Effect of Ca-Fe oxides additives on NOx reduction in iron ore sintering

Institute of Scientific and Technical Information of China (English)

Zhi-yuan Yu; Xiao-hui Fan; Min Gan; Xu-ling Chen

2017-01-01

As the emission control regulations get stricter, the NOx reduction in the sintering process becomes an important environmental concern owing to its role in the formation of photochemical smog and acid rain. The NOx emissions from the sintering machine account for 48% of total amount from the iron and steel industry.Thus, it is essential to reduce NOx emissions from the sintering machine, for the achievement of clean production of sinter.Ca-Fe oxides, serving as the main binding phase in the sinter, are therefore used as additives into the sintering mixture to reduce NOx emissions.The results show that the NOx re-duction ratio achieves 27.76% with 8% Ca-Fe oxides additives since the Ca-Fe oxides can advance the ig-nition and inhibit the nitrogen oxidation compared with the conventional condition.Meanwhile, the exist-ence of Ca-Fe oxides was beneficial to the sinter quality since they were typical low melting point com-pounds.The optimal mass fraction of Ca-Fe oxides additives should be less than 8% since the permeability of sintering bed was significantly decreased with a further increase of the Ca-Fe oxides fines, inhibiting the mineralization reaction of sintering mixture.Additionally, the appropriate particle size can be obtained when mixing an equal amount of Ca-Fe oxides additives of -0.5 mm and 0.5-3.0 mm in size.

Control of the flame front advance in a sintering bed of iron ores; Control del avance del frente de llama en el lecho de sinterizacion de minerales de hierro

Energy Technology Data Exchange (ETDEWEB)

Cores, A.; Mochon, J.; Ruiz-Bustinza, I.; Parra, R.

2010-07-01

A sintering pan of 40 cm cubed is loaded with a mixture of iron ores, limestone and coke weighing 110 kg in a sintering pilot plant. In this sintering pan, a series of thermocouples have been introduced at different depths. Tests have been carried out to study the width of the combustion zone and the maximum temperature of the flame front across the sintering bed. For the analysis of the results, a data acquisition system was used. This consisted of two modules connected in serie, for performing the analogue-digital conversion. The analogue entry point is the exit point of the thermocouples and the digital exit point was the temperature average. A computer was used for conserving and storing the data and for carrying out interpolations, simulating the state and evolution of the flame front across the bed. (Author) 21 refs.

Assessment of polyphase sintered iron-cobalt-iron boride cermets

International Nuclear Information System (INIS)

Nowacki, J.; Pieczonka, T.

2004-01-01

Sintering of iron, cobalt and boron powders has been analysed. As a result iron-iron boride, Fe-Fe 2 B and iron/cobalt boride with a slight admixture of molybdenum, Fe - Co - (FeMoCo) 2 B cermets have been produced. Iron was introduced to the mixture as the Astalloy Mo Hoeganaes grade powder. Elemental amorphous boron powder was used, and formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Dilatometry was chosen to control basic phenomena taking place during multiphase sintering of investigated systems. The microstructure and phase constituents of sintered compacts were controlled as well. The cermets produced were substituted to: metallographic tests, X-ray analysis, measurements of hardness and of microhardness, and of wear in the process of sliding dry friction. Cermets are made up of two phases; hard grains of iron - cobalt boride, (FeCo) 2 B (1800 HV) constituting the reinforcement and a relatively soft and plastic eutectic mixture Fe 2 B - Co (400-500 HV) constituting the matrix. (author)

Sintering of manganese ore in natura with different additions on activated carbon

International Nuclear Information System (INIS)

Lima, M.M.F.; Mapa, T.F.M.; Lima, R.M.F.

2016-01-01

Full text: The shortage of high grade manganese ore and the importance of economically viable processes suggest a necessity of the recovery of ore residues. So, this work presents a route to obtain by-products of economic interest from manganese ore residues in bench scale. The objective was the sintering of manganese ore in natura using a particle size below 0,037μm with different additions of activated carbon. For this, the fine residues were calcined at 800°C during 60 minutes, homogenized in an agate mortar with 12% humidity and additions of 9 and 12% of activated carbon. After homogenization, the sintering process was carried out at 1145°C and 1155°C during 5, 15 and 30 minutes at natural air. The products sintered were characterized by bulk density, BET surface area, OM, SEM / EDS and diffraction X-rays. During the calcination of the ore, the mass loss was (15.16 ± 0.02)% due to the elimination of volatiles and water. The surface area of the ore was reduced due to the diffusion process that occurred during sintering. While, the bulk density values had little variation, around (3.51 ± 0.06)g/cm³. The analyses of micro-regions EDS showed that the matrix is a silicate with a high Mn content. It was identified yet, other silicates with different proportions of Si, Al, Ti, Na, Mn, Mg and Ca. (author)

Sintering of manganese ore in natura with different additions on activated carbon

Energy Technology Data Exchange (ETDEWEB)

Lima, M.M.F.; Mapa, T.F.M.; Lima, R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

2016-07-01

Full text: The shortage of high grade manganese ore and the importance of economically viable processes suggest a necessity of the recovery of ore residues. So, this work presents a route to obtain by-products of economic interest from manganese ore residues in bench scale. The objective was the sintering of manganese ore in natura using a particle size below 0,037μm with different additions of activated carbon. For this, the fine residues were calcined at 800°C during 60 minutes, homogenized in an agate mortar with 12% humidity and additions of 9 and 12% of activated carbon. After homogenization, the sintering process was carried out at 1145°C and 1155°C during 5, 15 and 30 minutes at natural air. The products sintered were characterized by bulk density, BET surface area, OM, SEM / EDS and diffraction X-rays. During the calcination of the ore, the mass loss was (15.16 ± 0.02)% due to the elimination of volatiles and water. The surface area of the ore was reduced due to the diffusion process that occurred during sintering. While, the bulk density values had little variation, around (3.51 ± 0.06)g/cm³. The analyses of micro-regions EDS showed that the matrix is a silicate with a high Mn content. It was identified yet, other silicates with different proportions of Si, Al, Ti, Na, Mn, Mg and Ca. (author)

EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

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Juan Enrique Villalva A.

2015-11-01

Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

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Peter J. Williams

2010-04-01

Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

China's emergence as the world's leading iron-ore-consuming country

Science.gov (United States)

Kirk, W.S.

2004-01-01

China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

Granulation of coke breeze fine for using in the sintering process

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Mohamed F.M.

2010-01-01

Full Text Available Coke breeze is the main fuel used in the sintering process. The value of -3+1 mm. represents the most favorable particle size for coke breeze in the sintering process. About 20% of total coke fines (-0.5 mm are produced during different steps of preparation. Introducing these fines during the sintering process proves to be very harmful for different operating parameters. Thus ,this study aims at investigating the production of granules resulting from these fines using molasses as organic binder and its application in sintering of an iron ore. The results showed that the granules having the highest mechanical properties were obtained with 14.5 wt % molasses addition. The sintering experiments were performed by using coke breeze in different shapes (-3+1 mm in size, coke breeze without sieving and coke breeze granules -3+1 mm. The reduction experiments, microscopic structure and X-ray analysis for the produced sinter were carried out. The results revealed that, all sinter properties (such as shatter test, productivity of sinter machine and blast furnace, reduction time and chemical composition for produced sinter by using coke breeze with size -3+1 mm and coke breeze granules were almost the same. The iron ore sinter which was produced by using coke breeze without sieving yielded low productivity for both sinter machine and blast furnace. Furthermore, using coke breeze without sieving in sintering of an iron ore decreases the vertical velocity of sinter machine and increases the reduction time.

Unintentional production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes.

Science.gov (United States)

Li, Sumei; Liu, Guorui; Zheng, Minghui; Liu, Wenbin; Li, Jinhui; Wang, Mei; Li, Changliang; Chen, Yuan

2017-06-05

Iron ore sintering (SNT) processes are major sources of unintentionally produced chlorinated persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). However, few studies of emissions of brominated POPs, such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), during SNT have been performed. Stack gas and fly ash samples from six typical SNT plants in China were collected and analyzed to determine the concentrations and profiles of PCDD/Fs, PCBs, PCNs, PBDD/Fs, and PBDEs, as well as any correlations among these compounds. The PCDD/F, PCB, PCN, PBDD/F, and PBDE emission factors were 2.47, 0.61, 552, 0.32, and 107μgt -1 , respectively (109, 4.07, 10.4, 4.41 and 0.02ng toxic equivalents t -1 , respectively). PCBs were the most abundant compounds by mass, while PCNs were the next most abundant, contributing 51% and 42% to the total POP concentration, respectively. However, PCDD/Fs were the dominant contributors to the chlorinated and brominated POP toxic equivalent concentrations, contributing 89% to the total toxic equivalent concentration. The PCDD/F and other chlorinated and brominated POP concentrations were positively correlated, indicating that chlorinated and brominated POP emissions could be synergistically decreased using the best available technologies/best environmental practices already developed for PCDD/Fs. Copyright © 2017 Elsevier B.V. All rights reserved.

Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry

African Journals Online (AJOL)

Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry was studied as a function of the microstructure developed by austempering at 380 and 300°C for different exposure time in the slurry. The corrosion rates of the ADI balls immersed in the iron ore slurry was determined using weight loss method.

NUMERICAL EVALUATION OF THE EFFECTS OF SOFT-MELTING PROPERTIES ON THE KINETIC OF (CAFE2 O4 -CA2 FE2 O5 FORMATION IN THE IRON ORE SINTERING PROCESS

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José Adilson de Castro

2013-03-01

Full Text Available This paper presents a mathematical model able to predict the influence of soft-melting properties of the blend of raw materials used in the iron ore sintering process in the kinetic formation of calcium ferrite and di-calcium ferrite constituents. The model is based on the simultaneous solution of transport equations of Momentum, energy and chemical species in multiphase multicomponent systems coupled with the chemical reactions kinetics and phase transformations that occur within the sinter bed. The numerical solution is obtained using the finite volume method and the model is validated using monitoring data from an industrial scale sintering plant. After validation, the model was used to predict processing conditions using raw materials with different soft-melting properties. Results indicate that the temperatures of starting soft-melting, shrinkage and melting range are the main parameters to be controlled in order to attain liquid phases formation responsible to confer good mechanical and reducibility properties for the sinter product. In this study was found that raw materials with high soft-melting temperature and wilder temperature of mushy zone could decrease up to 30% the calcium ferrites formation and hence deteriorates the metallurgical properties of the sinter.

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

Sintering studies on iron-carbon-copper compacts

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Perianayagam Philomen-D-Anand Raj

2016-01-01

Full Text Available Sintered Iron-Carbon-Copper parts are among the most widely used powder metallurgy product in automobile. In this paper, studies have been carried out to find out the sintering characteristics of iron-carbon-copper compacts when sintered in nitrogen atmosphere. The effects of various processing parameters on the sintering characteristics were studied. The various processing parameters considered were compaction pressure, green density and sintering temperature. The sintering characteristics determined were sintered density, porosity, dimensional change, micro hardness and radial crush strength. The results obtained have been discussed on the basis of micro structural observations. The characteristics of SEM fractography were also used to determine the mechanism of fracture. The fracture energy is strongly dependent on density of the compact.

Experimental research on the characteristics of softening and melting of iron ores as significant factor of influence on gas permeability of blast furnace charge

International Nuclear Information System (INIS)

Branescu, E; Blajan, A O; Constantin, N

2015-01-01

It is widely accepted as a cohesive zone is directly influenced by softening and melting properties of iron ores, preparations (crowded, pellets, which represents about 90%, of the loads with metal furnace intake), or uncooked (raw ores ranked). Important results can be obtained through the study of behavior of ferrous materials at temperatures above 1000 ° C. Starting from research methods presented in the literature, this paper presents itself in carrying out their own laboratory experiments, conducted with the aim of analysing the softening and melting properties of sinter iron cores. (paper)

Iron isotope fractionation during hydrothermal ore deposition and alteration

Science.gov (United States)

Markl, Gregor; von Blanckenburg, Friedhelm; Wagner, Thomas

2006-06-01

Iron isotopes fractionate during hydrothermal processes. Therefore, the Fe isotope composition of ore-forming minerals characterizes either iron sources or fluid histories. The former potentially serves to distinguish between sedimentary, magmatic or metamorphic iron sources, and the latter allows the reconstruction of precipitation and redox processes. These processes take place during ore formation or alteration. The aim of this contribution is to investigate the suitability of this new isotope method as a probe of ore-related processes. For this purpose 51 samples of iron ores and iron mineral separates from the Schwarzwald region, southwest Germany, were analyzed for their iron isotope composition using multicollector ICP-MS. Further, the ore-forming and ore-altering processes were quantitatively modeled using reaction path calculations. The Schwarzwald mining district hosts mineralizations that formed discontinuously over almost 300 Ma of hydrothermal activity. Primary hematite, siderite and sulfides formed from mixing of meteoric fluids with deeper crustal brines. Later, these minerals were partly dissolved and oxidized, and secondary hematite, goethite and iron arsenates were precipitated. Two types of alteration products formed: (1) primary and high-temperature secondary Fe minerals formed between 120 and 300 °C, and (2) low-temperature secondary Fe minerals formed under supergene conditions (illustrates the potential of the new technique in deciphering ore formation and alteration processes. Isotope ratios are strongly dependent on and highly characteristic of fluid and precipitation histories. Therefore, they are less suitable to provide information on Fe sources. However, it will be possible to unravel the physico-chemical processes leading to the formation, dissolution and redeposition of ores in great detail.

Challenges facing the North American iron ore industry

Science.gov (United States)

Jorgenson, J.D.

2005-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

Natural resources sustainability: iron ore mining

International Nuclear Information System (INIS)

De La Torre de Palacios, Luis

2011-01-01

In the present article, a new tool to determine environmental sustainability, the energy impact index (EII) was developed to classify different iron mine projects according to two main parameters including energy consumption and CO 2 emissions. The EII considers the characteristics of the mineral (such as the quality, size, hardness, iron ore grade, reducibility, mineral/waste rate, and type of deposit), mining processes (type of exploitation, ore processing, available technology), and transportation (distance to cover).

Factors Affecting Ballability of Mixture Iron Ore Concentrates and Iron Oxide Bearing Wastes in Metallurgical Processing

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Mfon Udo

2018-05-01

Full Text Available Iron oxide bearing wastes (IROBEWAS are produced at every segment of processing stage of sinter, molten iron and steel production. They are hard to handle and in many cases are stockpiled only to be a source of environmental pollution but can be balled into pellets. Pellet of good ballability values are transportable and recyclable as they can withstand stress they will encounter without disintegrating back to dust. But ballability is affected by some factors like the grain sizes of the materials, the moisture and binder contents of the ball mix, wettability of the balled materials and the processing perimeters of the granulator. The objective of this research work is to investigate the factors affecting ballability of mixture of iron ore concentrates and iron oxide bearing wastes (IROBEWAS in metallurgical processing. The parameters under consideration were grain size of materials, the moisture contents, the speed of balling disc, IROBEWAS and Bentonite (Binder contents of the balled mix. This was carried out by balling different volume fractions of mix containing iron oxide concentrate and IROBEWAS using a balling disc and testing the resulting balls for green compressive strength using universal testing machine. It was found that the ballability of the mixture of iron ore concentrate and IROBEWAS increases as grain sizes of the materials reduce but increases as the moisture contents and IROBEWAS content increase up to an optimum value of moisture content in the mix before it starts to reduce. The ballability also increases as the speed of the granulator (Balling disc increases within the limit of this work. It was also observed that there was an increase in ballability with slight increase in bentonite content in the mix.

Sinterization of manganese ore tailings under argon atmosphere

Energy Technology Data Exchange (ETDEWEB)

Valduga, M.M.F.; Lima, F.; Lima, R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

2014-07-01

Manganese is an element widely used in Metallurgy, however the Brazilian reserves has low grade. The aim of this work was to obtain and characterize the sinters from manganese ore tailings. The fines (less than 400⧣) were calcinated (800°C - 3600s) and homogenized with activated charcoal (7 and 10%) and CaO (5 and 10%). The sintering were carried out at 1135, 1140 and 1145°C during 7200 and 14400s under argon atmosphere. The sintered products were characterized by EDS analysis, BET surface area, apparent density, X-rays diffraction and SEM/EDS. The surface area was 0.03m2/g. The alkali element present (potassium) justified the low melting point of waste (1140°C). Due to the chemical complexity of the tailings, several phases were characterized in the products: pores, silicates with high content of manganese in the matrix, other silicates with different proportions of Al, Mn, Mg and Ca, pure Fe, SiO2, etc. (author)

Effect of Organic Binders on The Quality of Manganese Ore Sinter Fines Briquettes

International Nuclear Information System (INIS)

Mohamed, F. M.; Ahmed, Y.M.Z.; Shalabi, M. E. H.

2004-01-01

Sinai Manganese Company imports the manganese ore sinter from abroad for ferromanganese alloy production. Large quantities of manganese ore sinter fines are produced in this process. These fines must be agglomerated to a suitable size in order to be reused for charging the electric arc furnace. The aim of this work is studying the briquetting ability of these fines using organic binders such as starch and bitumen. The results showed that, the suitable briquettes were produced with the addition of 5 % of starch and 20% H 2 O under pressure 3 ton/cm 2 or 8 % bitumen under pressure 4 ton/cm 2 and 3 days curing time

Isolation and identification of iron ore-solubilising fungus

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Damase Khasa

2010-09-01

Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca₃(PO₄₂in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

Science.gov (United States)

Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

2011-02-01

High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

Effective Processing of the Iron Ores

Science.gov (United States)

Kuskov, Vadim; Kuskova, Yana; Udovitsky, Vladimir

2017-11-01

Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats): comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Effective Processing of the Iron Ores

Directory of Open Access Journals (Sweden)

Kuskov Vadim

2017-01-01

Full Text Available Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats: comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Utilisation of iron ore tailings as aggregates in concrete

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Francis Atta Kuranchie

2015-12-01

Full Text Available Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

The North American iron ore industry: a decade into the 21st century

Science.gov (United States)

Jorgenson, John D.; Perez, A. A

2011-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

Experimental study and modelling of iron ore reduction by hydrogen

International Nuclear Information System (INIS)

Wagner, D.

2008-01-01

In an effort to find new ways to drastically reduce the CO 2 emissions from the steel industry (ULCOS project), the reduction of iron ore by pure hydrogen in a shaft furnace was investigated. The work consisted of literature, experimental, and modelling studies. The chemical reaction and its kinetics were analysed on the basis of thermogravimetric experiments and physicochemical characterizations of partially reduced samples. A specific kinetic model was designed, which simulates the successive reactions, the different steps of mass transport, and possible iron sintering, at the particle scale. Finally, a 2-dimensional numerical model of a shaft furnace was developed. It depicts the variation of the solid and gas temperatures and compositions throughout the reactor. One original feature of the model is using the law of additive characteristic times for calculating the reaction rates. This allowed us to handle both the particle and the reactor scale, while keeping reasonable calculation time. From the simulation results, the influence of the process parameters was assessed. Optimal operating conditions were concluded, which reveal the efficiency of the hydrogen process. (author)

Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

Science.gov (United States)

Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

2015-04-01

India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

Iron-ore resources of the United States including Alaska and Puerto Rico, 1955

Science.gov (United States)

Carr, Martha S.; Dutton, Carl E.

1959-01-01

The importance of iron ore, the basic raw material of steel, as a fundamental mineral, resource is shown by the fact that about 100 million long tons of steel is used annually in the economy of the United States, as compared with a combined total of about 5 million long tons of copper, lead, zinc, and aluminum. Satisfying this annual demand for steel requires about 110 million tons of iron ore and 70 million tons of scrap iron and steel. The average annual consumption of iron ore in the United States from 1951 to 1955, inclusive, was about 110 million long tons, which is about twice the annual average from 1900 to 1930. Production of iron ore in the United States in this 5-year period averaged approximately 100 million long tons annually, divided by regions as follows (in percent): Lake Superior, 84.1; southeastern, 6.7; western, 6.7; northeastern, 1.4; and central and gulf, 1.1. Mining of iron ore began in the American Colonies about 1619, and for 225 years it was limited to eastern United States where fuel and markets were readily available. Production of iron ore from the Lake Superior region began in 1846; the region became the leading domestic source by 1890, and the Mesabi range in Minnesota has been the world's most productive area since 1896. Proximity of raw materials, water transportation, and markets has resulted in centralization of the country's iron and steel industry in the lower Great Lakes area. Increased imports of iron ore being delivered to eastern United States as well as demands for steel in nearby markets have given impetus to expansion in the steel-making capacity in this area. The four chief iron-ore minerals - hematite, liminite, magnetite, and siderite - are widely distributed but only locally form deposits of sufficient tonnage and grade to be commercially valuable at the present time. The iron content of these minerals, of which hematite is the most important, ranges from 48 percent in siderite to 72 percent in magnetite, but as these

Influence of the Moisture Content on the Flowability of Fine-Grained Iron Ore Concentrate

OpenAIRE

C. Lanzerstorfer; M. Hinterberger

2017-01-01

The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. Subsequently, physical separation processes are applied to concentrate the iron ore. The fine-graine...

Corrosion behavior of austempered ductile iron (ADI) in iron ore slurry

African Journals Online (AJOL)

ADI austempered at higher temperature showed better corrosion resistance than the ..... temperature and time on corrosion behaviour of ductile iron in chloride and acidic ... iron ore in ball mills, Transactions of the Indian Institute of Metals, Vol.

Modifier free supercritical fluid extraction of uranium from sintered UO2, soil and ore samples

International Nuclear Information System (INIS)

Kanekar, A.S.; Pathak, P.N.; Acharya, R.; Mohapatra, P.K.; Manchanda, V.K.

2011-01-01

Direct extraction of uranium from different samples viz. sintered UO 2 , soil and ores was carried out by modifier free supercritical fluid using tri-n-butyl phosphate-nitric acid (TBP-HNO 3 ) adduct as extractant. These studies showed that pre-equilibration with more concentrated nitric acid helps in better dissolution and extraction of uranium from sintered UO 2 samples. Modifier free supercritical fluid extraction appears attractive with respect to minimization of secondary wastes. This method resulted 80-100% extraction of uranium from different soil/ore samples. The results were confirmed by performing neutron activation analysis of original (before extraction) and residue (after extraction) samples. (author)

Mineralogical study of zard koh and kulli koh iron ore deposits of pakistan

International Nuclear Information System (INIS)

Khoso, S.A.; Abro, M.I.

2017-01-01

Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited) is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SEM (Scanning Electron Microscope) attached with EDS (Energy Dispersive Spectroscope) and SM (Stereomicroscope) techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques. (author)

Beneficiation and agglomeration of manganese ore fines (an area so important and yet so ignored)

Science.gov (United States)

Sane, R.

2018-01-01

. Sinters have already been proved to bring enormous technical benefits in smelting operation. However small mine owners find it practically impossible to set up a small beneficiation and/or sintering unit at mine site. Recent advances in dry or pneumatic separation which depends on density difference between valuable mineral and gangue/waste rock, are proving to be advantageous & effective because of its small capacity. Capacity is 5 T/hr or 10 T/hr. When applied to low grade high silica Iron ores Iron content has been found to be enhanced by 8 to 10 % from 48% to 58 %, with overall wt. recovery of 60 to 70 %. Recently this technique was applied to low grade siliceous Mn ore with very encouraging results. Mn content has been found to be enhanced from 25 +/- 2 % to 37 +/- 2 % and with 50 to 65% wt. recovery. Size of feed is restricted to (i) 6 to 25 mm and (ii) 2 to 6 mm. Due to Modular design it is possible to put up units from 50 TPD to 800 TPD capacity.

Fundamentals of fast reduction of ultrafine iron ore at low temperature

Institute of Scientific and Technical Information of China (English)

Pei Zhao; Peimin Guo

2008-01-01

Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

Ferrite grade iron oxides from ore rejects

Indian Academy of Sciences (India)

Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical ...

94423-6883 Evaluation of Iron Ore Deposits in Elayiram Pannai

African Journals Online (AJOL)

Michael Horsfall

ABSTRACT: 2D Electrical Resistivity Imaging (ERI) investigation is suitable method to determine the geotechnical problems and it is used to identify the iron ore deposits. 2D. Electrical Resistivity Imaging with Wenner array was conducted within the iron ore deposits area in Elayiram Pannai, Virudhunagar District, ...

Pelletized vs. natural iron ore technology: energy, labor, and capital changes. Final report

Energy Technology Data Exchange (ETDEWEB)

Kakela, P.

1978-09-01

Total energy requirements per ton of iron-in-ore for natural and pelletized ore were calculated by a hybrid energy analysis. Energy requirements for ore preparation were subsequently considered as one energy input (embodied) to blast furnaces. Total energy requirements per ton molten iron were calculated for each year from 1955 through 1975 to identify changes attributable to the shift in iron ore preparation. Four results were found. (1) In practice, the lean ores are energetically superior. Pelletized ore requires more energy at the mine than natural ore, but pellets produce offsetting energy savings in the blast furnace. (2) Labor changes followed a similar pattern: man-hours per ton of molten iron increased at the mine with pelletization, but decreased at the blast furnance. Net labor required per ton of molten iron has decreased with pelletization. (3) Capital investments per ton of molten iron have increased greatly at iron ore mines with pelletization and decreased moderately at blast furnaces. New capital investment per ton of molten iron has increased with pelletization. (4) In the iron and steel industry, relatively low-priced energy held a substantial advantage over high-priced labor between 1950 and 1969. The industry, however, discovered that capital investments in pellet plants could save both labor and energy up to 1963; after 1963 capital and energy weresubstituted for labor. A sharp reversal of substitutional advantage occurred in 1970; energy jumped to the most costly factor. Thus capital presently shows a strong substitutional advantage over high-priced energy and intermediately-priced labor.

Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

Directory of Open Access Journals (Sweden)

SULTAN AHMED KHOSO

2017-10-01

Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

Dolochar as a reductant in the reduction roasting of iron ore slimes

Science.gov (United States)

Rath, Swagat S.; Rao, Danda Srinivas

2017-12-01

The present investigation examines the viability of dolochar, a sponge iron industry waste material, as a reductant in the reduction roasting of iron ore slimes, which are another waste generated by iron ore beneficiation plants. Under statistically determined optimum conditions, which include a temperature of 900°C, a reductant-to-feed mass ratio of 0.35, and a reduction time of 30-45 min, the roasted mass, after being subjected to low-intensity magnetic separation, yielded an iron ore concentrate of approximately 64wt% Fe at a mass recovery of approximately 71% from the feed iron ore slime assaying 56.2wt% Fe. X-ray diffraction analyses indicated that the magnetic products contain magnetite and hematite as the major phases, whereas the nonmagnetic fractions contain quartz and hematite.

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

Indian Academy of Sciences (India)

Central Iran; iron-apatite ore; Kiruna-type; Posht-e-Badam Block; REE geochemistry. J. Earth Syst ... ferent ore genesis models have been proposed for ...... volatile-rich magma systems stress the important .... Laco magnetite flow deposits, northern Chile: An up-to- ... economic report on iron ore prevision of the Esfahan steel.

Production of Schwarzmoeller briquets from weakly caking black coal and iron ore

Energy Technology Data Exchange (ETDEWEB)

Naundorf, W.

1986-01-01

Laboratory production is explained of coal and iron ore briquets suitable for metallurgy, using type 33 weakly caking black coal, iron ore concentrates from 3 Soviet mines and sulfite lye as binder. Coal and ore were finely ground to 0.3/0.0 mm grain size, briquetted at high pressure of 150 MPa and at 80 C temperature. The sulfite lye binder content ranged from 4 to 10% in the briquet mixture. Briquets were thermally treated up to 1000 C; the resulting coke lumps (Schwarzmoeller briquets) were analyzed for compression and abrasion strength. Detailed graphs of briquet and coke lump quality parameters are provided. The study shows that high quality metallurgical coke lumps are obtained by briquetting mixtures of black coal and iron ore in a mixture of about 70:30 with 4 to 9% addition of sulfite binder. Compression strength of coke lumps exceeded 35 MPa. The minimum black coal-iron ore mass relation for producing metallurgical coke lumps was 30:70 using 2 types of iron ore concentrates. The influence of adding limestone to the briquetting mixture and of coking conditions resembling the horizontal chamber oven process is also investigated. 5 references.

The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit

Directory of Open Access Journals (Sweden)

Seyyed Ali Nezamolhosseini

2017-01-01

Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone.  Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.

International convention on clean, green and sustainable technologies in iron and steel making

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

The presentations (overheads/viewgraphs) discussed energy efficiency and conservation in iron and steel making, air pollution control, carbon trading, reclamation of iron ore mines, utilisation of low grade coal and iron ore, Corex and Finex processes, HIsmelt, sinter technology, energy recovery, reduction gas from coal, coal gasification and syngas based DRI, and resettlement of people.

Direct Biohydrometallurgical Extraction of Iron from Ore

Energy Technology Data Exchange (ETDEWEB)

T.C. Eisele

2005-10-01

A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

Influence of attrition variables on iron ore flotation

Directory of Open Access Journals (Sweden)

Fabiana Fonseca Fortes

Full Text Available Abstract The presence of slimes is harmful to the flotation process: the performance and consumption of reagents are negatively affected. Traditionally, the desliming stage has been responsible for removing slimes. However, depending on the porosity of the mineral particles, desliming may not be sufficient to maximize the concentration results. An attrition process before the desliming operation can improve the removal of slime, especially when slimes cover the surface and/or are confined to the cavities/pores of the mineral particles. Attrition is present in the flowcharts of the beneficiation process of phosphate and industrial sand (silica sand. Research has been undertaken for its application to produce pre-concentrates of zircon and iron ore. However, there is still little knowledge of the influence of the attrition variables on the beneficiation process of iron ore. This study presents a factorial design and analysis of the effects of these variables on the reverse flotation of iron ore. The standard of the experimental procedures for all tests included the attrition of pulp, under the conditions of dispersion, desliming and flotation. The parameter analysed (variable response was the metallurgical recovery in reverse flotation tests. The planning and analysis of the full factorial experiment indicated that with 95% reliability, the rotation speed of the attrition cell impeller was the main variable in the attrition process of the iron ore. The percentage of solid variables in the pulp and the time of the attrition, as well as their interactions, were not indicated to be significant.

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry

Science.gov (United States)

Mokhtari, Mir Ali Asghar; Zadeh, Ghader Hossein; Emami, Mohamad Hashem

2013-06-01

Rare earth elements in apatites of different ore types show characteristic patterns which are related to different modes of formation of the ores. Most of the apatite-bearing iron ores are associated with alkaline magmas with LREE/HREE fractionation varying from moderate to steep. Iron-apatite deposits in Posht-e-Badam Block (Central Iran) have a high concentration of REE (more than 1000 ppm up to 2.5%), and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. This REE pattern is typical of magmatic apatite and quiet distinct from sedimentary apatites (phosphorites) which have a low REE contents and Ce negative anomalies. On the other hand, they are comparable to the REE patterns of apatites in Kiruna-type iron ores in different parts of the world. The REE patterns of apatites, iron-apatite ores and iron ores are similar and only have different REE contents. This similarity indicates a genetic relation for these rocks. Most of the iron-apatite deposits in Central Iran have similar REE patterns too, which in turn show a genetic relation for all of these deposits. This similarity indicates a similar origin and processes in their genesis. There are some small intrusions around some of the iron-apatite deposits that are petrographically identified as syenite and gabbro. These intrusions also have REE patterns similar to that of iron-apatite ores. This demonstrates a genetic relation between these intrusions and iron-apatite ores. The REE patterns of apatites in different deposits of Posht-e-Badam Block iron-apatite ores show an affinity to alkaline to sub-alkaline magmas and rifting environment. The alkaline host rocks of Central Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE-NNW fault lines). A probable source for this large scale ore forming processes is relatively low partial melting of mantle rocks. The ores have originated by magmatic differentiation as a late phase in the volcanic cycle

Assessment of exposure to PCDD/F, PCB, and PAH at a basic oxygen Steelmaking (BOS) and an iron ore sintering plant in the UK.

Science.gov (United States)

Jackson, Kevin; Aries, Eric; Fisher, Raymond; Anderson, David R; Parris, Adrian

2012-01-01

An assessment was carried out at a UK integrated steelworks to investigate the exposure of workers via inhalation to dioxins [polychlorinated dibenzo-p-dioxins (PCDD/F)], polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAH) including benzo[a]pyrene (B[a]P). Investigations focused on a basic oxygen steelmaking (BOS) plant and an iron ore sintering plant. The highest concentrations of PCDD/F and dioxin-like PCB were found at the BOS vessels and sinter strand area at the BOS and sinter plant, respectively. A risk assessment was carried out by comparing the daily intake of PCDD/F and PCB via inhalation with the recommended tolerable daily intake (TDI) proposed by the World Health Organisation (WHO). For the most exposed category of worker in this study (i.e. sinter plant workers inside the strand area), the estimated daily intake via inhalation was estimated to be 0.25 pg WHO-toxic equivalent concentrations (TEQ) kg(-1) body weight (bw). Considering that the average UK adult exposure to PCDD/F from the diet is 1.8 pg WHO-TEQ kg(-1) bw day(-1), the results indicated that the estimated daily intake of PCDD/F and PCB via inhalation for sinter plant workers would not result in the recommended range of the TDI (1-4 pg WHO-TEQ kg(-1) bw day(-1)) being exceeded. Cancer risks for a 40-year occupational exposure period were determined by multiplying the estimated intake by the inhalation cancer potency factor for 2,3,7,8-tetrachlorodibenzo-p-dioxin. For the most exposed category of worker, cancer risks from exposure to PCDD/F and PCB ranged from 2.5 × 10(-6) to 5.2 × 10(-5). Under most regulatory programmes, excess cancer risks between 1.0 × 10(-6) and 1.0 × 10(-4) indicate an acceptable range of cancer risk, suggesting a limited risk from PCDD/F and PCB exposure for workers in the sinter plant. With regard to PAH, B[a]P concentrations were typically plant and the BOS plant. In several cases, particularly at the sinter plant, B[a]P concentrations

Development of the Facility for Transformation of Magnetic Characteristics of Weakly Magnetic Oxidized Iron Ores Related to Improvement of Technologies for Iron Ore Concentrate Production

Directory of Open Access Journals (Sweden)

Ponomarenko, O.M.

2016-01-01

Full Text Available New facility for continuous registration of iron ore magnetization depending on temperature by heating of iron ores upon reducing conditions was created. Facility allows to register the processes of transformation of weakly magnetic minerals into strongly magnetic ones under the influence of reducing agents and temperature, as well as to determine the Curie temperature of the minerals. Using created facility it was shown, that heating of goethite and hematite in the presence of 4 % of starch in the temperature range of 300—650 °С leads to significant increase of magnetization of the samples. X-Ray diffraction confirmed that under indicated conditions the structure of hematite and goethite is transformed into magnetite structure. Obtained results open up new possibilities for the development of effective technologies for oxidized iron ore beneficiation.

Pilot plant experience in electron-beam treatment of iron-ore sintering flue gas and its application to coal boiler flue gas cleanup

International Nuclear Information System (INIS)

Kawamura, K.

1984-01-01

The present development status of the electron-beam flue gas treatment process, which is a dry process capable of removing SOx and NOx simultaneously, is described. The most advanced demonstration of this process was accomplished with a pilot plant in Japan where the maximum gas flow rate of 10,000 Nm 3 /h of an iron-ore sintering machine flue gas was successfully treated. The byproduct produced in this process is collected as a dry powder which is a mixture of ammonia sulfate and ammonium nitrate and is saleable as a fertilizer or a fertilizer component. A preliminary economic projection showed that this process costs less than the lime scrubber which removes SOx but does not remove NOx. Tests using simulated coal combustion gases suggest that this process will be applicable to coal-fired boiler flue gas treatment as well. However, tests on actual coal-fired flue gases are still required for commercial application decisions. A process development unit program consisting of the design, construction and testing of actual coal-fired power station flue gases is underway in the U.S.A. The design and engineering of the test plant is far advanced and the construction phase will be launched in the very near future. (author)

Utilisation of iron ore tailings as aggregates in concrete

OpenAIRE

Francis Atta Kuranchie; Sanjay Kumar Shukla; Daryoush Habibi; Alireza Mohyeddin

2015-01-01

Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength we...

Applicability of attrition of iron ore in floating

International Nuclear Information System (INIS)

Fortes, Fabiana Fonseca

2010-01-01

The aim of this study is to investigate the possibility to increase metal recovery in the flotation of iron ore with the implementation of a stage of scrubbing followed by dispersion. The minerals in question stems from two mines located in the western portion of the Iron Quadrangle and differ mainly with respect to the percentage of hematite and porous and the presence of aggregated masses. These characteristics were compared to those of other minerals that have succeeded with the adoption of this technique. Tests were conducted at bench scale scrubbing, desliming and concentration by flotation with the blend of ore from both mines. Were varied stirring time and pH. The chemical results of desliming and flotation products in the different conditions were compared. The presence of porous hematite is relevant in a mine, mainly due to the occurrence of earthy goethite, alumina carrier of the contaminant. The step desliming is insufficient for the removal of harmful sludge flotation. Laboratory experiments showed that the scrubbing of the pulp of iron ore of Minas de Capitao do Mato and Tamandua, agitated for 10 minutes followed by desliming amid scattered, promotes increased metal recovery by about 17% and increases the selectivity of 40 % compared to the results of the scrubbing and without dispersion. The scrubbing of hematite ore followed by desliming amid scattered can bring gains in improving the quality of pellet feed fine if deployed industrially. (author)

Multistage dilute acid leaching of a medium grade iron ore to super-concentrate

Directory of Open Access Journals (Sweden)

Adeleke A.A.

2014-01-01

Full Text Available The phosphorous laden Koton Karfe iron ore is a medium grade iron ore deposit in Nigeria that can be upgraded as a super-concentrate for use at the Aladja Steel Midrex plant. The 75 μm size sample fraction of the ore was preconcentrated with shaking table and leached in the oven at atmospheric pressure with dilute hydrochloric acid in single and multistage leaching sequences of H2O-HCl-H2O and HCl-H2O-H2O. The as-received, as-tabled and asleached samples were then subjected to X-ray fluorescence and microscopic analyses. The results obtained showed that the H2O-HCl-H2O route produced a higher grade concentrate that assayed 68.54% Fe indicating about 58% upgrade in iron content; while the phosphorus and sulphur contents were reduced by about 77 and 99.6% respectively. In addition, the silicon, manganese, and titanium contents were drastically reduced, while potassium was completely eliminated. The upgrade of iron content in the ore to 68.54% and the drastic reduction in phosphorous and sulphur contents has thus rendered the Koton Karfe iron ore suitable for use as a super concentrate for the Aladja steel plant direct reduction iron making process.

Development of import subtituting technologies for increasing productivity of sintering machines and strength of agglomerates

Directory of Open Access Journals (Sweden)

В. Л. Трушко

2016-11-01

Full Text Available A problem of industrial fluxed agglomerates self-destruction in the process of cooling after sintering has been examined. It has been revealed that the main reason of strength degradation is polymorphism of dicalcium silicate Ca2SiO4 (or short designation С2S: β-Ca2SiO4 ® γ-Ca2SiO4. Ways for increasing the  agglomerate  strength by physical and crystal-chemical stabilization of the high temperature modification of C2S have been proposed and tested. Physical stabilization of C2S agglomerate is increased with its structure reinforcement due to thickening of walls between large pores that is achieved by increasing height of the sintered layer through improvement of its gas permeability. The task is addressed by substituting the previously used import sintering ore with the  polydisperse ore from the Yakovlevo field, which improves the charge  pelletizing by 3-4 times and helps to bring the  height of the sintered layer and the strength of the domestic agglomerate up to the international best practice standards, while eliminating a need to purchase import high-vacuum   exhausters. In practice crystal-chemical stabilization of C2S within iron-ore  agglomerate is ensured by adding an  opti- mal multicomponent additive in the form of the    waste product  generated in production  of alumina  from bauxites, i.e. the red mud, to the initial sinter charge. Thus mechanical strength of agglomerates and pellets is increased by 5-10 % and their hot strength improves by 20-40 %. The productivity of sintering machines and blast furnaces improves by 5-10 %. Specific coke consumption reduces by 2-2.5 %. In production of iron-ore pellets red mud is substituting the import  bentonite.

Petrological and geochemical features of the early Paleozoic granitic gneisses and iron ores in the Tianhu iron deposit, Eastern Tianshan, NW China: Implications for ore genesis

Science.gov (United States)

Zheng, Jiahao; Mao, Jingwen; Yang, Fuquan; Chai, Fengmei; Shen, Ping

2017-08-01

This paper reports whole-rock geochemical, zircon U-Pb and Hf isotopic data for ore-hosted granitic gneisses, mineral compositions of oxides, and sulfur isotopic data for sulfides in iron ores from the Tianhu deposit, central part of the Eastern Tianshan. Our results can provide crucial constraints on the genesis of granitic gneisses and early Paleozoic tectonic setting of the Eastern Tianshan. LA-ICP-MS U-Pb dating on magmatic zircons yielded weighted mean 206Pb/238U ages of 463 to 438 Ma, interpreted as the crystallization ages of the granitic protoliths and the formation ages of the Tianhu Group. Zircon U-Pb age of ore-hosted granitic gneiss (ca. 459 Ma) can provide reliable constrains on upper limit for iron mineralization age in the Tianhu deposit. Geochemical characteristics suggest that the protoliths of the Tianhu granitic gneisses are metaluminous to weakly peraluminous high-K calc-alkaline granitic rocks, exhibiting typical subduction-related features such as strong enrichment in LREE and LILE and depletion in HFSE. Zircon Hf isotopic compositions show a positive trend from 463 to 438 Ma, indicating that 460 Ma magmas came from both ancient and juvenile sources, whereas 438 Ma magmas involved more juvenile material. Some early Paleozoic granitoids were recently identified in the Eastern Tianshan with the ages between ca. 475 and ca. 425 Ma. The formation of these early Paleozoic granitoids was in response to subduction processes, suggesting that subduction of Junggar Ocean probably began in the Early Ordovician and lasted until Late Silurian. Pyrite and pyrrhotite in iron ores have δ34SCDT values from + 4.6 to + 15.7‰, which are consistent with the marine source, but inconsistent with the magmatic source or those involved evaporites in skarn iron deposit. Geological, geochemical, and isotopic data suggest that the Tianhu iron ores were formed by volcano-sedimentary processes in a subduction environment during the early Paleozoic time, and Tianhu is a

XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

International Nuclear Information System (INIS)

Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

2015-01-01

Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases

Assessing the impact of iron ore mining to the groundwater in Goa, using stable isotopes

International Nuclear Information System (INIS)

Arzoo Ansari, Md.; Sinha, U.K.; Mohokar, H.V.; Deodhar, Archana; Mendhekar, G.N.; Jaryal, Ajay

2017-01-01

Goa contributes about 50% of the total iron ore exported from the country. Iron ore share is 95% of total mining and quarrying sector in Goa. It represents the second most important industry next to tourism. The iron ore is predominantly mined by opencast mining throughout Goa. The reduction of the forest cover, huge dumps, dust mineral particles, water contamination and health problems are some of the principal harmful effects of extensive mining which is of great concern to the environment. The objective of this study is to assess the impact of iron ore mining to groundwater in downstream side of the mine pits using isotope hydrological techniques

Direct Reduction of Iron Ore

Science.gov (United States)

Small, M.

1981-04-01

In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

Analytical applications of condensed phosphoric acid-I Determination of ferrous and total iron in iron ores after decomposition with condensed phosphoric acid.

Science.gov (United States)

Mizoguchi, T; Ishii, H

1978-06-01

A simple method is described for the determination of ferrous and total iron in iron ores. Iron ores are dissolved by condensed phosphoric acid (CPA) very rapidly without any tedious and time-consuming manipulations such as elimination of silica and filtration. Under the proposed conditions (amount of sample 100 mg, amount of CPA added 10 g, heating temperature 290 degrees , heating time 30 min), magnetite, limonite and hematite are completely dissolved. The iron content can be determined in the presence of condensed phosphoric acid by titration with dichromate solution, if a slight modification is made. The total iron in iron ores, determined by the present method, is in agreement with that found by the JIS method. The ferrous iron in iron ores can be determined by dissolving the samples with CPA in a nitrogen atmosphere and titrating with dichromate solution. Chelatometric titration of iron after solvent extraction with MIBK from solutions prepared by use of CPA is found to be accurate for samples such as pyrite cinder. The ability of CPA to dissolve various materials has been investigated.

XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

Energy Technology Data Exchange (ETDEWEB)

Omran, Mamdouh, E-mail: mamdouh.omran@oulu.fi [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); Fabritius, Timo [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A. [Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); El-Aref, Mortada; Elmanawi, Abd El-Hamid [Geology Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

2015-08-01

Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe{sub 2}O{sub 3} and P{sub 2}O{sub 5} contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe{sup 3+}) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases.

Immobilization of Uranium Silicide in Sintered Iron-Phosphate Glass

International Nuclear Information System (INIS)

Mateos, Patricia; Russo, Diego; Rodriguez, Diego; Heredia, A; Sanfilippo, M.; Sterba, Mario

2003-01-01

This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U 3 O 8 , the amount of U 3 O 8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P 2 O 5 ; 22,7 Fe 2 O 3 ; 8,1 Al 2 O 3 ; 4,3 Na 2 O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m -2 .day -1 ), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

Effect of recycling blast furnace flue dust as pellets on the sintering performance

Directory of Open Access Journals (Sweden)

El-Hussiny N.A.

2010-01-01

Full Text Available The Egyptian Iron and Steel Company generates a great amount of blast furnace flue dust. The recovery of metals and carbon from this flue dust becomes a very important demand due to the increase of the price of coke breeze and the decrease of the primary source of metals. At the same time, it make the environment more safe by decreasing pollution. Introducing these dust fines in the sintering process proves to be very harmful for different operating parameters. Thus, this study aims at investigating the production of pellets resulting from these fines, using molasses as organic binder and its application in sintering of iron ore. The sintering experiments were performed using flue dust as pellets as a substitute of coke breeze. The results revealed that, sintering properties such as inter strength increases with using the flue dust pellets, while productivity of both the sinter machine and sinter machine at blast furnace yard decreases. Also the vertical velocity of the sinter machine and the weight loss during the reduction of produced the sinter by hydrogen decrease.

chemical and mineralogical characterization of lateritic iron ore

African Journals Online (AJOL)

DJFLEX

2010-04-22

Apr 22, 2010 ... The laterite iron ore deposit at Auchi, Edo State, Nigeria was studied chemically and mineralogically. The results of the chemical ... SAMPLE PREPARATION. The samples .... 2µm) and were subjected to X-ray diffraction using.

Analysis of Characteristics of Ore about Iron Deposit of Da Hong Mountain in Yun Nan Province

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Zhang Yuefeng

2016-01-01

Full Text Available This thesis aims to analyse the deposit characteristics about Da Hong Mountains Iron ore in Yunnan province. The texture and structure, especially the chemical composition, is different in every section of deposit after comparing. Moreover, the content of SiO2 is much higher than general iron ore. However, the content of other noble metals cannot reach the lowest industrial grade. Da Hong Mountains Iron ore has unique features because of metallogenic periods.

Geophysical prospecting for iron ore deposit around Tajimi village, Lokoja, North–Central Nigeria

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Bayowa Oyelowo

2016-09-01

Full Text Available Ground magnetic and electrical resistivity survey were undertaken to investigate the occurrence and geometry of iron ore deposit around Tajimi village, Lokoja, North-Central Nigeria. The generated residual map of the ground-magnetic data acquired at 250 stations along 15 traverses revealed numerous prominent anomalies, mostly trending in the N-S direction. The radial power spectrum revealed the depth to magnetic sources between 6 m to 20 m. The interpreted VES data characterized the area into three subsurface layers: top soil, presumably iron ore layer and weathered/fresh basement. The result of vertical electrical sounding curves showed a sudden drop in resistivity (42-241 Ωm over high magnetic response. The geo-electric section revealed that the study area is generally characterized with thin overburden (0.5-1.7 m and the thickness of the second layer (presumed to be the iron ore layer ranged between 6.2-25.1 m. The study concluded that areas of high magnetic intensity showed a sudden drop in resistivity value for the VES points, which give an indication of the presence of an electrically conductive structure presumed to be iron ore deposits.

Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

Energy Technology Data Exchange (ETDEWEB)

Wicakso, Doni Rahmat [Chemical Engineering Department, Faculty of Engineering, Lambung Mangkurat University, Jalan A. Yani KM. 36 Banjarbaru, 70714, South Kalimantan (Indonesia); Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Sutijan; Rochmadi [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Budiman, Arief, E-mail: abudiman@ugm.ac.id [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Center for Energy Studies, Gadjah Mada University, Sekip K1A, Yogyakarta, 55281 (Indonesia)

2016-06-03

Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 – 600 °C and catalyst weight between 0 – 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore pores to from gases, light hydrocarbon (bio-oil) and carbon, thus decreasing content tar in bio-oil and increasing the total gas product. In conclusion, the more low grade iron ore used as catalyst, the tar content in the liquid decrease, the H{sup 2} productivity increased and calorimetric value of bio-oil increased.

Direct Biohydrometallurgical Extraction of Iron from Ore. Final Technical Report

International Nuclear Information System (INIS)

T.C. Eisele

2005-01-01

A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe +2 ) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron

Direct Biohydrometallurgical Extraction of Iron from Ore. Final technical report

International Nuclear Information System (INIS)

T.C. Eisele

2005-01-01

A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe +2 ) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron

Automation of the second iron ore slurry pipeline from Samarco

Energy Technology Data Exchange (ETDEWEB)

Aguilar, Juliana M.; Fonseca, Mario L.; Drumond, Pablo P.; Barbosa, Sylvio [IHM Engenharia, Belo Horizonte, MG (Brazil)

2009-07-01

The second iron ore slurry pipeline from Samarco was build to attend the Third Pellet Plant Project, which includes a new Concentration Plant at Germano-MG and a third Pellet Plant at Ubu-ES. It has 396km of extension and links the two plants by pulping the iron ore slurry prepared at Germano Unit. This works aims to present the iron ore slurry pipeline with emphasis on the automation architecture for the supervision and control system, interconnect throughout the pipe extension by fiber optics. The control system is composed of ControlLogix CLP's at the pulping and valve station and Micrologix CLP's at the pressure and cathodic protection monitoring points, totalizing 19 PLC's. The supervisory system was developed using the Wonderware IAS 3.0 suite, including the supervisory software InTouch 9.5 and the integrated ArchestrA IDE, and is composed of two data servers in redundancy and nine operation stations. The control and supervision system is interconnect through and Ethernet network using fiber optics and multiplexer modules (GE JungleMux) for voice, data and video. Among the expected results, it can be highlighted the sequence automation, greater process data availability (real and historical) and greater facility for the operation and detection of failures. (author)

Geochemistry and the origin of the Mamouniyeh iron ore-terra rossa deposit, Markazi Province - Iran

Directory of Open Access Journals (Sweden)

Marziyeh Mahboubiyan Fard

2017-11-01

Full Text Available Introduction Iron is among the metals whose ore deposits are not confined to a specific geologic period of crustal formation and they have formed in various geologic environments during previous periods (Ghorbani, 2007. About 95% of iron ore deposits have sedimentary origin and have formed due to chemical deposition from ancient sea water. The remaining percent is the result of alteration and magmatic activities (Gutzmer and Beukes, 2009. In sedimentary environments, a large amount of sedimentary iron minerals have formed resulting in different iron facies. Iron oxide facies are of the most important facies (James, 1954. The most important Iranian iron deposits are located in Central Iran, Sanandaj- Sirjan and East Iran zones, and the Kordestan area (Ghorbani, 2007. In the Orumiyeh-Dokhtar Zone, many iron ore deposits have been formed in conjunction with granitic and granodioritic plutons related to Oligocene-Miocene plutonic and volcanic activities (Hoshmandzadeh, 1995. The Mamouniyeh iron ore-terra rossa deposit is located in the Orumiyeh-Dokhtar volcanic zone. Iron mineralization have occurred in trachytic-trachyandesitic lavas and pyroclastic rocks of Pliocene age. Materials and methods A total of 28 rock samples were picked up from ore and host rocks during field observations. Petrographical and mineralogical studies were performed on 15 thin sections of ore and host rocks. XRD studies were performed on 3 ore samples. In order to investigate the geochemistry of the ore, 10 samples were analyzed for major, trace and rare earth elements (REEs using the ICP-MS method. Result Field and mineralogical studies reveal that the ore is composed of hematite along with crypto-crystalline silica as alternating layers of various thickness and color. The existence of alternating layers of hematite and quartz implies that the ore is similar to banded iron formations, but on a smaller scale, related to submarine hydrothermal activities. Silica is found as

Getting rid of the unwanted: highlights of developments and challenges of biobeneficiation of iron ore minerals-a review.

Science.gov (United States)

Adeleke, Rasheed A

2014-12-01

The quest for quality mineral resources has led to the development of many technologies that can be used to refine minerals. Biohydrometallurgy is becoming an increasingly acceptable technology worldwide because it is cheap and environmentally friendly. This technology has been successfully developed for some sulphidic minerals such as gold and copper. In spite of wide acceptability of this technology, there are limitations to its applications especially in the treatment of non-sulphidic minerals such as iron ore minerals. High levels of elements such as potassium (K) and phosphorus (P) in iron ore minerals are known to reduce the quality and price of these minerals. Hydrometallurgical methods that are non-biological involving the use of chemicals are usually used to deal with this problem. However, recent advances in mining technologies favour green technologies, known as biohydrometallurgy, with minimal impact on the environment. This technology can be divided into two, namely bioleaching and biobeneficiation. This review focuses on Biobeneficiation of iron ore minerals. Biobeneficiation of iron ore is very challenging due to the low price and chemical constitution of the ore. There are substantial interests in the exploration of this technology for improving the quality of iron ore minerals. In this review, current developments in the biobeneficiation of iron ore minerals are considered, and potential solutions to challenges faced in the wider adoption of this technology are proposed.

Modeling drying of iron ore pellets

OpenAIRE

Ljung, Anna-Lena

2010-01-01

Iron ore pellets are a highly refined product supplied to the steel making industry for use in blast furnaces or direct reduction processes. The use of pellets offers many advantages such as customer adopted products, transportability and mechanical strength yet the production is time and energy consuming. Being such, there is a natural driving force to enhance the pelletization in order to optimize production and improve quality. The aim with this thesis is to develop numerical models with w...

Borax as flux on sintering of iron Ancor Steel 1000® under glow discharge

Science.gov (United States)

Ariza Suarez, H. G.; Sarmiento Santos, A.; Ortiz Otálora, C. A.

2016-02-01

This work studies the flux effect of borax (di sodium tetraborate decahydrate) on sintering of iron Ancor Steel 1000® in abnormal glow discharge. The incidence of the percentage by weight of borax and the sintering temperature in the process were observed. Samples of powder metallurgical iron were prepared with proportions of 0.50%, 2.0%, 4.0% and 6.0% by weight of borax using the procedures of powder metallurgy. The samples were sintered at 800 and 1100°C for 30min, by glow discharge at low pressure in a reducing atmosphere composed of 20% H2+80% Ar. The samples in compact green-state were analyzed by TGA-DSC to determine the fusion process and mass loss during sintering. The analysis of microhardness and density, shows that at a sintering temperature of 800°C the sample density decreases and the sample microhardness increases with respect to sintered samples without borax. Sintered samples were analysed by DRX showing the absence of precipitates.

Work Index and Grinding Energy Assessment of Dilband Iron Ore, Pakistan

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Muhammad Ishaque Abro

2011-01-01

Full Text Available Importance of comminution in mineral processing sector is highly acknowledged from energy perspective. In present study an attempt was made to understand the comminuting behavior of Dilband iron ore and to compute the grinding energy requirement for production of ultrafine particles up to mesh of liberation. In this regard standard grindability tests developed by the Chair of Mineral Processing Leoben Austria was used for calculating work index of Dilband iron ore. The grinding tests were conducted in rod and ball mills. The work index value of two feed size fractions with 80% passing at 3800?m and 5200?m was noted to be 11.85 kwh/t and 9.3 kwh/ton respectively. Ball mill grinding test indicates that dry grinding in open circuit is not efficient and consumes more energy of 88.48kwh/t of ore for grinding 1000/40?m to 80% <40?m size.

A laboratory study to evaluate the possibility of sulphur and phosphorous removal from iron ore concentrate by leaching

Directory of Open Access Journals (Sweden)

Pour Hassan Rezvani

2016-01-01

Full Text Available Iron ore concentrates with high grade sulfur cause several problems in the steel making process, and hence affect the concentrate price. Environmental issues such as sulfur dioxide emission during the concentrate pelletizing process and effect on the steel quality are other issues. The current study was focused on removal of sulfur from the iron ore concentrate by using the chemical leaching technique. The magnetite iron ore concentrate was chosen for this purpose. The results obtained showed that more than 90% of the total sulfur content was removed from the iron ore concentrate by chemical leaching. Effects of several parameters such as temperature, particle size and use of organic solvent on sulfur removal were investigated by a series of experiments. After optimizing the experimental conditions, it was demonstrated that with addition of sulfur, phosphorus, another important impurity was also removed from the iron ore concentrate. In addition, one of the major advantages of our proposed method was transformation of mineral pyrites to useful by-products such as elemental sulfur.

Possible actions for the minimization of the environmental impact of the iron ore sintering fumes

International Nuclear Information System (INIS)

Garcia-Carcedo, F.; Ayala, N.; Isidro, A.; Moro, A.; Cornejo, N.; Ferreira, S.; Hernandez, A.; Cobo, A.; Alaiz, E.; Garcia, J. R.

2004-01-01

In sintering plants, gaseous emissions are generated which must comply with increasingly demanding environmental regulations. In the sintering process, about 40 kg of coke and 1,700 Nm''3 of air are used per ton of useful sinter. Sintering fumes have a gaseous phase formed mainly of N 2 , O 2 , CO 2 , H 2 O and CO and the minor components SO . SO 3 , NO and NO 2 . Other minor components include unburned organic products and CLH, and minimal proportions of other high impact compounds such as dioxins and furans are also present. Chlorides and heavy metals are present in the solid fraction. This paper reviews the situation of each emission in relation with the applicable regulations, and the possible means of reducing these emissions. (Author) 12 refs

The separation and determination of trace elements in iron ore

International Nuclear Information System (INIS)

Jones, E.A.

1977-01-01

The separation, concentration, and determination of trace elements in iron ores are described. After the sample has been dissolved, the iron is separated by liquid-liquid extraction with a liquid cation-exchanger, di-(2-ethylhexyl) phosphoric acid. The trace elements aluminium, cadmium, calcium, chromium, cobalt, copper, lead, magnesium, manganese, mercury, potassium, sodium, vanadium, and zinc are determined in the aqueous phase by atomic-absorption spectrophotometry

On-line and bulk analysis of iron ore and bauxite

International Nuclear Information System (INIS)

Holmes, R.J.; Roczniok, A.F.

1983-01-01

A number of analysis techniques based on neutron and gamma radiation have been developed for the mining industry. Current projects include the measurement of annihilation radiation arising from pair production for the on-line determination of the iron content of iron ores, and the construction of a demonstration bauxite analyser based on fast-neutron activation analysis for the simultaneous determination of aluminium and silicon content

Vanadium-bearing titaniferous iron ores from the Rooiwater, Usushwana, Mambula, Kaffirskraal, and the Trompsburg igneous complexes

International Nuclear Information System (INIS)

Reynolds, A.M.

1979-01-01

The mineralogy and chemistry of some vanadium-bearing titaniferous iron ores from a number of smaller South African basic intrusions are reported, and an assessment is given of the potential of these ores for use as raw materials in the production of iron, high-titania slag, and vanadium pentoxide. The ores from each complex can be distinguised readily on the basis of their chemical composition and textural relations. The Rooiwater Complex represents the most promising area. It contains two layers of titaniferous magnetite, each approximately 8 m thick, in the eastern part, the lowest seam being chemically similar to the economically important main layer of titaniferous magnetite in the Bushveld Complex. The ores are silicate-poor and consist largely of multi-phase titaniferous-magnetite grains containing modified ilmenite and pleonaste micro-intergrowths. The coarse grain size of these ores favours beneficiation, and they can be partially treated to yield ilmenite concentrates and low-titania magnetite fractions in which the content of vanadium pentoxide is higher than that in the original ores. The Mambula ores are silicate-rich and would require extensive beneficiation. The Kaffirskraal ores consist of multi-phase grains of titaniferous magnetite containing crystallographically oriented ilmenite, ulvospinel, and pleonaste micro-intergrowths. Minor coarser-grained ilmenite is also present. The Usushwana ores are texturaly similar but contain abundant lamellar ilmenite in place of the ulvospinel. The ores from these two complexes cannot be beneficiated by conventional ore-dressing techniques, and would require direct metallurgical treatment for the recovery of iron, titania, and vanadium pentoxide [af

Growth characteristics of a strain of iron-oxidizing bacterium and its application in bioleaching of uranium ores

International Nuclear Information System (INIS)

Zhang Rui; Liu Yajie; Gao Feng; Xu Lingling

2008-01-01

05B is a strain of iron-oxidizing bacterium which separated from a uranium ore. The effect of temperature, initial pH, inoculation amount and initial total iron concentration on the strain's growth and activities in bioleaching of uranium ores are studied. The results show that the optimum growth temperature is 40-45 degree C, the optimum inoculation pH value being 1.5-1.7, the optimum initial inoculation amount being 10%-20%, and the initial total iron concentration being not more than 5 g/L. 05B is fit for leaching of low grade uranium ores. (authors)

Application of natural gas to the direct reduction of iron ore

Energy Technology Data Exchange (ETDEWEB)

1975-05-01

The Gas Committee of the U.N. Economic Commission for Europe evaluated the potentials of natural gas for direct reduction of iron ore. The report, based essentially on that by the Italian representative E. Pasero with comments and observations from experts of the other member countries, indicated the general tendency of the iron and steel industry to use natural gas to reduce production costs by reducing coke consumption. By the end of 1972, gas consumption by these industries was reported at 38.8 billion Btu/ton (10.79 Gcal/m ton) by the Steel Committee of the U.N. Economic Commission at the symposium on the economic and technical aspects of the direct reduction of iron ore, held in September 1972 in Bucharest. In comparison, coke consumption was 9.5 billion Btu/ton (2.64 Gcal/m ton) steel, liquid hydrocarbons 3.1 billion Btu (0.85 Gcal), and electricity 16.1 billion Btu (4.46 Gcal). Natural gas was used mainly for ore reduction and generation of the reducing gas in-shaft furnaces with backdraft heating circulation, fixed-bed furances (Hyl type), and fluidized-bed reactors. Processes include the Midrex (shaft furnace), H.I.B. (fluidized bed), and Novalfer (fluidized bed). These processes are used to obtain 4.5 million tons/yr of iron sponge for the production of steel in electric furnaces. The natural gas outlook for direct reduction of iron will depend on local conditions and fuel availability. Its industrial application has been most successful in mini-steel installations, especially in the U.S., Japan, and Western Europe, and it is recommended for developing countries with no steel-industry basis.

X-ray fluorescence diffractionless analyzer for determining light element content in iron ore mixtures

International Nuclear Information System (INIS)

Yuksa, L.K.; Kochmola, N.M.; Bondarenko, V.P.; Bogdanov, V.K.

1986-01-01

Diffractionless X-ray fluorescence analyzer for detecting calcium oxide and silicon dioxide contents in dry iron ore materials has been developed. The analyzer includes a charging unit, sample-conveying device, spectrometric units for detecting calcium and silicon, computing racks and sample-removing device. Results of calcium oxide and silicon dioxide analyses in iron ore mixtures are presented. Errors are evaluated. It is shown that the analyzer provides high accuracy of one-time determinations, as well as reading constancy for a long time

Monitoring Sintering Burn-Through Point Using Infrared Thermography

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Francisco G. Bulnes

2013-08-01

Full Text Available Sintering is a complex industrial process that applies heat to fine particles of iron ore and other materials to produce sinter, a solidified porous material used in blast furnaces. The sintering process needs to be carefully adjusted, so that the combustion zone reaches the bottom of the material just before the discharge end. This is known as the burnthrough point. Many different parameters need to be finely tuned, including the speed and the quantities of the materials mixed. However, in order to achieve good results, sintering control requires precise feedback to adjust these parameters. This work presents a sensor to monitor the sintering burn-through point based on infrared thermography. The proposed procedure is based on the acquisition of infrared images at the end of the sintering process. At this position, infrared images contain the cross-section temperatures of the mixture. The objective of this work is to process this information to extract relevant features about the sintering process. The proposed procedure is based on four steps: key frame detection, region of interest detection, segmentation and feature extraction. The results indicate that the proposed procedure is very robust and reliable, providing features that can be used effectively to control the sintering process.

Dynamic trial of an on-stream analyser for iron ore fines

International Nuclear Information System (INIS)

Holmes, R.J.; Miles, J.G.

1980-01-01

A thermal neutron irradiation technique using a 252 Cf neutron source has been developed and applied to the simultaneous determination of iron and aluminium (expressed as Al 2 O 3 ) in iron ore fines (-6 mm particle size) on a moving rubber conveyor belt. While the determination of iron with this technique is based on the use of a NaI(Tl) detector to monitor the characeristic prompt gamma rays (7.64 MeV) emitted by thermal neutron capture reactions in the iron, the determination of Al 2 O 3 is based on the use of a second NaI(Tl) detector to monitor the characteristic gamma rays (1.78 MeV) emitted after thermal neutron activation of the aluminium. The second detector is located downstream from the first. Although the speed of the conveyor belt has no direct effect on the iron measurements, it must not exceed about 3 m/min if good accuracy is required for the Al 2 O 3 measurements. Consequently an auxiliary conveyor belt is required in order to avoid interference with normal ore processing. Dynamic trials of the technique have demonstrated that the method can achieve accuracies of 0.7% Fe and 0.1% Al 2 O 3

Iron ore catalysts for methane decomposition to make CO x free hydrogen and carbon nano material

KAUST Repository

Zhou, Lu; Enakonda, Linga Reddy; Li, Sheng; Gary, Daniel; Del-Gallo, Pascal; Mennemann, Christina; Basset, Jean-Marie

2018-01-01

In this work, for the first time, iron ores with 91.7%–96.2% FeO, 1.3%–2.3% AlO, 1.2%–4.5% SiO, 1.3%–3.9% NaO, were studied directly as bulk catalysts for methane decomposition. By hydrogen pre-reduction at 850 °C, FeO species on iron ores were

Overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil

Energy Technology Data Exchange (ETDEWEB)

Silva, Adarlan M.; Passos, Aline C.; Santos, Daniel; Orban, Eduardo M.; Lisboa, Helder D.; Goncalves, Nilton; Guimaraes, Robson C. [Anglo Ferrous Brazil, Rio de Janeiro, RJ (Brazil)

2009-07-01

The objective of this paper is to present an overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil. Anglo Ferrous Brazil is a company of Anglo American plc that is one of the world's largest mining and natural resource company. Minas-Rio is a world class iron ore project which has been developed in Brazil aiming to produce 26.6 million tons per year of concentrate. The mine, concentrator and pump station 1 will be located in Conceicao do Mato Dentro, Minas Gerais state, and the terminal station will be located at Acu Port in Sao Joao da Barra, Rio de Janeiro state. The long distance iron ore slurry pipeline will be one of major differentials of Minas-Rio Project and its useful life was initially estimated in 20 years. The slurry pipeline has a total length of 525 kilometers and will be constructed from predominately 26 inches external diameter API 5L X70 pipes. From kilometer 314 to kilometer 480, 24 inches pipe will be installed to prevent slack flow downstream pump station 2. The pump station 1 is designed to provide the hydraulic head necessary to transport the concentrate iron ore slurry with 8 positive displacement pumps to pump station 2. The pump station 2, located 240 kilometers downstream pump station 1, is designed to operate with 10 positive displacement pumps. The valve station will be located at kilometer 347 and will be used to break the static head between pump station 2 and the terminal station during a slurry pipeline shutdown. (author)

Production of lightweight ceramisite from iron ore tailings and its performance investigation in a biological aerated filter (BAF) reactor

International Nuclear Information System (INIS)

Liu Yangsheng; Du Fang; Yuan Li; Zeng Hui; Kong Sifang

2010-01-01

The few reuse and large stockpile of iron ore tailings (IOT) led to a series of social and environmental problems. This study investigated the possibility of using the IOT as one of starting materials to prepare lightweight ceramisite (LWC) by a high temperature sintering process. Coal fly ash (CFA) and municipal sewage sludge (SS) were introduced as additives. The LWC was used to serve as a biomedium in a biological aerated filter (BAF) reactor for municipal wastewater treatment, and its purification performance was examined. The effects of sintering parameters on physical properties of the LWC, and leaching concentrations of heavy metals from the LWC were also determined. The microstructure and the phase composition of the LWC were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results revealed that: (1) IOT could be used to produce the LWC under the optimal sintering parameters; (2) the leaching concentrations of heavy metals from the LWC were well below their respective regulatory levels in the China Environmental Quality Standards for Surface Water (CEQS); and (3) the BAF reactor with the LWC serving as the biomedium achieved high removal efficiencies for COD Cr (>92%), NH 4 + -N (>62%) and total phosphate (T-P) (>63%). Therefore, the LWC produced from the IOT was suitable to serve as the biomedium in the municipal wastewater treatment.

On-line iron ore slurry monitoring using laser induced plasma spectroscopy

International Nuclear Information System (INIS)

Barrette, L.; Turmel, S.; Boivin, J.-A.; Sabsabi, M.; Martinovic, T.I.; Ouellet, G.

1999-01-01

In response to the need for a better control [Lb1] of the various additives used in the iron ore pellet making process, Laser-Induced Plasma Spectroscopy (LIPS) has been tested for the on-line monitoring of Si, AI, Ca, Mg, and C. This work shows that factors such as laser beam focusing, particle size, slurry density and mineralogical composition have to be taken into account to meet precision and accuracy requirements. An internal standardization (peak ratio) and an original multivariate calibration technique based on fuzzy logic concepts [Lb2] are [Lb3] used to minimize the effect of these factors. This paper describes the experimental set-up, the effect of influence factors and the results obtained both in the laboratory and in an iron ore plant. (author)

Investigating the Utility of Iron Ore Waste in Preparing Non-fired Bricks

Science.gov (United States)

Lamani, Shreekant R.; Mangalpady, Aruna; Vardhan, Harsha

2017-10-01

Iron ore waste is a major problem for mine owners due to the difficulty involved in its storage, handling and other environmental related issues. An alternative solution to this is utilisation of iron ore waste (IOW) as some value added product in construction industry. An attempt has been made in this paper in examining the possibility of making non-fired bricks from iron ore waste with some additives like cement and fly-ash. Each of the additives were mixed with IOW in different ratios and different sets of bricks were prepared. The prepared IOW bricks were cured for 7, 14, 21 and 28 days and their respective compressive strength and percentage of water absorption were determined. The results show that IOW bricks prepared with 9% and above cement and with 28 days of curing are suitable for brick making and meet the IS specifications. It was also observed that the weight of the prepared bricks with 9% cement with 28 days of curing varies between 2.35 and 2.45 kg whereas the weight of compressed fire clay bricks varies from 2.80 to 2.89 kg. Results also show that the cost of bricks prepared with cement ranging from 9 to 20% is comparable to that of commercially available compressed bricks.

Phytostabilisation potential of lemon grass (Cymbopogon flexuosus (Nees ex Stend) Wats) on iron ore tailings.

Science.gov (United States)

Mohanty, M; Dhal, N K; Patra, P; Das, B; Reddy, P S R

2012-01-01

The present pot culture study was carried out for the potential phytostabilisation of iron ore tailings using lemon grass (Cymbopogon flexuosus) a drought tolerant, perennial, aromatic grass. Experiments have been conducted by varying the composition of garden soil (control) with iron ore tailings. The various parameters, viz. growth of plants, number of tillers, biomass and oil content of lemon grass are evaluated. The studies have indicated that growth parameters of lemon grass in 1:1 composition of garden soil and iron ore tailings are significantly more (-5% increase) compared to plants grown in control soil. However, the oil content of lemon grass in both the cases more or less remained same. The results also infer that at higher proportion of tailings the yield of biomass decreases. The studies indicate that lemongrass with its fibrous root system is proved to be an efficient soil binder by preventing soil erosion.

Influence of surface topography on the surface durability of steam oxidised sintered iron

Directory of Open Access Journals (Sweden)

José Daniel Biasoli de Mello

2005-06-01

Full Text Available Durability of surfaces has been reported as the main factor affecting tribological behavior of steam oxidised sintered iron. The presence of surface pores and their negative influence on load bearing capacity, suggest that surface topography might play an important role on the durability of the oxide layer. In this paper, the influence of compaction pressure and powder grade on surface topography, and as a consequence, its effect on the tribological behavior of steam oxidised sintered iron has been analysed. Specimens prepared from atomised iron powders with different sizes were compacted using 4 different pressures, sintered, and then subjected to steam treatment. Tribological characterisation was carried out in a reciprocating sliding wear test. Although the processing parameters affected the surface topography to a considerable extent, the main influence may be attributed to powder grade. A strong influence of surface topography on the durability distance, evaluated in terms of the evolution of contact resistance with total sliding distance, has been highlighted. Surfaces which were smoother and had high load-carrying capacity were always associated with a higher durability distance.

Influence of particle size and mineral phase in the analysis of iron ore slurries by Laser-Induced Breakdown Spectroscopy

International Nuclear Information System (INIS)

Michaud, Daniel; Leclerc, Remi; Proulx, Eric

2007-01-01

Laser-Induced Breakdown Spectroscopy (LIBS) was applied to the analysis of iron ore concentrates. The objective was to determine the influence of particle size and mineral phase on the LIBS signal. The LIBS spectra of hematite and magnetite ore concentrates were qualitatively indistinguishable from each other but magnetite yielded systematically less than hematite. This behavior could be set into an empirical equation to correct the iron peak intensities according to the level of magnetite in the analyzed sample. Similarly, an increase of the LIBS signal was observed as the particle size of the ore samples decreased. Again, an equation could be written down to correct the intensity of either iron or silicon in response to a variation of the average particle size of the ore concentrate. Using these corrections, proper response of the silicon signal against the concentration of silica in the samples was restored. The observed dependence of the strength of the iron signal upon the mineral phase is attributed to oxidation of magnetite into hematite

Fuzzy control of the iron ore pellets thermal treatment on a conveying car

Directory of Open Access Journals (Sweden)

В’ячеслав Йосипович Лобов

2017-07-01

Full Text Available The purpose of this article is to solve the problem of fuzzy control of iron ore pellets thermal treatment on a conveyor roasting machine, to build an automated control system of conveyor roasting machine and perform simulation and to present the results of research. According to the structural scheme of the fuzzy control an automated control system is proposed for being modelled. This is done by using the software MATLAB. The use of atomic emission spectroscopy determines the percentage of the major elements in iron ore pellets considering the main process parameters. This article uses an automated system of fuzzy control of iron ore pellets firing on a conveyor roasting machine with the introduction of atomic emission spectroscopy of the pellets. Development and practical implementation of fuzzy control will improve their quality by taking into account the basic parameters of thermal treatment of pellets such as speed of movement of the grate trucks, gas flow rate, the height of the layer of pellets and the venting speed of the pellets layer with gas-air flow, humidity, average diameter, the basicity and the iron composition in the pellets. The expediency of the developed method of using automated fuzzy control system of iron ore pellets firing on a conveyor roasting car has been proved. The system with fuzzy controller provides a reduction on average 2 m3/h, which is 0,3% of natural gas consumption as compared to the existing systems. This provides more uniform gas permeability of the layer of pellets, which leads to filtration rate increase of the gas flow and to heat exchange intensification in the layer of pellets. It makes it possible to introduce the atomic emission spectroscopy of non-burned pellets and to increase the productivity of conveyor roasting machine by 2,5%. At the same time the resistance of technological equipment (pallets increases, due to more uniform distribution of the thermal field

On-stream analysis of iron ore and its potential for improving export quality control

International Nuclear Information System (INIS)

Holmes, R.J.

1988-01-01

An on-stream iron ore analyser has been developed in collaboration with Hamersley Iron Pty. Limited for determining the iron content of both lump (-30+6 mm particle size) and fines (-6 mm particle size) on conveyor belts. The analyser, which is called IRONSCAN, is based on pair production, and is now commercially available from Mineral Control Instrumentation Limited (MCI) in Adelaide. It can be mounted under existing conveyor belts with minimal modifications to the conveyor structure, and the presence of steel cables in the belt does not interfere once the analyser has been correctly calibrated. The analyser has been extensively tested on both lump and fines on the shiploading conveyor at Dampier, and typically the root mean square (r.m.s.) deviation between single IRONSCAN measurements and conventional chemical analyses is better than 0.5% Fe. It is currently being evaluated on - 150 mm ore from the primary crusher at Mount Tom Price, and initial results are encouraging. The principal advantage of IRONSCAN is that it provides rapid information on ore grades. But perhaps its greatest potential is at the primary crusher where conventional sampling and analysis is very expensive to implement. 11 figs., 1 tab

Did the Kiruna iron ores form as a result of a metasomatic or igneous process? New U-Pb and Nd data for the iron oxide apatite ores and their host rocks in the Norrbotten region of northern Sweden

Science.gov (United States)

Westhues, A.; Hanchar, J. M.; Whitehouse, M. J.; Fisher, C. M.

2012-12-01

A number of iron deposits near Kiruna in the Norrbotten region of northern Sweden are of the iron oxide apatite (IOA) type of deposits; also referred to as Kiruna-type deposits. They are commonly considered a subgroup or end-member of iron oxide copper gold (IOCG) deposits, containing no economic grades of copper or gold. Both IOCG and IOA deposits are characterized by abundant low-Ti Fe oxides, an enrichment in REE, and intense sodium and potassium wall-rock alteration adjacent to the ores. Deposits of these types are of a great economic importance, not only for iron, but also for other elements such as rare earth elements (REE) or uranium. Kiruna, the type locality of the IOA type of mineral deposits, is the focus of this study. Despite a century-long mining history and 2500 Mt of iron ore produced in the region to date (with grades of 30 to 70 wt.% Fe), the genesis of these deposits is poorly understood: theories of a magmatic vs. a hydrothermal or metasomatic origin have been debated, and the timing of mineralization of the ores in the Norbotten region has never been directly dated. The results anticipated from this study will provide a better understanding of the nature of the IOA type of mineral deposits and their relation to IOCG deposits such as Olympic Dam in Australia. An array of geochemical methods is used in order to gain insights on the emplacement history of the host rocks, their subsequent alteration, and the ore genesis of these deposits. This includes in situ U/Pb geochronology of zircon, monazite, and titanite to constrain the timing between host rock emplacement, alteration and mineralization. Isotopic data from whole rocks and in situ at mineral scale will provide constraints on the involvement of hydrothermal fluids and their possible sources, as well as on the sources of Fe, U, and the REE. Newly obtained Sm-Nd isotopic data points to distinct source differences between host rocks, ore and alteration related samples. Preliminary in situ U

Effect of Microstructure on the Thermal Properties of Sintered Iron-copper Composites

OpenAIRE

Ugarteche, Caroline Velasques; Furlan, Kaline Pagnan; Pereira, Rafaela do Vale; Trindade, Gabriel; Binder, Roberto; Binder, Cristiano; Klein, Aloisio Nelmo

2015-01-01

Copper is a well know material for use as heat sink or heat exchanger. However, copper has a considerable low tensile strength and temperature limit. A material that has a good thermal conductivity, low cost, but also resistance is the desired. Effects of copper on the sintering and thermal properties of iron-copper composites produced by powder metallurgy and Fe on copper-iron composites have been investigated. Copper and iron were varied from 20 to 80 vol.% in the samples, alternating the c...

Work stressors, job insecurity, union support, job satisfaction and safety outcomes within the iron ore mining environment

OpenAIRE

Nicolaas W.H. Smit; Leon T. de Beer; Jaco Pienaar

2016-01-01

Orientation: The study of work stressors, job insecurity and union support creates opportunity for iron ore mining organisations to manage job satisfaction and safety motivation and behaviour more effectively. Research purpose: The objective of this study was to investigate the relationship between work stressors, job insecurity, union support, job satisfaction and safety motivation and behaviour of a sample of iron ore mine workers in South Africa. Motivation for the study: The minin...

Experimental Research on the Determination of the Coefficient of Sliding Wear under Iron Ore Handling Conditions

Directory of Open Access Journals (Sweden)

G. Chen

2017-09-01

Full Text Available The handling of iron ore bulk solids maintains an increasing trend due to economic development. Because iron ore particles have hard composites and irregular shapes, the bulk solids handling equipment surface can suffer from severe sliding wear. Prediction of equipment surface wear volume is beneficial to the efficient maintenance of worn areas. Archard’s equation provides a theoretical solution to predict wear volume. To use Archard’s equation, the coefficient of sliding wear must be determined. To our best knowledge, the coefficient of sliding wear for iron ore handling conditions has not yet been determined. In this research, using a pin-on-disk tribometer, the coefficients of sliding wear for both Sishen particles and mild steel are determined with regard to iron ore handling conditions. Both naturally irregular and spherical shapes of particles are used to estimate average values of wear rate. Moreover, the hardness and inner structures of Sishen particles are examined, which adds the evidence of the interpretation of wear results. It is concluded that the coefficients of sliding wear can vary largely for both Sishen particle and mild steel. The wear rate decreases from transient- to steady-state. The average coefficient of sliding wear is capable of predicting wear with respect to long distances at the steady-state. Two types of sliding friction are distinguished. In addition, it is found that the temperature rise of the friction pairs has negligible influence on wear rate.

The effect of iron-ore particles on the metal content of the brown alga Padina gymnospora (Espirito Santo Bay, Brazil)

International Nuclear Information System (INIS)

Nassar, C.A.G.; Salgado, L.T.; Yoneshigue-Valentin, Y.; Amado Filho, G.M.

2003-01-01

Iron ore deposits mat be the source of metals found in the brown alga Padina gymnospora. - The iron-ore particles discharged by a pellet processing plant (Espirito Santo Bay, Brazil) cover the seabed of Camburi Beach and consequently, the epibenthic community. In order to determine the importance of the contribution of the iron-ore deposits to the metal concentration in macroalgae of Espirito Santo Bay, four methods of cleaning particulate material adhered to the surface of thalli were tested prior to metal tissue analysis (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of Padina gymnospora. In addition, heavy metal concentrations were determined in individuals of P. gymnospora from a site (Frade Island) not affected by the iron-ore particles. The most efficient cleaning treatment, a combination of scraping and washing with an ethanol-seawater solution (NA+SC+ET) removed a number of particles on the surface of thalli 10 times higher than that observed in the control (C). Using this treatment, the total-metal concentrations were reduced by 78% for Fe and 50% for Al respect to the control. However, Fe, Al and Cu concentrations after treatment NA+SC+ET were significantly higher than those found at Frade Island. It is suggested that the iron-ore deposit might be a source for metal availability to macroalgae exposed to the dumped material at Espirito Santo Bay

Valorization of mining waste from Ouenza iron ore mine (eastern Algeria

Directory of Open Access Journals (Sweden)

Abdelaziz Idres

Full Text Available Abstract The present article is devoted to the development of a hematite-poor ore mine in Ouenza, which does not meet the steelmaker's requirements. Significant volumes are stored at the pithead of the mine, and the reserves are estimated at over 100 million tones. This enormous quantity of mining waste occupies an important space and poses a real threat to the environment as well as for the mining city of Ouenza. In order to solve these socio-economic and environmental problems, a sustainable development and a better quality of life for inhabitants of this region is needed. For this, representative samples were taken at the level of the dumps. Taking into account the natural characteristics of the stock namely; mineralogical composition, iron content, particle size of the rock mass, as well as the release mesh of iron minerals from the gangue. Firstly, tests are conducted on the recovery by radiometric separation of iron-rich pieces and graded. Then the rest of the ore was subjected to mechanical preparation followed by enrichment, which will be the subject of another study. The research is conducted on samples to determine the optimal parameters of the g-rays absorption tested by radiometry; these parameters were the velocity of the conveyor belt and the time of exposure to g-rays. The obtained results by this valorization process are very significant: iron content 53.5% and 8.3% recovery.

Iron ore catalysts for methane decomposition to make CO x free hydrogen and carbon nano material

KAUST Repository

Zhou, Lu

2018-03-27

In this work, for the first time, iron ores with 91.7%–96.2% FeO, 1.3%–2.3% AlO, 1.2%–4.5% SiO, 1.3%–3.9% NaO, were studied directly as bulk catalysts for methane decomposition. By hydrogen pre-reduction at 850 °C, FeO species on iron ores were gradually reduced into FeO, FeO and then finally into Fe species. After reduction of 1.6 g of iron ore catalysts of 50 µm particle size with 100 mL/min pure H for 3.5 h at 850 °C, CMD life testing was conducted at 850 °C and GHSV of 3.75 L/g h and the catalyst showed a stable methane conversion for 5 h. When methane decomposition proceeded on Fe sites, FeC species would be formed to deposit graphite around themselves to finally form carbon nano onions. This carbon nano onions material showed excellent application for wastewater purification. All samples were fully characterized with XRF, XRD, H-TPR, TEM and Raman.

Elemental analysis of two Egyptian iron ores and produced industrial iron samples by neutron activation analysis

International Nuclear Information System (INIS)

Sroor, A.; Abdel-Basset, N.; Abdel-Haleem, A.S.; Hassan, A.M.

2001-01-01

Elemental analysis of two iron ores and initial industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were performed by the instrumental neutron activation analysis technique. Five samples of each type were irradiated for 48 h in a thermal neutron flux of 4x10 12 n/cm 2 s in the first Egyptian research reactor ET-RR-1. Also, the Pneumatic Irradiation Rabbit System (PIRS), attached to the reactor ET-RR-1 in Inshass, was used to measure short-life elements. The γ-ray spectra were obtained with a hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. Implications of the elemental concentration values obtained are presented

Feasibility Studies for Production of Pellet Grade Concentrate from Sub Grade Iron Ore Using Multi Gravity Separator

Science.gov (United States)

Rao, Gottumukkala Venkateswara; Markandeya, R.; Kumar, Rajan

2018-04-01

An attempt has been made to utilise Sub Grade Iron Ore by producing pellet grade concentrate from Deposit 5, Bacheli Complex, Bailadila, Chhattisgarh, India. The `as received' Run of Mine (ROM) sample assayed 40.80% Fe, 40.90% SiO2. Mineralogical studies indicated that the main ore mineral is Hematite and lone gangue mineral is Quartz. Mineral liberation studies indicated that, the ore mineral Hematite and gangue mineral Quartz are getting liberated below 100 microns. The stage crushed and ground sample was subjected to concentration by using a Multi Gravity Separator (MGS). Rougher Multi Gravity Separation (MGS) experimental results were optimised to recover highest possible iron values. A concentrate of 55.80% Fe with a yield of 61.73% by weight with a recovery of 84.42% Iron values was obtained in rougher MGS concentrate. Further experiments were carried out with rougher MGS concentrate to produce a concentrate suitable for commercial grade pellet concentrate. It was proved that a concentrate assaying 66.67% Fe, 3.12% SiO2 with an yield of 45.08% by weight and with a recovery of 73.67% iron values in the concentrate.

Production of High-purity Magnetite Nanoparticles from a Low-grade Iron Ore via Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Suh, Yong Jae; Kil, Dae Sup; Jang, Hee Dong [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Do, Thi May [Korea University of Science and Technology, Daejeon (Korea, Republic of); Cho, Kuk [Pusan National University, Busan (Korea, Republic of)

2015-02-15

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity Fe{sup 3+} solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of Mg{sup 2+} and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-ore-wastewater treatments, as well as in the economic production of the nano-adsorbent.

Determination of total iron in iron ore by x-ray fluorescence analysis using the Compton effect: comparison with others analytical techniques

International Nuclear Information System (INIS)

Castilho, M.V. de; Oliveira, R.C.

1991-01-01

Total iron in iron ores is determines by X-ray fluorescence analysis method using the compton effect. The Bragg angle is determined for compton no-coherent scattering related to K alpha of Rhodium. This measurement procedure can be used for best fitting of analytical results in X-ray fluorescence, when compared with others methods used for results corrections. (M.V.M.)

Is outdoor work associated with elevated rates of cerebrovascular disease mortality? : a cohort study based on iron-ore mining

OpenAIRE

Björ, Ove; Jonsson, Håkan; Damber, Lena; Burström, Lage; Nilsson, Tohr

2016-01-01

BACKGROUND: A cohort study that examined iron ore mining found negative associations between cumulative working time employed underground and several outcomes, including mortality of cerebrovascular diseases. In this cohort study, and using the same group of miners, we examined whether work in an outdoor environment could explain elevated cerebrovascular disease rates. METHODS: This study was based on a Swedish iron ore mining cohort consisting of 13,000 workers. Poisson regression models wer...

Occurrence of uranium in the itabiritic iron ore of Morro Agudo on the NE border of the iron Quadrangle/Minas Gerais, Brasilien

International Nuclear Information System (INIS)

Guba, I.

1982-01-01

The precambrian itabirites and hematite ores of the Morro Agudo iron ore mine on the NE border of the Quadrilatero Ferrifero in Minas Gerais/Brazil contain uranium-bearing minerals and rare-earth elements. In association with phosphates they occupy planes of joints, fractures and cleavage in the area of amphibolitic schist which is intercalated in the s 1 -planes of the itabirites and hematite ores. Preliminary analyses of the uranium-bearing minerals were made by energy dispersive X-ray spectrometry and electron microscopy. The results are presented in connection with the lithologic and tectonic features of the Morro Agudo mine. (orig.) [de

High-grade iron ore at Windarling, Yilgarn Craton: a product of syn-orogenic deformation, hypogene hydrothermal alteration and supergene modification in an Archean BIF-basalt lithostratigraphy

Science.gov (United States)

Angerer, Thomas; Hagemann, Steffen G.; Danyushevsky, Leonid

2013-08-01

Banded iron formation (BIF)-hosted iron ore deposits in the Windarling Range are located in the lower greenstone succession of the Marda-Diemals greenstone belt, Southern Cross domain, Yilgarn Craton and constitute a total hematite-martite-goethite ore resource of minimum 52 Mt at 60 wt.% Fe (0.07 P). Banded iron formation is interlayered with high-Mg basalts at Windarling and precipitated during episodes of volcanic quiescence. Trace element content and the rare earth element (REE) ratios Y/Ho (42 to 45), Sm/Yb (1.5), together with positive La and Gd anomalies in `least-altered' hematite-magnetite-metachert-BIF indicate the precipitation from Archean seawater that was fertilised by hydrothermal vent fluids with a basaltic HREE-Y signature. Hypogene iron ore in sub-greenschist facies metamorphosed BIF formed during three distinct stages: ore stage 1 was a syn- to post-metamorphic, syn-D1, Fe-Ca-Mg-Ni-Co-P-REE metasomatism that produced local Ni-REE-rich Fe-dolomite-magnetite alteration in BIF. Hydrothermal alteration was induced by hot fluid flow controlled by brittle-ductile reactivation of BIF-basalt margins and crosscutting D1 faults. The Ni-Co-rich content of dolomite and a shift in REE ratios in carbonate-altered BIF towards Archean mafic rock signature (Y/Ho to 31 to 40, Sm/Yb to 1 to 2 and Gd/Gd* to 1.2 to 1.4) suggest that high-Mg basalts in the Windarling Range were the primary source of introduced metals. During ore stage 2, a syn-deformational and likely acidic and oxidised fluid flow along BIF-basalt margins and within D1 faults leached carbonate and precipitated lepidoblastic and anhedral/granoblastic hematite. High-grade magnetite-hematite ore is formed during this stage. Ore stage 3 hydrothermal specular hematite (spcH)-Fe-dolomite-quartz alteration was controlled by a late-orogenic, brittle, compressional/transpressional stage (D4; the regional-scale shear-zone-related D3 is not preserved in Windarling). This minor event remobilised iron oxides

Treatment and Recycling of the Process Water in Iron Ore Flotation of Yuanjiacun Iron Mine

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Wen-li Jiang

2017-01-01

Full Text Available Coagulating sedimentation and oxidation treatment of process water in iron ore flotation of Yuanjiacun iron mine had been studied. The process water of this mine carried residual polyacrylamide (PAM, poly(diallyldimethylammonium chloride (PDADMAC, and Ca2+ from the flotation and caused decrease of the iron flotation recovery or grade of the concentrate. The studies on high-intensity magnetic separation (HIMS tailings for coagulating sedimentation showed that the settling performance of coagulant (named CYH was better than that of PDADMAC. The analyses of FTIR spectra and zeta potential demonstrated that CYH is adsorbed mainly through electrostatic attraction onto HIMS tailings. Sodium hypochlorite was adopted to oxidize the residual organics in tailings wastewater. When sodium hypochlorite is at the dosage of 1.0 g/L, reaction temperature is of 20°C, and reaction time is of 30 minutes, the removal rates of PAM, COD, and Ca2+ were 90.48%, 83.97%, and 85.00%, respectively. Bench-scale flotation studies on the treated tailings wastewater indicated that the iron recovery and grade of concentrate were close to those of freshwater.

Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines

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Alok Sarkar

2013-10-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE The present study deals with the utilization of fines generated from comminution process (crushing, grinding and screening of the Run of Mines into value added products i.e. fluxed iron ore pellets. The study comprises to understand the physical and mechanical behavior of five distinguished chemical compositions of green and dried iron ore pellets with respect to a typical Mini Blast furnace (MBF burden data and furnace operating parameter. The maximum basicity of pellets was calculated 2.37 to make slag neutral when blast furnace runs at 100% high ash coke (avg. ash content= 29%. The crushing strength and drop number of various green pellets were measured. Green Crushing Strength was decreased with increasing lime fines. The addition of lime fines as a burnt lime, which has acicular structure creates less plasticity and brittle like fracture occurred. Due to formation of hard CaCO3 layer on the surface, after increasing lime contain crushing strength was increased in the air and oven dry pellets with respect to acid pellet (0% lime fines addition. [How to cite this article: Sarkar, A., Mandal, A.K., and Sinha, O.P. (2013 Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines. International Journal of Science and Engineering, 5(2,9-14. Doi: 10.12777/ijse.5.2.9-14] 

[Characteristic of Mercury Emissions and Mass Balance of the Typical Iron and Steel Industry].

Science.gov (United States)

Zhang, Ya-hui; Zhang, Cheng; Wang, Ding-yong; Luo, Cheng-zhong; Yang, Xi; Xu, Feng

2015-12-01

To preliminarily discuss the mercury emission characteristics and its mass balance in each process of the iron and steel production, a typical iron and steel enterprise was chosen to study the total mercury in all employed materials and estimate the input and output of mercury during the steel production process. The results showed that the mercury concentrations of input materials in each technology ranged 2.93-159.11 µg · kg⁻¹ with the highest level observed in ore used in blast furnace, followed by coal of sintering and blast furnace. The mercury concentrations of output materials ranged 3.09-18.13 µg · kg⁻¹ and the mercury concentration of dust was the highest, followed by converter slag. The mercury input and the output in the coking plant were 1346.74 g · d⁻¹ ± 36.95 g · d⁻¹ and 177.42 g · d⁻¹ ± 13.73 g · d⁻¹, respectively. In coking process, mercury mainly came from the burning of coking coal. The sintering process was the biggest contributor for mercury input during the iron and steel production with the mercury input of 1075. 27 g · d⁻¹ ± 60.89 g · d⁻¹ accounting for 68.06% of the total mercury input during this production process, and the ore powder was considered as the main mercury source. For the solid output material, the output in the sintering process was 14.15 g · d⁻¹ ± 0.38 g · d⁻¹, accounting for 22.61% of the total solid output. The mercury emission amount from this studied iron and steel enterprise was estimated to be 553.83 kg in 2013 with the emission factor of 0.092 g · t⁻¹ steel production. Thus, to control the mercury emissions, iron and steel enterprises should combine with production practice, further reduce energy consumption of coking and sintering, or improve the quality of raw materials and reduce the input of mercury.

Suitability of iron ore tailings and quarry dust as fine aggregates for ...

African Journals Online (AJOL)

Eight concrete mixes were produced with different levels of sand replacement by either iron ore tailings or quarry dust, while the ninth mix of 100 % river sand served as the control. The highest 28-day compressive strength of 29.2 N/mm2 was obtained by blending 75 % sand and 25 % quarry dust with cement, which was 7 ...

Experimental study and modelling of iron ore reduction by hydrogen; Etude experimentale et modelisation de la reduction du minerai de fer par l'hydrogene

Energy Technology Data Exchange (ETDEWEB)

Wagner, D

2008-01-15

In an effort to find new ways to drastically reduce the CO{sub 2} emissions from the steel industry (ULCOS project), the reduction of iron ore by pure hydrogen in a shaft furnace was investigated. The work consisted of literature, experimental, and modelling studies. The chemical reaction and its kinetics were analysed on the basis of thermogravimetric experiments and physicochemical characterizations of partially reduced samples. A specific kinetic model was designed, which simulates the successive reactions, the different steps of mass transport, and possible iron sintering, at the particle scale. Finally, a 2-dimensional numerical model of a shaft furnace was developed. It depicts the variation of the solid and gas temperatures and compositions throughout the reactor. One original feature of the model is using the law of additive characteristic times for calculating the reaction rates. This allowed us to handle both the particle and the reactor scale, while keeping reasonable calculation time. From the simulation results, the influence of the process parameters was assessed. Optimal operating conditions were concluded, which reveal the efficiency of the hydrogen process. (author)

Four magnetite generations in the Precambrian Varena Iron Ore deposit, SE Lithuania, as a result of rock-fluid interactions

Science.gov (United States)

Skridlaite, Grazina; Prusinskiene, Sabina; Siliauskas, Laurynas

2017-04-01

Iron ores in Precambrian crystalline basement of the Varena area, SE Lithuania, were discovered during the detail geological-geophysical exploration in 1982-1992. They are covered with 210-500 m thick sediments. The Varena Iron Ore deposit (VIOD) may yield from 71 to 219.6 million tons of iron ore according to different economic evaluations (Marfin, 1996). They were assumed to be of metasomatic and hydrothermal origin, however several other hypotheses explaining the VIOZ origin, e.g. as a layered mafic or carbonatite intrusions were also suggested. Magnetites of the VIOD were thoroughly investigated by the Cameca SX100 microprobe at the Warsaw University and by the Quanta 250 Energy Dispersive Spectroscopy (EDS) at the Nature Research Centre in Vilnius, Lithuania. Four generations of magnetite were distinguished in the studied serpentine-magnetite ores (D8 drilling) and were compared with the earlier studied and reference magnetites. The earliest, spinel inclusion-rich magnetite cores (Mag-1) have the highest trace element contents (in wt%): Si (0.032), Al (0.167-0.248), Mg (0.340-0.405), Ti (0.215-0.254), V (0.090-0.138) etc. They might have formed during an early metamorphism and/or related skarn formation. Voluminous second magnetite (Mag-2) replacing olivine, pyroxenes, spinel and other skarn minerals at c. 540o C (Magnetite-Ilmenite geothermometer) has much lower trace element abundances, probably washed out by hydrothermal fluids. The latest magnetites (Mag-3 and Mag-4) overgrow the earlier ones and occur near or within the sulfide veins (Mag-4). As was observed from microtextures, the Mag-3 and Mag-4 have originated from the late thermal reworking by dissolution-reprecipitation processes. To imply an origin of the studied magnetites, they were compared to the earlier studied magmatic-metamorphic (1058 drilling), presumably skarn (982 drilling) magnetites from the studied area and plotted in the major magnetite ore type fields according to Dupuis and Beaudoin

Phase change of iron ore reduction process using EFB as reducing agent at 900-1200°C

Science.gov (United States)

Purwanto, H.; Salleh, H. M.; Rozhan, A. N.; Mohamad, A. S.; Zakiyuddin, A.

2018-04-01

Treatment of low grade iron ore involved reduction of oxygen in iron oxide by using reductant such as carbon monoxide or hydrogen gas. Presently, carboneous materials such as coke/coal are widely used as a source to provide reducing gas, but some problem arises from this material as the gas can harm the environments. Therefore, empty fruit bunch biomass from oil palm becomes an alternative to replace the usage of coke/coal as their major composition is carbon and hydrogen. The idea of replacing coke with biomass will reduce the amount of carbon dioxide release as biomass is a carbon neutral and renewable source, and at the same time abundance of waste from oil palm industries can be overcome. Therefore, the aim of this research is to upgrade the low grade iron with reducibility more than 50% being used in iron and steel making. In this research, low grade iron ore are mixed together with EFB then is making into composite pellet before being reduced at certain parameter chosen. The variables involved in this research is composition EFB (10%, 30% and 50%), temperature (1000°C, 1100°C and 1200°C) and reduction time is fixed with 30 minutes. From the experiment conducted, the highest reducibility achieved is 76.37% at temperature 1200°C. While XRD analysis shows the existence of metallic iron phase started to form at 1000°C with composition of 30% of EFB. Meanwhile, from magnetization test show that at 1200°C the highest magnetic susceptibility is achieved as the dominance phase at 1200°C is metallic phase. Therefore it is an interesting alternative to replace coke with biomass for reducing agent in upgrading low grade iron into workable ores.

26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Gain or loss upon the disposal of coal or...) Sales and Exchanges § 1.631-3 Gain or loss upon the disposal of coal or domestic iron ore with a... under section 272, shall be gain or loss upon the sale of the coal or iron ore. See paragraph (b)(4) of...

Tribological behaviour and statistical experimental design of sintered iron-copper based composites

Science.gov (United States)

Popescu, Ileana Nicoleta; Ghiţă, Constantin; Bratu, Vasile; Palacios Navarro, Guillermo

2013-11-01

The sintered iron-copper based composites for automotive brake pads have a complex composite composition and should have good physical, mechanical and tribological characteristics. In this paper, we obtained frictional composites by Powder Metallurgy (P/M) technique and we have characterized them by microstructural and tribological point of view. The morphology of raw powders was determined by SEM and the surfaces of obtained sintered friction materials were analyzed by ESEM, EDS elemental and compo-images analyses. One lot of samples were tested on a "pin-on-disc" type wear machine under dry sliding conditions, at applied load between 3.5 and 11.5 × 10-1 MPa and 12.5 and 16.9 m/s relative speed in braking point at constant temperature. The other lot of samples were tested on an inertial test stand according to a methodology simulating the real conditions of dry friction, at a contact pressure of 2.5-3 MPa, at 300-1200 rpm. The most important characteristics required for sintered friction materials are high and stable friction coefficient during breaking and also, for high durability in service, must have: low wear, high corrosion resistance, high thermal conductivity, mechanical resistance and thermal stability at elevated temperature. Because of the tribological characteristics importance (wear rate and friction coefficient) of sintered iron-copper based composites, we predicted the tribological behaviour through statistical analysis. For the first lot of samples, the response variables Yi (represented by the wear rate and friction coefficient) have been correlated with x1 and x2 (the code value of applied load and relative speed in braking points, respectively) using a linear factorial design approach. We obtained brake friction materials with improved wear resistance characteristics and high and stable friction coefficients. It has been shown, through experimental data and obtained linear regression equations, that the sintered composites wear rate increases

Recovery and separation of iron from iron ore using innovative fluidized magnetization roasting and magnetic separation

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Yu J.

2018-01-01

Full Text Available In this investigation, a pilot-scale fluidized magnetization roasting reactor was introduced and used to enhance magnetic properties of iron ore. Consequently, the effects of roasting temperature, reducing gas CO flow rate, and fluidizing gas N2 flow rate on the magnetization roasting performance were studied. The results indicated that the hematite was almost completely converted into magnetite by a gas mixture of 4 Nm3/h CO and 1 Nm3/h N2 at roasting temperature of 540°C for about 30 s. Under optimized conditions, a high grade concentrate containing 66.84% iron with iron recovery of 91.16% was achieved. The XRD, VSM, and optical microscopy (OM analyses revealed that most of the hematite, except some coarse grains, was selectively converted to magnetite, and that the magnetic properties were greatly enhanced. Thus, their separation from non-magnetic gangue minerals was facilitated.

Applicability of attrition of iron ore in floating; Aplicabilidade da atricao do minerio de ferro na flotacao

Energy Technology Data Exchange (ETDEWEB)

Fortes, Fabiana Fonseca

2010-07-01

The aim of this study is to investigate the possibility to increase metal recovery in the flotation of iron ore with the implementation of a stage of scrubbing followed by dispersion. The minerals in question stems from two mines located in the western portion of the Iron Quadrangle and differ mainly with respect to the percentage of hematite and porous and the presence of aggregated masses. These characteristics were compared to those of other minerals that have succeeded with the adoption of this technique. Tests were conducted at bench scale scrubbing, desliming and concentration by flotation with the blend of ore from both mines. Were varied stirring time and pH. The chemical results of desliming and flotation products in the different conditions were compared. The presence of porous hematite is relevant in a mine, mainly due to the occurrence of earthy goethite, alumina carrier of the contaminant. The step desliming is insufficient for the removal of harmful sludge flotation. Laboratory experiments showed that the scrubbing of the pulp of iron ore of Minas de Capitao do Mato and Tamandua, agitated for 10 minutes followed by desliming amid scattered, promotes increased metal recovery by about 17% and increases the selectivity of 40 % compared to the results of the scrubbing and without dispersion. The scrubbing of hematite ore followed by desliming amid scattered can bring gains in improving the quality of pellet feed fine if deployed industrially. (author)

Strain-enhanced sintering of iron powders

Energy Technology Data Exchange (ETDEWEB)

Amador, D.R.; Torralba, J.M. [Universidad Carlos III de Madrid, Departamento de Ciencias de Materiales e Ingenieria Metalurgica, Leganes, Madrid (Spain); Monge, M.A.; Pareja, R. [Universidad Carlos III de Madrid, Departamento de Fisica, Madrid (Spain)

2005-02-01

Sintering of ball-milled and un-milled Fe powders has been investigated using dilatometry, X-ray, density, and positron annihilation techniques. A considerable sintering enhancement is found in milled powders showing apparent activation energies that range between 0.44 and 0.80 eV/at. The positron annihilation results, combined with the evolution of the shrinkage rate with sintering temperature, indicate generation of lattice defects during the sintering process of milled and un-milled powders. The sintering enhancement is attributed to pipe diffusion along the core of moving dislocations in the presence of the vacancy excess produced by plastic deformation. Positron annihilation results do not reveal the presence of sintering-induced defects in un-milled powders sintered above 1200 K, the apparent activation energy being in good agreement with that for grain-boundary diffusion in {gamma}-Fe. (orig.)

Dissolution of copper and iron from malachite ore and precipitation of copper sulfate pentahydrate by chemical process

OpenAIRE

H. Kokes; M.H. Morcali; E. Acma

2014-01-01

The present work describes an investigation of a chemical process for the recovery of copper and iron from malachite ore. For the dissolution of copper and iron, H2SO4 was employed as well as H2O2 as an oxidizing agent. The effects of reaction temperature and time, acid concentration, liquid-to-solid ratio and agitation rate on the copper and iron percentage were investigated. Following the steps of dissolving the copper and iron sulfate and filtering, iron (III) hydroxide was precipitated by...

Use of neutron capture gamma radiation for determining grade of iron ore in blast holes and exploration holes

International Nuclear Information System (INIS)

Eisler, P.L.; Huppert, P.; Mathew, P.J.; Wylie, A.W.; Youl, S.F.

1977-01-01

Neutron radiative capture and neutron-neutron logging have been applied to determining the grade of ore in dry blast holes and a dry exploration hole drilled into a layered iron deposit. Both thermal and epithermal neutron responses were measured as well as the gamma-ray responses due to neutron capture by iron and by hydrogen present in hydrated minerals. The results were fitted by a stepwise multiple linear regression technique to give expressions for mean grade of ore in the drill hole and 95% confidence intervals for estimation of this mean. For an overall range of ore grades of 20-68% Fe and a mean grade of 63% Fe, the confidence interval for prediction of mean grade for the neutron-gamma technique was 0.3% Fe for pooled data from all five blast holes and 0.8% Fe for a single hole. It was also shown that for this type of layered deposit a simpler neutron-neutron log incorporating simultaneous measurement of both thermal and epithermal neutron responses gave almost as good a grade prediction result for pooled results from five drill holes, namely 63+-0.4% Fe, as that obtained by the neutron-gamma technique. The results of both types of log are compared with those obtained by the spectral gamma-ray backscattering [Psub(z)] technique, or by logging of natural gamma radiations from the shale component of the ore. From this comparison conclusions are drawn regarding the most suitable technique to employ for determining grade of iron ore in various practical logging situations. (author)

Contribution to the study of the sintering of ex-carbonyl iron in the α and γ phases using the micro-fractographic technique

International Nuclear Information System (INIS)

Oxley Gaborit de Montjou, M.Th.

1966-01-01

The micro-fractographic study of the sintering of ex-carbonyl iron has shown or confirmed a number of phenomena of which the principal are as followed: Sintering in the a phase: -) existence of two stages of sintering differentiated by the type of rupture (inter or trans-crystalline); -) marked influence of the content of oxygen in the atmosphere and in the initial compressed sample on the speed of sintering; -) formation of striations on the grain-boundary surfaces and on the inner surface of pores caused by the presence of oxygen. Sintering in the γ phase: -) a pronounced decrease in the speed of sintering: the grains in the initial powder remain in the granular state within the final α crystal in the iron sintered in the lower γ range even after several hours of sintering; -) this granular structure can be eliminated by intermediate compression thus enabling the sintering process to proceed. A considerable decrease in the speed of sintering if the A 3 point is passed one or more times in the α range sintering. A high speed sintering if the treatment in the γ range is carried out at or above 1300 C. The results of this study agree with micrographic investigation as well as with dilatometric measurements and known auto-diffusion coefficients. (author) [fr

Moisture measurement in the iron and steel industry: experience with nuclear moisture measurements in coke, and studies of infrared moisture measurement of iron ore mixtures

International Nuclear Information System (INIS)

Beumer, J.A.; Wouters, M.

1976-01-01

In the heavy iron-making industry there are several processes for which it is necessary to measure on-line the moisture content of certain process materials, especially in the field of iron ore preparation and blast furnace practice. Two examples are given. (1) Experience with nuclear moisture-measurements in coke covers a period of ten years in which eight measuring systems have been installed in the weighing hoppers of blast furnaces. The standard deviation is about 0.7% moisture in the range 0 to 15% moisture. The way the method is used, the safety measures and the difficulties encountered, especially the effect on recalibration of neutron-absorbing materials in photomultipliers are described. (2) The application of infrared absorption to the study of moisture measurment or iron ore mixtures is described. With an ore mixture for pellets manufacture, a rather dark ore mixture, problems have arisen concerning the sensitivity. The reference and measuring wavelengths now in use are 2.51 and 2.95 μm. In this case the absorption of the energy is rather high. The results may be improved by using quartz optics instead of the normal Pyrex ones, as the cut-off wavelength of Pyrex is about 3 μm. Variations due to colour and specific surface have been studied. As the accuracy required is +- 0.1% moisture in the range 8 to 12% moisture, these variations need to be eliminated. (author)

Sinterability and microstructure evolution during sintering of ferrous powder mixtures

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Kétner Bendo Demétrio

2013-01-01

Full Text Available The present work is focused on ferrous powder metallurgy and presents some results of a development of a suitable masteralloy for use as an additive to iron powder for the production of sintered steels. The masteralloy was produced by melting a powder mixture containing approximately Fe + 20% Ni + 20% Mn + 20% Si + 1% C (wt%, in order to obtain a cast billet that was converted into fine powder by crushing and milling. It was observed presence of SiC in the masteralloy after melting that is undesirable in the alloy. Si element should be introduced by using ferrosilicon. Sintered alloys with distinct contents of alloying elements were prepared by mixing the masteralloy powder to plain iron powder. Samples were produced by die compaction of the powder mixtures and sintering at 1200 °C in a differential dilatometer in order to record their linear dimensional behaviour during heating up and isothermal sintering, aiming at studying the sinterability of the compacts. Microstructure development during sintering was studied by SEM, XRD and microprobe analyses.

Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

Science.gov (United States)

Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

2015-04-01

The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

Moisture measurements in iron ores, in freight cars, through nuclear techniques

International Nuclear Information System (INIS)

Castagnet, A.C.; Said, M.; Duarte, U.

1975-01-01

The possibility and the advantages of using a nuclear technique for measuring on the spot (in the freight cars) and the moisture content of iron ores are described. The measurements included the determination of the volumetric moisture content and the density. From this values, the moisture content in percentage by weight was calculated. Nuclear Chicago d/M Combination Density-Moisture Probe with a 5 mCi Ra/Be source, and a digital portable scaler, were used. The investigated techniques give good results when the measurements are made directly on the ore surface, and has economical advantages over the gravimetric method by sampling. The probable reasons for both, the aleatory scattering of points and the lack of linear correlation between the values of both methods, when the nuclear measurement is made across the car walls are analized

Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

Science.gov (United States)

Polat, Gökhan; Birol, Burak; Sarıdede, Muhlis Nezihi

2014-08-01

The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate (PET), because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450°C for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron (iron nuggets) were reduction at 1450°C for 10 min using composite pellets containing 60% PET and 40% coke.

Determination of aluminium in iron ores and ferroalloys by complexometry

International Nuclear Information System (INIS)

Tikhonov, V.N.; Grigorovich, L.F.

1977-01-01

The present method is based on fusing iron ore samples and ferroalloys with NaOH, leaching of the alloy in water, and complexometric estimation of aluminium in the filtrate by back titration of excess EDTA with a CuSO 4 solution in the presence of a glycine-thymol blue tracer, using NaF to increase selectivity. The final titration point is fixed by means of a photoelectrical titrator. Fifty-fold amounts of Cu(2), Mg, Zn, In, Pb, Fe(3) and Ni, twenty-five-fold amounts of Ca, Sr and Cd, ten-fold amounts of Co, five-fold amounts of Hg(2), Bi and Mo(6), two-fold amounts of Mn, and equal amounts of Ga, Tl(3), Zr, V(5) and W(6) do not impede determination. Determination is impeded by metals that form strong fluoride complexes with Sc, Y, rare-earth elements, Ti(4), Sn(2) and V(4), even when those metals are contained in equal amounts; it is also impeded by equal amounts of Cr(3). The selectivity of the given method has been compared with that of methods involving titration with a solution constituting zinc chloride with xylenol orange and with a solution comprising copper chloride and sulphur chrome-azurol in the presence of cytil trimethyl ammonium. The method is more selective. A hexamethylenetetramine buffer solution has been used to obtain an optimum (pH 6) medium. The above procedure is employed to assay standard ferroboron samles of iron ore

Microbial Reducibility of Fe(III Phases Associated with the Genesis of Iron Ore Caves in the Iron Quadrangle, Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Ceth W. Parker

2013-11-01

Full Text Available The iron mining regions of Brazil contain thousands of “iron ore caves” (IOCs that form within Fe(III-rich deposits. The mechanisms by which these IOCs form remain unclear, but the reductive dissolution of Fe(III (hydroxides by Fe(III reducing bacteria (FeRB could provide a microbiological mechanism for their formation. We evaluated the susceptibility of Fe(III deposits associated with these caves to reduction by the FeRB Shewanella oneidensis MR-1 to test this hypothesis. Canga, an Fe(III-rich duricrust, contained poorly crystalline Fe(III phases that were more susceptible to reduction than the Fe(III (predominantly hematite associated with banded iron formation (BIF, iron ore, and mine spoil. In all cases, the addition of a humic acid analogue enhanced Fe(III reduction, presumably by shuttling electrons from S. oneidensis to Fe(III phases. The particle size and quartz-Si content of the solids appeared to exert control on the rate and extent of Fe(III reduction by S. oneidensis, with more bioreduction of Fe(III associated with solid phases containing more quartz. Our results provide evidence that IOCs may be formed by the activities of Fe(III reducing bacteria (FeRB, and the rate of this formation is dependent on the physicochemical and mineralogical characteristics of the Fe(III phases of the surrounding rock.

Iron ore particles on four seaweed species from Camburi Beach (Espírito Santo state, Brazil

Directory of Open Access Journals (Sweden)

Cristina Aparecida Gomes Nassar

2006-09-01

Full Text Available The present study estimated the iron-ore concentration found on four species of seaweed. The species tested grow on a site heavily contaminated by this ore, in the city of Vitória, state of Espírito Santo, Brazil. Under natural conditions, the iron ore reached a temperature 5.0ºC higher than the sand on a sunny day. All the species had iron ore adhered to their fronds. Udotea cyathiformis was the species with the highest iron-ore concentration varing from 0.07 to 0.90 g wet weight, followed by Lobophora variegata (from 0.07 to 0.62 g wet weight, Padina gymnospora (from 0.08 to 0.55 g wet weight and Ulva fasciata (from 0.05 to 0.25 g wet weight. Even after four changes of water over a 12-hour period, the fronds still had particles adhered to their outside cell wall. All the species showed similar tendencies to release the iron, with the highest percentage of particles (40 to 60% released in the first change of water.Minério de ferro particulado sobre quatro macroalgas da Praia de Camburi (Estado do Espírito Santo-Brasil. O presente trabalho determinou a concentração de minério de ferro presente em quatro macroalgas. As espécies testadas ocorrem em um local extremamente contaminado por este particulado, na cidade de Vitória, Estado do Espírito Santo, Brasil. Sob condições naturais, o minério de ferro alcançou um temperatura de até 5,0ºC acima da temperatura da areia em um dia ensolarado.Todas as espécies estudadas apresentavam minério em suas paredes externas. A espécie Udotea cyathiformis apresentou a maior concentração de minério em sua fronde variando de 0,07 a 0,90 g massa úmida, seguida por Lobophora variegata (de 0,07 a 0,62 g massa úmida, Padina gymnospora (de 0,08 a 0,55 g massa úmida e Ulva fasciata (de 0,05 a 0,25 g massa úmida. Mesmo após sucessivas trocas de água, as frondes ainda apresentavam partículas aderidas às suas paredes celulares externas. As espécies apresentaram a mesma tendência de libera

Strength and fracture mechanism of iron reinforced tricalcium phosphate cermet fabricated by spark plasma sintering.

Science.gov (United States)

Tkachenko, Serhii; Horynová, Miroslava; Casas-Luna, Mariano; Diaz-de-la-Torre, Sebastian; Dvořák, Karel; Celko, Ladislav; Kaiser, Jozef; Montufar, Edgar B

2018-05-01

The present work studies the microstructure and mechanical performance of tricalcium phosphate (TCP) based cermet toughened by iron particles. A novelty arises by the employment of spark plasma sintering for fabrication of the cermet. Results showed partial transformation of initial alpha TCP matrix to beta phase and the absence of oxidation of iron particles, as well as a lack of chemical reaction between TCP and iron components during sintering. The values of compressive and tensile strength of TCP/Fe cermet were 3.2 and 2.5 times, respectively, greater than those of monolithic TCP. Fracture analysis revealed the simultaneous action of crack-bridging and crack-deflection microstructural toughening mechanisms under compression. In contrast, under tension the reinforcing mechanism was only crack-bridging, being the reason for smaller increment of strength. Elastic properties of the cermet better matched values reported for human cortical bone. Thereby the new TCP/Fe cermet has potential for eventual use as a material for bone fractures fixation under load-bearing conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

NARCIS (Netherlands)

Pereira, A.A.; van Hattum, A.G.M.; Brouwer, A.; van Bodegom, P.M.; Rezende, C.E.; Salomons, W.

2008-01-01

In water systems, water quality and geochemical properties of sediments determine the speciation of trace metals, metal transport, and sediment-water exchange, influencing metal availability and its potential effects on biota. Studies from temperate climates have shown that iron-ore mining and

Trace-element and multi-isotope geochemistry of Late-Archean black shales in the Carajas iron-ore district, Brazil

DEFF Research Database (Denmark)

Cabral, A. R.; Creaser, R. A.; Naegler, T.

2013-01-01

The 250-300-m-thick Carajas Formation in the Carajas mineral province, northern Brazil, consists of banded iron formation (including giant high-grade iron-ore deposits) and minor black shale, overlying a thick pile (2-3 km) of about 2.75-Ga-old metabasalt. Carbonaceous shale with pyrite-and local...

CHAIN EXTENDER AND EMULSIFIER APPLICATION IN IRON ORE FLOTATION

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José Pedro da Silva

2013-06-01

Full Text Available The present study aims to evaluate the reverse flotation performance of iron ore, using collector (amine, in the presence and absence of chain extender (diesel oil and emulsifier (sodium lauryl sulfate.Six tests were realized with duplicate. Tests using amine, diesel oil and sodium lauryl sulphate show the better results, with metallurgical recovery of 91.82% and the concentrate silica equal 1.68%. Thus, it is found that the use of emulsifier and chain extender together with the amine, shows better results in the flotation, in terms of metal recovery and selectivity, when compared to using only amine or amine and diesel oil.

Nuclear techniques for bulk ore analysis and their application to quality control

International Nuclear Information System (INIS)

Holmes, R.J.

1981-01-01

Bulk analysis techniques developed for the mining industry in which analyses are obtained directly from 3-30kg ore samples or from ore on conveyor belts are outlined. They include the determination of iron in iron ores from backscattered gamma radiation, shale in sedimentary iron ores from natural gamma activity, iron from a thermal-neutron capture reaction, and aluminium from the thermal neutron activation reaction

RECOVERY OF IRON FROM LOW-GRADE HEMATITE ORE USING COAL-BASED DIRECT REDUCTION FOLLOWED BY MAGNETIC SEPARATION

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N. Alavifard

2016-09-01

Full Text Available In the present work, iron recovery from a low-grade hematite ore (containing less than 40% iron, which is not applicable in common methods of ironmaking, was studied. Non-coking coal was used as reducing agent. Reduction experiments were performed under various coal to hematite ratios and temperatures. Reduction degree was calculated using the gravimetric method. Reduced samples were subjected to magnetic separation followed by X-ray diffraction analysis. Total iron content, degree of metallization and recovery efficiency in magnetic part were determined by quantitative chemical analysis, which were obtained about 82%, 95% and 64% respectively under optimal conditions. CaO as an additive improved ore reducibility and separation efficiency. The microstructure of reduced samples and final products were analyzed by scanning electron microscopy. Final product with a high degree of metallization can be used in steel making furnaces and charging of blast furnaces which can improve production efficiency and decrease coke usage.

The GENIALL process for generation of nickel-iron alloys from nickel ores or mattes

International Nuclear Information System (INIS)

Diaz, G.; Frias, C.; Palma, J.

2001-01-01

A new process, called GENIALL (acronym of Generation of Nickel Alloys), for nickel recovery as ferronickel alloys from ores or mattes without previous smelting is presented in this paper. Its core technology is a new electrolytic concept, the ROSEL cell, for electrowinning of nickel-iron alloys from concentrated chloride solutions. In the GENIALL Process the substitution of iron-based solid wastes as jarosite, goethite or hematite, by saleable ferronickel plates provides both economic and environmental attractiveness. Another advantage is that no associated sulfuric acid plant is required. The process starts with leaching of the raw material (ores or mattes) with a solution of ferric chloride. The leachate liquor is purified by conventional methods like cementation or solvent extraction, to remove impurities or separate by-products like copper and cobalt. The purified solution, that contains a mixture of ferrous and nickel chlorides is fed to the cathodic compartment of the electrowinning cell, where nickel and ferrous ions are reduced together to form an alloy. Simultaneously, ferrous chloride is oxidized to ferric chloride in the anodic compartment, from where it is recycled to the leaching stage. The new electrolytic equipment has been developed and scaled up from laboratory to pilot prototypes with commercial size electrodes of 1 m 2 . Process operating conditions have been established in continuous runs at bench and pilot plant scale. The technology has shown a remarkable capacity to produce nickel-iron alloys of a wide range of compositions, from 10% to 80% nickel, just by adjusting the operating parameters. This emerging technology could be implemented in many processes in which iron and other non-ferrous metals are harmful impurities to be removed, or valuable metals to be recovered as a marketable iron alloy. Other potential applications of this technology are regeneration of spent etching liquors, and iron removal from aqueous effluents. (author)

Territorial pattern and classification of soils of Kryvyi Rih Iron-Ore Basin

OpenAIRE

О. О. Dolina; О. М. Smetana

2014-01-01

The authors developed the classification of soils and adapted it to the conditions of Krivyi Rih industrial region. It became the basis for determining the degree of soil cover transformation in the iron-ore basin under technogenesis. The classification represents the system of hierarchical objects of different taxonomic levels. It allows determination of relationships between objects and their properties. Researched patterns of soil cover structures’ distribution were the basis for the relev...

Iron ore pollution in Mandovi and Zuari estuarine sediments and its fate after mining ban.

Science.gov (United States)

Kessarkar, Pratima M; Suja, S; Sudheesh, V; Srivastava, Shubh; Rao, V Purnachandra

2015-09-01

Iron ore was mined from the banded iron formations of Goa, India, and transported through the Mandovi and Zuari estuaries for six decades until the ban on mining from September 2012. Here we focus on the environmental magnetic properties of sediments from the catchment area, upstream and downstream of these estuaries, and adjacent shelf during peak mining time. Magnetic susceptibility (χ lf) and saturation isothermal remanent magnetization (SIRM) values of sediments were highest in upstream (catchment area and estuaries), decreased gradually towards downstream (catchment area and estuaries), and were lowest on the adjacent shelf. The χ lf values of the Mandovi estuary were two to fourfold higher than those in the Zuari. The sediments of these two estuaries after the mining ban showed enrichment of older magnetite and sharp decrease in the SIRM values. Although the input of ore material has been reduced after mining ban, more flushing of estuarine sediments is required for healthier environment.

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: Potential use in environmental risk assessment

Energy Technology Data Exchange (ETDEWEB)

Rust Neves, Natalia; Oliva, Marco Antonio; Cruz Centeno, Danilo da; Costa, Alan Carlos; Ferreira Ribas, Rogerio [Departamento de Biologia Vegetal, Universidade Federal de Vicosa, Av. PH Rolfs, Campus, Vicosa, Minas Gerais, 36570-000 (Brazil); Gusmao Pereira, Eduardo, E-mail: egpereira@gmail.com [Departamento de Biologia Vegetal, Universidade Federal de Vicosa, Av. PH Rolfs, Campus, Vicosa, Minas Gerais, 36570-000 (Brazil)

2009-06-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM{sub Fe}) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM{sub Fe} application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: Potential use in environmental risk assessment

International Nuclear Information System (INIS)

Rust Neves, Natalia; Oliva, Marco Antonio; Cruz Centeno, Danilo da; Costa, Alan Carlos; Ferreira Ribas, Rogerio; Gusmao Pereira, Eduardo

2009-01-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM Fe ) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM Fe application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Iron Ore Industry Emissions as a Potential Ecological Risk Factor for Tropical Coastal Vegetation

Science.gov (United States)

Kuki, Kacilda N.; Oliva, Marco A.; Pereira, Eduardo G.

2008-07-01

In the coastal zone of the Espírito Santo state, Brazil, fragments of restinga, which form a natural ecosystem, share their space with an increasing number of iron ore industries. The iron ore dust and SO2 originating from the industry processing activities can interfere with the vegetation of the adjacent ecosystems at various levels. This study was undertaken in order to evaluate the effects of industry emissions on representative members of the restinga flora, by measuring physiological and phenological parameters. Foliar samples of Ipomoea pes caprae, Canavalia rosea, Sophora tomentosa, and Schinus terebinthifolius were collected at three increasing distances from an ore industry (1.0, 5.0, and 15.0 km), and were assessed for their dust deposition, chlorophyll, and Fe content. Phenological monitoring was focused on the formation of shoots, flowers, and fruits and was also performed throughout the course of a year. The results showed that the edaphic characteristics and the mineral constitutions of the plants were affected by industry emissions. In addition, the chlorophyll content of the four species increased with proximity to the industry. Phenological data revealed that the reproductive effort, as measured by fruit production, was affected by emissions and S. tomentosa was the most affected species. The use of an integrative approach that combines biochemical and ecological data indicates that the restinga flora is under stress due to industry emissions, which on a long-term basis may put the ecosystem at risk.

[Iron ore, economic geology and networks of experts between Wisconsin and the state of Minas Gerais, 1881-1914].

Science.gov (United States)

Fischer, Georg

2014-01-01

This article deals with the "discovery" of Brazilian iron ore from two perspectives. The first examines the increasing emphasis of the geosciences and their practical application and global reach since the second half of the nineteenth century. While in Brazil economic geology was integrated step by step into state institutions, at the global level it experienced its moment of triumph with the 11th International Geological Congress in 1910. The second deals with a specific social network with a decisive role in the race for Brazilian iron ore: with transnational experts juggling between the logic of the market and that of the academy. The article reveals the importance of local negotiations in the incorporation of the subsoil of Minas Gerais into the global space of mining.

The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

Science.gov (United States)

Zhou, Qiying; Jiang, Xia; Li, Xi; Jiang, Wenju

2016-09-01

In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

Mineralogy and geochemistry of banded iron formation and iron ...

Indian Academy of Sciences (India)

The geological complexities of banded iron formation (BIF) and associated iron ores of Jilling–. Langalata iron ore ...... sure to sea water. Uranium in these samples varies ..... Ce oxidation and removal (Elderfield and Greaves. 1982; De Baar et ...

APPLICATION OF MAGNETIC SURVEY TO EXPLORE THE IRON ORE DEPOSITS IN THE NUSAWUNGU COASTAL REGENCY OF CILACAP CENTRAL JAVA

Directory of Open Access Journals (Sweden)

S Sehah

2017-12-01

Full Text Available The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores in the rock.

Dissolution of copper and iron from malachite ore and precipitation of copper sulfate pentahydrate by chemical process

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H. Kokes

2014-03-01

Full Text Available The present work describes an investigation of a chemical process for the recovery of copper and iron from malachite ore. For the dissolution of copper and iron, H2SO4 was employed as well as H2O2 as an oxidizing agent. The effects of reaction temperature and time, acid concentration, liquid-to-solid ratio and agitation rate on the copper and iron percentage were investigated. Following the steps of dissolving the copper and iron sulfate and filtering, iron (III hydroxide was precipitated by adjusting the pH level of the solution. Subsequently, copper sulfate pentahydrate was obtained by using various precipitants (i.e. ethanol, methanol and sulfuric acid.

Effects of CaO on the compaction and sintering by plasma of Powder-metallurgical iron

Science.gov (United States)

Ariza Suarez, H. G.; Sarmiento Santos, A.; Ortiz Otálora, C. A.

2017-12-01

This work the effect of the addition of Calcium Oxide (CaO) in the compaction and sintering of powder metallurgical iron Ancoor Steel 1000® is studied. Iron samples were made with proportions of: 0.5%, 1%, 1.5% and 2% by weight of CaO. The samples were sintered in a luminescent discharge furnace, in an atmosphere of H2+Ar at a temperature of 1150°C. XRD analysis was used to determine the formation of compounds, this analysis evidenced the formation of: hematite and magnetite, which were found both on the surface and in the volume. A characterization of the ability to protect against corrosive effects was carried out using the EIS electrochemical impedance spectroscopy method on the samples, in a solution of 1000ppm of chloride, with this procedure it was found that at a concentration of 0.5% and 1% CaO, the electrochemical impedance value is increased with values of 11.7MΩ, 2.2MΩ respectively.

Territorial pattern and classification of soils of Kryvyi Rih Iron-Ore Basin

Directory of Open Access Journals (Sweden)

О. О. Dolina

2014-10-01

Full Text Available The authors developed the classification of soils and adapted it to the conditions of Krivyi Rih industrial region. It became the basis for determining the degree of soil cover transformation in the iron-ore basin under technogenesis. The classification represents the system of hierarchical objects of different taxonomic levels. It allows determination of relationships between objects and their properties. Researched patterns of soil cover structures’ distribution were the basis for the relevant mapping and classification of soils. The classification is adapted to highly-influential industrial conditions of soils formation in the region. The adaptation measures were specific classification levels and units, which provided more detailed differentiation of soils. The authors proposed to separate the soils by the degree of soil formation potential realization for super-divisions. The potential determination allowed predicting the outcome of soil formation and identification of transformation degree of soil cover structures in the region. The results indicated that the main type of soil structures in the industrial region was represented by primitive soils (indicated as a separate type. These soils were determined as dynamic elements in the structure of industrial region soil cover. The article indicated that presence of soil cover structures with the domination of technogenic soils, particularly post-technogenic soils, was the marker of the soil cover in Krivyi Rih Iron-Ore Basin

Calibration equations for energy-dispersive XRF determination of copper, iron and lead in copper ore slurries

International Nuclear Information System (INIS)

Lakosz, M.

1976-01-01

Calibration equations for the X-ray fluorescence analysis determination of copper, iron and lead in copper ore slurries have been derived and tested. The measurement of Ksub(α) lines of copper and iron and Lsub(α) line of lead excited by rays from 238 Pu source have been used. Si/Li detector coupled to multichannel analyzer and minicomputer have been applied in measurements. The matrix and density effect have been eliminated by additional measurement of back-scattered primary radiation. (author)

Automatic control system for uniformly paving iron ore pellets

Science.gov (United States)

Wang, Bowen; Qian, Xiaolong

2014-05-01

In iron and steelmaking industry, iron ore pellet qualities are crucial to end-product properties, manufacturing costs and waste emissions. Uniform pellet pavements on the grate machine are a fundamental prerequisite to ensure even heat-transfer and pellet induration successively influences performance of the following metallurgical processes. This article presents an automatic control system for uniformly paving green pellets on the grate, via a mechanism mainly constituted of a mechanical linkage, a swinging belt, a conveyance belt and a grate. Mechanism analysis illustrates that uniform pellet pavements demand the frontend of the swinging belt oscillate at a constant angular velocity. Subsequently, kinetic models are formulated to relate oscillatory movements of the swinging belt's frontend to rotations of a crank link driven by a motor. On basis of kinetic analysis of the pellet feeding mechanism, a cubic B-spline model is built for numerically computing discrete frequencies to be modulated during a motor rotation. Subsequently, the pellet feeding control system is presented in terms of compositional hardware and software components, and their functional relationships. Finally, pellet feeding experiments are carried out to demonstrate that the control system is effective, reliable and superior to conventional methods.

Evaluation of physical health and its relation with history of work accidents in workers of the Central Iron Ore Company of Iran

Directory of Open Access Journals (Sweden)

Gholam Hossein Halvani

2013-01-01

Full Text Available Aims: This study was conducted to determine the state of physical symptoms of the Iranian Central Iron Ore Company workers and its relation with history of work accidents. Materials and Methods: This cross-sectional descriptive study was performed at the Iranian Central Iron Ore Company and included 388 workers sampled randomly out of 2100 workers. Research tool was a two-part questionnaire that its reliability was determined by some of researchers. Data was analyzed by SPSS (Statistical Package for Social Science software and statistical tests included variance analysis and Pearson′ correlation tests. Results: According to the findings, 80.9% had favorable physical health conditions and there was a significant relationship between physical health condition, history of work accidents, cigarette smoking and type of work. Conclusion: Considering the strong relationship between physical health and history of work accidents, it is proposed that high-level managers of the Central Iron Ore Company of Iran should pay special attention to the improvement of physical health, psychological, social, and welfare levels.

Ecological aspects of air pollution from an iron-sintering plant at Wawa, Ontario

Energy Technology Data Exchange (ETDEWEB)

Gordon, A G; Gorham, E

1963-01-01

At Wawa, in northern Ontario, vegetation has been damaged severely by sulphur dioxide pollution from an iron-sintering plant. Damage is mainly restricted to a narrow strip northeast from the sinter plant, since southwest winds are strongly predominant. It is traceable from the air for at least 20 miles in this direction and is estimated as severe within 11 miles and very severe within 5 miles. Within about 10 miles NE. From the sinter plant ground flora variety declines markedly, from about 20-40 species per 40 square meter quadrant beyond this distance to 0-1 species within 2 miles of the pollution source. At the same time sulphate in lake and pond waters increases greatly, from normal levels of about 0.2-0.3 milliequivalents per liter to more than 0.5 meq/l within 11 miles NE and up to 2 meq/l within 2 miles NE from the sinter plant. Waters within about 5 miles NE are strongly acid (pH 3.2-3.8), but are not low in calcium. Soluble sulphate in the surface soil rises sharply within about 4 miles NE from the pollution source, where, also, soil erosion is very pronounced, though traceable farther out. The phanerogms most tolerant of air pollution are Polygonum cilinode and Sambucus pubens, which are infrequent in the normal forest vegetation. In quadrant studies along a northeast transect, seedlings of Pinus strobus were not observed within 30 miles from the sinter plant, while those of Picea glauca, P. mariana, and Populus tremuliodes were not recorded within 15 miles.

Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

Directory of Open Access Journals (Sweden)

Wenguang Du

2017-01-01

Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

Microstructural development and mechanical properties of iron based cermets processed by pressureless and spark plasma sintering

International Nuclear Information System (INIS)

Alvaredo, P.; Gordo, E.; Van der Biest, O.; Vanmeensel, K.

2012-01-01

Highlights: ► Processing of Fe-based cermets by pressureless sintering and spark plasma sintering. ► Influence of carbon content on the sintering mechanism and hardness. ► The cermet phase diagram was calculated and permits to explain the microstructure. ► SPS provides ferritic matrix and different carbide distribution than CPS samples. ► Pressureless sintered samples contain retained austenite at room temperature. - Abstract: Iron-based cermets are an interesting class of metal-ceramic composites in which properties and the factors influencing them are to be explored. In this work the metal matrix contains Cr, W, Mo and V as alloying elements, and the hard phase is constituted by 50 vol% of titanium carbonitride (TiCN) particles. The work studies the influence of the C content and the processing method on the sinterability, microstructure and hardness of the developed cermet materials. For that purpose, cermet samples with different C content in the matrix (0 wt%, 0.25 wt%, 0.5 wt%, 1.0 wt%) were prepared by conventional pressureless sintering (CPS) and, in order to achieve finer microstructures and to reduce the sintering time, by spark plasma sintering (SPS). The density and hardness (HV30) of the processed materials was evaluated, while their phase composition and microstructure was characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The equilibrium phase diagram of the composite material was calculated by ThermoCalc software in order to elucidate the influence of the carbon content on the obtained phases and developed microstructures.

Fundamental study on carbon composite iron ore hot briquette used as blast furnace burden

Energy Technology Data Exchange (ETDEWEB)

Chu, Man-sheng; Liu, Zheng-gen; Wang, Zhao-cai [Institute of Ferrous Metallurgy, Northeastern University, Shenyang (China); Yagi, Jun-ichiro [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University (Japan)

2011-05-15

Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%-50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi-fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Photodegradation of UHMWPE filled with iron ore fine

Energy Technology Data Exchange (ETDEWEB)

Morais, Frederick Louis Dias de; Sousa, Alexandre Rangel de, E-mail: rangel@deii.cefetmg.br [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil). Departamento de Engenharia de Materiais; Medeiros, Felipe da Silva; Silva, Glaura Goulart [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Quimica; Rabello, Marcelo Silveira [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

2017-03-15

Ultra high molecular weight polyethylene (UHMWPE) is one of the most important engineering materials owing to outstanding properties like impact strength and abrasion resistance. However, the relatively low Young's modulus restricts some application and the use of fillers may be a suitable way to overcome this. The fillers can influence the photo stabilization of the compound, as it occurs to other polymers. Neat UHMWPE and its composites with 1 and 10% of iron ore fine were exposed to ultraviolet radiation for up to 33 days and then tested for mechanical properties. The stress-strain behaviour changed with degradation, with an evident necking and strain hardening region that was not observed before exposure, due to a reduction in entanglements density. From the tensile results, the filler may have a protection action against UV, particularly when a loading of 10% was present. Complementary analyses were performed, including X-ray diffraction, DSC and SEM. (author)

Up-gradation of MoO{sub 3} and separation of copper, iron, zinc from roasted molybdenum ore by a leaching process

Energy Technology Data Exchange (ETDEWEB)

Jin-Young, Lee; Jyothi Rajesh, Kumar; Ho-Seok, Jeon; Joon-Soo, Kim, E-mail: rajeshkumarphd@rediffmail.com, E-mail: rkumarphd@kigam.re.kr [Extractive Metallurgy Department, Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM) (Korea, Republic of)

2013-04-15

The present research paper deals with the oxidation process of molybdenum ore. The main target of the present study is the up-gradation of MoO{sub 3} from roasted molybdenum ore by a leaching process without waste generation. The most important application of hydrometallurgical processing is the leaching process of the ore and it is the primary process to make pure metal from ore. The present investigations optimize the following experimental parameters to improve the concentration of MoO{sub 3} as well as the separation of copper, iron and zinc in roasted molybdenum ore: effect of acid concentration, temperature, pulp density and leaching time were studied systematically. The temperature study was carried out at 550-595 Degree-Sign C for the oxidation process. The XRD result shows that oxidation process of molybdenum ore and SEM pictures were taken for particles before and after the oxidation process at 585 Degree-Sign C for 360 min. (author)

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L.

Science.gov (United States)

Kuki, Kacilda Naomi; Oliva, Marco Antônio; Pereira, Eduardo Gusmão; Costa, Alan Carlos; Cambraia, José

2008-09-15

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions.

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L

Energy Technology Data Exchange (ETDEWEB)

Kuki, Kacilda Naomi [Departamento de Biologia Vegetal, Universidade Federal de Vicosa (Brazil)], E-mail: naomikuki@hotmail.com; Oliva, Marco Antonio; Pereira, Eduardo Gusmao; Costa, Alan Carlos [Departamento de Biologia Vegetal, Universidade Federal de Vicosa (Brazil); Cambraia, Jose [Departamento de Biologia Geral, Universidade Federal de Vicosa (Brazil)

2008-09-15

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions.

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L

International Nuclear Information System (INIS)

Kuki, Kacilda Naomi; Oliva, Marco Antonio; Pereira, Eduardo Gusmao; Costa, Alan Carlos; Cambraia, Jose

2008-01-01

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions

Anti frictional materials iron-pig iron-brass manufacture using shaving waste products of pig-iron

International Nuclear Information System (INIS)

Nasamov, S. N.; Krivij, N.; Gudenau, H. W.; Babich, A. I.; Garcia, L. L.; Formoso, A.; Cores, A.

2003-01-01

Parts based on iron and steel powders are widely used in the manufacture of automobile and domestic equipment. This work was done to study the anti-friction properties of iron-pig iron-brass compositions of materials which were obtained by pressing and sintering from a mix of iron powders and industrial by products of cast-iron turnings, brass, talc and technical sulphur. Experiments were performed using cold pressure technology in the flowing matrix of the powder composite without solid lubricants. The subsequent sintering was carried out at 1200 degree centigree under isothermal conditions in a nitrogen atmosphere in the sintering zone during 1 h. The physical-mechanical and anti-friction properties were almost double by the active drainage of the gases from the compression mould. The study of the microstructure of the sintered materials showed that free cementite existed between the particle limits and around the pores. large agglomerations of dark inclusions could be observed, consisting of graphite, zinc and iron oxides, which were points of tension in the materials that reduce its durability and, therefore, its wear resistance to dry friction. (Author) 34 refs

Intensification of the Reverse Cationic Flotation of Hematite Ores with Optimization of Process and Hydrodynamic Parameters of Flotation Cell

Science.gov (United States)

Poperechnikova, O. Yu; Filippov, L. O.; Shumskaya, E. N.; Filippova, I. V.

2017-07-01

The demand of high grade iron ore concentrates is a major issue due to the depletion of rich iron-bearing ores and high competitiveness in the iron ore market. Iron ore production is forced out to upgrade flowsheets to decrease the silica content in the pelettes. Different types of ore have different mineral composition and texture-structural features which require different mineral processing methods and technologies. The paper presents a comparative study of the cationic and anionic flotation routes to process a fine-grain oxidized iron ore. The modified carboxymethyl cellulose was found as the most efficient depressant in reverse cationic flotation. The results of flotation optimization of hematite ores using matrix of second-order center rotatable uniform design allowed to define the collector concentration, impeller rotation speed and air flowrate as the main flotation parameters impacting on the iron ore concentrate quality and iron recovery in a laboratory flotation machine. These parameters have been selected as independent during the experiments.

Final report to United Nations Industrial development organization on evaluation of tender for the Valentine iron ore project in Uruguay

International Nuclear Information System (INIS)

1981-01-01

The Government of Uruguay (Project Authorities)is desirous of improving their national economy through exploitation of resources with which the nation is endowed. Studies so far conducted in Uruguay reveal that the Valentine iron ore deposits amount to about 30 million tons with an average Fe-content of 331; an additional probable reserve of about 17 million tons is also expected. The Project Authorities have been examining the possibility of exploiting these iron reserves for the establishment of a viable iron and steel complex within the country.

Work stressors, job insecurity, union support, job satisfaction and safety outcomes within the iron ore mining environment

Directory of Open Access Journals (Sweden)

Nicolaas W.H. Smit

2016-08-01

Full Text Available Orientation: The study of work stressors, job insecurity and union support creates opportunity for iron ore mining organisations to manage job satisfaction and safety motivation and behaviour more effectively. Research purpose: The objective of this study was to investigate the relationship between work stressors, job insecurity, union support, job satisfaction and safety motivation and behaviour of a sample of iron ore mine workers in South Africa. Motivation for the study: The mining industry in general is often faced with hazardous and physically demanding working environments, where employees work under constant pressure. Work stressors, job insecurity, union support and job satisfaction are considered key variables when investigating effective means of managing safety. Research design, approach and method: A cross-sectional survey design was utilised to collect the data. A convenience sample of employees in the iron ore mining industry of South Africa (N = 260 were included. Structural equation modelling and bootstrapping resampling analysis were used to analyse the data. Main findings: Work stressors and job insecurity were found to be negatively associated with job satisfaction. Conversely, perceived union support was positively associated with job satisfaction and safety motivation and behaviour. Furthermore, job satisfaction mediated the relationship between union support and safety motivation and behaviour. Practical/managerial implications: Mining organisations can, by placing the focus on reducing work stressors, and promoting job security and union support, achieve higher levels of safety motivation and behaviour through job satisfaction. Contribution/value-add: A great deal of independent research on work stressors, job insecurity, union support, job satisfaction as well as safety motivation and behaviour has already been done. To date, very little empirical research exists that simultaneously considers all these constructs. This

Strength and Microstructure of Concrete with Iron Ore Tailings as Replacement for River Sand

Directory of Open Access Journals (Sweden)

Umara Shettima Ali

2018-01-01

Full Text Available River Sand is one of the basic ingredients used in the production of concrete. Consequently, continuous consumption of sand in construction industry contributes significantly to depletion of natural resources. To achieve more sustainable construction materials, this paper reports the use of iron ore tailings (IOT as replacement for river sand in concrete production. IOT is a waste product generated from the production of iron ore and disposed to land fill without any economic value. Concrete mixtures containing different amount of IOT were designed for grade C30 with water to cement ratio of 0.60. The percentage ratios of the river sand replacements by IOT were 25%, 50%, 75% and 100%. Concrete microstructure test namely, XRD and Field Emission Scanned Electron Microscopic/Energy dispersive X-ray Spectroscopy (FESEM/EDX were conducted for control and IOT concretes in order to determine the interaction and performance of the concrete containing IOT. Test results indicated that the slump values of 130 mm and 80 to 110 mm were recorded for the control and IOT concretes respectively. The concrete sample of 50% IOT recorded the highest compressive strength of 37.7 MPa at 28 days, and the highest flexural strength of 5.5 MPa compared to 4.7 MPa for reference concrete. The texture of the IOT is rough and angular which was able to improve the strength of the concrete.

Strength and Microstructure of Concrete with Iron Ore Tailings as Replacement for River Sand

Science.gov (United States)

Umara Shettima, Ali; Ahmad, Yusof; Warid Hussin, Mohd; Zakari Muhammad, Nasiru; Eziekel Babatude, Ogunbode

2018-03-01

River Sand is one of the basic ingredients used in the production of concrete. Consequently, continuous consumption of sand in construction industry contributes significantly to depletion of natural resources. To achieve more sustainable construction materials, this paper reports the use of iron ore tailings (IOT) as replacement for river sand in concrete production. IOT is a waste product generated from the production of iron ore and disposed to land fill without any economic value. Concrete mixtures containing different amount of IOT were designed for grade C30 with water to cement ratio of 0.60. The percentage ratios of the river sand replacements by IOT were 25%, 50%, 75% and 100%. Concrete microstructure test namely, XRD and Field Emission Scanned Electron Microscopic/Energy dispersive X-ray Spectroscopy (FESEM/EDX) were conducted for control and IOT concretes in order to determine the interaction and performance of the concrete containing IOT. Test results indicated that the slump values of 130 mm and 80 to 110 mm were recorded for the control and IOT concretes respectively. The concrete sample of 50% IOT recorded the highest compressive strength of 37.7 MPa at 28 days, and the highest flexural strength of 5.5 MPa compared to 4.7 MPa for reference concrete. The texture of the IOT is rough and angular which was able to improve the strength of the concrete.

A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation.

Science.gov (United States)

Cele, Emmanuel Nkosinathi; Maboeta, Mark

2016-01-01

An iron ore mine site in Swaziland is currently (2015) in a derelict state as a consequence of past (1964-1988) and present (2011 - current) iron ore mining operations. In order to control problems associated with mine wastes, the Swaziland Water Services Corporation (SWSC) recently (2013) proposed the application of biosolids in sites degraded by mining operations. It is thought that this practice could generally improve soil conditions and enhance plant reestablishment. More importantly, the SWSC foresees this as a potential solution to the biosolids disposal problems. In order to investigate the effects of biosolids and plants in soil physicochemical conditions of iron mine soils, we conducted two plant growth trials. Trial 1 consisted of tailings that received biosolids and topsoil (TUSB mix) while in trial 2, tailings received biosolids only (TB mix). In the two trials, the application rates of 0 (control), 10, 25, 50, 75 and 100 t ha(-1) were used. After 30 days of equilibration, 25 seeds of Cynodon dactylon were sown in each pot and thinned to 10 plants after 4 weeks. Plants were watered twice weekly and remained under greenhouse conditions for 12 weeks, subsequent to which soils were subjected to chemical analysis. According to the results obtained, there were significant improvements in soil parameters related to fertility such as organic matter (OM), water holding capacity (WHC), cation exchange capacity (CEC), ammonium [Formula: see text] , magnesium (Mg(2+)), calcium (Ca(2+)) and phosphorus ( [Formula: see text] ). With regard to heavy metals, biosolids led to significant increases in soil total concentrations of Cu, Zn, Cd, Hg and Pb. The higher concentrations of Zn and Cu in treated tailings compared to undisturbed adjacent soils are a cause for concern because in the field, this might work against the broader objectives of mine soil remediation, which include the recolonization of reclaimed sites by soil-dwelling organisms. Therefore, while

Chloride pyrometallurgy of uranium ore. 1. Chlorination of phosphate ore using solid or gas chlorinating agent and carbon

International Nuclear Information System (INIS)

Taki, Tomihiro; Komoto, Shigetoshi; Otomura, Keiichiro; Takenaka, Toshihide; Sato, Nobuaki; Fujino, Takeo.

1995-01-01

A thermodynamical and pyrometallurgical study to recover uranium from the phosphate ores was undertaken using the chloride volatilization method. Iron was chlorinated with solid chlorinating agents such as NaCl and CaCl 2 in combination with activated carbon, which will be used for removing this element from the ore, but uranium was not. On the other hand, the chlorination using Cl 2 gas and activated carbon gave a good result at 1,223 K. Not only uranium but also iron, phosphorus, aluminum and silicon were found to form volatile chlorides which vaporized out of the ore, while calcium remained in the ore as non-volatile CaCl 2 . The chlorination condition was studied as functions of temperature, reaction time and carbon content. The volatilization ratio of uranium around 95% was obtained by heating the mixture of the ore and activated carbon (35 wt%) in a mixed gas flow of Cl 2 (200 ml/min) and N 2 (200 ml/min) at 1,223 K for 120 min. (author)

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.

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.

Microstructure and properties of multiphase sintered cermets Fe-Fe2B

International Nuclear Information System (INIS)

Nowacki, J.; Klimek, L.

1998-01-01

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe 2 B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe 2 B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe 2 B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe 2 B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe 2 B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe 2 B cermets are a composite material in which iron boride, Fe 2 B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe 2 B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe 2 B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above, resulting from the cermet

Flocculation of chromite ore fines suspension using polysaccharide ...

Indian Academy of Sciences (India)

Unknown

liquid separation. Keywords. Flocculation; graft copolymer; mineral industry effluent; chromite ore fines; ... work well as flocculating agent on coal washery effluent, copper and iron ore fines etc (Karmakar et al 1998, 1999;. Tripathy et al 2001).

Report on Evaluation of Tender for the Valentine Iron Ore Project in Uruguay

International Nuclear Information System (INIS)

1981-01-01

This report prepared by Dastur Engineering International GmbH (DEI)Consulting Engineers, Dusseldorf at the instance of United Nations Industrial Development Organization (UNIDO) seeks to present an evaluation of the feasibility study presented by Republica Oriental del Uruguay, Ministerio de Industria y- Energia (Project Authority) by the Brazilian Consortium (comprising Tenenga, Coferraz, Cimetal and Interbras) along with a project BID including financing possibilities. In accordance with the contract requirements, this Draft Final Report is being submitted. Based on the comments to be received on the findings incorporated in this Draft Final Report from UNIDO and Project Authorities in Uruguay, the Final Report will be prepared and submitted to UNIDO in accordance with the time schedule stipulated in the contract between UNIDO and DEI. The aims of the Project are:a) The development objective is the utilisation of the country's natural resources by exploiting the iron ore deposits of Valentines, for iron and steel production. b)The immediate objective is to evaluate the tenders for the execution of a project to undertake the industrial exploitation of the iron or deposits in close co-operation and co-ordination with the Uruguayan authorities.

One step sintering of homogenized bauxite raw material and kinetic study

Science.gov (United States)

Gao, Chang-he; Jiang, Peng; Li, Yong; Sun, Jia-lin; Zhang, Jun-jie; Yang, Huan-ying

2016-10-01

A one-step sintering process of bauxite raw material from direct mining was completed, and the kinetics of this process was analyzed thoroughly. The results show that the sintering kinetics of bauxite raw material exhibits the liquid-phase sintering behavior. A small portion of impurities existed in the raw material act as a liquid phase. After X-ray diffraction analyses, scanning electron microscopy observations, and kinetics calculations, sintering temperature and heating duration were determined as the two major factors contributing to the sintering process and densification of bauxite ore. An elevated heating temperature and longer duration favor the densification process. The major obstacle for the densification of bauxite material is attributed to the formation of the enclosed blowhole during liquid-phase sintering.

Study on uranium loss during 'Iron-Gypsum Cake' precipitation from acid leach liquor of Jaduguda ore using factorially designed experiments

International Nuclear Information System (INIS)

Das, Amrita; Yadav, Manoj; Chatterjee, Ankur; Singh, A.K.; Hubli, R.C.

2012-01-01

Acid leaching process for uranium recovery from ore often generates considerable amounts of impurities into the solution. It is a challenge to separate the non-valuable impurities as manageable and stable waste products for final disposal, without losing the valuable constituents. The main impurities that come with the leach liquor are iron and sulfate. Their removal is essential for meeting the iron requirement in leaching circuit and also for making the effluent suitable for recycle. Factorial design analysis was applied to study of process variables for precipitation of iron and sulphate from leach liquor with composition using CaO as precipitation reagent

Rapid photometric determination of phosphorus in iron ores and related materials as phosphomolybdenum-blue.

Science.gov (United States)

Bhargava, O P; Gmitro, M

1984-04-01

A rapid, simple and accurate method for determining phosphorus photometrically in iron ores and related materials, obviating the use of perchloric acid, is described. The sample is fused with sodium peroxide in a zirconium crucible and the melt dissolved in hydrochloric acid. The molybdenum-blue complex is developed by the addition of ammonium molybdate and hydrazine sulphate and the absorbance is measured at 725 nm. The range of the method is from 0.005 to 1.0% P. A batch of 6 samples can be analysed in about 2 hr.

A New Direction for Biomining: Extraction of Metals by Reductive Dissolution of Oxidized Ores

Directory of Open Access Journals (Sweden)

Kevin B. Hallberg

2013-01-01

Full Text Available Biomining, the biotechnology that uses microorganisms to extract metals from ores and concentrates, is currently used exclusively for processing reduced ores and mine wastes. Metals of economic value also occur extensively in oxidized ores, such as nickel laterites. While these are not amenable to oxidative dissolution, the ferric iron minerals they contain can, in theory, be disrupted by iron reduction, causing associated metals to be released. We have harnessed the ability of the facultatively anaerobic, acidophilic bacterium Acidithiobacillus ferroooxidans to couple the oxidation of elemental sulphur to the reduction of ferric iron in the goethite fraction of a limonitic nickel ore at 30 °C. Nickel and other metals (Co, Cr and Mn were effectively solubilised and maintained in solution due to the low pH (1.8 of the leach liquor. The results highlight the potential for the bioprocessing of oxidized, iron-rich ores using an approach that is energy-saving and environmentally-benign compared with metallurgical processes currently applied to the extraction of Ni from lateritic ores.

Reaction behavior of SO2 in the sintering process with flue gas recirculation.

Science.gov (United States)

Yu, Zhi-Yuan; Fan, Xiao-Hui; Gan, Min; Chen, Xu-Ling; Chen, Qiang; Huang, Yun-Song

2016-07-01

The primary goal of this paper is to reveal the reaction behavior of SO2 in the sinter zone, combustion zone, drying-preheating zone, and over-wet zone during flue gas recirculation (FGR) technique. The results showed that SO2 retention in the sinter zone was associated with free-CaO in the form of CaSO3/CaSO4, and the SO2 adsorption reached a maximum under 900ºC. SO2 in the flue gas came almost from the combustion zone. One reaction behavior was the oxidation of sulfur in the sintering mix when the temperature was between 800 and 1000ºC; the other behavior was the decomposition of sulfite/sulfate when the temperature was over 1000ºC. However, the SO2 adsorption in the sintering bed mainly occurred in the drying-preheating zone, adsorbed by CaCO3, Ca(OH)2, and CaO. When the SO2 adsorption reaction in the drying-preheating zone reached equilibrium, the excess SO2 gas continued to migrate to the over-wet zone and was then absorbed by Ca(OH)2 and H2O. The emission rising point of SO2 moved forward in combustion zone, and the concentration of SO2 emissions significantly increased in the case of flue gas recirculation (FGR) technique. Aiming for the reuse of the sensible heat and a reduction in exhaust gas emission, the FGR technique is proposed in the iron ore sintering process. When using the FGR technique, SO2 emission in exhaust gas gets changed. In practice, the application of the FGR technique in a sinter plant should be cooperative with the flue gas desulfurization (FGD) technique. Thus, it is necessary to study the influence of the FGR technique on SO2 emissions because it will directly influence the demand and design of the FGD system.

Using Local Event Tomography to Image Changes in the Rock Mass in the Kiirunavaara Iron Ore Mine, Northern Sweden

Science.gov (United States)

Lund, B.; Berglund, K.; Tryggvason, A.; Dineva, S.; Jonsson, L.

2017-12-01

Although induced seismic events in a mining environment are a potential hazard, they can be used to gain information about the rock mass in the mine which otherwise would be very difficult to obtain. In this study we use approximately 1.2 million mining induced seismic events in the Kiirunavaara iron ore mine in northernmost Sweden to image the rock mass using local event travel-time tomography. The Kiirunavaara mine is the largest underground iron ore mine in the world. The ore body is a magnetite sheet of 4 km length, with an average thickness of 80 m, which dips approximately 55° to the east. The events are of various origins such as shear slip on fractures, non-shear events and blasts, with magnitudes of up to 2.5. We use manually picked P- and S-wave arrival times from the routine processing in the tomography and we require that both phases are present at at least five geophones. For the tomography we use the 3D local earthquake tomography code PStomo_eq (Tryggvason et al., 2002), which we adjusted to the mining scale. The tomographic images show clearly defined regions of high and low velocities. Prominent low S-velocity zones are associated with mapped clay zones. Regions of ore where mining is ongoing and the near-ore tunnel infrastructure in the foot-wall also show generally low P- and S-velocities. The ore at depths below the current mining levels is imaged both as a low S-velocity zone but even more pronounced as a high Vp/Vs ratio zone. The tomography shows higher P- and S-velocities in the foot-wall away from the areas of mine infrastructure. We relocate all 1.2 million events in the new 3D velocity model. The relocation significantly enhances the clarity of the event distribution in space and we can much more easily identify seismically active structures, such as e.g. the deformation of the ore passes. The large number of events makes it possible to do detailed studies of the temporal evolution of stability in the mine. We present preliminary results

The potentialities of nuclear geophysical methods in ore testing of ferrous metals

International Nuclear Information System (INIS)

Ochkur, A.P.; Voznesenskij, L.I.; Fedorov, S.V.

1976-01-01

To study iron ores of simple composition, the gamma-gamma method is used successfully, determining iron contents in boreholes, in the walls of mine workings and in sampling hacked off rocks. The X-ray diffraction method is used effectively in analysing iron ores of complex composition ensuring that the contents of Fe, Mn and Ca are determined in them. Neutron-capture spectrometric gamma-logging is a promising method for determining the total iron content in the mined ore. Manganese ores are singled out in the boreholes by data from thermal neutron and neutron-activation logging. The X-ray diffraction method is used to analyse powder samples in mine workings. To single out and estimate chromites in boreholes, a combination of neutron-capture spectrometric gamma-logging, gamma-gamma logging and epithermal neutron-neutron logging is used. The X-ray diffraction method determines the contents of Cr, Ca and Fe in powder and coarse-ground samples of chromites

Ore potential of basic rocks in Finland

International Nuclear Information System (INIS)

Reino, J.; Ekberg, M.; Heinonen, P.; Karppanen, T.; Hakapaeae, A.; Sandberg, E.

1993-02-01

The report is associated with a study programme on basic rocks, which has the aim to complement the preliminary site investigations on repository for TVO's (Teollisuuden Voima Oy) spent nuclear fuel. The report comprises a mining enterprise's view of the ore potential of basic plutonic rocks in Finland. The ores associated with basic plutonic rocks are globally known and constitute a significant share of the global mining industry. The ores comprise chromium, vanadium-titanium-iron, nickel-copper and platinum group element ores. The resources of the metals in question and their mining industry are examined globally. A review of the use of these metals in the industry is presented as well. General factors affecting the mining industry, such as metal prices, political conjunctures, transport facilities, environmental requirements and raw material sources for the Finnish smelters have been observed from the point of view of their future effect on exploration activity and industrial development in Finland. Information on ores and mineralizations associated with Finnish basic rocks have been compiled in the report. The file comprises 4 chromium occurrences, 8 vanadium-titanium-iron occurrences, 13 PGE occurrences and 38 nickel-copper occurrences

Is outdoor work associated with elevated rates of cerebrovascular disease mortality? A cohort study based on iron-ore mining.

Science.gov (United States)

Björ, Ove; Jonsson, Håkan; Damber, Lena; Burström, Lage; Nilsson, Tohr

2016-01-01

A cohort study that examined iron ore mining found negative associations between cumulative working time employed underground and several outcomes, including mortality of cerebrovascular diseases. In this cohort study, and using the same group of miners, we examined whether work in an outdoor environment could explain elevated cerebrovascular disease rates. This study was based on a Swedish iron ore mining cohort consisting of 13,000 workers. Poisson regression models were used to generate smoothed estimates of standardized mortality ratios and adjusted rate ratios, both models by cumulative exposure time in outdoor work. The adjusted rate ratio between employment classified as outdoor work ≥25 years and outdoor work 0-4 years was 1.62 (95 % CI 1.07-2.42). The subgroup underground work ≥15 years deviated most in occurrence of cerebrovascular disease mortality compared with the external reference population: SMR (0.70 (95 % CI 0.56-0.85)). Employment in outdoor environments was associated with elevated rates of cerebrovascular disease mortality. In contrast, work in tempered underground employment was associated with a protecting effect.

Evaluation of exploitation alternatives of iron - titanium - vanadium ore from Campo Alegre de Lourdes (Bahia-Brazil)

International Nuclear Information System (INIS)

Cassa, J.C.S.; Ogasawara, T.; Silva, F.T. da; Cuellar, O.D.

1987-01-01

An evaluation of experiences carried out in order to develop an economic process for vanadium, is presented. The attempts which are being developed in the Metallurgical Engineering Program at COPPE/UFRJ, are described, and the other technical and economical possibilities of existing technologies, are analysed. The advantages and disadvantages of integrated steel making process to recover iron, titanium and vanadium contained in the ore from Campo Alegre de Lourdes deposit, in Bahia-Brazil are considered. (Author) [pt

Radioisotope devices at Novo-Krivorozhskij-ore-enrichment plant

International Nuclear Information System (INIS)

Levitskij, V.Ya.; Kucher, V.G.; Ministerstvo Chernoj Metallurgii Ukrainskoj SSR, Dnepropetrovsk, Bazovaya Opytno-Konstruktorskaya Izotopnaya lab.)

1975-01-01

Use of the ''Ferrite'' analyzers, AZhR and PAZh-1 and the GR-7 gamma relay in different engineering areas of the Novo-Krivorozh ore-enrichment plant is evaluated. The ''Ferrite'' radioisotopic analyzer was designed for rapid roentgeno-radiometric determination of the total iron and iron group element contents in powdered samples of ores and products of their treatment. From the density of the flux of the characteristic radiation it is possible to determine quantitatively the content of the element of interest in the analyzed material. The radioisotpic analyzer AZhR-1 is distinguished by its high efficiency in the analysis for total iron on products of processing of iron ore raw materials. The use of this apparatus allows complete replacement of the chemical method for rapid analysis of concentrates by the roentgeno-radiometric method, which decreases the total analytical work on determination of total iron and speeds up output of information on concentrate quality. The radioisotopic gamma analyzer PAZh-1 is designed for automatic and either continuous or discrete measurement of the total iron content in iron ore materials ground to 50 mm, carried on a conveyor, without selection or preparation of the samples for analysis. The analyzer operates on the principle of measuring the average frequency of impingement on a detector of gamma quanta back-scattered by the analyzed material. This frequency is determined by the percentage content of total iron in the material. The apparatus operates continuously. The mean square deviation of the apparatus values from chemical data is 0.93% Fesub(total). Use of the apparatus greatly increases the operativeness of the control and decreases the laboriousness of raw material sampling in an engineering stream. The radioisotopic data units GR-7 are designed for control of the level of materials in hoppers for recovery and burning of agglomerates. Use of this apparatus showed its great advantage over data units of other types

A procedure for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores

International Nuclear Information System (INIS)

Zubcek, L.; Baloun, S.; Martinek, K.; Vebr, Z.; Krepelka, J.; Lasica, S.

1989-01-01

It is suggested that dust from the production of ferroalloys of manganese, particularly ferrosilicomanganese and ferromanganese, can be conveniently used for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores. This dust contains 30 to 40% oxides of manganese, about one-half of this is MnO 2 . Iron in the dust is present in the trivalent form, and the dust is pefectly dry. The conventional grinding of oxidants for the ore processing is eliminated, the dust being available in particle size below 0.2 mm. The dust is added in amounts of 5 to 100 kg per ton of the ore, and the suspension is typically heated at 115 degC for 3.5 hr. (P.A.)

Summary of the mineralogy of the Colorado Plateau uranium ores

Science.gov (United States)

Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

1956-01-01

In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

Sustainability in pelletizing iron ore through the Industrial Ecology and Cleaner Production Program

Directory of Open Access Journals (Sweden)

Cristiano Farias Coelho

2013-06-01

Full Text Available This study aims to analyze the practices of a pelletizing iron ore industry with respect to adoption of pollution prevention measures, suggested by applying the concepts of Cleaner Production and Material Flow Analysis. The technical procedure adopted was the case study, the data collection was done through direct observation, with field research and literature review. The main results were obtained from analysis of company reports available to the public, but require a more detailed quantification of data. The study concludes that the identification of environmental opportunities is possible through the proposed implementation of Cleaner Production program, which provides better results when combined with the precepts of the industrial ecology tool, the Material Flow Analysis.

Spatial evolution of Zn-Fe-Pb isotopes of sphalerite within a single ore body: A case study from the Dongshengmiao ore deposit, Inner Mongolia, China

Science.gov (United States)

Gao, Zhaofu; Zhu, Xiangkun; Sun, Jian; Luo, Zhaohua; Bao, Chuang; Tang, Chao; Ma, Jianxiong

2018-01-01

Analyses of sphalerite minerals from the characteristic brecciated Zn-Pb ores of the main ore body in the giant Dongshengmiao deposit have revealed variations in δ66Zn from 0.17 to 0.40‰ and in δ56Fe from -1.78 to -0.35‰. Further, the investigated pyrrhotite samples have iron that is isotopically similar to that of associated sphalerite minerals. The most distinctive pattern revealed by the zinc and iron isotope data is the lateral trend of increasing δ66Zn and δ56Fe values from southwest to northeast within the main ore body. The lead isotopic homogeneity of ore sulfides from the main ore body suggests that there is only one significant source for metal, thus precluding the mixing of multiple metal sources as the key factor controlling spatial variations of zinc and iron isotopes. The most likely control on spatial variations is Rayleigh fractionation during hydrothermal fluid flow, with lighter Zn and Fe isotopes preferentially incorporated into the earliest sulfides to precipitate from fluids. Precipitations of sphalerite and pyrrhotite have played vital roles in the Zn and Fe isotopic variations, respectively, of the ore-forming system. Accordingly, the larger isotopic variability for Fe than Zn within the same hydrothermal system perhaps resulted from a larger proportion of precipitation for pyrrhotite than for sphalerite. The lateral trend pattern revealed by the zinc and iron isotope data is consistent with the occurrence of a cystic-shaped breccia zone, which is characterized by marked elevation in Cu. The results further confirm that Zn and Fe isotopes can be used as a vectoring tool for mineral prospecting.

The potential for ore and industrial minerals in the Forsmark area

Energy Technology Data Exchange (ETDEWEB)

Lindroos, Hardy [MIRAB Mineral Resurser AB, Uppsala (Sweden); Isaksson, Hans; Thunehed, Hans [GeoVista AB, Luleaa (Sweden)

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc

The potential for ore and industrial minerals in the Forsmark area

International Nuclear Information System (INIS)

Lindroos, Hardy; Isaksson, Hans; Thunehed, Hans

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc, although

Chemical effects of Iron-ore mining and processing at Itakpe, Kogi State

International Nuclear Information System (INIS)

Audu, D. A.; Ibeanu, I. G. E.; Yusuf, J. Z.

2011-01-01

X-ray fluorescence (XRF) technique was employed to generate data from soil samples collected from mine, industrial plant, and mill tailing deposit sites of National Iron-Ore Mining Project, Itakpe, Kogi State. The vertical profile analysis showed that As, Pb, Th, and U which are all toxic have their highest mean values of 91±8(81-100), 138±28(110-183), 49±12(39-68), and 37±2(34-40) ppm, respectively at the tailing deposit site. The result also showed a common occurrence of high concentrations of Pb and As at some depths in the vertical profiles after initial decline from the earth surface at the three sites thereby suggesting that absolute reclamation of old mines may not be possible immediately and that any new use or practice of such reclaimed mines should be carefully chosen. Correlation coefficients between arsenic and Pb, Cu, Mn, Zn, and Fe, at the industrial plant site (which is very close to an unmodified environment) were 0.997, 0.942, 0.896, 0.972, and 0.932, respectively. These values therefore suggest strong associations of As with ores of these minerals. The soil samples mean pH value of 6.5±0.1(5.7-7.2) was measured indicating non existence of Acid Mine Drainage at the company.

CHARACTERIZATION OF METAL GRADES IN A STOCKPILE OF AN IRON MINE (CASE STUDY- CHOGHART IRON MINE, IRAN

Directory of Open Access Journals (Sweden)

Francesco Tinti

2018-01-01

Full Text Available In any mining operation due to the cut-off grade (economic criteria, materials classify into the ore and waste. The material with grade equal to or higher than the cut-off grade is considered as ore and the material with grade less than the cut-off grade is transported as wastes to the waste dumps. However, because of increasing metal demand, depleting of in situ ore reserves and so the reduction of cut-off grades for many metals, the mentioned waste dumps were considered as valuable ore reserves named stockpiles. In this paper, multivariate geostatistics was used to estimate the iron grades of two stockpiles following the sequential of piling procedures from the main source - the ore deposit - to the piling field. One stockpile is characterized by phosphorous concentration ((P % > 0.6 %, while the other by iron concentration ((Fe %< 50%. Since economic and physical constraints made sampling physically and economically problematic, the grade distribution and variability were estimated on the basis of primary blast-hole data from the main ore body and the mine’s long-term planning policy. A geostatistical model was applied to the excavated part of the iron deposit and the stockpile, by reconstructing ore selection, haulage and piling method. Results were validated through spatial variability of iron and phosphorous concentrations by comparing grade variability (Fe and P with mining and pilling units. This methodology allows characterizing the iron grades within stockpiles without any extra sampling.

The determination of Fe, Mn and Ca in sintered iron and blast-furnace slag by X-ray fluorescent analyses of energy and wave dispersion-comparison of results

International Nuclear Information System (INIS)

Dworak, B.; Gajek, Sz.

1980-01-01

The results of sintered iron and of blast-furnace slag examination obtained by X-ray fluorescent analyses of energy and of wave dispersion are compared. They show that the methods are comparable for such elements as Ca and Fe, whereas for Mn (in sinter) the X-ray fluorescent analysis of wave dispersion is less precise. (author)

Chemical fingerprint of iron oxides related to iron enrichment of banded iron formation from the Cauê Formation - Esperança Deposit, Quadrilátero Ferrífero, Brazil: a laser ablation ICP-MS study

Directory of Open Access Journals (Sweden)

Lucilia Aparecida Ramos de Oliveira

Full Text Available Chemical signatures of iron oxides from dolomitic itabirite and high-grade iron ore from the Esperança deposit, located in the Quadrilátero Ferrífero, indicate that polycyclic processes involving changing of chemical and redox conditions are responsible for the iron enrichment on Cauê Formation from Minas Supergroup. Variations of Mn, Mg and Sr content in different generations of iron oxides from dolomitic itabirite, high-grade iron ore and syn-mineralization quartz-carbonate-hematite veins denote the close relationship between high-grade iron ore formation and carbonate alteration. This indicates that dolomitic itabirite is the main precursor of the iron ore in that deposit. Long-lasting percolation of hydrothermal fluids and shifts in the redox conditions have contributed to changes in the Y/Ho ratio, light/heavy rare earth elements ratio and Ce anomaly with successive iron oxide generations (martite-granular hematite, as well as lower abundance of trace elements including rare earth elements in the younger specularite generations.

The fatigue in workers of Iran Central Iron Ore Company in Yazd.

Science.gov (United States)

Halvani, Golam Hossein; Zare, Mohsen; Hobobati, Hamid

2009-01-01

To evaluate fatigue, sub-dimensions, and job satisfaction among workers of Iran Central Iron Ore Co., and obtain the relationship between them. In a cross-sectional study, fatigue and the dimensionality were measured using Iranian version of Piper Fatigue Scale questionnaire (PFS). Job satisfaction was estimated with the job satisfaction scale (JSS) as well. The score of severe fatigue in four sub-scale/dimensions and total fatigue scores were: 11.9, 15.2, 11.3, 10.8 and 10.6%, respectively. Furthermore, there was significant difference between total fatigue and all its sub-dimensions in relation to job satisfaction of workers. Fatigue has caused job dissatisfaction of participants in our study, therefore we should note that the nature of fatigue may affect the psychological aspects of industrial workforce and can be harmful for business activities.

The nature of hematite depression with corn starch in the reverse flotation of iron ore.

Science.gov (United States)

Shrimali, Kaustubh; Atluri, Venkata; Wang, Yan; Bacchuwar, Sanket; Wang, Xuming; Miller, Jan D

2018-08-15

The function of corn starch and the significance of the order of addition of corn starch and mono ether amine in the reverse flotation of iron ore has been investigated. Understanding hematite depression with starch and the corresponding hydrophilic state involves consideration of adsorption with amine as well as flocculation of fine hematite. Captive bubble contact angle and micro-flotation experiments indicated that amine has an affinity towards both hematite and quartz, and that the role of starch is to hinder the adsorption of amine at the hematite surface so that flotation is inhibited. Micro-flotation results confirmed that quartz does not have affinity towards starch at pH 10.5. In addition to competitive adsorption, flocculation of fine hematite occurs and images from high resolution X-ray computed tomography (HRXCT) and cryo-SEM reveal further detail regarding floc structure. These results provide substantial evidence that the fine hematite particles are flocculated in the presence of corn starch, and flocculation is dependent on the particle size of hematite, with greater flocculation for finer particles. Thus, starch is playing a dual role in the reverse flotation of iron ore, acting as a depressant by hindering amine adsorption at the hematite surface in order to maintain the hydrophilic surface state of hematite, and acting as a flocculant to aggregate fine hematite particles, which if not flocculated, could diminish the flotation separation efficiency by being transported to the froth phase during reverse flotation. Copyright © 2018 Elsevier Inc. All rights reserved.

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)

Preparation and characterization of novel glass–ceramic tile with microwave absorption properties from iron ore tailings

International Nuclear Information System (INIS)

Yao, Rui; Liao, SongYi; Dai, ChangLu; Liu, YuChen; Chen, XiaoYu; Zheng, Feng

2015-01-01

A novel glass–ceramic tile consisting of one glass–ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73–99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass–ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn 2+ 0.17 Fe 3+ 0.83 )[Fe 3+ 1.17 Fe 2+ 0.06 Ni 2+ 0.77 ]O 4 were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass–ceramic layer at frequency of 2–18 GHz reached peak reflection loss (RL) of −17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass–ceramic layer can meet the requirements of different level of microwave absorption. - Highlights: • Iron ore tailings (IOTs) have been used as one of the main raw materials. • Glass–ceramic tile contains spinel ferrite has been prepared. • The cation distribution of the spinel ferrite has been calculated. • The intrinsic complex permeability and permittivity have been evaluated

Immobilization of Uranium Silicides in Sintered Glass

International Nuclear Information System (INIS)

Mateos, P.; Russo, D.O.; Heredia, A.D.; Sanfilippo, M.

2003-01-01

High activity nuclear spent fuels vitrification by fusion is a well known technology which has industrial scale in France, England, Japan, EEUU. Borosilicates glasses are used in this process.Sintered glasses are an alternative to the immobilization task in which there is also a wide experience around the world.The available technics are: cold pressing and sintering , hot-pressing and hot isostatic pressing.This work compares Borosilicates and Iron silicates sintered glasses behaviour when different ammounts of nuclear simulated waste is added

Extraction of metals from ores by bacterial leaching: present status and future prospects

International Nuclear Information System (INIS)

Kelly, D.P.

1977-01-01

The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

Adsorption and removal of arsenic from water by iron ore mining waste.

Science.gov (United States)

Nguyen, Tien Vinh; Nguyen, Thi Van Trang; Pham, Tuan Linh; Vigneswaran, Saravanamuth; Ngo, Huu Hao; Kandasamy, J; Nguyen, Hong Khanh; Nguyen, Duc Tho

2009-01-01

There is a global need to develop low-cost technologies to remove arsenic from water for individual household water supply. In this study, a purified and enriched waste material (treated magnetite waste, TMW) from the Trai Cau's iron ore mine in the Thai Nguyen Province in Vietnam was examined for its capacity to remove arsenic. The treatment system was packed with TMW that consisted of 75% of ferrous-ferric oxide (Fe(3)O(4)) and had a large surface area of 89.7 m(2)/g. The experiments were conducted at a filtration rate of 0.05 m/h to treat groundwater with an arsenic concentration of 380 microg/L and iron, manganese and phosphate concentrations of 2.07 mg/L, 0.093 mg/L and 1.6 mg/L respectively. The batch experimental results show that this new material was able to absorb up to 0.74 mg arsenic/g. The results also indicated that the treatment system removed more than 90% arsenic giving an effluent with an arsenic concentration of less than 30 microg/L while achieving a removal efficiency of about 80% for Mn(2 + ) and PO(4) (3-). This could be a promising and cost-effective new material for capturing arsenic as well as other metals from groundwater.

Laser sintering of magnesia with nanoparticles of iron oxide and aluminum oxide

International Nuclear Information System (INIS)

García, L.V.; Mendivil, M.I.; Roy, T.K. Das; Castillo, G.A.; Shaji, S.

2015-01-01

Highlights: • Laser sintered MgO pellets with nanoparticles of Al 2 O 3 and Fe 2 O 3 . • Characterized these pellets by XRD, SEM and XPS. • Spinel formations were observed in both cases. • Changes in morphology and structure were analyzed. - Abstract: Nanoparticles of iron oxide (Fe 2 O 3 , 20–40 nm) and aluminum oxide (Al 2 O 3 , 50 nm) were mixed in different concentrations (3, 5 and 7 wt%) in a magnesium oxide (MgO) matrix. The mixture pellet was irradiated with 532 nm output from a Q-switched Nd:YAG laser using different laser fluence and translation speed for sintering. The refractory samples obtained were analyzed using X-ray diffraction technique, scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that the samples irradiated at translation speed of 110 μm/s and energy fluence of 1.7 J/cm 2 with a concentration of 5 and 7 wt% of Fe 2 O 3 presented the MgFe 2 O 4 spinel-type phase. With the addition of Al 2 O 3 nanoparticles, at a translation speed of 110 μm/s and energy fluence of 1.7 J/cm 2 , there were the formations of MgAl 2 O 4 spinel phase. The changes in morphologies and microstructure due to laser irradiation were analyzed

Hydrometallurgical Processing Technology of Titanomagnetite Ores

Directory of Open Access Journals (Sweden)

Victor Ivanovich Sachkov

2017-12-01

Full Text Available In this paper, we study the possibility of obtaining iron and titanium-vanadium concentrates with highest contents of iron and titanium, respectively, through hydrometallurgical processing of the titanomagnetite ores of the Chineisk deposit. We varied two key parameters to determine the efficiency of the process: (a concentration of leaching solution (ammonium fluoride; and (b acidity of solution. Ammonium fluoride concentration was varied from 0.08 mol/L to 4.2 mol/L with the other fixed parameters. It was shown that optimum ammonium fluoride concentration for leaching the ore is 0.42 mol/L; at these concentrations iron and titanium contents are about 62.8 wt % and 3.5 wt % in solid phase, respectively. The acidity of solution was changed by adding of hydrofluoric acid with varied concentration (from 0.86 mol/L to 4.07 mol/L to ammonium fluoride solution with fixed concentration of 0.42 mol/L. The best results (degree of titanium extraction = 63.7% were obtained when using a solution of hydrofluoric acid with concentration 4.07 mol/L. In this case, the addition of acid makes it possible to increase the Fe/Ti ratio by 3.4 times in comparison with the original ore. Thus, we conclude that acidity and the concentration of ammonium fluoride solution significantly influences the selectivity of the hydrometallurgical process.

Effects of Ore dust pollution on the physical and chemical features ...

African Journals Online (AJOL)

Effects of wind-blown iron and manganese ore dust on the upper part of a sandy beach have been investigated. The fine ore dust was found to reduce the porosity and permeability of the sand by clogging the interstices. The presence of ore dust also greatly increased the rate of heating and cooling of beach sand. Further ...

Mineralogy and electron microprobe studies of magnetite in the Sarab-3 iron Ore deposit, southwest of the Shahrak mining region (east Takab

Directory of Open Access Journals (Sweden)

Mohammad Maanijou

2018-04-01

Full Text Available Introduction There is an iron mining complex called Shahrak 60 km east of the Takab town, NW Iran. The exploration in the Shahrak deposit (general name for all iron deposits of the area started in 1992 by the Foolad Saba Noor Co. and continued in several periods until 2008. The Shahrak deposit is comprised of 10 ore deposits including Sarab-1, Sarab-2, Sarab-3, Korkora-1, Korkora-2, Shahrak-1, Shahrak-2, Shahrak-3, Cheshmeh and Golezar deposits (Sheikhi, 1995 with a total 60 million tons of proven ore reserves. The Fe grade ranges from 45 to 65% (average 50%. The ore reserves of these deposits are different. Sarab-3 ore deposit with 9 million tons of 54% Fe and 8.95% S is located at the northeast of Kurdistan and in the Sanandaj-Sirjan structural zone at the latitude of 36°20´ and longitude of 47°32´. Materials and methods Sixty thin-polished, polished and thin sections are made for the study of mineralogy and petrology, and among them six thin-polished sections were selected for EPMA (Electron Probe Micro Analysis on magnetite and hematite. EPMA was performed using the Cameca Sx100 electron microprobe at the Iran Mineral Processing Research Center (IMPRC with wavelength-dispersive spectrometers. Results and discussion Based on field observations and petrographic studies, lithologic composition of intrusion (Miocene age ranges within the diorite-leucodiorite, monzodiorite-quartz monzodiorite, granodiorite-granite. With the intrusion of those igneous bodies into carbonate rocks of the Qom Formation, contact metamorphism was formed. The formation of Sarab-3 iron deposit occurred at the three stages of metamorphism, skarnification and supergene. Based on field geology of the deposit, it is composed of endoskarn, exoskarn including Fe ore±sulfides. At the metamorphic stage, after intrusion of intrusive bodies in carbonate rocks, recrystallization took place and marble was formed. With more crystallization of magma, evolved hydrothermal fluids

Evaluation of thermal properties of sintered beryllium oxide produced from Indian beryl ore

International Nuclear Information System (INIS)

Nair, Sathi R.; Ghanwat, S.J.; Patro, P.K.; Syambabu, M.; Mawal, N.E.; Mahata, T.; Sinha, P.K.

2014-01-01

Beryllium oxide (BeO) ceramics possess many interesting properties such as good thermal conductivity, high electrical resistivity, high chemical and thermal stability, low dielectric constant, low dielectric loss and low neutron absorption coefficient. These properties lead to its wide use in vacuum electronics technology, nuclear technology, microelectronics and photoelectron technology. The above properties depend on the purity of the material as well as density and microstructure of the sintered body. For high temperature application thermal conductivity and thermal expansion are two important parameters. In the present study, high purity fine BeO powder has been prepared by beryllate route starting with crude beryllium hydroxide. The powder has been sintered at 1550℃ and sintered samples have been evaluated for its thermal properties

Moessbauer and XRD Comparative Study of Host Rock and Iron Rich Mineral Samples from Paz del Rio Iron Ore Mineral Mine in Colombia

International Nuclear Information System (INIS)

Fajardo, M.; Perez Alcazar, G. A.; Moreira, A. M.; Speziali, N. L.

2004-01-01

A comparative study between the host rock and the iron rich mineral samples from the Paz del Rio iron ore mineral mine in Colombia was performed using X-ray diffraction and Moessbauer spectroscopy. Diffraction results of the iron rich mineral sample show that goethite, hematite, quartz, kaolinite and siderite are the main phases, and that a small amount of illite is also present. By Moessbauer spectroscopy at room temperature (RT) the presence of all the above mentioned phases was detected except quartz as well as an additional presence of small amount of biotite. The goethite, which appears as four sextets with hyperfine fields of 33.5, 30.5, 27.5 and 18.5 T, respectively, is the majority phase. This result shows the different grades of formation of this oxyhydroxide. The Moessbauer spectrum of this sample at 80 K presents the same phases obtained at RT without any superparamagnetic effect. In this case the goethite appears as two sextets. Diffraction results of the host rock sample show a large amount of quartz and kaolinite and small amounts of illite and biotite, whereas by Moessbauer spectroscopy illite, kaolinite and biotite were detected.

Preparation and characterization of novel glass–ceramic tile with microwave absorption properties from iron ore tailings

Energy Technology Data Exchange (ETDEWEB)

Yao, Rui; Liao, SongYi [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Dai, ChangLu [Guangdong Bode Fine Building Material Co. Ltd., Foshan 528000 (China); Liu, YuChen; Chen, XiaoYu [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Zheng, Feng, E-mail: fzheng@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Phase diagrams and materials design center, Central South University, Changsha 410083 (China)

2015-03-15

A novel glass–ceramic tile consisting of one glass–ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73–99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass–ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn{sup 2+}{sub 0.17}Fe{sup 3+}{sub 0.83})[Fe{sup 3+}{sub 1.17}Fe{sup 2+}{sub 0.06}Ni{sup 2+}{sub 0.77}]O{sub 4} were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass–ceramic layer at frequency of 2–18 GHz reached peak reflection loss (RL) of −17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass–ceramic layer can meet the requirements of different level of microwave absorption. - Highlights: • Iron ore tailings (IOTs) have been used as one of the main raw materials. • Glass–ceramic tile contains spinel ferrite has been prepared. • The cation distribution of the spinel ferrite has been calculated. • The intrinsic complex permeability and permittivity have been evaluated.

Nano-Structured Magnesium Oxide Coated Iron Ore: Its Application to the Remediation of Wastewater Containing Lead.

Science.gov (United States)

Nagarajah, Ranjini; Jang, Min; Pichiah, Saravanan; Cho, Jongman; Snyder, Shane A

2015-12-01

Magnetically separable nano-structured magnesium oxide coated iron ore (IO(MgO)) was prepared using environmentally benign chemicals, such as iron ore (IO), magnesium(II) nitrate hexahydrate [Mg(NO3)2 x 6H2O] and urea; via an easy and fast preparation method. The lO(MgO) was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and alternating gradient magnetometer (AGM) analyses. The isotherm and kinetic studies indicated that lO(MgO) has a comparably higher Langmuir constant (K(L), 1.69 L mg(-1)) and maximum sorption capacity (33.9 mg g(-1)) for lead (Pb) than other inorganic media. Based on MgO amount, the removal capacity of Pb by IO(MgO) was 2,724 mg Pb (g MgO)(-1), which was higher than that (1,980 mg g(-1)) for flowerlike magnesium oxide nanostructures reported by Cao et al. The kinetics, FE-SEM, elemental mapping and XRD results revealed that the substitution followed by precipitation was identified as the mechanism of Pb removal and plumbophyllite (Pb2Si4O10 x H2O) was the precipitated phase of Pb. A leaching test revealed that IOMgO) had negligible concentrations of leached Fe at pH 4-9. Since the base material, IO, is cheap and easily available, lO(MgO) could be produced in massive amounts and used for remediation of wastewater containing heavy metals, applying simple and fast magnetic separation.

Detection and mapping of the iron ore occurrence in the sea floor sediments in the coastal zone of the Sepetiba Bay. Rio de Janeiro. Brasil

International Nuclear Information System (INIS)

Vieira, P.

2010-01-01

This work is about the detection and mapping of the iron occurrence in the sea floor sediments in the coastal zone of the Sepetiba Bay. Rio de Janeiro. Brasil. The results of geochemical analysis revealed that the area around the mangrove forest located near the Itacuruca channel, the perpendicular direction to the Muriqui Yacht Club channel and the immediate vicinity of the the Guaiba Island Terminal were respectively the areas of highest iron ore concentration

Laser sintering of magnesia with nanoparticles of iron oxide and aluminum oxide

Energy Technology Data Exchange (ETDEWEB)

García, L.V.; Mendivil, M.I.; Roy, T.K. Das; Castillo, G.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66451 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66451 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

2015-05-01

Highlights: • Laser sintered MgO pellets with nanoparticles of Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3}. • Characterized these pellets by XRD, SEM and XPS. • Spinel formations were observed in both cases. • Changes in morphology and structure were analyzed. - Abstract: Nanoparticles of iron oxide (Fe{sub 2}O{sub 3}, 20–40 nm) and aluminum oxide (Al{sub 2}O{sub 3}, 50 nm) were mixed in different concentrations (3, 5 and 7 wt%) in a magnesium oxide (MgO) matrix. The mixture pellet was irradiated with 532 nm output from a Q-switched Nd:YAG laser using different laser fluence and translation speed for sintering. The refractory samples obtained were analyzed using X-ray diffraction technique, scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that the samples irradiated at translation speed of 110 μm/s and energy fluence of 1.7 J/cm{sup 2} with a concentration of 5 and 7 wt% of Fe{sub 2}O{sub 3} presented the MgFe{sub 2}O{sub 4} spinel-type phase. With the addition of Al{sub 2}O{sub 3} nanoparticles, at a translation speed of 110 μm/s and energy fluence of 1.7 J/cm{sup 2}, there were the formations of MgAl{sub 2}O{sub 4} spinel phase. The changes in morphologies and microstructure due to laser irradiation were analyzed.

Distribution and Multivariate Pollution Risks Assessment of Heavy Metals and Natural Radionuclides Around Abandoned Iron-Ore Mines in North Central Nigeria

Science.gov (United States)

Isinkaye, Omoniyi Matthew

2018-02-01

The Itakpe abandoned iron-ore mines constitute the largest iron-ore deposits in Nigeria with an estimated reserve of about three million metric tons of ore. The present effort is a part of a comprehensive study to estimate the environmental and radiological health hazards associated with previous mining operations in the study area. In this regard, heavy metals (Fe, Zn, Cu, Cd, Cr, Mn, Pb, Ni, Co and As) and natural radionuclides (U, Th and K) were measured in rock, soil and water samples collected at different locations within the mining sites. Atomic absorption and gamma-ray spectrometry were utilized for the measurements. Fe, Mn, Zn, Cu, Ni, Cd, Cr, Co Pb and As were detected at varying concentrations in rock and soil samples. Cd, Cr, Pb and As were not detected in water samples. The concentrations of heavy metals vary according to the following pattern; rock ˃ soil ˃ water. The mean elemental concentrations of K, U and Th are 2.9%, 0.8 and 1.2 ppm and 1.3%, 0.7 and 1.7 ppm, respectively, for rock and soil samples. Pearson correlation analyses of the results indicate that the heavy metals are mostly negatively correlated with natural radionuclides in the study area. Cancer and non-cancer risks due to heavy metals and radiological hazards due to natural radionuclides to the population living within the vicinity of the abandoned mines are lower than acceptable limits. It can, therefore, be concluded that no significant environmental or radiological health hazard is envisaged.

Silicophosphate Sorbents, Based on Ore-Processing Plants' Waste in Kazakhstan

Science.gov (United States)

Kubekova, Sholpan N.; Kapralova, Viktoria I.; Telkov, Shamil A.

2016-01-01

The problem of ore-processing plants' waste and man-made mineral formations (MMF) disposal is very important for the Republic of Kazakhstan. The research of various ore types (gold, polymetallic, iron-bearing) MMF from a number of Kazakhstan's deposits using a complex physical and chemical methods showed, that the waste's main components are…

Determination of the oxidizing capacity of manganese ores.

Science.gov (United States)

Prasad, R

1974-09-01

An accurate method is described for determining the amount of active oxygen in manganese ores, based on the oxidation-reduction reaction between the ore and arsenic(III) in presence of ammonium molybdate, followed by the back-titration of excess of arsenic(III) with cerium(IV), using osmium tetroxide as catalyst and Disulphine Blue V as indicator. A survey has been made of the applicability of this method to various pyrolusite ores containing less than 0.2% phosphorus. Aluminium(III), copper(II), iron(III), manganese(II), and molybdenum(VI) do not interfere. Up to 30% phosphorus(V) causes no interference.

Arsenic enrichment in estuarine sediments-impact of iron and manganese mining

Digital Repository Service at National Institute of Oceanography (India)

Nair, M.; Joseph, T.; Balachandran, K.K.; Nair, K.K.C.; Paimpillii, J.S.

River Mandovi and Zuari, Goa (west coast of India) are flowing through iron and manganese mining areas and are heavily used for iron and manganese ore transport. This region generates 25-30 million tons of mining rejects per year. The iron ore...

The evaluation of different environments in ultra-high frequency induction sintered powder metal compacts

International Nuclear Information System (INIS)

Cavdar, P. S.; Cavdar, U.

2015-01-01

The application of the iron based Powder Metal (PM) compacts in Ultra-High Frequency Induction Sintering (UHFIS) was reviewed for different environments. The three different environments: atmosphere, argon and vacuum were applied to the PM compacts. Iron based PM compacts were sintered at 1120 degree centigrade for a total of 550 seconds by using induction sintering machines with 2.8 kW power and 900 kHz frequency. Micro structural properties, densities, roughness and micro hardness values were obtained for all environments. The results were compared with each other. (Author)

Optimization of flotation variables for the recovery of hematite particles from BHQ ore

Science.gov (United States)

Rath, Swagat S.; Sahoo, Hrushikesh; Das, B.

2013-07-01

The technology for beneficiation of banded iron ores containing low iron value is a challenging task due to increasing demand of quality iron ore in India. A flotation process has been developed to treat one such ore, namely banded hematite quartzite (BHQ) containing 41.8wt% Fe and 41.5wt% SiO2, by using oleic acid, methyl isobutyl carbinol (MIBC), and sodium silicate as the collector, frother, and dispersant, respectively. The relative effects of these variables have been evaluated in half-normal plots and Pareto charts using central composite rotatable design. A quadratic response model has been developed for both Fe grade and recovery and optimized within the experimental range. The optimum reagent dosages are found to be as follows: collector concentration of 243.58 g/t, dispersant concentration of 195.67 g/t, pH 8.69, and conditioning time of 4.8 min to achieve the maximum Fe grade of 64.25% with 67.33% recovery. The predictions of the model with regard to iron grade and recovery are in good agreement with the experimental results.

The development of microstructure during hydrogenation–disproportionation–desorption–recombination treatment of sintered neodymium-iron-boron-type magnets

International Nuclear Information System (INIS)

Sheridan, R.S.; Harris, I.R.; Walton, A.

2016-01-01

The hydrogen absorption and desorption characteristics of the hydrogenation disproportionation desorption and recombination (HDDR) process on scrap sintered neodymium-iron-boron (NdFeB) type magnets have been investigated. At each stage of the process, the microstructural changes have been studied using high resolution scanning electron microscopy. It was found that the disproportionation reaction initiates at grain boundaries and triple points and then propagates towards the centre of the matrix grains. This process was accelerated at particle surfaces and at free surfaces produced by any cracks in the powder particles. However, the recombination reaction appeared to initiate randomly throughout the particles with no apparent preference for particle surfaces or internal cracks. During the hydrogenation of the grain boundaries and triple junctions, the disproportionation reaction was, however, affected by the much higher oxygen content of the sintered NdFeB compared with that of the as-cast NdFeB alloys. Throughout the entire HDDR reaction the oxidised triple junctions (from the sintered structure) remained unreacted and hence, remained in their original form in the fine recombined microstructure. This resulted in a very significant reduction in the proportion of cavitation in the final microstructure and this could lend to improved consolidation in the recycled magnets. - Highlights: • Disproportionation reaction initiates at grain boundaries and triple points. • Disproportionation then propagates towards the centre of the matrix grains. • Disproportionation was affected by the high oxygen content of sintered NdFeB. • Oxidised triple points remain unreacted in original form in final HDDR structure. • Significant reduction in the proportion of cavitation in the final microstructure.

The development of microstructure during hydrogenation–disproportionation–desorption–recombination treatment of sintered neodymium-iron-boron-type magnets

Energy Technology Data Exchange (ETDEWEB)

Sheridan, R.S.; Harris, I.R.; Walton, A., E-mail: a.walton@bham.ac.uk

2016-03-01

The hydrogen absorption and desorption characteristics of the hydrogenation disproportionation desorption and recombination (HDDR) process on scrap sintered neodymium-iron-boron (NdFeB) type magnets have been investigated. At each stage of the process, the microstructural changes have been studied using high resolution scanning electron microscopy. It was found that the disproportionation reaction initiates at grain boundaries and triple points and then propagates towards the centre of the matrix grains. This process was accelerated at particle surfaces and at free surfaces produced by any cracks in the powder particles. However, the recombination reaction appeared to initiate randomly throughout the particles with no apparent preference for particle surfaces or internal cracks. During the hydrogenation of the grain boundaries and triple junctions, the disproportionation reaction was, however, affected by the much higher oxygen content of the sintered NdFeB compared with that of the as-cast NdFeB alloys. Throughout the entire HDDR reaction the oxidised triple junctions (from the sintered structure) remained unreacted and hence, remained in their original form in the fine recombined microstructure. This resulted in a very significant reduction in the proportion of cavitation in the final microstructure and this could lend to improved consolidation in the recycled magnets. - Highlights: • Disproportionation reaction initiates at grain boundaries and triple points. • Disproportionation then propagates towards the centre of the matrix grains. • Disproportionation was affected by the high oxygen content of sintered NdFeB. • Oxidised triple points remain unreacted in original form in final HDDR structure. • Significant reduction in the proportion of cavitation in the final microstructure.

The Balance of Titanium and Vanadium in the Blast Furnace with the Use of Sinter Containing a Titanium-Vanadium-Magnetite Concentrate

Directory of Open Access Journals (Sweden)

Budzik, R.

2007-01-01

Full Text Available The investigation concerned the use of sinter containing a titanium-vanadium-magnetite concentrate for the production of pig iron. Sinter containing 0,46 to 0,51 % TiO2 and 0,056 to 0,060 % vanadium was used for pig iron production in the blast furnace. Introducing 200 kg of this concentrate to the1 Mg sinter mix did not cause any deterioration of sinter quality.

Composition suitable as collection agent in ore flotation process and preparation of said composition

International Nuclear Information System (INIS)

Bresson, C.R.; Parlman, R.M.

1984-01-01

A composition and process are provided for the recovery of the values of zinc, molybdenum, copper, lead, ion (pyrite), and iron-containing small amounts of gold or uranium, or both, from ores comprising these mineral sulfides. The aqueous composition is the impure form of an alkali metal alkyl trithiocarbonate compound. The process comprises employing said aqueous composition as a collection agent for the above minerals in an ore recovery process. A process for the separation of zinc values from lead values from an ore comprising both is provided by employing an alkali metal alkyl trithiocarbonate compound as a collection agent for zinc. In addition, both a composition and process are provided for the recovery of the values of iron, copper, and lead from ores comprising these values. The composition consists essentially of a dispersant and an impure form of an alkali metal alkyl trithiocarbonate compound. The process comprises employing this composition as a collection agent for the above minerals in an ore recovery process

ALTERNATIVE BINDERS TO BENTONITE FOR IRON ORE PELLETIZING : PART II : EFFECTS ON METALLURGICAL AND CHEMICAL PROPERTIES

Directory of Open Access Journals (Sweden)

Osman Sivrikaya

2014-07-01

Full Text Available This study was started to find alternative binders to bentonite and to recover the low preheated and fired pellet mechanical strengths of organic binders-bonded pellets. Bentonite is considered as a chemical impurity for pellet chemistry due to acid constituents (SiO2 and Al2O3. Especially addition of silica-alumina bearing binders is detrimental for iron ore concentrate with high acidic content. Organic binders are the most studied binders since they are free in silica. Although they yield pellets with good wet strength; they have found limited application in industry since they fail to give sufficient physical and mechanical strength to preheated and fired pellets. It is investigated that how insufficient preheated and fired pellet strengths can be improved when organic binders are used as binder. The addition of a slag bonding/strength increasing constituent (free in acidic contents into pellet feed to provide pellet strength with the use of organic binders was proposed. Addition of boron compounds such as colemanite, tincal, borax pentahydrate, boric acid together with organic binders such as CMC, starch, dextrin and some organic based binders, into magnetite and hematite pellet mixture was tested. After determining the addition of boron compounds is beneficial to recover the low pellet physical and mechanical qualities in the first part of this study, in this second part, metallurgical and chemical properties (reducibility - swelling index – microstructure – mineralogy - chemical content of pellets produced with combined binders (an organic binder plus a boron compound were presented. The metallurgical and chemical tests results showed that good quality product pellets can be produced with combined binders when compared with the bentonite-bonded pellets. Hence, the suggested combined binders can be used as binder in place of bentonite in iron ore pelletizing without compromising the pellet chemistry.

Study on the pre-treatment of oxidized zinc ore prior to flotation

Science.gov (United States)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

Magnetodielectric coupling in multiferroic holmium iron garnets

International Nuclear Information System (INIS)

Malar Selvi, M.; Chakraborty, Deepannita; Venkateswaran, C.

2017-01-01

Single phase magneto-electric multiferroics require a large magnetic or electric field for producing magneto-electric (ME) and magnetodielectric (MD) effects. For utilizing these effects in devices investigations on the room temperature and low field MD studies are necessary. Recently, efforts have been largely devoted to the investigation of rare earth iron garnets. In the physical method, the preparation of rare earth iron garnet requires high sintering temperature and processing time. To solve these problems, ball milling assisted microwave sintering technique is used to prepare nanocrystalline holmium iron garnets (Ho_3Fe_5O_1_2). Magnetic and dielectric properties of the prepared sample are investigated. These properties get enhanced in nanocrystalline form when compared to the bulk. The MD coupling of the prepared sample is evident from the anomaly in the temperature dependent dielectric constant plot and the ME coupling susceptibility is derived from the room temperature MD measurements. - Highlights: • Formation of single phase Holmium iron garnet reported. • Ball milling assisted microwave sintering reduces the sintering temperature and time. • Holmium iron garnet shows enhanced magnetic and dielectric properties. • Pyromagnetic and pyroelectric measurements confirm the magnetoelectric coupling. • Room temperature magnetodielectric measurements show the nonlinear behaviour.

Dissolution of copper, tin, and iron from sintered tungsten-bronze spheres in a simulated avian gizzard, and an assessment of their potential toxicity to birds

International Nuclear Information System (INIS)

Thomas, Vernon G.; McGill, Ian R.

2008-01-01

The rates of dissolution of copper, tin, and iron from sintered tungsten-bronze spheres (51.1%W, 44.4%Cu, 3.9%Sn, 0.6%Fe, by mass) were measured in an in vitro simulated avian gizzard at pH 2.0, and 42C. Most of the spheres had disintegrated completely to a fine powder by day 14. Dissolution of copper, tin, and iron from the spheres was linear over time; all r > 0.974; all P < 0.001. The mean rate of release of copper, tin, and iron was 30.4 mg, 2.74 mg, and 0.38 mg per g tungsten-bronze per day, respectively. These rates of metal release were compared to those in published studies to determine whether the simultaneous ingestion of eight spheres of 3.48 mm diameter would pose a toxic risk to birds. The potential absorption rates of iron and tin (0.54 mg Fe/day, and 3.89 mg Sn/day) from eight tungsten-bronze spheres of total mass 1.42 g would not prove toxic, based on empirical studies of tin and iron ingestion in waterfowl. The release of 43.17 mg copper/day from eight tungsten-bronze spheres, while exceeding the daily copper requirements of domesticated birds, is far below the levels of copper known to cause copper toxicosis in birds. We conclude that sintered tungsten-bronze material made into gunshot, fishing weights, or wheel balance weights, would not pose a toxic risk to wild birds when ingested

Commercial development of a new process of uraniferous ore sintering by pelletizing before dump leaching (wet process) application to a very clayey ore of Nord-Aquitaine

International Nuclear Information System (INIS)

Videau, G.; Roche, M.

1990-01-01

Much of the French uranium ore contains clay of sedimentary origin or derived from the alteration of rocks of the granite type. During a dump leaching operation by a wet process, these clays reduce the percolation rates and sometimes the percolation rates are so low that the very essence of the dump leaching operation can be called in question. This problem arises particularly for the treatment of the ore of Nord-Aquitaine. The results of tests, carried out at the SEPA in Bessines, have shown that after pelletizing clayey ores with sodium silicate in the presence of sulphuric acid for the polymerization of the silicate, the percolation rates were much increased. This new method was successfully applied, from a laboratory column to a pilot dump of 500 tonnes for the very clayey ore of Nord-Aquitaine. This ore of low grade (approx. 1000 ppm of U) seems to be difficult to upgrade by any other method of treatment in the present economic context [fr

Preliminary investigation of liquid phase sintering in ferrous systems

International Nuclear Information System (INIS)

Klein, J.

1975-04-01

Liquid phase sintering was utilized to achieve, by a simple compaction and sintering procedure involving short times and moderate temperatures, a virtually full dense high carbon Fe:C alloy and high boron Fe:B alloy. Parameters such as powder characteristics and mixing, compacting pressure, heating program and the liquid phase fraction were found to influence the sintered density. The response of the Fe:C alloy to a heat treatment is reported along with preliminary experiments in the iron base ternary system Fe:W:C. Residual porosities observed in microstructures of certain liquid phase sintered compacts were accounted for by a proposed capillary flow of the liquid phase and a local densification competing against an overall densification. Some general recommendations are made for liquid phase sintering of powder aggregates. 15 fig., 7 tables

Phase identification and morphology study of hematite (Fe2O3) with sintering time varitions

Science.gov (United States)

Yazirin, Cepi; Puspitasari, Poppy; Sasongko, Muhammad Ilman Nur; Tsamroh, Dewi Izzatus; Risdanareni, Puput

2017-09-01

Iron oxide has been the interest of many studies due to its applications in various scientific and industrial fields including in environment, corrosion, soil science, and exhaust emissions. Iron oxide (Fe2O3) has potential applications in catalytic reactions in electronic devices such as semiconductors, paint formulations, and lithium rechargeable batteries. Fe2O3 can be synthesized through the process of stirring, decomposition of organic iron, sol-gel, combustion, and evaporating solvents. Most of the methods used involve several steps and take a long time. The aim of this research was to investigate the phase and morphology characterization of iron oxide (Fe2O3) powder with solvent ethylene glycol after being sintered for 1 hour, 2 hours and 3 hours. The characterization tools utilized were XRD, SEM-EDX, and FTIR. The results of XRD analysis showed that the Fe2O3 sintered for 1 hour had the smallest crystallite size with a diameter of 21.05 nm. In the XRD test, the beam of X-ray was shot directly at the grain being tested. The results of SEM analysis showed thatthe Fe2O3 sintered for 1 hour produced the best result due to its crystallite size of 12.36 nm and hada shape of homogeneous nanosphere; the duration of sintering indeed had a great influence on the grain size of iron oxide (Fe2O3). In addition, the results of the elemental composition analysis indicate that the longer the sintering process, the higher the concentration of O but the lower the Fe.

Molybdenum extraction from copper-molybdenum ores

International Nuclear Information System (INIS)

Nevaeva, L.M.

1982-01-01

Molybdenum extraction from copper-molybdenum ores as practised in different countries is reviewed. In world practice the production process including depression of copper and iron sulfides and flotation of molybdenite is widely spread. At two USA factories the process of a selective flotation with molybdenite depression by dextrin is used

Compositional variation of glauconites in Upper Cretaceous-Paleogene sedimentary iron-ore deposits in South-eastern Western Siberia

Science.gov (United States)

Rudmin, Maxim; Banerjee, Santanu; Mazurov, Aleksey

2017-06-01

Glauconite occurs either as unaltered greenish or as altered brownish variety in Upper Cretaceous-Palaeocene sediments in the southeastern corner of Western Siberia. Studied section within the Bakchar iron-ore deposit includes Ipatovo, Slavgorod, Gan'kino and Lyulinvor formations, which are represented by sandstones, siltstones, claystones and oolitic ironstones of coastal-marine facies. The origin of unaltered glauconite is explained by the ;verdissement theory;. Transgressions during Lower Coniacian, Santonian and Campanian favored the formation of unaltered glauconites in dysoxic to anoxic conditions. Subaerial exposure of glauconite resulted in leaching of potassium, oxidation of iron and formation of iron hydroxides in Upper Coniacian, Maastrichtian and Palaeocene. Glauconite ultimately converts to leptochlorite and hydrogoethite by this alteration. Abundant microscopic gold inclusions, besides sulphides, sulphates, oxides and silicates characterize this glauconite. Mineral inclusions include precious, rare metals and non-ferrous metals. The concentration of gold in glauconite may be as high as 42.9 ppb. Abundant inclusions of various compositions in glauconites indicate enrichment of marine sediments in precious and non-precious metals. While major element composition of glauconites is affected by subaerial exposure, the broadly similar micro-inclusions in both altered and unaltered varieties are possibly related to the comparatively immobile nature of REE and trace elements.

Magnetization curves of sintered heavy tungsten alloys for applications in MRI-guided radiotherapy

International Nuclear Information System (INIS)

Kolling, Stefan; Oborn, Bradley M.; Keall, Paul J.; Horvat, Joseph

2014-01-01

Purpose: Due to the current interest in MRI-guided radiotherapy, the magnetic properties of the materials commonly used in radiotherapy are becoming increasingly important. In this paper, measurement results for the magnetization (BH) curves of a range of sintered heavy tungsten alloys used in radiation shielding and collimation are presented. Methods: Sintered heavy tungsten alloys typically contain >90 % tungsten and 0 and the BH curve derived. Results: The iron content of the alloys was found to play a dominant role, directly influencing the magnetizationM and thus the nonlinearity of the BH curve. Generally, the saturation magnetization increased with increasing iron content of the alloy. Furthermore, no measurable magnetization was found for all alloys without iron content, despite containing up to 6% of nickel. For two samples from different manufacturers but with identical quoted nominal elemental composition (95% W, 3.5% Ni, 1.5% Fe), a relative difference in the magnetization of 11%–16% was measured. Conclusions: The measured curves show that the magnetic properties of sintered heavy tungsten alloys strongly depend on the iron content, whereas the addition of nickel in the absence of iron led to no measurable effect. Since a difference in the BH curves for two samples with identical quoted nominal composition from different manufacturers was observed, measuring of the BH curve for each individual batch of heavy tungsten alloys is advisable whenever accurate knowledge of the magnetic properties is crucial. The obtained BH curves can be used in FEM simulations to predict the magnetic impact of sintered heavy tungsten alloys

Maps of Fe-Al phases formation kinetics parameters during isothermal sintering

Energy Technology Data Exchange (ETDEWEB)

Pochec, Ewelina, E-mail: epochec@wat.edu.pl [Department of Advanced Materials and Technology, Military University of Technology (Poland); Jozwiak, Stanislaw; Karczewski, Krzysztof; Bojar, Zbigniew [Department of Advanced Materials and Technology, Military University of Technology (Poland)

2012-10-10

Highlights: Black-Right-Pointing-Pointer The sintering temperature and compaction pressure have a strong influence on the sinters structure. Black-Right-Pointing-Pointer The measurements confirmed the presence of the high-aluminium phases from Fe-Al equilibrium system in tested sinters. Black-Right-Pointing-Pointer The kinetics of Fe-Al phase formation can be described by Johnson-Mehl-Avrami modelling. - Abstract: The influence of technological parameters (compaction pressure and sintering temperature) on Fe-Al phase formation was investigated. The kinetics of phase transformation preceding and during an SHS reaction was studied in isothermal conditions by DSC using the JMA (Johnson-Mehl-Avrami) model. This model allowed us to determine basic kinetic parameters, including the Avrami exponent, which characterises the rate and manner of particular phase nucleation. The activation energy (E{sub a}) of particular phase formation was determined by the Kissinger method. XRD analysis and SEM observations of sintered material showed that not only Fe{sub 2}Al{sub 5} phase and low-aluminium solid solution in iron but also aluminium-rich FeAl{sub 2} and FeAl{sub 3} phases are formed during the sintering of an FeAl50 elementary powder mixture in isothermal conditions with an SHS reaction. The above conclusions were confirmed by iron-based solid solution lattice parameter studies and microhardness measurements.

Chlorination of uranium ore for extraction of uranium, thorium and radium and for pyrite removal

International Nuclear Information System (INIS)

Skeaf, J.M.

1979-01-01

The high-temperature chlorination of uranium ore was investigated. The objective was to develop a process which is both economically viable and environmentally acceptable. Test work was directed toward obtaining high extractions of uranium, thorium and radium-226, as well as iron, sulphur and the rare earths, and consists of chlorinating samples of an Elliot Lake uranium ore at elevated temperatures and repulping the resulting calcine in dilute hydrochloric acid. The effect of temperature and chlorine throughput on the extraction of the various metals was investigated. The best conditions yielded extractions of uranium, iron and sulphur (all as chlorides) greater than 95 percent. Chlorine consumption varied between 6 and 16 percent by weight of the ore charge. (author)

Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud

International Nuclear Information System (INIS)

He, Hongtao; Yue, Qinyan; Su, Yuan; Gao, Baoyu; Gao, Yue; Wang, Jingzhou; Yu, Hui

2012-01-01

Highlights: ► The best condition was red mud content of 40% and sintering at 1050 °C for 2 h. ► Bricks’ weight loss was caused by the removal of absorbed water and crystal water. ► Bricks’ sintering shrinkage depended on the sodium and iron compounds of red mud. ► Sintering can strengthen bricks and decrease leaching concentration of toxic metal. - Abstract: The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050 °C and sintering time of 2 h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards.

Spent fuel from nuclear research reactors immobilized in sintered glass

International Nuclear Information System (INIS)

Mateos, P.; Russo, D.O.; Rodriguez, D.; Heredia, A.; Sanfilippo, M.; Sterba, M.

2002-01-01

Different kinds of glasses, borosilicates, Iron borosilicates and Iron phosphates, were tested in order to determine its capability to immobilize calcined uranium silicide in a sintering process. Iron phosphate glass developed in our laboratory showed the best results in SEM analysis. Also its gravimetric leaching rate is less than 0.45 g.m -2 .day -1 for 7 and 10% loading which is lower than any previously studied for us. (author)

Microstructure and properties of multiphase sintered cermets Fe-Fe{sub 2}B; Mikrostruktura i wlasnosci spiekanych reakcyjnie cermetali Fe-Fe{sub 2}B

Energy Technology Data Exchange (ETDEWEB)

Nowacki, J. [Wydzial Inzynierii Materialowej, Politechnika Szczecinska, Szczecin (Poland); Klimek, L. [Instytut Inzynierii Materialowej i Technik Bezwiorowych, Politechnika Lodzka, Lodz (Poland)

1998-12-31

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe{sub 2}B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe{sub 2}B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe{sub 2}B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe{sub 2}B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe{sub 2}B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe{sub 2}B cermets are a composite material in which iron boride, Fe{sub 2}B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe{sub 2}B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe{sub 2}B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above

Introduction - Acid decomposition of borosilicate ores

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

Application of nonisothermal kinetic techniques on the reduction of three commercial iron ore agglomerates

International Nuclear Information System (INIS)

Bedolla, E.; Leon, C.A.; Aguilar, E.A.

1997-01-01

The mechanism of reduction of iron ore agglomerates by both isothermal and nonisothermal TG studies was investigated, and the work was complemented with the structural characterization of the total and partially reacted samples. Three different commercial hematite pellets were studied. The mechanisms of reduction were obtained under isothermal conditions, resulting in a fitting to chemical reaction models. Nonisothermal reduction was carried out using a TGA system (CAHN TG-171) from 600 to 1,000 degree centigree maintaining a lineal heating rate of 4,7 and 10 degree centigree/min, and the reducing atmospheres used were H 2 (100%) and H 2 -CO(95:5). The kinetic parameters were evaluated by Coats and Redfern, Dixit and Ray and Prakash and Ray techniques. It was found that the lower the heating rate, the higher the reduction degree and the higher activation energy. The activation energy for reduction with the mixture H 2 -CO was always higher than that obtained with pure H 2 . (Author)

Hydrogeochemical assessment of mine-impacted water and sediment of iron ore mining

Science.gov (United States)

Nur Atirah Affandi, Fatin; Kusin, Faradiella Mohd; Aqilah Sulong, Nur; Madzin, Zafira

2018-04-01

This study was carried out to evaluate the hydrogeochemical behaviour of mine-impacted water and sediment of a former iron ore mining area. Sampling of mine water and sediment were carried out at selected locations within the mine including the former mining ponds, mine tailings and the nearby stream. The water samples were analysed for their hydrochemical facies, major and trace elements including heavy metals. The water in the mining ponds and the mine tailings was characterised as highly acidic (pH 2.54-3.07), but has near-neutral pH in the nearby stream. Results indicated that Fe and Mn in water have exceeded the recommended guidelines values and was also supported by the results of geochemical modelling. The results also indicated that sediments in the mining area were contaminated with Cd and As as shown by the potential ecological risk index values. The total risk index of heavy metals in the sediment were ranked in the order of Cd>As>Pb>Cu>Zn>Cr. Overall, the extent of potential ecological risks of the mining area were categorised as having low to moderate ecological risk.

High performance sinter-HIP for hard metals

International Nuclear Information System (INIS)

Hongxia Chen; Deming Zhang; Yang Li; Jingping Chen

2001-01-01

The horizontal sinter-HIP equipment with great charge capacity and high performance, developed and manufactured by Central Iron and Steel Research Institute(CISRI), is mainly used for sintering and condensation of hard metals. This equipment is characterized by large hot zone, high heating speed, good temperature uniformity and fast cooling system. The equipment can provide uniform hot zone with temperature difference less than 6 o C at 1500-1600 o C and 6-10 MPa by controlling temperature, pressure and circulation of gas precisely. Using large scale horizontal sinter-HIP equipment to produce hard matals have many advantages such as stable quality, high efficiency of production, high rate of finished products and low production cost, so this equipment is a good choice for manufacturer of hard metals. (author)

Cave Entrance dependent Spore Dispersion of Filamentous Fungi Isolated from Various Sediments of Iron Ore Cave in Brazil: a colloquy on human threats while caving

Directory of Open Access Journals (Sweden)

Erika Linzi Silva Taylor

2014-04-01

Full Text Available Caves are stable environments with characteristics favoring the development of fungi. The fungal community present in a cave also includes pathogenic and opportunistic species out of which some are also served as energy sources in such energy stared ecosystems. Studies on microbial diversity and their role on such energy starved ecosystem are scarce. The present study was aimed to identify the cultivable filamentous fungi present in the various sediment of an iron ore cave and to recognize them as pathogenic and/or opportunistic species. Further the impact of cave entrance on the spore depositions on various distances dependent sediments were analyzed. The results suggest a diverse microbial community inhabiting the cave and an influence of cave entrance over spore deposition on various sediments. We counted a total of 4,549 filamentous fungi that included 34 species of 12 genera: Acremonium, Aspergillus, Cladosporium, Fusarium, Geotrichum, Paecilomyces, Purpureocillium, Penicillium, Torula, Trichoderma, Mucor and Rhizopus. A positive significant relation was observed between spore deposition and distance from cave entrance (p= 0.001. Areas of potential mycoses risks were recognized. This is the first study on microbiological community of an iron ore cave in the country.

Influence of sintering temperature on the properties of pulsed electric current sintered hybrid coreshell powders

Czech Academy of Sciences Publication Activity Database

Mahmed, N.; Larismaa, J.; Heczko, Oleg; Cura, M.E.; Hannula, S.-P.

2013-01-01

Roč. 33, č. 12 (2013), s. 2233-2239 ISSN 0955-2219 R&D Projects: GA ČR(CZ) GAP107/11/0391 Institutional support: RVO:68378271 Keywords : sintering * silver * iron oxide * SiO 2 * phase transformation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.307, year: 2013 http://dx.doi.org/10.1016/j.jeurceramsoc.2012.12.023

Effect of processing conditions on microstructural features in Mn–Si sintered steels

Energy Technology Data Exchange (ETDEWEB)

Oro, Raquel, E-mail: raqueld@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE-41296 Gothenburg (Sweden); Hryha, Eduard, E-mail: hryha@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE-41296 Gothenburg (Sweden); Campos, Mónica, E-mail: campos@ing.uc3m.es [Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Av. Universidad 30, 28911 Leganés, Madrid (Spain); Torralba, José M., E-mail: torralba@ing.uc3m.es [Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Av. Universidad 30, 28911 Leganés, Madrid (Spain); IMDEA Materials Institute, c/Eric Kandel, 2, 28906 Getafe, Madrid (Spain)

2014-09-15

Sintering of steels containing oxidation sensitive elements is possible if such elements are alloyed with others which present lower affinity for oxygen. In this work, a master alloy powder containing Fe–Mn–Si–C, specifically designed to create a liquid phase during sintering, has been used for such purpose. The effect of processing conditions such as sintering temperature and atmosphere was studied with the aim of describing the microstructural evolution as well as the morphology and distribution of oxides in the sintered material, evaluating the potential detrimental effect of such oxides on mechanical properties. Chemical analyses, metallography and fractography studies combined with X-ray photoelectron spectroscopy analyses on the fracture surfaces were used to reveal the main mechanism of fracture and their correlation with the chemical composition of the different fracture surfaces. The results indicate that the main mechanism of failure in these steels is brittle fracture in the surrounding of the original master alloy particles due to degradation of grain boundaries by the presence of oxide inclusions. Mn–Si oxide inclusions were observed on intergranular decohesive facets. The use of reducing atmospheres and high sintering temperatures reduces the amount and size of such oxide inclusions. Besides, high heating and cooling rates reduce significantly the final oxygen content in the sintered material. A model for microstructure development and oxide evolution during different stages of sintering is proposed, considering the fact that when the master alloy melts, the liquid formed can dissolve some of the oxides as well as the surface of the surrounding iron base particles. - Highlights: • Oxide distribution in steels containing oxidation-sensitive elements • Mn, Si introduced in a master alloy powder, mixed with a base iron powder • Selective oxidation of Mn and Si on iron grain boundaries • Decohesive fracture caused by degradation of grain

Effect of processing conditions on microstructural features in Mn–Si sintered steels

International Nuclear Information System (INIS)

Oro, Raquel; Hryha, Eduard; Campos, Mónica; Torralba, José M.

2014-01-01

Sintering of steels containing oxidation sensitive elements is possible if such elements are alloyed with others which present lower affinity for oxygen. In this work, a master alloy powder containing Fe–Mn–Si–C, specifically designed to create a liquid phase during sintering, has been used for such purpose. The effect of processing conditions such as sintering temperature and atmosphere was studied with the aim of describing the microstructural evolution as well as the morphology and distribution of oxides in the sintered material, evaluating the potential detrimental effect of such oxides on mechanical properties. Chemical analyses, metallography and fractography studies combined with X-ray photoelectron spectroscopy analyses on the fracture surfaces were used to reveal the main mechanism of fracture and their correlation with the chemical composition of the different fracture surfaces. The results indicate that the main mechanism of failure in these steels is brittle fracture in the surrounding of the original master alloy particles due to degradation of grain boundaries by the presence of oxide inclusions. Mn–Si oxide inclusions were observed on intergranular decohesive facets. The use of reducing atmospheres and high sintering temperatures reduces the amount and size of such oxide inclusions. Besides, high heating and cooling rates reduce significantly the final oxygen content in the sintered material. A model for microstructure development and oxide evolution during different stages of sintering is proposed, considering the fact that when the master alloy melts, the liquid formed can dissolve some of the oxides as well as the surface of the surrounding iron base particles. - Highlights: • Oxide distribution in steels containing oxidation-sensitive elements • Mn, Si introduced in a master alloy powder, mixed with a base iron powder • Selective oxidation of Mn and Si on iron grain boundaries • Decohesive fracture caused by degradation of grain

Interaction of kaolin containing ores with natrium and calcium chlorides

International Nuclear Information System (INIS)

Sokhibov, I.Sh.; Dadabaeva, G.; Mirzoev, B.; Safiev, H.; Boboev, Kh.E.

1997-01-01

The impact of different factors on ore agglomeration at presence of carbon activators CaCl 2 and NaCl 2 was studied. The impact of different factors on water and hydrochloric acid processing of obtained cake was studied as well. The temperature influence was studied at temperature range 600-1000 deg C during 90 min sintering. The obtained cakes were leached by water in acid medium and were used as coagulants for water purification from suspended matters.

The Influences of Iron Ore Tailings as Fine Aggregate on the Strength of Ultra-High Performance Concrete

Directory of Open Access Journals (Sweden)

Zhigang Zhu

2015-01-01

Full Text Available The present study looks for the feasibility of preparing UHPC with iron ore tailings (IOT for short as fine aggregate. To enhance outstanding high performances, some influences on UHPC mortars were investigated such as different kinds of sands, different mix ratio of sands, and different largest particle size of fine aggregate. The results show that IOT have negligible poorer aggregate performance than silica sands but better than river sands. The strength of UHPC reaches the highest point when silica sands were instead 60% by IOT. As the largest particle size of fine aggregate is decreasing, the strength and frost resistance of UHPC were improved, but the liquidity was decreased. Micropowder of IOT affects the strength and the optimal content was 4%.

Changes of Fe matrix lattice constant during liquid phase sintering of Fe-Cu-C compacts by x-ray diffraction techniques

International Nuclear Information System (INIS)

Mazli Mustapha; Abdul Kadir Masrom; Mohammad, M.; Meh, B.; Zawati Harun

2002-01-01

The dissolution of graphite and copper during sintering of PM steels prepared from iron, copper and graphite powder mixes were studied using X-Ray Diffraction method. This paper present the investigation carried out to study the changes of iron's lattice constant during liquid phase sintering of the compacts. The electrical conductivity measurement method was also used for determining the extent of carbon and copper dissolution and its influence on the formation of sintered compacts. In the experiment, the Fe-Cu-C powders were compacted into a pellets using hand press machine and were then sintered in a 5% H 2 + 95% N 2 gas atmosphere at different sintering temperature in the range of 400 degree C and 1200 degree C. The effect of sintering parameters on the mechanical properties of the sintered compacts was studied to find a correlation between mechanical behaviour, microstructure, and the resistivity in order to develop nondestructive testing method. It was observed that measurement of Fe matrix lattice constant and electrical conductivity of sintered compacts could be a viable method in studying all stages of sintering process. (Author)

Neutron shielding properties of boron-containing ore and epoxy composites

International Nuclear Information System (INIS)

Li Zhifu; Xue Xiangxin

2011-01-01

Using the boron-containing iron ore concentrate and boron-rich slag as studying object, the starting materials were got after the specific green ore containing boron dressing in China and blast furnace separation respectively. Monte-Carlo method was used to study the effect of the boron-containing iron ore concentrate and boron-rich slag and their composites with epoxy on the neutron shielding abilities. The reasons that affecting the shielding materials properties was discussed and the suitable proportioning of boron-containing ore to epoxy composites was confirmed; the 14.1 MeV fast neutron removal cross section and the total thermal neutron attenuation coefficient were obtained and compared with that of the common used concrete. The results show that the shielding property of 14.1 MeV fast neutron is mainly concerned with the low-Z elements in the shielding materials, the thermal neutron shielding ability is mainly concerned with boron concentrate in the composite, the attenuation of the accompany γ-ray photon is mainly concerned with the high atom number elements content in the ore and the density of the shielding material. The optimum Janume fractions of composites are in the range of 0.4-0.6 and the fast neutron shielding properties are similar to concrete while the thermal neutron shielding properties are higher than concrete. The composites are expected to be used as biological concrete shields crack injection and filling of the anomalous holes through the concrete shields around the radiation fields or directly to be prepared as shielding materials.(authors)

Mutualism between autotrophic and heterophic bacteria in leaching of low grade ores

International Nuclear Information System (INIS)

Khalid, Z.M.; Naeveke, R.

1991-01-01

During solubilization processes of low grade sulphidic ores, the auto trophic bacteria oxidize reduced sulphur compounds and ferrous iron to sulphates and ferric iron respectively. The ore leaching bio topes are not only colonized by auto trophic bacteria (Thiobacillus spp., Leptospirillum ferro oxidans and sulfolobus sp.) but the heterotrophic microorganisms, including bacteria and fungi of various species are also found in these habitats. The autotrophs, in addition to energy metabolism, also produce organic compounds which in excess amount inhibit their growth. Through the utilization of such compounds and also through the production of carbon dioxide and ammonia, these heterotorphs can help bio leaching processes. Effect of one of the heterotrophs; methylobacterium sp., a nitrogen scavenger, found in as association with the thio bacilli in one of the leaching bio tope in Germany was studied in leaching of a carbonate bearing complex (containing copper, iron, zinc and lead) sulphidic ore, in shake flask studies. T. ferro oxidans (Strain F-40) reported to be non nitrogen fixer and strain F-41, a nitrogen fixing thiobacillus were studied for leachability behaviour alone and in combination with T. thio oxidans (lacking nitrogen fixing ability) using media with and without added ammonium nitrogen. In addition the effect of methylobacterium sp. (alt-25) was also tested with the afore mentioned combinations. Nitrogen fixation by T. ferro oxidans did not suffice the nitrogen requirement and the leaching system in laboratory needed addition of nitrogen. The heterotrophic nitrogen scavenger also did not have a positive influence in nitrogen limited system. In case where ammonium nitrogen was also provided in the media, this heterotroph had a negative in own growth and leaving lesser amount available for thio bacilli. This high amount of acid is a limiting factor in bio leaching of high carbonate uranium ores. Uranium ore ecosystems have also been found to contain

Decline in the lung cancer hazard: a prospective study of the mortality of iron ore miners in Cumbria

International Nuclear Information System (INIS)

Kinlen, L.J.

1988-01-01

The mortality of 1947 Cumbrian iron ore miners has been studied over the period 1939-82 in relation to that among other groups of men in England and Wales: (a) all men, (b) men of similar social class, and (c) men living in similar types of (mainly rural) area. Significant excesses were found for deaths from tuberculosis and respiratory diseases compared with each of the reference populations. Lung cancer showed an excess over that in comparable (mainly rural) areas of England and Wales, as reported in a previous study using a proportionate method of analysis and which covered the period 1948-67 but no appreciable excess after 1967. Reasons for this decline are discussed. (author)

Natural radioactivity in iron and steel materials by low-level gamma spectrometry

International Nuclear Information System (INIS)

Tanase, G.; Tanase, Maria

2003-01-01

High resolution low-level gamma spectrometry was applied to perform a radioactivity measurement in iron and steel raw materials (coal, coke, iron ore, pellets, manganese ore, limestone, dolomite), auxiliary materials (scorialite, oxide of Ti, bentonite), and some related final products (cast iron, slag, blast-furnace, flue dust) involved in iron making processing. We control the activity of materials in various kinds of samples and we investigate for transfer of radioactivity during the blast-furnace process. Artificial radioisotopes are rarely encountered. (authors)

Surface phenomena during the early stages of sintering in steels modified with Fe–Mn–Si–C master alloys

Energy Technology Data Exchange (ETDEWEB)

Oro, Raquel, E-mail: raqueld@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE-41296 Gothenburg (Sweden); Campos, Mónica, E-mail: campos@ing.uc3m.es [Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Av. Universidad 30, 28911 Leganés, Madrid (Spain); Hryha, Eduard, E-mail: hryha@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE-41296 Gothenburg (Sweden); Torralba, José Manuel, E-mail: torralba@ing.uc3m.es [Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Av. Universidad 30, 28911 Leganés, Madrid (Spain); IMDEA Materials Institute, C/Eric Kandel, 2, 28906 Getafe, Madrid (Spain); Nyborg, Lars, E-mail: lars.nyborg@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE-41296 Gothenburg (Sweden)

2013-12-15

The characteristics of the metallic powder surface play a critical role in the development of strong bonds between particles during sintering, especially when introducing elements with a high affinity for oxygen. In this study, Mn and Si have been combined in a Fe–Mn–Si–C master alloy powder in order to reduce their chemical activity and prevent oxidation during the heating stage of the sintering process. However, when this master alloy powder is mixed with an iron base powder, differences in chemical activity between both components can lead to an oxygen transfer from the iron base powder to the surface of the master alloy particles. The present research is focused on studying the evolution of the master alloy particle surface during the early stages of sintering. Surface characterization by X-ray Photoelectron Spectroscopy (XPS) shows that the master alloy powder surface is mostly covered by a thin easily reducible iron oxide layer (∼ 1 nm). Mn–Si particulate oxides are found as inclusions in specific areas of the surface. Evolution of oxides during sintering was studied on green compacts containing iron powder, graphite and Fe–Mn–Si–C master alloy powder that were heat treated in vacuum (10{sup −6} mbar) at different temperatures (from 400, 600, 800 to 1000 °C) and analyzed by means of XPS. Vacuum sintering provides the necessary conditions to remove manganese and silicon oxides from the powder surface in the range of temperatures between 600 °C and 1000 °C. When sintering in vacuum, since the gaseous products from reduction processes are continuously eliminated, oxidation of master alloy particles due to oxygen transfer through the atmosphere is minimized. - Highlights: • Mn and Si were introduced in sintered steels using a master alloy powder. • Surface of the master alloy is mainly covered by an easily reducible iron oxide. • Temperature ranges for oxidation/reduction are identified. • Vacuum conditions avoid oxygen transfer to

Effects of atmospheric gas composition and temperature on the gasification of coal in hot briquetting carbon composite iron ore

Energy Technology Data Exchange (ETDEWEB)

Ueki, Y.; Kanayama, M.; Maeda, T.; Nishika, K.; Shimizu, M. [Kyushu University, Fukuoka (Japan). Dept. of Materials Science & Engineering

2007-01-15

The gasification behavior of carbon composite iron ore produced by hot briquetting process was examined under various gas atmospheres such as CO-N{sub 2}, CO{sub 2}-N, and CO-CO{sub 2} at various temperatures. The gasification of coal was affected strongly by atmospheric gas concentration and reaction temperature. Kinetic analysis in various gas atmospheres was carried out by using the first order reaction model, which yields the straight line relation between reaction rate constants for the gasification of coal and the gas concentration. Therefore, reaction rate constants for the gasification of coal in CO-CO{sub 2}-N{sub 2} gas atmosphere were derived.

Water requirements of the iron and steel industry

Science.gov (United States)

Walling, Faulkner B.; Otts, Louis Ethelbert

1967-01-01

Twenty-nine steel plants surveyed during 1957 and 1958 withdrew from various sources about 1,400 billion gallons of water annually and produced 40.8 million tons of ingot steel. This is equivalent to about 34,000 gallons of water per ton of steel. Fifteen iron ore mines and fifteen ore concentration plants together withdrew annually about 89,000 million gallons to produce 15 million tons of iron ore concentrate, or 5,900 gallons per ton of concentrate. About 97 percent of the water used in the steel plants came from surface sources, 2.2 percent was reclaimed sewage, and 1.2 percent was ground water. Steel plants supplied about 96 percent of their own water requirements, although only three plants used self-supplied water exclusively. Water used by the iron ore mines and concentration plants was also predominantly self supplied from surface source. Water use in the iron and steel industry varied widely and depended on the availability of water, age and condition of plants and equipment, kinds of processes, and plant operating procedures. Gross water use in integrated steel plants ranged from 11,200 to 110,000 gallons per ton of steel ingots, and in steel processing plants it ranged from 4,180 to 26,700 gallons per ton. Water reuse also varied widely from 0 to 18 times in integrated steel plants and from 0 to 44 times in steel processing plants. Availability of water seemed to be the principal factor in determining the rate of reuse. Of the units within steel plants, a typical (median) blast furnace required 20,500 gallons of water per ton of pig iron. At the 1956-60 average rate of pig iron consumption, this amounts to about 13,000 gallons per ton of steel ingots or about 40 percent of that required by a typical integrated steel plant 33,200 gallons per ton. Different processes of iron ore concentration are devised specifically for the various kinds of ore. These processes result in a wide range of water use from 124 to 11,300 gallons of water per ton of iron ore

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

1998-01-01

Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

Utilization potentiality of coal as a reductant for the production of sponge iron. [5 refs

Energy Technology Data Exchange (ETDEWEB)

Mishra, H P

1976-10-01

With the ambitious plan of the Government of India to produce about 70 million tonnes of steel per annum towards the end of the century, the requirement of coal would be enormous. This calls for judicious planning and conservation of coal. Modern trend in steel plant practice is to use blast furnaces of capacity 10,000 to 12,000 t/day requiring superior quality coke of low ash content which will become scarce. Concerted efforts should be made to by-pass blast furnace technique by adopting direct reduction for the production of metallized iron ore, that is sponge iron, and using this as feed stock in electric furnaces. Experience has shown that the use of sponge iron as feed stock for electric arc furnaces instead of the scrap available from various fabrication and steel works results in better production of alloy steels. The use of non-coking coal as reductant for production of sponge iron will help conserve coking coal for bigger steel plants. In the solid state reduction process the technological design of the sponge iron plant has to be tailored to the type of feed stock to be used, particularly iron ore and coal. In India, non-coking coal is available at close proximity to the iron ore mines containing high grade iron ore. Planning for sponge iron, utilizing large reserves of non-coking coal as feed stock therefore has considerable potentiality. India has vast reserves of high grade iron ore and comparatively meager amount of coking coal. This calls for planning for sponge iron using non-coking coal as feed stock.

Tantalum and niobium carbides obtention by carbothermic reduction of columbotantalite ores

International Nuclear Information System (INIS)

Gordo, E.; Garcia-Carcedo, F.; Torralba, J.M.

1998-01-01

Tantalum and niobium carbides are characterized by its high hardness and chemical corrosion resistance. Both carbides, but mainly TaC, are used in hard metals (sintered carbides), together with their carbides, to manufacture cutting tools and dies in special machining applications involving mechanical shock at high temperature. Its use as reinforcement of wear resistant materials through powder metallurgy techniques are being investigated. However, the use of TaC is usually limited because of its high cost. Therefore tantalum carbide with niobium content, which is cheaper, is used. In this work the obtention of complex tantalum and niobium carbides from a Spanish columbotantalite ore is studied through relatively cheap and simple process as it is carbothermic reduction. Concentration of the ore, its reduction and the characterization of products are described. (Author) 11 refs

Ores and Climate Change - Primary Shareholders

Science.gov (United States)

Stein, Holly J.; Hannah, Judith L.

2015-04-01

Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

On-line sampling of apatite-nepheline ore using apron feeders by gamma-gamma method

Energy Technology Data Exchange (ETDEWEB)

Bliznyuk, G.I.

1981-01-01

The yield flow of an underground mine equipped with a crushing complex was investigated. /sup 241/Am source and 20x20 mm NaI(Tl) crystal were used; the lump size of apatite-nepheline ore was 200 mm, P/sub 2/O/sub 5/ content varied from 10 to 22%. The mean-square error was 1% P/sub 2/O/sub 5/ in 100-ton portions of mined ore. The method can be also applied for sampling iron, copper-nickel, and polymetallic ores.

Iron ore sintering. Part 3: Automatic and control systems

Directory of Open Access Journals (Sweden)

Alejandro Cores

2015-01-01

Full Text Available El proceso de sinterización implica un gran número de parámetros, más de quinientos, cada uno de los cuales ejerce una mayor o menor influencia y necesita ser controlado, dentro de los límites posibles, con el fin de optimizar la productividad, la estabilidad del proceso, y la composición y la calidad de la sinterizado producido. Para cumplir con la legislación ambiental, un sistema de control de la contaminación debe monitorizar la composición de las partículas y los gases generados en la planta de sinterización y emitidos a la atmósfera. Los sistemas de automatización y control son herramientas vitales para ayudar a los operadores de la planta en el seguimiento de cada etapa del proceso de producción de sinterizado.

Effect of processing variables on mechanical properties of sintered manganese steels Fe-3%Mn-0.8%C

International Nuclear Information System (INIS)

Sulowski, M.; Cias, A.

1998-01-01

The powder metallurgy route may allow sintered manganese steels to be made based on pure iron powder and ferromanganese powder with control over alloy microstructure. The factors that contribute to the mechanical properties of sintered Fe-3%Mn-0.8%C manganese steel, such as the sintering atmosphere, dew point, sintering temperature, cooling rate are summarised. The paper shows the influence of these parameters on the tensile strength, yield strength, transverse rupture strength, impact strength and hardness. It is showed that tensile high strength level higher than those of many present sintered steels can be obtained already in the as-sintered condition. (author)

Hepatic retinoid levels in seven fish species (teleosts) from a tropical coastal lagoon receiving effluents from iron-ore mining and processing.

Science.gov (United States)

Pereira, Adriana A; van Hattum, Bert; Brouwer, Abraham

2012-02-01

The present study was undertaken to investigate the possible effects of Fe and trace element exposure on hepatic levels of retinoids in seven fish species. Concentrations of retinoids were measured in fish collected from a coastal lagoon in Brazil that receives effluents from an iron-ore mining and processing plant. Fish from nearby coastal lagoons were also included to assess possible differences related to chemical exposure. Results indicated considerable differences in hepatic retinoid composition among the various species investigated. The most striking differences were in retinol and derivative-specific profiles and in didehydro retinol and derivative-specific profiles. The Perciformes species Geophagus brasiliensis, Tilapia rendalli, Mugil liza, and Cichla ocellaris and the Characiforme Hoplias malabaricus were characterized as retinol and derivative-specific, while the Siluriformes species Hoplosternum littorale and Rhamdia quelen were didehydro retinol and derivative-specific fish species. A negative association was observed between Al, Pb, As, and Cd and hepatic didehydro retinoid levels. Fish with higher levels of hepatic Fe, Cu, and Zn showed unexpectedly significant positive correlations with increased hepatic retinol levels. This finding, associated with the positive relationships between retinol and retinyl palmitate with lipid peroxidation, may suggest that vitamin A is mobilized from other tissues to increase hepatic antioxidant levels for protection against oxidative damage. These data show significant but dissimilar associations between trace element exposure and hepatic retinoid levels in fish species exposed to iron-ore mining and processing effluents, without apparent major impacts on fish health and condition. Copyright © 2011 SETAC.

Determination of rare earth elements in products of Chadormalu iron ore concentrator plant (Iran) from beneficiation point of view

International Nuclear Information System (INIS)

Jorjani, E.; Bagherieh, A. H.; Rezai, B.

2007-01-01

:Different samples have been prepared from different products in Chadormalu iron ore concentrator plant: Low intensity magnetite separators concentrate (magnetite concentrate), reverse flotation tail (final hematite concentrate), flotation concentrate (apatite concentrate), final tail (L.I. M.S. tail + reverse flotation concentrate + apatite flotation tail). The samples were used for rare earth elements (REEs) distribution and origin studies. The assay of REEs was determined by ICP-MS spectrometry. The amount of total (light and heavy) REEs were 9631, 291, 199, 2236 ppm and the distributions were 19.3, 3.6, 10.1, 67% in flotation concentrate (apatite concentrate), reverse flotation tail (hematite concentrate), magnetite concentrate and total tail respectively. About 19.3% of total REEs were distributed in apatite concentrate with an assay of 9631 ppm. Therefore, further studies have been conducted on this product. According to the Xray studies the minerals of fluoroapatite, ankerite and calcite are the main mineral phases in apatite concentrate which the apatite is dominant among them. The scanning electron microscopy studies were shown that the high amount of REEs distributed on fluoroapatite mineral. The results have clearly shown that the apatite concentrate that is a by product of iron dressing in Chadormalu plant, with a low economical value and left without any further treatment, can be used as a significant source of REEs. According to this characterization studies, the recovery of a mixed rare earth oxide from fluoroapatite is possible either with the treatment of liquors from the total dissolution of the ore in nitric acid or with the proposed treatment of the phosphogypsum by-product from the conventional sulphuric acid route and the recovery of rare earth oxides from phosphoric acid sludges that the detailed flowsheet needs further extraction work

Quantitative Investigation of Roasting-magnetic Separation for Hematite Oolitic-ores: Mechanisms and Industrial Application

Directory of Open Access Journals (Sweden)

Peng Tiefeng

2017-12-01

Full Text Available Natural high-quality iron can be directly applied to pyro-metallurgy process, however, the availability of these ores has become less and less due to exploitation. This research reports a systematic approach using reduction roasting and magnetic separation for oolitic iron ores from west Hubei Province. Firstly, a mineralogical study was performed and it was shown that the oolitic particles were mainly composed of hematite, with some silicon-quartz inside the oolitic particle. Then, the roasting temperature was examined and shown to have significant influence on both Fe recovery and the Fe content of the concentrate. Also the Fe content gradually increased as the temperature increased from 700 to 850 °C. The most important aspects are the quantitative investigation of change of mineral phases, and reduction area (with ratio during the reduction roasting process. The results showed that Fe2O3 decreased with temperature, and Fe3O4 (magnetite increased considerably from 600 to 800 °C. The reductive reaction was found to occur from the outside in, the original oolitic structure and embedding relationship among the minerals did not change after roasting. Finally, 5% surrounding rock was added to mimic real industrial iron beneficiation. This study could provides useful insight and practical support for the utilization of such iron ores.

Multiple Stage Ore Formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: Evidence from BSE Imaging and Apatite EPMA and LA-ICP-MS U-Pb Geochronology

Directory of Open Access Journals (Sweden)

Hassan Heidarian

2018-02-01

Full Text Available The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold (IOCG and iron oxide-apatite (IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks. Textural evidence (SEM-BSE images of these apatites shows primary bright, and secondary dark areas with inclusions of monazite/xenotime. The primary, monazite-free fluorapatite contains higher concentrations of Na, Si, S, and light rare earth elements (LREE. The apatite was altered by hydrothermal events that led to leaching of Na, Si, and REE + Y, and development of the dark apatite. The bright apatite yielded two U-Pb age populations, an older dominant age of 490 ± 21 Ma, similar to other iron deposits in the Bafq district and associated intrusions, and a younger age of 246 ± 17 Ma. The dark apatite yielded a U-Pb age of 437 ± 12 Ma. Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran.

Nine years of charcoal continuous sintering in Belgo-Mineira Iron and Steel Company (BMISC); Nove anos de operacao da sinterizacao continua a carvao vegetal da Companhia Siderurgica Belgo Mineira (CSBM)

Energy Technology Data Exchange (ETDEWEB)

Mines, Claude Rene Camille; Lamas, Vicente Paulo Barroso; Junqueira, Sergio Almeida; Castro, Riolando de Souza; Vital, Raimundo Geraldo; Vieira, Nelson [Companhia Siderurgica Belgo Mineira, Joao Monlevade, MG (Brazil)

1988-12-31

The principal data of the continuous sintering plant from Belgo Mineira Iron and Steel Company, Brazil, are shown. The evolution of data and the operational procedures to obtain them are discussed. The procedures to improve data are also described. (author) 1 ref., 6 figs., 2 tabs.

Temperature Field Simulation of Powder Sintering Process with ANSYS

Science.gov (United States)

He, Hongxiu; Wang, Jun; Li, Shuting; Chen, Zhilong; Sun, Jinfeng; You, Ying

2018-03-01

Aiming at the “spheroidization phenomenon” in the laser sintering of metal powder and other quality problems of the forming parts due to the thermal effect, the finite element model of the three-dimensional transient metal powder was established by using the atomized iron powder as the research object. The simulation of the mobile heat source was realized by means of parametric design. The distribution of the temperature field during the sintering process under different laser power and different spot sizes was simulated by ANSYS software under the condition of fully considering the influence of heat conduction, thermal convection, thermal radiation and thermophysical parameters. The influence of these factors on the actual sintering process was also analyzed, which provides an effective way for forming quality control.

Bacterial bioleaching of low grade nickel limonite and saprolite ores by mixotrophic bacteria

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Chaerun Siti Khodijah

2016-01-01

Full Text Available Utilization of indigenous bacteria should be considered to establish a successful biohydrometallurgical process. In this study, mixrotrophic iron-oxidizing bacterial consortia consisting of Comamonas testosteroni, Alicyclobacillus ferrooxydans and Pantoea septic which were isolated from Indonesian mineral ores were examined to determine their abilities to recover nickel from limonite and saprolite ores in the bioleaching experiments using stirred tank reactors. The nickel bioleaching experiments inoculated with the bacterial consortia were carried out using coarse limonite ores and weathered saprolite ores with pulp density of 10% w/v. Abiotic controls were also carried out replacing the inocula by the sterile medium. The bioleaching processes were monitored by measuring Ni and Fe contents and pH of the leaching solution as well as the total bacterial enzymatic activity measured as FDA hydrolytic activity. The effect of leaching on the mineralogy of laterite ores was investigated by the scanning electron microscope equipped with energy-dispersive spectroscopy (SEM-EDS and X-ray powder diffraction (XRD. After 28 days of incubation, the FDA hydrolytic activity was observed in both bioleaching experiments containing limonite (17.2 μg fluorescein/mL and saprolite ores (16.9 μg fluorescein/mL. The leached Ni and Fe in the bioleaching experiments containing limonite ores (30% Ni and 5.6% Fe was greater than that in abiotic controls (1% Ni and 0.1% Fe with the pH range of 2.5 to 3.5. However, the bacterial consortia were less capable of bioleaching of Ni (2.5% with the similar leached Fe (6% from the saprolite ores. In abiotic controls, the medium pH remained relatively constant (pH 6. It was concluded that these bacterial isolated as the consortium were capable of nickel bioleaching (precious metal more effectively than iron (gangue metal, thus being applicable to the commercial processing of the difficult-to-process low-grade nickel laterite ores

Features structure of iron-bearing strata’s of the Bakchar deposit, Western Siberia

Science.gov (United States)

Asochakova, E. M.

2017-12-01

The ore-bearing strata’s of Bakchar deposit have complicated structural-textural heterogeneity and variable mineral composition. This deposit is one of the most promising areas of localization of sedimentary iron ore. The ore-bearing strata’s are composed mainly of sandstones (sometimes with ferruginous pebbles, less often conglomerates), siltstones and clays. The ironstones are classified according to their lithology and geochemistry into three types: goethite-hydrogoethitic oolitic, glauconite-chloritic and transitional (intermediate) type iron ores. The mineral composition includes many different minerals: terrigenous, authigenic and clayey. Ironstones are characterized by elevated concentrations of many rare and valuable metals present in them as trace elements, additionally alloying (Mn, V, Cr, Ti, Zr, Mo, etc.) and harmful impurities (S, As, Cu, Pb, Zn, P). There are prerequisites for the influence of numerous factors, such as prolonged transgression of the sea, swamping of paleo-river deltas, the appearance of a tectonic fracture zone associated with active bottom tectonics and unloading of catagenetic waters, regression and natural ore enrichment due to the re-washing of slightly-iron rocks. These factors are reflected in the structure of the ore-bearing strata in which rhythmic cycles of ore sedimentation with successive changes in them are distinguished by an association of different mineral composition.

Predicting the Concentration Characteristics of Itakpe Iron Ore for cut ...

African Journals Online (AJOL)

MICHAEL HORSFALL

ABSTRACT: Concentration characteristics of an ore are very critical to the estimation of cut-off grade of a ... enormous financial cost of laboratory analysis and time required for such .... Arua A.I. (1997) Fundamentals of statistics, Publisher,.

Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

Science.gov (United States)

Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.

2001-03-01

Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

Laser Sintering Technology and Balling Phenomenon.

Science.gov (United States)

Oyar, Perihan

2018-02-01

The aim of this review was to evaluate the balling phenomenon which occurs typically in Selective Laser Sintering (SLS). The balling phenomenon is a typical SLS defect, and observed in laser sintered powder, significantly reduces the quality of SLS, and hinders the further development of SLS Technology. Electronic database searches were performed using Google Scholar. The keywords "laser sintering, selective laser sintering, direct metal laser melting, and balling phenomenon" were searched in title/abstract of publications, limited to December 31, 2016. The inclusion criteria were SLS, balling phenomenon, some alloys (such as Cr-Co, iron, stainless steel, and Cu-based alloys) mechanical properties, microstructure and bond strength between metal-ceramic crown, laboratory studies, full text, and in English language. A total of 100 articles were found the initial search and yielded a total of 50 studies, 30 of which did not fulfill the inclusion criteria and were therefore excluded. In addition, 20 studies were found by screening the reference list of all included publications. Finally, 40 studies were selected for this review. The method in question is regulated by powder material characteristics and the conditions of laser processing. The procedure of formation, affecting factors, and the mechanism of the balling effect are very complex.

Influence of the radial spacing between cathodes on the surface composition of iron samples sintered by hollow cathode electric discharge

Directory of Open Access Journals (Sweden)

Brunatto S.F.

2001-01-01

Full Text Available The present work reports an investigation of the influence of the radial spacing between cathodes on the iron sintering process by hollow cathode electrical discharge, with surface enrichment of the alloying elements Cr and Ni. Pressed cylindrical samples of 9.5 mm diameter and density of 7.0 ± 0.1 g/cm³ were prepared by compaction of Ancorsteel 1000C iron powder. These samples, constituting the central cathode, were positioned concentrically in the interior of an external cathode machined from a tube of stainless steel AISI 310 (containing: 25% Cr, 16% Ni, 1.5% Mn, 1.5% Si, 0.03% C and the remainder Fe. Sintering was done at 1150 °C, for 120 min, utilizing radial spacings between the central and hollow cathodes of 3, 6 and 9 mm and a gas mixture of 80% Ar and 20% H2, with a flow rate of 5 cm³/s at a pressure of 3 Torr. The electric discharge was generated using a pulsed voltage power source, with a period of 200 mus. The radial spacing had only a slight influence on the quantity of atoms of alloying elements deposited and diffused on the surface of the sample. Analysis with a microprobe showed the presence of chrome (up to 4.0% and nickel (up to 3.0%, in at. % at the surface of the samples. This surface enrichment can be attributed to the mechanism of sputtering of the metallic atoms present in the external cathode, with the deposition of these elements on the sample surface and consequent diffusion within the sample.

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.)

Compacted graphite iron: Cast iron makes a comeback

Science.gov (United States)

Dawson, S.

1994-08-01

Although compacted graphite iron has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite iron together with its low cost and recyclability reinforce cast iron as a prime engineering material for the future.

Thallium-rich pyrite ores from the Apuan Alps, Tuscany, Italy:constraints for their origin and environmental concerns

Science.gov (United States)

D'Orazio, Massimo; Biagioni, Cristian; Dini, Andrea; Vezzoni, Simone

2017-06-01

The southern sector of the Apuan Alps (AA) massif, Tuscany, Italy, is characterized by the occurrence of a series of baryte-pyrite-iron oxide orebodies whose Tl-rich nature was recognized only recently. The geochemistry of the pyrite ore was investigated through inductively coupled plasma mass spectrometry. In addition, lead isotope data for selected pyrite ores from AA were collected. Pyrite ores are characterized by a complex geochemistry, with high concentrations of Tl (up to 1100 μg/g) coupled with high As and Sb contents; the Co/Ni ratio is always <1. Geochemical data of pyrite and marcasite ore samples from other mining districts of Tuscany have been collected in order to compare them with those from the AA. These samples usually have very low Tl content (less than 2 μg/g) and high to very high Co/Ni and As/Sb ratios. Only some samples from the Sb-Hg ore deposits showed very high Tl concentrations (up to 3900 μg/g). Another difference is related to the lead isotope composition, with pyrite ores from AA markedly less radiogenic than those from the other deposits from Tuscany. Geochemical data of pyrite ores from AA give new insights on the genesis of the baryte-pyrite-iron oxide orebodies, relating their formation to low-temperature hydrothermal systems active during early Paleozoic; in addition, these data play a fundamental role in assessing the environmental impact of these deposits.

Influence of Sintering Temperature on Mechanical and Physical properties of Mill Scale based Bipolar Plates for PEMFC

Science.gov (United States)

Khaerudini, Deni S.; Berliana, Rina; Prakoso, Gatra B.; Insiyanda, Dita R.; Alva, Sagir

2018-03-01

This work concerns the utilization of mill scale, a by-product of iron and steel formed during the hot rolling of steel, as a potential material for use as bipolar plates in proton exchange membrane fuel cells (PEMFCs). On the other hand, mill scale is considered a very rich in iron source having characteristic required such as for current collector in bipolar plate and would significantly contribute to lower the overall cost of PEMFC based fuel cell systems. In this study, the iron reach source of mill scale powder, after sieving of 150 mesh, was mechanically alloyed with the aluminium source containing 30 wt.% using a shaker mill for 3 h. The mixed powders were then pressed at 300 MPa and sintered at various temperatures of 400, 450 and 500 °C for 1 h under inert gas atmosphere. The structural changes of powder particles during mechanical alloying and after sintering were studied by x-ray diffractometry, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), microhardness measurement, and density - porosity analysis. The details of the performance variation of three different sintering conditions can be preliminary explained by the metallographic and crystallographic structure and phase analysis as well as sufficient mechanical strength of the sintered materials was presented in this report.

Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

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Li Luo

2016-01-01

Full Text Available The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

Effect of hydrogen on reduction of burden materials

Energy Technology Data Exchange (ETDEWEB)

Hooey, P.L. [Rautaruukki Oy, Raahe (Finland). Raahe Steel

1996-12-31

Efficient operation of iron blast furnaces requires that the iron bearing burden material have good reduction, softening and melting characteristics. These characteristics are determined by the physical operation of the blast furnace and the mineralogical composition of the agglomerate. Increasing oil injection rates will increase the hydrogen content of the reducing gas significantly. The aim of this work is to establish how different burden materials react to this change in gas environment, and develop sinters which have optimal properties. The testing of sinter and pellets is broken into two areas: development of the test methods; and determination of sinter and pellet characteristics. The test method requires development because recent testwork has shown that the reducibility of the sinter is now so high that the reduction under load test is no longer sensitive. A new control program and more realistic gas compositions are currently being tested. The softening and melting characteristics of sinters of varying composition, acid pellets and olivine pellets have been tested using the reduction under load test at Rautaruukki Oy Research Centre. The effect of hydrogen in the reducing gas on the different iron ore agglomerates has been evaluated SULA 2 Research Programme; 6 refs.

Effect of hydrogen on reduction of burden materials

Energy Technology Data Exchange (ETDEWEB)

Hooey, P L [Rautaruukki Oy, Raahe (Finland). Raahe Steel

1997-12-31

Efficient operation of iron blast furnaces requires that the iron bearing burden material have good reduction, softening and melting characteristics. These characteristics are determined by the physical operation of the blast furnace and the mineralogical composition of the agglomerate. Increasing oil injection rates will increase the hydrogen content of the reducing gas significantly. The aim of this work is to establish how different burden materials react to this change in gas environment, and develop sinters which have optimal properties. The testing of sinter and pellets is broken into two areas: development of the test methods; and determination of sinter and pellet characteristics. The test method requires development because recent testwork has shown that the reducibility of the sinter is now so high that the reduction under load test is no longer sensitive. A new control program and more realistic gas compositions are currently being tested. The softening and melting characteristics of sinters of varying composition, acid pellets and olivine pellets have been tested using the reduction under load test at Rautaruukki Oy Research Centre. The effect of hydrogen in the reducing gas on the different iron ore agglomerates has been evaluated SULA 2 Research Programme; 6 refs.

RELATIONSHIP BETWEEN METAMORPHISM DEGREE AND LIBERATION SIZE OF COMPACT ITABIRITES FROM THE IRON QUADRANGLE

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Rodrigo Fina Ferreira

2015-06-01

Full Text Available Iron ore exploited in Brazil can be classified into several lithological types which have distinct features. The progress of mining over time leads to scarcity of high grade iron ores, leading to the exploitation of poor, contaminated and compact ores. There is a growing trend of application of process flowsheets involving grinding to promote mineral liberation, essential condition for concentration processes. Several authors have correlated metamorphism processes of banded iron formations to mineralogical features observed on itabirites from the Iron Quadrangle, mainly the crystals size. This paper presents the implications of such variation in defining the mesh of grinding. Mineralogical characterization and grinding, desliming and flotation tests have been carried out with samples from two regions of the Iron Quadrangle subjected to different degrees of metamorphism. It was found a trend of reaching satisfactory liberation degree in coarser size for the itabirite of higher metamorphic degree, which has larger crystals. The flotation tests have confirmed the mineralogical findings.

Evaluation of chromite ore and the optimum methods for industrial extraction of chromium

International Nuclear Information System (INIS)

Salih, Bakheit Mustafa Mohamed

1999-10-01

Samples of chromite ore, collected from Gam and Cheikay mining area (Ingaessana Hills) in east Sudan, were analysed to assess the chromium content. Analysis were carried out using atomic absorption spectroscopy (AAS) to estimate the contents of chromium, iron, calcium and magnesium. X-ray florescence (XRF) was used to evaluate the levels of chromium, iron and calcium in the ore. Volumetric analysis was performed to assess chromium and iron, whilest gravimetric analysis was employed to measure the amounts of calcium, magnesium, aluminum and silicon present in the ore. The results are in a good agreement except iron oxide, which displayed a significantly different value when measured by x-ray fluorescence. The data obtained exhibited similarity in almost all cases, when compared with local and global researches, reports and literature. The study has revealed the average contents of Cr 2 O 3 , FeO, CaO, MgO, Al 2 O 3 , and SiO 2 as 40.66, 11.96, 11.94, 0.36, 16.94, 11.45% respectively. MnO and NiO were detected in trace amounts, the corresponding levels in the ore being 72 and 27 ppm. The average chromium content in extracted potassium dichromate measured by using AAS, XRF, and volumetric methods was found to be 31.7%. The highest grade reached by individual technique being 33.10%. The extraction with sodium peroxide is the optimum method for preparation of potassium dichromate. X-ray diffraction analysis, has showed that the d spaces and intensities of prepared potassium dichromate are isostructural with the corresponding ones of standard potassium dichromate. This suggests that the composition of the two samples is identical. Chromite samples were analysed using gamma ray spectroscopy in order to estimate the levels of radioactive elements present. It was found that the concentrations of 232 Th and 40 K range from 7.62 to 10.98 Bq/kg and 47.38 to 56.28 Bq/kg respectively

Wastewater engineering applications of BioIronTech process based on the biogeochemical cycle of iron bioreduction and (biooxidation

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Volodymyr Ivanov

2014-12-01

Full Text Available Bioreduction of Fe(III and biooxidation of Fe(II can be used in wastewater engineering as an innovative biotechnology BioIronTech, which is protected for commercial applications by US patent 7393452 and Singapore patent 106658 “Compositions and methods for the treatment of wastewater and other waste”. The BioIronTech process comprises the following steps: 1 anoxic bacterial reduction of Fe(III, for example in iron ore powder; 2 surface renovation of iron ore particles due to the formation of dissolved Fe2+ ions; 3 precipitation of insoluble ferrous salts of inorganic anions (phosphate or organic anions (phenols and organic acids; 4 (biooxidation of ferrous compunds with the formation of negatively, positively, or neutrally charged ferric hydroxides, which are good adsorbents of many pollutants; 5 disposal or thermal regeration of ferric (hydroxide. Different organic substances can be used as electron donors in bioreduction of Fe(III. Ferrous ions and fresh ferrous or ferric hydroxides that are produced after iron bioreduction and (biooxidation adsorb and precipitate diferent negatively charged molecules, for example chlorinated compounds of sucralose production wastewater or other halogenated organics, as well as phenols, organic acids, phosphate, and sulphide. Reject water (return liquor from the stage of sewage sludge dewatering on municipal wastewater treatment plants represents from 10 to 50% of phosphorus load when being recycled to the aeration tank. BioIronTech process can remove/recover more than 90% of phosphorous from this reject water thus replacing the conventional process of phosphate precipitation by ferric/ferrous salts, which are 20–100 times more expensive than iron ore, which is used in BioIronTech process. BioIronTech process can remarkably improve the aerobic and anaerobic treatments of municipal and industrial wastewaters, especially anaerobic digestion of lipid- and sulphate-containing food-processing wastewater. It

Environmental association of iron minerals and iron concentrations ...

African Journals Online (AJOL)

Environmental association of iron (Fe) minerals and Fe concentrations in soils close to the Kgwakgwe Mn oxide ore abandoned mine, Botswana are investigated in this study. Four hundred soil samples were obtained from a 4 km2 area close to the abandoned mine. The Fe minerals in the soil samples were identified by ...

X-ray analysis in the steel industry

International Nuclear Information System (INIS)

Bourke, T.; Turner, K.

1999-01-01

Full text: The steel industry makes extensive use of X-ray analysis at all stages of the steelmaking process. XRF and XRD techniques, together with the associated techniques of electron probe microanalysis and electron microscopy are key tools for exploration and mine site and process development where detailed grade and mineralogical data is required. In production X-ray analysis is used to monitor and control: mine product grade (eg iron ore, coal and other raw materials), steel making production processes (eg iron ore sinter, incoming raw materials), waste products (eg coal watery refuse, slags) and final products (eg paint coatings, customer complaints). The demands put on X-ray analysis by the Steel Industry are severe. Iron ore mining and steelmaking is a continuous process, hence instrumentation has to be robust and reliable. In addition, with ever tightening environmental controls there is an increasing demand for trace heavy element analysis in both raw and waste materials. Copyright (1999) Australian X-ray Analytical Association Inc

Method for Transformation of Weakly Magnetic Minerals (Hematite, Goethite into Strongly Magnetic Mineral (Magnetite to Improve the Efficiency of Technologies for Oxidized Iron Ores Benefication

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Ponomarenko, O.

2015-03-01

Full Text Available A new method for relatively simple transformation of weakly magnetic minerals (goethite (α-FeOOH and hematite (α-Fe2O3 into strongly magnetic mineral (magnetite (Fe3O4 was developed. It was shown, that transformation of structure and magnetic characteristics of go ethite and hematite are realized in the presence of starch at relatively low temperatures (in the range of 300—600 °С. Obtained results open up new possibilities for development of effective technologies for oxidized iron ore beneficiation.

Effect of properties of iron compounds on the catalytic activity in direct coal liquefaction; Tetsu kagobutsu no keitai to sekitan ekika kassei

Energy Technology Data Exchange (ETDEWEB)

Kaneko, T.; Tazawa, K. [Mitsubishi Chemical Corp., Tokyo (Japan); Shimasaki, K. [Kobe Steel Ltd. (Japan)

1998-08-20

When considering merchandising scale of the coal liquefaction process, it is a preliminary condition that metal used for its catalyst is rich in resource volume, cheap in production cost, without pollution, and so forth, and application of cheap iron ore and ferrous compounds to disposable catalyst is desired. As liquefaction activity of the iron ore was hitherto improved by its micro crushing, its mechanical crush had a limit of about 2 {mu}m in mean particle diameter. However, together with recent crushing technique, crushers with high performance were developed, and then micro crushing by sub-micron became possible industri8ally even for iron ore. In this study, three kinds of Australian iron ores such as limonite of ferric hydroxide type iron ore, pyrite of ferrous sulfide type, and hematite of ferric oxide type were micro crushed to examine coal liquefaction activity and hydrogenation reaction activity of 1-methyl naphthalene (1-MN) and also relationship between properties and activity of catalyst for the latter before and after reaction. 11 refs., 8 figs., 5 tabs.

Prospecting For Magnetite Ore Deposits With A Innovative Sensor's of Unique Fundamentally New Magnetometer.

Science.gov (United States)

Emelianenko, T. I.; Tachaytdinov, R. S.; Sarichev, V. F.; Kotov, B. V.; Susoeva, G. N.

measurement point. The result is often misleading as an intense magnetic anomaly may be registered in a place where is no ore, and vice versa. Such false anomalies and maps may serve as the only guide in iron ore prospecting. The reserves' forecast based on such magnetic maps are also false as they may yield figures exceeding the actual reserves by tens or even hundreds of times. The existing magnetometres are often insufficiently sensitive and incapable of detecting small commercial processable ore bodies with a weak magnetic anomaly (less than 0.1% of the Earth's field). As regards new large iron ore deposits with strong anomalies, the probabilities of encountering them nowadays are becoming increasingly smaller. Confidence in the good performance and the advantages of the new magnetometres patented by the Magnitogorsk Iron and Steel Works is based on the following considerations: The anomalies' magnetic field is several times stronger than the magnetic field of the Earth; To cite two historical instances, the Sokolovskoye ore deposit in Kazakhstan was discovered in 1949 not by prospectors but by a civil aviation pilot, M.Surgutanov, using an ordinary airplane compass. The Kursk Magnetic Anomaly was discovered in 1778 by Professor I.Inozemtsev using a piece of ore hung on a string. The magnetometres patented by the MMK team, are based on the electromagnetism laws of Ampere, Ohm, Weber, Maxwell and Tesla. The history of magnetic prospecting can be divided into three periods, each of them preceded by a revolution of sorts. The first one occurred in 1910 when the German scientist Schmidt developed an optic mechanical magnetometre which came to be known in Russia as M-2 or "Fanzelau". The second revolution came about in 1936 with the invention by the Russian scientist A.Logachov of an AM-9L aeromagnetometre. The third revolution happened in 1953 when Pickard in the Unuted States (and Tsyrell in 1957 in the Soviet Union) invented a proton and quantum magnetometre. But, having

Spectrophotometric Determination of Thorium in Low Grade Minerals and Ores

Energy Technology Data Exchange (ETDEWEB)

Arnfelt, A L; Edmundsson, I

1960-08-15

The following method is intended for the determination of microgram quantities of thorium in samples of minerals and ores. The mineral sample is decomposed by repeated sintering with sodium peroxide. After digestion with water thorium peroxide hydrate is recovered by centrifugation and dissolved in hydrochloric acid. Thorium is determined spectrophotometrically with naphtarson after its separation from metals forming chloro complexes which are adsorbed on a strongly basic anion exchange resin. Interferences from a few different ions have been studied. The time required for the analysis of one sample is about 4 hours, when analysing 12 samples simultaneously

Spectrophotometric Determination of Thorium in Low Grade Minerals and Ores

International Nuclear Information System (INIS)

Arnfelt, A.L.; Edmundsson, I.

1960-08-01

The following method is intended for the determination of microgram quantities of thorium in samples of minerals and ores. The mineral sample is decomposed by repeated sintering with sodium peroxide. After digestion with water thorium peroxide hydrate is recovered by centrifugation and dissolved in hydrochloric acid. Thorium is determined spectrophotometrically with naphtarson after its separation from metals forming chloro complexes which are adsorbed on a strongly basic anion exchange resin. Interferences from a few different ions have been studied. The time required for the analysis of one sample is about 4 hours, when analysing 12 samples simultaneously

Application of spark plasma sintering for fabricating Nd-Fe-B composite

Science.gov (United States)

Sivkov, A. A.; Ivashutenko, A. S.; Lomakina, A. A.

2015-10-01

Constant magnets are applied in such fields as electric equipment and electric generators with fixed rotor. Rare earth metal neodymium is well known as promising material. Production of magnets by sintering three elements (neodymium, iron and boron) is one the most promising methods. But there are difficulties in choosing the right temperature for sintering and further processing. Structure and properties of the product, consisted of rare earth metals, was analyzed. X-ray analysis of the resulting product and the finished constant magnet was performed. Vickers microhardness was obtained.

The need for iron ore and the environmental Kuznets curve. Spain; 0176 La necesidad del mineral de hierro y la curva de Kuznets ambiental. El caso espanol

Energy Technology Data Exchange (ETDEWEB)

Torre de Palacios, L. de la

2011-07-01

Firstly, the environmental position of Spain with regard to steel consumption is defined according to the Kuznets curve (EKC) hypothesis. It is essential to undertake a complete environmental assessment of Spanish iron-ore consumption, to study the different steelmaking processes at this moment, emphasising the contribution of the high electric arc furnace. The use of recycled scrap, together with lower CO{sub 2} emissions, have succeeded in establishing Spain in a good environmental situation. (Author) 30 refs.

New technologies and raw materials for iron and steel making

Energy Technology Data Exchange (ETDEWEB)

Holappa, L. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Metallurgy

1998-07-01

The current steelmaking is still mainly based on two alternatives routes. The first one is ore based production route via reduction in blast furnaces (BF) to produce carbon-rich hot metal which is then oxidised in basic oxygen converter process (BOF) to crude steel, then refined and alloyed in several secondary (ladle) metallurgical operations to its final composition, further followed by continuous casting and rolling operations. The second main steelmaking route starts from steel scrap as the main raw material, melting of scrap in electric furnaces to crude steel, the subsequent stages being corresponding to those in ore based steelmaking. Both these processes represent well-established and highly developed technologies. However, they have some drawbacks. Blast furnace process needs sinter or pellets and coke as its raw materials. That means erection of large integrates with high investment costs in the production units themselves as well as to avoid severe environmental issues. Scrap-based steelmaking is ideal from the viewpoint of recycling, but it is limited by the scrap availability and quality problems encountered by the noticeable metallic impurities in purchase scrap. Direct reduction of iron ore in solid state to produce direct reduced iron (DRI) has its roots in the early ironmaking history but was firstly commercialised on a modern concept at the end of the 1960's when the first Midrex installation was run into operation. Most of the DR-processes utilise natural gas as the reducing agent but also some processes utilising coal have been introduced and are used in industrial scale. The oil crises in the 1970's slowed down the progress of DRI production but during the last 15 years the production has steadily grown being nowadays about 35 Mton/year. That corresponds to roughly 10 pct of the total solid material input into the world steel production. No doubt, the growth will continue in the near future as well. Quite recently, a new process

The search for asbestos within the Peter Mitchell Taconite iron ore mine, near Babbitt, Minnesota.

Science.gov (United States)

Ross, Malcolm; Nolan, Robert P; Nord, Gordon L

2008-10-01

Asbestos crystallizes within rock formations undergoing intense deformation characterized by folding, faulting, shearing, and dilation. Some of these conditions have prevailed during formation of the taconite iron ore deposits in the eastern Mesabi Iron Range of Minnesota. This range includes the Peter Mitchell Taconite Mine at Babbitt, Minnesota. The mine pit is over 8 miles long, up to 1 mile wide. Fifty three samples were collected from 30 sites within areas of the pit where faulting, shearing and folding occur and where fibrous minerals might occur. Eight samples from seven collecting sites contain significant amounts of ferroactinolite amphibole that is partially to completely altered to fibrous ferroactinolite. Two samples from two other sites contain ferroactinolite degraded to ropy masses of fibers consisting mostly of ferrian sepiolite as defined by X-ray diffraction and TEM and SEM X-ray spectral analysis. Samples from five other sites contain unaltered amphiboles, however some of these samples also contain a very small number of fiber bundles composed of mixtures of grunerite, ferroactinolite, and ferrian sepiolite. It is proposed that the alteration of the amphiboles was caused by reaction with water-rich acidic fluids that moved through the mine faults and shear zones. The fibrous amphiboles and ferrian sepiolite collected at the Peter Mitchell Mine composes a tiny fraction of one percent of the total rock mass of this taconite deposit; an even a smaller amount of these mineral fragments enter the ambient air during mining and milling. These fibrous minerals thus do not present a significant health hazard to the miners nor to those non-occupationally exposed. No asbestos of any type was found in the mine pit.

Development document for the effluent limitations and guidelines for the ore mining and dressing point source category. Volume I. Final report

International Nuclear Information System (INIS)

Jarrett, B.M.; Kirby, R.G.

1978-07-01

To establish effluent limitation guidelines and standards of performance, the ore mining and dressing industry was divided into 41 separate categories and subcategories for which separate limitations were recommended. This report deals with the entire metal-ore mining and dressing industry and examines the industry by ten major categories: iron ore; copper ore; lead and zinc ores; gold ore; silver ore; bauxite ore; ferroalloy-metal ores; mercury ores; uranium, radium and vanadium ores; and metal ores, not elsewhere classified ((ores of antimony, beryllium, pltinum, rare earths, tin, titanium, and zirconium). The subcategorization of the ore categories is based primarily upon ore mineralogy and processing or extraction methods employed; however, other factors (such as size, climate or location, and method of mining) are used in some instances. With the best available technology economically achievable, facilities in 21 of the 41 subcategories can be operated with no discharge of process wastewater to navigable waters. No discharge of process wastewater is also achievable as a new source performance standard for facilities in 21 of the 41 subcategories

Determination of metallic iron in sponge-iron

International Nuclear Information System (INIS)

Mueller, C.S.

1974-01-01

The amount of metallic iron in sponge-iron is a parameter of major interest in the evaluation of the performance of the ore-reduction process and in the determination of the composition of the load of the electric furnace used to produce the steel. Moessbauer effect offers the promise of a simple and elegant analysis method, capable of competing directly with the usually time-consuming chemical procedures. The applicability of the method is considered and the possible sources of error are analyzed, resulting in the design of an instrument that is reasonably accurate and simple to use. Detailed electronic circuity required to produce a direct-reading digital instrument is shown [pt

Manufacturing of concrete with residues from iron ore exploitation using the technology of radioactive waste cementation

Energy Technology Data Exchange (ETDEWEB)

Versieux, Juniara L.; Lameiras, Fernando S.; Tello, Cledola Cassia Oliveira de, E-mail: juniarani@gmail.com, E-mail: fsl@cdtn.br, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nucelar (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2015-07-01

Radioactive wastes from various segments of economy are immobilized by cementation, because of availability and widespread use in civil construction of cement. New cementitious materials are developed in CDTN using mining residues based on cementing techniques of radioactive wastes. Special procedures were developed to obtain concrete with the use of super plasticizers in which natural sand was totally replaced by mining residues. The motivation for this research is the exploration of banded iron formations (BIF) as iron ore in 'Quadrilatero Ferrifero' of Minas Gerais, where huge amounts of residues are generated with great concern about the environmental sustainability and safety of dams for residue storage. The exploitation of river sand causes many negative impacts, which leads to interest in its replacement by another raw material in mortar and concrete manufacturing. The use of BIF mining residues were studied for manufacturing of concrete pavers to contribute to reducing the impact caused by extraction of natural sand and use of mining residues. Previously developed procedures with total replacement of natural sand for mining residues were modified, including use of gravel to obtain pavers with improved properties. Four different mixtures were tested, in which the proportion of gravel and super plasticizer was varied. Monitored properties of pavers, among others, were compression resistance, water absorption, and void volume. With addition of gravel, the pavers had higher void index than those made only with mortar, and higher resistance to compression after 28 days of curing (an average of 18MPa of those made with mortar to 24MPa of those made with concrete). (author)

Manufacturing of concrete with residues from iron ore exploitation using the technology of radioactive waste cementation

International Nuclear Information System (INIS)

Versieux, Juniara L.; Lameiras, Fernando S.; Tello, Cledola Cassia Oliveira de

2015-01-01

Radioactive wastes from various segments of economy are immobilized by cementation, because of availability and widespread use in civil construction of cement. New cementitious materials are developed in CDTN using mining residues based on cementing techniques of radioactive wastes. Special procedures were developed to obtain concrete with the use of super plasticizers in which natural sand was totally replaced by mining residues. The motivation for this research is the exploration of banded iron formations (BIF) as iron ore in 'Quadrilatero Ferrifero' of Minas Gerais, where huge amounts of residues are generated with great concern about the environmental sustainability and safety of dams for residue storage. The exploitation of river sand causes many negative impacts, which leads to interest in its replacement by another raw material in mortar and concrete manufacturing. The use of BIF mining residues were studied for manufacturing of concrete pavers to contribute to reducing the impact caused by extraction of natural sand and use of mining residues. Previously developed procedures with total replacement of natural sand for mining residues were modified, including use of gravel to obtain pavers with improved properties. Four different mixtures were tested, in which the proportion of gravel and super plasticizer was varied. Monitored properties of pavers, among others, were compression resistance, water absorption, and void volume. With addition of gravel, the pavers had higher void index than those made only with mortar, and higher resistance to compression after 28 days of curing (an average of 18MPa of those made with mortar to 24MPa of those made with concrete). (author)

Mineralogical test as a preliminary step for metallurgical proses of Kalan ores

International Nuclear Information System (INIS)

Affandi, K.

1998-01-01

Mineralogical tests as a preliminary step for hydrometallurgy of Kalan ores, including Eko Remaja and Rirang have been carried out to identify the elements and minerals content which affect the metallurgical process, especially the leaching and purification of uranium. Mineralogical tests have been done by means of radioactive and radioluxugraph tests to identify radioactive minerals; thin specimen analysis, Scanning Electron Microscopy (SEM) to identify elements and morphology, EPMA to analyse qualitatively the elements, X-ray Diffractometer (XRD) to identify of minerals content; and X-ray Fluorescence (XRF) and chemical analyses to determine total elements qualitatively and quantitatively. The experimental results show that the Eko Remaja ores contain uraninite and brannerite, iron and titan oxides, sulfides, phosphates and silicates minerals, while the Rirang ores contain uraninite, monazite and molybdenite

Research on Laser Micro Polishing of SLS Technology Sintered Iron-Based Powder Surface

OpenAIRE

Gerda Vaitkūnaitė; Vladislav Markovič; Olegas Černašėjus

2015-01-01

The article analyzes laser micro polishing of 1.2083 steel samples produced applying selective laser sintering (SLS) method. The study has evaluated the distribution of the shape, size and temperature of the laser beam treated area in the surface layer of sintered and laser polished samples. Experimental tests have shown the impact of the technical parameters of laser micro polishing on the width and hardness of the impact zone of the treated sample. The microstructure analysis of laser treat...

Sintering and densification; new techniques: sinter forging

International Nuclear Information System (INIS)

Winnubst, A.J.A.

1998-01-01

In this chapter pressure assisted sintering methods will be described. Attention will mainly be paid to sinter forging as a die-wall free uniaxial pressure sintering technique, where large creep strains are possible. Sinter forging is an effective tool to reduce sintering temperature and time and to obtain a nearly theoretically dense ceramic. In this way grain size in tetragonal zirconia ceramics can be reduced down to 100 nm. Another important phenomenon is the reduction of the number density and size of cracks and flaws resulting in higher strength and improved reliability, which is of utmost importance for engineering ceramics. The creep deformation during sinter forging causes a rearrangement of the grains resulting in a reduction of interatomic spaces between grains, while grain boundary (glassy) phases can be removed. The toughness and in some cases the wear resistance is enhanced after sinter forging as a result of the grain-boundary-morphology improvement. (orig.)

Processing and Properties of Distaloy Sa Sintered Alloys with Boron and Carbon

Directory of Open Access Journals (Sweden)

Karwan-Baczewska J.

2015-04-01

Full Text Available Prealloyed iron-based powders, manufactured in Höganäs Company, are used in the automotive parts industry. The properties and life time of such sintered parts depend, first of all, on their chemical composition, the production method of the prealloyed powder as well as on the technology of their consolidation and sintering. One of simpler and conventional methods aimed at increasing the density in sintered products is the process of activated sintering, performed, for example, by adding boron as elementary boron powder. Under this research project obtained were novel sintered materials, based on prealloyed and diffusion bonded powder, type: Distaloy SA, with the following chemical composition: Fe-1.75% Ni-1.5%Cu- 0.5%Mo with carbon (0.55%; 0.75% and boron (0.2%, 0.4% and 0.6%. Distaloy SA samples alloyed with carbon and boron were manufactured by mixing powders in a Turbula mixer, then compressed using a hydraulic press under a pressure of 600 MPa and sintered in a tube furnace at 1473 K, for a 60 minute time, in the hydrogen atmosphere. After the sintering process, there were performed density and porosity measurements as well as hardness tests and mechanical properties were carried out, too. Eventually, analyzed was the effect of boron upon density, hardness and mechanical properties of novel sintered construction parts made from Distaloy SA powder.

Ore controlling oxidized zonation epigenetic uranium-coal deposits and regularities in lignite transformations

International Nuclear Information System (INIS)

Uspenskij, V.A.; Kulakova, Ya.M.

1982-01-01

Complex of analytical methods was used to study epigenetic transformations in uranium-coal ore manifestation. To clarify the principle scheme of oxidized zonation in coals the materials, related to three similar objects were used. When comparing obtained epigenetic column with columns of similar ore objects the principle scheme of oxidized epigenetic zonation for ancient infiltration uranium-coal deposits was specified; general regularities of eignite transformations and characteristics of profile distribution of uranium and accessory metal zonations were revealed. Infiltration processes, proceeded in coal measureses, formed the steady epigenetic oxidized zonation: O - zone of barren unoxidized coals, 1 - zone of ore-bearing unoxidized coals, 2 - zone of weakly ore-bearing oxidized coals, 3 - zone of oxidized terrigenous rocks with zonules of development of yellow and red iron hydroxides. Capacities of some zones and zonules reflect the intensity and duration of ore-forming processes. Distribution of U and accessory elements obeys completely epigenetic zonation. It is assumed, that ancient infiltration uranium-coal deposits formed due to weakly uranium-bearing oxygen-containing waters

Evaluation of Social Performance and Related Factors in Iranian Central Iron Ore company workers

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Gholamhossein Halvani

2013-01-01

Full Text Available Introduction: Psychological and social health is the main problems of workers population, which can increase productivity at work and physical and mental health and provide or decline in these aspects. Materials and Methods: this study was descriptive and crosses - sectional and has been performed on 388 Iranian central iron ore company workers. The tool of study was standard GHQ-28 question are that has been measured under social performance scale. Results: 49.3 and 49 percent of the people have favorable and average score from the state of the social function condition and 1.8 percent of people have severe social dysfunction and besides the employees have less work experienced that have more social dysfunction and there is a relationship between the P = 0.026. With satisfaction with the status of social dysfunction (P = 0 and with the consent of the income (P = 0 there is significant relationship. Conclusion: In this study, a significant percentage of mineworkers were not in good condition from health, social functioning. It reveals the importance of addressing health issues and vulnerable working class, Intervention studies conducted by employers to improve job satisfaction and increased income and received social support from him, can increase the health indicators related to the body and mind.

Geoscientific investigations in the abandoned iron ore mine Konrad for safe disposal of certain radioactive waste categories

International Nuclear Information System (INIS)

Brewitz, W.

1980-01-01

Besides the disposal of high-active waste in a salt formation the national policy of the Federal Republic of Germany provides for a second underground storage facility for non-α-emitting and low-active waste. Due to the short decay times of such wastes the demands made on the geological barrier are in some respect different, in particular as regards long-term stability and impermeability to liquids. Within the 1000-year-phase all wastes will have reached a concentration with a content of radionuclides far below that of a uranium deposit. The abandoned iron ore mine Konrad (Lower Saxony) has some exceptional geological features which make it a very good choice for a radioactive waste repository. The mine is 1200 m deep. Stopes and galleries are extremely dry. The hanging rock formations are mainly claystones. The mining installations are of modern design. The geological, hydrogeological and geophysical investigations have to examine in detail the covering claystone formations for their extension and mineralization, the origin and the age of the mine's seepage water as well as the mechanical stability of the underground cavities during and after the operational period. Via radiological investigations a catalogue of various low-active waste types, the waste volumina and the total activities accumulating over a period of 30 years is being established. For a safety assessment the hazard indices of a uranium ore deposit containing 0.2 wt% U 3 O 8 and a waste repository corresponding to the above figures were compared. The research programme has not been terminated yet since it is being financed by the Bundesminister fuer Forschung und Technologie (BMFT) of the Federal Republic of Germany until the end of 1981

Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

Science.gov (United States)

Deevi, Seetharama C.; Lilly, Jr., A. Clifton; Sikka, Vinod K.; Hajaligol, Mohammed R.

2000-01-01

A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

Digestion of Alumina from Non-Magnetic Material Obtained from Magnetic Separation of Reduced Iron-Rich Diasporic Bauxite with Sodium Salts

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Guanghui Li

2016-11-01

Full Text Available Recovery of iron from iron-rich diasporic bauxite ore via reductive roasting followed by magnetic separation has been explored recently. However, the efficiency of alumina extraction in the non-magnetic materials is absent. In this paper, a further study on the digestion of alumina by the Bayer process from non-magnetic material obtained after magnetic separation of reduced iron-rich diasporic bauxite with sodium salts was investigated. The results indicate that the addition of sodium salts can destroy the original occurrences of iron-, aluminum- and silicon-containing minerals of bauxite ore during reductive roasting. Meanwhile, the reactions of sodium salts with complex aluminum- and silicon-bearing phases generate diaoyudaoite and sodium aluminosilicate. The separation of iron via reductive roasting of bauxite ore with sodium salts followed by magnetic separation improves alumina digestion in the Bayer process. When the alumina-bearing material in bauxite ore is converted into non-magnetic material, the digestion temperature decreases significantly from 280 °C to 240 °C with a nearly 99% relative digestion ratio of alumina.

Synthesis and characterization of niobium and iron phosphate glasses for U3O8 immobilization

International Nuclear Information System (INIS)

Ghussn, Luciana

2005-01-01

Niobium and iron phosphate glasses were produced by melting inorganic compound mixtures in electric furnaces and microwave ovens. The chemical durability was compared among niobium phosphate glasses produced by both processes, and equivalent results were obtained. Leaching tests were also performed to compare the chemical durability among monolithic glass blocks and sintered glasses. The glass transition, crystallization and melting temperatures as well the Hruby parameter (K H ) and the activation energy for crystallization were determined from differential thermal analysis of niobium phosphate glasses produced in electric furnaces. Niobium phosphate glasses are thermally more stable (K H =0.82 +- 0.04) than iron phosphate glasses (K H = 0.42 +- 0.03). Sintered glasses were produced from particles with different particle size distributions and sintering temperatures in the range of 720 - 800 deg C for niobium phosphate and 530 - 680 deg C for iron phosphate glasses. The sintering process was suitable because a glass with composition 37P 2 O 5 -23K 2 O-40Nb 2 O 5 showing leaching rate of 10 -6 g.cm -2 .d -1 , 99 % of the monolithic density and none crystalline phases was obtained. This glass only crystallizes itself after re heating at temperatures above 800 deg C , showing two crystalline phases identified as KNb 3 O 8 e K 3 NbP 2 O 9 . The activation energies for crystallization are 496 +- 7 kJ/mol and 513 +- 14 kJ/mol. Niobium phosphate sintered glasses are better densified than sintered iron phosphate glasses. The leaching rate of sintered glasses that show open porosity is higher than monolithic glass blocks. This effect is related to an increase of the surface area associated to open porous and, a correction of the value of the surface area used to calculate the leaching rate is required. A model was proposed based on the surface area of spherical porous to take in account that effect. Even after correcting the surface area, the leaching rates of sintered

Control of Rock Mechanics in Underground Ore Mining

Science.gov (United States)

Golik, V. I.; Efremenkov, A. B.

2017-07-01

Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

Acid curing and baking of bastnasite ore and concentrate

International Nuclear Information System (INIS)

Topkaya, Y.; Akkurt, S.

1998-01-01

Full text: In this study, the hydrometallurgical evaluation of a rare earth ore as well as a concentrate obtained from this was done at laboratory. For the mentioned study, a bastnasite type rare earth ore located in Beylikahir in Turkey was used. The total rare earth oxide (REO) content of the deposit was estimated to be 1 million tons with an average concentration of 3.42%REO. The rare earths were contained in bastnasite mineral. The other constituents of the ore were calcium fluoride (52.5%), barite (25.4%), calcite (2.8%) and minor amounts of thorium, iron, manganese, etc. The bastnasite mineral occurred either as cement material between fluoride and barite particles or as intimately associated with these minerals. The rare earth elements were enriched considerably in sub-sieve sizes. After extensive research about the physical concentration of this ore, two different metallurgical routes were followed for the extraction of REE from the ore itself or the preconcentrate obtained by attrition scrubbing and desliming by cyclones. In order to increase the grade of the concentrate, upgrading of the preconcentrate by multigravity was also tried. The two metallurgical routes tested were: Sulphuric acid curing and water leaching; Sulphuric acid baking and subsequent water leaching. The results of the leaching experiments were found to be quite promising. Leach recoveries up to 90% were easily obtainable. In the case of acid baking, hydrofluoric acid recover as a by-product was also possible

Effects of sintering atmosphere on the physical and mechanical properties of modified BOF slag glass

Science.gov (United States)

Dai, Wen-bin; Li, Yu; Cang, Da-qiang; Zhou, Yuan-yuan; Fan, Yong

2014-05-01

This study proposes an efficient way to utilize all the chemical components of the basic oxygen furnace (BOF) slag to prepare high value-added glass-ceramics. A molten modified BOF slag was converted from the melting BOF slag by reducing it and separating out iron component in it, and the modified BOF slag was then quenched in water to form glasses with different basicities. The glasses were subsequently sintered in the temperature range of 600-1000°C in air or nitrogen atmosphere for 1 h. The effects of different atmospheres on the physical and mechanical properties of sintered samples were studied by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) and by conducting experiment on evaluating the sintering shrinkage, water absorption and bulk density. It is found that the kinetics of the sintering process is significantly affected by sintering atmosphere. In particular, compared with sintering in air atmosphere, sintering in N2 atmosphere promotes the synergistic growth of pyroxene and melilite crystalline phases, which can contribute to better mechanical properties and denser microstructure.

Sintering of micro-trusses created by extrusion-3D-printing of lunar regolith inks

Science.gov (United States)

Taylor, Shannon L.; Jakus, Adam E.; Koube, Katie D.; Ibeh, Amaka J.; Geisendorfer, Nicholas R.; Shah, Ramille N.; Dunand, David C.

2018-02-01

The development of in situ fabrication methods for the infrastructure required to support human life on the Moon is necessary due to the prohibitive cost of transporting large quantities of materials from the Earth. Cellular structures, consisting of a regular network (truss) of micro-struts with ∼500 μm diameters, suitable for bricks, blocks, panels, and other load-bearing structural elements for habitats and other infrastructure are created by direct-extrusion 3D-printing of liquid inks containing JSC-1A lunar regolith simulant powders, followed by sintering. The effects of sintering time, temperature, and atmosphere (air or hydrogen) on the microstructures, mechanical properties, and magnetic properties of the sintered lunar regolith micro-trusses are investigated. The air-sintered micro-trusses have higher relative densities, linear shrinkages, and peak compressive strengths, due to the improved sintering of the struts within the micro-trusses achieved by a liquid or glassy phase. Whereas the hydrogen-sintered micro-trusses show no liquid-phase sintering or glassy phase, they contain metallic iron 0.1-2 μm particles from the reduction of ilmenite, which allows them to be lifted with magnets.

Research on Laser Micro Polishing of SLS Technology Sintered Iron-Based Powder Surface

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Gerda Vaitkūnaitė

2015-03-01

Full Text Available The article analyzes laser micro polishing of 1.2083 steel samples produced applying selective laser sintering (SLS method. The study has evaluated the distribution of the shape, size and temperature of the laser beam treated area in the surface layer of sintered and laser polished samples. Experimental tests have shown the impact of the technical parameters of laser micro polishing on the width and hardness of the impact zone of the treated sample. The microstructure analysis of laser treated and untreated areas of the material has been made.

Report of year 2000 version on basic study for promotion of joint implementation. Feasibility study on energy saving at Anshan Iron and Steel Group Complex

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

In order to promote the COP3 joint implementation, a survey was conducted in fiscal 1999 at Anshan Iron and Steel Group Complex in China. The complex is the leading iron and steel maker in China. The unit requirement for energy consumption per ton of crude ore is 7.00 Gcal, which is close to 1.4 times that in Japan. The feasibility study has discussed and planned modification of ignition furnace facilities and waste heat recovery in the sintering process, top-pressure gas recovery at uniform pressure, and top-pressure recovery turbine (TRT) in the blast furnace, based on the locally available data and surveys. The modification of the ignition furnace in the sintering process resulted in reduction of fuel consumption of 578.0 TJ/year in the facility No. 2, and 718.9 TJ/year in the facility No. 3. The amount of electric power generated by the TRT is 121.13 GWh/year assuming the annual blast furnace operation factor of 90%. This can be converted to the heat quantity of 1,370 TJ/year. The top-pressure gas recovery amount is 163 TJ/year when converted to the heat quantity. Annual CO2 reduction amounted to 15,373 tons. The profitability was discussed by using the present worth method. Because of coal price being low and the energy unit price being low in China, it was revealed that the profitability at the private sector level could not be achieved. (NEDO)

Development of a process with reduced energy consumption and environmental pollution in the production of solid, thermostable iron ore agglomerates. Final report; Entwicklung eines Verfahrens zur Senkung des Energiebedarfs und der Umweltbelastung bei der Herstellung von festen und thermostabilen Eisenerzagglomeraten. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Naundorf, W.; Trommer, D. [TU Bergakademie Freiberg (Germany); Guenter, H. [Koeppern Aufbereitungstechnik GmbH und Co. KG, Markkleeburg (Germany)

2002-06-01

In iron ore reduction with carbon, as a rule the ores are processed into stable and thermally stable agglomerates via emission-intensive processes, e.g. pelleting and combustion. This project aimed at the development of a process that avoids these problems, e.g. by agglomerating fine ores with binders and without emissions. [German] Bei der Reduktion von Eisenerz mit Kohlenstoff werden die Erze in der Regel vor dem Einsatz in den Reduktionsofen mit hohem Aufwand an Technik und Energie durch emissionsintensive Prozesse in transport- und thermofeste Agglomerate ueberfuehrt (Pelletier- und Brennprozess). Es ist das Ziel des Projektes, eine Verfahrensloesung ohne diese Nachteile zu entwickeln. Erfolgversprechend wird eine Verfahrenstechnik angesehen, bei der die Feinerze unter Zusatz von Bindestoffen ohne Emissionen agglomeriert werden. (orig.)

Geology, Geochemistry and Ground Magnetic Survey on Kalateh Naser Iron Ore Deposit, Khorasan Jonoubi Province

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Saeed Saadat

2017-02-01

Full Text Available Introduction Ground magnetometer surveys is one of the oldest geophysical exploration methods used in identifying iron reserves. The correct interpretation of ground magnetic surveys, along with geological and geochemical data will not only reduce costs but also to indicate the location, depth and dimensions of the hidden reserves of iron (Robinson and Coruh, 2005; Calagari, 1992. Kalateh Naser prospecting area is located at 33° 19َ to 33° 19ََ 42" latitude and 60° 0' to 60° 9َ 35" longitude in the western side of the central Ahangaran mountain range, eastern Iran (Fig.1. Based on primary field evidences, limited outcrops of magnetite mineralization were observed and upon conducting ground magnetic survey, evidence for large Iron ore deposits were detected (Saadat, 2014. This paper presents the geological and geochemical studies and the results of magnetic measurements in the area of interest and its applicability in exploration of other potential Iron deposits in the neighboring areas. Materials and methods To better understand the geological units of the area, samples were taken and thin sections were studied. Geochemical studies were conducted through XRF and ICP-Ms and wet chemistry analysis. The ground magnetic survey was designed to take measurements from grids of 20 meter apart lines and 10 meter apart points along the north-south trend. 2000 points were measured during a 6-day field work by expert geophysicists. Records were made by Canadian manufactured product Magnetometer Proton GSM19T (Fig. 2. Properties of Proton Magnetometer using in magnetic survey in Kalateh Naser prospecting area is shown in Table 1. Total magnetic intensity map, reduced to pole magnetic map, analytic single map, first vertical derivative map and upward continuation map have been prepared for this area. Results The most significant rock units in the area are cretaceous carbonate rocks (Fig. 3. The unit turns to shale and thin bedded limestone in the

Chemical Degradation and Processes of Erosion of Post-Mine Territories After Mining Exploration of Iron Ore

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Agnieszka Pusz

2017-11-01

Full Text Available The subjects of this study were uncultivated mining waste heaps which are remnants of the territories abandoned after the exploration of iron ore. The aim of this analysis was the assessment of the influence of these objects on the soil located in the nearest surroundings, as well as estimation of the level of their degradation. It was ascertained that direct geomechanical degradation exists in the examined object, which is connected with soil profile destruction in consequence of transformation of hitherto existing geomorphological conditions, deformation of natural shape of territory, density of soil levels and deformation of the spatial layout. As a result of the examination, it was pointed out that chemical degradation as well as degradation of ecological structure occur on the analyzed territory. Progressing processes of water erosion on the side of waste heap are the consequence of improperly profiled, steep slopes causing the uncontrolled flow of rainwater, lack of flora and dense, micrograiny structure of soils which prevents the effective infiltration of water. Penetration of water into the ground causes the creation of channels which, in dry periods, can become additional pathways for the possible landslides.

The effect of human resource practices on psychological contracts at an iron ore mining company in South Africa

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Caren B. Scheepers

2011-08-01

Full Text Available Orientation: Human resource practices influence the psychological contract between employee and employer and, ultimately, organisational performance. Research purpose: The objective of this study was to examine the effect of human resource practices on the types of psychological contracts in an iron ore mining company in South Africa empirically. Motivation for the study: Although there have been a number of conceptual studies on the effect of human resource practices on psychological contracts, there has been no effort to synthesise the links between these contracts and various human resource practices systematically. This study endeavoured to provide quantitative evidence to verify or refute conceptual studies on this relationship. Its findings could inform human resource strategies and, ultimately, the prioritisation of human resource practices to improve the cost-effective allocation of resources. Research design, approach and method: The researchers administered two questionnaires. These were Rousseau’s Psychological Contract Inventory (2000 and the Human Resource Practices Scale of Geringer, Colette and Milliman (2002. The researchers conducted the study with 936 knowledge workers at an iron ore mining company in South Africa. They achieved a 32% response rate. Main findings: The findings showed that most participants have relational contracts with the organisation. Another 22% have balanced contracts, 8% have transitional contracts whilst only 1% have transactional contracts. The study suggests that there are relationships between these psychological contracts and specific human resource practices. The study found that training and development was the most important human resource practice for developing relational and balanced contracts. Employees thought that they contributed more than their employer did to the relationship. The researchers developed a model to illustrate the influence of the various human resource practices on

Steelmaking slag beneficiation by magnetic separator and impacts on sinter quality

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Bölükbaşı Ö.S.

2014-01-01

Full Text Available Basic oxygen furnaces (BOF slag is the main problem at all iron and steel factories. About more than 6 million tons/year of BOF slag has been accumulated from the waste stockyards in Turkey. Dumps slags can be revaluated by a processing technology which makes it possible to obtain products that meet the requirements of sintering and blast furnace production. The slags with particle size of -10 mm were enriched by the magnetic separator resulting and increase in Fe grade from 18% to 33%. The use of BOF slag in sinter blend provided additional Mn, CaO, MgO and introduced a good solution to environmental problems.

Rare earth-iron-boron premanent magnets

International Nuclear Information System (INIS)

Ghendehari, M.H.

1988-01-01

This patent describes a method for producing rare earth-iron-boron permanent magnets containing added rare earth oxide, comprising the steps of: (a) mixing a particulate alloy containing at least one rare earth metal, iron, and boron with at least one particulate rare earth oxide; (b) aligning magnetic domains of the mixture in a magnetic field; (c) compacting the aligned mixture to form a shape; and (d) sintering the compacted shape

Morphological analysis and modelling of sintering and of sintered materials

International Nuclear Information System (INIS)

Jernot, Jean-Paul

1982-01-01

This research thesis addresses the study of solid phase sintering of metallic powders, and aims at describing as precisely as possible the different involved matter transport mechanisms, first by using a thermodynamic approach to sintering. Sintering diagrams are also used to determine prevailing mechanisms. The microstructure of sintered materials has been studied by using image quantitative analysis, thus by using a morphological approach to sintering. Morphological parameters allow, on the one hand, the evolution of powders during sintering to be followed, and, on the other hand, sintered products to be correctly characterised. Moreover, the author reports the study of the evolution of some physical properties of sintered materials with respect to their microstructure parameters. This leads to the development of a modelling of the behaviour of these materials [fr

A study for preparation of Ti-Fe coating by high temperature sintering method

International Nuclear Information System (INIS)

Hu Yonghai

1995-03-01

A new technology for preparation of Ti-Fe alloy coating on the steel substrate was investigated by high temperature sintering method. The pulp of titanium hydride powder was coated on the cleaned steel substrate, then heated in vacuum for desorption of hydrogen and sintered at high temperature in argon atmosphere for forming Ti-Fe alloy coating. The electron probe analysis shows a strong coherent diffusion layer formed between the elements of titanium and iron. X-ray diffraction analysis indicates that the coating consists of α-Ti, TiFe and TiFe 2 three phases. The wear resistance of the coating is twice as large as that of grey cast iron and the hardness determined can reach 7300∼7800 N/mm 2 . The coating is almost porous free. The corrosion potential increases with the time and the corrosion resistance is near to that of pure titanium. The working life of ridge-type diaphragm valve coated by Ti-Fe alloy for carbonization tower of alkali factories is five times higher than that of valve made of grey cast iron. Therefore, this new technology can be widely used in metallurgical, chemical and nuclear industries. (9 figs., 10 tabs.)

Novel Binders and Methods for Agglomeration of Ore

Energy Technology Data Exchange (ETDEWEB)

S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

2006-12-31

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

Radon risk in ore miners

International Nuclear Information System (INIS)

Beno, M.

1997-01-01

Underground workers are exposed to various clastogenic agents. One of these agents, radon, attracts attention of recent research as it causes lung cancer in the population occupationally exposed to its various concentrations especially in mine air of uranium mines or ore mines. This paper is a pilot study in which the numbers of chromosomal aberrations (CA) in lymphocytes of ore mines (Nizna Slana-iron ore, Hnusta-talc ore) located in east central Slovakia were followed and related to the lifetime underground radon exposure and to lifetime smoking. Seventy miners volunteering after an informed consent served as donors of venous blood. Twenty healthy pro-bands, age matched with the miners, which never worked underground (mostly clerks) served as donors of control blood samples. The exposure to radon and smoking has been estimated according to working-records and personal anamnesis. The findings unequivocally showed a small but statistically significant clastogenic effect of the exposure to underground environment of the mines concerned. This study has shown also a small but significant influence of smoking, which in the subgroup of miners working underground less than 1500 shifts may have acted synergically with the underground exposure. It was concluded tat: (1) Significantly higher counts of chromosomal aberrations in lymphocytes of 70 miners than in an age matched control group of 20 white-collar workers were found; (2) The higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; (3) The positive dependence of the number of chromosomal aberrations from the exposure to smoking was loose and it was expressed by significantly higher chromosomal aberrations counts in the group of miners working less than 1500 shifts underground; (4) A dependence of chromosomal aberrations counts from the exposure to radon could not be assessed. At relatively low numbers of pro-bands in subgroups it was not ruled out the confounding

Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

International Nuclear Information System (INIS)

Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

1994-03-01

The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique

Mineral Phases and Release Behaviors of As in the Process of Sintering Residues Containing As at High Temperature

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Xingrun Wang

2014-01-01

Full Text Available To investigate the effect of sintering temperature and sintering time on arsenic volatility and arsenic leaching in the sinter, we carried out experimental works and studied the structural changes of mineral phases and microstructure observation of the sinter at different sintering temperatures. Raw materials were shaped under the pressure of 10 MPa and sintered at 1000~1350°C for 45 min with air flow rate of 2000 mL/min. The results showed that different sintering temperatures and different sintering times had little impact on the volatilization of arsenic, and the arsenic fixed rate remained above 90%; however, both factors greatly influenced the leaching concentration of arsenic. Considering the product’s environmental safety, the best sintering temperature was 1200°C and the best sintering time was 45 min. When sintering temperature was lower than 1000°C, FeAsS was oxidized into calcium, aluminum, and iron arsenide, mainly Ca3(AsO42 and AlAsO4, and the arsenic leaching was high. When it increased to 1200°C, arsenic was surrounded by a glass matrix and became chemically bonded inside the matrix, which lead to significantly lower arsenic leaching.

The investigation of the microstructure and mechanical properties of ordered alominide-iron (boron) nanostructures produced by mechanical alloying and sintering

Science.gov (United States)

Izadi, S.; Akbari, Gh.; Janghorban, K.; Ghaffari, M.

In this study, mechanical alloying (MA) of Fe-50Al, Fe-49.5Al-1B, and Fe-47.5Al-5B (at.%) alloy powders and mechanical properties of sintered products of the as-milled powders were investigated. X-ray diffraction (XRD) results showed the addition of B caused more crystallite refinement compared to the B-free powders. To consider the sintering and ordering behaviors of the parts produced from cold compaction of the powders milled for 80 h, sintering was conducted at various temperatures. It was found that the sintering temperature has no meaningful effect on the long-range order parameter. The transformation of the disordered solid solution developed by MA to ordered Fe-Al- (B) intermetallics was a consequence of sintering. Also, the nano-scale structure of the samples was retained even after sintering. The microhardness of pore-free zones of the nanostructured specimens decreased by increasing the sintering temperature. Moreover, the sintering temperature has no effect on the compressive yield stress. However, the fracture strain increased by increasing the sintering temperature. The samples containing 1 at.% B showed more strain to fracture compared with the B-free and 5 at.% B samples.

Development and application of an instrument for analysis of iron in laterite ore with the characteristics needed for use in nickel production. Part of a coordinated programme on on-line X-ray and neutron techniques for industrial process control

International Nuclear Information System (INIS)

Vizoso, J.R.

1980-06-01

This document describes the performance testing of an instrument for the analysis of iron laterite ore used in the production of nickel. It proved to give satisfactory results with an error less or equal to 1% under working conditions (20 0 C - 40 0 C, 80% - 85% relative humidity)

Pilot plant studies on the extraction of antimony metal from lower grade krinj stibnite ore

International Nuclear Information System (INIS)

Rehman, W.; Riaz, M.; Ishaq, M.

2013-01-01

Antimony is a silvery white, brittle and crystalline solid which is extensively consumed in lead acid batteries, antimonial lead alloys, flame retardants and a variety of metallic products. The antimony content of commercial ores range from 5-60% and determines the method of extraction, either pyrometallurgical or hydrometallurgical. The present study focuses on pilot plant scale extraction of antimony metal from lower grade stibnite ore of Krinj (Chitral) without the use of iron scrap, thus eliminating the second step of iron removal in conventional direct reduction method. A tilting gas fired furnace with digital temperature control system and a heat recuperator was designed to optimize the operating parameters for extraction of antimony metal. Weight ratios of flux and reductant, operating time and operating temperature were optimized. Highest percentage recovery and purity were achieved using soda ash as a flux, at a temperature of 900 degree C for 2 hours. (author)

Ore-forming fluid system of bauxite in WZD area of northern Guizhou province, China

Science.gov (United States)

Cui, Tao

2017-12-01

The ore-forming fluid system of bauxite in Wuchuan-Zheng,an-Daozhen (short for WZD) Area of northern Guizhou Province was studied from the perspective of deposit formation mechanism. It was discovered that ore-forming fluids were mainly effective for transporting and leaching during the formation of bauxite. The means of transport mainly included colloidal transport, suspended transport and gravity flow transport. In the course of their leaching, fluids had a range of chemical reactions, as a result of which elements such as silicon and iron migrated downwards. In this process, properties of fluids changed as well.

Status report from USSR [Processing of Low-Grade Uranium Ores]; Doklad o sostoyanii voprosa v SSSR

Energy Technology Data Exchange (ETDEWEB)

Zefirov, A P [Gosudarstvennyj Komitet Po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moskva, Union of Soviet Socialist Republics (Russian Federation)

1967-06-15

The uranium industry for processing poor uranium ores in the USSR was established in recent years. As a result of research work institutions and enterprises in the development of this industry was provided by rapid technological advances that allowed dramatically increased productivity, reduced consumption of reagents, simplified process flow diagrams, and reduced production costs. At present, the basis for uranium industry, including and poor uranium ore deposits in the USSR are with different content valuable components (uranium, phosphorus, molybdenum, rare earth elements, thorium, iron, .. .)

Geochemistry of some banded iron-formations of the archean ...

Indian Academy of Sciences (India)

Diagenetic fluids from the sea floor sediments and river water might have played .... (in wt%) of the banded iron-formations of Archaean supracrustal belts (Iron Ore Group) of Jharkhand–Orissa region. Gandhamardan. Deo river section. H/1/1 H/1/2 H/1/3 H/1/4 H/1/5 .... indicate that contamination by pyroclastic debris.

Researches Regarding the Influence of Cu Content on Static and Dynamic Properties of Sintered Steels

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Liviu BRÂNDUŞAN

2004-02-01

Full Text Available The utilisation of iron powder in sintered steels subjected to variable loadings was confined because of their low fatigue resistance and the fact that this kind of loading is unknown for the users. Lately, a lot of effort was made to determine the fatigue behaviour and to identify new methods for improving these properties.In this paper are analyse the behaviour of elaborate materials from iron powder, DWP 200.28 with cooper addition, pressed at 600 MPa and sintered at 1120°C for 30 minutes in endogas. The cooper is add to improve the mechanical characteristics, by forming some favourable microstructures and more round pores from the material macrostructure. For this materials tensile resistance, elongation, Young modulus and the number of cycles until failure are analysed. We find that the cooper add say in a different way these properties.

Recovery of manganese from manganese oxide ores in the EDTA solution

Science.gov (United States)

Zhang, Chao; Wang, Shuai; Cao, Zhan-fang; Zhong, Hong

2018-04-01

A new process has been experimentally and theoretically established for the recovery of manganese from manganese oxide ores, mainly including the reductive leaching of manganese by ethylenediaminetetraacetic acid (EDTA), EDTA recovery, and manganese electrolysis. The experimental conditions for this process were investigated. Moderate leaching environment by EDTA with the pH in the range of 5-6 is of benefit to leach manganese from some manganese oxide ores with high-content impurities, such as iron and aluminum. Most of EDTA can be recovered by acidification. A small amount of the residual EDTA in the electrolyte can prevent the generation of anode mud. In addition, trimanganese tetroxide (Mn3O4) can be obtained by the roasting of the EDTA-Mn crystallized product.

Raman spectroscopy of efflorescent sulfate salts from Iron Mountain Mine Superfund Site, California

Science.gov (United States)

Sobron, Pablo; Alpers, Charles N.

2013-01-01

The Iron Mountain Mine Superfund Site near Redding, California, is a massive sulfide ore deposit that was mined for iron, silver, gold, copper, zinc, and pyrite intermittently for nearly 100 years. As a result, both water and air reached the sulfide deposits deep within the mountain, producing acid mine drainage consisting of sulfuric acid and heavy metals from the ore. Particularly, the drainage water from the Richmond Mine at Iron Mountain is among the most acidic waters naturally found on Earth. The mineralogy at Iron Mountain can serve as a proxy for understanding sulfate formation on Mars. Selected sulfate efflorescent salts from Iron Mountain, formed from extremely acidic waters via drainage from sulfide mining, have been characterized by means of Raman spectroscopy. Gypsum, ferricopiapite, copiapite, melanterite, coquimbite, and voltaite are found within the samples. This work has implications for Mars mineralogical and geochemical investigations as well as for terrestrial environmental investigations related to acid mine drainage contamination.

Raman spectroscopy of efflorescent sulfate salts from Iron Mountain Mine Superfund Site, California.

Science.gov (United States)

Sobron, Pablo; Alpers, Charles N

2013-03-01

The Iron Mountain Mine Superfund Site near Redding, California, is a massive sulfide ore deposit that was mined for iron, silver, gold, copper, zinc, and pyrite intermittently for nearly 100 years. As a result, both water and air reached the sulfide deposits deep within the mountain, producing acid mine drainage consisting of sulfuric acid and heavy metals from the ore. Particularly, the drainage water from the Richmond Mine at Iron Mountain is among the most acidic waters naturally found on Earth. The mineralogy at Iron Mountain can serve as a proxy for understanding sulfate formation on Mars. Selected sulfate efflorescent salts from Iron Mountain, formed from extremely acidic waters via drainage from sulfide mining, have been characterized by means of Raman spectroscopy. Gypsum, ferricopiapite, copiapite, melanterite, coquimbite, and voltaite are found within the samples. This work has implications for Mars mineralogical and geochemical investigations as well as for terrestrial environmental investigations related to acid mine drainage contamination.

Discovery of a Novel Cationic Surfactant: Tributyltetradecyl-Phosphonium Chloride for Iron Ore Flotation: From Prediction to Experimental Verification

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Pan Chen

2017-12-01

Full Text Available In this work, tributyltetradecyl-phosphonium chloride (TTPC, has been first introduced to be a novel and efficient cationic surfactant for cationic reverse flotation separation of quartz from magnetite. The first-principles density functional theory calculations, Zeta potential measurements and adsorption isotherm measurements consistently predict that TTPC may be a promising collector that is better than dodecyl triethyl ammonium chloride (DTAC, based on the facts that TTPC and DTAC both prefer to physically adsorb on the quartz surface owing to electrostatic force, but the active part (P+(C4H93 of TTPC takes much more positive charges than that (N+(CH33 of DTAC. The micro-flotation and Bench-scale flotation results further verify that TTPC presents a stronger collecting power and much better selectivity for iron ore reverse flotation in comparison to the conventional collector DTAC. Furthermore, the corresponding adsorption mechanism of TTPC on the quartz have also been investigated in detail. This work might show a good example to discover a potential candidate collector by analogy with a known excellent collector based on reasonable prediction.

Sintered Fe-Ni-Cu-Sn-C Alloys Made of Ball-Milled Powders

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Romański A.

2014-10-01

Full Text Available The main objective of this paper was to perform sinterability studies of ball-milled Fe-12%Ni-6.4%Cu-1.6%Sn-0.6%C powders. A mixture of precisely weighed amounts of elemental iron, nickel and graphite, and pre-alloyed 80/20 bronze powders was ball-milled for 8, 30 and 120 hours. After cold-pressing at 400 MPa the specimens were sintered at 900oC for 30 minutes in a reducing atmosphere and subsequently tested for density and hardness as well as subjected to structural studies using scanning electron microscopy (SEM and X-ray diffraction (XRD analysis.

Influence of sintering atmospheres on the aluminium sintering characteristics

International Nuclear Information System (INIS)

Mintzer, S.; Bermudez Belkys, S.

1993-01-01

This paper describes the aluminium powder (Al) cool compacted (at 95% from theoretical density) which was sintered at 903 K during 4 hours at different atmospheres; oxidizing (air), inert Argon (Ar), Nitrogen (N) and high vacuum. The results obtained show: a) porosity measurements; greater porosity when sintering in Ar and air. b) Metallographic and Scanning observations: many fine pores (< 1 μm) and pore lines distributed at random, at air sintering and greater pores distributed preferentially near the surface, in Ar and N atmospheres. c) Dimensional changes: tendency to contraction of the samples at N and vacuum sintering and expansion in Ar or air. d) Mechanical properties: greater strength and fluence stresses at air and N sintering. The analysis of the results is performed considering sintering modes in presence of an oxide layer and dropped inert gases. (Author)

New route for uranium concentrate production from Caetite ore, Bahia State, Brazil; dynamic leaching - direct precipitation

Energy Technology Data Exchange (ETDEWEB)

Morais, Carlos A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: cmorais@cdtn.br; Gomiero, Luiz A.; Scassiotti Filho, Walter [Industrias Nucleares do Brasil S.A. (INB), Caetite, BA (Brazil)]. E-mails: gomiero@inb.gov.br; scassiotti@inb.gov.br

2007-07-01

The common uranium concentrate production consists of ore leaching, uranium purification/concentration by solvent extraction and uranium precipitation as ammonium diuranate steps. In the present work, a new route of uranium concentrate production from Caetite, BA-Brazil ore was investigated. The following steps were investigated: dynamic leaching of the ground ore with sulfuric acid; sulfuric liquor pre-neutralization until pH 3.7; uranium peroxide precipitation. The study was carried out in bath and continuous circuits. In the dynamic leaching of ground ore in agitated tanks the uranium content in the leached ore may be as low as 100 {mu}g/g U{sub 3}O{sub 8}, depending on grinding size. In the pre-neutralization step, the iron content in the liquor is decreased in 99 wt.%, dropping from 3.62 g/L to 0.030 g/L. The sulfate content in the liquor reduces from 46 g/L to 22 g/L. A calcinated final product assaying 99.7 wt.% U{sub 3}O{sub 8} was obtained. The full process recovery was over 94%. (author)

Natural Ores as Oxygen Carriers in Chemical Looping Combustion

Energy Technology Data Exchange (ETDEWEB)

Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

2013-08-01

Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

Boric oxide or boric acid sintering aid for sintering ceramics

International Nuclear Information System (INIS)

Lawler, H.A.

1979-01-01

The invention described relates to the use of liquid sintering aid in processes involving sintering of ceramic materials to produce dense, hard articles having industrial uses. Although the invention is specifically discussed in regard to compositions containing silicon carbide as the ceramic material, other sinterable carbides, for example, titanium carbide, may be utilized as the ceramic material. A liquid sintering aid for densifying ceramic material is selected from solutions of H 3 BO 3 , B 2 O 3 and mixtures of these solutions. In sintering ceramic articles, e.g. silicon carbide, a shaped green body is formed from a particulate ceramic material and a resin binder, and the green body is baked at a temperature of 500 to 1000 0 C to form a porous body. The liquid sintering aid of B 2 O 3 and/or H 3 BO 3 is then dispersed through the porous body and the treated body is sintered at a temperature of 1900 to 2200 0 C to produce the sintered ceramic article. (U.K.)

Advances and Opportunities in Ore Mineralogy

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Nigel J. Cook

2017-11-01

Full Text Available The study of ore minerals is rapidly transforming due to an explosion of new micro- and nano-analytical technologies. These advanced microbeam techniques can expose the physical and chemical character of ore minerals at ever-better spatial resolution and analytical precision. The insights that can be obtained from ten of today’s most important, or emerging, techniques and methodologies are reviewed: laser-ablation inductively-coupled plasma mass spectrometry; focussed ion beam-scanning electron microscopy; high-angle annular dark field scanning transmission electron microscopy; electron back-scatter diffraction; synchrotron X-ray fluorescence mapping; automated mineral analysis (Quantitative Evaluation of Mineralogy via Scanning Electron Microscopy and Mineral Liberation Analysis; nanoscale secondary ion mass spectrometry; atom probe tomography; radioisotope geochronology using ore minerals; and, non-traditional stable isotopes. Many of these technical advances cut across conceptual boundaries between mineralogy and geochemistry and require an in-depth knowledge of the material that is being analysed. These technological advances are accompanied by changing approaches to ore mineralogy: the increased focus on trace element distributions; the challenges offered by nanoscale characterisation; and the recognition of the critical petrogenetic information in gangue minerals, and, thus the need to for a holistic approach to the characterization of mineral assemblages. Using original examples, with an emphasis on iron oxide-copper-gold deposits, we show how increased analytical capabilities, particularly imaging and chemical mapping at the nanoscale, offer the potential to resolve outstanding questions in ore mineralogy. Broad regional or deposit-scale genetic models can be validated or refuted by careful analysis at the smallest scales of observation. As the volume of information at different scales of observation expands, the level of complexity

Fe extraction from çayeli copper ores by bioleaching with eco freiendly acidithiobacillus ferrooxidans

International Nuclear Information System (INIS)

Kocadagistan, M.E.; Bayhan, Y.K.

2017-01-01

Recently, biological treatment; an important recovery process, has became important from the environmental and economical respects in recovery of metallic values from low-grade sulfur-bearing ores or concentrates. Bacterial ore leaching can be applied to extract heavy metals from low grade ores, industrial wastes and other materials on an industrial scale by different procedures. The main objective of this work was to investigate the dissolution of Fe from Çayeli copper ores, via a bioleaching process using Acidithiobacillus ferrooxidans. Experiments performed with batch operation in jar test equipment were conducted at different pH values, pulp densities, inoculum volumes, particle sizes, stirring conditions and operation times. The optimal parameters were found as follows; at pH 2, the pulp density; 4% (w/v), inoculum volume; 4% (v/v), stirring rate; 120 rpm and particle size; -0.053 mm for 192nd and 288th hours, at pH 2, the pulp density; 4% (w/v), inoculum volume; 5% (v/v), stirring speed; 200 rpm and particle size; -0.053 mm for 384th and 480th hours. By performing the bioleaching process under these conditions, almost 99% of the iron extent in the ore was transfer from ore into solution, however the experiments in which distilled water was used instead of modified 9K*, only 18.5% Fe efficiency was obtained. (author)

Bioprocessing of ores: Application to space resources

Science.gov (United States)

Johansson, Karl R.

1992-01-01

The role of microorganisms in the oxidation and leaching of various ores (especially those of copper, iron, and uranium) is well known. This role is increasingly being applied by the mining, metallurgy, and sewage industries in the bioconcentration of metal ions from natural receiving waters and from waste waters. It is concluded that bioprocessing using bacteria in closed reactors may be a variable option for the recovery of metals from the lunar regolith. Obviously, considerable research must be done to define the process, specify the appropriate bacteria, determine the necessary conditions and limitations, and evaluate the overall feasibility.

Distribution of the ore elements in ore bodies of the Zapolyarnoe field (Kola Peninsula

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D. V. Taymasov

2017-12-01

Full Text Available The author conducted studies of the chemical zonality of ore deposits of all types for the sulfide-copper-nickel deposit Zapolyarnoe. Within the deposit of sulfide-copper-nickel ores Zapolyarnoe are the following industrial types of ores: rich interspersed ores, which are interspersed mineralization in peridotites; brecciated ores formed by detrital material; poor interspersed ores characterized by vein-interspersed mineralization; solid ores in a form of massive sulphide emissions. This work is based on operational and detailed exploration data. The author sorted samples according to the types of ores. Using the results, the author derived regression lines and their formulas to rectilinear dependencies. Analysis of the graphs showed that for all types of ores the dependences of copper and cobalt content on nickel content are direct, but at that, in thick-interspersed and brecciated types they are similar, and in scattered-interspersed they differ significantly. It becomes clear that correlation of copper and nickel in ore body depends on the scattered-interspersed ores, whereas the correlation of cobalt and nickel is determined mainly by thick-interspersed and brecciated ores. Dependencies between nickel, copper and cobalt in ores change when concentration of nickel in the ore changes. The graphs also show that the ratio of Ni/Cu in breccias and scattered-interspersed ores, as well as in near-ore metaperidotites, is almost constant at different nickel concentrations, on average 2:1.5 and 1, respectively. Thick- interspersed ores show the tendency towards an increase in the ratio with an increase in nickel content. The Ni/Co ratio increases with an increase of Ni concentration in all types of ores. In rich ores, growth occurs along a stepped curve, and in breccias – rectilinearly. Thus, the analysis of distribution of ore elements in ore bodies indicates a complex heterogeneous composition of sulphide mineralizations in different types of ores

Nickel and Copper-Free Sintered Structural Steels Containing Mn, Cr, Si, and Mo Developed for High Performance Applications

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Cias A.

2017-03-01

Full Text Available In an attempt to study the sinterability of potential high-strength nickel-free sintered structural steels containing Mn, Cr, Si and Mo compacts were prepared based on sponge and water atomised iron powders and on Astaloy prealloyed powders. To these were admixed ferromanganese, ferroslicon, and graphite. The samples were sintered at temperatures 1120 and 1250°C in laboratory tube furnaces in hydrogen, hydrogen-nitrogen atmospheres with dew points better than -60°C or in nitrogen in a semiclosed container in a local microatmosphere. After sintering the samples were slowly cooled or sinterhardened. Generally resultant microstructures were inhomogeneous, consisted of pearlite/ bainite/martensite, but were characterised by an absence of oxide networks. Sintering studies performed over a range of compositions have shown that superior strength, ranging beyond 900 MPa, along with reasonable tensile elongation, can be achieved with these new steels.

Iron-borosilicate soft magnetic composites: The correlation between processing parameters and magnetic properties for high frequency applications

Energy Technology Data Exchange (ETDEWEB)

Gheiratmand, T., E-mail: t.gheiratmand@yahoo.com; Madaah Hosseini, H.R., E-mail: Madaah@sharif.edu; Seyed Reihani, S.M.

2017-05-01

Iron-borosilicate soft magnetic composites are suitable magnetic materials for high temperature and high frequency applications. In this research two different techniques have been applied to fabricate these composites: uniaxial pressing following by sintering and spark plasma sintering. Different processing parameters including the content of borosilicate, the amount of compaction pressure and the size of iron particles have been evaluated through the study of microstructure and magnetic properties. The microstructural observations showed that the borosilicate is distributed on the iron grain boundaries enhancing the resistivity and causing the loss of eddy currents. Increasing the compaction pressure was led to the decrease of electrical resistivity. By increasing the frequency both real and imaginary parts of permeability decreased. The use of higher content of borosilicate resulted in the lower decreasing slop of permeability. Best combination of density, permeability and electrical resistivity was obtained in the sample with 2 wt% of borosilicate. In addition, the densification of powders with fine particles was more difficult than coarse particles due to the inter particles friction and bridging effects. Furthermore, as the particles size increases the size of open porosities before sintering where the borosilicate could aggregate enhances. This could yields to the increase in the electrical resistivity. The high ratio of surface to the volume in the powders with fine particles results in the developing the demagnetizing fields and subsequently, decreasing the permeability. The highest relative density (99.99% of theoretical density) with best distribution of borosilicate was achieved in the composites produced by spark plasma sintering (SPS). The relaxation frequency, obtained from imaginary part of permeability, was found as 340 Hz in the composites made by SPS. - Highlights: • Iron-borosilicate SMC was produced for high temperature and frequency

Nuclear energy - Uranium dioxide powder and sintered pellets - Determination of oxygen/uranium atomic ratio by the amperometric method. 2. ed.

International Nuclear Information System (INIS)

2007-01-01

This International Standard specifies an analytical method for the determination of the oxygen/uranium atomic ratio in uranium dioxide powder and sintered pellets. The method is applicable to reactor grade samples of hyper-stoichiometric uranium dioxide powder and pellets. The presence of reducing agents or residual organic additives invalidates the procedure. The test sample is dissolved in orthophosphoric acid, which does not oxidize the uranium(IV) from UO 2 molecules. Thus, the uranium(VI) that is present in the dissolved solution is from UO 3 and/or U 3 O 8 molecules only, and is proportional to the excess oxygen in these molecules. The uranium(VI) content of the solution is determined by titration with a previously standardized solution of ammonium iron(II) sulfate hexahydrate in orthophosphoric acid. The end-point of the titration is determined amperometrically using a pair of polarized platinum electrodes. The oxygen/uranium ratio is calculated from the uranium(VI) content. A portion, weighing about 1 g, of the test sample is dissolved in orthophosphoric acid. The dissolution is performed in an atmosphere of nitrogen or carbon dioxide when sintered material is being analysed. When highly sintered material is being analysed, the dissolution is performed at a higher temperature in purified phosphoric acid from which the water has been partly removed. The cooled solution is titrated with an orthophosphoric acid solution of ammonium iron(II) sulfate, which has previously been standardized against potassium dichromate. The end-point of the titration is detected by the sudden increase of current between a pair of polarized platinum electrodes on the addition of an excess of ammonium iron(II) sulfate solution. The paper provides information about scope, principle, reactions, reagents, apparatus, preparation of test sample, procedure (uranium dioxide powder, sintered pellets of uranium dioxide, highly sintered pellets of uranium dioxide and determination

Uranium ores

International Nuclear Information System (INIS)

Poty, B.; Roux, J.

1998-01-01

The processing of uranium ores for uranium extraction and concentration is not much different than the processing of other metallic ores. However, thanks to its radioactive property, the prospecting of uranium ores can be performed using geophysical methods. Surface and sub-surface detection methods are a combination of radioactive measurement methods (radium, radon etc..) and classical mining and petroleum prospecting methods. Worldwide uranium prospecting has been more or less active during the last 50 years, but the rise of raw material and energy prices between 1970 and 1980 has incited several countries to develop their nuclear industry in order to diversify their resources and improve their energy independence. The result is a considerable increase of nuclear fuels demand between 1980 and 1990. This paper describes successively: the uranium prospecting methods (direct, indirect and methodology), the uranium deposits (economical definition, uranium ores, and deposits), the exploitation of uranium ores (use of radioactivity, radioprotection, effluents), the worldwide uranium resources (definition of the different categories and present day state of worldwide resources). (J.S.)

Magnetic concentration of iron-titanium ore with vanadium concentrate from campo Alegre de Lourdes - Bahia, Brazil

International Nuclear Information System (INIS)

Delgado, O.; Silva, F.T. da; Ogasawara, T.; Soares, G.F.

1988-01-01

The feasibility studies of magnetic concentration of the Campo Alegre de Lourdes ore were carried out, trying to obtain a maximum recovery of vanadium. As a consequence of the complex nature of the ore, mainly due to the presence of ilmenite as a exolutions in the interior of hematite/martite particles, it was not possible to separate the hematite-ilmenite eficiently, wich would be necessary for obtaining a high grade vanadium concentrate with low titanium content. (author) [pt

Some aspects of barreling in sintered plain carbon steel powder metallurgy preforms during cold upsetting

Directory of Open Access Journals (Sweden)

Sumesh Narayan

2012-04-01

Full Text Available The present research establishes a relationship of bulged diameter with densification and hydrostatic stress in forming of sintered iron (Fe powder metallurgy preforms cold upset under two different frictional conditions, namely, nil/no and graphite lubricant condition. Sintered plain carbon steel cylindrical preforms with carbon (C contents of 0, 0.35, 0.75 and 1.1% with constant initial theoretical density of 84% and aspect ratio of 0.4 and 0.6 were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 minutes at 1200 °C. Each sintered preform was cold upset under two different frictional constraints. It is seen that the degree of bulging reduces with reducing frictional constraints at the die contact surface. Further, it is found that the bulging ratio changed as a function of relative density and hydrostatic stress, respectively, according to the power law equations.

The Promotion of Liquid Phase Sintering of Boron-Containing Powder Metallurgy Steels by Adding Nickel

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Wu Ming-Wei

2015-01-01

Full Text Available Boron is a feasible alloying element for liquid phase sintering (LPS of powder metallurgy (PM steels. This study investigated the effect of nickel (Ni, which is widely used in PM steels, on the liquid phase sintering of boron-containing PM steels. The results showed that the addition of 1.8wt% Ni does not apparently modify the LPS mechanism of boron-containing PM steels. However, adding 1.8wt% Ni slightly improves the LPS densification from 0.60 g/cm3 to 0.65 g/cm3, though the green density is reduced. Thermodynamic simulation demonstrated that the presence of Ni lowers the temperature region of liquid formation, resulting in enhanced LPS densification. Moreover, original graphite powders remains in the steels sintered at 1200 ºC. These graphite powders mostly dissolve into the base iron powder when the sintering temperature is increased from 1200 ºC to 1250 ºC.

Final feasibility study of possibilities and potentials of the disused iron ore mine Konrad (FRG) for low-level waste and decommissioning waste disposal

International Nuclear Information System (INIS)

Brewitz, W.; Stippler, R.

1982-01-01

The ''Institut fur Tieflagerung'' of the Gesellschaft fur Strahlen- and Umweltforschung, in collaboration with the Kernforschungszentrum Karlsruhe, carries out geoscientific and technical investigations in the disused iron ore mine Konrad. The aim is to prove the mine's feasibility for the disposal of low-level radioactive waste and decommissioning waste as well as the use of the existing mining installations. The investigations were initiated in 1975 and are being financed by the Minister for Research and Technology of the Federal Republic of Germany. Since 1978 the work is being supported as well by the Commission of the European Community in the scope of two years each. So far an amount of 60 mio DM has been spent, 86% for maintenance and further operation of the mine and 14% for research work

Research of physical and mechanical properties of electric steel, providing for the grate bars of the roasting and sintering machines improved operational stability

Directory of Open Access Journals (Sweden)

Олександр Давидович Учитель

2016-07-01

Full Text Available The grate bars of the conveyor roasting and sintering machines work in severe, aggressive dust and gaseous medium, under cyclic modes «heating-cooling», as well as under the load of iron ore agglomerates what results in bending stress in the body of the grate bar. Consequently, electric steel grate bar must be resistant to chemical and erosion processes, high cyclically changing temperature and have high mechanical properties. The paper discusses the conditions of the grate bars of conveyor roasting and sintering machines wear, depending on the adopted loading schemes. The materials to be processed can be loaded directly from the hopper (direct download or through the use of a feeder (drum-type feeder, roller, etc.. A simplified method to predict the grate bars surface wear on the strength of a number of assumptions has been developed: normal reaction of the pallet surface to the impact of the batch is assumed constant, equal to the maximum of its value when the pallet is in horizontal position; a layer of the batch moves as a rigid body; surface batch layer sliding velocity as related to the pallet surface is taken medium during the relative motion of the layer and equal to the linear velocity of the pallets; the side faces of the grate bars wear is related to related to the surface wear by linear dependence. The dependence of the wear on the friction forces and the steel wear resistance coefficient has been found out

Contribution to the study of the sintering of ex-carbonyl iron in the {alpha} and {gamma} phases using the micro-fractographic technique; Contribution a l'etude du frittage du fer ex-carbonyle en phases {alpha} et {gamma} par examen des surfaces de rupture au microscope electronique

Energy Technology Data Exchange (ETDEWEB)

Oxley Gaborit de Montjou, M.Th. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-07-01

The micro-fractographic study of the sintering of ex-carbonyl iron has shown or confirmed a number of phenomena of which the principal are as followed: Sintering in the a phase: -) existence of two stages of sintering differentiated by the type of rupture (inter or trans-crystalline); -) marked influence of the content of oxygen in the atmosphere and in the initial compressed sample on the speed of sintering; -) formation of striations on the grain-boundary surfaces and on the inner surface of pores caused by the presence of oxygen. Sintering in the {gamma} phase: -) a pronounced decrease in the speed of sintering: the grains in the initial powder remain in the granular state within the final {alpha} crystal in the iron sintered in the lower {gamma} range even after several hours of sintering; -) this granular structure can be eliminated by intermediate compression thus enabling the sintering process to proceed. A considerable decrease in the speed of sintering if the A{sub 3} point is passed one or more times in the {alpha} range sintering. A high speed sintering if the treatment in the {gamma} range is carried out at or above 1300 C. The results of this study agree with micrographic investigation as well as with dilatometric measurements and known auto-diffusion coefficients. (author) [French] L'etude microfractographique du frittage du fer ex-carbonyle a permis de mettre en evidence ou verifier plusieurs phenomenes dont les principaux sont les suivants: Pour le frittoge en phase {alpha}: -) existence de deux stades de frittage differencies par le type de rupture (inter et transcristalline); -) importance de la teneur en oxygene dans l'atmosphere et dans le comprime initial sur la vitesse de frittage; -) formation de stries dues a la presence d'oxygene sur les plans de joints et a l'interieur des pores. Pour le frittage en phase {gamma}: -) un ralentissement tres prononce de la cinetique du frittage: les granules de la poudre initiale demeurent a l'etat de

Uranium ore processing

International Nuclear Information System (INIS)

Ritcey, G.M.; Haque, K.E.; Lucas, B.H.; Skeaff, J.M.

1983-01-01

The authors have developed a complete method of recovering separately uranium, thorium and radium from impure solids such as ores, concentrates, calcines or tailings containing these metals. The technique involves leaching, in at least one stage. The impure solids in finely divided form with an aqueous leachant containing HCl and/or Cl 2 until acceptable amounts of uranium, thorium and radium are dissolved. Uranium is recovered from the solution by solvent extraction and precipitation. Thorium may also be recovered in the same manner. Radium may be recovered by at least one ion exchange, absorption and precipitation. This amount of iron in the solution must be controlled before the acid solution may be recycled for the leaching process. The calcine leached in the first step is prepared in a two stage roast in the presence of both Cl 2 and a metal sulfide. The first stage is at 350-450 0 and the second at 550-700 0

Environmental natural radioactive and radiation hazard in sedimentary rocks for manganese-iron ore at Um Bogma Area, Sinai, Egypt

International Nuclear Information System (INIS)

Abu-Zeid, H.M; Nada, A; Abd-Elmaksoud, T.M; Ragab, F.M.; El-Assy, I

2011-01-01

The aim of this study was to measure concentrations and distributions of natural radionuclides occurring in sedimentary rocks. The activity concentrations of the naturally occurring radionuclides 238 U, 232 Th,and 40 K in the manganese-iron ore of Um Bogma area which subdivided into three localities Wadi Nasieb (NS), Abu Thor (AT) and Um Bogma (UB) were measured using a high-purity germanium detector.The average concentration values of 238 U, 232 Th, and 40 K in the surveyed samples in Wadi Nasieb are 261.38, 9.57 and 130.63 Bqkg -1 respectively also in Abu Thor 224.51,6.7,94.99 Bqkg -1 and in Um Bogma 441.47,7.87 and 272.69 Bqkg -1 . The overall outdoor terrestrial gamma dose rates fluctuate from 103.38 to 193.5 nGyh -1 for all localities. The annual effective dose rate for all localities ranged from 0.13 to 0.24 mSvy -1 have been compared with the global averages which are within the safety range for workers in the studied localities.

Effect of microstructure changes on magnetic properties of spark plasma sintered Nd-Fe-B powders

Directory of Open Access Journals (Sweden)

Michalski B.

2013-01-01

Full Text Available In this study the SPS method was applied for low RE content (8,5% at. and high RE content (13,5 % at. MQ powders. The powders were sintered in a wide range of temperature, for 5 min., under pressure of 35 MPa. The low RE content grade, densified reluctantly and gained the density close to the theoretical value only for 850 °C. The coercivity decreased gradually with increasing sintering temperature. On the other hand, the densification of the higher RE content grade powder occurred much easier and the coercivity, close to the theoretical value, was achieved already at 650 °C. The coercivity of this material also decreased with increasing sintering temperature. Microstructural studies revealed that the SPS sintering process leads to partial decomposition of the Nd2Fe14B phase. The proportion of the RE-rich and iron phases increases parallel to the increasing sintering temperature. On the basis of the current results one can conclude that fabrication of high density MQ powders based magnets by the SPS method is possible, however the powders having higher RE content should be used for this purpose and the sintering temperature as low as possible, related to density, should be kept.

Effects of sintering temperature on the mechanical properties of sintered NdFeB permanent magnets prepared by spark plasma sintering

International Nuclear Information System (INIS)

Wang, G.P.; Liu, W.Q.; Huang, Y.L.; Ma, S.C.; Zhong, Z.C.

2014-01-01

Sintered NdFeB-based permanent magnets were fabricated by spark plasma sintering (SPS) and a conventional method to investigate the mechanical and magnetic properties. The experimental results showed that sintered NdFeB magnet prepared by the spark plasma sintering (SPS NdFeB) possesses a better mechanical properties compared to the conventionally sintered one, of which the maximum value of bending strength and Vickers hardness was 402.3 MPa and 778.1 MPa, respectively. The effects of sintering temperature on bending strength and Vickers hardness were investigated. It was shown that the bending strength firstly increases to the maximum value and then decreases with the increase of sintering temperature in a certain range. The investigations of microstructures and mechanical properties indicated that the unique sintering mechanism in the SPS process is responsible for the improvement of mechanical properties of SPS NdFeB. Furthermore, the relations between the mechanical properties and relevant microstructure have been analyzed based on the experimental fact. - Highlights: • Studied the sintering temperature effect on strengthening mechanism of NdFeB magnet firstly. • It showed that sintering temperature may effectively affect the mechanical properties. • The maximum bending strength and Vickers hardness was 402.3 MPa and 778.1 MPa, respectively

Effects of sintering temperature on the mechanical properties of sintered NdFeB permanent magnets prepared by spark plasma sintering

Energy Technology Data Exchange (ETDEWEB)

Wang, G.P., E-mail: wgp@jxnu.edu.cn [College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022 (China); Liu, W.Q. [Key Laboratory of Advanced Functional Materials Science and Engineering, Ministry of Education, Beijing University of Technology, Beijing 100022 (China); Huang, Y.L.; Ma, S.C.; Zhong, Z.C. [School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063 (China)

2014-01-15

Sintered NdFeB-based permanent magnets were fabricated by spark plasma sintering (SPS) and a conventional method to investigate the mechanical and magnetic properties. The experimental results showed that sintered NdFeB magnet prepared by the spark plasma sintering (SPS NdFeB) possesses a better mechanical properties compared to the conventionally sintered one, of which the maximum value of bending strength and Vickers hardness was 402.3 MPa and 778.1 MPa, respectively. The effects of sintering temperature on bending strength and Vickers hardness were investigated. It was shown that the bending strength firstly increases to the maximum value and then decreases with the increase of sintering temperature in a certain range. The investigations of microstructures and mechanical properties indicated that the unique sintering mechanism in the SPS process is responsible for the improvement of mechanical properties of SPS NdFeB. Furthermore, the relations between the mechanical properties and relevant microstructure have been analyzed based on the experimental fact. - Highlights: • Studied the sintering temperature effect on strengthening mechanism of NdFeB magnet firstly. • It showed that sintering temperature may effectively affect the mechanical properties. • The maximum bending strength and Vickers hardness was 402.3 MPa and 778.1 MPa, respectively.

Geological structure and prospects of noble metal ore mineralization of the Khayrkhan gabbroid massif (Western Mongolia)

Science.gov (United States)

Kurumshieva, K. R.; Gertner, I. F.; Tishin, P. A.

2017-12-01

An analysis of the distribution of noble metals in zones of sulfide mineralization makes it possible to justify the isolation of four ore-bearing horizons with a specific geochemical zonation. A rise in the gold content relative to palladium and platinum is observed from the bottom upwards along the section of the stratified series of gabbroids. The study of the mineral phases of sulphides and the noble minerals itself indicates the evolution of hydrothermal solutions, which determines the different activity and mobility of the fluid (mercury, tellurium, sulfur) and ore (copper, nickel, iron, platinum, gold and silver) components.

Study on the determination of ore-formation age of primary gold ore

International Nuclear Information System (INIS)

Ying Junlong; Zhao Puyun; Guo Hong

1997-01-01

The accurate determination of gold ore-formation age and ore-source isotope composition are of important significance in the research on gold geology and prospecting. According to the summary of three year indoor and field work, the ore-formation ages and isotope compositions of some typical gold deposits were obtained: The age of gold ore of the Wuhuaaobao deposit in geo-syncline region north to the north margin of North-China paleo-land is 130-120 Ma corresponding to the Late-orogenic stage. The ore-formation age of the Saiwusu gold deposit in the southern platform region is 211 +- 15 Ma, recycling reworking of the old-land. The Hougou-Huangtuliang gold deposit located in the middle of the platform region is 243 +- 7 Ma old attributed to the regeneration ore-formation on the old-land. the age of Jiaojia-Rushan gold deposit in Eastern Shandong is 122.7 +- 3.4 Ma and 128 +- 23 Ma belonging to Yanshanian stage. The Babaoshan gold-silver deposit in Cathaysian old-land is 140 +- 5 Ma old originated from volcanic hydrothermal ore-formation

Structural and magnetic properties of yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrites prepared by microemulsion method

Energy Technology Data Exchange (ETDEWEB)

Akhtar, Majid Niaz, E-mail: majidniazakhtar@ciitlahore.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bakar Sulong, Abu [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Khan, Muhammad Azhar [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Ahmad, Mukhtar [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Murtaza, Ghulam [Centre for Advanced Studies in Physics, G.C. University, Lahore, Pakistan" f Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal Pakistan (Pakistan); Raza, M.R. [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal (Pakistan); Raza, R.; Saleem, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Kashif, M. [Department of Physics, Govt. College University Faisalabad (Pakistan)

2016-03-01

Yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrite samples were synthesized by microemulsion method. The effect of sintering was examined by heating the samples at 900, 1000, and 1100 °C. The YIG and YAIG samples were then characterized using X-ray diffraction and field-emission scanning electron microscopy. Static and dynamic magnetic properties were measured by evaluating initial permeability, Q factor, and vibrating sample magnetometry properties of YIG and YAIG samples. YIG samples sintered at 1100 °C showed higher initial permeability and Q factor compared with YAIG samples. However, hysteresis loops also showed variations in the saturation magnetization, remanence, and coercivity of YIG and YAIG samples sintered at 900, 1000, and 1100 °C. The observed magnetic parameter such as saturation magnetization, coercivity and initial permeability are strongly affected by increasing temperature. The saturation magnetization and coercivity of YIG and YAIG nanoferrites were found in the range 11.56–19.92 emu/g and 7.30–87.70 Oe respectively. Furthermore, the decreasing trends in the static and magnetic properties of YAIG samples may be due to the introduction of Al ions in the YIG crystal lattice. Thus, YIG and YAIG sintered at 1100 °C can be used for wide-ranging frequency applications. - Highlights: • Static and dynamic magnetic properties of YIG and YAIG nanoferrites were determined. • Saturation magnetization, Q and initial permeability increased in YIG nanoferites. • Possible use of these nanoferrites for sensing and switching applications.

An innovative method for nondestructive analysis of cast iron artifacts at Hopewell Furnace National Historic Site, Pennsylvania

Science.gov (United States)

Sloto, R.A.; Helmke, M.F.

2011-01-01

Iron ore containing elevated concentrations of trace metals was smelted at Hopewell Furnace during its 113 years of operation (1771-1883). For this study, we sampled iron ore, cast iron furnace products, slag, soil, groundwater, streamflow, and streambed sediment to determine the fate of trace metals released into the environment during the iron-smelting process. Standard techniques were used to sample and analyze all media except cast iron. We analyzed the trace-metal content of the cast iron using a portable X-ray fluorescence spectrometer, which provided rapid, on-site, nondestructive analyses for 23 elements. The artifacts analyzed included eight cast iron stoves, a footed pot, and a kettle in the Hopewell Furnace museum. We measured elevated concentrations of arsenic, copper, lead, and zinc in the cast iron. Lead concentrations as great as 3,150 parts per million were measured in the stoves. Cobalt was detectable but not quantifiable because of interference with iron. Our study found that arsenic, cobalt, and lead were not released to soil or slag, which could pose a significant health risk to visitors and employees. Instead, our study demonstrates these heavy metals remained with the cast iron and were removed from the site.

Environmental radiation hazards around some iron mines and steel plants of Karnataka state

International Nuclear Information System (INIS)

Sannappa, J.

2013-01-01

The primordial radionuclides ( 226 Ra, 232 Th and 40 K) are present in air, food, water, soils, rocks, mineral ores and building materials, are the sources of natural radiation. The sun, stars, rocks, and even our own body emits natural radiation. We live in a sea of natural radioactivity. Work activities involved in naturally occurring radioactive materials (NORM) are potential sources of radiation exposure to workers and members of publics. Iron, Chromite, Uranium, Phosphate and other ores contains higher activity of radionuclides. The iron ore is widely distributed in Bellary, Chitradurga, Tumkur and Chickmagalore districts of Karnataka state. The mining creates a number of environmental problems, that is destructions of important fauna and flora in this affected areas and also this leads various diseases like asthma, leukemia intestine, kidney and liver damage and lung cancer. The environmental γ-radiation levels were measured in this study area using environmental radiation dosimetry. The activity of radionuclides present in the ore samples were estimated by using Hyper Pure Germanium Detector (HPGe). The radon concentration in groundwater and indoor and outdoor concentration were measured by Emanometry and SSNTD techniques. The higher gamma equivalent effective doses were observed at the industrial operation and where the large quantity of iron ore and fines were dumped at the mining sites. The absorbed gamma dose to the workers in study area is slightly higher than the global average. The present work highlights the influence of mining activity, mineral processing and industrial operations are enhanced the fine sized particles, and radon in indoor and outdoor atmosphere is the sources of external radiation dose to the workers and publics. (author)

Hydrothermal oxidation in the Biwabik Iron Formation, MN, USA

Science.gov (United States)

Losh, Steven; Rague, Ryan

2018-02-01

Precambrian iron formations throughout the world, notably in Australia, Brazil, and South Africa, show evidence of hypogene (≥ 110 °C, mostly > 250 °C) oxidation, alteration, and silica dissolution as a result of tectonic or magmatic activity. Although hydrothermal oxidation has been proposed for the prototype Lake Superior-type iron formation, the Biwabik Iron Formation in Minnesota (USA), it has not been documented there. By examining oxidized and unoxidized Biwabik Iron Formation in three mines, including material from high-angle faults that are associated with oxidation, we document an early hypogene oxidation event ( 175 °C) involving medium-salinity aqueous fluids (8.4 ± 4.9 wt% NaCl equiv) that infiltrated iron formation along high-angle faults. At the Hibbing Taconite Mine, hydrothermal fluids oxidized iron carbonates and silicates near faults, producing goethite ± quartz. In contrast with much of the oxidized iron ores on the Mesabi Range, silica was not removed but rather recrystallized during this event, perhaps lying in a rock-dominated system at low cumulative fluid flux. During the hydrothermal oxidation event in the Hibbing Taconite deposit, quartz-filled microfractures and irregular inclusions commonly formed in coarse variably oxidized magnetite, currently the ore mineral: these inclusions degrade the ore by introducing excess silica in magnetic concentrate. Hydrothermal oxidation at Hibbing Taconite Mine is overprinted by later, relatively minor supergene oxidation both along faults and near the surface, which locally dissolved quartz. At the Fayal Reserve Mine, widespread silicate and carbonate gangue dissolution and iron oxidation was followed by precipitation of pyrite, Mn-siderite, apatite, and other minerals in void spaces, which prevented post-oxidation compaction and significant volume loss in the sampled rocks. Although definitive temperature data for this assemblage are needed, the weight of evidence indicates that this

Iron behaviour in the process of stratum-infiltration uranium ore formation

International Nuclear Information System (INIS)

Shmariovich, E.M.; Golubev, V.S.

1980-01-01

Investigated has been the behaviour of iron in the process of stratum infiltration uranium mineralization. Iron is partially avacuated from the forward part of the stratum oxidation zone during the development of infiltration uranium mineralization in pyritiferous rocks. This phenomenon is characterized quantitatively and described on the basis of equations of physical chemistry and dynamics of geochemical processes. Local regions of epigenetic ferruginization caused by opposite diffusion of iron and its precipitation in oxygenous conditions often occur at the sections of sharp moderation of limonitization zone advance. Formation of similar ferruginous margins takes place in a very short geological period (less than thousand years)

Bacterial leaching of pyritic gold ores

Energy Technology Data Exchange (ETDEWEB)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J. [Monash Univ., Clayton, VIC (Australia). Dept. of Physics; Jay, W.H. [Monash Univ., Clayton, VIC (Australia). Chemical Engineering Department

1996-12-31

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. {sup 57}Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS{sub 2}, and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J.; Jay, W.H.

1996-01-01

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. 57 Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS 2 , and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Energy, metals and ores in France in 1983

International Nuclear Information System (INIS)

Anon.

1984-01-01

Every year the Annales des Mines devote one issue to the activities of the power producing and mineral industries. This issue refers to the year 1983, with a recapitulation of previous years. A first part describes the activity of the following principal sectors. Energy: solid mineral fuel, hydrocarbons, gas, electricity, uranium, geothermal power. Ores and metals: aluminium, antimony, silver, chromium, copper, tin, iron, manganese, nickel, gold, lead, tungsten, zinc. Nonmetallic substances: barite, phosphate, potash, salt, sulphur, fluorspar. The elements concern mainly France but they are presented in a world-wide context. A second part gives statistical items, completed and illustrated by diagrams [fr

Energy, metals and ores in France in 1982

International Nuclear Information System (INIS)

Anon.

1983-01-01

Every year the Annales des Mines devote one issue to the activities of the power producing and mineral industries. This issue refers to the year 1982, with a recapitulation of previous years. A first part describes the activity of the following principal sectors. Energy: solid mineral fuel, hydrocarbons, gas, electricity, uranium, geothermal power. Ores and metals: aluminium, antimony, silver, chromium, copper, tin, iron, manganese, nickel, gold, lead, tungsten, zinc. Nonmetallic substances: barite, phosphate, potash, salt, sulphur, fluorspar. The elements concern mainly France but they are presented in a world-wide context. A second part gives statistical items, completed and illustrated by diagrams [fr

Liquid-liquid extraction of iron (III) from Ouenza iron ore leach liquor ...

African Journals Online (AJOL)

The effect of several parameters, such as contact time, HCl concentration, TBP concentration and chloride inorganic salt (KCl) concentration on the efficiency of extraction of iron was examined at 19±2°C. It was found that, for 2 min 3M TBP in presence of 5M HCl and 2 M KCl solutions led to a high yiel of extraction (98.57 ...

Recovery of metals from low-grade ores by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Kamali, M.; Mulligan, C.N. [Concordia Univ., Dept. of Building, Civil and Environmental Engineering, Montreal, Quebec (Canada)]. E-mail: mulligan@civil.concordia.ca

2002-06-15

The main concern of this study is to develop a feasible and economical technique to microbially recover metals from oxide low-grade ores. Owing to the significant quantities of metals that are embodied in low - grade ores and mining residues, these are considered new sources of metals. On the other hand, they potentially endanger the environment, as the metals they contain may be released to the environment in a hazardous form. Hence, mining industries are seeking an efficient technique to handle these ores. Pyrometallurgical and hydrometallurgical techniques are either very expensive, energy intensive or have a negative impact on the environment. For these reasons, biohydrometallurgical techniques are coming into perspective. In this study, by employing Aspergillus niger, the feasibility of recovery of metals from a mining residue is shown. A. niger exhibits good potential in generating a variety of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulphuric acid was added to the medium. Different agricultural wastes such as potato peels were tested. In addition to this, different auxiliary processes were tried in order to either elevate the efficiency or reduce costs. Finally, maximum solubilization of 68%, 46% and 34% were achieved for copper, zinc and nickel, respectively. Also iron codissolution was minimized as only 7% removal occurred. (author)

Recovery of metals from low-grade ores by Aspergillus niger

International Nuclear Information System (INIS)

Kamali, M.; Mulligan, C.N.

2002-01-01

The main concern of this study is to develop a feasible and economical technique to microbially recover metals from oxide low-grade ores. Owing to the significant quantities of metals that are embodied in low - grade ores and mining residues, these are considered new sources of metals. On the other hand, they potentially endanger the environment, as the metals they contain may be released to the environment in a hazardous form. Hence, mining industries are seeking an efficient technique to handle these ores. Pyrometallurgical and hydrometallurgical techniques are either very expensive, energy intensive or have a negative impact on the environment. For these reasons, biohydrometallurgical techniques are coming into perspective. In this study, by employing Aspergillus niger, the feasibility of recovery of metals from a mining residue is shown. A. niger exhibits good potential in generating a variety of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulphuric acid was added to the medium. Different agricultural wastes such as potato peels were tested. In addition to this, different auxiliary processes were tried in order to either elevate the efficiency or reduce costs. Finally, maximum solubilization of 68%, 46% and 34% were achieved for copper, zinc and nickel, respectively. Also iron codissolution was minimized as only 7% removal occurred. (author)

OCCURRENCE OF LEAD-ZINK ORE AT Mt. IVANŠČICA NEAR IVANEC (CROATIA

Directory of Open Access Journals (Sweden)

Boris Šinkovec

2000-12-01

Full Text Available Mineral and ore occurences at Mt. Ivanščica are situated in the Middle Triassic carbonate rocks and are of epigenetic origin. These occurences are characterised by simple paragenesis of primary sulphides of leads and zinc and traces of sulphides of iron and copper. This mineralization is similar to Mississippi Valley Pb-Zn deposits (the paper is published in Croatian.

Estudio de la granulación de la mezcla de minerales de hierro en el proceso de sinterización. I parte. Granulación

Directory of Open Access Journals (Sweden)

Formoso, Antonio

2000-08-01

Full Text Available The granulation process of the ore mixture is described and the fitness for granulation of several iron ores form part of the mixture is studied. With a good granulation and sintering maximum temperature control is possible to achieve the best sintered structure, forming by a hematite nucleous bonded by acicular ferrites. The industrial experience of several types of granulation is described.

Se describe el proceso de granulación de la mezcla de mineral y se estudia la aptitud a la granulación de una serie de minerales de hierro que forman parte de la mezcla. Con una buena granulación y control de la temperatura máxima de sinterización, se puede conseguir la estructura óptima del sintetizado, formada por un núcleo de hematita rodeado por una red de ferritos aciculares. Se expone la práctica industrial de distintas formas de realizar la granulación.

Effect of additives in reducing ash sintering and slagging in biomass combustion applications

Energy Technology Data Exchange (ETDEWEB)

Wang, Liang

2012-07-01

The objective of this study was to investigate sintering and slagging behaviors of biofuels during combustion processes. Biofuels tested are derived from the agricultural sector, wood and furniture industry as well as from municipal sewage sludge. It was also the aim to test and evaluate additives that can prevent and abate biomass ash sintering by conducting laboratory and industrial scale tests. Sintering characteristics of sewage sludge ashes at elevated temperatures were investigated by means of different laboratory methods. Utilizing of phosphorus participation agents Al2(SO4)3 or Fe2(SO4)3 caused substantially high contents of aluminum or iron in the studied sewage sludge ashes, respectively. High initial melting temperatures over 1100 degrees C and low sintering tendencies were observed from the sewage sludge ashes rich in aluminum. It was related to presence and formation of the inert mineral phases such as aluminum oxide, quartz and calcium aluminum silicates in the aluminum rich sewage sludge ashes at elevated temperatures. A low melting temperature, about 994 degree C, was detected from the iron rich sewage sludge ash. Severe sintering of this sewage sludge ash was mainly due to generation of low temperature melting iron silicates, as results of interaction and re-assemblage of hematite (Fe2O3), quartz (SiO2) and alkali feldspars under heating. Fusion behaviors of corn cob ashes under rising temperatures were characterized. The work revealed that chemical compositions of corn cob ashes are dominated by potassium, silicon, chlorine and phosphorus. However, the relative concentrations of these principal elements are considerably different for three studied corn cob ashes, which have major influence on ash transformation reactions and sintering tendencies. Compared with the other two, the chemical composition of the Waimanalo corn cob (WCob) was characterized with the highest K/Cl, Si/(Ca+Mg) and (Si+P+K)/(Ca+Mg) molar ratios, which was favorable for

Concentration of rare earths ore from Pocos de Caldas - MG, Brazil

International Nuclear Information System (INIS)

Sampaio, J.A.; Lins, F.F.; Porphirio, N.H.

1990-01-01

The objective of this research was to concentrate, mainly by flotation, a rare-earth ore body. The valuable mineral is bastnaesite which occurs intimately associated with iron oxides and other gangue minerals, making difficult to get a concentrate of commercial grade. The use of oleic acid at a pulp temperature of -80 sup(0)C gave a concentrate of 23% rare-earth oxides at 72% overall recovery. The magnetic separation could enhance the grade of the flotation feed. (author)

Reduction Behaviors of Carbon Composite Iron Oxide Briquette Under Oxidation Atmosphere

Energy Technology Data Exchange (ETDEWEB)

Lee, Ki-Woo; Kim, Kang-Min; Kwon, Jae-Hong; Han, Jeong-Whan [Inha University, Incheon (Korea, Republic of); Son, Sang-Han [POSCO, Pohang (Korea, Republic of)

2017-01-15

The carbon composite iron oxide briquette (CCB) is considered a potential solution to the upcoming use of low grade iron resources in the ironmaking process. CCB is able to reduce raw material cost by enabling the use of low grade powdered iron ores and coal. Additionally, the fast reduction of iron oxides by direct contact with coal can be utilized. In this study, the reduction behaviors of CCB were investigated in the temperature range of 200-1200 ℃ under oxidizing atmosphere. Briquettes were prepared by mixing iron ore and coal in a weight ratio of 8:2. Then reduction experiments were carried out in a mixed gas atmosphere of N{sub 2}, O{sub 2}, and CO{sub 2}. Compressive strength tests and quantitative analysis were performed by taking samples at each target temperature. In addition, the reduction degree depending on the reaction time was evaluated by off-gas analysis during the reduction test. It was found that the compressive strength and the metallization degree of the reduced briquettes increased with increases in the reaction temperature and holding time. However, it tended to decrease when the re-oxidation phenomenon was caused by injected oxygen. The degree of reduction reached a maximum value in 26 minutes. Therefore, the re-oxidation phenomenon becomes dominant after 26 minutes.

Acid-base properties and surface complexation modeling of phosphate anion adsorption by wasted low grade iron ore with high phosphorus.

Science.gov (United States)

Yuan, Xiaoli; Bai, Chenguang; Xia, Wentang; An, Juan

2014-08-15

The adsorption phenomena and specific reaction processes of phosphate onto wasted low grade iron ore with high phosphorus (WLGIOWHP) were studied in this work. Zeta potential and Fourier transform infrared spectroscopy (FTIR) analyses were used to elucidate the interaction mechanism between WLGIOWHP and aqueous solution. The results implied that the main adsorption mechanism was the replacement of surface hydroxyl groups by phosphate via the formation of inner-sphere complex. The adsorption process was characterized by chemical adsorption onto WLGIOWHP. The non-electrostatic model (NEM) was used to simulate the surface adsorption of phosphate onto WLGIOWHP. The total surface site density and protonation constants for NEM (N(T)=1.6×10(-4) mol/g, K(a1)=2.2×10(-4), K(a2)=6.82×10(-9)) were obtained by non-linear data fitting of acid-base titrations. In addition, the NEM was used to establish the surface adsorption complexation modeling of phosphate onto WLGIOWHP. The model successfully predicted the adsorption of phosphate onto WLGIOWHP from municipal wastewater. Copyright © 2014 Elsevier Inc. All rights reserved.

Sintering of nonstoichiometric UO2

International Nuclear Information System (INIS)

Susnik, D.; Holc, J.

1983-01-01

Activated sintering of UO 2 pellets at 1100 deg C is described. In CO 2 atmosphere is UO 2 is nonstoichiometric and pellets from active UO 2 powders sinter at 900 deg C to high density. At 1100 deg C the final sintered density is practically achieved at heating on sintering temperature. After reduction and cooling in H 2 atmosphere which is followed sintering in CO 2 the structure is identical to the structured UO 2 pellets sintered at high temperature in H 2 . Density of activated sintered UO 2 pellets is stable, even after additional sintering at 1800 deg C. (author)

Titanium Powder Sintering in a Graphite Furnace and Mechanical Properties of Sintered Parts

Directory of Open Access Journals (Sweden)

Changzhou Yu

2017-02-01

Full Text Available Recent accreditation of titanium powder products for commercial aircraft applications marks a milestone in titanium powder metallurgy. Currently, powder metallurgical titanium production primarily relies on vacuum sintering. This work reported on the feasibility of powder sintering in a non-vacuum furnace and the tensile properties of the as-sintered Ti. Specifically, we investigated atmospheric sintering of commercially pure (C.P. titanium in a graphite furnace backfilled with argon and studied the effects of common contaminants (C, O, N on sintering densification of titanium. It is found that on the surface of the as-sintered titanium, a severely contaminated porous scale was formed and identified as titanium oxycarbonitride. Despite the porous surface, the sintered density in the sample interiors increased with increasing sintering temperature and holding time. Tensile specimens cut from different positions within a large sintered cylinder reveal different tensile properties, strongly dependent on the impurity level mainly carbon and oxygen. Depending on where the specimen is taken from the sintered compact, ultimate tensile strength varied from 300 to 580 MPa. An average tensile elongation of 5% to 7% was observed. Largely depending on the interstitial contents, the fracture modes from typical brittle intergranular fracture to typical ductile fracture.

The development of fabrication techniques for europia/iron cermet tips for coarse-control arms in DIDO and PLUTO

International Nuclear Information System (INIS)

Moore, D.A.; Tarrant, E.A.

1980-11-01

The applicability of cermet-fabrication techniques to the production of europia/iron cermets for use as coarse-control arm tips in the materials test reactors DIDO and PLUTO has been investigated. Spheroids of europia were prepared by a dry agglomeration process. These were sintered, dispersed in iron powder and pressed into plates; the plates were then sintered to densify the iron matrix. These stages were optimised to produce a strong cermet with a europia density of >= 2.75 g/cm 3 . The uniformity of distribution of the absorber particles was confirmed by radiography, and adequate neutron-absorption worth by measurements carried out in the GLEEP reactor. An outline flow sheet has been prepared for the manufacture of europia/iron cermet plates suitable for use in the tips of DIDO and PLUTO coarse-control arms. (author)