The concentrations of heavy metals in the soil had less (e.g. total Pb and exchangeable Zn) or negligible (water-soluble forms) explanatory power. Natural soil properties were nearly irrelevant for enchytraeids, except for soil pH, which determined the species composition. Plant species richness was an important explanatory variable, as it positively affected most parameters of enchytraeid community. The results of two-by-two factorial comparisons (planting Scots pine vs. natural succession; carbonate mining waste vs. siliceous sand) suggest that reclamation can improve soil quality for biota, since it increased the diversity and abundance of enchytraeids; this effect was not dependent on the type of substratum. In conclusion, enchytraeids responded negatively to heavy metal pollution and their response was consistent and clear. These animals can be used as indicators of metal toxicity

  7. Cleaning of a copper matte smelting slag from a water-jacket furnace by direct reduction of heavy metals.

    Science.gov (United States)

    Maweja, Kasonde; Mukongo, Tshikele; Mutombo, Ilunga

    2009-05-30

    Cleaning experiments of a copper matte smelting slag from the water-jacket furnace was undertaken by direct reduction in a laboratory-scale electric furnace. The effects of coal-to-slag ratio, w, and the reduction time, t, were considered for two different coal/slag mixing procedures. In the first procedure, metallurgical coal was added to the molten slag, whereas in the second procedure, coal was premixed with the solid slag before charging into the furnace. The recovery of heavy metals (Cu, Co), and the fuming of Pb and Zn were investigated. Contamination of the metal phase by iron and the acidity index of the final slag were analysed as these may impede the economical viability of the process. The lower w value of 2.56% yielded a recovery rate of less than 60% for copper and less than 50% for cobalt, and around 70% for zinc. However, increasing w to 5% allowed the recovery of 70-90% for Cu, Co and Zn simultaneously after 30-60 min reduction of the molten slag. After reduction, the cleaned slags contained only small amounts of copper and cobalt (zinc was efficient as the %Pb of the residual slag dropped to levels lower than 0.04% after 30 min of reduction. Ninety percent of the lead was removed from the initial slag and collected in the dusts. The zinc content of the cleaned slags quickly dropped to between 1 and 3 wt% from the initial 8.2% after 30 min reduction for w value of 5 and after 60 min reduction for w value of 2.56. The dusts contained about 60% Zn and 10% Pb. Recovery of lead from fuming of the slag was higher than 90% in all the experimental conditions considered in this study.

  8. Conservation of Native Fishes of the San Francisco Estuary: Considerations for Artificial Propagation of Chinook Salmon, Delta Smelt, and Green Sturgeon

    Directory of Open Access Journals (Sweden)

    Joshua A. Israel

    2011-04-01

    Full Text Available Many native fishes in the San Francisco Estuary and its watersheds have reached all-time low abundances. Some of these declining species (e.g., Chinook salmon Oncorhynchus tschawytscha have been under artificial propagation for decades. For others (e.g., delta smelt, Hypomesus transpacificus, and green sturgeon, Acipenser medirostris, this management option is just beginning to be discussed and implemented. Propagation strategies, in which organisms spend some portion of their lives in captivity, pose well-documented genetic and ecological threats to natural populations. Negative impacts of propagation have been documented for all Central Valley Chinook salmon runs, but limited efforts have been made to adapt hatchery operations to minimize the genetic and ecological threats caused by propagated fishes. A delta smelt propagation program is undergoing intensive design and review for operations and monitoring. However, if limiting factors facing this species in its estuarine habitat are not effectively addressed, captive propagation may not be a useful conservation approach, regardless of how carefully the propagation activity is designed or monitored. Scientifically defensible, ecologically based restoration programs that include monitoring and research aimed at quantifying natural population vital rates should be fully implemented before there is any attempt to supplement natural populations of delta smelt. Green sturgeon are also likely to face risks from artificial propagation if a large–scale program is implemented before this species’ limiting factors are better understood. In each of these cases, restoring habitats, and reducing loss from human actions, are likely to be the best strategy for rebuilding and supporting self–sustaining populations.

  9. Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

    Science.gov (United States)

    Shi, Jianwu; Deng, Hao; Bai, Zhipeng; Kong, Shaofei; Wang, Xiuyan; Hao, Jiming; Han, Xinyu; Ning, Ping

    2015-05-15

    107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on

  10. Post-depositional redistribution of trace metals in reservoir sediments of a mining/smelting-impacted watershed (the Lot River, SW France)

    International Nuclear Information System (INIS)

    Audry, Stephane; Grosbois, Cecile; Bril, Hubert; Schaefer, Joerg; Kierczak, Jakub; Blanc, Gerard

    2010-01-01

    Mining/smelting wastes and reservoir sediment cores from the Lot River watershed were studied using mineralogical (XRD, SEM-EDS, EMPA) and geochemical (redox dynamics, selective extractions) approaches to characterize the main carrier phases of trace metals. These two approaches permitted determining the role of post-depositional redistribution processes in sediments and their effects on the fate and mobility of trace metals. The mining/smelting wastes showed heterogeneous mineral compositions with highly variable contents of trace metals. The main trace metal-bearing phases include spinels affected by secondary processes, silicates and sulfates. The results indicate a clear change in the chemical partitioning of trace metals between the reservoir sediments upstream and downstream of the mining/smelting activities, with the downstream sediments showing a 2-fold to 5-fold greater contribution of the oxidizable fraction. This increase was ascribed to stronger post-depositional redistribution of trace metals related to intense early diagenetic processes, including dissolution of trace metal-bearing phases and precipitation of authigenic sulfide phases through organic matter (OM) mineralization. This redistribution is due to high inputs (derived from mining/smelting waste weathering) at the water-sediment interface of (i) dissolved SO 4 promoting more efficient OM mineralization, and (ii) highly reactive trace metal-bearing particles. As a result, the main trace metal-bearing phases in the downstream sediments are represented by Zn- and Fe-sulfides, with minor occurrence of detrital zincian spinels, sulfates and Fe-oxyhydroxides. Sequestration of trace metals in sulfides at depth in reservoir sediments does not represent long term sequestration owing to possible resuspension of anoxic sediments by natural (floods) and/or anthropogenic (dredging, dam flush) events that might promote trace metal mobilization through sulfide oxidation. It is estimated that, during a major

  11. A refined ecological risk assessment for California red-legged frog, Delta smelt, and California tiger salamander exposed to malathion.

    Science.gov (United States)

    Clemow, Yvonne H; Manning, Gillian E; Breton, Roger L; Winchell, Michael F; Padilla, Lauren; Rodney, Sara I; Hanzas, John P; Estes, Tammara L; Budreski, Katherine; Toth, Brent N; Hill, Katie L; Priest, Colleen D; Teed, R Scott; Knopper, Loren D; Moore, Dwayne Rj; Stone, Christopher T; Whatling, Paul

    2018-03-01

    The California red-legged frog (CRLF), Delta smelt (DS), and California tiger salamander (CTS) are 3 species listed under the United States Federal Endangered Species Act (ESA), all of which inhabit aquatic ecosystems in California. The US Environmental Protection Agency (USEPA) has conducted deterministic screening-level risk assessments for these species potentially exposed to malathion, an organophosphorus insecticide and acaricide. Results from our screening-level analyses identified potential risk of direct effects to DS as well as indirect effects to all 3 species via reduction in prey. Accordingly, for those species and scenarios in which risk was identified at the screening level, we conducted a refined probabilistic risk assessment for CRLF, DS, and CTS. The refined ecological risk assessment (ERA) was conducted using best available data and approaches, as recommended by the 2013 National Research Council (NRC) report "Assessing Risks to Endangered and Threatened Species from Pesticides." Refined aquatic exposure models including the Pesticide Root Zone Model (PRZM), the Vegetative Filter Strip Modeling System (VFSMOD), the Variable Volume Water Model (VVWM), the Exposure Analysis Modeling System (EXAMS), and the Soil and Water Assessment Tool (SWAT) were used to generate estimated exposure concentrations (EECs) for malathion based on worst-case scenarios in California. Refined effects analyses involved developing concentration-response curves for fish and species sensitivity distributions (SSDs) for fish and aquatic invertebrates. Quantitative risk curves, field and mesocosm studies, surface-water monitoring data, and incident reports were considered in a weight-of-evidence approach. Currently, labeled uses of malathion are not expected to result in direct effects to CRLF, DS or CTS, or indirect effects due to effects on fish and invertebrate prey. Integr Environ Assess Manag 2018;14:224-239. © 2017 The Authors. Integrated Environmental Assessment and

  12. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chunxia, E-mail: cxzhang@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Qiao Qingqing [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Piper, John D.A. [Geomagnetism Laboratory, Department of Earth and Ocean Science, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Huang, Baochun [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China)

    2011-10-15

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: > Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. > HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. > A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. > The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  13. Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

    Directory of Open Access Journals (Sweden)

    Tao Jiang

    2016-05-01

    Full Text Available The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction ofiron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without significant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO2 can be used by the acid leaching method.

  14. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    International Nuclear Information System (INIS)

    Zhang Chunxia; Qiao Qingqing; Piper, John D.A.; Huang, Baochun

    2011-01-01

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: → Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. → HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. → A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. → The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  15. Distribution and transfer of potentially toxic metal(loid)s in Juncus effusus from the indigenous zinc smelting area, northwest region of Guizhou Province, China.

    Science.gov (United States)

    Peng, Yishu; Chen, Jun; Wei, Huairui; Li, Shibin; Jin, Tao; Yang, Ruidong

    2018-05-15

    We collected samples (i.e., the aerial parts and roots of Juncus effusus and their growth media) in the indigenous zinc smelting area in the northwest region of Guizhou Province, China, and we measured and analyzed potentially toxic metal(loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb and zinc, Zn) in these samples. The results include the following: First, there is a high concentration of one or more potentially toxic metal(loid)s in the slag and surrounding soil in the research area. This situation might be caused by metal(loid) damage or contamination due to the circumstances. Additionally, Juncus effusus in the indigenous zinc smelting area are contaminated by some potentially toxic metal(loid)s; since they are used for Chinese medical materials, it is especially significant that their As, Cd and Pb concentrations are greater than their limited standard values. Finally, both the bioconcentration factors and transfer factors for most potentially toxic metal(loid)s in Juncus effusus are less than 1 in the study area. Therefore, we suggest that Juncus effusus could be used for phytostabilization or as a pioneer plant for phytoremediation of potentially toxic metal(loid)s because it has a tolerance and exclusion mechanism for these metal(loid)s in the research district. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  17. Structure and diversity of ground mesofauna inUlmus and Populus consortia in the industrial areas of mining and smelting complex of krivyi rig basin

    Directory of Open Access Journals (Sweden)

    V. V. Kachinskaya

    2010-05-01

    Full Text Available The structure and biological diversity of ground mesofauna on a consortium level of organisation of ecosystems are considered. Indicators of structural organisation and biodiversity of ground mesofauna were analised in Ulmus and Populus consortia in the conditions of industrial territories of mining and smelting complex of Krivyi Rig Basin. It is established that taxonomical structure of ground mesofauna is characterised by insignificant number and quantity of taxonomical groups. Prevalence of hortobionts and herpetobionts in morpho-ecological structure of the community testifies to their attachment to consortium’s determinants and influence of steppe climate on its structure. Dominance of phytophages and polyphages in trophic structure is caused by a combination of consortium determinants specificity and «a zone source» of the fauna formations. The structural organisation of ground mesofauna in consortia of Ulmus and Populus in the conditions of industrial sites is characterised by simplified taxonomical structure with low biodiversity at all levels.

  18. The effect of smelting time and composition of palm kernel shell charcoal reductant toward extractive Pomalaa nickel laterite ore in mini electric arc furnace

    Science.gov (United States)

    Sihotang, Iqbal Huda; Supriyatna, Yayat Iman; Ismail, Ika; Sulistijono

    2018-04-01

    Indonesia is a country that is rich in natural resources. Being a third country which has a nickel laterite ore in the world after New Caledonia and Philippines. However, the processing of nickel laterite ore to increase its levels in Indonesia is still lacking. In the processing of nickel laterite ore into metal, it can be processed by pyrometallurgy method that typically use coal as a reductant. However, coal is a non-renewable energy and have high enough levels of pollution. One potentially replace is the biomass, that is a renewable energy. Palm kernel shell are biomass that can be used as a reductant because it has a fairly high fix carbon content. This research aims to make nickel laterite ores become metal using palm kernel shell charcoal as reductant in mini electric arc furnace. The result show that the best smelting time of this research is 60 minutes with the best composition of the reductant is 2,000 gram.

  19. Determination of the elemental composition of aerosol samples in the working environment of a secondary lead smelting company in Nigeria using EDXRF technique

    International Nuclear Information System (INIS)

    Obiajunwa, E.I.; Johnson-Fatokun, F.O.; Olaniyi, H.B.; Olowole, A.F.

    2002-01-01

    Energy dispersive X-ray fluorescence technique was employed to determine the concentrations of elements in aerosol samples collected in the working environment of a secondary lead smelting company in Nigeria. Sampling was done using Whatman-41 cellulose filters mounted in Negretti air samplers at 10 locations within the factory. The concentrations of eight elements (K, Ca, Ti, Mn, Fe, Cu, Zn and Pb) were determined. The TSP values ranged from 70 to 7963 μg/m 3 and the concentration of Pb was found to be between 2.98 and 538.47 μg/m 3 . The high Pb concentration is a danger signal to the health of the factory workers

  20. Standardization of the process of smelting for sands with self-forgeling resins in the Military Industry Santa Bárbara Factory

    Directory of Open Access Journals (Sweden)

    Lina Consuelo Carvajal-Fernández

    2014-12-01

    Full Text Available This article describes the standardization of the smelting process for sands with self-forgeling resins in the Military Industry Santa Barbara Factory. The molding process was studied in the Smelter for six months, to set standards for workforce and raw materials, so that would allow truthfully evaluate the costs per kilogram of casting. 41 pieces of civil and military sectors throughout the development of the project were worked. Finally both standards were evaluated, labor as raw material for different parts, with results was evidenced improved process, essentially in workforce, while in raw material standards did not show significantly change, in this case is corroborated that existing ones are applicable to the process

  1. Interactions between walleyes and smallmouth bass in a Missouri River reservoir with consideration of the influence of temperature and prey

    Science.gov (United States)

    Wuellner, Melissa R.; Chipps, Steven R.; Willis, David W.; Adams, Wells E.

    2010-01-01

    Walleyes Sander vitreus are the most popular fish among South Dakota anglers, but smallmouth bass Micropterus dolomieu were introduced to provide new angling opportunities. Some walleye anglers have reported reductions in the quality of walleye fisheries since the introduction of smallmouth bass and attribute this to the consumption of young walleyes by smallmouth bass and competition for shared prey resources. We quantified the diets of walleyes and smallmouth bass in the lower reaches of Lake Sharpe (a Missouri River reservoir), calculated the diet overlap between the two predators, and determined whether they partitioned shared prey based on size. We also quantified walleye diets in the upper reach of the reservoir, which has a different prey base and allowed us to compare the growth rates of walleyes within Lake Sharpe. Age-0 gizzard shad Dorosoma cepedianum composed a substantial proportion of the diets of both predators, regardless of location, for most of the growing season; the patterns in shad vulnerability appeared to drive the observed patterns in diet overlap. Smallmouth bass appeared to consume a smaller size range of gizzard shad than did walleyes, which consumed a wide range. Smallmouth bass consumed Sander spp. in some months, but in very low quantities. Given that global climate change is expected to alter the population and community dynamics in Great Plains reservoirs, we also used a bioenergetics approach to predict the potential effects of limiting prey availability (specifically, the absence of gizzard shad and rainbow smelt Osmerus mordax) and increased water temperatures (as projected from global climate change models) on walleye and smallmouth bass growth. The models indicated that the absence of rainbow smelt from the diets of walleyes in upper Lake Sharpe would reduce growth but that the absence of gizzard shad would have a more marked negative effect on both predators at both locations. The models also indicated that higher

  2. Effect of Calcium Oxide on the Crushing Strength, Reduction, and Smelting Performance of High-Chromium Vanadium–Titanium Magnetite Pellets

    Directory of Open Access Journals (Sweden)

    Gongjin Cheng

    2017-05-01

    Full Text Available The effect of calcium oxide on the crushing strength, reduction, and smelting performance of high-chromium vanadium–titanium magnetite pellets (HCVTMP was studied in this work. The main characterization methods of an electronic universal testing machine (EUTM, X-ray fluorescent (XRF, inductively-coupled plasma-atomic emission spectroscopy (ICP-AES, X-ray diffraction (XRD, and scanning electron microscope-energy disperse spectroscopy (SEM-EDS were employed. The crushing strength was affected by the mineral phases generated during oxidative baking and the subsequently-formed pellet microstructures owing to CaO addition. The reduction and smelting properties of HCVTMP with different CaO additives were measured and characterized with different softening-melting-dripping indices. Although HCVTMP showed the highest crushing strength with CaO addition of ca. 2 wt %, more CaO addition may be needed to achieve high permeability of the furnace burdens and a good separation condition of the slag and melted iron. In the formation process of the slag and melted iron, it can be determined that CaO could have a relationship with the transformation behavior of Cr, V, and Ti to some extent, with respect to the predominant chemical composition analysis of ICP-AES and XRF. With the microscopic examination, the restraining formation of Ti(C,N and the promoting formation of CaTiO3 are in accordance with the improved melting-dripping indices, including the decrease of the maximum external static load and gas permeability, and the increase of the melting-dripping zone and dripping difficulty.

  3. Multi-criteria analysis of soil pollution by heavy metals in the vicinity of the Copper Smelting Plant in Bor (Serbia

    Directory of Open Access Journals (Sweden)

    NEVENKA PETROVIĆ

    2011-04-01

    Full Text Available This study highlights the consequences on soil pollution of one hund­red years of manufacturing in the Copper Mining and Smelting Complex RTB-Bor (Serbia. Soil sediments were taken via a probe from the surface layer of the soil at twelve different measuring points. The measuring points were all within 20 km of the smelting plant, which included both urban and rural zones. Soil sampling was performed using a soil core sampler in such way that a core of a soil of radius 5 cm and depth of 30 cm was removed. Subsequently, the samples were analyzed for pH and heavy metal concentrations (Cu, Pb, As, Cd, Mn, Ni and Hg using different spectrometric methods. The obtained results for the heavy metal contents in the samples show high values: 2,540 mg kg-1 Cu; 230 mg kg-1 Pb; 6 mg kg-1 Cd; 530 mg kg-1 Ni; 1,300 mg kg-1 Mn; 260 mg kg-1 As and 0.3 mg kg-1 Hg. In this study, critical zones of polluted soil were iden­tified and ranked according to their metal contents by the multi-criteria deci­sion method Preference Organization Method for Enrichment Evaluation/Geo­metrical Analysis for Interactive Assistance – PROMETHEE/GAIA, which is the preferred multivariate method commonly used in chemometric studies. The ranking results clearly showed that the most polluted zones are at locations holding the vital functions of the town. Therefore, due to the high bioavail­abi­lity of heavy metals through com­plex reactions with organic species in the sediments, consequences for human health could drastically emerge if these metals enter the food chain.

  4. Particle size distributions, size concentration relationships, and adherence to hands of selected geologic media derived from mining, smelting, and quarrying activities

    Energy Technology Data Exchange (ETDEWEB)

    Bergstrom, Carolyn; Shirai, Jeffry; Kissel, John, E-mail: jkissel@uw.edu

    2011-09-15

    Hand-to-mouth activity, especially in children, is a potentially significant pathway of exposure to soil contaminants. Hand-mouthing behavior is of particular concern in areas impacted by mining, smelting, and quarrying activities as these activities may lead to elevated levels of heavy metals in soil. In order to estimate potential exposures to contaminated geologic media attributable to hand-to-mouth contact, it is useful to characterize adherence of those media to skin, as contaminant concentrations in adhered media may differ greatly from unfractionated, whole media concentrations. Such an investigation has been undertaken to aid estimation of exposures to arsenic, cadmium, lead, and zinc in nine different geologic media collected in the Pacific Northwest region of the United States. After establishing the particle size distribution of each medium (fractions < 63 {mu}m, 63-150 {mu}m, 150-250 {mu}m, and 250 {mu}m-2 mm were determined) and target elemental concentrations within each particle size fraction, an active handling protocol involving six volunteers was conducted. Wet media always adhered to a greater extent than dry media and adhered media generally had higher elemental concentrations than bulk media. Regression analyses suggest smaller particle fractions may have higher elemental concentrations. Results of application of a maximum likelihood estimation technique generally indicate that handling of dry media leads to preferential adherence of smaller particle sizes, while handling of wet media does not. Because adhered material can differ greatly in particle size distribution from that found in bulk material, use of bulk concentrations in exposure calculations may lead to poor estimation of actual exposures. Since lead has historically been a metal of particular concern, EPA's Integrated Exposure Uptake Biokinetic (IEUBK) Model was used to examine the potential consequences of evaluating ingestion of the selected media assuming concentrations in

  5. Assessment of environmental and health risks in former polymetallic ore mining and smelting area, Slovakia: Spatial distribution and accumulation of mercury in four different ecosystems.

    Science.gov (United States)

    Árvay, Július; Demková, Lenka; Hauptvogl, Martin; Michalko, Miloslav; Bajčan, Daniel; Stanovič, Radovan; Tomáš, Ján; Hrstková, Miroslava; Trebichalský, Pavol

    2017-10-01

    Former long-term mining and smelting of pollymetallic ores in the Middle Spiš area caused a serious contamination problem of the environment with heavy metals and metalloids, especially mercury (Hg). Several studies have reported concentration of Hg in the area but this paper provides first detailed characterization of Hg contamination of different environmental components in agricultural, forest, grassland and urban ecosystems. The ecosystems are in different distances from emission sources - former mercury and copper smelting plants in NE Slovakia. Total Hg content was studied in soil/substrate samples (n = 234) and characteristic biological samples (Athyrium filix-femina (L.) Roth, Macrolepiota procera (Scop.) Singer, Boletus edulis Bull., Cyanoboletus pulverulentus (Opat.) Gelardi, Vizzini & Simonini, Triticum aestivum (L.), Poa pratensis (L.)) (n = 234) collected in the above-mentioned ecosystems. The level of contamination and environmental risks were assessed by contamination factor (C f ), index of geoaccumulation (I geo ) and potential environmental risk index (PER). To determine the level of transition of Hg from abiotic to biotic environment, bioconcentration factor (BCF) was used. To determine a health risk resulting from regular and long-term consumption of the locally available species, the results of the Hg content were compared with the Provisional Tolerable Weekly Intake (PTWI) for Hg defined by World Health Organization. The results suggest that almost 63% of the area belong to the very high risk category and 80% of the sampling sites shown very high contamination factor. Geoaccumulation index showed that almost 30% of the area is very strongly contaminated and only 8% is not contaminated with Hg. Spearman's correlation relationship confirmed that the values of PER, BCF, C f and I geo decreased with an increasing distance from the pollution source. The percentage of contribution to PTWI ranged between 5.76-69.0% for adults and 11.5-138% for

  6. Heavy metal contamination of arable soil and corn plant in the vicinity of a zinc smelting factory and stabilization by liming.

    Science.gov (United States)

    Hong, Chang Oh; Gutierrez, Jessie; Yun, Sung Wook; Lee, Yong Bok; Yu, Chan; Kim, Pil Joo

    2009-02-01

    The heavy metal contamination in soils and cultivated corn plants affected by zinc smelting activities in the vicinity of a zinc smelting factory in Korea was studied. Soils and corn plants were sampled at the harvesting stage and analyzed for cadmium (Cd) and zinc (Zn) concentration, as well as Cd and Zn fraction and other chemical properties of soils. Cd and Zn were highly accumulated in the surface soils (0-20 cm), at levels higher than the Korean warning criteria (Cd, 1.5; Zn, 300 mg kg(-1)), with corresponding mean values of 1.7 and 407 mg kg(-1), respectively, but these metals decreased significantly with increasing soil depth and distance from the factory, implying that contaminants may come from the factory through aerosol dynamics (Hong et al., Kor J Environ Agr 26(3):204-209, 2007a; Environ Contam Toxicol 52:496-502, 2007b) and not from geological sources. The leaf part had higher Cd and Zn concentrations, with values of 9.5 and 1733 mg kg(-1), compared to the stem (1.6 and 547 mg kg(-1)) and grain (0.18 and 61 mg kg(-1)) parts, respectively. Cd and Zn were higher in the oxidizable fraction, at 38.5% and 46.9% of the total Cd (2.6 mg kg(-1)) and Zn (407 mg kg(-1)), but the exchangeable + acidic fraction of Cd and Zn as the bioavailable phases was low, 0.2 and 50 mg kg(-1), respectively. To study the reduction of plant Cd and Zn uptake by liming, radish (Raphanus sativa L.) was cultivated in one representative field among the sites investigated, and Ca(OH)(2) was applied at rates of 0, 2, 4, and 8 mg ha(-1). Plant Cd and Zn concentrations and NH(4)OAc extractable Cd and Zn concentrations of soil decreased significantly with increasing Ca(OH)(2) rate, since it markedly increases the cation exchange capacity of soil induced by increased pH. As a result, liming in this kind of soil could be an effective countermeasure in reducing the phytoextractability of Cd and Zn.

  7. The utility of Pinus sylvestris L. in dendrochemical investigations: Pollution impact of lead mining and smelting in Darley Dale, Derbyshire, UK

    International Nuclear Information System (INIS)

    Lageard, J.G.A.; Howell, J.A.; Rothwell, J.J.; Drew, I.B.

    2008-01-01

    This research investigates atmospheric pollution from an isolated and increasingly productive lead-smelting site by examining the dendrochemistry of Pinus sylvestris growing in the local environment and at control sites. Tree increment cores and soil in the rooting environment were analysed for lead content. Inter-site comparisons of lead-in-soil suggest that contamination of the soil may be a less important pathway for lead inclusion within wood than pathways via bark or needles. Levels of lead-in-wood (up to 38 mg kg -1 ) are at the upper end of those previously reported. There is evidence of radial translocation of lead towards the heartwood and variability in intra-site dendrochemical records. Mean site lead-in-wood records can however be related to a well-documented pollution chronology and also suggest the importance of local topography in the dispersal and deposition of particulate lead. This study demonstrates that P. sylvestris can be used to estimate the scale and timing of past pollution episodes in similar environmental contexts to those investigated at Darley Dale, where precisely dated pollution chronologies are lacking. - Mean site dendrochemical records for Pinus sylvestris can be used to estimate the general scale and timing of atmospheric pollution episodes

  8. A guidance manual for estimating greenhouse gas emissions from fuel combustion and process-related sources for primary base metals smelting and refining

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    This technical guidance manual is a useful resource for helping the metals industry compile inventories of its greenhouse gas (GHG) emissions. The guidance is consistent with Canada's national GHG accounting methodologies. It provides information to smelters and refiners of base metals on how to estimate their GHG emissions from fuel combustion and specific process-related activities. The base metals group in this manual included copper, nickel, lead, zinc, and cobalt. Fuel combustion includes all stationary combustion activities for generating heat or work, and includes waste incineration if the waste heat is used for energy. It also includes mobile fuel combustion activities such as on-site transportation of raw materials from one process to another. Guidance is provided for carbon dioxide (CO{sub 2}), methane (CH{sub 4}) and nitrous oxide (N{sub 2}O). Process-related activities include specific industrial processes that contribute to GHG emissions. For base metal smelting, this includes CO{sub 2} emissions from use of carbonate reagents, use of reducing agents, electrode consumption, and hydrofluorocarbons (HFC) emissions from use in refrigeration systems. This document also included sections on quality assurance; aspects of uncertainty assessment; verification; and, reporting of emissions information. refs., tabs., figs.

  9. Joint study on smelting reduction. ; Results of elementary study and future studies. Yoyu kangen kyodo kenkyu; Yoso kenkyu no seika to kongo no torikume

    Energy Technology Data Exchange (ETDEWEB)

    1991-03-01

    The paper outlines results of elementary study on the coal direct-use iron-making process and how to tackle with it in future. In the process coal and iron ores are used directly without prior treatments like coking and briquetting. The process is composed of three elements: smelting reducing furnace, preliminary reduction fluidized bed, gas reforming furnace. Making mathematical models as a means of study of the process, material balance and heat balance are calculated. Operational unit requirements are estimated, changing them in the range of 20-60% of the post combustion based on three fundamental processes each of which is composed of one or a combination of the three elements. The total cost is also trially calculated, estimating fixed cost including installation cost, etc. With no big differences in the iron-melting cost excluding by-products in each process, the cost may be reduced by 5-10% of that in the blast furnace process. The elementary study has continued almost satisfactorily and attained the expected target, though there still remain some problems. In 1990 the study started of a pilot plant with a 500t/day capacity. 12 figs.

  10. The utility of Pinus sylvestris L. in dendrochemical investigations: pollution impact of lead mining and smelting in Darley Dale, Derbyshire, UK.

    Science.gov (United States)

    Lageard, J G A; Howell, J A; Rothwell, J J; Drew, I B

    2008-05-01

    This research investigates atmospheric pollution from an isolated and increasingly productive lead-smelting site by examining the dendrochemistry of Pinus sylvestris growing in the local environment and at control sites. Tree increment cores and soil in the rooting environment were analysed for lead content. Inter-site comparisons of lead-in-soil suggest that contamination of the soil may be a less important pathway for lead inclusion within wood than pathways via bark or needles. Levels of lead-in-wood (up to 38mgkg(-1)) are at the upper end of those previously reported. There is evidence of radial translocation of lead towards the heartwood and variability in intra-site dendrochemical records. Mean site lead-in-wood records can however be related to a well-documented pollution chronology and also suggest the importance of local topography in the dispersal and deposition of particulate lead. This study demonstrates that P. sylvestris can be used to estimate the scale and timing of past pollution episodes in similar environmental contexts to those investigated at Darley Dale, where precisely dated pollution chronologies are lacking.

  11. Polycyclic aromatic hydrocarbons in ambient air, surface soil and wheat grain near a large steel-smelting manufacturer in northern China.

    Science.gov (United States)

    Liu, Weijian; Wang, Yilong; Chen, Yuanchen; Tao, Shu; Liu, Wenxin

    2017-07-01

    The total concentrations and component profiles of polycyclic aromatic hydrocarbons (PAHs) in ambient air, surface soil and wheat grain collected from wheat fields near a large steel-smelting manufacturer in Northern China were determined. Based on the specific isomeric ratios of paired species in ambient air, principle component analysis and multivariate linear regression, the main emission source of local PAHs was identified as a mixture of industrial and domestic coal combustion, biomass burning and traffic exhaust. The total organic carbon (TOC) fraction was considerably correlated with the total and individual PAH concentrations in surface soil. The total concentrations of PAHs in wheat grain were relatively low, with dominant low molecular weight constituents, and the compositional profile was more similar to that in ambient air than in topsoil. Combined with more significant results from partial correlation and linear regression models, the contribution from air PAHs to grain PAHs may be greater than that from soil PAHs. Copyright © 2016. Published by Elsevier B.V.

  12. Lead, Zn, and Cd in slags, stream sediments, and soils in an abandoned Zn smelting region, southwest of China, and Pb and S isotopes as source tracers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuangen; Li, Sun; Bi, Xiangyang; Wu, Pan; Liu, Taozhe; Li, Feili; Liu, Congqiang [Chinese Academy of Sciences, Guiyang City (China). Inst. of Geochemistry

    2010-12-15

    Smelting activity produced tons of slags with large quantities of highly toxic metals, resulting in contamination in adjacent soils and sediments as well. This study investigated the fractionation and sources of metals Pb, Zn, and Cd in polluted soils and sediments in a region with once prosperous Zn smelting activities in southwestern China. Soils with varying land uses were of a special concern due to their connection to the food chain. Obtained data would offer a valuable reference to the development of land-use management strategy in this region. In total, 130 soils and 22 stream sediments were sampled in the studied region. After air-dried and passed through a 2 mm sieve, soils and sediments were subjected to a three-step sequential extraction for the fractionation of Pb, Zn, and Cd. Besides, 66 slags were sampled, and acid-digested for the determination of total Pb, Zn, and Cd. Soils/sediments with extremely high Pb, Zn, and Cd concentrations were selected for observation and analysis using a scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. Stable lead and sulphur isotope techniques were applied for source tracing of metals in soils and sediments. Data were pooled for analysis of variance together with a post-hoc multiple comparison procedure. High concentrations of Pb ({proportional_to}46,219 mg kg{sup -1} with medians of 846 mg kg{sup -1} in soil, 7,415 mg kg{sup -1} in sediment, and 8,543 mg kg{sup -1} in slag), Zn ({proportional_to}57, 178 mg kg{sup -1} with medians of 1,085 mg kg{sup -1} in soil, 15,678 mg kg{sup -1} in sediment, and 14,548 mg kg{sup -1} in slag), and Cd ({proportional_to}312 mg kg{sup -1} with medians of 29.6 mg kg{sup -1} in soil, 47.1 mg kg{sup -1} in sediment, and 47.9 mg kg{sup -1} in slag) were measured. Soils with no cultivation had greater concentrations of Pb (16,686 mg kg{sup -1} in median), Zn (13,587 mg kg{sup -1} in median), and Cd (44.1 mg kg{sup -1} in median) than those with cultivation. Al

  13. The use of lichens in post-smelting dumps reclamation - preliminary results of experimental cultivation of selected species on slag substrate

    Science.gov (United States)

    Rola, Kaja; Osyczka, Piotr

    2017-11-01

    Conventional reclamation interventions of post-smelting slag dumps being undertaken so far either failed or produced poor results. Certain lichens, especially of the genus Cladonia, are known as effective colonisers of bare ground in anthropogenic habitats. The paper presents preliminary results of the experiment aimed at the evaluation of lichen usefulness in reclamation interventions. The cultivation in vivo involving transplantation of lichens directly on slag substrate was established in 2015. Five species, i.e. Cladonia rei, C. cariosa, C. pyxidata, C. subulata, C. macilenta, were transplanted into 32 cuvettes filled with sterilised slag substrate. The sample weight of 2 and 6 g were used and half of cuvettes were regularly supplied with 2% malt solution. The first important symptoms at the present stage of the experiment are as follow: the growth of thalli has appeared only in the case of first three species; C. rei shows the most effective development; cuvettes with 6 g sample weight are characterized by higher coverage of fresh lichen thalli; lichen biomass are visually higher in cuvettes treated with malt solution. The results give us reason to believe that lichens could be successfully used as an alternative element during planning of slag dumps reclamation in the future.

  14. Lead Contamination and Source Characterization in Soils Around a Lead-Zinc Smelting Plant in a Near-Urban Environment in Baoji, China.

    Science.gov (United States)

    Deng, Wenbo; Li, Xuxiang; An, Zhisheng; Yang, Liu

    2016-11-01

    Economic reforms in China since 1978 have promoted nationwide socioeconomic advancement but led to a considerable amount of environmental pollution. The distribution and sources of Pb in a typical peri-urban industrial part of Baoji, China, were assessed by determining the Pb contents and isotopic compositions in 52 topsoil samples from the study area. The topsoil samples were polluted averagely with 40.88 mg Pb kg -1 , was 1.86 times higher than the Pb content of local background soil (22.04 mg kg -1 ). Pb isotopic compositions were determined by analyzing samples prepared using total digestion and acid extraction methods. Radiogenic isotopes contributed more to the Pb concentrations in the acid extracts than in the total digests. This was shown by the 207/206 Pb and 208/206 Pb ratios, which were 0.845-0.88 and 2.088-2.128, respectively, in the acid extracts and 0.841-0.875 and 2.086-2.125, respectively, in the total digests. This indicates that anthropogenic sources of Pb could be identified more sensitively in acid extracts than in total digests. The Pb isotope ratios showed that burning coal and smelting ore are the predominant anthropogenic sources of Pb in the study area, i.e., a lead-zinc smelter and a coking plant are major sources of Pb in the study area.

  15. The use of lichens in post-smelting dumps reclamation – preliminary results of experimental cultivation of selected species on slag substrate

    Directory of Open Access Journals (Sweden)

    Rola Kaja

    2017-01-01

    Full Text Available Conventional reclamation interventions of post-smelting slag dumps being undertaken so far either failed or produced poor results. Certain lichens, especially of the genus Cladonia, are known as effective colonisers of bare ground in anthropogenic habitats. The paper presents preliminary results of the experiment aimed at the evaluation of lichen usefulness in reclamation interventions. The cultivation in vivo involving transplantation of lichens directly on slag substrate was established in 2015. Five species, i.e. Cladonia rei, C. cariosa, C. pyxidata, C. subulata, C. macilenta, were transplanted into 32 cuvettes filled with sterilised slag substrate. The sample weight of 2 and 6 g were used and half of cuvettes were regularly supplied with 2% malt solution. The first important symptoms at the present stage of the experiment are as follow: the growth of thalli has appeared only in the case of first three species; C. rei shows the most effective development; cuvettes with 6 g sample weight are characterized by higher coverage of fresh lichen thalli; lichen biomass are visually higher in cuvettes treated with malt solution. The results give us reason to believe that lichens could be successfully used as an alternative element during planning of slag dumps reclamation in the future.

  16. Great Lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2013

    Science.gov (United States)

    Gorman, Owen T.; Weidel, Brian C.

    2014-01-01

    The assessment of Great Lakes prey fish stocks have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique, population indices were standardized to the highest value for a time series within each lake for the following prey species: Cisco (Coregonus artedi), Bloater (C. hoyi), Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Round Goby (Neogobius melanostomus). In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. There was basin-wide agreement in the trends of age-1 and older biomass for all prey species, with the highest concordance occurring for coregonids and Rainbow Smelt, and weaker concordance for Alewife. For coregonids, the highest biomass occurred from the mid-1980s to the mid-1990s. Rainbow Smelt biomass declined slowly and erratically during the last quarter century. Alewife biomass was generally higher from the early 1980s through 1990s across the Great Lakes, but since the early 1990s, trends have been divergent across the lakes, though there has been a downward trend in all lakes since 2005. Recently, Lake Huron has shown resurgence in biomass of Bloater, achieving 75% of its maximum record in 2012 due to recruitment of a succession of strong and moderate year classes that appeared in 2005-2011. Also, strong recruitment of the 2010 year class of Alewife has led to a sharp increase in biomass of Alewife in

  17. Prospects of utilization of electron beam irradiation technology to augment control of SO2 and other emissions from Chilean copper smelting plants

    International Nuclear Information System (INIS)

    Villanueva, L.; Ahumada, L.; Ellison, W.; Chmielewski, A.G.; Zimek, Z.

    1998-01-01

    Analysis of potential utilization of applicable SO 2 -removal process for reduced-SO 2 -strength off-gases, including electron-beam irradiation, for incrementally improving overall abatement of SO 2 /SO 3 emissions from existing copper smelting facilities in Chile has been carried out. Off-gases are characterized by SO 2 content higher than 3,000 ppm, a complex chemical composition and highly oxidizing conditions, along with cyclical and fluctuating generation, reflecting relatively severe service. Laboratory tests with simulated high-SO 2 -strength process gas were performed at Polish Institute of Nuclear Chemistry and Technology. Test work proved the technical feasibility of removing SO 2 from ultra-high SO 2 content smelter gases by E-beam irradiation with ammonia injection. A laboratory unit with flow rate of 20 Nm 3 /h equipped with electron accelerator of 800 keV beam energy was used. Influence of different parameters on SO 2 removal efficiency, like temperature, dose, ammonia stoichiometry and water vapor content, has been established. Tests covered a high SO 2 content range, 2,000 to 10,000 ppm. A generic design has been deviced to address system arrangement, performance and control requirements. It encompasses upgrading of in-plant ventilation to the extent required by health standards, together with gas cleaning system based on EB Process. The arrangement of the facilities provides for gathering and treating off-gas from selected fugitive emission sources on a continuous basis, at the same time in-drafting a minimum amount of tramp air. An introductory dry dedusting stage uses activated coke injection in conjunction with a fabric filter to efficiently treat raw gas to remove heavy metals, including arsenic, along with particulate matter. Main conclusion of the two major stages of this work, i.e. experimental tests and engineering oriented studies, is that the EB Process is a simple and appropriate, cost-effective, chemical process that would, on a site

  18. Prospects of utilization of EB irradiation technology to augment control of SO2 and other emissions from Chilean copper smelting plants

    International Nuclear Information System (INIS)

    Villanueva, L.; Ahumada, L.; Ellison, W.; Chmielewski, A.G.; Zimek, Z.

    1997-01-01

    A technical study including testing and cost analysis for commercial use of selected processes has been conducted. Analysis, affirmation and evaluation of potential utilization of applicable SO 2 -removal process for off-gases, including electron-beam irradiation, for incrementally improving abatement of SO 2 /SO 3 emissions from existing copper smelting facilities in Chile has been carried out. Off-gases are characterized by SO 2 content higher than 3,000 ppm, a complex chemical composition and highly oxidizing conditions, along with cyclical and fluctuating generation. Laboratory tests with simulated high-SO 2 -content process were performed at Institute of Nuclear Chemistry and Technology. Test work proved the technical feasibility of removing SO 2 from (ultra-high SO 2 contents) gases by E-beam irradiation with ammonia injection. A laboratory unit with flow rate of 20 Nm 3 /h equiped with electron accelerator of 800 keV beam energy was used. Influence of different parameters on SO 2 removal efficiency, like temperature, irradiation dose, ammonia stoichiometry and water vapor content, has been established. Tests covered a high SO 2 content range, 2,000 to 10,000 ppm. A generic schematic design has been devised to system arrangement, performance and control requirements. It encompasses upgrading of in-plant ventilation to the extent required by health standards, together with gas cleaning system incorporating the EB Process. The arrangement of the facilities provides for gathering and treating off-gas from selected fugitive emission sources on a continuos basis, at the same time in-drafting a minimum amount of tramp air. An introductory dry dedusting stage, when required, uses condictioned activated carbon injection in conjunction with a fabric filter to efficiently treat raw gas and remove heavy metals, including arsenic, along with particulate matter. Main conclusion of stages of this work is that the EB Process is a simple and appropriate, cost

  19. Acidic leaching of potentially toxic metals cadmium, cobalt, chromium, copper, nickel, lead, and zinc from two Zn smelting slag materials incubated in an acidic soil.

    Science.gov (United States)

    Liu, Taoze; Li, Feili; Jin, Zhisheng; Yang, Yuangen

    2018-07-01

    A column leaching study, coupled with acid deposition simulation, was conducted to investigate the leaching of potentially toxic metals (PTM) from zinc smelting slag materials (SSM) after being incubated in an acid Alfisol for 120 days at room temperature. Two SSMs (SSM-A: acidic, 10 yrs exposure with moderate high PTM concentrations versus SSM-B: alkaline, 2 yrs exposure with extremely high PTM concentrations), were used for the incubation at 0.5, 1, 2.5, 5 wt% amendment ratios in triplicate. Five leaching events were conducted at day 1, 3, 7, 14, and 28, and the leaching of PTMs mainly occurred in the first three leaching events, with the highest PTM concentrations in leachate measured from 5 wt% SSM amendments. After leaching, 2.5, 12, 5.5, 14, 11, and 9 wt% of M3 extractable Pb, Zn, Cd, Co, Cr, and Ni could be released from 5 wt% SSM-A amended soils, being respectively 25, 12, 4, 2, 2, and 2 times more than those from 5 wt% SSM-B amended soils. In the leachates, the concentrations of PTMs were mostly affected by leachant pH and were closely correlated to the concentrations of Fe, Al, Ca, Mg and P with Cd, Pb, and Zn showing the most environmental concern. Visual MINTEQ 3.1 modeling suggested metallic ions and sulfate forms as the common chemical species of PTMs in the leachates; whereas, organic bound species showed importance for Cd, Pb, Cu, and Ni, and CdCl + was observed for Cd. Aluminum hydroxy, phosphate, and sulfate minerals prevailed as the saturated minerals, followed by chloropyromorphite (Pb 5 (PO 4 ) 3 Cl) and plumbogummite (PbAl 3 (PO 4 ) 2 (OH) 5 ·H 2 O) in the leachates. This study suggested that incubation of SSMs in acidic soil for a long term can enhance the release of PTMs as the forms of metallic ions and sulfate when subjected to acid deposition leaching. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Opportunities for energy conservation detected in a diagnosis made for the smelting industry; Oportunidades de ahorro de energia detectadas en un diagnostico efectuado en la industria de la fundicion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Bautista, Rolando; Magana Castro, Rogelio [Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE), Mexico, D. F. (Mexico)

    1994-12-31

    The smelting industry is one of the main industrial branches in the utilization of electric power at national level, for this reason an energy diagnosis was made in representative industries of this process in which excellent results were obtained regarding opportunity areas, with potentials ranging from 15% up to 40% of energy saving in relation to the energy consumption, with actions recoverable in less than 15 months. [Espanol] La industria de la fundicion es una de las principales ramas industriales en la utilizacion de la energia electrica a nivel nacional, por esta razon se realizo un diagnostico energetico en empresas representativas de este proceso y en las cuales se obtuvieron excelentes resultados en cuanto a areas de oportunidad, teniendo potenciales que van desde un 15% hasta un 40% de ahorro con relacion al consumo de energia, con medidas que se recuperan en menos de 15 meses.

  1. Opportunities for energy conservation detected in a diagnosis made for the smelting industry; Oportunidades de ahorro de energia detectadas en un diagnostico efectuado en la industria de la fundicion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Bautista, Rolando; Magana Castro, Rogelio [Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE), Mexico, D. F. (Mexico)

    1993-12-31

    The smelting industry is one of the main industrial branches in the utilization of electric power at national level, for this reason an energy diagnosis was made in representative industries of this process in which excellent results were obtained regarding opportunity areas, with potentials ranging from 15% up to 40% of energy saving in relation to the energy consumption, with actions recoverable in less than 15 months. [Espanol] La industria de la fundicion es una de las principales ramas industriales en la utilizacion de la energia electrica a nivel nacional, por esta razon se realizo un diagnostico energetico en empresas representativas de este proceso y en las cuales se obtuvieron excelentes resultados en cuanto a areas de oportunidad, teniendo potenciales que van desde un 15% hasta un 40% de ahorro con relacion al consumo de energia, con medidas que se recuperan en menos de 15 meses.

  2. Antifreeze activity enhancement by site directed mutagenesis on an antifreeze protein from the beetle Rhagium mordax

    DEFF Research Database (Denmark)

    Friis, Dennis Steven; Kristiansen, Erlend; von Solms, Nicolas

    2014-01-01

    The ice binding motifs of insect antifreeze proteins (AFPs) mainly consist of repetitive TxT motifs aligned on a flat face of the protein. However, these motifs often contain non-threonines that disrupt the TxT pattern. We substituted two such disruptive amino acids located in the ice binding fac...

  3. Great Lakes prey fish populations: A cross-basin overview of status and trends in 2008

    Science.gov (United States)

    Gorman, Owen T.; Bunnell, David B.

    2009-01-01

    Assessments of prey fishes in the Great Lakes have been conducted annually since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. Prey fish assessments differ among lakes in the proportion of a lake covered, seasonal timing, bottom trawl gear used, sampling design, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique in one or more important aspects, a direct comparison of prey fish catches among lakes is problematic. All of the assessments, however, produce indices of abundance or biomass that can be standardized to facilitate comparisons of trends among lakes and to illustrate present status of the populations. We present indices of abundance for important prey fishes in the Great Lakes standardized to the highest value for a time series within each lake: cisco (Coregonus artedi), bloater (C. hoyi), rainbow smelt (Osmerus mordax), and alewife (Alosa pseudoharengus). We also provide indices for round goby (Neogobius melanostomus), an invasive fish presently spreading throughout the basin. Our intent is to provide a short, informal report emphasizing data presentation rather than synthesis; for this reason we intentionally avoid use of tables and cited references.For each lake, standardized relative indices for annual biomass and density estimates of important prey fishes were calculated as the fraction relative to the largest value observed in the times series. To determine whether basin-wide trends were apparent for each species, we first ranked standardized index values within each lake. When comparing ranked index values from three or more lakes, we calculated the Kendall coefficient of concordance (W), which can range from 0 (complete discordance or disagreement among trends) to 1 (complete concordance or agreement among trends). The P-value for W provides the probability of agreement across the lakes. When comparing ranked index values from two lakes, we calculated

  4. Fault detection-case: modelling of temperature control of smelt in a chemical recovery; Deteccao de defeitos via redes neurais: aplicacao no sistema de resfriamento das bicas de fundidos de uma caldeira de recuperacao

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, Sergio H.S. [Universidade Estadual de Maringa, PR (Brazil); Klabin Papeis Monte Alegre, Telemaco Borba, PR (Brazil); Neitzel, Ivo [Faculdade de Telemaco Borba, PR (Brazil); Universidade Estadual de Maringa, PR (Brazil); Vieira, Osvaldo [Universidade Estadual de Maringa, PR (Brazil); Klabin Papeis Monte Alegre, Telemaco Borba, PR (Brazil)

    2008-07-01

    This paper proposes a method for the detection of defects in the control systems components which was applied in the smelt spouts cooling system of a chemical recovery boiler. The almost static behavior of the system was modeled with neural networks. The comparison between the inferred variable by the model and the measurement in the process generated a residual vector. A second neural network, the classification type, was built to analyze the residue. The training process of this neural network was carried out with two types of data base, one of them where there was no defect (classified as non faulty data) and the other where there were defects in one of the process control system sensors. The generation of faulty data was carried out through defects simulation by neural model. Both neural networks were programmed on Excel software to make the continuous monitoring of the productive process possible. The process data feeding in the system was done though the Plant Information (PI) software. The rate of false alarm of process monitoring for two and half months was of 3%. Errors ranging from 2 to 15% were simulated at the manipulated variable of the control system to test the performance of the method. Within the range of 10% simulated errors the detection of defects rate was of 97% for the set of non trained standards. (author)

  5. Connectivity between migrating and landlocked populations of a diadromous fish species investigated using otolith microchemistry.

    Directory of Open Access Journals (Sweden)

    Ingrid Tulp

    Full Text Available Smelt Osmerus eperlanus has two different life history strategies in The Netherlands. The migrating population inhabits the Wadden Sea and spawns in freshwater areas. After the closure of the Afsluitdijk in 1932, part of the smelt population became landlocked. The fresh water smelt population has been in severe decline since 1990, and has strongly negatively impacted the numbers of piscivorous water birds relying on smelt as their main prey. The lakes that were formed after the dike closure, IJsselmeer and Markermeer have been assigned as Natura 2000 sites, based on their importance for (among others piscivorous water birds. Because of the declining fresh water smelt population, the question arose whether this population is still supported by the diadromous population. Opportunities for exchange between fresh water and the sea are however limited to discharge sluices. The relationship between the diadromous and landlocked smelt population was analysed by means of otolith microchemistry. Our interpretation of otolith strontium ((88Sr patterns from smelt specimens collected in the fresh water area of Lake IJsselmeer and Markermeer, compared to those collected in the nearby marine environment, is that there is currently no evidence for a substantial contribution from the diadromous population to the spawning stock of the landlocked population.

  6. EFECTO EN LA RESISTENCIA DE LAS ESCORIAS DE FUNDICIÓN DE COBRE COMO AGREGADO FINO EN EL COMPORTAMIENTO RESISTENTE DEL HORMIGÓN EFFECT OF SMELTING COPPER SLAG AS FINE AGGREGATE ON THE RESISTANT BEHAVIOR OF CONCRETE

    Directory of Open Access Journals (Sweden)

    Patricio Cendoya

    2009-04-01

    Full Text Available Las escorias de fundición de cobre son residuos industriales provenientes de la fundición del cobre las cuales procesadas en forma de granallas y sometidas a un proceso de molienda adquieren características similares a las de un árido fino. La presente investigación estudia la influencia que tiene su incorporación en el comportamiento mecánico a flexotracción y compresión en hormigones que emplean como árido fino una combinación de arenas del río Bío-Bío con proporciones de 25%, 40% y 50% en volumen de escorias de fundición de cobre. El árido fino resultante se utiliza en la confección de hormigones dosificados para relaciones de agua cemento de 0,45 y 0,52 asociadas a resistencias especificadas a la flexotracción de 3,6 y 4,3 MPa. Se mide la trabajabilidad en el hormigón fresco, la densidad, la carga de rotura por flexotracción y la carga de rotura por compresión en el hormigón endurecido comparando los resultados con un hormigón de referencia que no contiene escorias. Los resultados señalan que la docilidad de la mezcla se incrementa debido a la textura lisa de las escorias, se produce un aumento de la densidad del hormigón endurecido y las resistencias tanto a flexotracción como compresión se incrementan en función del contenido de escorias de fundición de cobre utilizado en la mezcla.Copper slag is a by product of the copper smelting industry. We took granulated copper slag and milled it until it acquired characteristics similar to those of a fine aggregate, which was then incorporated into concrete, in combination with Bio-Bio river sand in proportions of 25%, 40% and 50% by volume of copper slag. We then examined the impact of the different combinations on the mechanical behaviour to flexotraction and compression in the resulting concrete. Our specification was to produce concrete for water-cement ratios of 0,45 and 0,52 associated to breakage resistances to flexotraction of 3.6 and 4.3 MPa, respectively. We

  7. Review of Liquidus Surface and Phase Equilibria in the TiO2-SiO2-Al2O3-MgO-CaO Slag System at PO2 Applicable in Fluxed Titaniferous Magnetite Smelting

    Science.gov (United States)

    Goso, Xolisa; Nell, Johannes; Petersen, Jochen

    The current liquidus surface and phase equilibria established in air for fluxed titaniferous magnetite (titanomagnetite) slags conforming to a composition of 37.19% TiO2, 19.69% SiO2, 13.12% Al2O3, and 30.00% of various ratios of CaO+MgO were reviewed at applicable PO2 using FactSage simulation and phase composition of a real plant titanomagnetite slag. The testwork included the incorporation into FactSage of a private MgTi2O5-Al2TiO5 pseudobrookite solution model. The results of the investigation showed that the liquidus surface and Ti3+/ Ti4+ mass fraction ratio increased with decreasing the PO2, At low PO2, perovskite crystallizes as a primary phase at high CaO content. The spinel solution, i.e. (Mg)(Al,Ti)O4, generally crystallizes as the primary phase at high MgO contents, though it is replaced by MgTi2O5-Al2TiO5 solution at PO2 of 10-10 atm to 10-15 atm. An intermediate equilibrium phase diagram established at PO2 of 10-16 atm is proposed. This phase diagram does not show the observed primary phase crystallization competition, however, the phase composition of a real titanomagnetite slag produced by Evraz Highveld Steel and Vanadium Corporation in South Africa does show primary phase crystallization competition between (Mg)(Al,Ti)2O4 and MgTi2O5-Al2TiO5. Smelting involving such slags is likely conducted around the transition PO2, i.e. PO2 of about 10-16 atm. Complex modelling with MgTi2O5, Al2TiO5 and Ti3O5 end members and experiments are underway to verify and update the intermediate phase diagram.

  8. Co-treatment of flotation waste, neutralization sludge, and arsenic-containing gypsum sludge from copper smelting: solidification/stabilization of arsenic and heavy metals with minimal cement clinker.

    Science.gov (United States)

    Liu, De-Gang; Min, Xiao-Bo; Ke, Yong; Chai, Li-Yuan; Liang, Yan-Jie; Li, Yuan-Cheng; Yao, Li-Wei; Wang, Zhong-Bing

    2018-03-01

    Flotation waste of copper slag (FWCS), neutralization sludge (NS), and arsenic-containing gypsum sludge (GS), both of which are difficult to dispose of, are major solid wastes produced by the copper smelting. This study focused on the co-treatment of FWCS, NS, and GS for solidification/stabilization of arsenic and heavy metals with minimal cement clinker. Firstly, the preparation parameters of binder composed of FWCS, NS, and cement clinker were optimized to be FWCS dosage of 40%, NS dosage of 10%, cement clinker dosage of 50%, mill time of 1.5 h, and water-to-binder ratio of 0.25. On these conditions, the unconfined compressive strength (UCS) of the binder reached 43.24 MPa after hydration of 28 days. Then, the binder was used to solidify/stabilize the As-containing GS. When the mass ratio of binder-to-GS was 5:5, the UCS of matrix can reach 11.06 MPa after hydration of 28 days, meeting the required UCS level of MU10 brick in China. Moreover, arsenic and other heavy metals in FWCS, NS, and GS were effectively solidified or stabilized. The heavy metal concentrations in leachate were much lower than those in the limits of China standard leaching test (CSLT). Therefore, the matrices were potential to be used as bricks in some constructions. XRD analysis shows that the main hydration products of the matrix were portlandite and calcium silicate hydrate. These hydration products may play a significant role in the stabilization/solidification of arsenic and heavy metals.

  9. Aluminum low temperature smelting cell metal collection

    Science.gov (United States)

    Beck, Theodore R.; Brown, Craig W.

    2002-07-16

    A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte. Molten aluminum is collected from the cathodes into a tubular member positioned underneath the cathodes. The tubular member is in liquid communication with each cathode to collect the molten aluminum therefrom while excluding electrolyte. Molten aluminum is delivered through the tubular member to a molten aluminum reservoir located substantially opposite the anodes and cathodes. The molten aluminum is collected from the cathodes and delivered to the reservoir while avoiding contact of the molten aluminum with the anodic bottom.

  10. Long-term effects of extreme weather events and eutrophication on the fish community of shallow Lake Peipsi (Estonia/Russia

    Directory of Open Access Journals (Sweden)

    Külli Kangur

    2013-06-01

    Full Text Available The fish kill in lake Peipsi (Estonia/Russia during the extraordinarily hot summer of 2010 evoked an investigation into the effects of environmental extremes and long-term eutrophication on the fish community of the lake. Current data on lake Peipsi indicate that temperature extremes and synergistic interactions with eutrophication have led to a radical restructuring of the fish community. Commercial landings of lake smelt, Osmerus eperlanus eperlanus m. spirinchus (Pallas, the previous dominant species of the fish community, have decreased dramatically since the 1930s, these declines being coupled with summer heat waves coinciding with low water levels. Gradual decline in smelt stock and catches was significantly related to a decline of near-bottom oxygen conditions and to a decrease in water transparency. The first documented fish kill in 1959 occurred only in the southern, most shallow and eutrophic lake (lake Pihkva. Recently, summer fish kill have become more frequent, involving larger areas of the lake. In addition to the cold-water species, e.g. smelt and vendace Coregonus albula (L., the abundance of bottom-dwelling fishes such as ruffe Gymnocephalus cernuus (L. and juvenile fish have significantly decreased after the 2010 heat wave probably due to hypoxia and warm water temperatures. This study showed that fish community structure in large shallow lakes may be very vulnerable to water temperature increases, especially temperature extremes in combination with eutrophication.

  11. Testing antifreeze protein from the longhorn beetle Rhagium mordax as a kinetic gas hydrate inhibitor using a high-pressure micro differential scanning calorimeter

    DEFF Research Database (Denmark)

    Daraboina, Nagu; Perfeldt, Christine Malmos; von Solms, Nicolas

    2015-01-01

    Low dosage kinetic hydrate inhibitors are employed as alternatives to expensive thermodynamic inhibitors to manage the risk of hydrate formation inside oil and gas pipelines. These chemicals need to be tested at appropriate conditions in the laboratory before deployment in the field. A high press...

  12. Production of fish finger from sand smelt (Atherina boyeri, RISSO ...

    African Journals Online (AJOL)

    Administrator

    2011-05-23

    May 23, 2011 ... Departmant of Fishing and Fish Processing Technology, Faculty of Fisheries, University of Süleyman Demirel, 32500. Eğirdir, Isparta, Turkey. ... the consumption of food as “heat and eat” has become important. Food sector .... In many of the developed countries, the habits of nourish- ment are changing and ...

  13. State of the direct reduction and reduction smelting processes

    Directory of Open Access Journals (Sweden)

    Markotić A.

    2002-01-01

    Full Text Available For quite a long time efforts have been made to develop processes for producing iron i.e. steel without employing conventional procedures - from ore, coke, blast furnace, iron, electric arc furnace, converter to steel. The insufficient availability and the high price of the coking coals have forced many countries to research and adopt the non-coke-consuming reduction and metal manufacturing processes (non-coke metallurgy, direct reduction, direct processes. This paper represents a survey of the most relevant processes from this domain by the end of 2000, which display a constant increase in the modern process metallurgy.

  14. Chemical-mineralogical characterization of copper smelting flue dust

    Directory of Open Access Journals (Sweden)

    Eduardo Balladares

    2014-01-01

    Full Text Available En el procesamiento pirometalúrgico del cobre, hasta 10% de la carga alimentada a los hornos sale de estos en forma de polvo arrastrado por los gases conteniendo la mayor parte de las impurezas presentes en el mineral, así como cantidades significativas de cobre por lo que no pueden ser descartados como residuos industriales y debe tratarse para recuperar el cobre. La conceptualización de nuevos y mejores procesos requiere caracterizaciones de estos materiales más precisas. Se analizaron polvos provenientes de una caldera recuperadora de calor y de un precipitador electrostático, ambos de un horno de fusión instantánea. Las diferentes herramientas analíticas empleadas muestran que el cobre y el hierro se encuentran principalmente en fases solubles en agua tales como chalcantita. La fracción insoluble está formada mayoritariamente por hematita y magnetita, con probable presencia de delafosita. Parte del cobre detectada en la fracción insoluble se asocia al hierro en forma de espinela.

  15. The aluminum smelting process and innovative alternative technologies.

    Science.gov (United States)

    Kvande, Halvor; Drabløs, Per Arne

    2014-05-01

    The industrial aluminum production process is addressed. The purpose is to give a short but comprehensive description of the electrolysis cell technology, the raw materials used, and the health and safety relevance of the process. This article is based on a study of the extensive chemical and medical literature on primary aluminum production. At present, there are two main technological challenges for the process--to reduce energy consumption and to mitigate greenhouse gas emissions. A future step may be carbon dioxide gas capture and sequestration related to the electric power generation from fossil sources. Workers' health and safety have now become an integrated part of the aluminum business. Work-related injuries and illnesses are preventable, and the ultimate goal to eliminate accidents with lost-time injuries may hopefully be approached in the future.

  16. Changes on the nutritional compositions of the sand smelt (Atherina ...

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... ash and fat content and a decrease (P<0.05) in protein and moisture content were determined. In fatty .... cies as well as to present it to the market as an alternative food. ... in the glass jars again and sunflower oil was added (1:1 w/v). ... Determination of the fatty acid was performed by the use of gas.

  17. Electrolytic smelting of lunar rock for oxygen, iron, and silicon

    Science.gov (United States)

    Haskin, Larry A.; Colson, Russell O.; Lindstrom, David J.; Lewis, Robert H.; Semkow, Krystyna W.

    1992-01-01

    Preliminary studies of the electrochemical properties of silicate melts such as those available from heating of lunar mare soils indicate that conductivities are high enough for design of a practical electrolytic cell. The nature and kinetics of the electrode reactions, which involve reduction of Fe(++) and Si(IV) and oxidation of silicate anions as the primary, product-forming reactions, are also satisfactory. A survey of the efficiencies for production (amount of product for a given current) of O2, Fe(sup 0), and Si(sup 0) as functions of potential and of electrolyte composition indicate that conditions can be chosen to yield high production efficiencies. We also conclude that electronic conductivity does not occur to a significant extent. Based on these data, a cell with electrodes of 30 sq m in area operating between 1 and 5V with a current between 1.6 and 3.5(10)(exp 5) A for a mean power requirement of 0.54 MW and total energy use of approximately 13 MWhr per 24-hr day would produce 1 ton of O2, 0.81 ton of Fe(sup 0), 0.65 ton of Si(sup 0) (as Fe(sup 0)-Si(sup 0) alloy), and about 3.5 tons of silicate melt of altered composition per 24 hr. Adjustable distance between electrodes could offer flexibility with respect to feedstock and power source.

  18. The Aluminum Smelting Process and Innovative Alternative Technologies

    Science.gov (United States)

    Drabløs, Per Arne

    2014-01-01

    Objective: The industrial aluminum production process is addressed. The purpose is to give a short but comprehensive description of the electrolysis cell technology, the raw materials used, and the health and safety relevance of the process. Methods: This article is based on a study of the extensive chemical and medical literature on primary aluminum production. Results: At present, there are two main technological challenges for the process—to reduce energy consumption and to mitigate greenhouse gas emissions. A future step may be carbon dioxide gas capture and sequestration related to the electric power generation from fossil sources. Conclusions: Workers' health and safety have now become an integrated part of the aluminum business. Work-related injuries and illnesses are preventable, and the ultimate goal to eliminate accidents with lost-time injuries may hopefully be approached in the future. PMID:24806723

  19. Ecotoxicological damage from zinc smelting at Palmerton, Pennsylvania

    Science.gov (United States)

    Beyer, W. Nelson; Storm, Gerald L.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

    1995-01-01

    The two zinc smelters at Palmerton, PA emitted huge amounts of contaminants ( 260,000 t of Zn, 3,300 t of Cd, 6,800 t of Pb) to the air and severely damaged the forest on Blue Mountain. The high Zn concentrations in soil killed tree seedlings by inhibiting root elongation. The result was a forest with too few young trees. When natural stresses such as fire challenged the forest, the forest failed to regenerate, and the exposed soil eroded down the steep slopes. Tree species that could sprout were favored over those that developed from seeds. As a result of high zinc concentrations, the lichen and moss communities were depauperate for at least 20 km along Blue Mountain. The denuded areas are in the process of being reclaimed with the addition of a mixture of fly ash and sewage sludge, which is seeded with grasses tolerant to the harsh conditions. In preliminary experiments, the fly ash and sewage sludge mixture was stable, despite the steepness of the slopes of the reclaimed sites on Blue Mountain. Zinc emissions reduced the decomposition rate of plant material on Blue Mountain. The partially decomposed litter, in particular, accumulated on the surface of the mineral soil. The populations of both microorganisms and arthropods were greatly reduced in soils near the smelters. Samples of litter collected from sites spanning 30 km were toxic to woodlice, and Zn was shown to be the toxic factor. A white-tailed deer examined had a very high renal Zn concentration and an articular lesion in one of its hind legs that closely resembled the lesions reported in Zn-poisoned horses. Zinc concentrations were regulated in wildlife tissues and were not reliable indicators of exposure, except in extreme cases. Two songbirds, a shrew, and several rabbits contained Pb concentrations that were suggested to be toxic. Shrews and ground-feeding songbirds accumulated relatively high concentrations of Pb. Exposure to Pb seemed to be related to the amount of soil that an animal ingests. Some white-tailed deer and cottontails had renal Cd concentrations near 600 ppm w.w., which is associated with renal damage in other mammals. The accumulation of Cd was greatest in wildlife that lived longest. The destruction of the habitat for wildlife on Blue Mountain decreased wildlife populations. Populations of insectivorous birds, however, were depressed well beyond the area of obvious damage to the forest. Forest-floor salamanders were completely absent from study sites spanning 18 km along Blue Mountain. Actual reductions in wildlife populations were much greater than would have been predicted from habitat suitability models alone.

  20. Nursery use of shallow habitats by epibenthic fishes in Maine nearshore waters

    Science.gov (United States)

    Lazzari, M. A.; Sherman, S.; Kanwit, J. K.

    2003-01-01

    Species richness and abundance of epibenthic fishes were quantified with daytime beam trawl tows in shallow water habitats during April-November 2000 of three mid-coast Maine estuaries: Casco Bay, Muscongus Bay and the Weskeag River. Five shallow (Gasterosteus aculeatus, Apeltes quadracus, Pungitius pungitius, Myoxocephalus aenaeus, and Cylcopterus lumpus. The fish community of mid-coast estuaries was dominated by young-of-the-year (YOY) and juvenile fishes and all of the habitat types function as nursery areas. Twelve species (38%) of commercial and recreational importance were collected in the three estuaries, but the percentage was higher in Casco Bay (44%) and the Weskeag River (46%). These species included Anguilla rostrata, Clupea harengus, Gadus morhua, Microgadus tomcod, Pollachius virens, Urophycis chuss, Urophycis regia, Urophycis tenuis, Osmerus mordax, Macrozoarces americanus, Tautogolabrus adspersus, and Pleuronectes americanus. Four species, G. morhua, M. tomcod, P. virens, and U. tenuis were more common in spring than summer or autumn. P. americanus was most abundant in summer followed by spring and autumn. This study documents the importance of shallow estuarine areas in Maine as nurseries for these species.

  1. Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

    Directory of Open Access Journals (Sweden)

    Tom Robin Olk

    2016-11-01

    Full Text Available This study is based on monthly sampling of fish from grates mounted at an industrial water intake, located at a depth of 50 m in Lake Norsjø (Southern Norway during the year 2014, to investigate seasonal variations in the use of the profundal habitat and subsequent variations in total Hg-concentrations in profundal fish. Data on various fish present in a cold and dark hypolimnion of a large, deep, dimictic lake within the upper temperate zone of the Northern Hemisphere are rare. While predominant species such as A. charr (Salvelinus alpinus and E. smelt (Osmerus eperlanus were continuously present in this habitat, whitefish (Coregonus lavaretus occupied this habitat primarily during wintertime, while other common species like brown trout (Salmo trutta, perch (Perca fluviatilis and northern pike (Esox lucius were almost absent. Besides stomach analyses (diet and biometry, stable isotope analyses (δ15N and δ13C and total mercury (Tot-Hg analyses were carried out on the caught fish. The δ13C signature and stomach analyses revealed a combined profundal-pelagic diet for all three species, A. charr with the most profundal-based diet. Length was the strongest predictor for Hg in whitefish and A. charr, while age was the strongest explanatory variable for Hg in E. smelt. A. charr was the only species exhibiting seasonal variation in Hg, highest during winter and spring.

  2. Food web accumulation of cyclic siloxanes in Lake Mjøsa, Norway.

    Science.gov (United States)

    Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S

    2012-06-05

    The biomagnification of the cyclic volatile methyl siloxanes octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexatetrasiloxane (D6) was analyzed in the Lake Mjøsa food web in Norway from zooplankton and Mysis to planktivorous and piscivorous fish. The trophic magnification factor (TMF) for D5 was determined and compared with TMFs of several legacy contaminants: polychlorinated biphenyl (PCB) congeners 153 and 180, polybrominated diphenyl ether (PBDE) congeners 47 and 99, and p,p'-DDE. D5 showed TMF significantly greater than 1, implying food web biomagnification (TMF = 2.28, CI: 1.22-4.29). This contrasts with two studies that reported TMF < 1, which may reflect variability in TMF between food webs. The Lake Mjøsa D5 TMF was sensitive to the species included at the higher trophic level; whole food web TMF differed from TMF excluding smelt (Osmerus eperlanus) or brown trout (Salmo trutta) (TMF(-SMELT) = 1.62, CI: 0.96-2.72; TMF(-TROUT) = 3.58, CI: 1.82-7.03). For legacy contaminants (e.g., PCB-153 and PCB-180), the TMFs were less sensitive to the food web composition, and a better model fit was obtained compared to D5. The differences in biomagnification behavior between D5 and the legacy contaminants suggest that the biomagnification of D5 is being governed by species-specific properties such as biotransformation rate or tissue distribution that differ from those of legacy contaminants.

  3. FY 2000 report on the research cooperation project 'research cooperation diagnosis survey.' Research cooperation in technology to improve the environmental response type industrial use water circulation utilization (Thailand) Nos. 1 and 2. and research cooperation in technology to recover the harmless metal in smoke/ash in smelting works (Chile); 2000 nendo kenkyu kyoryoku jigyo 'kenkyu kyoryoku shindan chosa' hokokusho. Kankyo taiogata kogyoyosui junkan riyo kojo gijutsu ni kansuru kenkyu kyoryoku (Tai) 1 kaime 2 kaime, seirenjo enbai no mugaika kinzoku kaishu gijutsu ni kansuru kenkyu kyoryoku (Chiri)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In Chile, for the purpose of coping with problems on the ground subsidence and water shortage caused by pumping up the industrial use ground water, survey was conducted of the research cooperation in reutilization of the industrial waste water retreated for the food industry and the fiber industry. As a result, as a MOU plan, the establishment of the regenerative utilization technology was proposed of the treated water after the activated sludge treatment in food plants and after the Lagoon treatment in the fiber/dyeing industry. In Chile, relating to the harmless metal recovery technology to recover valuable metals such as copper, lead, zinc and silver included in the smoke/ash containing arsenic in copper smelting works at low cost by reducing environmental loads, conducted were survey for research cooperation and discussion on the making of a draft of the basic agreement. The project includes the high grade leaching separation, simplification/non-slagging of the lead/silver residue melting process, optimization of the copper separation/recovery method, fixation/weight-reduction of the leached arsenic, optimization of the zinc recovery method, optimization of the final waste water treating process, study of the design/construction/operation of the pilot plant, etc. (NEDO)

  4. FY 2000 report on the research cooperation project 'research cooperation diagnosis survey.' Research cooperation in technology to improve the environmental response type industrial use water circulation utilization (Thailand) Nos. 1 and 2. and research cooperation in technology to recover the harmless metal in smoke/ash in smelting works (Chile); 2000 nendo kenkyu kyoryoku jigyo 'kenkyu kyoryoku shindan chosa' hokokusho. Kankyo taiogata kogyoyosui junkan riyo kojo gijutsu ni kansuru kenkyu kyoryoku (Tai) 1 kaime 2 kaime, seirenjo enbai no mugaika kinzoku kaishu gijutsu ni kansuru kenkyu kyoryoku (Chiri)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In Chile, for the purpose of coping with problems on the ground subsidence and water shortage caused by pumping up the industrial use ground water, survey was conducted of the research cooperation in reutilization of the industrial waste water retreated for the food industry and the fiber industry. As a result, as a MOU plan, the establishment of the regenerative utilization technology was proposed of the treated water after the activated sludge treatment in food plants and after the Lagoon treatment in the fiber/dyeing industry. In Chile, relating to the harmless metal recovery technology to recover valuable metals such as copper, lead, zinc and silver included in the smoke/ash containing arsenic in copper smelting works at low cost by reducing environmental loads, conducted were survey for research cooperation and discussion on the making of a draft of the basic agreement. The project includes the high grade leaching separation, simplification/non-slagging of the lead/silver residue melting process, optimization of the copper separation/recovery method, fixation/weight-reduction of the leached arsenic, optimization of the zinc recovery method, optimization of the final waste water treating process, study of the design/construction/operation of the pilot plant, etc. (NEDO)

  5. The Fish Assemblage of a Newfoundland Estuary: Diel, Monthly and Annual Variation

    Science.gov (United States)

    Methven, D. A.; Haedrich, R. L.; Rose, G. A.

    2001-06-01

    Twice monthly sampling over two 16 month periods at a shallow site on Newfoundland's east coast showed the fish assemblage to be dominated by four taxa ( Gasterosteus aculeatus, G. wheatlandi, Osmerus mordax, Gadus spp.) that accounted for 96% of the individuals collected. Of the 16 479 fish measured, 65% were adults based on the estimated size of first spawning. The fish assemblage was dominated (86%) by species with demersal eggs, several of which spawn at the same shallow sites used by juveniles as nursery sites. Coastal spawning and demersal eggs maintain offspring in coastal nursery areas where survival is thought to be increased. Number of species and number of fish were both correlated with water temperature being highest from mid-summer to early autumn and lowest in winter. Temperature, time of spawning, and movements of juveniles and adults facilitated grouping species into five assemblages based on seasonal abundance: seasonal periodic species (summer and winter), regular species, regular species collected in all seasons except winter, and occasional (rare) species. At the diel scale, two consistent species groupings were observed: species that showed no significant difference between day and night and species caught primarily at night. Number of night species exceeded day species by a factor of two. No seine-caught species in shallow water exhibited significantly higher catches during the day. Observations by SCUBA divers indicated some species were more abundant during day time at slightly deeper depths. This observation in conjunction with day and night seining in shallower water, suggests these species aggregate in deeper water during day and move to shallow waters at night.

  6. 76 FR 38591 - National Emission Standards for Hazardous Air Pollutants: Secondary Lead Smelting; Extension of...

    Science.gov (United States)

    2011-07-01

    ... in the public docket and made available on the Internet. If you submit an electronic comment, the EPA... contact you for clarification, the EPA may not be able to consider your comment. Electronic files should...: Questions concerning the proposed rule should be addressed to Mr. Chuck French, Office of Air Quality...

  7. Outdoor and indoor cadmium distributions near an abandoned smelting works and their relations to human exposure

    International Nuclear Information System (INIS)

    Spurgeon, David J.; Lawlor, Alan; Hooper, Helen L.; Wadsworth, Richard; Svendsen, Claus; Thomas, Laura D.K.; Ellis, James K.; Bundy, Jacob G.; Keun, Hector C.; Jarup, Lars

    2011-01-01

    The relationship of measured or modelled Cd concentrations in soil, house dust and available to plants with human urinary Cd concentrations were assessed in a population living around a Cd/Pb/Zn smelter in the UK. Modelled air concentrations explained 35% of soil Cd variation indicating the smelter contributed to soil Cd loads. Multi-variate analysis confirmed a significant role of biological and life-style factors in determining urinary Cd levels. Significant correlations of urinary Cd with soil, house dust and modelled plant available Cd concentrations were not, however, found. Potential reasons for the absence of clear relationships include limited environmental contact in urban populations; the role of undefined factors in determining exposure; and the limited spatial scope of the survey which did not sample from the full pollution gradient. Further, the absence of any significant relationship indicates that environmental measures provide limited advantage over atmospheric model outputs for first stage human exposure assessment. - Highlights: → Environmental measurements indicate smelter pollution of a surrounding urban area. → Life-style and biology influenced U-Cd more than measured environmental levels. → Limited contact with outdoor environments may limit Cd uptake in urban populations. → Better life-style data could improve the attribution of human Cd exposure routes. → Measured Cd levels provide limited added exposure insight over dispersion models. - Measured and modelled environmental cadmium concentrations provide limited additional explanation of human urinary cadmium concentrations.

  8. Cancer incidence among copper smelting and nickel refining workers in Finland.

    Science.gov (United States)

    Pavela, Markku; Uitti, Jukka; Pukkala, Eero

    2017-01-01

    Among workers employed at a nickel refinery in Harjavalta, Finland an increased risk of lung and sinus cancer has been demonstrated in two previous studies. The current study adds 16 more years of follow-up to these studies. A total of 1,115 persons exposed to nickel and 194 non-exposed workers in the Harjavalta nickel smelter and refinery were followed up for cancer from 1967 to 2011 through the Finnish Cancer Registry. The total number of cancer cases in men was 251 (Standardized incidence ratio (SIR) 1.05) and in women 12 (SIR 1.22). In the most nickel-exposed work site (refinery), there were 14 lung cancers (SIR 2.01) and 3 sinonasal cancers (SIR 26.7, 95%). It is likely that exposure to nickel compounds is the main reason for elevated nasal cancer risk among the nickel refinery employees and may also contribute to the excess risk of lung cancer. Am. J. Ind. Med. 60:87-95, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. 76 FR 14636 - National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting

    Science.gov (United States)

    2011-03-17

    ... 15 days to April 19, 2011. The EPA received a request for this extension from the Doe Run Company, the sole covered facility. Doe Run Company requested the extension in order to analyze data and review..., the public comment period will now end on April 19, 2011. How can I get copies of the proposed rule...

  10. Options report for the mining, non-ferrous metal smelting and refining industry

    International Nuclear Information System (INIS)

    1999-10-01

    This plant level analysis involved the study of three Canadian mines from ore extraction to refining. Energy consumption and GHG emissions from each facility were examined, along with projects to reduce these emissions. Results showed variation in emissions between firms by orders of magnitude, and while GHG reducing projects do exist, many are not implemented for economic and business reasons. Nevertheless, a modelling analysis of the mining industry as a whole showed that the industry should be able to reduce its GH emissions to within range of the Kyoto target. Enhanced voluntary initiatives, already supported by the industry, are seen as the most cost effective means of achieving these emission reductions. Industry experts suggest more effort to be expended on identifying GHG reducing technologies and competing projects with higher returns on investment. There is incontrovertible evidence that energy efficiency measures are often not implemented by the industry because their return on investment are not as attractive as those associated with process improvement projects. With appropriate assistance from government, such as funding for comprehensive energy audits similar to the plant level analysis done for this report, funding for carrying out the detailed economic evaluation of these projects, help with specialized human resources to participate in enhanced voluntary activities (such as the energy audits and life cycle cost/benefit analysis), and financial incentives to create more attractive returns on investment for energy efficiency/GHG emission reduction projects, the Canadian mining industry will be, and can be, part of the solution towards reducing GHG emissions. Other avenues that could be helpful in this effort include exporting Canadian mining technology to aid in reaching a global solution to a global problem, recognition for the Canadian mining industry for its northern operations, credit for Canada for embodied energy in exports, and recycling to extend the efficient use of metals. 7 tabs., 1 fig

  11. 19 CFR 19.18 - Smelting and refining; allowance for wastage; withdrawal for consumption.

    Science.gov (United States)

    2010-04-01

    ...; withdrawal for consumption. 19.18 Section 19.18 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT... wastage; withdrawal for consumption. (a) Except where absolute deductions have been allowed in the... entered for consumption or for warehouse, during a 12-month period beginning on the first day of the month...

  12. Smelting crucibles to reduce copper minerals in the Iberian Peninsula and in southern France

    Directory of Open Access Journals (Sweden)

    Rovira, Salvador

    2002-06-01

    Full Text Available As was shown in Spain by the end of the 1980s, the use of common earthenware vessels as containers for prehistoric copper metallurgy has also been discovered in France. The authors propose in this article a synthesis of the knowledge concerning the use of this technology in Spain, its chronological and geographical frameworks and the more relevant mineralogical and metallurgical features. All this allows us to show the effectiveness and simplicity of the resources used to practice this early metallurgy. The finds in France are more modest and rarely have been analysed properly in the laboratory. However, the review of the archaeological record suggests that specific research informed by the results presented in the article would provide evidence of the impact of this technology through the Copper and Bronze Ages.

    [es] Puesta en evidencia en España a finales de la década de los ochenta, la utilización de vasijas de cerámica común como recipiente de la metalurgia del cobre prehistórico ha sido identificada también en Francia. Los autores proponen una síntesis del estado de los conocimientos sobre el uso de esta técnica en España, su encuadre geográfico y cronológico y sus principales características mineralógicas y metalúrgicas. Estas últimas permiten mostrar la eficacia y la simplicidad de los medios puestos en juego para la realización de esta metalurgia inicial. En contrapartida, en Francia los hallazgos son todavía modestos y sólo unos pocos han sido objeto de los apropiados análisis de laboratorio. No obstante, la revisión de la documentación arqueológica sugiere que investigaciones específicas orientadas por los resultados expuestos en este artículo deberían permitir en Francia, como ha sucedido en España en el curso de los últimos años, poner de manifiesto el impacto de esta técnica durante las Edades del Cobre y del Bronce. [fr] Les céramiques à réduire le minerai de cuivre dans la Péninsule Ibérique et en France méridionale. Mise en évidence en Espagne à la fin des années quatre-vingts, l´utilisation de céramiques banales comme récipient de la métallurgie du cuivre préhistorique a été désormais repérée en France. Dans cet article, les auteurs proposent une synthèse de l'état des connaissances concernant l'utilisation de cette technique en Espagne, son cadre géographique et chronologique, ses principales caractéristiques minéralogiques et métallurgiques. Elles permettent de montrer V efficacité et la simplicité des moyens mis enjeu dans la réalisation de cette métallurgie précoce. En France, les données restent en contrepartie modestes, et n’ont fait que rarement encore l´objet d'analyses de laboratoire ad hoc. Néanmoins, la recension des documents archéologiques suggère qu’une recherche spécifique, éclairée par les résultats exposés dans cet article, devrait permettre en France, comme ce fût le cas en Espagne au cours des dernières années, de montrer l'impact de cette technique au cours des âges du Cuivre et du Bronze.

  13. Phytotoxicity of zinc and manganese to seedlings grown in soil contaminated by zinc smelting

    Science.gov (United States)

    Beyer, W.N.; Green, C.E.; Beyer, M.; Chaney, R.L.

    2013-01-01

    Historic emissions from two zinc smelters have injured the forest on Blue Mountain near Palmerton, Pennsylvania, USA. Seedlings of soybeans and five tree species were grown in a greenhouse in a series of mixtures of smelter-contaminated and reference soils and then phytotoxic thresholds were calculated. As little as 10% Palmerton soil mixed with reference soil killed or greatly stunted seedlings of most species. Zinc was the principal cause of the phytotoxicity to the tree seedlings, although Mn and Cd may also have been phytotoxic in the most contaminated soil mixtures. Calcium deficiency seemed to play a role in the observed phytotoxicity. Exposed soybeans showed symptoms of Mn toxicity. A test of the effect of liming on remediation of the Zn and Mn phytotoxicity caused a striking decrease in Sr-nitrate extractable metals in soils and demonstrated that liming was critical to remediation and restoration.

  14. Zinc speciation in overbank sediments contaminated by mining and smelting activities.

    OpenAIRE

    Van Damme, An

    2010-01-01

    Toxische metalen kunnen onder verschillende chemische vormen, of species, voorkomen in het milieu. Kennis van de speciatie van metalen is essentieel voor een risicoanalyse van gecontamineerde bodems en sedimenten. De speciatie van metalen wordt beïnvloed door de bron en de geschiedenis van de contaminatie, evenals door de chemische condities. Het doel van deze studie is om de verweringsprocessen van metaalhoudende mineralen te reconstrueren in overstromingssedimenten stroomafwaarts van een vo...

  15. Changes in Mercury Deposition in a Mining and Smelting Region as Recorded in Tree Rings

    Czech Academy of Sciences Publication Activity Database

    Hojdová, Maria; Navrátil, Tomáš; Rohovec, Jan; Žák, Karel; Vaněk, A.; Chrastný, V.; Bače, R.; Svoboda, M.

    2011-01-01

    Roč. 216, 1/4 (2011), s. 73-82 ISSN 0049-6979 R&D Projects: GA ČR GP526/09/P404 Institutional research plan: CEZ:AV0Z30130516 Keywords : mercury * dendrochemistry * trees * geochemical archives Subject RIV: DD - Geochemistry Impact factor: 1.625, year: 2011

  16. [Leaching of nonferrous metals from copper-smelting slag with acidophilic microorganisms].

    Science.gov (United States)

    Murav'ev, M I; Fomchenko, N V

    2013-01-01

    The leaching process of copper and zinc from copper converter slag with sulphuric solutions of trivalent iron sulphate obtained using the association of acidophilic chemolithotrophic microorganisms was investigated. The best parameters of chemical leaching (temperature 70 degrees C, an initial concentration of trivalent iron in the leaching solution of 10.1 g/L, and a solid-phase content in the suspension of 10%) were selected. Carrying out the process under these parameters resulted in the recovery of 89.4% of copper and 39.3% of zinc in the solution. The possibility of the bioregeneration of trivalent iron in the solution obtained after the chemical leaching of slag by iron-oxidizingacidophilic chemolithotrophic microorganisms without inhibiting their activity was demonstrated.

  17. Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

    International Nuclear Information System (INIS)

    Peascoe, RA

    2001-01-01

    Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment of black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar

  18. 76 FR 29031 - National Emissions Standards for Hazardous Air Pollutants: Secondary Lead Smelting

    Science.gov (United States)

    2011-05-19

    ... Agency for Toxic Substances and Disease Registry BACT best available control technology BLDS bag leak... ODW Office of Drinking Water OECA Office of Enforcement and Compliance Assurance OHEA Office of Health... Affect Energy Supply, Distribution, or Use I. National Technology Transfer and Advancement Act J...

  19. Phytotoxicity of zinc and manganese to seedlings grown in soil contaminated by zinc smelting

    International Nuclear Information System (INIS)

    Beyer, W.N.; Green, C.E.; Beyer, M.; Chaney, R.L.

    2013-01-01

    Historic emissions from two zinc smelters have injured the forest on Blue Mountain near Palmerton, Pennsylvania, USA. Seedlings of soybeans and five tree species were grown in a greenhouse in a series of mixtures of smelter-contaminated and reference soils and then phytotoxic thresholds were calculated. As little as 10% Palmerton soil mixed with reference soil killed or greatly stunted seedlings of most species. Zinc was the principal cause of the phytotoxicity to the tree seedlings, although Mn and Cd may also have been phytotoxic in the most contaminated soil mixtures. Calcium deficiency seemed to play a role in the observed phytotoxicity. Exposed soybeans showed symptoms of Mn toxicity. A test of the effect of liming on remediation of the Zn and Mn phytotoxicity caused a striking decrease in Sr-nitrate extractable metals in soils and demonstrated that liming was critical to remediation and restoration. -- Highlights: •Zinc in smelter-contaminated acid soil was highly toxic to tree seedlings. •Phytotoxic thresholds (Zn in soil, leaves and roots) were estimated. •Liming greatly ameliorated the phytotoxicity. •Calcium deficiency played a role in the phytotoxicity. •Soybeans showed symptoms of Mn toxicity. -- This work estimates the phytotoxic thresholds of Zn to tree seedlings in smelter-contaminated soil and explains the interactions of Zn with Mn and Ca

  20. Oribatid mite communities in contaminated soils nearby a lead and zinc smelting plant in Zanjan, Iran

    NARCIS (Netherlands)

    Jamshidian, M.K.; Saboori, A.; Akrami, M.A.; van Straalen, N.M.

    2015-01-01

    Many studies have shown that the composition of invertebrate communities in soil changes under the influence of stressors in the soil ecosystem. Conversely, an observed altered community structure may be indicative of stress. In this study we aimed to investigate responses of oribatid mite

  1. Relating injury to the forest ecosystem near Palmerton, PA, to zinc contamination from smelting.

    Science.gov (United States)

    Beyer, W Nelson; Krafft, Cairn; Klassen, Stephen; Green, Carrie E; Chaney, Rufus L

    2011-10-01

    The forest on Blue Mountain, near Lehigh Gap, has been injured by emissions from two historical zinc (Zn) smelters in Palmerton, PA, located at the northern base of the mountain. The uppermost mineral soil and lower litter from sites along a transect, just south of the ridgetop, contained from 64 to 4400 mg/kg Zn. We measured forest metrics at 15 sampling sites to ascertain how forest structure, species composition and regeneration are related to soil concentrations of Zn, the probable principal cause of the injury. Understanding how ecotoxicological injury is related to soil Zn concentrations helps us quantify the extent of injury to the ecosystem on Blue Mountain as well as to generalize to other sites. The sum of canopy closure and shrub cover, suggested as a broadly inclusive measure of forest structure, was decreased to half at approximately 2060 mg/kg Zn (102 mg/kg Sr(N0(3))(2)-extractable Zn). Tree-seedling density was decreased by 80% (from 10.5/m(2) to 2.1/m(2)) at a much lower concentration: 1080 mg/kg Zn (59 mg/kg Sr(N0(3))(2)-extractable Zn). Changes in species composition and richness were not as useful for quantifying injury to the forest. Phytotoxicity, desiccation from exposure, and a gypsy moth infestation combined to form a barren area on the ridgetop. Liming the strongly acid Hazleton soils at the sites would partially ameliorate the observed phytotoxicity and should be considered in planning restoration. © Springer Science+Business Media, LLC (outside the USA) 2011

  2. Contamination of the O2 soil horizon by zinc smelting and its effect on woodlouse survival

    Science.gov (United States)

    Beyer, W.N.; Miller, G.W.; Cromartie, E.J.

    1984-01-01

    Samples of litter from the 02 horizon of Dekalb soil (loamyskeletal, mixed, mesic Typic Dystrochrept) were collected from 18 ridgetop sites on a transect that ran by two Zn smelters in Palmerton, Pa. Metal concentrations increased by regular gradations from a minimum at a site 105 km west of the smelters (67 mg/kg Zn, 0.85 mg/kg Cd, 150 mg/kg Pb, 11 mg/kg Cu) to a maximum 1.2 km east of the smelters (35,000 mg/kg Zn, 1300 mg/kg Cd, 3200 mg/kg Pb, 280 mg/kg Cu), and then decreased until they reached an eastern minimum at the easternmost site, 19 km from the smelters. An increase in the P concentrations near the smelters showed that the emissions were disrupting nutrient flow through the ecosystem. An increase in the pH near the smelters was attributed to the high concentrations of Zn. The log of the distance of the sites from the smelters was significantly correlated (r = - 0.80, p Zinc, cadmium, lead, copper, and sulfur were experimentally added, alone or in combination, to 02 litter collected far from any known source of metal emissions. The highest concentration of Zn added (20,000 mg/kg) was toxic enough to account for the mortality observed in the earlier test. A lower concentration of Zn (5000 mg/kg) as well as the concentration of Cd (500 mg/kg) tested also significantly (p < 0.05) increased the mortality of woodlice.

  3. Outdoor and indoor cadmium distributions near an abandoned smelting works and their relations to human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Spurgeon, David J., E-mail: dasp@ceh.ac.uk [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Lawlor, Alan [Centre for Ecology and Hydrology, Lancaster, Bailrigg, Lancaster LA1 4AP (United Kingdom); Hooper, Helen L. [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Wadsworth, Richard [Centre for Ecology and Hydrology, Lancaster, Bailrigg, Lancaster LA1 4AP (United Kingdom); Svendsen, Claus [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Thomas, Laura D.K. [MRC-HPA Centre for Environment and Health, Department of Epidemiology and Public health, Imperial College London (United Kingdom); Ellis, James K.; Bundy, Jacob G.; Keun, Hector C. [Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ (United Kingdom); Jarup, Lars [MRC-HPA Centre for Environment and Health, Department of Epidemiology and Public health, Imperial College London (United Kingdom)

    2011-12-15

    The relationship of measured or modelled Cd concentrations in soil, house dust and available to plants with human urinary Cd concentrations were assessed in a population living around a Cd/Pb/Zn smelter in the UK. Modelled air concentrations explained 35% of soil Cd variation indicating the smelter contributed to soil Cd loads. Multi-variate analysis confirmed a significant role of biological and life-style factors in determining urinary Cd levels. Significant correlations of urinary Cd with soil, house dust and modelled plant available Cd concentrations were not, however, found. Potential reasons for the absence of clear relationships include limited environmental contact in urban populations; the role of undefined factors in determining exposure; and the limited spatial scope of the survey which did not sample from the full pollution gradient. Further, the absence of any significant relationship indicates that environmental measures provide limited advantage over atmospheric model outputs for first stage human exposure assessment. - Highlights: > Environmental measurements indicate smelter pollution of a surrounding urban area. > Life-style and biology influenced U-Cd more than measured environmental levels. > Limited contact with outdoor environments may limit Cd uptake in urban populations. > Better life-style data could improve the attribution of human Cd exposure routes. > Measured Cd levels provide limited added exposure insight over dispersion models. - Measured and modelled environmental cadmium concentrations provide limited additional explanation of human urinary cadmium concentrations.

  4. Reduced expression of PARK2 in manganese-exposed smelting workers.

    Science.gov (United States)

    Fan, Ximin; Luo, Ying; Fan, Qiyuan; Zheng, Wei

    2017-09-01

    Manganese (Mn) is widely used in modern industries. Occupational exposure to Mn is known to cause clinical syndromes similar, but not identical to, Parkinson's disease. This human cohort study was designed to investigate if workers exposed to Mn altered the PARK2 gene expression, leading to Mn-induced neurotoxicity. Workers (n=26) occupationally exposed to Mn were recruited from a Mn-iron (Fe) alloy smelter, and control workers (n=20) without Mn-exposure were from an Fe smelter from Zunyi City in China. Subjects were matched with socioeconomic status and background for environmental factors. Metal concentrations were determined by atomic absorption spectrophotometry (AAS). Total RNA from the blood samples was isolated and analyzed by RT-PCR to quantify PARK2. The data showed that Mn concentrations in plasma, red blood cell (RBC) and saliva, and the cumulative Mn-exposure were about 2.2, 2.0, 1.7 and 3.0 fold higher, respectively, in Mn-exposed workers than those in control subjects (pworkers was significantly decreased by 42% as compared to controls (p<0.01). Linear regression analysis further established that the expression of PARK2 mRNA was inversely correlated with Mn levels in plasma, RBC and saliva, as well as the cumulative Mn exposure (p<0.01). Taken together, it seems likely that Mn exposure among smelters may lead to a reduced expression of PARK2, which may partly explain the Mn-induced Parkinsonian disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. 77 FR 555 - National Emissions Standards for Hazardous Air Pollutants From Secondary Lead Smelting

    Science.gov (United States)

    2012-01-05

    ... 331492 0205 \\a\\ North American Industry Classification System. \\b\\ Maximum Achievable Control Technology... protective. NRDC v. EPA, 529 F.3d 1077, 1083 (DC Cir. 2008). On May 19, 2011, the EPA published a proposed... dioxin formation. Finalizing work practice standards for mercury. Revising the requirements in the NESHAP...

  6. Mathematical model of silicon smelting process basing on pelletized charge from technogenic raw materials

    Science.gov (United States)

    Nemchinova, N. V.; Tyutrin, A. A.; Salov, V. M.

    2018-03-01

    The silicon production process in the electric arc reduction furnaces (EAF) is studied using pelletized charge as an additive to the standard on the basis of the generated mathematical model. The results obtained due to the model will contribute to the analysis of the charge components behavior during melting with the achievement of optimum final parameters of the silicon production process. The authors proposed using technogenic waste as a raw material for the silicon production in a pelletized form using liquid glass and aluminum production dust from the electrostatic precipitators as a binder. The method of mathematical modeling with the help of the ‘Selector’ software package was used as a basis for the theoretical study. A model was simulated with the imitation of four furnace temperature zones and a crystalline silicon phase (25 °C). The main advantage of the created model is the ability to analyze the behavior of all burden materials (including pelletized charge) in the carbothermic process. The behavior analysis is based on the thermodynamic probability data of the burden materials interactions in the carbothermic process. The model accounts for 17 elements entering the furnace with raw materials, electrodes and air. The silicon melt, obtained by the modeling, contained 91.73 % wt. of the target product. The simulation results showed that in the use of the proposed combined charge, the recovery of silicon reached 69.248 %, which is in good agreement with practical data. The results of the crystalline silicon chemical composition modeling are compared with the real silicon samples of chemical analysis data, which showed the results of convergence. The efficiency of the mathematical modeling methods in the studying of the carbothermal silicon obtaining process with complex interphase transformations and the formation of numerous intermediate compounds using a pelletized charge as an additive to the traditional one is shown.

  7. Damage to the forest ecosystem on Blue Mountain from zinc smelting

    Science.gov (United States)

    Beyer, W.N.

    1988-01-01

    Emissions from two zinc smelters in Palmerton, Pennsylvania, have caused widespread destruction of the forest on Blue Mountain. There have been striking changes in the species composition and structure of the community of vascular plants, as well as population reductions of lichens, mosses, arthropods inhabiting the letter, and amphibians. Reductions in the populations of decomposers of organic matter have led to an accumulation of litter on the forest floor. Zinc poisoning was diagnosed in a white-tailed deer, and lead poisoning was diagnosed in a shrew. White-tailed deer also contained high concentrations of cadmium.

  8. Development of Bubble Driven Flow CFD Model Applied for Aluminium Smelting Cells

    Directory of Open Access Journals (Sweden)

    Y.Q. Feng

    2010-09-01

    Full Text Available This paper presents the development of a computational fluid dynamics (CFD model for the study of bubble driven bath flow in aluminium reduction cells. For validation purposes, the model development was conducted using a full scale air -water model of part of an aluminium reduction cell as a test-bed. The bubble induced turbulence has been modelled by either modifying bubble induced turbulence viscosity directly or by modifying bubble induced turbulence kinetic energy in a standard k- ε turbulence model. The relative performance of the two modelling approaches has been examined through comparison with experimental data taken under similar conditions using Particle Image Velocimetry (PIV. Detailed comparison has been conducted by point-wise comparison of liquid velocities to quantify the level of agreement between CFD simulation and PIV measurement. Both models can capture the key flow patterns determined by PIV measurement, while the modified turbulence kinetic energy model gives better agreement with flow patterns in the gap between anode and cathode.

  9. Hot Corrosion of Inconel 625 Overlay Weld Cladding in Smelting Off-Gas Environment

    Science.gov (United States)

    Mohammadi Zahrani, E.; Alfantazi, A. M.

    2013-10-01

    Degradation mechanisms and hot corrosion behavior of weld overlay alloy 625 were studied. Phase structure, morphology, thermal behavior, and chemical composition of deposited salt mixture on the weld overlay were characterized utilizing XRD, SEM/EDX, DTA, and ICP/OES, respectively. Dilution level of Fe in the weldment, dendritic structure, and degradation mechanisms of the weld were investigated. A molten phase formed on the weld layer at the operating temperature range of the boiler, which led to the hot corrosion attack in the water wall and the ultimate failure. Open circuit potential and weight-loss measurements and potentiodynamic polarization were carried out to study the hot corrosion behavior of the weld in the simulated molten salt medium at 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). Internal oxidation and sulfidation plus pitting corrosion were identified as the main hot corrosion mechanisms in the weld and boiler tubes. The presence of a significant amount of Fe made the dendritic structure of the weld susceptible to preferential corrosion. Preferentially corroded (Mo, Nb)-depleted dendrite cores acted as potential sites for crack initiation from the surface layer. The penetration of the molten phase into the cracks accelerated the cracks' propagation mainly through the dendrite cores and further crack branching/widening.

  10. Vertically Integrated Structures: Essence and Specific Features of Functioning in the Mining and Smelting Complex of Ukraine Вертикально интегрированные структуры: сущность и особенности функционирования в горно-металлургическом комплексе Украины

    Directory of Open Access Journals (Sweden)

    Nusinov Volodymyr Ya.

    2013-10-01

    Full Text Available The goal of the article is identification of the essence of vertically integrated structures, consideration of problems and specific features of their functioning under conditions of development of the mining and smelting complex of Ukraine. Systemising and generalising scientific views, the authors form own vision of the essence of vertical integration, the result of which is creation of a vertically integrated structure. On the basis of the study of scientific approaches, the authors further develop identification of the essence of the vertically integrated structure, present characteristics of its properties and also identify advantages and shortcomings of its functioning. The article considers specific features of functioning of vertically integrated structures in the mining and smelting complex of Ukraine (on the example of activity of the Metinvest Group, which allowed detection of positive and negative issues of integration of mining and smelting enterprises into a single structure. It determines that the basis of the decision to unite (join enterprises is obtaining a positive synergetic effect. The prospect of further studies is the study of synergy during formation and functioning of vertically integrated structures in the mining and smelting complex of Ukraine.Целью статьи является определение сущности вертикально интегрированных структур, рассмотрение проблем и особенностей их функционирования в условиях развития горно-металлургического комплекса Украины. Систематизация и обобщение научных взглядов позволили сформировать собственное видение сущности вертикальной интеграции, результатом которой является создание ве

  11. Archaeological excavations on the iron-smelting site in Tõdva village / Mauri Kiudsoo, Jaak Mäll, Irita Kallis

    Index Scriptorium Estoniae

    Kiudsoo, Mauri, 1973-

    2009-01-01

    Tõdva rauasulatuskompleksi puhul on tegemist esimese uuritud viikingiaegse rauasulatusakohaga Eestis. Uudseks võib pidada šlakianalüüsidel baseeruvat avastust, et tõenäoliselt tunti peale soomaagi ka meretekkelisi raua-mangaanikonkretsioone

  12. Fe, Cr, Ni, Cu, Mg, Al, Ti, and S contents in plants and soil of heaps of nickel smelting works

    Energy Technology Data Exchange (ETDEWEB)

    Banasova, V; Hajduk, J

    1977-01-01

    The writers established the Fe, Ce, Cr, Ni, Ca, Mg, Al, Ti and S contents in the neopedon of heaps piling up from processing of nickel ore as well as in the plants: Cardaria draba, Salsola cali, Agropyrum repens, Bromus erectus, Calamagrostis epigeios, Cynodon dactylon and Matricaria inodora, growing on such heaps. Ca, Mg and S contents were found to be higher in dicotyledons and Fe, Al, Ti, Ni and Cr contents higher in monocotyledons. The analyzed dicotyledons appeared to be concentrators of Ca and S. Highest Fe, Al, Ti, Ni and Cr contents were found in individuals of the species Agropyrum repens. The neopedon as well as the plants had extraordinarily high Cr concentrations. The species Salsola cali has been found to possess an unusually higher affinity to the dump substrate after processing of nickel ore and to be a concentrator of Mg. 16 references, 1 table.

  13. Leaching of silicon from ferronickel (FeNi) smelting slag with sodium hydroxide solution at atmospheric pressure

    Science.gov (United States)

    Mufakhir, F. R.; Mubarok, M. Z.; Ichlas, Z. T.

    2018-01-01

    The present paper reports the leaching behavior of silicon from ferronickel slag under atmospheric pressure using sodium hydroxide solution. The effect of several experimental variables, namely concentration of leaching agent, operating temperature, stirring speed, and slurry density was investigated. The leaching kinetic was also investigated by using shrinking core model. It was determined that leaching of silicon from the slag was controlled by diffusion through product layer, although the activation energy was found to be 85.84 kJ/mol, which was unusually high for such a diffusion-controlled process.

  14. Improving the engineering-and-economical performance of ore-thermal electric furnaces in the smelting of silicomanganese

    Science.gov (United States)

    Kondrashov, V. P.; Pogrebisskiy, M. Ya; Lykov, A. G.; Rabinovich, V. L.; Bulgakov, A. S.

    2018-02-01

    Ways of increase of ore-heating electric furnaces, used for production of silicomanganese, engineering-and-economical performance are analyzed. Questions of data of the electric, thermal and technological modes of the furnace functioning collecting and processing for use in operation of an advanced control system of the furnace providing increase in technical and economic efficiency of technological process and an adaptability to quality of burden stock are considered.

  15. Misled about lead: an assessment of online public health education material from Australia's lead mining and smelting towns.

    Science.gov (United States)

    Sullivan, Marianne; Green, Donna

    2016-01-06

    This study assesses the accuracy and comprehensiveness of online public health education materials from the three Australian cities with active lead mines and or smelters: Broken Hill, Mount Isa and Port Pirie. Qualitative content analysis of online Australian material with comparison to international best practice where possible. All materials provided incomplete information about the health effects of lead and pathways of exposure compared to best practice materials. Inconsistent strategies to reduce exposure to lead were identified among the Australian cities, and some evidence-based best practices were not included. The materials normalised environmental lead and neglected to identify that there is no safe level of lead, or that primary prevention is the best strategy for protecting children's health. Health education materials need to clearly state health risks from lead across developmental stages and for sensitive populations, integrate a primary prevention perspective, and provide comprehensive evidence-based recommendations for reducing lead exposure in and around the home. Families who rely on information provided by these online public education materials are likely to be inadequately informed about the importance of protecting their children from exposure to lead and strategies for doing so.

  16. Injury to Akamatsu (Pinus densiflora Sieb. et Zucc. ) forest in the vicinity of the smelting works at Hitachi

    Energy Technology Data Exchange (ETDEWEB)

    Okanoue, M

    1958-03-01

    In the summer of 1965, smoke from a smelter at Hitachi caused injury to a national forest approximately one to three km distant. The smelter had been equipped with control devices and no previous injuries had been reported. An investigation of meteorological conditions at the time of the emission revealed the presence of a temperature inversion between Mt. Kamimine (594 m) and Sukegawa (52 m). However, these inversions are not uncommon in the area. Presumably, poisonous gas was emitted from the smelter chimney as a result of equipment malfunction just at the time of unfavorable meteorological conditions.

  17. Lead exposure of workers employed as tappers in a platinum smelting environment / Morné de Beer

    OpenAIRE

    De Beer, Morné

    2004-01-01

    The study was undertaken after initial surveys indicated that lead (Pb) was present at concentrations in excess of the occupational exposure limit (OEL) on the matte tapping floor (MTF). A follow up study was designed in accordance with the Occupational Exposure Sampling Strategy Manual (OESSM), to determine personal exposure levels of the tappers to Pb whom are employed on the MTF. Following the initial static samples taken during the identification phase, follow up static ...

  18. Investigation of Acidithiobacillus ferrooxidans in pure and mixed-species culture for bioleaching of Theisen sludge from former copper smelting.

    Science.gov (United States)

    Klink, C; Eisen, S; Daus, B; Heim, J; Schlömann, M; Schopf, S

    2016-06-01

    The aim of this study was to investigate the potential of bioleaching for the treatment of an environmentally hazardous waste, a blast-furnace flue dust designated Theisen sludge. Bioleaching of Theisen sludge was investigated at acidic conditions with Acidithiobacillus ferrooxidans in pure and mixed-species culture with Acidiphilium. In shaking-flask experiments, bioleaching parameters (pH, redox potential, zinc extraction from ZnS, ferrous- and ferric-iron concentration) were controlled regularly. The analysis of the dissolved metals showed that 70% zinc and 45% copper were extracted. Investigations regarding the arsenic and antimony species were performed. When iron ions were lacking, animonate (Sb(V)) and total arsenic concentration were highest in solution. The bioleaching approach was scaled up in stirred-tank bioreactors resulting in higher leaching efficiency of valuable trace elements. Concentrations of dissolved antimony were approx. 23 times, and of cobalt, germanium, and rhenium three times higher in comparison to shaking-flask experiments, when considering the difference in solid load of Theisen sludge. The extraction of base and trace metals from Theisen sludge, despite of its high content of heavy metals and organic compounds, was feasible with iron-oxidizing acidophilic bacteria. In stirred-tank bioreactors, the mixed-species culture performed better. To the best of our knowledge, this study is the first providing an appropriate biological technology for the treatment of Theisen sludge to win valuable elements. © 2016 The Society for Applied Microbiology.

  19. Analisis Hasil Investigasi Kecelakaan Kerja Pada Inalum Smelting Plant (ISP) PT Indonesia Asahan Aluminium Kuala Tanjung Tahun 2014

    OpenAIRE

    Ardila, Aprilia Rizki

    2016-01-01

    Occupational accident is work-related event that could cause injury or illness and even death.In the cycle of accident prevention, one of the important thing is how to conduct the accident investigation to find the factors that caused the accident. Accident investigation is essential to design prevention programs so the same accident will not happen again. Human Factors Analysis and Classification System (HFACS) is a method of occupational accidents analysis with a systematic a...

  20. The pH-dependent leaching behavior of slags from various stages of a copper smelting process: Environmental implications.

    Science.gov (United States)

    Jarošíková, Alice; Ettler, Vojtěch; Mihaljevič, Martin; Kříbek, Bohdan; Mapani, Ben

    2017-02-01

    The leaching behaviors of primary copper (Cu) slags originating from Ausmelt, reverbatory, and converter furnaces operating under a single technological process were compared to a residual slag tailing obtained by slag re-processing via flotation and metal recovery. The EN 12457-2 leaching test, used for assessment of the hazardous properties, was followed by the CEN/TS 14997 pH-static leaching test (pH range 3-12). Both leaching experiments were coupled with a mineralogical investigation of the primary and secondary phases as well as geochemical modeling. Metals (Cd, Cu, Pb, Zn) exhibit the highest leaching at low pH. Under acidic conditions (pH 3-6), Ausmelt slag and slag tailing exhibited higher metal leaching compared to other slag types. Very low leaching of metals (far below EU limits for non-hazardous waste) was observed at natural pH (7.9-9.0) for all the studied slag samples. In contrast, relatively high leaching of As was observed over the entire pH range, especially for Ausmelt slag (exceeding the EU limit for hazardous waste by 1.7×). However, geochemical modeling and scanning electron microscopy indicated that formation of stable Ca-Cu-Pb arsenates and the binding of As to newly formed Fe (oxyhydr)oxides play an important role in efficient As immobilization at the slag-water interface. In contrast, no controls were predicted for Sb, whose leaching was almost pH-independent. Nevertheless Sb leached concentrations at natural pH were below EU limit for hazardous waste. Re-processing of primary Cu slags for metal recovery, and subsequent co-disposal of the resulting slag tailing with dolomite-rich mine tailing and local laterite is suitable for stabilizing the remaining contaminants (except Sb) and limiting their leaching into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Long-term temporal and spatial changes in the richness and relative abundance of the inshore fish community of the British North Sea Coast

    Science.gov (United States)

    Henderson, Peter A.

    2017-09-01

    Changes in temporal and spatial composition of the British inshore North Sea fish community are reviewed. Sampling from the cooling water filter screens of power stations bordering the North Sea commenced in the early 1960s. To date, a total of 112 marine fish species have been recorded, a high proportion of the total inshore fish species complement of shallow North Sea British waters. The unrecorded top predators, such as large sharks, swordfish and tuna are not regularly observed in waters fish diversity and abundance in large industrialised estuaries such as the Thames and the Firth of Forth. Linked to spawning and nursery habitat gain, smelt, Osmerus eperlangus, and bass, Dicentrarchus labrax, have greatly increased in abundance. There is no evidence for a decline in species richness since the 1970s. However, elasmobranch species number has declined while two species Raja clavata and Scyliorhinus canicula have remained abundant and one, Mustelus asterias, has increased in abundance. It is argued that overexploitation and habitat destruction remain, as they have been for the last 300 years, the most serious threats to the health of North Sea inshore fish communities. There are no clear signs that climate change is causing species loss, although it may be influencing relative species abundance as species at the southern edge of their range such as the viviparous blenny, Zoarces viviparous, have declined in the southern British North Sea. Power station water temperature records do not show a warming trend, in some estuarine locations temperature has declined with reduced thermal pollution; the temperature record cannot explain the observed major changes in fish relative abundance observed since the 1970s.

  2. Long-term variation in a central California pelagic forage assemblage

    Science.gov (United States)

    Ralston, Stephen; Field, John C.; Sakuma, Keith M.

    2015-06-01

    A continuous 23 year midwater trawl survey (1990-2012) of the epipelagic forage assemblage off the coast of central California (lat. 36°30‧-38°20‧ N) is described and analyzed. Twenty taxa occurred in ≥ 10% of the 2037 trawls that were completed at 40 distinct station locations. The dominant taxa sampled by the 9.5 mm mesh net included a suite of young-of-the-year (YOY) groundfish, including rockfish (Sebastes spp.) and Pacific hake (Merluccius productus), two clupeoids (Engraulis mordax and Sardinops sagax), krill (Euphausiacea), cephalopods (Doryteuthis opalescens and Octopus sp.), and a variety of mesopelagic species, i.e., Diaphus theta, Tarltonbeania crenularis, "other" lanternfish (Myctophidae), deep-sea smelts (Bathylagidae), and sergestid shrimp. Annual abundance estimates of the 20 taxa were obtained from analysis of variance models, which included year and station as main effects. Principal components analysis of the abundance estimates revealed that 61% of assemblage variance was explained by the first three components. The first component revealed a strong contrast in the abundance of: (a) YOY groundfish, market squid (D. opalescens), and krill with (b) mesopelagics and clupeoids; the second component was associated with long-term trends in abundance. An evaluation of 10 different published oceanographic data sets and CTD data collected during the survey indicated that seawater properties encountered each year were significantly correlated with abundance patterns, as were annual sea-level anomalies obtained from an analysis of AVISO satellite information. A comparison of our findings with several other recent studies of biological communities occurring in the California Current revealed a consistent structuring of forage assemblages, which we conjecture is primarily attributable to large-scale advection patterns in the California Current ecosystem.

  3. Use of the Indicator of the Period of Outstanding Current Liabilities when Diagnosing Crisis at Mining and Smelting Enterprises Использование показателя периода непогашения текущих обязательств при диагностике кризиса на предприятиях горно-металлургического комплекса

    Directory of Open Access Journals (Sweden)

    Nusinova Yana V.

    2013-03-01

    Full Text Available The article substantiates methodical approaches to the use of the indicator of the period of outstanding current liabilities when diagnosing crisis at domestic mining and smelting enterprises. It reveals that these enterprises are the most vulnerable in the world financial and economic crisis, during the period of which production volumes dropped in physical terms, but increased together with sales in money terms, which was achieved by means of increase of prices and dollar rate. It states that one of the key tasks in solving the problems resulting from current company management is a necessity of permanent control over the level of current liabilities, the source of repayment of which, in majority of cases, is the proceeds from products sales. In this connection it offers to use, in addition to other indicators of diagnostics, the period of outstanding current liabilities, which is calculated using relation of current liabilities to the volume of sales of products in money terms, multiplied by 365 days. It offers to identify its lowest value, which would characterise the period during which an enterprise could suspend repayment of current liabilities without the risk of deteriorating the financial state down to the crisis level. It calculates and analyses factual values of the indicator at a number of mining and smelting enterprises of Ukraine for the period 2002 – 2011. It states that it is more expedient to use different values for different groups of enterprises as boundary values. It also offers to set the upper limit value of the period of outstanding current liabilities at the level of 1 year. It states that when this value is exceeded, the financial state of an enterprise is characterised as a critical situation.В статье обосновываются методические подходы к использованию показателя периода непогашения текущих обязательств при д

  4. High-resolution lake sediment reconstruction of industrial impact in a world-class mining and smelting center, Sudbury, Ontario, Canada

    International Nuclear Information System (INIS)

    Schindler, Michael; Kamber, Balz S.

    2013-01-01

    Highlights: • High-resolution sampling of a lake-sediment core. • Resolution of historical events in a smelter-impacted area. • Perturbation of Cu and Ni in a sediment core. • Fingerprinting sediments and pollutants using Pb isotopes and trace elements. - Abstract: A lake sediment core from Vermillion Lake, Sudbury, Ontario was tightly sampled and analyzed for a wide range of trace elements as well as for Pb isotopes. The data resolve multiple historical events in the 140-a history of logging and mining in the Sudbury area in unprecedented detail. Lead-210 data, 137 Cs activity and historical information on the start of anthropogenic activities in the Sudbury area were combined to derive an age model for the sedimentary column. Using the age information, it is possible to identify sediment sections enriched and depleted in trace metal(loid)s, particularly Ni and Cu, the two most relevant metals in the Sudbury area. Maxima and minima in the chronology of Ni and Cu coincide well with local production values for both elements until environmental regulations in the 1990s resulted in a decrease in their emission and drainage into Vermillion Lake. Differences in the deposition rates of Ni and Cu, trace-metal distribution patterns throughout the sedimentary column, Pb-isotope data, and comparison with data for local rocks and ores in the Sudbury area were used to identify the sources of pollutants in the early and late periods of mining activities. In addition, the environmental impact on the sediment itself was also studied via the variation of water content and organic matter. Finally, a surficial Fe–Mn-enriched layer with elevated concentrations of the oxy-anions (PO 4 ) 3− , (AsO 4 ) 4− , and (MoO 4 ) 2− was identified. This can be distinguished from accumulation of Zn and an increase in the Y / Ho ratio in the upper core sections, which likely imply increasing drainage of fertilizers into the Vermillion River watershed. The chemistry, mineralogy, and isotope composition of the Vermillion Lake sediment column thus contain a very detailed >140-a account of initial severe anthropogenic disturbance, the efforts of remediation and the effects of changing land use towards agricultural and recreational activities

  5. The Effect of Deposit Temperature on the Catalytic SO2-to-SO3 Conversion in a Copper Flash Smelting Heat Recovery Boiler

    Science.gov (United States)

    Lehmusto, Juho; Vainio, Emil; Laurén, Tor; Lindgren, Mari

    2018-02-01

    The aim of the work was to study the catalytic role of copper flash smelter deposit in the SO2-to-SO3 conversion. In addition, the effect of process gas temperature at 548 K to 1173 K (275 °C to 900 °C) on the amount of SO3 formed was addressed both in the absence and presence of genuine copper flash smelter deposit. The SO3 conversion rate changed as a function of process gas temperature, peaking at 1023 K (750 °C). A dramatic increase in the SO2-to-SO3 conversion was observed when process dust was present, clearly indicating that process dust catalyzes the SO2-to-SO3 conversion. Based on these results, the catalytic ability of the deposit may lead to sulfuric acid dew point corrosion.

  6. Sediment matrix characterization as a tool for evaluating the environmental impact of heavy metals in metal mining, smelting, and ore processing areas.

    Science.gov (United States)

    Ružičková, Silvia; Remeteiová, Dagmar; Mičková, Vladislava; Dirner, Vojtech

    2018-02-21

    In this work, the matrix characterization (mineralogy, total and local chemical composition, and total organic (TOC) and inorganic carbon (TIC) contents) of different types of sediments from mining- and metallurgy-influenced areas and the assessment of the impact of the matrix on the association of potentially hazardous metals with the mineral phases of these samples, which affect their mobility in the environment, are presented. For these purposes, sediment samples with different origins and from different locations in the environment were analyzed. Anthropogenic sediments from metal-rich post-flotation tailings (Lintich, Slovakia) represent waste from ore processing, natural river sediments from the Hornád River (Košice, Slovakia) represent areas influenced predominantly by the metallurgical industry, and lake sediments from a water reservoir Ružín (inflow from the Hornád and Hnilec Rivers, Slovakia) represent the impact of the metallurgical and/or mining industries. The total metal contents were determined by X-ray fluorescence (XRF) analysis, the local chemical and morphological microanalysis by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and the TOC and TIC contents by infrared (IR) spectrometry. The mobility/bioavailability of Cu, Pb, and Zn in/from sediments at the studied areas was assessed by ethylenediaminetetraacetic acid (EDTA) and acetic acid (AA) extraction and is discussed in the context of the matrix composition. The contents of selected potentially hazardous elements in the extracts were determined by the high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

  7. Impact of a lead mining-smelting complex on the forest-floor litter arthropod fauna in the new lead belt region of southeast Missouri

    Energy Technology Data Exchange (ETDEWEB)

    Watson, A.P.; Van Hook, R.I.; Jackson, D.R.; Reichle, D.E.

    1976-07-01

    Studies of biological activity within the litter horizons of a watershed contaminated by emissions from a lead-ore processing complex focused on the litter-arthropod food chain as a means of detecting perturbations in a heavy-metal contaminated ecosystem. Both point sources (smelter stack emissions) and fugitive sources (ore-handling processes, yard dusts, and exposed concentrate piles) contributed to the Pb, Zn, Cu, and Cd levels in the study area. Arthropod trophic level density, biomass, and heavy metal content were determined by analysis of specimens removed from litter by von Tullgren funnel extraction, taxonomically classified, and segregated into the trophic categories. Changes in litter decomposition were reflected in the dynamics of the litter arthropod community. Food-chain dilution of Pb, Zn, Cu, and Cd from litter to litter consumer was occurring, as indicated by the mean concentration factors. Accumulation of Pb by litter consumers was much less than that found for the other three heavy metals. In contrast, predatory arthropods on Crooked Creek Watershed either concentrated or equilibrated with respect to Pb, Zn, and Cd from their prey, as indicated by mean total predator concentration factors. A significant depression of the Ca, Mg, and K content litter occurred relative to the control within 0.8 km of the stack. Two mechanisms were postulated to explain this result: increased leaching of cations through the litter induced by a loss of cation exchange capacity, a decrease in pH, and a decrease in microbial immobilization of macronutrients; and a decreased uptake of macronutrients due to root damage produced by heavy-metal concentrations.

  8. Otolith shape analysis and mitochondrial DNA markers distinguish three sand smelt species in the Atherina boyeri species complex in western Mediterranean

    Science.gov (United States)

    Boudinar, A. S.; Chaoui, L.; Quignard, J. P.; Aurelle, D.; Kara, M. H.

    2016-12-01

    Atherina boyeri is a common euryhaline teleost fish in the Mediterranean and adjacent areas, which inhabits coastal and estuarine waters, including coastal lagoons and more rarely inland waters. Several recent studies have pointed the possible existence of three distinct groups or species, one lagoon/freshwater group and two 'punctuated and unpunctuated on the flanks' marine groups, within an A. boyeri species complex. This study is a combined approach using otolith shape and molecular markers to better define the structure of the species in the western Mediterranean. Genetic differentiation and species delimitation among nine Atherina boyeri populations from several marine and lagoon/brakish habitat sites in Algeria, Tunisia and France were investigated using three mitochondrial (control region, Cyt b and 16S) and one nuclear markers (2nd intron of S7). For further phylogenetic and phylogeographic study, we added sequences from Genbank covering more areas (Ionian Sea, Adriatic Sea, Tyrrhenian Sea, Black Sea, Atlantic). Five groups were found. Two of them perfectly corresponded to two species already recognized Atherina presbyter and Atherina hepsetus, both living in marine waters; and three additional, including Atherina boyeri (brackish and freshwater environments) and two independent groups of marine punctated and unpunctated individuals. Those findings are corroborated by the study of the otolith contour shape of 362 individuals of seven populations from different habitats using Fourier analysis. Individuals could be discriminated into five groups based on the first two functions (Wilk's lambda = 0.07, p < 0.001). Samples from Ziama inlet, marine punctuated individuals and unpunctuated marine specimens from Annaba's Gulf formed three well separated groups. Specimens from Mellah and Mauguio lagoons formed another group. The last one includes individuals from Bizerte and Thau lagoons. The divergences between them strongly support the potential species within the A. boyeri species complex.

  9. Spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a century-old nonferrous metal mining and smelting area in China.

    Science.gov (United States)

    Gong, Xing; Chen, Zhihua; Luo, Zhaohui

    2014-12-01

    This study first presents the spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a nonferrous metal mine area in China. Unconfined groundwater was polluted by Pb, Zn, As, and Cu, in order, while confined karst water in the mines showed pollution in the following sequence: Zn, Cd, Cu, Pb, and As. Pollution by Pb was widespread, while Zn, As, Cu, and Cd were found to be high in the north-central industrial region and to decrease gradually with distance from smelters and tailings. Vertically, more Pb, Zn, Cu, and Cd have accumulated in shallow Quaternary groundwater, while more As have migrated into the deeper fracture groundwater in the local discharge area. Zn, Cd, and Cu concentrations in groundwater along the riverside diminished owing to reduced wastewater drainage since 1977, while samples in the confluence area were found to have increasing contents of Pb, Zn, As, Cu, and Cd since industrialization began in the 1990s. Sources of heavy metals in groundwater were of anthropogenic origin except for Cr. Pb originated primarily from airborne volatile particulates, wastewater, and waste residues and deposited continuously, while Zn, Cd, and Cu were derived from the wastewater of smelters and leakage of tailings, which corresponded to the related soil and surface residue researches. Elevated As values around factories might be the result of chemical reactions. Flow patterns in different hydrogeological units and adsorption capability of from Quaternary sediments restricted their cross-border diffusion.

  10. AS SPECIATION AND EFFECTS OF PH AND PHOSPHATE ON THE MOBILIZATION OF AS IN SOILS FROM A LEAD SMELTING SITE. PUBLISHED IN ADVANCED PHOTON SOURCE ACTIVITY REPORT 2003.

    Science.gov (United States)

    Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and mineralogy were analyzed as a function of depth and surface distribution using bulk and microprobe XAS. These results were c...

  11. Smelting reduction rate of fine Wustite particles in a CO gas-conveyed bed; CO gas yuso sonai Wustite biryushi no yoyu kangen sokudo

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, S; Iguchi, Y [Nagoya Institute of Technology, Nagoya (Japan)

    1999-06-01

    Using a laboratory scale fine particles-gas conveyed bed, the reduction rates of liquid wustite with CO gas were measured. CO-CO{sub 2} mixtures having various flow rates and compositions were flowed downward through a cylindrical reactor maintained at a constant temperature of 1,723 to 1,823K. A batch of pure spherical wustite particles (mean dia.: 48.5 {mu}m) was concurrently fed into the reactor at a small constant rate and reduced in a hot zone. The reduction process was found to proceed in such a manner that metallic iron particles were enclosed inside a wustite droplet. Rate analysis was made of one dimensional mass balance equations for particles and gas in a steady moving bed under an isothermal condition using the reaction rate for a single particle taking the shrinkage into consideration. Under relatively small reducing potentials, it was concluded that the major fraction of overall reaction resistance is attributable to chemical reaction. However, under higher reducing potentials, the reduction process was estimated to include some mass transfer resistances within the liquid oxide phase. From the temperature dependence of forward chemical reaction rate constants, the activation energy was evaluated to be 90.6 kJ/mol. (author)

  12. Accumulation and environmental risk assessment of heavy metals in soil and plants of four different ecosystems in a former polymetallic ores mining and smelting area (Slovakia).

    Science.gov (United States)

    Demková, Lenka; Árvay, Július; Bobuľská, Lenka; Tomáš, Ján; Stanovič, Radovan; Lošák, Tomáš; Harangozo, Luboš; Vollmannová, Alena; Bystrická, Judita; Musilová, Janette; Jobbágy, Ján

    2017-04-16

    Heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in soils and plants of four different ecosystems (forest, grassland, agro and urban ecosystem) at different distances from the source of the pollution were analyzed in order to assess and compare soil contamination in the various ecosystems and determine the potential accumulation of plants depending on the place they inhabit. Correlation relationships among heavy metals in soils differ depending on the ecosystem, and between soil and plant, the heavy metals showed significant correlation for Cu, Mn, Ni, Pb and Zn. Contamination factor (C f ), degree of contamination (C d ) and pollution load index (PLI) were used in order to determine the level of environmental contamination of the study area. All studied ecosystems were rated as moderately contaminated (except agroecosystem, which was found as low contamination ecosystem) according to C d and extremely polluted according to PLI. The highest pollution in both cases was found in urban ecosystem, and Cd, Cu and Fe were determined as the biggest pollutants.

  13. Recycling of Zn-containing Fe-bearing steelmaking waste by the reducing smelting process in pig iron. I. Laboratory tests

    Directory of Open Access Journals (Sweden)

    Kendera Ján

    1997-09-01

    Full Text Available Results of the laboratory test treatment of the zinc containing steelwork dusts in a hot liquid pig iron are described. These results show that it is necessary to use an external reductant. The zinc content of the dust emission is ca. 20 %. The charge of the steel-works dusts diminished the Si and Mn content of pig iron.

  14. Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site

    Energy Technology Data Exchange (ETDEWEB)

    Impellitteri, Christopher A. [United States Environmental Protection Agency, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States)]. E-mail: Impellitteri.christopher@epa.gov

    2005-06-01

    Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were present also. The dominant geochemical phase was scorodite (FeAsO{sub 4}.2H{sub 2}O). The pH was controlled in the pH stat experiments by the addition of equinormal solutions of monoprotic (HNO{sub 3}), diprotic (H{sub 2}SO{sub 4}), or triprotic (H{sub 3}PO{sub 4}) acids. For many of the divalent metal cations, solution concentrations greatly decreased in the presence of phosphate. Solutions were also analyzed for anions. Evidence exists for sulfate release into solution. More As was released into solution at lower pH. A slight increase in solution arsenate occurs with the addition of phosphate, but the risk posed from the increased desorption/dissolution of As must be weighed against the decrease in solution concentrations of many metals especially Pb. If tailings from this site underwent acidification (e.g., acid mine drainage), in situ sequestration of metals by phosphate could be combined with placement of subsurface permeable reactive barriers for capture of As to reduce the risk associated with arsenic and trace metal mobilization. Results from this study could be used in risk management plans for sites similar to the Pb smelter site examined here.

  15. Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site

    International Nuclear Information System (INIS)

    Impellitteri, Christopher A.

    2005-01-01

    Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were present also. The dominant geochemical phase was scorodite (FeAsO 4 .2H 2 O). The pH was controlled in the pH stat experiments by the addition of equinormal solutions of monoprotic (HNO 3 ), diprotic (H 2 SO 4 ), or triprotic (H 3 PO 4 ) acids. For many of the divalent metal cations, solution concentrations greatly decreased in the presence of phosphate. Solutions were also analyzed for anions. Evidence exists for sulfate release into solution. More As was released into solution at lower pH. A slight increase in solution arsenate occurs with the addition of phosphate, but the risk posed from the increased desorption/dissolution of As must be weighed against the decrease in solution concentrations of many metals especially Pb. If tailings from this site underwent acidification (e.g., acid mine drainage), in situ sequestration of metals by phosphate could be combined with placement of subsurface permeable reactive barriers for capture of As to reduce the risk associated with arsenic and trace metal mobilization. Results from this study could be used in risk management plans for sites similar to the Pb smelter site examined here

  16. Multi-criteria ranking of copper concentrates according to their quality--an element of environmental management in the vicinity of copper--smelting complex in Bor, Serbia.

    Science.gov (United States)

    Nikolić, Djordje; Jovanović, Ivan; Mihajlović, Ivan; Zivković, Zivan

    2009-01-01

    The results of multi-criteria ranking of copper concentrates by their quality, according to their content of useful and harmful components, are presented in this paper. Cu, Ag and Au were taken as useful components, while Pb, Zn, As, Cd, Hg, Bi and Sb were considered as harmful with adequate weight parameters. Considering its specific role in copper metallurgy, sulfur in the concentrate was considered in two scenarios. In the first scenario S was considered as a useful and in the other one as a harmful component. The ranking is done by implementing the PROMETHEE/GAIA method with an additional implementation of the special PROMETHEE V method, using the standard limitations of the heavy metals content in the concentrate. In this way, it is possible to perform an optimization of the input charge for the copper extraction from two aspects. The first aspect covers benefits from the content of useful metals, while the second deals with the protection of the environment, considering the content of harmful components of the charge. Using multi-criteria decision making for the sake of ranking the quality of copper concentrates, as described in this paper, could be considered as a contribution to the methodology of forming the market price of this product.

  17. The effects of acid rainfall and heavy metal particulates on a boreal forest ecosystem near the Sudbury smelting region of Canada

    Science.gov (United States)

    T. C. Hutchinson

    1976-01-01

    Sulphur dioxide emissions have occurred on a gigantic scale at Sudbury from nickel-copper smelters. Soil erosion has followed the destruction of large areas of forest. Rainfall has been found highly acidic, frequently less than pH 3.0 in 1971. Metal accumulation in the soils (to distances of 50 km) have occurred for nickel and copper. The combination of heavy metal...

  18. Direct and indirect effects of metal contamination on soil biota in a Zn-Pb post-mining and smelting area (S Poland)

    International Nuclear Information System (INIS)

    Kapusta, Pawel; Szarek-Lukaszewska, Grazyna; Stefanowicz, Anna M.

    2011-01-01

    Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity. - Highlights: → Bioavailable zinc and cadmium reduce enchytraeid density. → Enchytraeids positively influence microbial respiration and biomass. → Total contents of heavy metals in soil are poor predictors of the distribution of plants and soil biota. - Elevated concentrations of exchangeable Zn and Cd reduce enchytraeid density and indirectly affect microbial activity adversely.

  19. Assessment of metal contamination in a small mining- and smelting-affected watershed: high resolution monitoring coupled with spatial analysis by GIS.

    Science.gov (United States)

    Coynel, Alexandra; Blanc, Gérard; Marache, Antoine; Schäfer, Jörg; Dabrin, Aymeric; Maneux, Eric; Bossy, Cécile; Masson, Matthieu; Lavaux, Gilbert

    2009-05-01

    The Riou Mort River watershed (SW France), representative of a heavily polluted, small, heterogeneous watershed, represents a major source for the polymetallic pollution of the Lot-Garonne-Gironde fluvial-estuarine system due to former mining and ore-treatment activities. In order to assess spatial distribution of the metal/metalloid contamination in the watershed, a high resolution hydrological and geochemical monitoring were performed during one year at four permanent observation stations. Additionally, thirty-five stream sediment samples were collected at representative key sites and analyzed for metal/metalloid (Cd, Zn, Cu, Pb, As, Sb, Mo, V, Cr, Co, Ni, Th, U and Hg) concentrations. The particulate concentrations in water and stream sediments show high spatial differences for most of the studied elements suggesting strong anthropogenic and/or lithogenic influences; for stream sediments, the sequence of the highest variability, ranging from 100% to 300%, is the following: Mo < Cu < Hg < As < Sb < Cd < Zn < Pb. Multidimensional statistical analyses combined with metal/metalloid maps generated by GIS tool were used to establish relationships between elements, to identify metal/metalloid sources and localize geochemical anomalies attributed to local geochemical background, urban and industrial activities. Finally, this study presents an approach to assess anthropogenic trace metal inputs within this watershed by combining lithology-dependent geochemical background values, metal/metalloid concentrations in stream sediments and mass balances of element fluxes at four key sites. The strongest anthropogenic contributions to particulate element fluxes are 90-95% for Cd, Zn and Hg in downstream sub-catchments. The localisation of anthropogenic metal/metalloid sources in restricted areas offers a great opportunity to further significantly reduce metal emissions and restore the Lot-Garonne-Gironde fluvial-estuarine ecosystem.

  20. Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the copper mining and smelting complex Bor (Serbia).

    Science.gov (United States)

    Antonijević, M M; Dimitrijević, M D; Milić, S M; Nujkić, M M

    2012-03-01

    In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As. This journal is © The Royal Society of Chemistry 2012

  1. Direct and indirect effects of metal contamination on soil biota in a Zn-Pb post-mining and smelting area (S Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Kapusta, Pawel, E-mail: p.kapusta@botany.pl [Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow (Poland); Szarek-Lukaszewska, Grazyna; Stefanowicz, Anna M. [Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow (Poland)

    2011-06-15

    Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity. - Highlights: > Bioavailable zinc and cadmium reduce enchytraeid density. > Enchytraeids positively influence microbial respiration and biomass. > Total contents of heavy metals in soil are poor predictors of the distribution of plants and soil biota. - Elevated concentrations of exchangeable Zn and Cd reduce enchytraeid density and indirectly affect microbial activity adversely.

  2. [Concentrations and Component Profiles PAHs in Surface Soils and Wheat Grains from the Cornfields Close to the Steel Smelting Industry in Handan, Hebei Province].

    Science.gov (United States)

    Wu, Di; Wang, Yi-long; Liu, Wei-jian; Chen, Yuan-chen; Fu, Xiao-fang; Tao, Shu; Liu, Wen-xin

    2016-02-15

    In this study, paired surface soil and mature wheat grain samples were collected in the cornfields near the large Handan Steel Manufacturer; and the total concentrations and compositional profiles of the parent PAHs were measured, then the spatial distribution characteristics and correlation with total organic carbon fractions in soil were determined. Accordingly, a preliminary source identification was performed, and the association between PAHs in surface soil and wheat grain was briefly discussed. The median concentration of total PAHs in surface soils from the cornfields of Handan was 398.9 ng x g(-1) (ranged from 123.4 ng x g(-1) to 1626.4 ng x g(-1), where around 18% and 10% of all the studied soil samples were over the corresponding quality criteria for total PAHs and B [a] P in soils, respectively. The MMW and HMW species were the main components in the compositional profiles of surface soils. Based on the specific isomeric ratios of PAHs species, coal/biomass combustion and transportation fuel (tail gas) were the dominant mixed sources for the local PAHs emission. The fractions of surface soil TOC had significant positive correlations with the total PAHs and also with the individual components with different rings. In addition, the median concentration of total PAHs in wheat grains collected in the cornfields near the Handan Steel Manufacture was 27.0 ng x g(-1) (ranged from 19.0-34.0 ng x g(-1)). The levels in wheat grains were not high, and lower than the related hygienic standards of food proposed by EU and China. The LMW and MMW PAHs with 2 to 4 rings occupied a larger proportion, more than 84% of the total PAHs, which was largely different from the component profiles in surface soils. This situation suggested that the local sources of PAHs in wheat grains may originate not only from surface soil via root absorption and internal transportation, but also from ambient air through dry and wet deposition on the leaf surface (stoma).

  3. A low-energy set-up for gamma-ray spectrometry of NORM tailored to the needs of a secondary smelting facility

    OpenAIRE

    Lutter, Guilome; Vandael Schreurs, Indy; Croymans, Tom; Schroeyers, Wouter; Schreurs, Sonja; Hult, Mikael; Marissens, Gert; Stroh, Heiko; Tzikaa, Faidra

    2017-01-01

    A measurement station dedicated for quantitative radiological characterisation of naturally occurring radio-nuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplificati...

  4. A low-energy set-up for gamma-ray spectrometry of NORM tailored to the needs of a secondary smelting facility.

    Science.gov (United States)

    Lutter, G; Schreurs, I Vandael; Croymans, T; Schroeyers, W; Schreurs, S; Hult, M; Marissens, G; Stroh, H; Tzika, F

    2017-08-01

    A measurement station dedicated for quantitative radiological characterisation of naturally occurring radionuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplification (for gamma-ray energies below 250keV) and low amplification. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Fluktuationen der Fischfauna im Elbe-Ästuar als Indikator für ein gestörtes Ökosystem

    Science.gov (United States)

    Köhler, Angela

    1981-09-01

    During 1978, 22 fish species (in particular Anguilla anguilla L., Platichthys flesus L., Osmerus eperlanus L., Gasterosteus aculeatus L., Lampetra fluviatilis L., Alosa fallax [Lacepede], Gymnocephalus cernua L., Clupea harengus L. and Sprattus sprattus L.), sampled at the intake of the cooling system in the nuclear power plant at Brunsbüttel (Elbe estuary), were analyzed for quantities and size distribution. The data obtained were correlated to abiotic factors, such as water temperature, water outflow from the upper Elbe river, salinity and oxygen content. Spawning times and seasonal migrations of the fish species investigated corresponded to appropriate temperatures of the Elbe water. The diversity of fish species from the cooling water proved to be representative for the ichthyo-fauna of this particular estuarine area. At least 190 tons of fish per year were estimated to be annihilated by the suction of cooling water into the nuclear power plant. In spite of the progressive development of regional industries and the increasing discharges of cooling water, temperature in the estuary has remained largely unaffected up till now. The oxygen content of the heavily polluted lower Elbe river, however, has become mainly dependent on the amount of fresh water flowing from the upper Elbe river. Up to 1978, oxygen levels of 80 90 % were recorded only in the mouth of the Elbe, thus meeting the requirements for the continuous occurrence of fish species typical for this estuarine area. Varying oxygen concentrations downstream of Hamburg and at Brunsbüttel are considered to be responsible for migrations of certain fish species (mainly flounder and smelt) between the Brunsbüttel region and their habitats further upstream which were occupied before the process of industrialisation initiated. This was reflected by the size of the samples taken from various fishes. During an eventual hazard of the industrial filter plants at Brunsbüttel in May 1978 an extreme oxygen depletion

  6. Survival of radio-tagged Atlantic salmon ( Salmo salar L.) and trout ( Salmo trutta L.) smolts passing a reservoir during seaward migration

    DEFF Research Database (Denmark)

    Jepsen, Niels; Aarestrup, Kim; Økland, F.

    1998-01-01

    tagged with internal miniature radio-transmitters, and released in the river just upstream the reservoir on May 1, 1996. The salmon smelts were hatchery-reared, while the trout smelts were wild fish, caught in a smelt trap. The tagged smelts were tracked daily for 3 weeks, and when possible the cause...

  7. Search Results | Page 835 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-01-01

    ferrous smelting pollution in three US communities, investigating how the smelting industry successfully delayed pollution control measures for nearly a century. Published date. January 1, 2015. Journal articles. REPRODUCTIVE HEALTH ...

  8. Experimental Study of the Melting and Reduction Behaviour of Ore Used in the HIsarna Process

    NARCIS (Netherlands)

    Qu, Y.

    2013-01-01

    The HIsarna is a coal-based smelting reduction process for ironmaking to drastically reduce CO2 emission and is one of the most promising alternative ironmaking processes under development in the world. The furnace consists of two inter-connected reactors: i) a smelting cyclone, ii) a smelting

  9. The Effect of CaO on Gas/Slag/Matte/Tridymite Equilibria in Fayalite-Based Copper Smelting Slags at 1473 K (1200 °C) and P(SO2) = 0.25 Atm

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2018-04-01

    Fundamental experimental studies have been undertaken to determine the effect of CaO on the equilibria between the gas phase (CO/CO2/SO2/Ar) and slag/matte/tridymite phases in the Cu-Fe-O-S-Si-Ca system at 1473 K (1200 °C) and P(SO2) = 0.25 atm. The experimental methodology developed in the Pyrometallurgy Innovation Centre was used. New experimental data have been obtained for the four-phase equilibria system for fixed concentrations of CaO (up to 4 wt pct) in the slag phase as a function of copper concentration in matte, including the concentrations of dissolved sulfur and copper in slag, and Fe/SiO2 ratios in slag at tridymite saturation. The new data provided in the present study are of direct relevance to the pyrometallurgical processing of copper and will be used as an input to optimize the thermodynamic database for the copper-containing multi-component multi-phase system.

  10. Determination of fecundity in cephalopods can be particularly ...

    African Journals Online (AJOL)

    spamer

    Atl. Fish. 14: 67–72. HOAR, W. S. 1969 — Reproduction. In Fish Physiology 3. Hoar,. W. S. and D. J. Randall (Eds). New York; Academic Press: 1–72. HUNTER, J. R. and B. J. MACEWICZ 1985 — Rates of atresia in the ovary of captive and wild northern anchovy, Engraulis mordax. Fishery Bull., Wash. 83(2): 119–136.

  11. Vrcholně středověká hornická sídliště se zvláštním zřetelem k lokalitě Kremsiger (k.ú. Přísečnice).

    OpenAIRE

    Derner, Kryštof

    2017-01-01

    (in English): The issue is focused on the survey and dig on the mining settlement Kremsiger in Ore Mountain. We discovered well planed and perhaps measured urbanism of the site. Our excavation took luckily place on the house with traces of ore assaing activity. In the issue we discuss the possibility of ore smelting directly on the mining settlements. We found out, that this activity is not exceptional, although there is no evident reason for avoiding the smelting in central smelting places. ...

  12. Two new species of nematodes (Nematoda) from highly mineralized rivers of Lake El'ton basin, Russia.

    Science.gov (United States)

    Gusakov, Vladimir A; Gagarin, Vladimir G

    2016-09-05

    Two new nematode species, Mesodorylaimus rivalis sp. n. and Allodiplogaster media sp. n., from the highly mineralized rivers of the El'ton Lake basin (Russia) are described and illustrated from numerous mature females and males. Mesodorylaimus rivalis sp. n. is similar to M. vulvapapillatus Bagaturia & Eliava, 1966, but differs from it in the longer body, shorter spicules and longer female prerectum. Allodiplogaster media sp. n. resembles A. lupata (Shoshin, 1989) Kanzaki, Ragsdale & Giblin-Davis, 2014 and A. mordax (Shoshin, 1989) Kanzaki, Ragsdale & Giblin-Davis, 2014, but differs from the first species in having a shorter pharynx, shorter outer labial setae, longer spicules and different ratio between anterior and posterior pharynx sections, and from A. mordax in the thinner body, shorter pharynx and longer spicules.

  13. Summary of a Situation from Laboratory Investigation of Yugoslav Nickel Bearing Ores by Segregation-Flotation-Magnetic Separation

    OpenAIRE

    Krstev, Boris; Ilic, Ilija

    1988-01-01

    A huge list of current laterite operations or laterites processing is following: Fe - ni smelting, Matte smelting, Reduction roasting-ammonia leaching and HPA leaching. Apart from the above mentioned process routes, there have been many attempts to develop processes know as alternative processes, which have included: Sulphuric, Nitric acid leaching, Chlorine leaching, Acid pugging and sulphating roast, especially Segregation Process etc.

  14. 75 FR 8807 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2010-02-26

    ... Perchloroethylene Dry X X X X Cleaning. N Hard and Decorative X X X X Chromium Electroplating and Chromium Anodizing... Furniture X X X X Manufacturing Operations. KK Printing and Publishing X X X X Industry. LL Primary Aluminum... Primary Copper Smelting X X X RRR Secondary Aluminum X X X Production. TTT Primary Lead Smelting.. X X X...

  15. Assessment of heavy metal pollution in drinking water due to mining ...

    African Journals Online (AJOL)

    Mining and smelting activities are the main causes for the increasing pollution of heavy metals from water sources. The toxicity of these heavy metals from the mining, milling and smelting companies can cause harmful and even lethal effects on the human health. The objective of this study was to investigate the level of As, ...

  16. Chemical characterization and local dispersion of slag generated by ...

    African Journals Online (AJOL)

    SAM

    2014-05-07

    May 7, 2014 ... Pb from acid batteries includes their rupture, draining of the acid, separation of the components containing Pb and its recovery by smelting (Faé et al., 2011). During the smelting process, a solid material called "slag" is generated. It contains a high concentration of Pb, among other toxic elements (Coya et al.

  17. A new species of Lonchophylla Thomas (Chiroptera: Phyllostomidae) from Ecuador

    Science.gov (United States)

    Albuja V., Luis; Gardner, Alfred L.

    2005-01-01

    We describe Lonchophylla orcesi, sp. nov., from the Choco, a region of high biotic diversity, endemism, and rainfall along the western Andean slopes and Pacific lowlands of Colombia and Ecuador. One of the largest known Lonchophylla, it occurs sympatrically with at least two other species of Lonchophylla including the similar, but somewhat smaller L. robusta. We also recognize L. concava as a Middle American Province species distinct from L. mordax of Brazil and Bolivia on the basis of cranial and dental features.

  18. Identification of contamination in a lake sediment core using Hg and Pb isotopic compositions, Lake Ballinger, Washington, USA

    International Nuclear Information System (INIS)

    Gray, John E.; Pribil, Michael J.; Van Metre, Peter C.; Borrok, David M.; Thapalia, Anita

    2013-01-01

    Highlights: ► Hg and Pb concentration and isotopic compositions traced anthropogenic sources. ► Concentrations and metal loadings of Hg and Pb increased during the smelting period. ► Hg isotopic compositions changed during smelting compared to the pre-smelting period. ► Data indicate mass independent fractionation of Hg isotopes. - Abstract: Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected from Lake Ballinger, near Seattle, Washington, USA. Lake Ballinger has been affected by input of metal contaminants emitted from the Tacoma smelter, which operated from 1887 to 1986 and was located about 53 km south of the lake. Concentrations and loadings of Hg and Pb in Lake Ballinger increased by as much as three orders of magnitude during the period of smelting as compared to the pre-smelting period. Concentrations and loadings of Hg and Pb then decreased by about 55% and 75%, respectively, after smelting ended. Isotopic compositions of Hg changed considerably during the period of smelting (δ 202 Hg = −2.29‰ to −0.38‰, mean −1.23‰, n = 9) compared to the pre-smelting period (δ 202 Hg = −2.91‰ to −2.50‰, mean −2.75‰, n = 4). Variations were also observed in 206 Pb/ 207 Pb and 208 Pb/ 207 Pb isotopic compositions during these periods. Data for Δ 199 Hg and Δ 201 Hg indicate mass independent fractionation (MIF) of Hg isotopes in Lake Ballinger sediment during the smelting and post-smelting period and suggest MIF in the ore smelted, during the smelting process, or chemical modification at some point in the past. Negative values for Δ 199 Hg and Δ 201 Hg for the pre-smelting period are similar to those previously reported for soil, peat, and lichen, likely suggesting some component of atmospheric Hg. Variations in the concentrations and isotopic compositions of Hg and Pb were useful in tracing contaminant sources and the understanding of the depositional history of sedimentation in Lake Ballinger

  19. Dust from Zambian smelters: mineralogy and contaminant bioaccessibility

    Czech Academy of Sciences Publication Activity Database

    Ettler, V.; Vítková, M.; Mihaljevič, M.; Šebek, O.; Klementová, Mariana; Veselovský, F.; Vybíral, P.; Kříbek, B.

    2014-01-01

    Roč. 36, č. 5 (2014), s. 919-933 ISSN 0269-4042 Institutional support: RVO:61388980 Keywords : Dust * Metal smelting * Copper * Cobalt * Solid speciation Subject RIV: CA - Inorganic Chemistry Impact factor: 2.566, year: 2014

  20. Arsenic Methyltransferase

    Science.gov (United States)

    The metalloid arsenic enters the environment by natural processes (volcanic activity, weathering of rocks) and by human activity (mining, smelting, herbicides and pesticides). Although arsenic has been exploited for homicidal and suicidal purposes since antiquity, its significan...

  1. HIGHLY REFRACTORY CRUCIBLES OF STABILIZED ZIRCONIA FOR INDUCTION MELTING OF THE PLATINUM GROUP METALS, FABRICATED BY VIBROCASTING

    Directory of Open Access Journals (Sweden)

    V. V. Primachenko

    2012-01-01

    Full Text Available As the result of the studies at PJSC « UKRNIIO them. A.S.Berezhnogo» the technology and commercial production of crucibles from stabilized zirconia for the smelting of platinum group metals are develop

  2. HIGHLY REFRACTORY CRUCIBLES OF STABILIZED ZIRCONIA FOR INDUCTION MELTING OF THE PLATINUM GROUP METALS, FABRICATED BY VIBROCASTING

    OpenAIRE

    V. V. Primachenko; V. V. Martynenko; I. G. Szulik; I. A. Kushchenko

    2012-01-01

    As the result of the studies at PJSC « UKRNIIO them. A.S.Berezhnogo» the technology and commercial production of crucibles from stabilized zirconia for the smelting of platinum group metals are develop

  3. Ezeh et al (17).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Source apportionment results by PCA resolved five sources (Soil dust, 31 %; Sea ... Non-ferrous smelting, 12 %; Heavy oil combustion, 10 %; Biomass burning, 9 %; Sea spray, 6 % ) for PM ..... classified as a non-toxic metal; however exposure.

  4. Headaches among residents within the Selebi Phikwe Nickel ...

    African Journals Online (AJOL)

    copper (Ni-Cu) mining and smelting environment in Botswana are investigated using questionnaires and statistical package for social sciences (SPSS). Interpreted results from respondents indicated that all of the health service providers, 80% of ...

  5. PROSPECTS FOR COKE BREEZE RECOVERY

    Directory of Open Access Journals (Sweden)

    D. N. Mihnovets

    2012-01-01

    Full Text Available Researches give grounds to believe in the possibility of receiving briquettes from coke waste mixed with peat dry coal and their use for smelting iron in the cupola or as a household fuel.

  6. Ferronickel Preparation from Nickeliferous Laterite by Rotary Kiln-Electric Furnace Process

    Science.gov (United States)

    Li, Guanghui; Jia, Hao; Luo, Jun; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    Nickel is an important strategic metal, which is mainly used for stainless steel production. In the recent years, ferronickel has been used as a substitute for electrolytic nickel for alleviating the cost of stainless steel production. Rotary kiln-electric furnace (RKEF) smelting is currently the world-wide mainstreaming process for ferronickel production from nickeliferous laterite ore, in spite of the high power consumption. In this study, aiming to provide some meaningful guidance for ferronickel production of RKEF smelting, reductive roasting followed by smelting process was carried out. The conditions including reducing parameters (roasting temperature and time) and smelting parameters (coke dosage, CaO dosage, melting temperature and time) were ascertained. The metal recovery ratios, as well as Ni, Fe, S and P content of ferronickel were considered. The results showed that a ferronickel containing 10. 32 wt. % Ni was obtained from a laterite with 1. 85 wt. % Ni, the nickel recovery ratio was about 99%.

  7. Processing of low- grade nickel bearing laterites

    OpenAIRE

    Krstev, Boris; Ilic, Ilija

    1999-01-01

    A combination of current trends and developments may undermine the sulphides supremacy and might tip the balance in favour of laterites for new investigations or projects. A list of current laterite operations or laterites processing today is following: Ferronickel smelting, Matte smelting, Reduction roasting-ammonia leaching and High pressure sulphuric acid leaching.Apart from the above mentioned process routes, there have been many attempts to develop processes know as alternative processes...

  8. Fish larvae from the Gulf of California

    Directory of Open Access Journals (Sweden)

    Gerardo Aceves-Medina

    2003-03-01

    Full Text Available Taxonomic composition of fish larvae was analysed from 464 plankton samples obtained during 10 oceanographic surveys in the Gulf of California between 1984 and 1988. We identified 283 taxa: 173 species, 57 genera, and 53 families. Tropical and subtropical species predominated except during the winter, when temperate-subarctic species were dominant. The most abundant species were the mesopelagic Benthosema panamense, Triphoturus mexicanus and Vinciguerria lucetia, but the coastal pelagic species Engraulis mordax, Opisthonema spp., Sardinops caeruleus and Scomber japonicus were also prominent. The taxonomic composition of the ichthyoplankton shows the seasonality of the Gulf as well as environmental changes that occurred between the 1984-1987 warm period and the 1956-1957 cool period previously reported. The presence of E. mordax larvae as one of the most abundant species in the Gulf provides evidence of the reproduction of this species two years before the development of the northern anchovy fishery and the decline of the sardine fishery in the Gulf of California.

  9. Non-polluting metal production network

    Energy Technology Data Exchange (ETDEWEB)

    Kojo, I.V.; Hanniala, P. [Outokumpu Engineering Conctractors OY, Espoo (Finland)

    2001-07-01

    The Flash Smelting process of copper is described. The process is characterised by low external energy utilization, therefore low greenhouse gas emissions. In addition to energy efficiency the sealed process gives an economic incentive to eliminate the emissions from the smelting process by capturing the dust in a gas cleaning system and in the sulfuric acid plant, following the gas cleaning. Besides the energy efficiency and environmental advantages the Flash Smelting Technology also boast high flexibility and high specific capacity, due to the better understanding of the combustion phenomena taking place in the oxidation of copper-iron-sulfur concentrates, which is most effective in an even suspension. This process has been intensively developed and as a result has been widely utilized for production of copper and nickel matte, elemental sulfur, and blister from both concentrates and matte or from mixture of matte and concentrate. The paper illustrates some options by describing examples of how Direct-to-Blister Flash Smelting or matte production in any smelting process combined with Flash Converting could be adapted to some existing smelters, and how these combinations would benefit smelters by not only lowering greenhouse gas emissions, but also increasing production and decreasing operating cost with a relatively small investment of capital. 5 refs., 2 tabs., 3 figs.

  10. Primary Copper Smelter and Refinery as a Recycling Plant—A System Integrated Approach to Estimate Secondary Raw Material Tolerance

    Directory of Open Access Journals (Sweden)

    Olof Forsén

    2017-10-01

    Full Text Available The primary production of sulfide concentrates includes smelting to copper matte or blister copper, conversion of matte to blister copper, and refining to copper. Smelting, converting, and fire-refining can use a limited amount of secondary materials. Molten copper can effectively dissolve many metals, from valuable noble metals to harmful impurities such as bismuth. However, some of the impurity metals in copper are valuable in other applications. In this paper, we outline the main material flows in copper smelting and electrorefining and describe how minor metals can be recovered from secondary raw materials using copper as a carrier material. We will use a system integrated approach to define the factors that affect the recovery of different metals and copper quality. Metals typical in copper production are used as examples, like noble metals, As, Bi, Se, and Te, including metals in the EU critical raw materials list like PGM and Sb.

  11. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Quentin C. Berg; Stephen P. Carpenter; Dady Dadyburjor; Jason C. Hissam; Manoj Katakdaunde; Liviu Magean; Abha Saddawi; Alfred H. Stiller; John W. Zondlo

    2006-03-07

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of carbon electrodes for Direct Carbon Fuel Cells (DCFC), and on carbon foam composites used in ballistic armor, as well as the hydrotreatment of solvents used in the basic solvent extraction process. A major goal is the production of 1500 pounds of binder pitch, corresponding to about 3000 pounds of hydrotreated solvent.

  12. Living on the edge: making and moving iron from the ‘outside’ in Anglo-Saxon England

    DEFF Research Database (Denmark)

    Birch, Thomas

    2011-01-01

    The production of iron in Anglo-Saxon England is little understood due to the lack of evidence. There are less than a dozen iron smelting sites known. This is a distinct contrast to the wealth of evidence of iron smelting during the Roman period. Should we believe that the Anglo-Saxon world......-west Europe emphasises how marginal they were in society, along with their goods. The value of items coming from the ‘outside’ was heightened as they came from the distant unknown, the unfamiliar. In order to understand the dynamic role of iron in Anglo Saxon society, we must review the negative evidence...... of iron smelting, and the evidence for smithing. This should be considered with reference to the literary evidence available to us in the context of the Migration period in northwest Europe. Iron production in early Anglo-Saxon England should also be sought after using archaeological prospection...

  13. Carbothermic Reduction of Nickeliferous Laterite Ores for Nickel Pig Iron Production in China: A Review

    Science.gov (United States)

    Rao, Mingjun; Li, Guanghui; Jiang, Tao; Luo, Jun; Zhang, Yuanbo; Fan, Xiaohui

    2013-11-01

    Both the consumption and production of crude stainless steel in China rank first in the world. In 2011, the nickel production in China amounted to 446 kilotons, with the proportion of electrolytic nickel and nickel pig iron (NPI) registering 41.5% and 56.5%, respectively. NPI is a low-cost feedstock for stainless steel production when used as a substitute for electrolytic nickel. The existing commercial NPI production processes such as blast furnace smelting, rotary kiln-electric furnace smelting, and Krupp-Renn (Nipon Yakin Oheyama) processes are discussed. As low-temperature (below 1300°C) reduction of nickeliferous laterite ores followed by magnetic separation could provide an alternative avenue without smelting at high temperature (~1500°C) for producing ferronickel with low cost, the fundamentals and recent developments of the low-temperature reduction of nickeliferous laterite ores are reviewed.

  14. Residual salts separation from metal reduced electrolytically in a LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Hur, Jin Mok; Oh, Seung Chul; Hong, Sun Seok; Seo, Chung Seok; Park, Seong Won

    2005-01-01

    The PWR spent oxide fuel can be reduced electrolytically in a hot molten salt for the conditioning and the preparation of a metallic fuel. Then the metal product is smelted into an ingot to be treated in the post process. Incidentally, the residual salt which originated from the molten salt and spent fuel elements should be separated from the metal product during the smelting. In this work, we constructed a surrogate material system to simulate the salt separation from the reduced spent fuel and studied the vaporization behaviors of the salts

  15. Strength of briquettes made of Cu concentrate and carbon-bearing materials

    Directory of Open Access Journals (Sweden)

    B. Oleksiak

    2015-01-01

    Full Text Available In the present paper, results of the research on application of residual fine-grained, carbon-bearing materials as coke substitutes in the shaft process of copper matter smelting are discussed. The addition was introduced into the charge as a component of concentrate-made briquettes, then, its effects on properties of the obtained briquettes were analysed for their compressive and drop strengths. The results of investigations confirmed the potential use of proposed alternative fuels (as briquette components in the process of copper matte smelting.

  16. Process and device for continuous measurement of the level of a radioactive glass melt

    International Nuclear Information System (INIS)

    Ritter, H.

    1987-01-01

    The glass melt runs into a high quality steel mould in the form of a jet at the bottom exit of the smelting furnace or reservoir. The smelting furnace or reservoir and the high quality steel mould can be made part of an electrical circuit by suitable insulation measures relative to one another and relative to the earth potential. The glass melt jet is used as a variable resistance in this circuit, as its resistance will decrease with its decreasing length due to the increasing level in the mould. The resistance is suitable as a direct measure of the level. (DG) [de

  17. Aquatic assessment of the Ely Copper Mine Superfund site, Vershire, Vermont

    Science.gov (United States)

    Seal, Robert R.; Kiah, Richard G.; Piatak, Nadine M.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Argue, Denise M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.

    2010-01-01

    The Ely Mine, which operated from 1821 to 1905, and its area of downstream impact constitute the Ely Copper Mine Superfund site. The site was placed on the National Priorities List in 2001. The mine comprises underground workings, foundations from historical structures, several waste-rock piles, roast beds associated with the smelting operation, and slag piles resulting from the smelting. The mine site is drained by Ely Brook, which includes several tributaries, one of which drains a series of six ponds. Ely Brook empties into Schoolhouse Brook, which flows 3.3 kilometers and joins the Ompompanoosuc River.

  18. Assessment of primary production in a eutrophic lake from carbon and nitrogen isotope ratios of a carnivorous fish

    International Nuclear Information System (INIS)

    Yoshioka, Takahito

    1991-01-01

    The carbon and nitrogen isotope ratios of Hypomesus transpacificus (a pond smelt) in a eutrophic lake, Lake Suwa, were measured from April to September in 1986 and 1987. The differences in the isotope ratios between these two years were observed. The stable isotopes were transferred from phytoplankton to zooplankton and pond smelt, associated with organic matters. Therefore, the difference in the isotope ratios in two years seemed to reflect the differences of the proceeding of primary production. It was suggested that the carbon and nitrogen isotope ratios of animal, whose trophic level is far from primary producer, can be the qualitative indicators for assessing the primary production in a lake ecosystem. (author)

  19. Studying properties of carbonaceous reducers and process of forming primary titanium slags

    Directory of Open Access Journals (Sweden)

    T. K. Balgabekov

    2014-10-01

    Full Text Available When smelting a rich titanium slag the most suitable are low-ash reducers, and the studies revealed the suitability for this purpose of special coke and coal. An important property of a reducer is its specific resistance. Therefore there were carried out studies for measuring electric resistance of briquettes consisting of ilmenite concentrate and different carbonaceous reducers. It is recommended to jointly smelt the briquetted and powdered burden (the amount of the powdered burden varies form 20 tо 50 %, this leads to the increase of technical-economic indicators of the process.

  20. Fish larvae in Bahía Sebastián Vizcaíno and the adjacent oceanic region, Baja California, México.

    Directory of Open Access Journals (Sweden)

    Jiménez–Rosenberg, S. P. A.

    2007-01-01

    Full Text Available The taxonomic composition of the fish larvae assemblage of Bahía Sebastián Vizcaíno and the adjacentoceanic region is presented based on oblique zooplankton hauls made during 12 oceanographic surveys between fall1997 and fall 2000. In total, 186 taxa representing 71 families were collected. Myctophidae, Phosichthyidae, andEngraulidae were the most abundant during winter and Myctophidae, Merlucciidae, and Bathylagidae during spring. Insummer and fall Phosichthyidae and Myctophidae were the most abundant. During 1999 and 2000, seasonal variabilitywas identified in the area by the fish larvae composition, defining winter and fall as a low diversity period and springand summer as a high diversity period. Interannual variability was detected with an El Niño event, with higher larvalabundances of tropical and subtropical taxa, and a La Niña event, with high abundances of larvae of Engraulis mordax.

  1. A new species of nectar-feeding bat, genus Lonchophylla, from western Colombia and western Ecuador (Mammalia: Chiroptera: Phyllostomidae)

    Science.gov (United States)

    Woodman, N.

    2007-01-01

    The twelve recognized species of nectar-feeding bats of the genus Lonchophylla occur in low- and middle-elevation, humid, Neotropical forests. Morphological and morphometrical analyses of specimens formerly lumped with Lonchophylla mordax O. Thomas (1903) support recognition of Lonchophylla concava Goldman (1914) as a separate species and reveal a third species from the western Pacific lowlands of Colombia and Ecuador that I describe herein as Lonchophylla jornicata. This new species is morphologically similar to Lonchophylla concava but is distinctively larger than that species. Tests for sexual dimorphism within these and other species of Lonchophyllini suggest a tendency for females to have slightly longer, narrower skulls, higher coronoid processes of the mandible, and longer forearms than males.

  2. The spider collection (Arachnida: Araneae of the Zoological Museum of the Iranian Research Institute of Plant Protection, with new species records for Iran

    Directory of Open Access Journals (Sweden)

    Zamani, Alireza

    2015-11-01

    Full Text Available The spider collection of the Zoological Museum of the Iranian Research Institute of Plant Protection was studied during the summer of 2014. A total of 180 specimens, belonging to 25 families, 60 genera and 77 species were documented. Of these, the following nine species could be recorded from Iran for the first time: Alopecosa schmidti (Hahn, 1835, Anyphaena accentuata (Walckenaer, 1802, Crustulina sticta (O. P.-Cambridge, 1861, Enoplognatha mordax (Thorell, 1875, Ero tuberculata (De Geer, 1778, Salticus zebraneus (C. L. Koch, 1837, Pardosa aenigmatica Tongiorgi, 1966, Pardosa nebulosa (Thorell, 1872 and Tmarus piochardi (Simon, 1866. Morphological and geographical data are provided for the newly recorded species. Two species (P. aenigmatica and T. piochardi are illustrated and a map of localities is given.

  3. 40 CFR 424.23 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Science.gov (United States)

    2010-07-01

    ... representing the degree of effluent reduction attainable by the application of the best available technology economically achievable. 424.23 Section 424.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Furnaces and Other Smelting Operations With Wet Air Pollution Control Devices Subcategory § 424.23 Effluent...

  4. 40 CFR 424.27 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Science.gov (United States)

    2010-07-01

    ... control technology. 424.27 Section 424.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Furnaces and Other Smelting Operations With Wet Air Pollution Control Devices Subcategory § 424.27 Effluent... conventional pollutant control technology. Except as provided in §§ 125.30 through 125.32, any existing point...

  5. 40 CFR 424.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Science.gov (United States)

    2010-07-01

    ... technology currently available. 424.22 Section 424.22 Protection of Environment ENVIRONMENTAL PROTECTION... Covered Electric Furnaces and Other Smelting Operations With Wet Air Pollution Control Devices Subcategory... application of the best practicable control technology currently available. Except as provided in §§ 125.30...

  6. An assessment of common atmospheric particulate matter sampling ...

    African Journals Online (AJOL)

    USER

    The first factor, which accounts for 40% of the variance contained Al, Mg, K, Na and Pb, with high loadings of Mg and K. The composition of this factor suggests road or soil dust and biomass burning as the sources of PM10. The second factor contained Mn, Zn and Ni, which suggests metal smelting as a source at site C. The.

  7. 75 FR 28820 - Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response, Compensation...

    Science.gov (United States)

    2010-05-24

    ... (``CERCLA''), 42 U.S.C. 9607(a)(3), for response costs incurred by the Environmental Protection Agency..., Inc. associated with costs incurred by EPA at the Pioneer Smelting Superfund Site. The Department of... (25 cents per page reproduction cost) payable to the U.S. Treasury or, if by e-mail or fax, forward a...

  8. 75 FR 32503 - Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response Compensation...

    Science.gov (United States)

    2010-06-08

    ... Liability Act (``CERCLA''), 42 U.S.C. 9607(a)(2), for response costs incurred by the Environmental... any claim the United States has associated with costs incurred by EPA at the Pioneer Smelting... of $7.75 (25 cents per page reproduction cost) payable to the U.S. Treasury or, if by e-mail or fax...

  9. Solutions for Northern Kosovo: Lessons Learned in Mostar, Eastern Slavonia, and Brcko

    Science.gov (United States)

    2006-08-01

    with up to 20,000 jobs dependent on a large complex that included extraction, flotation , smelting, and downstream processing processes. The mines...with Serbia, no one option will serve as the silver bullet for all interested parties. Partition. Kosovo is legally still part of Serbia, although

  10. Conductivity as an indicator of surface water quality in the proximity ...

    African Journals Online (AJOL)

    2015-10-05

    Oct 5, 2015 ... FeCr smelting did not significantly impact surface water quality, but that surface run-off and/or groundwater leaching ... (EIAs) were required, or for older FeCr smelters during the .... then used for the determination of conductivity with a Hanna ... significant differences in the conductivity values measured at.

  11. Health status within the precincts of a nickel-copper mining and ...

    African Journals Online (AJOL)

    Background: Mining and smelting activities affect the biophysical environment and human health. Objective: This paper elucidates on the human health ... Fumes, vibrations, noise and constant movement of heavy equipment were considered as disturbing factors affecting health. Conclusion: Fumes of SO2 emanating from ...

  12. Development of technology of complex aluminum-silicon-chrome alloy with utilization of off grade raw materials

    Directory of Open Access Journals (Sweden)

    A. Mekhtiev

    2015-01-01

    Full Text Available Experimental studies on obtaining a complex aluminum-silicon-chrome alloy (FASCh from Karaganda high-ash coals and high-carbon ferrochromefines were carried out. A method for smelting low-carbon ferrochrome using aluminum-silicon-chrome alloy as a reductant is suggested.

  13. Performance of a Zerovalent Iron Reactive Barrier for the Treatment of Arsenic in Groundwater: Part 2. Geochemical Modeling and Solid Phase Studies

    Science.gov (United States)

    Arsenic uptake processes were evaluated in a zerovalent iron reactive barrier installed at a lead smelting facility using geochemical modeling, solid-phase analysis, and X-ray absorption spectroscopy techniques. Aqueous speciation of arsenic plays a key role in directing arsenic...

  14. Heavy metals content in reproductive organs of small mammals inhabiting in condition of chronic chemical exposure

    International Nuclear Information System (INIS)

    Mukhacheva, S.V.; Davydova, Yu.A.

    2008-01-01

    In this research by example of bank vole the heavy metals concentrations (cadmium, copper and zinc) in reproductive organs of small mammals inhabiting in condition of environmental pollution with wastes from copper-smelting industry have been considered. The levels of radionuclides accumulation in testes, seminal vesicle and ovaries of voles with radionuclide concentration in others organs and tissues of animals have been compared.

  15. Phytoremediation and phytomining: Using plants to remediate contaminated or mineralized environments

    Science.gov (United States)

    One type of harsh environment for plants is metal and metalloid contaminated or mineralized soils which exist in most countries due to geological formations or to the history of mining and smelting. Depending on soil pH and fertility, metal-rich soils may be barren and eroding into wider areas. Some...

  16. Relationship between the standing vegetation, soil properties and ...

    African Journals Online (AJOL)

    This study assessed the floristic composition, soil properties and the soil seedbank of the vegetation around the Iron smelting factory. This was with a view to determining the functional role played by soil chemical composition and the seed bank in the modifications of vegetation patterns. Five 100 m × 5 m plots were ...

  17. Sweating Like a Pig: Physics or Irony?

    Science.gov (United States)

    Bohren, Craig F.

    2016-01-01

    In his interesting and informative book "Is That a Fact?," Joe Schwarcz avers that pigs do not sweat and the saying "sweating like a pig" originates in iron smelting. Oblong pieces of hot iron, with a fancied resemblance to a sow with piglets, cool in sand to the dew point of the surrounding air, and hence water condenses on…

  18. Onderzoek aan spiering als oorzaak van het voorkomen van groepsgewijs vissende meeuwen in de Waddenzee, met systematische en populatie-dynamische gegevens over de spiering

    NARCIS (Netherlands)

    Krijgsman, J.A.

    1971-01-01

    From 1-8-70 till 31-3-71 research was done on the cause of the phenomenon of fishing seagulls taking place in the Wadden Sea and on the systematic and population-dynamic aspects of the smelt from the Wadden Sea and the Ysel Lake. The phenomenon of fishing in groups of the black-headed gull, turned

  19. Seasonal variation of mercury vapor concentrations in industrial ...

    African Journals Online (AJOL)

    Mercury has been known as a toxic substance that could raise potential risks to human health. The main anthropogenic sources of mercury pollution in air include combustion of fossil fuel, metal smelting and processing, and vehicle transportation all of which exist in Ahvaz city in Southwestern Iran. Ambient air mercury ...

  20. Titanium ; dream new material

    International Nuclear Information System (INIS)

    Lee, Yong Tae; Kim Seung Eon; Heoon, Yong Taek; Jung, Hui Won

    2001-11-01

    The contents of this book are history of Titanium, present situation of Titanium industry, property of Titanium alloy, types of it, development of new alloy of Titanium smelting of Titanium, cast of Titanium and heat treatment of Titanium, Titanium alloy for plane, car parts, biological health care, and sport leisure and daily life, prospect, and Titanium industrial development of Titanium in China.

  1. 77 FR 19755 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List the San...

    Science.gov (United States)

    2012-04-02

    ... movement of longfin smelt into the ocean or deeper water habitat in summer months is at least partly a...] TP02AP12.000 The origin and geomorphology of West Coast estuaries result from geologic forces driven by...-767). Major classifications of estuaries include fjord, drowned-river valley, lagoon, and bar-built...

  2. MINE WASTE TECHNOLOGY PROGRAM; PHOSPHATE STABILIZATION OF HEAVY METALS CONTAMINATED MINE WASTE YARD SOILS, JOPLIN, MISSOURI NPL SITE

    Science.gov (United States)

    This document summarizes the results of Mine Waste Technology Project 22-Phosphate Stabilization of Heavy Metals-Contaminated Mine Waste Yard Soils. Mining, milling, and smelting of ores near Joplin, Missouri, have resulted in heavy metal contamination of the area. The Joplin s...

  3. Reactive power compensation and loss reduction in large industrial enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, S; Gajic, B; Mijailovic, S [Institute Nikola Tesla, Beograd (Yugoslavia)

    1991-12-01

    This paper considers the reactive power compensation and the active power and energy loss reduction of large radial power networks in the Serbian mine and smelting industry. It gives an efficient optimization procedure for positioning and sizing capacitors in large industrial systems integrated with a simple network analysis method. (Author).

  4. 77 FR 41075 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2012-07-12

    ... Decorative Chromium Electroplating and Chromium Anodizing Tanks. O Ethylene Oxide X X X X X Sterilization... Operations. KK Printing and X X X X X Publishing Industry. LL Primary Aluminum X X X Reduction Plants. MM... X X Production. QQQ Primary Copper X X X X Smelting. RRR Secondary X X X X Aluminum Production. TTT...

  5. Manganese exposure in foundry furnacemen and scrap recycling workers

    DEFF Research Database (Denmark)

    Lander, F; Kristiansen, J; Lauritsen, Jens

    1999-01-01

    Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system, where it may cause a neurological disorder...

  6. Assessment of energy requirements in proven and new copper processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pitt, C.H.; Wadsworth, M.E.

    1980-12-31

    Energy requirements are presented for thirteen pyrometallurgical and eight hydrometallurgical processes for the production of copper. Front end processing, mining, mineral processing, gas cleaning, and acid plant as well as mass balances are included. Conventional reverberatory smelting is used as a basis for comparison. Recommendations for needed process research in copper production are presented.

  7. Mineralogy of Tailings Dump around Selebi Phikwe Nickel-Copper ...

    African Journals Online (AJOL)

    This study aimed at mineralogically characterizing the tailings dump emanating from the mining and smelting of nickel-copper (Ni-Cu) at Selebi Phikwe, Botswana, Southern Africa. Samples of tailings dump around the Selebi Phikwe Ni-Cu plant were studied using petrographic microscopy and X-ray Powder Diffraction ...

  8. Browse Title Index

    African Journals Online (AJOL)

    Items 151 - 200 of 524 ... Vol 18, No 4 (2016), Development of human PBBK models for mixtures: Binary ... study of an iron and steel smelting industry, Lagos, Nigeria, Abstract PDF ... Vol 16, No 3 (2014), Effect of selected factors on the current flow and voltage ... Vol 14, No 2 (2012), Effects of nutrient and light stress on some ...

  9. Op een kaal plein valt niets te kiezen (Interview)

    NARCIS (Netherlands)

    Boo, de M.; Lenzholzer, S.

    2010-01-01

    Pleinen en straten worden geteisterd door gure windvlagen of je smelt juist weg als de zon flink schijnt. In haar proefschrift legt Sanda Lenzholzer uit dat ontwerpers meer rekening moeten houden met het microklimaat in de stad. Dat houdt ook de aso’s op afstand.

  10. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    International Nuclear Information System (INIS)

    Smith, K.P.; Blunt, D.L.; Williams, G.P.; Tebes, C.L.

    1995-01-01

    A preliminary radiological dose assessment related to equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials in production waste streams. The assessment evaluated the relative dose of these activities and included a sensitivity analysis of certain input parameters. Future studies and potential policy actions are recommended

  11. Differences in antimony and arsenic releases from lead smelter fly ash in soils

    Czech Academy of Sciences Publication Activity Database

    Ettler, V.; Mihaljevič, M.; Šebek, O.; Valigurova, R.; Klementová, Mariana

    2012-01-01

    Roč. 72, Supp. 4 (2012), s. 15-22 ISSN 0009-2819 Institutional research plan: CEZ:AV0Z40320502 Keywords : Antimony * Arsenic * Lead smelting * Fly ash * Soil * Mobility Subject RIV: CA - Inorganic Chemistry Impact factor: 1.351, year: 2012

  12. Hyperaccumulation of zinc by Corydalis davidii in Zn-polluted soils.

    Science.gov (United States)

    Lin, Wenjie; Xiao, Tangfu; Wu, Yunying; Ao, Ziqiang; Ning, Zengping

    2012-02-01

    A field survey was conducted to identify potential Zn accumulators from an artisanal Zn smelting area in southwest China's Guizhou Province. Hydroponic and soil culture experiments were performed to investigate the accumulation ability of Zn in Corydalis davidii. Zn concentrations in roots, stems and leaves of C. davidii in the smelting site were 1.1-3.5, 1.2-11.2, and 3.3-14 mg g(-)(1), respectively, whereas Zn concentrations in roots, stems and leaves of C. davidii in the contaminated site impacted by the Zn smelting were 1.0-2.4, 1.9-6.5, and 3.0-1.1 mg g(-1), respectively. Zn concentrations in leaves and stems of C. davidii were observed at above 10 mg g(-1) that refers to the threshold of Zn hyperaccumulator. The concentration distribution of Zn in C. davidii was leaf>stem>root, and the Zn bioaccumulation factors of C. davidii were above 1. It is concluded that C. davidii has high tolerance to concentrate Zn stress, and that C. davidii is a newly discovered Zn-hyperaccumulator with high biomass in the aboveground parts. Based on the cultivation experiments, C. davidii could reduce Zn concentration by 26.6, 21.2, and 10.2 mg kg(-1)yr(-1) by phytoextraction from the smelting slag, Zn-contaminated soil, and background soil, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Brown Rockfish, Copper Rockfish, and Black Rockfish

    Science.gov (United States)

    1989-09-01

    years (430 mm). 1977). Adults usually remain in one Females may mature at 5 years area, but may travel more than 600 km (300 mm); all are mature by 11...and Miller is primarily pelagic nekton (smelt, 1982). anchovies) and zooplankton such as salps , mysids, and crab megalops Parasites include leeches

  14. CONTROL ALGORITMS OF BOF MELTING WITH CONSIDERING THE INFLUENCE OF UNCONTROLLED DISTURBANCE

    Directory of Open Access Journals (Sweden)

    V. S. Bogushevsky

    2016-01-01

    Full Text Available The article describes influence of uncontrollable disturbances for output parameters of converting smelting. You also find numerical values of impact impurity of scrap, falling mixer slag with cast iron, limestone instead of lime and water from cooled elements on decarbonization, bathtub temperature and slag basicity. Created a control algorithm with the influence of uncontrolled disturbance.

  15. The study of high-boron steel and high-boron cast iron used for shield

    International Nuclear Information System (INIS)

    Pan Xuerong; Lu Jixin; Wen Yaozeng; Wang Zhaishu; Cheng Jiantin; Cheng Wen; Shun Danqi; Yu Jinmu

    1996-12-01

    The smelting, forging, heat-treatment technology and the mechanical properties of three kinds of high-boron steels (type 1: 0.5% boron; type 2: 0.5% boron and 4% or 2% nickel; type 3: 0.5% boron, 0.5% nickel and 0.5% molybdenum) were studied. The test results show that the technology for smelting, forging and heat-treatment (1050 degree C/0.5 h water cooled + 810 degree C/1 h oil cooled) in laboratory is feasible. Being sensitive to notch, the impact toughness of high-boron steel type 1 is not steady and can not meet the technology requirements on mechanical properties. The mechanical properties of both high-boron steel type 2 and type 3 can meet the technological requirements. The smelting technology of high-boron casting iron containing 0.5% boron was researched. The tests show that this casting iron can be smelted in laboratory and its properties can basically satisfy the technology requirements. (10 refs., 6 figs., 11 tab.)

  16. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker a...

  17. Field Operations and Enforcement Manual for Air Pollution Control. Volume III: Inspection Procedures for Specific Industries.

    Science.gov (United States)

    Weisburd, Melvin I.

    The Field Operations and Enforcement Manual for Air Pollution Control, Volume III, explains in detail the following: inspection procedures for specific sources, kraft pulp mills, animal rendering, steel mill furnaces, coking operations, petroleum refineries, chemical plants, non-ferrous smelting and refining, foundries, cement plants, aluminum…

  18. 78 FR 29292 - Partial Approval and Partial Disapproval of Air Quality State Implementation Plans; Arizona...

    Science.gov (United States)

    2013-05-20

    ... Smelter, American Smelting and Refining Company (ASARCO) Hayden Smelter, Catalyst Paper, and Arizona... Smelter, ASARCO Hayden Smelter, Catalyst Paper, and AEPCO Apache Generating Station. In summary, we propose to approve a revised set of BART-eligible units for the Miami and Hayden smelters; the State's...

  19. Sectoral linkage analysis of three main air pollutants in China's industry: Comparing 2010 with 2002.

    Science.gov (United States)

    He, Weiwei; Wang, Yuan; Zuo, Jian; Luo, Yincheng

    2017-11-01

    To investigate the driving forces of air pollution in China, the changes in linkages amongst inter-industrial air pollutant emissions were analyzed by hypothetical extraction method under the input-output framework. Results showed that the emissions of SO 2 , soot and dust from industrial sources increased by 56.46%, 36.95% and 11.69% respectively in 2010, compared with 2002. As major contributors to emissions, the power and gas sectors were responsible for the growing SO 2 emissions, the nonmetal products sector for soot emissions, and the metals mining, smelting and pressing sectors for dust emissions. The increasing volume of emissions was mainly driven by the growing demand in the transport equipment and electrical equipment sectors. In addition, the expansion in the metals mining, smelting and pressing sectors could result in even more severe air pollution. Therefore, potential effective strategies to control air pollution in China are: (1) reducing the demand of major import sectors in the equipment manufacturing industry; (2) promoting R&D in low-emissions-production technologies to the power and gas sectors, the metals mining, smelting and pressing sectors, and the nonmetal products sector, and (3) auditing the considerable industrial scale expansion in the metals mining, smelting and pressing sectors and optimizing the industrial structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. International Annual Conference (29th) of ICT Held in Karlsruhe, Federal Republic of Germany on June 30-July 3, 1998. Energetic Materials; Production, Processing and Characterization

    Science.gov (United States)

    1998-06-26

    QCPE 464, M. Dewar Group, University of Texas, Austin, Texas, 78712. 10. Allen F.H., Brice M.D., Cartwright B.A., Doubleday A., Higgs T., Hummelink T...steel and fusions of Fe- C-Ni. The usage of the materials smelted with addition of ultra-dispersive powders of boson carbide, vanadium carbide and

  1. Degree of susceptibility of industrial gases of tree and shrub species

    Energy Technology Data Exchange (ETDEWEB)

    Dobrovoljskii, I A

    1952-01-01

    The trees and shrubs of the iron smelting region of Krivoi Rog, in the Ukraine, were surveyed to determine susceptibility to air pollution damage. Most of the observations were made in parks and green belts in industrial areas. A classification of tree and shrub species is presented; they are separated into three classes according to their susceptibility to air pollutant injury.

  2. REFINEMENT AND GRANULATING OF COHERENT-GRANULAR MATERIALS IN MACHINES OF ROLL TYPE

    Directory of Open Access Journals (Sweden)

    E. B. Lozhechnikov

    2006-01-01

    Full Text Available The way of selective break of heterogeneous compositions, in particular slags of copper-smelting production and also granular metal-containing powder materials, is based and developed. Calibration of the rolls, providing contrilled granulating of metal-containing powders by rolling.

  3. 40 CFR 63.547 - Test methods.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Test methods. 63.547 Section 63.547... Hazardous Air Pollutants from Secondary Lead Smelting § 63.547 Test methods. (a) The following test methods...), and 63.545(e): (1) Method 1 shall be used to select the sampling port location and the number of...

  4. 40 CFR 63.1546 - Test methods.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Test methods. 63.1546 Section 63.1546... Hazardous Air Pollutants for Primary Lead Smelting § 63.1546 Test methods. (a) The following procedure shall....1543(a)(1) through § 63.1543(a)(9) shall be determined according to the following test methods in...

  5. 76 FR 73658 - Notice of Intent to Repatriate Cultural Items: Tennessee Valley Authority and the University of...

    Science.gov (United States)

    2011-11-29

    ...; six shell pendants; three pieces of glass; three samples of red ochre; three mink skull fragments; one... made from iron, brass, pewter, silver and lead; three glass mirrors or mirror fragments; six glass... piece of smelted lead; four steatite pipes; one catlinite pipe; two clay siltstone pipes; three...

  6. Omaha Soil Mixing Study: Redistribution of Lead in Remediated Residential Soils Due to Excavation or Homeowner Disturbance.

    Science.gov (United States)

    Urban soils within the Omaha Lead Superfund Site have been contaminated with lead (Pb) from atmospheric deposition of particulate materials from lead smelting and recycling activities. In May of 2009 the Final Record of Decision stated that any residential soil exceeding the pre...

  7. Inert Anode Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1999-07-01

    This ASME report provides a broad assessment of open literature and patents that exist in the area of inert anodes and their related cathode systems and cell designs, technologies that are relevant for the advanced smelting of aluminum. The report also discusses the opportunities, barriers, and issues associated with these technologies from a technical, environmental, and economic viewpoint.

  8. [CHEMICAL AIR POLLUTION OF THE OCCUPATIONAL ENVIRONMENT AS A FACTOR FOR PROFESSIONAL RISK FOR WORKERS OF MAIN OCCUPATIONS IN THE COPPER AND NICKEL METALLURGY].

    Science.gov (United States)

    Lipatov, G Ia; Adrianovskiĭ, V I; Gogoleva, O I

    2015-01-01

    There are presented the results of hygienic researches of the harmful substances content in the air of the working area ofthe copper and nickel metallurgy. Sulfur-containing gases (primarily sulfur dioxide), to the effects of which there are exposed workers of drying, smelting, converter conversion, are shown to play a leading role among professional factors.

  9. A millennium of metallurgy recorded by lake sediments from Morococha, Peruvian Andes.

    Science.gov (United States)

    Cooke, Colin A; Abbott, Mark B; Wolfe, Alexander P; Kittleson, John L

    2007-05-15

    To date, information concerning pre-Colonial metallurgy in South America has largely been limited to the archaeological record of artifacts. Here, we reconstruct a millennium of smelting activity in the Peruvian Andes using the lake-sediment stratigraphy of atmospherically derived metals (Pb, Zn, Cu, Ag, Sb, Bi, and Ti) and lead isotopic ratios (206Pb/ 207Pb) associated with smelting from the Morococha mining region in the central Peruvian Andes. The earliest evidence for metallurgy occurs ca. 1000 A.D., coinciding with the fall of the Wari Empire and decentralization of local populations. Smelting during this interval appears to have been aimed at copper and copper alloys, because of large increases in Zn and Cu relative to Pb. A subsequent switch to silver metallurgy under Inca control (ca. 1450 to conquest, 1533 A.D.) is indicated by increases in Pb, Sb, and Bi, a conclusion supported by further increases of these metals during Colonial mining, which targeted silver extraction. Rapid development of the central Andes during the 20th century raised metal burdens by an order of magnitude above previous levels. Our results represent the first evidence for pre-Colonial smelting in the central Peruvian Andes, and corroborate the sensitivity of lake sediments to pre-Colonial metallurgical activity suggested by earlier findings from Bolivia.

  10. An Ancient Inca Tax and Metallurgy in Peru

    Science.gov (United States)

    Journal of Chemical Education, 2007

    2007-01-01

    The discovery of ancient Inca tax rulers and other metallurgical objects in Peru show that the ancient civilizations of the country smelted metals. The analysis shows that the smelters in Peru switched from the production of copper to silver after a tax was imposed on them by the Inca rulers.

  11. Reactivity of fly ash from copper smelters in an Oxisol: implications for smelter-polluted soil systems in the tropics

    Czech Academy of Sciences Publication Activity Database

    Ettler, V.; Petráňová, Veronika; Vítková, M.; Mihaljevič, M.; Šebek, O.; Kříbek, B.

    2016-01-01

    Roč. 16, č. 1 (2016), s. 115-124 ISSN 1439-0108 Institutional support: RVO:68378297 Keywords : cobalt * copper * fly ash * leaching * Oxisol * smelting Subject RIV: DD - Geochemistry Impact factor: 2.522, year: 2016 http://link.springer.com/article/10.1007%2Fs11368-015-1174-7

  12. Assessment of toxicity of heavy metal contaminated soils for Collembola in the field and laboratory

    DEFF Research Database (Denmark)

    Xu, Jie; Krogh, Paul Henning; Luo, Yongming

    2008-01-01

    We present a field and laboratory investigation of effects of increasing levels of heavy metal contamination on the biodiversity and performance of collembolans. A 40 year old pollution with Cu, Zn, Pb and Cd pollution due to Cu smelting over 40 years was investigated in a paddy field area of Zhe...

  13. Research On Technology Of Making Rare Earth Alloy Having Rare Earth Content ≽30% From Ore (≽40% REO) Using Aluminum Thermal Technology In Arc Furnace

    International Nuclear Information System (INIS)

    Ngo Xuan Hung; Ngo Trong Hiep; Tran Duy Hai; Nguyen Huu Phuc

    2014-01-01

    Arc furnace was used to smelt materials consisting of rare earth ore having rare earth content of ≽40% REO, aluminum as the reducing agent and additives. Rare earth alloy was obtained with rare earth metal content of more than 30%. (author)

  14. Author Details

    African Journals Online (AJOL)

    Olaniyi, HB. Vol 9, No 1 (2007) - Articles An Application Of Receptor Modeling To Identify Airborne Particulate Sources In Lagos, Nigeria Abstract PDF · Vol 13, No 1 (2011) - Articles Mass and energy audit in a Nigerian iron and steel smelting factory: An operational and efficiency study. Abstract PDF · Vol 14, No 1 (2012) - ...

  15. 40 CFR 63.542 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... chute or hopper located at the ends of the dryer. Electric furnace means a smelting furnace consisting of a vessel into which reverberatory furnace slag is introduced and that uses electrical energy to..., agglomerating furnaces, and drying kiln transition pieces. Refining kettle means an open-top vessel that is...

  16. The vertical distribution of fish in the open water area of a deep temperate mesotrophic lake assessed by hydroacoustics and midwater trawling

    Czech Academy of Sciences Publication Activity Database

    Jůza, Tomáš; Frouzová, Jaroslava; Brämick, U.; Draštík, Vladislav; Mrkvička, Tomáš; Kubečka, Jan

    2012-01-01

    Roč. 97, č. 6 (2012), s. 509-525 ISSN 1434-2944 R&D Projects: GA AV ČR(CZ) IAA600960901 Institutional support: RVO:60077344 Keywords : smelt * vendace * trawling * hydroacoustics * Lake Werbellin Subject RIV: EH - Ecology, Behaviour Impact factor: 0.870, year: 2012

  17. Occurrence of parasites of the genus Eustrongylides spp. (Nematoda: Dioctophymatidae in fish caught in Trasimeno lake, Italy

    Directory of Open Access Journals (Sweden)

    Raffaella Branciari

    2016-11-01

    Full Text Available Eustrongylides spp. is considered a freshwater fish zoonotic nematode. In the present study, the prevalence of Eustrongylides spp. in six edible fish (European perch - Perca fluviatilis, goldfish - Carassius auratus, largemouth black bass - Micropterus salmoides, tench- Tinca tinca, carp - Cyprinus carpio and sand smelt - Atherina boyeri of Trasimeno lake was surveyed. The investigations were conducted from October 2014 to September 2015 and 384 specimens per species for each season were caught in Trasimeno lake and examined for the presence of larvae in the abdominal cavity and muscle. The presence of nematodes in the abdominal cavity and musculature was revealed in three fish species. The prevalence of Eustrongylides spp. infection was 6.84, 1.89 and 0.13% in perch, largemouth black bass and sand smelt, respectively. The number of parasites per fish was only one in largemouth black bass and sand smelt and ranged from one up to three in perch. This study states that the European perch, largemouth black bass and sand smelt of Trasimeno lake are infected with zoonotic parasites; therefore, food business operators have to take appropriate measures to guarantee the health of consumers.

  18. ENERGY ASPECTS OF STEELMAKING SLAGS APPLICATION IN METALLURGY

    Directory of Open Access Journals (Sweden)

    V. L. Naydek

    2013-01-01

    Full Text Available A comparative assessment of energy intensity of converter steel production in different types of smelting with slag processing in the ladle was made. Analysis of the data shows that the use of liquid steel slag in steel production for its refining saves about 2.2 GJ or 75 kg of coal equivalent for each ton of metal.

  19. Unusual conservation of mitochondrial gene order in Crassostrea oysters: evidence for recent speciation in Asia

    Science.gov (United States)

    2010-01-01

    Background Oysters are morphologically plastic and hence difficult subjects for taxonomic and evolutionary studies. It is long been suspected, based on the extraordinary species diversity observed, that Asia Pacific is the epicenter of oyster speciation. To understand the species diversity and its evolutionary history, we collected five Crassostrea species from Asia and sequenced their complete mitochondrial (mt) genomes in addition to two newly released Asian oysters (C. iredalei and Saccostrea mordax) for a comprehensive analysis. Results The six Asian Crassostrea mt genomes ranged from 18,226 to 22,446 bp in size, and all coded for 39 genes (12 proteins, 2 rRNAs and 25 tRNAs) on the same strand. Their genomes contained a split of the rrnL gene and duplication of trnM, trnK and trnQ genes. They shared the same gene order that differed from an Atlantic sister species by as many as nine tRNA changes (6 transpositions and 3 duplications) and even differed significantly from S. mordax in protein-coding genes. Phylogenetic analysis indicates that the six Asian Crassostrea species emerged between 3 and 43 Myr ago, while the Atlantic species evolved 83 Myr ago. Conclusions The complete conservation of gene order in the six Asian Crassostrea species over 43 Myr is highly unusual given the remarkable rate of rearrangements in their sister species and other bivalves. It provides strong evidence for the recent speciation of the six Crassostrea species in Asia. It further indicates that changes in mt gene order may not be strictly a function of time but subject to other constraints that are presently not well understood. PMID:21189147

  20. Incongruence between morphotypes and genetically delimited species in the coral genus Stylophora: phenotypic plasticity, morphological convergence, morphological stasis or interspecific hybridization?

    Directory of Open Access Journals (Sweden)

    Flot Jean-François

    2011-10-01

    Full Text Available Abstract Background Morphological data suggest that, unlike most other groups of marine organisms, scleractinian corals of the genus Stylophora are more diverse in the western Indian Ocean and in the Red Sea than in the central Indo-Pacific. However, the morphology of corals is often a poor predictor of their actual biodiversity: hence, we conducted a genetic survey of Stylophora corals collected in Madagascar, Okinawa, the Philippines and New Caledonia in an attempt to find out the true number of species in these various locations. Results A molecular phylogenetic analysis of the mitochondrial ORF and putative control region concurs with a haploweb analysis of nuclear ITS2 sequences in delimiting three species among our dataset: species A and B are found in Madagascar whereas species C occurs in Okinawa, the Philippines and New Caledonia. Comparison of ITS1 sequences from these three species with data available online suggests that species C is also found on the Great Barrier Reef, in Malaysia, in the South China Sea and in Taiwan, and that a distinct species D occurs in the Red Sea. Shallow-water morphs of species A correspond to the morphological description of Stylophora madagascarensis, species B presents the morphology of Stylophora mordax, whereas species C comprises various morphotypes including Stylophora pistillata and Stylophora mordax. Conclusions Genetic analysis of the coral genus Stylophora reveals species boundaries that are not congruent with morphological traits. Of the four hypotheses that may explain such discrepancy (phenotypic plasticity, morphological stasis, morphological convergence, and interspecific hybridization, the first two appear likely to play a role but the fourth one is rejected since mitochondrial and nuclear markers yield congruent species delimitations. The position of the root in our molecular phylogenies suggests that the center of origin of Stylophora is located in the western Indian Ocean, which probably

  1. Phenological and distributional shifts in ichthyoplankton associated with recent warming in the northeast Pacific Ocean.

    Science.gov (United States)

    Auth, Toby D; Daly, Elizabeth A; Brodeur, Richard D; Fisher, Jennifer L

    2018-01-01

    Understanding changes in the migratory and reproductive phenology of fish stocks in relation to climate change is critical for accurate ecosystem-based fisheries management. Relocation and changes in timing of reproduction can have dramatic effects upon the success of fish populations and throughout the food web. During anomalously warm conditions (1-4°C above normal) in the northeast Pacific Ocean during 2015-2016, we documented shifts in timing and spawning location of several pelagic fish stocks based on larval fish samples. Total larval concentrations in the northern California Current (NCC) during winter (January-March) 2015 and 2016 were the highest observed since annual collections first occurred in 1998, primarily due to increased abundances of Engraulis mordax (northern anchovy) and Sardinops sagax (Pacific sardine) larvae, which are normally summer spawning species in this region. Sardinops sagax and Merluccius productus (Pacific hake) exhibited an unprecedented early and northward spawning expansion during 2015-16. In addition, spawning duration was greatly increased for E. mordax, as the presence of larvae was observed throughout the majority of 2015-16, indicating prolonged and nearly continuous spawning of adults throughout the warm period. Larvae from all three of these species have never before been collected in the NCC as early in the year. In addition, other southern species were collected in the NCC during this period. This suggests that the spawning phenology and distribution of several ecologically and commercially important fish species dramatically and rapidly changed in response to the warming conditions occurring in 2014-2016, and could be an indication of future conditions under projected climate change. Changes in spawning timing and poleward migration of fish populations due to warmer ocean conditions or global climate change will negatively impact areas that were historically dependent on these fish, and change the food web structure

  2. Geochemical position of Pb, Zn and Cd in soils near the Olkusz mine/smelter, South Poland: effects of land use, type of contamination and distance from pollution source.

    Science.gov (United States)

    Chrastný, Vladislav; Vaněk, Aleš; Teper, Leslaw; Cabala, Jerzy; Procházka, Jan; Pechar, Libor; Drahota, Petr; Penížek, Vít; Komárek, Michael; Novák, Martin

    2012-04-01

    The soils adjacent to an area of historical mining, ore processing and smelting activities reflects the historical background and a mixing of recent contamination sources. The main anthropogenic sources of metals can be connected with historical and recent mine wastes, direct atmospheric deposition from mining and smelting processes and dust particles originating from open tailings ponds. Contaminated agriculture and forest soil samples with mining and smelting related pollutants were collected at different distances from the source of emission in the Pb-Zn-Ag mining area near Olkusz, Upper Silesia to (a) compare the chemical speciation of metals in agriculture and forest soils situated at the same distance from the point source of pollution (paired sampling design), (b) to evaluate the relationship between the distance from the polluter and the retention of the metals in the soil, (c) to describe mineralogy transformation of anthropogenic soil particles in the soils, and (d) to assess the effect of deposited fly ash vs. dumped mining/smelting waste on the mobility and bioavailability of metals in the soil. Forest soils are much more affected with smelting processes than agriculture soils. However, agriculture soils suffer from the downward metal migration more than the forest soils. The maximum concentrations of Pb, Zn, and Cd were detected in a forest soil profile near the smelter and reached about 25 g kg(- 1), 20 g kg(- 1) and 200 mg kg(- 1) for Pb, Zn and Cd, respectively. The metal pollutants from smelting processes are less stable under slightly alkaline soil pH then acidic due to the metal carbonates precipitation. Metal mobility ranges in the studied forest soils are as follows: Pb > Zn ≈ Cd for relatively circum-neutral soil pH (near the smelter), Cd > Zn > Pb for acidic soils (further from the smelter). Under relatively comparable pH conditions, the main soil properties influencing metal migration are total organic carbon and cation exchange

  3. Effects of prey abundance, distribution, visual contrast and morphology on selection by a pelagic piscivore

    Science.gov (United States)

    Hansen, Adam G.; Beauchamp, David A.

    2014-01-01

    Most predators eat only a subset of possible prey. However, studies evaluating diet selection rarely measure prey availability in a manner that accounts for temporal–spatial overlap with predators, the sensory mechanisms employed to detect prey, and constraints on prey capture.We evaluated the diet selection of cutthroat trout (Oncorhynchus clarkii) feeding on a diverse planktivore assemblage in Lake Washington to test the hypothesis that the diet selection of piscivores would reflect random (opportunistic) as opposed to non-random (targeted) feeding, after accounting for predator–prey overlap, visual detection and capture constraints.Diets of cutthroat trout were sampled in autumn 2005, when the abundance of transparent, age-0 longfin smelt (Spirinchus thaleichthys) was low, and 2006, when the abundance of smelt was nearly seven times higher. Diet selection was evaluated separately using depth-integrated and depth-specific (accounted for predator–prey overlap) prey abundance. The abundance of different prey was then adjusted for differences in detectability and vulnerability to predation to see whether these factors could explain diet selection.In 2005, cutthroat trout fed non-randomly by selecting against the smaller, transparent age-0 longfin smelt, but for the larger age-1 longfin smelt. After adjusting prey abundance for visual detection and capture, cutthroat trout fed randomly. In 2006, depth-integrated and depth-specific abundance explained the diets of cutthroat trout well, indicating random feeding. Feeding became non-random after adjusting for visual detection and capture. Cutthroat trout selected strongly for age-0 longfin smelt, but against similar sized threespine stickleback (Gasterosteus aculeatus) and larger age-1 longfin smelt in 2006. Overlap with juvenile sockeye salmon (O. nerka) was minimal in both years, and sockeye salmon were rare in the diets of cutthroat trout.The direction of the shift between random and non-random selection

  4. Foraging and metabolic consequences of semi-anadromy for an endangered estuarine fish.

    Directory of Open Access Journals (Sweden)

    Bruce G Hammock

    Full Text Available Diadromy affords fish access to productive ecosystems, increasing growth and ultimately fitness, but it is unclear whether these advantages persist for species migrating within highly altered habitat. Here, we compared the foraging success of wild Delta Smelt-an endangered, zooplanktivorous, annual, semi-anadromous fish that is endemic to the highly altered San Francisco Estuary (SFE-collected from freshwater (<0.55 psu and brackish habitat (≥0.55 psu. Stomach fullness, averaged across three generations of wild Delta Smelt sampled from juvenile through adult life stages (n = 1,318, was 1.5-fold higher in brackish than in freshwater habitat. However, salinity and season interacted, with higher fullness (1.7-fold in freshwater than in brackish habitat in summer, but far higher fullness in brackish than freshwater habitat during fall/winter and winter/spring (1.8 and 2.0-fold, respectively. To examine potential causes of this interaction we compared mesozooplankton abundance, collected concurrently with the Delta Smelt, in freshwater and brackish habitat during summer and fall/winter, and the metabolic rate of sub-adult Delta Smelt acclimated to salinities of 0.4, 2.0, and 12.0 psu in a laboratory experiment. A seasonal peak in mesozooplankton density coincided with the summer peak in Delta Smelt foraging success in freshwater, and a pronounced decline in freshwater mesozooplankton abundance in the fall coincided with declining stomach fullness, which persisted for the remainder of the year (fall, winter and spring. In brackish habitat, greater foraging 'efficiency' (prey items in stomachs/mesozooplankton abundance led to more prey items per fish and generally higher stomach fullness (i.e., a higher proportion of mesozooplankton detected in concurrent trawls were eaten by fish in brackish habitat. Delta Smelt exhibited no difference in metabolic rate across the three salinities, indicating that metabolic responses to salinity are unlikely to have

  5. Synthesis of studies in the fall low-salinity zone of the San Francisco Estuary, September-December 2011

    Science.gov (United States)

    Brown, Larry R.; Baxter, Randall; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven; Erickson, Gregg; Feyrer, Frederick; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce; Kirsch, Joseph; Mueller-Solger, Anke; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Van Nieuwenhuyse, Erwin

    2014-01-01

    In fall 2011, a large-scale investigation (fall low-salinity habitat investigation) was implemented by the Bureau of Reclamation in cooperation with the Interagency Ecological Program to explore hypotheses about the ecological role of low-salinity habitat in the San Francisco Estuary—specifically, hypotheses about the importance of fall low-salinity habitat to the biology of delta smelt Hypomesus transpacificus, a species endemic to the San Francisco Estuary and listed as threatened or endangered under federal and state endangered species legislation. The Interagency Ecological Program is a consortium of 10 agencies that work together to develop a better understanding of the ecology of the Estuary and the effects of the State Water Project and Federal Central Valley Project operations on the physical, chemical, and biological conditions of the San Francisco Estuary. The fall low-salinity habitat investigation constitutes one of the actions stipulated in the Reasonable and Prudent Alternative issued with the 2008 Biological Opinion of the U.S. Fish and Wildlife Service, which called for adaptive management of fall Sacramento-San Joaquin Delta outflow following “wet” and “above normal” water years to alleviate jeopardy to delta smelt and adverse modification of delta smelt critical habitat. The basic hypothesis of the adaptive management of fall low-salinity habitat is that greater outflows move the low-salinity zone (salinity 1–6), an important component of delta smelt habitat, westward and that moving the low-salinity zone westward of its position in the fall of recent years will benefit delta smelt, although the specific mechanisms providing such benefit are uncertain. An adaptive management plan was prepared to guide implementation of the adaptive management of fall low-salinity habitat and to reduce uncertainty. This report has three major objectives:

  6. One-Step Extraction of Antimony in Low Temperature from Stibnite Concentrate Using Iron Oxide as Sulfur-Fixing Agent

    Directory of Open Access Journals (Sweden)

    Yun Li

    2016-07-01

    Full Text Available A new process for one-step extraction of antimony in low temperature from stibnite concentrate by reductive sulfur-fixation smelting in sodium molten salt, using iron oxide as sulfur-fixing agent, was presented. The influences of molten salt addition and composition, ferric oxide dosage, smelting temperature and duration on extraction efficiency of antimony were investigated in details, respectively. The optimum conditions were determined as follows: 1.0 time stoichiometric requirement (α of mixed sodium salt (αsalt = 1.0, WNaCl:Wsalt = 40%, αFe2O3 = 1.0, Wcoke:Wstibnite = 40%, where W represents weight, smelting at 850 °C (1123 K for 60 min. Under the optimum conditions, the direct recovery rate of antimony can reach 91.48%, and crude antimony with a purity of 96.00% has been achieved. 95.31% of sulfur is fixed in form of FeS in the presence of iron oxide. Meanwhile, precious metals contained in stibnite concentrate are enriched and recovered comprehensively in crude antimony. In comparison to traditional antimony pyrometallurgical process, the smelting temperature of present process is reduced from 1150–1200 °C (1423–1473 K to 850–900 °C (1123–1173 K. Sulfur obtained in stibnite is fixed in FeS which avoids SO2 emission owing to the sulfur-fixing agent. Sodium salt can be regenerated and recycled in smelting system when the molten slag is operated to filter solid residue. The solid residue is subjected to mineral dressing operation to obtain iron sulfide concentrate which can be sold directly or roasted to regenerate into iron oxide.

  7. Prospects for separating heavy metal from contaminated soil

    International Nuclear Information System (INIS)

    Langen, M.; Hoberg, H.; Hamacher, B.

    1994-01-01

    For decades, large quantities of organic and inorganic pollutants have been brought into the soil as a result of the industrial operations of smelting and coking plants. This paper reports on the prospects of separating heavy metals from soil contaminated by smelting and coking plants by means of a physical/chemical washing procedure. Besides the description of virgin soil characteristics, cleaning results and process parameters of calssification, density separation and flotation processes are presented. It is shown that heavy metal pollution of virgin soil can be reduced by the classical process stages of soil washing. The metal content of virgin soil are critically assessed whereby the limits of the physical-chimical washing process will also be entered into. Emphasis is placed on the significance of the determination of limiting values for inorganic contamination, especially for soil contaminated with both organic and inorganic pollution. (orig.) [de

  8. Analysis on environmental impact of radiation from metallurgical project for rare metals

    International Nuclear Information System (INIS)

    Xia Zitong; Zhang Baozeng

    2012-01-01

    Rare metals are the composition of many high-property metal materials, which has a wide range of uses in the field of national defense advanced science technology. Since Ta-Nb material is associated radioactive mineral resources, and it contains high radionuclide, resulting in some radioactive indicators in process and workplace of the Ta-Nb smelting projects were significantly higher than that of the surrounding environmental radiation background. Based on the analysis of Ta-Nb smelting projects, the major sources of pollution were identified. and the possible radiation impact of the project was analyzed and evaluated, corrective measures on the process layout were also proposed, and reasonable suggestions of how to optimize the radiation protection were made. (authors)

  9. Replication of an ivg protocol to estimate bioaccessible arsenic in materials from a gold mining area in Brazil

    Directory of Open Access Journals (Sweden)

    Fábio Benedito Ono

    2012-08-01

    Full Text Available Tests for bioaccessibility are useful in human health risk assessment. No research data with the objective of determining bioaccessible arsenic (As in areas affected by gold mining and smelting activities have been published so far in Brazil. Samples were collected from four areas: a private natural land reserve of Cerrado; mine tailings; overburden; and refuse from gold smelting of a mining company in Paracatu, Minas Gerais. The total, bioaccessible and Mehlich-1-extractable As levels were determined. Based on the reproducibility and the accuracy/precision of the in vitro gastrointestinal (IVG determination method of bioaccessible As in the reference material NIST 2710, it was concluded that this procedure is adequate to determine bioaccessible As in soil and tailing samples from gold mining areas in Brazil. All samples from the studied mining area contained low percentages of bioaccessible As.

  10. The ground stone assemblage of a metal workers community: An unexplored dimension of Iron Age copper production at Timna

    Directory of Open Access Journals (Sweden)

    Aaron Greener

    2016-10-01

    In the framework of the renewed excavations at several of the copper smelting sites at Timna, a pioneering study was conducted in which more than 1000 ground stone tools were identified and registered. These tools include, among others, grinding stones, pounders, anvils and mortars; most were manufactured of compacted sandstone and granite, exposed in several locations in the valley. In this paper we present a typology and quantitative analysis of the ground stone tools which were used by the metal workers, and offer an interpretation of how the various types of tools were employed as part of the copper production process. This provides new insights regarding the smelting process and the conditions needed for its successful outcome.

  11. Suitability of non-energy GHGs for emissions trading

    International Nuclear Information System (INIS)

    Haites, E.; Proestos, A.

    2000-01-01

    This paper assesses the suitability of different sources of non-energy greenhouse gases for emissions trading. Different forms of emissions trading are defined and criteria for determining whether a source is suitable for emissions trading are proposed. The suitability for emissions trading is assessed for: methane (CH4) from oil and gas production; CH4 from coal mines; CH4 from landfills; CH4 from wastewater treatment; CH4 from enteric fermentation; CH4 from livestock manure, nitrous oxide (N2O) from adipic acid production; N2O from fertilizer use; N2O from nitric acid production, carbon dioxide (CO2) and perfluorocarbons (PFCs) from aluminum smelting; sulphur hexafluoride (SF6) from magnesium smelting and die casting; HFCs from HCFC production, other uses of SF6, PFCs and hydrofluorocarbons (HFCs); CO2 from ammonia production; lime and cement production, and iron ore reduction

  12. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Dady B. Dadyburjor; Mark E. Heavner; Manoj Katakdaunde; Liviu Magean; J. Joshua Maybury; Alfred H. Stiller; Joseph M. Stoffa; John W. Zondlo

    2006-08-01

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques.

  13. Some peculiarities of fish abundance, species and sizes distribution, and spacing

    International Nuclear Information System (INIS)

    Astrauskas, A.; Bernotas, E.; Jovaisha, R.

    1995-01-01

    During the construction and exploitation process of Ignalina NPP the abundance of fishes has dropped, and especially stenothermic species (smelt and vendace). The general increase of fish abundance is observed in recent years (1992-1994). This is linked with changes of fish species and their adaptation to the new environmental conditions. Now the partial renovation of vendace abundance is observed, too. It is a result of free feeding recess coming out as the smelt dramatically decreased. Before now the ecosystem of the lake is greatly disbalanced due to antropogenetic impact of the NPP. It's partial stabilisation (but on the essentially high level) is possible only in some generations of fish living in the lake. (author). 18 refs., 1 tab., 11 figs

  14. Production of Green Steel from Red Mud: A Novel Concept

    Science.gov (United States)

    Bhoi, Bhagyadhar; Behera, Pravas Ranjan; Mishra, Chitta Ranjan

    Red mud of Indian origin contains around 55% plus of Fe2O3 and is considered as a hazardous waste for the alumina industry. For production of one tone of alumina employing the Bayer's Process, around two tones of red mud is generated from three tones of Bauxite. Conventional process of steel making is not devoid of environmental pollution. In the present investigation, efforts have been made to produce steel from red mud by adopting reduction roasting, magnetic separation and hydrogen plasma smelting route. Magnetic fraction, containing enriched iron oxide and minimal content of alumina, is produced following the first two stages which is then subjected to hydrogen plasma smelting process for production of steel. This novel concept follows a green path way for production of steel free from pollution and is termed as green steel. Further, the only by-product that is produced in the process, is water, which is eco-friendly and recyclable.

  15. A procedure for the production of steel exhibiting a low specific activity of gamma emitters

    International Nuclear Information System (INIS)

    Dolenek, J.; Raska, P.; Kodrle, L. et al.

    1989-01-01

    Steel exhibiting low specific gamma activity can be obtained from a metallic charge containing liquid and solid pig iron produced from ores, sinters, coke, limestone and other components. This charge is worked up in a metallurgical fining unit using predetermined amounts of slag-forming substances such as lime, limestone and dolomite; fining ore can also be present. The smelt must be kept in constant motion. The pig iron smelt for the production of this steel contains 0.1-1.1% Si and 0.1-1.0% Mn. All equipment with which the charge and steel will come in contact must be free from remains of previous productions and, preferrably, fitted with new lining. This concerns runners, pig iron transportation mixers, ladles and the production unit. (P.A.)

  16. Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

    International Nuclear Information System (INIS)

    Wang, X.Y.; Zhang, Z.S.; Bai, T.

    2010-01-01

    The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

  17. Radioactive contamination of recycled metals

    International Nuclear Information System (INIS)

    Lubenau, J.O.; Cool, D.A.; Yusko, J.G.

    1996-01-01

    Radioactive sources commingled with metal scrap have become a major problem for the metals recycling industry worldwide. Worldwide there have been 38 confirmed reports of radioactive sources accidentally smelted with recycled metal. In some instances, contaminated metal products were subsequently distributed. The metal mills, their products and byproducts from the metal making process such as slags, crosses and dusts from furnaces can become contaminated. In the U.S., imported ferrous metal products such as reinforcement bars, pipe flanges, table legs and fencing components have been found contaminated with taco. U.S. steel mills have unintentionally smelted radioactive sources on 16 occasions. The resulting cost for decontamination waste disposal and temporary closure of the steel mill is typically USD 10,000,000 and has been as much as USD 23,000,000. Other metal recycling industries that have been affected by this problem include aluminum, copper, zinc, gold, lead and vanadium. (author)

  18. Rapid Analysis of Copper Ore in Pre-Smelter Head Flow Slurry by Portable X-ray Fluorescence.

    Science.gov (United States)

    Burnett, Brandon J; Lawrence, Neil J; Abourahma, Jehad N; Walker, Edward B

    2016-05-01

    Copper laden ore is often concentrated using flotation. Before the head flow slurry can be smelted, it is important to know the concentration of copper and contaminants. The concentration of copper and other elements fluctuate significantly in the head flow, often requiring modification of the concentrations in the slurry prior to smelting. A rapid, real-time analytical method is needed to support on-site optimization of the smelter feedstock. A portable, handheld X-ray fluorescence spectrometer was utilized to determine the copper concentration in a head flow suspension at the slurry origin. The method requires only seconds and is reliable for copper concentrations of 2.0-25%, typically encountered in such slurries. © The Author(s) 2016.

  19. Numerical Simulation of High Frequency Induction Heating for the Design of a Casting Furnace

    International Nuclear Information System (INIS)

    Lee, Hye Jin; Lee, Yoon Sang; Yang, Jae Ho; Park, Jong Man

    2010-01-01

    Induction heating is used for various applications of the industrial manufacturing process. It provides various heat treatments such as hardening, melting, casting and so on. Induction heating is a complex process coupling the electromagnetic and thermal phenomena. In this process an alternating electric current induces electromagnetic field, which in turn induces eddy currents in the workpiece. The induced eddy currents release energy in the form of heat, which is then distributed throughout the workpiece. In this paper, the electromagnetic and thermal coupling analysis was performed by the 3 dimensional finite elements program, OPERA 3D. For convenience of calculation, a steady-state was assumed. Based on materials composing a real smelting furnace, testing the distribution of eddy current from each material and its final temperature value, we found out which material has advantage in the temperature variations among suggested materials, and confirmed which material is suitable to composing smelting furnace

  20. The story of global patent inventions

    International Nuclear Information System (INIS)

    Wang, Yeun Jung

    1996-11-01

    This book introduces the global patent inventions, which are soap floating on the water, computer, radar, zipper, fuel cell, a raincoat, a pencil, a ball point pen, vitamin, an ice saw, a subway, post it, endoscope, ultrasonic detector, machine to pierce the hall, hair-restorer, a refrigerator, tricycle tractor of Benz steam engine of watt, carburettor, aluminum smelting process, video game, ice cream freezer, lead powder, piling system, burner using infrared rays, small projector, blender for recycling of resource, and artificial silk.

  1. The story of global patent inventions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yeun Jung

    1996-11-15

    This book introduces the global patent inventions, which are soap floating on the water, computer, radar, zipper, fuel cell, a raincoat, a pencil, a ball point pen, vitamin, an ice saw, a subway, post it, endoscope, ultrasonic detector, machine to pierce the hall, hair-restorer, a refrigerator, tricycle tractor of Benz steam engine of watt, carburettor, aluminum smelting process, video game, ice cream freezer, lead powder, piling system, burner using infrared rays, small projector, blender for recycling of resource, and artificial silk.

  2. Managing water to protect fish: A review of California's environmental water account, 2001-2005

    Science.gov (United States)

    Brown, L.R.; Kimmerer, W.; Brown, R.

    2009-01-01

    The Sacramento-San Joaquin Delta, the landward reach of the San Francisco Estuary, provides habitat for threatened delta smelt, endangered winter-run Chinook salmon, and other species of concern. It is also the location of huge freshwater diversion facilities that entrain large numbers of fish. Reducing the entrainment of listed fishes into these facilities has required curtailment of pumping, reducing the reliability of water deliveries. We reviewed the first 5 years (2001-2005) of the Environmental Water Account (EWA), a program instituted to resolve conflicts between protecting listed fishes and providing a reliable water supply. The EWA provided fishery agencies with control over 0.2-0.4 km3 of water to be used for fish protection at no cost to users of exported water, and fish agencies guaranteed no disruption of water supply for fish protection. The EWA was successful in reducing uncertainty in water supply; however, its contribution to the recovery of listed fishes was unclear. We estimated the effectiveness of the EWA to be modest, increasing the survival of winter-run Chinook salmon by 0-6% (dependent on prescreen mortality), adult delta smelt by 0-1%, and juvenile delta smelt by 2-4%. Allocating EWA water for a single life stage of one species could provide larger gains in survival. An optimally allocated EWA of equal size to the median of the first 5 years could increase abundance of juvenile delta smelt up to 7% in the springs of dry years. If the EWA is to become a long-term program, estimates of efficacy should be refined. If the program is to be held accountable for quantitative increases in fish populations, it will be necessary to integrate scientific, possibly experimental, approaches. ?? 2008 Springer Science+Business Media, LLC.

  3. Glass-crystalline materials for active waste incorporation

    International Nuclear Information System (INIS)

    Kulichenko, V.V.; Krylova, N.V.; Vlasov, V.I.; Polyakov, A.S.

    1979-01-01

    This paper presents the results of investigations into the possibility and conditions for using glass-crystalline materials for the incorporation of radionuclides. Materials of a cast pyroxene type that are obtained by smelting calcined wastes with acid blast furnace slags are described. A study was also made of materials of a basalt type prepared from wastes with and without alkali metal salt. Changes in the structure and properties of materials in the process of storage at different temperatures have been studied

  4. Extractive metallurgy. Recent advances

    International Nuclear Information System (INIS)

    Stevenson, E.J.

    1977-01-01

    Detailed technical information derived from patents issued since 1975 on extractive metallurgy is presented. In part one, concerning copper, the major areas covered are: smelting and roasting; acid leaching; ammonia leach processes; cuprous chloride and ferric chloride; and recovery of copper values from solution. Part two covers other metals, including: nickel and cobalt; ocean floor nodules; lead, zinc, molybdenum and manganese; precious metals; and uranium titanium, tantalum, rhenium, gallium, and other metals

  5. Coal gold agglomeration: an innovative approach to the recovery of gold in environmentally sensitive areas

    Energy Technology Data Exchange (ETDEWEB)

    Wall, N.C.; Hughes-Narborough, C.; Willey, G. [Davy (Stockton) Ltd., Stockton-on-Tees (United Kingdom)

    1994-11-01

    Coal Gold Agglomeration (CGA) was developed by BP Minerals and involves the selective recovery of oleophilic gold particles from an aqueous slurry into coal-oil agglomerates. These agglomerates are allowed to build up to a high gold loading and are then separated from the slurry. The loaded agglomerates are burned and the gold is finally recovered from the ash residue by dissolution and precipitation or by direct smelting. 6 figs.

  6. Processing precious metals in a top-blown rotary converter

    Science.gov (United States)

    Whellock, John G.; Matousek, Jan W.

    1990-09-01

    Copper-nickel/platinum-palladium flotation concentrates produced by the Stillwater Mining Company were smelted and refined in an integrated pilot plant consisting of a submerged-arc electric furnace and top-blown rotary converter. The conversion of high-iron electric furnace mattes was achieved with apparent oxygen efficiencies in excess of 100 percent. Platinum and palladium recoveries averaged 99 percent, and copper and nickel recoveries were 94 percent.

  7. Effects of Aroclor 1242 and different fish-based diets on vitamins A(retinol) and A2 (3,4-didehydroretinol), and their fatty acyl esters in mink plasma

    International Nuclear Information System (INIS)

    Kaekelae, Anne; Kaekelae, Reijo; Hyvaerinen Heikki; Nieminen, Petteri

    2003-01-01

    The effects of a 21-week exposure to Aroclor 1242 (1 mg per day in feed on plasma concentrations of vitamins A 1 (retinol) and A(3,4-didehydroretinol) and their principal fatty acyl esters (A 1 -16:0 A 2 -16:0 (palmitates), A 1 -18:1n-9; A 2 -18:1n-9 (oleates), and A 1 -18:0 A 2 -18:0 (stearates)) were studied in young female mink (Mustela vison) fed a diet based on freshwater smelt. These vitamin levels were also examined in mink fed diets containing Baltic herring or fatty marine fish. In the Aroclor-exposed smelt-fed mink, the plasma concentrations of A 1 and Aesters were significantly lower than the levels in controls fed the uncontaminated smelt diet. In addition, the A 2 esters reacted mor sensitively to the polychlorinated biphenyls than did A 1 esters. I contrast, in the plasma of the exposed mink the level of alcoholic A 1 was normal, and transport of thyroxine (T 4 ) and nonspecific lipoprotei transport of major lipids were not impaired. Despite the large dietary supply of vitamin A 2 and high levels of plasma A 2 esters, the mink fed freshwate smelt had only trace amounts of alcoholic vitamin A 2 in their plasma. The concentrations of A 1 and A 2 esters in the plasma of all the mink studied correlated with the hepatic total concentrations of the vitamins. Thus, in carnivores that have nonspecific lipoprotein transport of vitamin A esters determination of plasma levels of the esterified vitamins may be a useful nondestructive way to estimate stores of the vitamin A analogs in the body and to assess the organochlorine-induced decrease in the vitamin stores

  8. Content of Cu, Zn, As and other elements in some plants and soils on heaps and in areas of air pollution sources

    Energy Technology Data Exchange (ETDEWEB)

    Banasova, V; Hajduk, J

    1975-01-01

    The authors studied the content of Cu, Fe, Zn in the soils and plants on heaps after mining of copper at Slovinky (5 km south of Krompachy), and in some other areas in the west part of the Low Tatra Mts, and the content of As, Zn, Cu, S, Mg, Ca in the soil and the plants influenced by emissions from copper smelting works in Krompachy. 31 references.

  9. Distribución de selenio, cobalto,molibdeno y cadmio en el proceso de fundición de cobre bajo recirculación de polvos

    Directory of Open Access Journals (Sweden)

    Montenegro, V.

    2008-06-01

    Full Text Available Usually dust generated from copper smelting in Chile contains high concentrations of copper and arsenic, but also other metals of considerable value and some environmental interest such as selenium, cobalt and molybdenum. It is desirable to understand the behavior of those elements when the smelting process operates with dust recirculation. In this study, the effect of dust recirculation to smelting process on the distribution among the matte, slag and gas phases were evaluated as a function of matte grade, amount of recirculated dust, oxygen enrichment and temperature. Experimental results show that selenium can be concentrated at high matte grade ranges and high oxygen enrichments in blowing gas. However, the result suggested that high recirculation amounts to smelting process are not feasible because it increases the minor metal losses.

    Usualmente, el polvo generado durante el proceso de fundición de cobre en Chile, contiene altos contenidos de cobre y arsénico, pero también otros metales de considerable valor económico e interés medioambiental, como selenio, cobalto y molibdeno. Es deseable entender el comportamiento de estos elementos cuando el proceso opera con recirculación de polvos. En este estudio, el efecto de la recirculación de polvo al proceso de fusión de cobre en la distribución entre la mata, escoria y gas fue evaluado como una función del grado de la mata, cantidad de polvo recirculado, enriquecimiento de oxígeno y temperatura. Los resultados experimentales mostraron que el selenio puede ser concentrado a altos rangos de mata y altas concentraciones de oxígeno en el gas de soplado. Sin embargo, los resultados sugieren que altas cantidades de recirculación no son factibles debido a que aumentan la pérdida de elementos menores.

  10. Measurement of lead compound in stack gas

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Y; Hori, M; Tanikawa, N

    1979-01-01

    The concentration and particle-size distribution of lead compounds in the exhaust gas from various stationary sources are examined. The stationary sources concern lead production from battery scraps, lead smelting of cable mold, steel production from iron scraps, plastic combustion furnace, and a heavy oil boiler. A lead concentration of 0.2-100 mg/cu m in exhaust gas is detected. Furthermore, exhaust gas lead compounds are affected by the raw materials used.

  11. Determining the baking isotherm temperature of Söderberg electrodes and associated structural changes

    OpenAIRE

    Shoko, L.; Beukes, J.P.; Strydom, C.A.

    2013-01-01

    One of the most commonly employed electrode systems in industrial metal smelting applications is continuous self-baking electrodes, i.e. the Söderberg electrode system. In this system, the temperature at which transition from a liquid/soft paste to a solid carbonaceous electrode takes place is termed the baking isotherm temperature. This temperature is extremely important within the context of electrode management. In this paper, thermo mechanical analysis (TMA) was used to measure the dimens...

  12. Improvement in steel quality obtained by continuous casting by means of electrophysical influences

    International Nuclear Information System (INIS)

    Shklyar, V.; Garcia, L.; Formoso, A.; Cores, A.

    1998-01-01

    Laboratory tests with thin smelted in a crucible and industrial tests with crude steel poured in moulds had been carried out. These metals were subjected to electrophysical influences. As a results of the applied electric field, it is observed in tin that during solidification, the crystallization temperature and the solidification time are changed Crystal growth in the electric field direction and an increase of the fracture limit in the steel ingot are observed. (Author) 9 refs

  13. Soybean varieties as effective tool for phytoremediation of cadmium polluted soil

    OpenAIRE

    Mihajlov, Ljupco; Balabanova, Biljana; Zajkova-Paneva, Vesna; Wei, Shuhe

    2017-01-01

    Cadmium (Cd) is an important toxic heavy metal and the warning of health risks from Cd pollution were issued initially in the ‘70s. Increased concentrations of Cd in agricultural soils are known to come from human activities, such as the application of phosphate fertilizer, sewage sludge, wastewater, pesticides, mining and smelting of metalliferous ores with high Cd content, and traffic. Although there are many reports on Cd contamination in agricultural soils, most of the investigations are ...

  14. Assessments at multiple levels of biological organization allow for an integrative determination of physiological tolerances to turbidity in an endangered fish species

    OpenAIRE

    Hasenbein, Matthias; Fangue, Nann A.; Geist, Juergen; Komoroske, Lisa M.; Truong, Jennifer; McPherson, Rina; Connon, Richard E.

    2016-01-01

    Turbidity can influence trophic levels by altering species composition and can potentially affect fish feeding strategies and predator?prey interactions. The estuarine turbidity maximum, described as an area of increased suspended particles, phytoplankton and zooplankton, generally represents a zone with higher turbidity and enhanced food sources important for successful feeding and growth in many fish species. The delta smelt (Hypomesus transpacificus) is an endangered, pelagic fish species ...

  15. Seasonal fish and invertebrate communities in three northern California estuaries

    OpenAIRE

    Osborn, Katherine

    2017-01-01

    The majority of Northern California estuaries are small, flooded, river valleys that are largely unstudied due to their small sizes and remote locations. Yet these estuaries serve as important nursery areas for many marine fish species including rockfish, flatfish, smelt, and herring, and they are vital to anadromous species such as Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead (O. mykiss). I sampled the summer and winter fish and invertebrate communities of the Big, Mad, and Ten Mi...

  16. Scientific and technical problems in the production of coke

    Energy Technology Data Exchange (ETDEWEB)

    Glushchenko, I M

    1979-05-01

    This paper lists several scientific and technological problems facing the producers of coke in the future. The demand for coke on the world market is steadily increasing despite the efforts of metallurgists to find non-coke methods of ore smelting. The major problems are held to be the gap between very successful results of research and the lack of their application to industry, unsatisfactory coke oven construction, problems in quenching and imperfections in the formed coke process. (In Russian)

  17. The problems of high-nitrogen steels production

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Kaputkina, L.M.; Efimenko, S.P.

    1999-01-01

    Analysis of existing technologies of high-nitrogen steel production shows that rational nitrogen content in mass production corresponds to moderate high values. Such steels can be smelted under normal or slightly elevated pressure in steelmaking units, using processes of mass- and special metallurgy. High-nitrogen steels with ''overequilibrium'' nitrogen content are promising, but technology and equipment for production of them are complicated, and production of such steels is therefore limited. (orig.)

  18. Coupled Downscaled Climate Models and Ecophysiological Metrics Forecast Habitat Compression for an Endangered Estuarine Fish.

    Directory of Open Access Journals (Sweden)

    Larry R Brown

    Full Text Available Climate change is driving rapid changes in environmental conditions and affecting population and species' persistence across spatial and temporal scales. Integrating climate change assessments into biological resource management, such as conserving endangered species, is a substantial challenge, partly due to a mismatch between global climate forecasts and local or regional conservation planning. Here, we demonstrate how outputs of global climate change models can be downscaled to the watershed scale, and then coupled with ecophysiological metrics to assess climate change effects on organisms of conservation concern. We employed models to estimate future water temperatures (2010-2099 under several climate change scenarios within the large heterogeneous San Francisco Estuary. We then assessed the warming effects on the endangered, endemic Delta Smelt, Hypomesus transpacificus, by integrating localized projected water temperatures with thermal sensitivity metrics (tolerance, spawning and maturation windows, and sublethal stress thresholds across life stages. Lethal temperatures occurred under several scenarios, but sublethal effects resulting from chronic stressful temperatures were more common across the estuary (median >60 days above threshold for >50% locations by the end of the century. Behavioral avoidance of such stressful temperatures would make a large portion of the potential range of Delta Smelt unavailable during the summer and fall. Since Delta Smelt are not likely to migrate to other estuaries, these changes are likely to result in substantial habitat compression. Additionally, the Delta Smelt maturation window was shortened by 18-85 days, revealing cumulative effects of stressful summer and fall temperatures with early initiation of spring spawning that may negatively impact fitness. Our findings highlight the value of integrating sublethal thresholds, life history, and in situ thermal heterogeneity into global change impact

  19. Aplicación de la escoria de fundición de hierro como agregado en las mezclas de hormigón para pavimentos rígidos

    OpenAIRE

    Nasimba Chanataxi, Diego Andrés

    2017-01-01

    n this research article compares the resistance to compression and bending of a conventional concrete used for the construction of roads (rigid pavement), with a concrete that contains slag of iron smelting in partial replacement of the aggregate thickness (gravel) in percentages of 5%, 10%, 15%. With this objective, concrete mixtures and their respective cylindrical specimens and standard beams were elaborated to perform the corresponding compression and bending tests. It was concluded that ...

  20. Demand outlook for sulfur and high-sulfur petroleum coke

    Energy Technology Data Exchange (ETDEWEB)

    Koshkarov, V.Ya.; Danil' yan, P.G.; Feotov, V.E.; Gimaev, R.N.; Koshkarova, M.E.; Sadykova, S.R.; Vodovichenko, N.S.

    1980-01-01

    The feasibility of using sulfur and high-sulfur petroleum coke fines in pyrometallurgical processes and also in the chemical and coal-tar chemical industry is examined. Results of industrial tests on briquetting fines of petroleum coke with a petroleum binder are presented. The feasibility of using the obtained briquets in shaft furnace smelting of oxidized nickel ores, production of anode stock, and also in the chemical industry are demonstrated.

  1. A comparison of lead pollution record in Sphagnum peat with known historical Pb emission rates in the British isles and the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Novak, M.; Erel, Y.; Zemanova, L.; Bottrell, S.H.; Adamova, M. [Czech Geological Survey, Prague (Czech Republic)

    2008-12-15

    Vertical Pb concentration gradients and isotope ratios (Pb-206/Pb-207, Pb-208/Pb-207) are reported for five Pb-210-dated Sphagnum peat profiles. The studied peat bogs are in the British Isles (Thorne Moors, England; Mull, Scotland; and Connemara, Eire) and central Europe (Ocean, northern Czech Republic: Rybarenska slat, southern Czech Republic). Both the U.K. and the Czech Republic experienced maximum Pb emissions from Ag-Pb smelting around 1880. Pb emissions from coal burning peaked in 1955 in the U.K, and in the 1980s in the Czech Republic. In both countries, use of alkyl-lead additives to gasoline resulted in large Pb emissions between 1950 and 2000. We hypothesized that peaks in Pb emissions from smelting, coal burning and gasoline burning, respectively, should be mirrored in the peat profiles. However, a more complicated pattern emerged. Maximum annual Pb accumulation rates occurred in 1870 at Ocean, 1940 at Thorne Moors, 1988 at Rybarenska slat, and 1990 at Mull and Connemara. Atmospheric Pb inputs decreased in the order Thorne Moors {ge} Ocean > Rybarenska slat > Mull > Connemara. The Ocean bog was unique in the central European region in that its maximum Pb pollution dated back to the 19th century and coincided with maximum Pb smelting at Freiberg and Pribram. In contrast, numerous previously studied sites showed no Pb accumulation maximum in the 19th century, but increasing pollution until the 1980s. It remains unclear why Ocean did not record the regional peak in Pb emissions caused by high coal and gasoline burning around 1980, while an array of nearby bogs studied previously did record the 1980 coal/gasoline peak, but no 1880 smelting peak. Mean Pb-206/Pb-207 ratios of potential pollution sources were 1.07 and 1.11 for gasoline, 1.17 and 1.17 for local ores, and 1.18 and 1.19 for coal in the U.K. and the Czech Republic, respectively.

  2. Statistical modeling to management and treatment of scrap with low and very low residual activity

    International Nuclear Information System (INIS)

    Garcia-Bermejo Fernandez, R.; Anaya Lazaro, M.

    2011-01-01

    The experience of recent years on the management of scrap metal containing residual activity have allowed the development of a simple statistical model for the management of these materials. This statistical model includes a breakdown of the various processing operations to which these materials undergo and the effects in the process of radiological controls associated to the control of declassification that defines disposal (recycled by smelting, reclamation, temporary storage the plant or sent to final storage of radioactive waste.

  3. Introduction of Mercury-free Gold Extraction Methods to Medium-Scale Miners and Education of Health Care Providers to Reduce the use of Mercury in Sorata, Bolivia

    Directory of Open Access Journals (Sweden)

    Peter W. U. Appel

    2015-01-01

    Conclusions. The gold ores tested during the project proved amenable to mercury-free gold extraction using borax smelting. The miners also realized that gold recovery increased when performing mercury-free gold extraction. The miners decided to stop using mercury and a follow-up project cleaned their mining equipment for mercury and modified the processing lines. The health care providers were also successfully trained.

  4. Description of Latvian Metal Production and Processing Enterprises' Air Emissions

    OpenAIRE

    Pubule, J; Zahare, D; Blumberga, D

    2010-01-01

    The metal production and processing sector in Latvia has acquired a stable position in the national economy. Smelting of ferrous and nonferrous metals, production of metalware, galvanisation, etc. are developed in Latvia. The metal production and processing sector has an impact on air quality due to polluting substances which are released in the air from metal treatment processes. Therefore it is necessary to determine the total volume of emissions produced by the metal production and process...

  5. Statistical modeling to management and treatment of scrap with low and very low residual activity; Hacia la modelizacion estadistica de la gestion y tratamiento de chatarras con baja y muy bajo actividad residual

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Bermejo Fernandez, R.; Anaya Lazaro, M.

    2011-07-01

    The experience of recent years on the management of scrap metal containing residual activity have allowed the development of a simple statistical model for the management of these materials. This statistical model includes a breakdown of the various processing operations to which these materials undergo and the effects in the process of radiological controls associated to the control of declassification that defines disposal (recycled by smelting, reclamation, temporary storage the plant or sent to final storage of radioactive waste).

  6. THE DEVELOPMENT OF ENVIRONMENTAL MANAGEMENT SYSTEMS ON THE URALS INDUSTRIAL ENTERPRISES

    Directory of Open Access Journals (Sweden)

    L.A. Mochalova

    2008-12-01

    Full Text Available The article presents the results of analysis of introduction and development of environmental management systems on the Urals enterprises by mining and smelting industry which was conducted by questioning of their representatives. Object of the research were showing up of positive and negative features in construction of corporative environmental management systems according to recommendations of standards ISO 14000 and comparison of our and foreign experience.

  7. Wootz Crucible Steel: A Newly Discovered Production Site in South India

    OpenAIRE

    Sharad Srinivasan

    1994-01-01

    During the course of field investigations of copper mining and smelting in South India, the author of this paper came across a previously unrecorded archaeometallurgical site in Mel-siruvalur, South Arcot district, Tamil Nadu, which investigations have confinned was a production centre for wootz crucible steel in the Deccan. The find of this production centre supports the idea that wootz steel production was relatiYely widespread in South India, and extends the known horizons of this technolo...

  8. Results of the radiometric analysis: carried out on mineral samples of the company Funestano

    International Nuclear Information System (INIS)

    Alarcon, A.; Ramirez, M.; Iniguez, C.; Ergueta, V.; Velarde, Ch.A.

    1993-07-01

    A British based smelting company shipped 648 tons of mineral wastes to Bolivia for disposal. The environmental protection organization, Green Peace, publicly objected to the ground disposal at this waste. The representatives from this organization claimed that the mineral wastes contained toxic substances such as had sulfur and arsenic and also plutonium 210. This material was analysed for the presence of plutonium 210 using a gamma spectrometer. This report contains the test procedures used and the test results

  9. Processing of copper anodic-slimes for extraction of valuable metals.

    Science.gov (United States)

    Amer, A M

    2003-01-01

    This work focuses on processing of anodic slimes obtained from an Egyptian copper electrorefining plant. The anodic slimes are characterized by high concentrations of copper, lead, tin and silver. The proposed hydrometallurgical process consists of two leaching stages for the extraction of copper (H(2)SO(4)-O(2)) and silver (thiourea-Fe3+), and pyrometallurgical treatment of the remaining slimes for production of Pb-Sn soldering alloy. Factors affecting both the leaching and smelting stages were studied.

  10. Macroeconomic Consequences of Job Discrimination Against Women in Russia

    Science.gov (United States)

    2010-06-01

    departments (divisions) for the chlorination and rectification of titanium ore ( slag ) 184. Work performed by workers engaged in a department for the...separation and treatment of slag using the sublimation method in a fuming unit in the production of tin 185. Work performed by workers engaged in smelting...Condensator worker 192. Installer of reaction apparatus 193. Mercury separator 194. Furnaceman in production of zinc powder 195. Waelz furnace

  11. 2004 Top 10 Chinese Rare Earth Events

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1. Management to the Investment in Rare Earth IndustryConfirmedIn July 2004, "Decision on the Reform in Investment System" was formally publicized by the State Council of the People's Republic of China. The fifth item in the Decision stipulates that ore exploitation, smelting & separation and rare earth deep-processed projects with total investment over RMB¥100 million should be approved by the investment governing department of the State Council, and that other

  12. Population-level consequences of spatially heterogeneous exposure to heavy metals in soil: An individual-based model of springtails

    DEFF Research Database (Denmark)

    Meli, Mattia; Auclerc, Apolline; Palmqvist, Annemette

    2013-01-01

    Contamination of soil with toxic heavy metals poses a major threat to the environment and human health. Anthropogenic sources include smelting of ores, municipal wastes, fertilizers, and pesticides. In assessing soil quality and the environmental and ecological risk of contamination with heavy...... metals, often homogeneous contamination of the soil is assumed. However, soils are very heterogeneous environments. Consequently, both contamination and the response of soil organisms can be assumed to be heterogeneous. This might have consequences for the exposure of soil organisms...

  13. Plants as Useful Vectors to Reduce Environmental Toxic Arsenic Content

    OpenAIRE

    Nosheen Mirza; Qaisar Mahmood; Mohammad Maroof Shah; Arshid Pervez; Sikander Sultan

    2014-01-01

    Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, applica...

  14. FORMATION OF ORGANIZATIONAL AND ECONOMIC INTEGRATED STRUCTURES IN THE ALUMINUM INDUSTRY

    Directory of Open Access Journals (Sweden)

    S. B. Kazbekova

    2013-01-01

    Full Text Available The paper reveals the theoretical foundations of economic efficiency of production and integrated structures formation. Their advantages are demonstrated by the example of the formation of vertically integrated structures in the aluminium industry in the framework created by smelting aluminium cluster inKazakhstan. Also examines the valuable experience gained in the organization of such structures in theRussian Federationin recent years

  15. Coupled downscaled climate models and ecophysiological metrics forecast habitat compression for an endangered estuarine fish

    Science.gov (United States)

    Brown, Larry R.; Komoroske, Lisa M; Wagner, R Wayne; Morgan-King, Tara; May, Jason T.; Connon, Richard E; Fangue, Nann A.

    2016-01-01

    Climate change is driving rapid changes in environmental conditions and affecting population and species’ persistence across spatial and temporal scales. Integrating climate change assessments into biological resource management, such as conserving endangered species, is a substantial challenge, partly due to a mismatch between global climate forecasts and local or regional conservation planning. Here, we demonstrate how outputs of global climate change models can be downscaled to the watershed scale, and then coupled with ecophysiological metrics to assess climate change effects on organisms of conservation concern. We employed models to estimate future water temperatures (2010–2099) under several climate change scenarios within the large heterogeneous San Francisco Estuary. We then assessed the warming effects on the endangered, endemic Delta Smelt, Hypomesus transpacificus, by integrating localized projected water temperatures with thermal sensitivity metrics (tolerance, spawning and maturation windows, and sublethal stress thresholds) across life stages. Lethal temperatures occurred under several scenarios, but sublethal effects resulting from chronic stressful temperatures were more common across the estuary (median >60 days above threshold for >50% locations by the end of the century). Behavioral avoidance of such stressful temperatures would make a large portion of the potential range of Delta Smelt unavailable during the summer and fall. Since Delta Smelt are not likely to migrate to other estuaries, these changes are likely to result in substantial habitat compression. Additionally, the Delta Smelt maturation window was shortened by 18–85 days, revealing cumulative effects of stressful summer and fall temperatures with early initiation of spring spawning that may negatively impact fitness. Our findings highlight the value of integrating sublethal thresholds, life history, and in situ thermal heterogeneity into global change impact assessments. As

  16. Corrosion Resistant Coatings for High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Besman, T.M.; Cooley, K.M.; Haynes, J.A.; Lee, W.Y.; Vaubert, V.M.

    1998-12-01

    Efforts to increase efficiency of energy conversion devices have required their operation at ever higher temperatures. This will force the substitution of higher-temperature structural ceramics for lower temperature materials, largely metals. Yet, many of these ceramics will require protection from high temperature corrosion caused by combustion gases, atmospheric contaminants, or the operating medium. This paper discusses examples of the initial development of such coatings and materials for potential application in combustion, aluminum smelting, and other harsh environments.

  17. 40 CFR 421.254 - Standards of performance for new sources.

    Science.gov (United States)

    2010-07-01

    ... property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of silver... average mg/troy ounce of gold refined electrolytically Lead 5.544 2.574 Mercury 2.970 1.188 Silver 5.742 2...

  18. 40 CFR 421.256 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078... Maximum for monthly average mg/troy ounce of silver reduced in solution Lead 0.112 0.052 Mercury 0.060 0... for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically Lead 5.544 2...

  19. Report of the Defense Science Board 1980 Summer Study Panel on Industrial Responsiveness

    Science.gov (United States)

    1981-01-01

    incentives , as discussed earlier. They have "made-do" with obsolete and aging tools. The government machine tool base contains about 115,000 tools of...critical materials when the U.S has substantial dependence on imports. Under Title III the government can help establish or support mining and...INDUSTRIES CAN BE CHARACTERIZED INTO THREE SEGMENTS: 1. MINING 2. REFINING, SMELTING, AND SCRAP RECLAIMATION 3. FABRICATION BAUXITE MINING IS 95% OFF

  20. ENERGY SAVING TECHNOLOGY OF LIGATURES PRODUCTION ON THE BASIS OF MOLYBDENUM

    Directory of Open Access Journals (Sweden)

    A. G. Slutsky

    2014-01-01

    Full Text Available Data on development of technology of the molybdenum-containing addition alloy production by method of aluminothermic restoration is provided in the article. Influence of conditions of production on quality and metallurgical output of addition alloy is studied. The received addition alloys were tested in industrial conditions at smelting of the low-alloyed steel 35HML and the received results confirmed efficiency of application of the developed addition alloy.

  1. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker...... after an acute exposure to carbon monoxide. This complication was diagnosed by pure-tone audiometry and confirmed by transient evoked otoacoustic emissions. Hearing loss has not improved after 3 months of followup....

  2. A Brief History of Physics in China,

    Science.gov (United States)

    1982-07-29

    not attracted by magnets. Chang Hua noticed that a static charge was produced in combing hair and in undressing with silk and wool garments. He...after the expiration of the greenish white gas. It is at this moment that casting can be performed’. For the process of smelting and casting, since there...orange, then yellow, and appears white at about 1000°C. In the process of heating pottery and metals, the ancient Chinese mastered the knowledge of

  3. Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

    OpenAIRE

    L. Zhang; S. X. Wang; Q. R. Wu; F. Y. Wang; C.-J. Lin; L. M. Zhang; M. L. Hui; J. M. Hao

    2015-01-01

    Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, municipal solid waste incinerators, and biomass burning. Mercury in coal, ores and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C t...

  4. Description of 3,180 Courses of Chelation with Dimercaptosuccinic Acid in Children ≤5 y with Severe Lead Poisoning in Zamfara, Northern Nigeria: A Retrospective Analysis of Programme Data

    OpenAIRE

    Thurtle, Natalie; Greig, Jane; Cooney, Lauren; Amitai, Yona; Ariti, Cono; Brown, Mary Jean; Kosnett, Michael J.; Moussally, Krystel; Sani-Gwarzo, Nasir; Akpan, Henry; Shanks, Leslie; Dargan, Paul I.

    2014-01-01

    Editors' Summary Background Lead, a toxic metal that occurs naturally in the earth's crust, is now present throughout the environment because of human activities. For many years, lead was added to paint and gasoline and used in solder for water pipes. In addition, the mining, smelting, and refining of some metallic ores releases lead into the environment. Inhalation of contaminated air, consumption of contaminated food and water, and contact with dust that contains lead raises venous blood le...

  5. Method of utilization of alum shales

    Energy Technology Data Exchange (ETDEWEB)

    Dahlerus, C G

    1908-07-04

    A procedure - by means of reducing smelting of bituminous alum shales in a closed furnace process with or without the use of additional fuel and without adding lime or other slag-forming material - to utilize the hydrocarbons and tar oils formed, and likewise the alkali, nitrogen, and sulfur compositions is given. This is accomplished by making these products follow the furnace gases, and later separating them from the gases by cooling for condensation. The patent contains one more claim.

  6. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China

    OpenAIRE

    Yue Wu; Jun-Ming Gu; Yun Huang; Yan-Ying Duan; Rui-Xue Huang; Jian-An Hu

    2016-01-01

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China’s existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between o...

  7. Environmental monitoring of the Robertson Reservoir (1990-2005) : evolution of the mercury levels in the flesh of fish

    International Nuclear Information System (INIS)

    Therrien, J.

    2006-04-01

    This paper provided details of an environmental monitoring analysis of the stomach contents and mercury levels in the flesh of main fish species in the Robertson Reservoir. The report noted that smelt species were dominant in the reservoir and in the adjoining Ivry Lake, while benthos were dominant the brackish waters of Lake Monger. Sticklebacks were found in the stomachs of the examined fish, while the diet of brook trout was comprised mainly of benthos in lakes and reservoirs. Arctic char mainly ate benthos in the reservoir. Landlocked salmon mainly ate fish in the reservoirs and lakes. Smelt was the primary diet of Arctic char until 2003. After 2003, Arctic char fed mainly on sticklebacks. It was observed that average mercury levels of fish of a standardized length increased by a factor of 2.7 to 4.9 after the impoundment of the reservoir. However, average mercury levels stopped increasing for dwarf Arctic char in 2003. Levels of mercury in brook trout have not increased since 1999. A significant decrease in mercury levels of rainbow smelt were observed. Average mercury levels of fish in the brackish waters of Lake Monger were lower than levels observed in most other freshwater lakes in the region. It was concluded that the number of monthly meals recommended by the fish consumption guide produced in 2001 for the Gros Mecatina region are still appropriate for the reservoir

  8. Large-Scale Consumption and Zero-Waste Recycling Method of Red Mud in Steel Making Process

    Directory of Open Access Journals (Sweden)

    Guoshan Ning

    2018-03-01

    Full Text Available To release the environmental pressure from the massive discharge of bauxite residue (red mud, a novel recycling method of red mud in steel making process was investigated through high-temperature experiments and thermodynamic analysis. The results showed that after the reduction roasting of the carbon-bearing red mud pellets at 1100–1200 °C for 12–20 min, the metallic pellets were obtained with the metallization ratio of ≥88%. Then, the separation of slag and iron achieved from the metallic pellets at 1550 °C, after composition adjustment targeting the primary crystal region of the 12CaO·7Al2O3 phase. After iron removal and composition adjustment, the smelting-separation slag had good smelting performance and desulfurization capability, which meets the demand of sulfurization flux in steel making process. The pig iron quality meets the requirements of the high-quality raw material for steel making. In virtue of the huge scale and output of steel industry, the large-scale consumption and zero-waste recycling method of red mud was proposed, which comprised of the carbon-bearing red mud pellets roasting in the rotary hearth furnace and smelting separation in the electric arc furnace after composition adjustment.

  9. Respirator use and its impact on particulate matter exposure in aluminum manufacturing facilities.

    Science.gov (United States)

    Liu, Sa; Noth, Elizabeth; Eisen, Ellen; Cullen, Mark R; Hammond, Katharine

    2018-05-31

    Objectives As part of a large epidemiologic study of particulate health effect, this study aimed to report respirator use among total particulate matter (TPM) samples collected in a major aluminum manufacturing company from 1966‒2013 and evaluate the impact of respirator-use adjustment on exposure estimation. Methods Descriptive analyses were performed to evaluate respirator use across facilities and by facility type and job. Protection factors were applied to TPM measurements for recorded respirator use. Estimated TPM exposure for each job ‒ before and after respirator-use adjustment ‒ were compared to assess the impact of adjustment on exposure estimation. Results Respirator use was noted for 37% of 12 402 full-shift personal TPM samples. Measured TPM concentration ranged from less than detectable to 8220 mg/m3, with arithmetic mean, median and standard deviation being 10.6, 0.87 and 130 mg/m 3 , respectively. Respirators were used more often in smelting facilities (52% of TPM measurements) than in fabricating (17%) or refinery facilities (28%) (Pfacilities were subject to respirator-use adjustment, whereas it was 20% and 70% in fabricating and refinery facilities, respectively. Applying protection factors to TPM measurements significantly reduced estimated job mean TPM exposures and changed exposure categories in these facilities, with larger impact in smelting than fabricating facilities. Conclusions Respirator use varied by time, facility and job. Adjusting respirator use resulted in differential impact in smelting and fabricating facilities, which will need to be incorporated into ongoing epidemiologic studies accordingly.

  10. Thermodynamic analysis of dust sulphation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yongxiang; Jokilaakso, A.

    1997-12-31

    Sulphation reactions of metal oxides with SO{sub 2} and O. or SO{sub 3} play significant roles in sulphation roasting of sulphide and oxide minerals as well as in desulphurisation process of combustion gases. In metallurgical waste-heat boilers for sulphide smelting, the sulphation of the oxidic flue dust in the atmosphere containing sulphur oxides is an unavoidable process, and the sulphation reactions have to be guided in a controlled way in the proper parts of the gas handling equipment. In this report, some thermodynamic analyses were conducted for the oxide sulphation reactions in relation to sulphide smelting processes. The phase stability of Me-S-O systems especially for oxides - sulphates equilibrium was studied under different thermodynamic conditions of gas compositions and temperatures. The sulphate stability was analysed for an example of gas compositions in the copper flash smelter of Outokumpu Harjavalta Metals Oy, in relation to temperature. In the report, most of the information was from literature. Moreover, a number of thermodynamic computations were carried out with the HSC program, and the constructed phase stability diagrams were compared with those from the literature whenever possible. The maximum temperatures for stable sulphates under normal operating conditions of the waste-heat boilers in sulphide smelting processes were obtained. This report will serve as the basis for the kinetic studies of the sulphation reactions and the sulphation reaction modelling in pyrometallurgical processes. (orig.) SULA 2 Programme. 36 refs.

  11. Selenium and Other Trace Element Mobility in Waste Products and Weathered Sediments at Parys Mountain Copper Mine, Anglesey, UK

    Directory of Open Access Journals (Sweden)

    Liam A. Bullock

    2017-11-01

    Full Text Available The Parys Mountain copper mining district (Anglesey, North Wales hosts exposed pyritic bedrock, solid mine waste spoil heaps, and acid drainage (ochre sediment deposits. Both natural and waste deposits show elevated trace element concentrations, including selenium (Se, at abundances of both economic and environmental consideration. Elevated concentrations of semi-metals such as Se in waste smelts highlight the potential for economic reserves in this and similar base metal mining sites. Selenium is sourced from the pyritic bedrock and concentrations are retained in red weathering smelt soils, but lost in bedrock-weathered soils and clays. Selenium correlates with Te, Au, Bi, Cd, Hg, Pb, S, and Sb across bedrock and weathered deposits. Man-made mine waste deposits show enrichment of As, Bi, Cu, Sb, and Te, with Fe oxide-rich smelt materials containing high Pb, up to 1.5 wt %, and Au contents, up to 1.2 ppm. The trace elements As, Co, Cu, and Pb are retained from bedrock to all sediments, including high Cu content in Fe oxide-rich ochre sediments. The high abundance and mobility of trace elements in sediments and waters should be considered as potential pollutants to the area, and also as a source for economic reserves of previously extracted and new strategic commodities.

  12. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    International Nuclear Information System (INIS)

    Smith, K.P.; Blunt, D.L.; Williams, G.P.

    1996-09-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of this assessment, it is concluded that (1) regulations requiring workers to wear respiratory protection during equipment cleaning operations are likely to result in lower worker doses, (2) underground injection and downhole encapsulation of NORM wastes present a negligible risk to the general public, and (3) potential doses to workers and the general public related to smelting NORM-contaminated equipment can be controlled by limiting the contamination level of the initial feed. It is recommended that (1) NORM wastes be further characterized to improve studies of potential radiological doses; (2) states be encouraged to permit subsurface disposal of NORM more readily, provided further assessments support this study; results; (3) further assessment of landspreading NORM wastes be conducted; and (4) the political, economic, sociological, and nonradiological issues related to smelting NORM-contaminated equipment be studied to fully examine the feasibility of this disposal option

  13. Isolation of technogenic magnetic particles

    Energy Technology Data Exchange (ETDEWEB)

    Catinon, Mickaël, E-mail: mickael.catinon@gmail.com [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France); Ayrault, Sophie, E-mail: sophie.ayrault@lsce.ispl.fr [Laboratoire des Sciences du Climat et de l' Environnement, UMR 8212, CEA-CNRS-UVSQ/IPSL, 91198 Gif-sur-Yvette (France); Boudouma, Omar, E-mail: boudouma@ccr.jussieu.fr [Service du MEB, UFR928, Université Pierre et Marie Curie, 75252 Paris VI (France); Bordier, Louise, E-mail: Louise.Bordier@lsce.ipsl.fr [Laboratoire des Sciences du Climat et de l' Environnement, UMR 8212, CEA-CNRS-UVSQ/IPSL, 91198 Gif-sur-Yvette (France); Agnello, Gregory, E-mail: contact@evinrude.fr [Evinrude, Espace St Germain, 38200 Vienne (France); Reynaud, Stéphane, E-mail: stephane.reynaud@ujf-grenoble.fr [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France); Tissut, Michel, E-mail: michel.tissut@ujf-grenoble.fr [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France)

    2014-03-01

    Technogenic magnetic particles (TMPs) emitted by various industrial sources, such as smelting plants, end up after atmospheric transfer on the soil surface. In the present study, we characterised the origin and composition of such particles emitted by a large iron smelting plant and deposited on particular substrates, namely tombstones, which act as a very interesting and appropriate matrix when compared to soil, tree bark, lichens or attic dust. The isolation and subsequent description of TMPs require a critical step of separation between different components of the sample and the magnetic particles; here, we described an efficient protocol that fulfils such a requirement: it resorts to water suspension, sonication, repeated magnetic extraction, sedimentation, sieving and organic matter destruction at 550 °C in some instances. The isolated TMPs displayed a noticeable crystalline shape with variable compositions: a) pure iron oxides, b) iron + Cr, Ni or Zn, and c) a complex structure containing Ca, Si, Mg, and Mn. Using Scanning Electron Microscope Energy Dispersive X-ray (SEM–EDX), we obtained profiles of various and distinct magnetic particles, which allowed us to identify the source of the TMPs. - Highlights: • The developed method offers a low-cost approach of large-scale dry deposition. • Tombstones are excellent supports for sampling these atmospheric deposits. • Smelted elements crystallise after cooling, giving typical technogenic magnetic particles (TMPs). • Coupling microscopic and bulk analyses allows identifying TMP origin. • Magnetic TMPs issued from steel industry were separated by a new technique.

  14. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    Science.gov (United States)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  15. Antimony bioavailability in mine soils

    International Nuclear Information System (INIS)

    Flynn, Helen C.; Meharg, Andy A.; Bowyer, Phillipa K.; Paton, Graeme I.

    2003-01-01

    Antimony has low bioavailability in mining and smelting contaminated soils and bacterial biosensors are not suitable for its detection. - Five British former mining and smelting sites were investigated and found to have levels of total Sb of up to 700 mg kg -1 , indicating high levels of contamination which could be potentially harmful. However, this level of Sb was found to be biologically unavailable over a wide range of pH values, indicating that Sb is relatively unreactive and immobile in the surface layers of the soil, remaining where it is deposited rather than leaching into lower horizons and contaminating ground water. Sb, sparingly soluble in water, was unavailable to the bacterial biosensors tested. The bioluminescence responses were correlated to levels of co-contaminants such as arsenic and copper, rather than to Sb concentrations. This suggests that soil contamination by Sb due to mining and smelting operations is not a severe risk to the environment or human health provided that it is present as immobile species and contaminated sites are not used for purposes which increase the threat of exposure to identified receptors. Co-contaminants such as arsenic and copper are more bioavailable and may therefore be seen as a more significant risk

  16. Metallography and microstructure interpretation of some archaeological tin bronze vessels from Iran

    Energy Technology Data Exchange (ETDEWEB)

    Oudbashi, Omid, E-mail: o.oudbashi@aui.ac.ir [Department of Conservation of Historic Properties, Faculty of Conservation, Art University of Isfahan, Hakim Nezami Street, Sangtarashha Alley, P.O. Box 1744, Isfahan (Iran, Islamic Republic of); Davami, Parviz, E-mail: pdavami@razi-foundation.com [Faculty of Material Science and Engineering, Sharif University of Technology/Razi Applied Science Foundation, No. 27, Fernan St., Shahid Ghasem Asghari Blvd., km 21 of Karadj Makhsous Road, Tehran (Iran, Islamic Republic of)

    2014-11-15

    Archaeological excavations in western Iran have recently revealed a significant Luristan Bronzes collection from Sangtarashan archaeological site. The site and its bronze collection are dated to Iron Age II/III of western Iran (10th–7th century BC) according to archaeological research. Alloy composition, microstructure and manufacturing technique of some sheet metal vessels are determined to reveal metallurgical processes in western Iran in the first millennium BC. Experimental analyses were carried out using Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy and Optical Microscopy/Metallography methods. The results allowed reconstructing the manufacturing process of bronze vessels in Luristan. It proved that the samples have been manufactured with a binary copper–tin alloy with a variable tin content that may relates to the application of an uncontrolled procedure to make bronze alloy (e.g. co-smelting or cementation). The presence of elongated copper sulphide inclusions showed probable use of copper sulphide ores for metal production and smelting. Based on metallographic studies, a cycle of cold working and annealing was used to shape the bronze vessels. - Highlights: • Sangtarashan vessels are made by variable Cu-Sn alloys with some impurities. • Various compositions occurred due to applying uncontrolled smelting methods. • The microstructure represents thermo-mechanical process to shape bronze vessels. • In one case, the annealing didn’t remove the eutectoid remaining from casting. • The characteristics of the bronzes are similar to other Iron Age Luristan Bronzes.

  17. Socio-demographic characteristics of traditional gold smelters in Makassar, south Sulawesi, Indonesia

    Science.gov (United States)

    Habo Abbas, Hasriwiani; Sakakibara, Masayuki; Hakim Arma, Lukmanul; Hardi Yanti, Iva

    2017-06-01

    The traditional gold smelting in Makassar, South Sulawesi, Indonesia, is an informal work with the manufacture of gold jewelry as the core activity. Stages of the gold processing include panning, smelting, and refining with mercury. In the current study, we used a social demography analysis to classify the traditional gold smelter workers in this region. Data (e.g. sex, age, education level, time working, and income) were obtained from a questionnaire survey of 58 smelter workers in the Wajo and Tallo Sub-districts of Makassar. Results showed that 84.5% of the workers were males aged from 21 to 50 years with on the average 15 year of work. The gold smelter were last educated in elementary school (31.0%), junior high school (36.2%), and senior high school (27.6%) levels whereas 5.1% have no education. We found that the monthly income of an un-skilled worker was ∼Rp. 2 million (USD 147.0) whereas that of a skilled worker was between Rp. 2.5 million (USD 183.76) and Rp. 5 million (USD 367.51). An owner could earn over Rp. 5 million (USD 367.51) per month. The result suggested that the traditional gold smelting used rudimentary technique and attracted young people with a low education level. This business continues to exist because the worker earn sufficient income and may higher through mastering gold smelter proficiency.

  18. Were mercury emission factors for Chinese non-ferrous metal smelters overestimated? Evidence from onsite measurements in six smelters

    International Nuclear Information System (INIS)

    Zhang Lei; Wang Shuxiao; Wu Qingru; Meng Yang; Yang Hai; Wang Fengyang; Hao Jiming

    2012-01-01

    Non-ferrous metal smelting takes up a large proportion of the anthropogenic mercury emission inventory in China. Zinc, lead and copper smelting are three leading sources. Onsite measurements of mercury emissions were conducted for six smelters. The mercury emission factors were 0.09–2.98 g Hg/t metal produced. Acid plants with the double-conversion double-absorption process had mercury removal efficiency of over 99%. In the flue gas after acid plants, 45–88% was oxidized mercury which can be easily scavenged in the flue gas scrubber. 70–97% of the mercury was removed from the flue gas to the waste water and 1–17% to the sulfuric acid product. Totally 0.3–13.5% of the mercury in the metal concentrate was emitted to the atmosphere. Therefore, acid plants in non-ferrous metal smelters have significant co-benefit on mercury removal, and the mercury emission factors from Chinese non-ferrous metal smelters were probably overestimated in previous studies. - Highlights: ► Acid plants in smelters provide significant co-benefits for mercury removal (over 99%). ► Most of the mercury in metal concentrates for smelting ended up in waste water. ► Previously published emission factors for Chinese metal smelters were probably overestimated. - Acid plants in smelters have high mercury removal efficiency, and thus mercury emission factors for Chinese non-ferrous metal smelters were probably overestimated.

  19. Recycling abandoned lead battery sites

    International Nuclear Information System (INIS)

    Montgomery, A.H.

    1993-01-01

    In the past, automobile batteries were recycled principally for their lead content. The waste generated at battery wrecking facilities consisted of spent acid, crushed casings (ebonite and plastic), and where secondary smelting was involved, matte, slag, and carbon from the smelting process. These waste products were generally disposed in an on-site in a landfill or stored in piles. If the facility shut down because further commercial operations were not financially viable, the waste piles remained to be addressed at a later date through remedial action or reclamation programs. There are many of these facilities in the US. Nationally, about 28 sites have been discovered by the US Environmental Protection Agency (EPA) under the Superfund program and are under investigation or administrative orders for remedial action. A major remediation effort is now underway at the Gould Superfund Site in Portland, Oregon, which was operated as a secondary smelting facility between 1949 and 1981. This paper describes the nature of the contamination at the Gould site and the work conducted by Canonie Environmental Services Corp. (Canonie) to develop a process which would treat the waste from battery wrecking operations and produce revenue generating recyclable products while removing the source contamination (lead) from the site. The full-scale commercial plant is now operating and is expected to achieve a throughput rate of between 200 and 250 tons per day in the coming weeks

  20. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; R. Michael Bergen; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Alfred H. Stiller; W. Morgan Summers; John W. Zondlo

    2006-05-12

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale.

  1. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

    Science.gov (United States)

    Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

    2017-01-31

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  2. Contaminant Characteristics and Health Risk Assessment of Heavy Metals in Soils from Lead-Zincs Melting Plant in Huize County, Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    LIU Xiao-yan

    2016-05-01

    Full Text Available In order to explore history environmental problems of lead-zinc smelting, Huize County, Yunnan Province, forty-two surface soil samples were collected randomly from 14 sampling sites surrounding lead-zinc smelting plant. Heavy metals(Cr, Cu, Mn, Ni, Pb, Zn, Cd, As and Hg in all samples were determined by inductively coupled plasma-optical emission spectroscopy and atomic fluorescence spectrophotometer. Contamination characteristics of heavy metals in soils were observed on the basis of background values of comprehensive pollution index method. Potential risk was evaluated by using the geoaccumulation index(Igeo, potential ecological risk index(RI and health risk assessment method. The results indicated that the average concentrations of Cr, Cu, Mn, Ni, Pb, Zn, Cd, As and Hg were 92.25, 226.81, 1 567.45, 65.16, 394.66, 1 451.63, 11.16, 43.81, 0.47 mg·kg-1, respectively. Based on the Environmental Quality Standard for Soil, the multiple super scale of Cd concentration was highest, more than 274 times. According to the Igeo, Cd ranged from partial severity to serious degree. The RI indicated that the soils around lead-zinc smelting plant were at the serious ecological hazard level. Health risk assessment showed that Pb and Cd in soils surrounding old site had potential health risk to children.

  3. Distribuição e abundância dos caranguejos Uca Leach (Crustacea, Decapoda, Ocypodidae na Baía de Guaratuba, Paraná, Brasil Distribution and abundance of fiddler crabs Uca Leach (Crustacea Decapoda Ocypodidae in Guaratuba Bay, Parana State, southern Brazil

    Directory of Open Access Journals (Sweden)

    Setuko Masunari

    2006-12-01

    Full Text Available Um estudo sobre distribuição espacial e abundância dos chama-marés Uca Leach, 1814 foi realizado na Baía de Guaratuba, Estado do Paraná. Foram coletados chama-marés de dez biótopos ao longo de um gradiente de salinidade de zero a 32 dentro da Baía de Guaratuba. Foram obtidas sete espécies, entre as quais, Uca mordax (Smith, 1870 que foi registrada somente em biótopos inundados por águas de baixas salinidades (de zero a 16. As demais espécies mostraram tolerância a uma ampla variação de salinidade, mas Uca maracoani (Latreille, 1802-1803 e Uca leptodactyla Rathbun, 1898 predominaram em águas mais salinas, de 14 a 32, enquanto U. burgersi Holthuis, 1967, Uca rapax (Smith, 1870, Uca thayeri Rathbun, 1900 e Uca uruguayensis Nobili, 1901 foram coletadas em mais de três biótopos e mostraram uma tendência ao eurihalismo, suportando salinidades de 4 a 32. Entretanto, outras características do substrato tais como porcentagem relativa de cascalho/areia/silte/argila, teor de matéria orgânica e presença de marismas, também, influenciaram a distribuição espacial destes caranguejos. U. leptodactyla foi registrada com densidade máxima de 240 ind.m-2, o mais alto valor conhecido.A study of the spatial distribution and abundance of fiddler crabs was carried out in Guaratuba Bay, Parana State, southern Brazil. Fiddler crabs were collected from 10 biotopes located along a salinity gradient from zero to 32 inside Guaratuba Bay (between 48°30'W-25°50'S and 48°45'W-25°54'S. Seven species were found, among which, Uca mordax (Smith, 1870 occurred only in biotopes inundated by low salinity water, from zero to 16. Remaining species tolerated wide range of salinity oscillation, but Uca maracoani (Latreille, 1802-1803 and Uca leptodactyla Rathbun, 1898 predominated in saltier waters, from 14 to 32, while U. burgersi Holthuis, 1967, Uca rapax (Smith, 1870, Uca thayeri Rathbun, 1900, and Uca uruguayensis Nobili, 1901 were collected in more

  4. Diversidade de morcegos (Mammalia, Chiroptera do Complexo Aporé-Sucuriú, Mato Grosso do Sul, Brasil Bat Diversity (Mammalia, Chiroptera from Aporé-Sucuriú's complex, Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo O. Bordignon

    2006-12-01

    Full Text Available Realizou-se um inventário da fauna de morcegos entre abril e novembro de 2004 no norte de Mato Grosso do Sul, Brasil (Projeto Jauru/MMA. Oito pontos de coleta foram amostrados com redes-neblina em um ambiente de cerrado, sendo capturados 146 indivíduos de 28 espécies, distribuídos em seis famílias. O total de espécies neste estudo, representa apenas 30% da fauna de morcegos do cerrado. A família mais capturada foi a Phyllostomidae, representada por Glossophaga soricina (Pallas, 1766 e Artibeus lituratus (Olfers, 1818. Algumas espécies raras foram capturadas: Lophostoma brasiliense (Peters, 1866, Lonchophylla mordax Thomas, 1903 e Lionycteris spurrelli Thomas, 1913. O local de maior abundância (0,032 indivíduos/m²/h mostrou um índice de Simpson de D = 3.86 e o de menor abundância (0,003 indivíduos/m²/h um índice de Simpson de D = 3.03. A preservação dos mananciais de água e a cobertura florestal nestes pontos são discutidas.From April to November 2004 was made a bat fauna inventory in Northern of Mato Grosso do Sul, Brazil (Jauru's Project/MMA. Eight points was sampled with mist-nets in a cerrado's ecosystem and was caught 146 individuals de 28 species, distributed into six bat families. The total of species in this study just represents 30% of cerrado's bat fauna. The more caught family was Phyllostomidae represented by Glossophaga soricina (Pallas, 1766 and Artibeus lituratus (Olfers, 1818. Some rare species were caught: Lophostoma brasiliense (Peters, 1866, Lonchophylla mordax Thomas, 1903 and Lionycteris spurrelli Thomas, 1913. The more abundant point sampled (0.032 bat/m²/h shown a Simpson index of D = 3.86 and the low abundant point sampled (0.003 bat/m²/h was D = 3.03. The preservation of water springs and forest cover in study sites are discussed.

  5. [The enzymes of carbohydrates metabolism from Cysttidicola farionis (Cystidicolidae)].

    Science.gov (United States)

    Zółtowska, K; Lopieńska, E; Rokicki, J; Dmitryjuk, M

    2001-01-01

    The content of glycogen, glucose and trehalose was measured in larvae and adults of Cystidicola farionis, the parasite isolated from the swim bladder of Osmerus eperlanus from Vistula Lagoon. Activity of glycogen phosphorylase, alpha-amylase, glucoamylase, maltase, trehalase, and trehalose phosphorylase were measured. The highest activity was recorded for alpha-amylase 10.07 +/- 0.97 mu/mg and 7.47 +/- 0.24 mu/mg, next maltase 1.34 +/- 0.63 micromol/mg and 2.06 +/- 1.65 micronol/mg respectively for larvae and adults. The activity of glucoamylase was nearly the same for adults and larvae (about 0.20 micromol/mg). The trehalase activity was higher at adults (0.49 +/- 0.42 micromol/mg) than at larvae (0.18 +/- 0.12 micromol/mg). The activity of glycogen phosphorylase was much higher at larvae (3.58 +/- 1.49 micromol/mg) than at adults parasite (0.10 +/- 0.02 micromol/mg). The trehalose phosphorylase was present in both stages of parasite, but its activity was low. The content of glycogen and glucose was two-times higher in the adults' body than in larvae.

  6. The type specimens of sawflies (Hymenoptera: Symphyta) of the Museo Nacional de Ciencias Naturales, Madrid.

    Science.gov (United States)

    Taeger, Andreas; París, Mercedes; Nieves-Aldrey, Jose Luis

    2014-04-16

    The type specimens of sawflies (Hymenoptera: Symphyta) housed in the Museo Nacional de Ciencias Naturales, Madrid, were examined. Lectotypes are designated and illustrated for the following 32 nominal taxa (preserved in the MNCN collection if not stated otherwise): Tenthredo acutiscutis Konow, 1908; Tenthredo aericeps Konow, 1907; Allantus albipectus Konow, 1907; Athalia bolivari Dusmet, 1896; Tristactus punctatus var. candidatus Konow, 1899; Tenthredo capistrata Konow, 1907; Megalodontes capitalatus Konow 1904 (coll. SDEI); Tenthredo casta Konow, 1908; Clydostomus cestatus Konow, 1908; Miocephala chalybea Konow, 1907 (coll. SDEI); Peus cupreiceps Konow, 1907; Metallopeus cupreolus Malaise, 1945 (coll. NHRS); Allantus dusmeti Konow, 1894 (coll. SDEI); Megalodontes dusmeti Enslin, 1914 (coll. ZSM); Megalodontes escalerai Konow, 1899; Tenthredo flavitarsis Konow, 1908; Sciopteryx galerita Konow, 1907; Tenthredo habenata Konow, 1907; Allantus inguinalis Konow, 1908; Clydostomus merceti Konow, 1908; Megalodontes merceti Konow 1904 (coll. SDEI); Tenthredo mordax Konow, 1908; Megalodontes mundus Konow, 1904; Tenthredo nimbata Konow, 1906; Tenthredo oculissima Konow, 1907; Peus pannulosus Konow, 1907; Tenthredo podagrica Konow, 1907; Arge segmentaria var. rufiventris Konow, 1899; Tenthredo rugiceps Konow, 1908; Tenthredo segrega Konow, 1908; Peus splendidus Konow 1907; Tenthredo suta Konow, 1906. Peus cupreiceps Konow, 1907, is considered to be a valid species. New synonymy is proposed for Tenthredo (Metallopeus) cupreiceps (Konow, 1907), comb. nov., spec. rev. (=Metallopeus cupreolus Malaise, 1945, syn. nov.; =Metallopeus inermis Malaise, 1945, syn. nov.). 

  7. Development of free neuromasts in Engraulis ringens and Strangomera bentincki (Teleostei, Clupeiformes early larvae

    Directory of Open Access Journals (Sweden)

    Alejandra Llanos-Rivera

    2014-03-01

    Full Text Available Neuromast morphology and distribution are characterized during early ontogeny of anchoveta (Engraulis ringens and common sardine (Strangomera bentincki. Although both species share morphological features, they show several differences during their early ontogeny, such as size at hatching and yolk absorption. Larvae were obtained from incubation of planktonic eggs (at 12°C, collected during the spawning season 2001 (August-September at Coliumo Bay. The neuromasts were observed from hatching to 25 days, and the pattern of neuromast appearance, in newly hatched larva, until yolk absorption, was determined using Janus Green staining and scanning electronic microscope. Results showed a similar pattern of neuromast development in both species. At hatching, two pairs of neuromasts were observed in the cephalic area and 8-9 in the rest of the body, which increased to 19 pairs and to 30-39 pairs at a larval size of 11 mm, respectively. On the average, 12 hair cells per neuromast were counted, with little variation among neuromasts. The polarity of these hair cells was closest to multiple polarity. Neuromast positioning for both species, anchoveta and common sardine larvae, are similar to those of Engraulis mordax and Clupea harengus, respectively. The similar development pattern of these species seems to be related to similar functional constraints and close taxonomic affinity.

  8. Hyperactive antifreeze proteins from longhorn beetles: some structural insights.

    Science.gov (United States)

    Kristiansen, Erlend; Wilkens, Casper; Vincents, Bjarne; Friis, Dennis; Lorentzen, Anders Blomkild; Jenssen, Håvard; Løbner-Olesen, Anders; Ramløv, Hans

    2012-11-01

    This study reports on structural characteristics of hyperactive antifreeze proteins (AFPs) from two species of longhorn beetles. In Rhagium mordax, eight unique mRNAs coding for five different mature AFPs were identified from cold-hardy individuals. These AFPs are apparently homologues to a previously characterized AFP from the closely related species Rhagium inquisitor, and consist of six identifiable repeats of a putative ice binding motif TxTxTxT spaced irregularly apart by segments varying in length from 13 to 20 residues. Circular dichroism spectra show that the AFPs from both species have a high content of β-sheet and low levels of α-helix and random coil. Theoretical predictions of residue-specific secondary structure locate these β-sheets within the putative ice-binding motifs and the central parts of the segments separating them, consistent with an overall β-helical structure with the ice-binding motifs stacked in a β-sheet on one side of the coil. Molecular dynamics models based on these findings show that these AFPs would be energetically stable in a β-helical conformation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Macro-Scale Patterns in Upwelling/Downwelling Activity at North American West Coast.

    Directory of Open Access Journals (Sweden)

    Romeo Saldívar-Lucio

    Full Text Available The seasonal and interannual variability of vertical transport (upwelling/downwelling has been relatively well studied, mainly for the California Current System, including low-frequency changes and latitudinal heterogeneity. The aim of this work was to identify potentially predictable patterns in upwelling/downwelling activity along the North American west coast and discuss their plausible mechanisms. To this purpose we applied the min/max Autocorrelation Factor technique and time series analysis. We found that spatial co-variation of seawater vertical movements present three dominant low-frequency signals in the range of 33, 19 and 11 years, resembling periodicities of: atmospheric circulation, nodal moon tides and solar activity. Those periodicities might be related to the variability of vertical transport through their influence on dominant wind patterns, the position/intensity of pressure centers and the strength of atmospheric circulation cells (wind stress. The low-frequency signals identified in upwelling/downwelling are coherent with temporal patterns previously reported at the study region: sea surface temperature along the Pacific coast of North America, catch fluctuations of anchovy Engraulis mordax and sardine Sardinops sagax, the Pacific Decadal Oscillation, changes in abundance and distribution of salmon populations, and variations in the position and intensity of the Aleutian low. Since the vertical transport is an oceanographic process with strong biological relevance, the recognition of their spatio-temporal patterns might allow for some reasonable forecasting capacity, potentially useful for marine resources management of the region.

  10. Temporal and sex-specific variability in Rhinoceros Auklet diet in the central California Current system

    Science.gov (United States)

    Carle, Ryan D.; Beck, Jessie N.; Calleri, David M.; Hester, Michelle M.

    2015-06-01

    We used stable isotopes (δ15N and δ13C) and compared prey provided to chicks by each sex to evaluate seasonal and sex-specific diets in Rhinoceros Auklets (Cerorhinca monocerata) in the central California Current system during 2012-2013. Mixing models indicated northern anchovy (Engraulis mordax) were important prey for adults during fall/winter and juvenile rockfishes (Sebastes spp.) were important prey during incubation both years. Adult trophic level increased between incubation and chick-rearing periods in both years. During 2012, δ15N and δ13C of chick-rearing males and females differed significantly; mixing models indicated that females ate more Pacific saury (Cololabis saira) and less market squid (Doryteuthis opalescens) than males. Likewise, females delivered significantly more Pacific saury and less market squid to chicks than males during 2012. Chick growth (g d- 1) and chick survival to fledging were significantly lower during 2012 than 2013, likely because chicks were fed lesser quality prey or fed less frequently in 2012. Lesser body mass of females during incubation in 2012 indicated sex-specific diet differences may have been related to female energetic constraints. The observed variability in Rhinoceros Auklet diet underscores the importance of managing multiple prey populations in this system so that generalist predators have sufficient resources through changing conditions.

  11. NUEVOS REGISTROS DE ESPECIES DE MURCIÉLAGOS PARA EL DEPARTAMENTO DE SUCRE Y ALGUNOS DATOS SOBRE SU ECOLOGÍA EN ESTA REGIÓN COLOMBIANA

    Directory of Open Access Journals (Sweden)

    SAMPEDRO MARÍN ALCIDES C.

    2007-12-01

    Full Text Available Se realizaron 33 muestreos de murciélagos en diferentes localidades de la zonaurbana y rural del departamento de Sucre, entre los años 2004 y 2005. Se utilizaronredes de niebla, tanto para campo abierto como para refugios, entre las 1800 hs ylas 0600 hs del día siguiente. Se registraron 22 especies, de las cuales seis resultannuevos registros para Sucre: Artibeus obscurus, Sturnira erythromus, Phyllostomuselongatus, Lonchophylla mordax, Peropterix macrotis y Rhogeesa tumida. La familiamás numerosa fue Phyllostomidae. La mayor abundancia relativa (frecuencia decaptura en la zona urbana la presentaron Molossus molossus (78.3%, Artibeusobscurus (65.2% y Loncophylla thomasi (56.5%. En la zona rural la más abundanteresultó Desmodus rotundus (100% de los muestreos, seguida por Noctilio albiventrisy Sacopterix bilineata (30%. Ambas comunidades de murciélagos (urbana y ruralson similares en un 48%, ya que sólo siete de las especies resultaron comunes a lasdos. Los refugios más frecuentados en la zona rural son los árboles, sobre todo elCaracolí (Anacardium excelsum y la mayor riqueza de especies se encontró en losrefugios más grandes. La actividad nocturna es significativamente diferente entre lasespecies (X2 = 323, p mecanismos de reducción de la competencia por el alimento, sobre todo en lasespecies vegetariana

  12. Epigeic spiders of the pastures of northern Wielkopolska

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    Woźny, Marek

    2000-10-01

    Full Text Available The fauna of epigeic spiders (Araneae occurring on three different types of pastures in northern Wielkopolska was analysed. Studies were conducted from May 1992 to October 1993. The 18,995 specimens collected were classified as belonging to 137 species and 17 families. The family Linyphiidae proved the richest in species while Lycosidae was the most abundantly in terms of number of specimens. Zoocenological analysis of spider communities showed their differentiation testifying to differences in the sites studied. The dominants were: 1 Osowo Stare (Site 1: Pardosa palustris, 2 Sycyn Dolny (Site 2: Xerolycosa miniata, P. palustris, Xysticus kochi, 3 Braczewo (Site 3: Erigone dentipalpis, P. palustris. Seasonal changes of dominance of the species at each site were established. A comparison of changes of the species’ dominances in the years 1992 and 1993 disclosed similar values of the individual dominance coefficient at the sites in Osowo Stare and Braczewo. This result indicates the occurrence of the process of stabilization of these biocenoses and a tendency to equilibrium in the environment. The least stable proved to be the site at Sycyn Dolny. Analysis of the seasonal dynamics of epigeic spider communities was also made by determining the mean number of species at each site in the two years of study. The highest number of species was noted in spring. It is interesting to note the appearance of species which are rare or very rare in Poland such as: Lepthyphantes insignis, Ostearius melanopygius, Enoplognatha mordax and Enoplognatha oelandica.

  13. Low CO{sub 2} emission technologies for iron and steelmaking as well as titania slag production

    Energy Technology Data Exchange (ETDEWEB)

    Orth, A.; Anastasijevic, N.; Eichberger, H. [Outokumpu Technol GmbH, Oberursel (Germany)

    2007-08-15

    Outokumpu Technology has developed direct reduction technologies that allow in combination with smelting reduction processes or electric arc furnaces a substantial lowering of CO{sub 2} emissions. In this paper three examples are given: The Circofer process, already demonstrated in pilot plant scale, uses coal as reductant in a two stage CFB (circulating fluidized bed)/FB (fluidized bed) reactor configuration to obtain a highly metallized product suitable for charging into smelting processes. One possible application of Circofer is, in a single stage configuration, as prereduction unit in combination with HIsmelt a smelting reduction technology to produce hot metal using iron ore and coal fines. Using Circofer as prereduction step, the capacity of a given HIsmelt installation can be increased by the factor three to four compared to cold feed and CO, emission can be lowered to values about 20% below the standard of a modern blast furnace, as this combination of technologies requires no agglomeration plant or coke ovens. A second application of Circofer is the combination with an electric arc furnace (EAF) to produce steel directly from direct reduced iron (DRI). Charging hot DRI into an EAF decreases drastically electric power consumption and thus further lowers CO, emission. Applying Circosmelt, the combination of a single stage Circofer system with an electric reduction furnace for ilmenite processing, only half of the electric power consumption required today for titania slag production using cold, unreduced feed material is required. A common additional advantage of all Circofer based routes is that a 99% pure CO{sub 2} stream is removed for process reasons from the process gas and can be used for enhanced crude oil production or sequestration methods.

  14. On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa

    Science.gov (United States)

    Lupo, Karen D.; Schmitt, Dave N.; Kiahtipes, Christopher A.; Ndanga, Jean-Paul; Young, D. Craig; Simiti, Bernard

    2015-01-01

    An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories. PMID:26161540

  15. Mining-caused changes to habitat structure affect amphibian and reptile population ecology more than metal pollution.

    Science.gov (United States)

    Sasaki, Kiyoshi; Lesbarrères, David; Watson, Glen; Litzgus, Jacqueline

    2015-12-01

    Emissions from smelting not only contaminate water and soil with metals, but also induce extensive forest dieback and changes in resource availability and microclimate. The relative effects of such co-occurring stressors are often unknown, but this information is imperative in developing targeted restoration strategies. We assessed the role and relative effects of structural alterations of terrestrial habitat and metal pollution caused by century-long smelting operations on amphibian and reptile communities by collecting environmental and time- and area-standardized multivariate abundance data along three spatially replicated impact gradients. Overall, species richness, diversity, and abundance declined progressively with increasing levels of metals (As, Cu, and Ni) and soil temperature (T(s)) and decreasing canopy cover, amount of coarse woody debris (CWD), and relative humidity (RH). The composite habitat variable (which included canopy cover, CWD, T(s), and RH) was more strongly associated with most response metrics than the composite metal variable (As, Cu, and Ni), and canopy cover alone explained 19-74% of the variance. Moreover, species that use terrestrial habitat for specific behaviors (e.g., hibernation, dispersal), especially forest-dependent species, were more severely affected than largely aquatic species. These results suggest that structural alterations of terrestrial habitat and concomitant changes in the resource availability and microclimate have stronger effects than metal pollution per se. Furthermore, much of the variation in response metrics was explained by the joint action of several environmental variables, implying synergistic effects (e.g., exacerbation of metal toxicity by elevated temperatures in sites with reduced canopy cover). We thus argue that the restoration of terrestrial habitat conditions is a key to successful recovery of herpetofauna communities in smelting-altered landscapes.

  16. Processing capabilties for the elimination of contaminated metal scrapyards at DOE/ORO-managed sites

    International Nuclear Information System (INIS)

    Mack, J.E.; Williams, L.C.

    1982-01-01

    Capabilities exist for reducing all the contaminated nickel, aluminum, and copper scrap to ingot form by smelting. Processing these metals at existing facilities could be completed in about 5 or 6 years. However, these metals represent only about 20% of the total metal inventories currently on hand at the DOE/ORO-managed sites. No provisions have been made for the ferrous scrap. Most of the ferrous scrap is unclassified and does not require secured storage. Also, the potential resale value of the ferrous scrap at about $100 per ton is very low in comparison. Consequently, this scrap has been allowed to accumulate. With several modifications and equipment additions, the induction melter at PGDP could begin processing ferrous scrap after its commitment to nickel and aluminum. The PGDP smelter is a retrofit installation, and annual throughput capabilities are limited. Processing of the existing ferrous scrap inventories would not be completed until the FY 1995-2000 time frame. An alternative proposal has been the installation of induction melters at the other two enrichment facilities. Conceptual design of a generic metal smelting facility is under way. The design study includes capital and operating costs for scrap preparation through ingot storage at an annual throughput of 10,000 tons per year. Facility design includes an induction melter with the capability of melting both ferrous and nonferrous metals. After three years of operation with scrapyard feed, the smelter would have excess capacity to support on-site decontamination and decomissioning projects or upgrading programs. The metal smelting facility has been proposed for FY 1984 line item funding with start-up operations in FY 1986

  17. Alternatives evaluation and decommissioning study on shielded transfer tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    DeVore, J.R.; Hinton, R.R.

    1994-08-01

    The shielded transfer tanks (STTs) are five obsolete cylindrical shipping casks which were used to transport high specific activity radioactive solutions by rail during the 1960s and early 1970s. The STTs are currently stored at the Oak Ridge National Laboratory under a shed roof. This report is an evaluation to determine the preferred alternative for the final disposition of the five STTs. The decommissioning alternatives assessed include: (1) the no action alternative to leave the STTs in their present location with continued surveillance and maintenance; (2) solidification of contents within the tanks and holding the STTs in long term retrievable storage; (3) sale of one or more of the used STTs to private industry for use at their treatment facility with the remaining STTs processed as in Alternative 4; and (4) removal of tank contents for de-watering/retrievable storage, limited decontamination to meet acceptance criteria, smelting the STTs to recycle the metal through the DOE contaminated scrap metal program, and returning the shielding lead to the ORNL lead recovery program because the smelting contractor cannot reprocess the lead. To completely evaluate the alternatives for the disposition of the STTs, the contents of the tanks must be characterized. Shielding and handling requirements, risk considerations, and waste acceptance criteria all require that the radioactive inventory and free liquids residual in the STTs be known. Because characterization of the STT contents in the field was not input into a computer model to predict the probable inventory and amount of free liquid. The four alternatives considered were subjected to a numerical scoring procedure. Alternative 4, smelting the STTs to recycle the metal after removal/de-watering of the tank contents, had the highest score and is, therefore, recommended as the preferred alternative. However, if a buyer for one or more STT could be found, it is recommended that Alternative 3 be reconsidered

  18. Response of magnetic properties to heavy metal pollution in dust from three industrial cities in China

    International Nuclear Information System (INIS)

    Zhu, Zongmin; Li, Zhonggen; Bi, Xiangyang; Han, Zhixuan; Yu, Genhua

    2013-01-01

    Highlights: ► Elevated magnetic particles and heavy metals coexist in dust. ► Morphology and mineralogy of magnetic particles were studied by SEM-EDX and XRD. ► Magnetic minerals in the dust consist of magnetite, hematite, and metallic iron. ► Impact of metallic iron particles and multi-sources of metal pollutants was notable. -- Abstract: Magnetic method is a reliable and powerful technique for identification of the relative contribution of industrial pollutants. However, it has not been fully applied in urban area impacted by non-ferrous metal (NFM) smelting/processing activities. The aim of this study is to explore the applicability of magnetic methods for detecting heavy metal contamination in dust from three NFM smelting/processing industrial cities (Ezhou, Zhuzhou, and Hezhang) in China. The enhancements of magnetic susceptibility (MS) and saturation isothermal remanent magnetization (SIRM) together with heavy metals were significant in the studied areas in comparison with the background values. Scanning electron microscope (SEM) analysis revealed that magnetic particles in dust from Ezhou were dominated by spherules, while those from Zhuzhou and Hezhang were mainly consisted of irregular-shaped particles. κ–T curves and X-ray diffraction (XRD) analyses indicated that the magnetic particles from Ezhou were dominated by magnetite and metallic iron, whereas those from Zhuzhou and Hezhang were consisted of magnetite and hematite. Our study indicates that magnetic properties of the dust are sensitive to the NFM smelting/processing related heavy metal pollutants. However, the relationship between magnetic parameters and heavy metals was influenced by the presence of metallic iron particles and multi-sources of metal pollutants

  19. Materials for the pulp and paper industry. Section 1: Development of materials for black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.R.; Hubbard, C.R.; Payzant, E.A. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Black liquor recovery boilers are essential components of kraft pulp and paper mills because they are a critical element of the system used to recover the pulping chemicals required in the kraft pulping process. In addition, the steam produced in these boilers is used to generate a significant portion of the electrical power used in the mill. Recovery boilers require the largest capital investment of any individual component of a paper mill, and these boilers are a major source of material problems in a mill. The walls and floors of these boilers are constructed of tube panels that circulate high pressure water. Molten salts (smelt) accumulate on the floor of recovery boilers, and leakage of water into the boiler can result in a violent explosion when the leaked water instantly vaporizes upon contacting the molten smelt. Because corrosion of the conventionally-used carbon steel tubing was found to be excessive in the lower section of recovery boilers, use of stainless steel/carbon steel co-extruded tubing was adopted for boiler walls to lessen corrosion and reduce the likelihood of smelt/water explosions. Eventually, this co-extruded or composite (as it is known in the industry) tubing was selected for use as a portion or all of the floor of recovery boilers, particularly those operating at pressures > 6.2 MPa (900 psi), because of the corrosion problems encountered in carbon steel floor tubes. Since neither the cause of the cracking nor an effective solution has been identified, this program was established to develop a thorough understanding of the degradation that occurs in the composite tubing used for walls and floors. This is being accomplished through a program that includes collection and review of technical reports, examination of unexposed and cracked tubes from boiler floors, computer modeling to predict residual stresses under operating conditions, and operation of laboratory tests to study corrosion, stress corrosion cracking, and thermal fatigue.

  20. Çinkonun (Zn+2 Gümüş Balığı (Atherina boyeri, Risso, 1810 Üzerine Akut Toksisitesi

    Directory of Open Access Journals (Sweden)

    Cafer BULUT

    2014-03-01

    Full Text Available In this study it was aimed to determine acute toxicity of zinc on sand smelt (Atherina boyeri. In the experiments were used sand smelt which have average length of 4.41±0.068 cm and weights 0.60±0.027 g. The test fish were exposed to following concentrations of zinc (7.78, 12.96, 21.6, 36, 60 and 100 mg/L for 24 hours. In preparation of test solutions zinc sulphate and artesian water which has temperature 19° C, total hardness 350 mg/L CaCO3 and 5.72 mg/L DO. Test fish were placed in plastic containers to replications experimental groups as hourly and daily morphological observations were made and recorded time of death in acute toxicity test. In zinc-acute toxicity test were used static bioassay methods for 24 hour intervals. Data obtained from the zinc acute toxicity tests were evaluated using the Probit Analysis to LC50 and LT50. LC50 zinc concentrations values were ranged between 1.768 mg/L were observed. The longer the duration of zinc showed a decrease in the value of LC50. LC50 value of the application factor is applied (1.768x0.1 to sand smelt zinc maximum acceptable concentration (safe concentration, 0.1768 mg/L Zn+2, respectively. Lethal concentration, depending on the time interval is 1 hour and 5 minutes to 6 hours 27 minutes LT50 values ranged and decreases the concentrations of zinc have been found. During the experiment, the surface concentrations of fish depending on the movements of assembly and also the opposite effect and side swims away from a fast-moving, uncontrolled swimming, to escape out of the water movement, perpendicular to the water, swimming, breathing movements are observed

  1. Relation between Wet-Bulb Globe Temperature and Thermal Work Limit Indices with Body Core Temperature

    Directory of Open Access Journals (Sweden)

    Mahdi Jalali

    2018-06-01

    Full Text Available Occupational exposure to heat stress in casting and smelting industries can cause adverse health effects on employees who working in such industries. The present study was set to assess the correlation and agreement of heat stress indices, including wet bulb globe temperature (WBGT, and thermal work limit (TWL, and the deep body temperature indices in workers of several casting and smelting industries located in the vicinity of Tehran, Iran. In This cross-sectional study 40 workers randomly selected and were examined. WBGT and TWL were the indices used for assessing heat stress, and the tympanic temperature and the oral temperature were measured as the heat strain indices. The correlation and agreement of indices were measured using SPSS vs.16. The results of the assessment of WBGT, TWL, the tympanic temperature, and oral temperature showed that 80, 17.5, 40, and 32.5 percent of workers exposed to heat stress higher than permissible limits proposed by standard bodies. Moreover, the present study showed that the significant correlation coefficient between heat stress and heat strain indices was in the range of 0.844- 0.869. Further, there was observed a good agreement between TWL and heat strain indices. The agreement between TWL and the oral temperature was 0.63 (P-value≤ 0.001 and between TWL and tympanic temperature was 0.612 (P-value≤ 0.001. However, the agreement between WBGT and heat strain indices was not satisfactory. These values were 0.154 (P-value ≥ 0.068 and 0.215 (P-value≥ 0.028 for the oral temperature and the tympanic temperature, respectively. The TWL index had a better agreement than WBGT with heat strain indices so TWL index is the better choice for assessing the heat stress in casting and metal smelting industries.

  2. Genetic structure and effective population size through time: a tale on two coastal marine species with contrasting life-history patterns

    Directory of Open Access Journals (Sweden)

    Sara Martins Francisco

    2015-12-01

    Full Text Available Species with dispersal mediated by planktonic larvae are expected to be more likely to show temporal genetic variation, due to differences in larval mortality and dispersal ability. The shanny Lipophrys pholis is a typical benthic rocky intertidal fish and its dispersion is limited to its long larval stage. In contrast, the sand-smelt Atherina presbyter has a very short planktonic life, small size and weak swimming capabilities, which translates into reduced dispersion potential. A total of 226 specimens of L. pholis (collected in 2003, 2013 and 2014 and 281 of A. presbyter (collected in 2005, 2012, 2013 and 2014 were screened for genetic variation using the mitochondrial control region. Only 12 (out of 171 and 25 (out of 155 haplotypes found were shared between sampling periods for the shanny and the sand smelt, respectively. For both species, haplotype networks showed a deep genealogy with multiple levels of diversification and no temporal structure. Interestingly, some of the previously inferred missing haplotypes were sampled in more recent years. The genetic diversity indices showed little variation among sampling periods and were generally high. For L. pholis significant genetic differentiation was detected between 2013 and 2014, while no significant differences were detected between sampling periods in A. presbyter. The shanny showed lower effective population size per generation when compared to the sand-smelt (which yielded lack of evidence for genetic drift for the first and second period of the study. These results highlight the fact that temporal changes in the gene pool composition need to be considered when evaluating population structure, especially for species with long pelagic larval dispersion, more vulnerable to fluctuations in the recruitment.

  3. On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa.

    Science.gov (United States)

    Lupo, Karen D; Schmitt, Dave N; Kiahtipes, Christopher A; Ndanga, Jean-Paul; Young, D Craig; Simiti, Bernard

    2015-01-01

    An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories.

  4. SITUATIONAL CONTROL OF HOT BLAST STOVES GROUP BASED ON DECISION TREE

    Directory of Open Access Journals (Sweden)

    E. I. Kobysh

    2016-09-01

    Full Text Available In this paper was developed the control system of group of hot blast stoves, which operates on the basis of the packing heating control subsystem and subsystem of forecasting of modes duration in the hot blast stoves APCS of iron smelting in a blast furnace. With the use of multi-criteria optimization methods, implemented the adjustment of control system conduct, which takes into account the current production situation that has arisen in the course of the heating packing of each hot blast stove group. Developed a situation recognition algorithm and the choice of scenarios of control based on a decision tree.

  5. Social impacts of Brazil's Tucurui Dam

    International Nuclear Information System (INIS)

    Fearnside, P.M.

    1999-01-01

    The Tucurui Dam, which blocked the Tocantins River in 1984 in Brazil's eastern Amazonian state of Para, is a continuing source of controversy. Most benefits of the power go to aluminum smelting companies, where only a tiny amount of employment is generated. Often presented by authorities as a model for hydroelectric development because of the substantial power that it produces, the project's social and environmental impacts are also substantial. Examination of Tucurui reveals a systematic overestimation of benefits and underestimation of impacts as presented by authorities. Tucurui offers many as-yet unlearned lessons for hydroelectric development in Amazonia

  6. Impact assessment of mine drainage water and municipal wastewater on the surface water in the vicinity of Bor

    OpenAIRE

    Gardić Vojka R.; Petrović Jelena V.; Đurđevac-Ignjatović Lidija V.; Kolaković Srđan R.; Vujović Svetlana R.

    2015-01-01

    Mining and copper production in Bor, in the past hundred years, had a huge impact on the environment of town, but also in a wide region. In the area of Bor, in the zone of Mining and Smelting Company (RTB) activity, over 29,000 ha of land under forests and fields is degraded. The area of degraded agricultural land in the Bor municipality is over 60% of total agricultural land. Wastewater, generated in the sites of RTB Bor, pollute the Bor River and Krivelj ...

  7. The iron bars from the ‘Gresham Ship’: employing multivariate statistics to further slag inclusion analysis of ferrous objects

    DEFF Research Database (Denmark)

    Birch, Thomas; Martinón-Torres, Marcos

    2015-01-01

    An assemblage of post-medieval iron bars was found with the Princes Channel wreck, salvaged from the Thames Estuary in 2003. They were recorded and studied, with a focus on metallography and slag inclusion analysis. The investigation provided an opportunity to explore the use of multivariate...... statistical techniques to analyse slag inclusion data. Cluster analysis supplemented by principal components analysis revealed two groups of iron, probably originating from different smelting systems, which were compared to those observed macroscopically and through metallography. The analyses reveal...

  8. Minerals industry survey 1987

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This is the eleventh Minerals Industry Survey produced by the Australian Mining Industry Council. It represents an invaluable time series on the minerals industry's financial performance, as well as an up to date description of the industry for the latest financial year. The survey has been conceived as a supplement to and expansion of the various Australian Bureau of Statistics and Bureau of Mineral Resources, Geology and Geophysics publications which describe the exploration, mining and smelting and refining industries in Australia. The tables in this survey have been prepared by Coopers and Lybrand, Chartered Accountants, based on information supplied to them in confidence by the respondent companies.

  9. Distribución de los contenidos de Fe y Pb en escombreras, suelos y sedimentos del distrito minero de Linares (Jaén)

    OpenAIRE

    El Mabrouki, K.; Hidalgo García, J. M.; Hidalgo Estévez, Mari Carmen; Benavente Herrera, José

    2002-01-01

    Soils and sediments from historical metallic sulphides mining and smelting areas in Linares (jaén) have been sampled for both the determination of the total amount of heavy metals and the analysis by a 5-step sequential extraction procedure. Fe and Pb have been determined on each extraction solution, defined as: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and sulphides, and residual. High concentrations of the total metals were found in all the 12 studied...

  10. Biological desulfurisation

    Energy Technology Data Exchange (ETDEWEB)

    Arena, B.J. [UOP LLC (United States); Benschop, A.; Janssen, A. [Paques Natural Solutions (Netherlands); Kijlstra, S. [Shell Global Solutions (Netherlands)

    2001-03-01

    This article focuses on the biological THIOPAQ process for removing hydrogen sulphide from refinery gases and recovering elemental sulphur. Details are given of the process which absorbs hydrogen sulphide-containing gas in alkaline solution prior to oxidation of the dissolved sulphur to elemental sulphur in a THIOPAQ aerobic biological reactor, with regeneration of the caustic solution. Sulphur handling options including sulphur wash, the drying of the sulphur cake, and sulphur smelting by pressure liquefaction are described. Agricultural applications of the biologically recovered sulphur, and application of the THIOPAQ process to sulphur recovery are discussed.

  11. Using ferrosilicon production slags for reduction of open-hearth steel

    International Nuclear Information System (INIS)

    Grabeklis, A.A.; Vlasov, N.N.; Fadeev, I.G.; Zajchenko, M.V.; Aksenovich, V.I.

    1976-01-01

    Slags from the production of electric furnace ferrosilicon contain a considerable amount of silicon in recovered form (regulus and SiC) and can be used instead of standard ferroalloys (FS18, FS25 and FS45) for deoxidation with silicon in the furnace during the smelting of a number of carbon and alloyed steels. Test open-hearth heats show that highly dispersed SiC in the composition of this slag ensures active diffusion deoxidation and rapid suppression of bath boiling. The test metal can be compared with the conventional one in all the quality aspects, the recovery of phosphorus during deoxidation and tapping slightly increases

  12. Using ferrosilicon production slags for reduction of open-hearth steel

    Energy Technology Data Exchange (ETDEWEB)

    Grabeklis, A A; Vlasov, N N; Fadeev, I G; Zaichenko, M V; Aksenovich, V I [Ural' skij Nauchno-Issledovatel' skij Inst. Chernykh Metallov, Sverdlovsk (USSR)

    1976-05-01

    Slags from the production of electric furnace ferrosilicon contain a considerable amount of silicon in recovered form (regulus and SiC) and can be used instead of standard ferroalloys (FS18, FS25 and FS45) for deoxidation with silicon in the furnace during the smelting of a number of carbon and alloyed steels. Test open-hearth heats show that highly dispersed SiC in the composition of this slag ensures active diffusion deoxidation and rapid suppression of bath boiling. The test metal can be compared with the conventional one in all the quality aspects, the recovery of phosphorus during deoxidation and tapping slightly increases.

  13. たたら製鉄と鍛錬による小刀の製作

    OpenAIRE

    小松, 芳成; 後藤, 正治; 麻生, 節夫; 三浦, 敏秋; 田中, 春美; Komatsu, Yoshinari; Goto, Shoji; Aso, Setsuo; Miura, Toshiaki; Tanaka, Harumi

    2004-01-01

    Iron sand mined from Mukaihama beach in the city of Akita was applied to make "Tamahagane" based on combined use of the "Tatara-buki" and "Oroshigane" process. The Tamahagane was applied to make a small knife based on hot forging process. Initially, the iron sand was washed in water and dressed magnetically to rise iron content of the sand. After that, the iron sand was smelted by means of the "Tatara-buki" process to produce Tamahagane with lower phosphorous and sulfur contents. The Tamahaga...

  14. KCP - divine intervention?

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-07-01

    The document debates the reasons for and consequences of the abandonment of the Kemano Completion Project in British Colombia. Environmental opposition to the hydropower scheme has effectively halted operations at the site and Alcan Aluminium`s desired new power supply for its smelting plant at Kitimat have been dashed. The half-completed project will cost Alcan dear for work already carried out, under contract. It seems unlikely that the scheme will ever be completed as the environmental lobby opposing dam construction has been able to halt this duly agreed and negotiated scheme. (UK)

  15. Method of crude ore defluoridation in hydrometallurgy of beryllium, affording fluorosilicic acid

    International Nuclear Information System (INIS)

    Samojlov, V.I.; Borsuk, A.N.; Zherin, I.I.

    2006-01-01

    Results of laboratory and industrial tests conducted at Ul'ba Metallurgical Plant on leaching bertrandite - phenacite - fluorite flotation concentrate containing ∼4 wt. % beryllium in a rotary furnace using sulfuric acid are presented. The technology is shown to provide a 7.8% reduction in the net cost of beryllium production (1 kg) in the form of technical-grade Be(OH) 2 by obviating the need of smelting beryllium concentrates and alkali fluxes. Besides, the technology permits concomitant production of H 2 SiF 6 , its commercial sales promoting a 17.6% reduction in beryllium production net cost [ru

  16. The environmental rules of economic development: Governing air pollution from smelters in Chuquicamata and La Oroya

    OpenAIRE

    Orihuela, José Carlos

    2015-01-01

    Why and how do societies transform the environmental rules of economic development, or fail to do so? This article compares the experiences of Chile and Peru in the regulation of smelting activities between 1990 and 2010. Air pollution from smelters in  Chuquicamata  and  La Oroya, each emblematic of the two countries’ mining industries, did not give rise to nationally destabilising protest. Nevertheless, despite the absence of pressing discontent with pollution, the environmental rules for m...

  17. Feasibility Study of Biopower in East Helena, Montana. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, K.

    2013-02-01

    The U.S. Environmental Protection Agency (EPA) developed the RE-Powering America's Land initiative to reuse contaminated sites for renewable energy generation when aligned with the community's vision for the site. The former American Smelting and Refining Company (Asarco) smelter in East Helena, Montana, was selected for a feasibility study under the initiative. Biomass was chosen as the renewable energy resource based on the wood products industry in the area. Biopower was selected as the technology based on Montana's renewable portfolio standard (RPS) requiring utilities to purchase renewable power.

  18. A comparison of lead pollution record in Sphagnum peat with known historical Pb emission rates in the British Isles and the Czech Republic

    Science.gov (United States)

    Novak, Martin; Erel, Yigal; Zemanova, Leona; Bottrell, Simon H.; Adamova, Marie

    Vertical Pb concentration gradients and isotope ratios ( 206Pb/ 207Pb, 208Pb/ 207Pb) are reported for five 210Pb-dated Sphagnum peat profiles. The studied peat bogs are in the British Isles (Thorne Moors, England; Mull, Scotland; and Connemara, Eire) and central Europe (Ocean, northern Czech Republic; Rybarenska slat, southern Czech Republic). Both the U.K. and the Czech Republic experienced maximum Pb emissions from Ag-Pb smelting around 1880. Pb emissions from coal burning peaked in 1955 in the U.K. and in the 1980s in the Czech Republic. In both countries, use of alkyl-lead additives to gasoline resulted in large Pb emissions between 1950 and 2000. We hypothesized that peaks in Pb emissions from smelting, coal burning and gasoline burning, respectively, should be mirrored in the peat profiles. However, a more complicated pattern emerged. Maximum annual Pb accumulation rates occurred in 1870 at Ocean, 1940 at Thorne Moors, 1988 at Rybarenska slat, and 1990 at Mull and Connemara. Atmospheric Pb inputs decreased in the order Thorne Moors ≥ Ocean > Rybarenska slat > Mull > Connemara. The Ocean bog was unique in the central European region in that its maximum Pb pollution dated back to the 19th century and coincided with maximum Pb smelting at Freiberg and Pribram. In contrast, numerous previously studied sites showed no Pb accumulation maximum in the 19th century, but increasing pollution until the 1980s. It remains unclear why Ocean did not record the regional peak in Pb emissions caused by high coal and gasoline burning around 1980, while an array of nearby bogs studied previously did record the 1980 coal/gasoline peak, but no 1880 smelting peak. Mean 206Pb/ 207Pb ratios of potential pollution sources were 1.07 and 1.11 for gasoline, 1.17 and 1.17 for local ores, and 1.18 and 1.19 for coal in the U.K. and the Czech Republic, respectively. The calculated percentages of gasoline-derived Pb in peat (≤55% for the British Isles and ≤63% for the Czech Republic

  19. Remediation of biochar on heavy metal polluted soils

    Science.gov (United States)

    Wang, Shuguang; Xu, Yan; Norbu, Namkha; Wang, Zhan

    2018-01-01

    Unreasonable mining and smelting of mineral resources, solid waste disposal, sewage irrigation, utilization of pesticides and fertilizers would result in a large number of heavy metal pollutants into the water and soil environment, causing serious damage to public health and ecological safety. In recent years, a majority of scholars tried to use biochar to absorb heavy metal pollutants, which has some advantages of extensive raw material sources, low-cost and high environmental stability. This paper reviewed the definition, properties of biochar, the mechanism of heavy metal sorption by biochar and some related problems and prospects, to provide some technical support for the application of biochar into heavy metal polluted soils.

  20. Thermal stability study of melt-quenched (Fe/sub 1-x/Ni/sub x)/sub 76/B/sub 24/ amorphous ribbons

    International Nuclear Information System (INIS)

    Ashfaq, A.; Shamim, A.; Suleman, M.

    1995-01-01

    A study of thermal stability of amorphous (Fe/sub 1-x/Ni/sub x/)sub 76/B/sub 24/ (where x-0.5, 0.9) alloy ribbons, obtained from the smelt, has been undertaken by means of dynamics temperature resistivity measurements and differential thermal analysis method. RT-curves of these alloys exhibit unusual behavior, which may be due to the complexity of the crystal structures arising from heating. DTA-results show a hump and an exothermic peak, magnetic behavior of amorphous and isochronal heat treated alloys are also studied. (author)