Challenges with modifications of the McClean Lake mill to process midwest ore

International Nuclear Information System (INIS)

Nguyen, T.T.; Backham, L.

2010-01-01

Midwest is a unique uranium deposit with exceptionally high arsenic content. The ore body is located 17 km west of the McClean Lake operation. The McClean Lake mill will be modified to process Midwest ore and handle solid wastes from the Midwest water treatment plant. This paper describes the modifications required of the McClean Lake mill, process challenges associated with treatment of the arsenic, and the possibility of recovering nickel and cobalt as a by-product. It also reviews the complexity in the design of the Midwest water treatment facility which incorporates reverse osmosis technology with conventional physical-chemical water treatment. (author)

Radiation monitoring in the mining and milling of radioactive ores

International Nuclear Information System (INIS)

1989-01-01

The present Guide is a revision of IAEA Safety Series No. 43. It explains the recommendations on administrative requirements for the organization of radiation protection in the mining and milling of radioactive ores, and the monitoring requirements, including methods, techniques, instrumentation and strategy. 146 refs, 9 figs, 14 tabs

Decommissioning of facilities for mining and milling or radioactive ores and closeout of residues

International Nuclear Information System (INIS)

1994-01-01

The purpose of this report is to provide information to Member States in order to assist in planning and implementing the decommissioning/closeout of uranium mine/mill facilities, mines, tailings impoundments, mining debris piles, leach residues and unprocessed ore stockpiles. The report presents an overview of the factors involved in planning and implementing the decommissioning/closeout of uranium mine/mill facilities. The information applies to mines, mills, tailings piles, mining debris piles and leach residues that are present as operational, mothballed or abandoned projects, as well as to future mining and milling projects. The report identifies the major factors that need to be considered in the decommissioning/closeout activities, including regulatory considerations; decommissioning of the mine/mill buildings, structures and facilities; decommissioning/closeout of open pit and underground mines; decommissioning/closeout of tailings impoundments; decommissioning/closeout of mining debris piles, unprocessed ore and other contaminated material such as heap leach piles, in situe leach facilities and contaminated soils; restoration of the site, vicinity properties and groundwater; radiation protection and health and safety considerations; and an assessment of costs and post-decommissioning or post-closeout maintenance and monitoring needs. 55 refs, figs and tabs

Mill tailings based composites as paste backfill in mines of U-bearing dolomitic limestone ore

Directory of Open Access Journals (Sweden)

Sandeep Panchal

2018-04-01

Full Text Available This paper elaborates on the development of paste backfill using mill tailings generated during the processing of a uranium ore deposit hosted in dolomitic limestone. The tailings have been characterized in terms of the physical, chemical and mineralogical properties. Time-dependent rheological behaviors and geotechnical properties of cemented paste backfill (CPB are also determined. The studies show that the mill tailing has the potential to form paste and the CPB has adequate strength to provide support to mine pillars, roofs, and walls. Keywords: Mining engineering, Uranium ore deposit, Tailings, Cemented paste backfill (CPB, Rheology, Compressive strength

Recycling of mill scale in sintering process

Directory of Open Access Journals (Sweden)

El-Hussiny N.A.

2011-01-01

Full Text Available This investigation deals with the effect of replacing some amount of Baharia high barite iron ore concentrate by mill scale waste which was characterized by high iron oxide content on the parameters of the sintering process., and investigation the effect of different amount of coke breeze added on sintering process parameters when using 5% mill scale waste with 95% iron ore concentrate. The results of this work show that, replacement of iron ore concentrate with mill scale increases the amount of ready made sinter, sinter strength and productivity of the sinter machine and productivity at blast furnace yard. Also, the increase of coke breeze leads to an increase the ready made sinter and productivity of the sintering machine at blast furnace yard. The productivity of the sintering machine after 5% decreased slightly due to the decrease of vertical velocity.

Origin assessment of uranium ore concentrates based on their rare-earth elemental impurity pattern

Energy Technology Data Exchange (ETDEWEB)

Varga, Z.; Wallenius, M.; Mayer, K. [Commission of the European Communities, Karlsruhe (Germany). European Inst. for Transuranium Elements

2010-07-01

The rare-earth element pattern was used as an additional tool for the identification and origin assessment of uranium ore concentrates (yellow cakes) for nuclear forensic purposes. By this means, the source of an unknown material can be straightforwardly verified by comparing the pattern with that of a known or declared sample. In contrast to other indicators used for nuclear forensic studies, the provenance of the material can also be assessed in several cases even if no comparison sample is available due to the characteristic pattern. The milling process was found not to change the pattern and no significant elemental fractionation occurs between the rare-earth elements, thus the pattern in the yellow cakes corresponds to that found in the uranium ore. (orig.)

Radiation protection of workers in the mining and milling of radioactive ores. Code of practice and technical addendum. 1983 ed

International Nuclear Information System (INIS)

1983-01-01

This Code of Practice sets forth the means of ensuring protection against ionizing radiation for workers engaged in mining and milling of radioactive ores: general provisions outlining the responsibilities of the employer and the worker, limits of radiation exposure, administrative organization of radiation protection, radiation surveillance, engineering and administrative protective measures and medical surveillance. It is designed to facilitate the preparation and adoption of national and local regulations and factory rules for radiation protection in mining and milling of radioactive ores.

Investigation of the degree of equilibrium of the long-lived uranium-238 decay-chain members in airborne and bulk uranium-ore dusts

International Nuclear Information System (INIS)

Jackson, P.O.; Thomas, C.W.

1982-08-01

The degree of disequilibrium among 238 U decay chain members in some airborne dusts and typical ores has been established by precise radiochemical analyses. This information is necessary to evaluate the lung dose model currently used for estimating the effect of the inhalation of uranium ore dust. The particle size distributions of airborne decay chain components in dusts at one uranium mill have been investigated. Statistically significant disequilibria were observed for 230 Th, 226 Ra, and 210 Pb in both airborne dusts and composite ore samples. With the exception of ore from one mill in the United States, most of the daughter concentrations in powdered ore composites were within 10% of 238 U. In airborne dusts, the concentration of 226 Ra was typically below 238 U; the minimum 226 Ra concentration observed for airborne ore dusts was 56% of equilibrium. A statistically significant particle size dependence was observed for 226 Ra/ 238 U ratios in several airborne dusts collected at a uranium mill

Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

Science.gov (United States)

Smith-Schmitz, Sarah E.; Appold, Martin S.

2018-03-01

Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba

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.

Ore microscopy applied to beneficiation

International Nuclear Information System (INIS)

Hagni, R.D.

1978-01-01

Ore microscopy can be an important adjunct to beneficiation, because it can be used not only to predict mill problems of undeveloped ore deposits but to identify the causes for the loss of minerals in the products of operating mines and mills. Mineral distribution among various mill products can be determined by examining polished sections prepared from samples obtained from each step of the beneficiation process. The degree of liberation of each mineral can be quantitatively determined for each mill product by counting locked vs. free particles. For many beneficiation problems, the preparation of a few polished sections of carefully selected mill products can yield useful information, which the mill dressing engineer can effectively use to alleviate those problems

Study on Sumbawa gold ore liberation using rod mill: effect of rod-number and rotational speed on particle size distribution

Science.gov (United States)

Prasetya, A.; Mawadati, A.; Putri, A. M. R.; Petrus, H. T. B. M.

2018-01-01

Comminution is one of crucial steps in gold ore processing used to liberate the valuable minerals from gaunge mineral. This research is done to find the particle size distribution of gold ore after it has been treated through the comminution process in a rod mill with various number of rod and rotational speed that will results in one optimum milling condition. For the initial step, Sumbawa gold ore was crushed and then sieved to pass the 2.5 mesh and retained on the 5 mesh (this condition was taken to mimic real application in artisanal gold mining). Inserting the prepared sample into the rod mill, the observation on effect of rod-number and rotational speed was then conducted by variating the rod number of 7 and 10 while the rotational speed was varied from 60, 85, and 110 rpm. In order to be able to provide estimation on particle distribution of every condition, the comminution kinetic was applied by taking sample at 15, 30, 60, and 120 minutes for size distribution analysis. The change of particle distribution of top and bottom product as time series was then treated using Rosin-Rammler distribution equation. The result shows that the homogenity of particle size and particle size distribution is affected by rod-number and rotational speed. The particle size distribution is more homogeneous by increasing of milling time, regardless of rod-number and rotational speed. Mean size of particles do not change significantly after 60 minutes milling time. Experimental results showed that the optimum condition was achieved at rotational speed of 85 rpm, using rod-number of 7.

Developments in the management of radioactive waste from the mining and milling of radioactive ores

International Nuclear Information System (INIS)

Crawley, H.

1990-01-01

The philosophy of a waste management system is discussed. The origins of the various wastes from the mining and milling processes are outlined and the development of a waste management program described. The technical aspects of a waste management plan, namely water management systems, waste rock and ore stockpile management, tailings impoundment and decommissioning and rehabilitation are discussed in detail. 12 refs., 4 tabs, 15 figs

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

Directory of Open Access Journals (Sweden)

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

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

Dose conversion factors for inhalation applicable to the mining and milling of radioactive ores

International Nuclear Information System (INIS)

Hartley, B.M.

1992-01-01

The ICRP recommended revised dose limits for exposure to ionising radiation in November 1990. As well as reducing the annual occupational dose equivalent limit to an average of 20 mSv over 5 years, modified organ weighting factors were recommended, reflecting improved understanding of cancer risk factors for tissues and organs. The adjustment of weighting factors means that derived air concentrations conversion factors and annual limits on intake for exposure to airborne radionuclides are not simply modified by the ratio of the old to the new limits. A recalculation of these factors for radionuclides of interest in the mining and milling of radioactive ores is presented. A computer program for this purpose, based on the ICRP 30 inhalation model, is described. Rapid calculations of dose conversion factors are possible for the naturally occurring radionuclides in the 235 U, 238 U and 232 Th decay chains for which data are given in the supplements to ICRP 30. 7 refs., 12 tabs., 5 figs

Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

International Nuclear Information System (INIS)

Guillaume, B.; Charron, S.

2000-01-01

Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)

Chevron's Panna Maria mill process description

International Nuclear Information System (INIS)

Anon.

1979-01-01

Key features of Chevron's Uranium Mill located near Panna Maria, Texas, are described. The mill is designed to process a nominal 2500 dry tons/day of uranium bearing ore containing 15% uncombined moisture. The following operations at the mill are highlighted: ore receiving, grinding, leaching, countercurrent decantation and tailings disposal, filtering, solvent extraction, solvent stripping, precipitation, drying, and packaging

Uranium mining and milling

International Nuclear Information System (INIS)

Floeter, W.

1976-01-01

In this report uranium mining and milling are reviewed. The fuel cycle, different types of uranium geological deposits, blending of ores, open cast and underground mining, the mining cost and radiation protection in mines are treated in the first part of this report. In the second part, the milling of uranium ores is treated, including process technology, acid and alkaline leaching, process design for physical and chemical treatment of the ores, and the cost. Each chapter is clarified by added figures, diagrams, tables, and flowsheets. (HK) [de

Mining and milling of uranium ore: Indian scenario

International Nuclear Information System (INIS)

Bhasin, J.L.

2001-01-01

The occurrence of uranium minerals in Singhbhum Thrust belt of Eastern India has been known since 1937. In 1950, a team of geologists of the Atomic Minerals Division was assigned to closely examine this 160 km long belt. Since then, several occurrences of uranium have been found and a few of them have sufficient grade and tonnage for commercial exploitation. In 1967, the Government of India formed Uranium Corporation of India Ltd., under the administrative control of the Department of Atomic Energy, with the specific objective of mining and processing of uranium ore and produce uranium concentrates. At present the Corporation operates three underground uranium mines, one ore processing plant with expanded capacity, and two uranium recovery plants. Continuing investigations by the Atomic Mineral Division has discovered several new deposits and favourable areas. The most notable is the large Domiasiat deposit of the sandstone type found in the State of Meghalaya. This deposit is now being considered for commercial exploitation using the in-situ leaching technology. (author)

Uranium milling costs

International Nuclear Information System (INIS)

Coleman, R.B.

1980-01-01

Basic process flowsheets are reviewed for conventional milling of US ores. Capital costs are presented for various mill capacities for one of the basic processes. Operating costs are shown for various mill capacities for all of the basic process flowsheets. The number of mills using, or planning to use, a particular process is reviewed. A summary of the estimated average milling costs for all operating US mills is shown

A review of the environmental impact of mining and milling of radioactive ores, upgrading processes, and fabrication of nuclear fuels

International Nuclear Information System (INIS)

Costello, J.M.; Davy, D.R.; Cattell, F.C.R.; Cook, J.E.

1980-01-01

The subject is discussed under the headings: uranium mining; milling of uranium ores; manufacture of uranium hexafluoride; uranium enrichment; fuel manufacture and fabrication; environmental impact (use of natural resources; effluents from fuel cycle operations; occupational health; public health); alternative fuel cycles; additional waste treatment. (U.K.)

Determination of uranium concentration in an ore sample using laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Kim, Y.-S.; Han, B.-Y.; Shin, H.S.; Kim, H.D.; Jung, E.C.; Jung, J.H.; Na, S.H.

2012-01-01

Laser-induced breakdown spectroscopy (LIBS) has been recognized as a promising technique for analyzing sensitive nuclear materials such as uranium, plutonium, and curium in a high-radiation environment, especially since the implementation of IAEA (International Atomic Energy Agency) safeguards. The uranium spectra of ore samples were quantitatively analyzed prior to analyzing sensitive materials in the nuclear industry. The purpose of this experiment is to extract quantitative information about the uranium in a uranium ore using a standard addition approach. The uranium ore samples containing different concentrations of U were prepared by mixing raw ore powder with natural uranium oxide powders. Calibration sets of 0.2, 0.4, 0.6, 0.8 and 1.0 wt.% uranium concentrations within the uranium ore sample were achieved. A pulsed and Q-switched Nd:YAG laser at a wavelength of 532 nm was used as a light source. An echelle spectrometer that covers a 190–420 nm wavelength range is used to generate a calibration curve and determine the detection limit of uranium in the ore matrix. The neutral atomic-emission peak at a wavelength of 356.659 nm indicated a detection limit of ∼ 158 ppm for uranium, and the uranium concentration was determined in a raw ore sample that has an unknown quantity of uranium. - Highlights: ► The feasibility of LIBS application to monitor uranium element was carried out. ► The detection limit of U in ore was determined by a standard additional approach. ► Quantitative analyses of U concentration in a natural uranium ore were performed.

The impact of bacteria of circulating water on apatite-nepheline ore flotation.

Science.gov (United States)

Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

2012-01-01

A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to γ-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores.

Assessing radiological impacts (exposures and doses) associated with the mining and milling of radioactive ores

International Nuclear Information System (INIS)

Williams, G.A.

1990-01-01

The basic units and concepts applicable to radiological assessment are presented. Data relevant to the assessment of radiological exposures from the mining and milling phases of uranium and thorium ores are discussed. As a guide to the assessment of environmental exposures to members of the public, concepts such as the critical group are defined. Environmental transport and exposure pathways are presented in general terms, together with a discussion of the use of mathematical models. The dose assessment procedures defined in the 1987 Code of Practice are described. 13 refs., 2 tabs., 1 fig

INAA of Zn and impurity elements in Zn ores and concentrates

International Nuclear Information System (INIS)

Op de Beeck, J.; De Norre, L.; Hoste, J.

1985-01-01

The present work concerns the analysis of zinc ores and concentrates. In the first place a procedure for the routine determination of fluorine in Zinc sulfide ores has been developed, based on activation with the fast neutrons of the isotope source. In the second place a procedure for the routine determination of Cadmium in Zinc ores has been developed and finally the routine determination of Zinc itself is at present being completed

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

Management of Radioactive Waste from the Mining and Milling of Ores. Safety Guide (Spanish ed.)

International Nuclear Information System (INIS)

2010-01-01

This Safety Guide provides recommendations and guidance on the safe management of radioactive waste resulting from the mining and milling of ores, with the purpose of protecting workers, the public and the environment from the consequences of these activities. It supplements Safety Standards Series No. WS-R-1, Near Surface Disposal of Radioactive Waste. Contents: 1. Introduction; 2. Administrative, legal and regulatory framework; 3. Protection of human health and the environment; 4. Strategy for waste management; 5. Safety considerations in different phases of operations; 6. Safety assessment; 7. Quality assurance; 8. Monitoring and surveillance; 9. Institutional control for the post-closure phase.

Origin of granite and mineralization of uranium ore field No.6210

International Nuclear Information System (INIS)

Xu Guoqing.

1987-01-01

Uranium ore field No.6210 is of granitic type. A lot of work about the origin of the granite and mineralization has been done by many geologists over the years, but the conclusion remains disputable. Some authors suggest that the granitic magma was derived from mantle, others maintain that it was resulted from partial melting of crustal materials. There are two main points of view about the genesis of mineralization: magmatic hydrothermal and vadose. Therefore, with the exception of field investigation, strontium, sulfur, oxygen, carbon and lead isotopes were studied. REE distribution pattern, chemical compositions of biotite and whole rocks were explored. In granite the values of δ 34 S scatter in the range from -0.5 to 2.5per mille with a mean value of 0.77per mille, the values of δ 18 O lie in the range from 7.59 to 13.0per mille with an average of 10.55per mille. The ratio of ( 87 Sr/ 86 Sr)i of whole rocks is 0.7197. Biotite index MF 8 pa. In ore deposits, the values of δ 34 S range from -1.2 to 4.6per mille with a mean value of 1.52per mille, the values of δ 18 O fall in the range from -9.88 to 12.02per mille with an average amount of 3.56per mille, the values of δ 13 C are in the narrow range between -7.15 and -9.79per mille with an average of -8.96per mille and the ratios of 206 Pb/ 204 Pb 208 Pb/ 204 Pb < 39.5. Therefore, by the sulfur, carbon and lead isotopes, it is shown that the ore-forming solution in the ore field is magmatic hydrothermal, but by the oxygen isotope, it is implicated that after the fromation of hydrothermal ineralization, the ore deposits were reformed by meteoric water

Status Report from Canada [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Thunaes, A [Eldorado Mining and Refining Ltd., Ottawa (Canada)

1967-06-15

The Canadian production of uranium increased in a spectacular manner during the period 1955-1959 from 1000 to 15 500 tons U{sub 3}O{sub 8} per year. Since 1959 the production has declined to the 1966 level of 3900 tons U{sub 3}O{sub 8} per year; stretch-out of contracts and government stockpiling programmes has made the decline gradual, and is maintaining the current rate of production until 1970. Nineteen mills were in operation during the period of peak production but only three are operating today. Ten mills were shut down and dismantled because of exhaustion of ore bodies or because the operation was uneconomical; six mills are maintained in stand-by condition. The total daily capacity of mills in operation or standing by is about 28 000 tons ore, but some of these mills would not be reopened unless an appreciable increase in uranium price occurs. The tide of uranium demand is about ready to turn and prospecting for uranium is very active this year, particularly in the Elliot Lake and Beaverlodge areas. The estimates for uranium demand in 1975-1980 are such that new ore will have to be found and developed, and new treatment plants must be built. The new ore that is found will likely be of lower grade or more expensive to mine than most of the current proven reserves in Canada and the most efficient methods of treatment will be needed to avoid excessive increases in production costs. This seems an opportune time to review Canadian milling of uranium ore, the improvements that have been made and development work towards further improvements.

Safety and radiation protection in mining and milling facilities

Energy Technology Data Exchange (ETDEWEB)

Magalhaes, Maisa H.; Schenato, Flavia; Cruz, Paulo R., E-mail: maisahm@cnen.gov.br, E-mail: schenato@cnen.gov.br, E-mail: pcruz@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Xavier, Ana M., E-mail: axavier@cnen.gov.br [Comissao Nacional de Energia Nuclear (ESPOA/CNEN-RS), Porto Alegre, RS (Brazil). Escritorio de Porto Alegre

2011-07-01

Federal Legislation in Brazil establishes that the Brazilian Nuclear Energy Commission - CNEN - is responsible for the surveillance of the industrialization of nuclear ores and the production and commerce of nuclear materials in such way that activities such as buying, selling, import and export, are subject to previous licensing and surveillance. Regulation CNEN-NN-4.01 on Safety and Radiation Protection in Mining and Milling Facilities of conventional ores containing naturally occurring radioactive materials, NORM, was issued in 2004 establishing both a methodology for classification of these facilities into three Categories, taking into account both the contents of uranium and thorium in the ores and the applicable radiation and safety requirements based on a graded approach. Although the lack of a licensing process in the above mentioned Regulation made its implementation a difficult task, CNEN, by means of an initial survey, identified ca. 30 mining and milling industries of conventional ores containing uranium and thorium with concentrations above 10 Bq/g. More recently, a new juridical understanding of the legislation concluded that CNEN must issue licences and authorizations for the possession and storage of all ores with uranium and thorium concentrations above exemption levels. A proper surveillance programme encompassing 13 of these mining facilities was then put forward aiming at the improvement of their safety and radiation protection. This article presents an overview of NORM exploitation in Brazil and put forward suggestions for achieving viable solutions for the protection of workers, general public and environment from the effects of ionizing radiation. (author)

Leaching of U, 230Th and 226Ra from Saskatchewan uranium ore after removing clay

International Nuclear Information System (INIS)

Muthuswami, S.V.; Mohd Yunus, M.Z.; Mohamad Nor, M.I.; Kassim, Z.A.; Nirdosh, I.

1993-01-01

Distribution of U, 230 Th and 226 Ra in various size fractions in a typical Saskatchewan uranium ore and its resultant mill tailings indicated that less than 4% of these radionuclides were present in the fine ≤ 45 μm) size fraction in the ore whereas their concentration in the similar size fraction in the tailings was > 80%. Removal of clay minerals from the ore by flotation was unsuccessful whereas sedimentation gave nearly complete removal. Leaching of 230 Th from the ore before and after removing clay minerals indicated that dissolution of 230 Th was mproved at higher E h and acidity of the leaching medium and that it was independent of the presence of clay minerals in the ore. (orig.) [de

The distribution of naturally occurring radionuclides from ores processing to the environment - a case study of milling and treatment of ores for gold in Golden Star Resources of Bogoso Prestea Limited

International Nuclear Information System (INIS)

Gbadago, J.K.

2010-01-01

and Cd exceeded world permissible levels for industrial and mining lands. The estimated enrichment factor obtained suggested that the mines premises and critical group's soil are enriched with toxic elements Sn, Ba, Co, Cr, As, Hg, Sb and Cd. The average radionuclide series activity concentrations in the de-silted sediments of the run-off for 40 K, 238 U- and 232 Th-series were found to be higher than the operational tailing storage facilities. Relatively high concentrations of Ba, Cr and K in the sediments were also observed. This was an indication that the radionuclides and heavy metals are accumulating along the path of the run-off. The dose rate, annual effective dose equivalent, radium equivalent, external and internal hazard indices estimated for the de-silted sediments which were likely to be used as building materials were found to be lower than their respective permissible limits. Generally, the environmental impact of radionuclides distributed is expected to be low in this mining environment. The study showed that in the milling and processing of ores, both physical and chemical processing stages enhanced radionuclides and heavy metals but the enhancement was more significant in multiple chemical processing stages. However, the magnitude of enhancement depended on the total quality control of the process and ore grades used. (au)

Recent Developments in the Treatment of Uranium Ores from the Elliot Lake District

Energy Technology Data Exchange (ETDEWEB)

Downes, K W [Extraction Metallurgy Division, Department of Mines and Technical Surveys, Ottawa (Canada)

1967-06-15

A summary of the results obtained during investigations on the treatment of uranium ores from the Elliot Lake district in the laboratories of the Mines Branch, and of developments in operating procedures introduced in the uranium mills in the Elliot Lake district, is presented. Concentration of Elliot Lake ore on a pilot-plant scale by a combined gravity-flotation procedure yielded a 90% recovery of uranium at a ratio of concentration of 2.4 to 1.0. The mineralogical composition of the ore, the flow sheet used and the reagents employed are described. An approximate cost estimate indicates that, although the capacity of an existing uranium leaching plant would be doubled by introducing the procedure, the production cost per pound of U{sub 3}0{sub 8} would not be affected. Bacterial leaching of Elliot Lake ore on a laboratory scale yielded, under favourable conditions, extractions of 90 per cent in 5 weeks, and of 95 per cent in 15 weeks. The conditions that were found to influence the leaching results are outlined, and the effects of the leaching solutions are discussed. The purification of ion exchange eluates by liquid-liquid extraction, using tri-n-butyl phosphate, dibutyl butylphosphonate and tri-capryl amine in a continuous process, yielded solutions from which refined ammonium diuranate was precipitated using gaseous ammonia. The effectiveness of the three extractants is discussed, and the effects of the procedures employed on the production costs per pound of U{sub 3}O{sub 8} is estimated. Some improvements in operating procedures introduced in the Elliot Lake district uranium mills are briefly described, and their effects on the operations are indicated. Present methods of controlling radiological pollution of drainage waters by uranium mill tailings are outlined. (author)

NRC's limit on intake of uranium-ore dust

International Nuclear Information System (INIS)

McGuire, S.A.

1983-04-01

In 1960 the Atomic Energy Commission adopted an interim limit on the intake by inhalation of airborne uranium-ore dust. This report culminates two decades of research aimed at establishing the adequacy of that limit. The report concludes that the AEC underestimated the time that thorium-230, a constituent of uranium-ore dust, would remain in the human lung. The AEC assumed that thorium-230 in ore dust would behave like uranium with a 120-day biological half-life in the lung. This report concludes that the biological half-life is actually on the order of 1 year. Correcting the AEC's underestimate would cause a reduction in the permitted airborne concentration of uranium-ore dust. However, another factor that cancels the need for that reduction was found. The uranium ore dust in uranium mills was found to occur with very large particle sizes (10-micron activity median aerodynamic diameter). The particles are so large that relatively few of them are deposited in the pulmonary region of the lung, where they would be subject to long-term retention. Instead they are trapped in the upper regions of the respiratory tract, subsequently swallowed, and then rapidly excreted from the body through the gastrointestinal tract. The two effects are of about the same magnitude but in opposing directions. Thus the present uranium-ore dust intake limit in NRC regulations should provide a level of protection consistent with that provided for other airborne radioactive materials. The report recalculates the limit on intake of uranium-ore dust using the derived air concentrations (DAC) from the International Commission on Radiological Protection's recent Publication 30. The report concludes that the silica contained in uranium-ore dust is a greater hazard to workers than the radiological hazard

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.

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...

Correlation of radioactive waste treatment costs and the environmental impact of waste effluents in the nuclear fuel cycle for use in establishing ''as low as practicable'' guides: milling of uranium ores

International Nuclear Information System (INIS)

Sears, M.B.; Blanco, R.E.; Dahlman, R.C.; Hill, G.S.; Ryon, A.D.; Witherspoon, J.P.

1975-05-01

A cost-benefit study was made to determine the cost and effectiveness of radioactive waste (radwaste) treatment systems for decreasing the release of radioactive materials from model uranium ore processing mills, and to determine the radiological impact (dose commitment) of the released materials on the environment. The study is designed to assist in defining the term ''as low as practicable'' in relation to limiting the release of radioactive materials from nuclear facilities. The base case model mills are representative of mills which will process a major fraction of the ore in the next 20 years. Each mill processes 2,000 short tons of ore per day. Additional radwaste treatment techniques are applied to the base case mill and the waste tailings area in a series of case studies to decrease the amounts of radioactive materials released and to reduce the radiological dose commitment to the population in the surrounding area. The cost for the added waste treatment operations and the corresponding dose commitment are calculated for each case. In the final analysis, radiological dose is plotted vs the annual cost for treatment of the radwastes. The status of the radwaste treatment methods used in the case studies is discussed. Much of the technology used in the advanced cases will require development and demonstration and is not suitable for immediate use. The methodology used in estimating the costs, detailed calculations, and tabulations are presented in ORNL-TM-4903, Volume 2. The methodology and assumptions for the radiological doses are found in ORNL-4992. (U.S.)

Preliminary study of flotation behavior of Besham Lead-Zinc ore

International Nuclear Information System (INIS)

Khan, M.M.; Din, F.; Rafiq, M.

2001-01-01

This preliminary study examines the flotation behavior of the mineral galena from Besham Lead-Zinc ore samples with reference to the particle size, collector types such as Ethyl and Propyl xanthates and depressants. The comminution of the as mined ore was carried out in the laboratory jaw crusher and disc mill as well as in a laboratory ball mill. The material having size range between-90 microns and +63 microns was selected for flotation studies. (author)

Technology of Polish copper ore beneficiation – perspectives from the past experience

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Wieniewski Andrzej

2016-01-01

Full Text Available The paper describes the main types of existing copper deposits in the world and the most common enrichment technologies. The characteristic elements of the current flowsheet of the Polish ore beneficiation were discussed together with the reasons for using them. The paper presents a perspective flowsheet based on more than 50-years of experience in beneficiation of Polish copper ore. The main elements of proposed technology are: leaving in justified cases the division of ore into fractions of increased sandstone and carbonate ores content, flotation in the milling circuit as part of the effective preparation of the ore to rougher flotation, intensive rougher flotation, classic cleaning system, processing of the middlings with grinding system in new type mills, classification and flotation with outlet of final tailings.

Juuru Mihkli Kiriku Oreli Fond võttis endale uue ülesande / Tauno Kibur

Index Scriptorium Estoniae

Kibur, Tauno

2009-01-01

Oreli fond on võtnud ülesandeks restaureerida koguduse ajalooline pastoraat. Hoone eskiisi tegi Raivi Juks. Oreli restaureerimist ja tulemust jääb fikseerima Juuru oreli plaat, mille muusikapalad mängis sisse Kristel Aer

Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

Energy Technology Data Exchange (ETDEWEB)

Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

1980-03-01

High surface soil concentrations of /sup 226/Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer.

Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

International Nuclear Information System (INIS)

Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

1980-03-01

High surface soil concentrations of 226 Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer

A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler.

Science.gov (United States)

Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Andrew, Michael E

2006-03-01

Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass

Current uranium mill licensing issues

International Nuclear Information System (INIS)

Scarano, R.A.

1977-01-01

The problems encountered to insure environmentally safe mining and milling of uranium ores are reviewed. Emphasis is placed on the management of tailings resulting from milling operations. It is pointed out that although the concentration of radioactivity in the tailings is relatively low, control measures are necessary because of the large quantities involved and because of the long half-life of the parent radionuclides present. The major concerns with mill tailings are radon release to the atmosphere and isolation of the tailings from the human environment. Since it is anticipated that the amount of tailings created by the year 2000 will be more than an order of magnitude greater than the quantities that have been generated during the past 30 years, it is recommended that all mill tailings storage areas be located remote from public contact and in areas such that disruption and dispersion by natural forces and seepage of toxic materials into ground water systems are reduced to the maximum extent achievable. Technical issues that receive attention during the NRC licensing process for uranium mills and the preparation of environmental impact statements are discussed briefly

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,.

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

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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.

Radiation protection of workers in mining and processing of uranium ore

International Nuclear Information System (INIS)

Khan, A.H.; Sahoo, S.K; Puranik, V.D.

2003-01-01

Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at the site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body based on the international standards recommended by the ICRP and the IAEA are followed. In the uranium mines, external gamma radiation, radon and airborne activity due to radioactive dust are monitored. Similarly, in the uranium ore processing mill, gamma radiation and airborne radioactivity due to long-lived α-emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the area and personal monitoring data. It has been observed that the average radiation dose to workers has been below 10 mSvy -1 and all exposures are well below 20 mSvy -1 at all stages of operations. Adequate ventilation is provided during mining and ore processing operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper. (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)

Influence of liberation of sulphide minerals on flotation of sedimentary copper ore

Directory of Open Access Journals (Sweden)

Bakalarz Alicja

2017-01-01

Full Text Available Ore liberation is one of the most important parameter in mineral processing, especially in flotation. To separate the valuable components from gangue minerals, it is necessary to liberate one from others. It is achieve primarily through crushing and grinding. These stages are one of the most expensive of mineral production. It is important to determine the adequate mineral liberation which would result in huge savings in the overall cost of flotation plant. The aim of the paper was the analysis of the influence of milling time on the laboratory flotation of the copper ore from stratiform Polish deposit. Three different milling time of copper ore in laboratory ball mill was applied. The flotation results were presented as the recovery-recovery and grade-recovery upgrading curves. The liberation of sulphides and the particle size of sulphides in flotation product were analysed and compared.

British strong-acid leach process targeted at refractory uranium ores

International Nuclear Information System (INIS)

Anon.

1975-01-01

The UKAEA-patented strong-acid leach process for refractory U ores is briefly outlined with emphasis on its variations from the conventional dilute-acid process and the projected economics for a processing plant using this process. The process uses 6N H 2 SO 4 with a sharply reduced leaching time over conventional processes. The solubilized U is removed by percolation and the use of only about 10 percent liquid produces less effluent. Conventional processing plant equipment can be used except at the feed preparation, acid mixing, curing, and washing stages. Ore can be processed at larger grain sizes and the milling is done in a dry rod mill. Alternatives to the percolation removal of U are listed. Other work being done by UKAEA on U recovery from ores is briefly indicated. (U.S.)

Chapter 2: uranium mines and mills

International Nuclear Information System (INIS)

O'Connell, W.J.

1983-03-01

This chapter will be included in a larger ASCE Committee Report. Uranium mining production is split between underground and open pit mines. Mills are sized to produce yellowcake concentrate from hundreds to thousands of tons of ore per day. Miner's health and safety, and environmental protection are key concerns in design. Standards are set by the US Mine Safety and Health Administration, the EPA, NRC, DOT, the states, and national standards organizations. International guidance and standards are extensive and based on mining experience in many nations

Draft environmental statement related to the operation of Sand Rock Mill Project (Docket No. 40-8743)

International Nuclear Information System (INIS)

1982-03-01

After an assessment of concerns, alternatives, and the addition of license conditions as discussed below, the proposed action is the issuance of a Source and Byproduct Material License to Conoco, Inc. In July 1980, Conoco applied to the NRC for an NRC Source and Byproduct Material License to construct and operate in Cambell County, Wyoming, a uranium mill, associated with an open-pit mine, with an annual U 3 O 8 production rate of 715 MT (788 tons) per year. The proposed project would be located on 1604 ha (3963-acre) site approximately midway between Casper and Gillette and would lie about 0.8 km (0.5 mile) south of State Highway 387. The applicant proposes to receive and process ore from the Moore Ranch mine, which is located within the permit boundary. Other potential sources of ore include other Conoco mines, toll-milling customers, and joint venture partners in the immediate vicinity. A conventional sulfuric acid leach, countercurrent decantation (CCD), solvent extraction, ammonia precipitation circuit will be used to extract and concentrate the U 3 O 8 contained in the ore. Conoco proposes to operate 24 hours a day, 330 days a year, over the anticipated operating life of the mill (11.5 years). The total life of the mill--mine project is expected to be 17 to 18 years, including construction, operation and reclamation. 31 figs., 74 tabs

Uranium mining and milling sites in Argentina: environmental radiological monitoring (1980-1994)

International Nuclear Information System (INIS)

Bomben, A.M.; Gomez, J.C.; Oliveira, A.A.

1995-01-01

Environmental radiological monitoring in the vicinity of uranium mining and milling plants in Argentina is performed on a routine basis, in order to assess the possibility of significant environmental contamination due to uranium mill wastes and mill tailings of plants still operating or those where the exploitation have concluded. Dissolved natural uranium and 226 Ra concentrations in surface waters are measured in samples taken from rivers near the mills, according to a special monitoring plan set up for each facility. In addition, 222 Rn emanation rates from ore tailings are measured at times. In this paper the environmental radiological monitoring program results obtained for the 1980-1994 period are shown. From the data analyses it can be concluded that there are not significant differences for the concentrations of the radionuclides of interest, between the surface water samples taken from river location above and below the plants discharge points. Besides, no significant exposure results for the population living in the surrounding areas due to the uranium mining and milling plants operation or their wastes. (author). 2 refs., 5 figs

Cluff Lake mill operations - a historical review

International Nuclear Information System (INIS)

Schnell, H.A.; Doell, E.; Corpus, E.

2000-01-01

The Cluff Lake operation started uranium production in 1980 and has produced over 50 million pounds of uranium since that time. The plant started with high grade ore (+30% U) processing and went through a series of modifications to its present operating status: Phase 1 - High-grade ore (+30% U) processing with acid leach and iron cake precipitation followed by direct yellowcake precipitation. Lower grade ore was concentrated in a gravity circuit to +30% U; Phase 1 1/2 - Reprocessing Phase 1 gravity tailings (+1% U) in an acid leach circuit with solvent extraction purification prior to yellowcake precipitation; Reprocessing of the Phase 1 leach tails (58 g/t Au) to recover gold in a Cyanide/CIP circuit followed by additional uranium recovery, and destruction and recycle of cyanide by volatilization; and Phase 2 - Treatment of the lower grade ore (0.5 to 1% U) at an increased tonnage with an acid leach, CCD, SX circuit as it is found in the existing plant. This paper will review the various processing circuits used during the phases of the Cluff Lake Mill from first uranium production to the present operation. (author)

Development of Technology for Enrichment of Silver Containing Ores

Science.gov (United States)

Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

2016-10-01

-purification operations. On the basis of laboratory investigations for silver-containing ores of David-Gareji deposit the technological scheme is recommended which implies the ore milling to 82 % class -074 mm, flotation of the silver minerals and the barite flotation from the tails of this operation by two-fold re-purification of the rough concentrate. The optimal parameters of the receipt of the reagent regime are: potassium butylxantogenate and pine oil-in the silver flotation; sodium carbonate, liquid glass, “Baritol”- in the barite main flotation and liquid glass in the repurification operations. Silver concentrate containing 680 g/ton of silver by extraction of 92.21% and barite concentrate, content - 92.11%, extraction - 81.85% are obtained.

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)

Uranium mining and milling by Cogema environmental impact compared to 1 mSv limit

International Nuclear Information System (INIS)

Bernhard, S.; Daroussin, J.L.; Pfiffelmann, J.P.

1996-01-01

CEA then COGEMA have been operating mines and mills in France since 1948. Total production nears 70000 t of U in the concentrate which were contained in some 85 millions tons of ores (pulp and heap leaching). Many sites are now undergoing remediation and impact on the environment has always been a great concern. (author)

Fluorine concentrations of ore fluids in the Illinois-Kentucky district: Evidence from SEM-EDS analysis of fluid inclusion decrepitates

Science.gov (United States)

Kenderes, Stuart M.; Appold, Martin S.

2017-08-01

The Illinois-Kentucky district is an atypical occurrence of Mississippi Valley-type (MVT) mineralization that consists predominantly of fluorite rather than metal sulfide minerals. A long-standing assumption for the predominance of fluorite in the Illinois-Kentucky district is that the ore fluids there were anomalously rich in dissolved fluorine compared to typical sedimentary brines and other MVT ore fluids. This hypothesis is based on the unusual close temporal and spatial association of fluorine-rich ultramafic igneous rocks to MVT mineralization in the district, high K and Sr concentrations in the igneous rocks and in MVT ore-hosted fluid inclusions, a significant mantle 3He/4He component in ore-hosted fluid inclusions, and reaction path models that show titration of a HF-rich fluid into sedimentary brine is capable of producing a fluorite-dominated MVT ore mineral assemblage. The purpose of the present study was to test this hypothesis more directly by determining the fluorine concentration of the Illinois-Kentucky ore fluid through SEM-EDS analysis of evaporative solute mounds resulting from thermal decrepitation of fluid inclusions hosted in sphalerite. All 26 evaporative solute mounds from Illinois-Kentucky sphalerite samples analyzed contained detectable concentrations of fluorine of 1-4 weight percent. Based on calibration to standard solutions and previously published fluid inclusion major element concentrations, these solute mound fluorine concentrations correspond to fluid inclusion fluorine concentrations of about 680-4300 ppm, indicating that the Illinois-Kentucky ore fluids were quite rich in fluorine compared to typical sedimentary brines, which have fluorine concentrations mainly on the order of 1's to 10's of ppm. In contrast, solute mounds from sphalerite-hosted fluid inclusions from the Tri-State district did not contain fluorine in excess of the detection limit. The detection limit equates to an aqueous fluorine concentration between 87 and

Use of isotope ratios to assess sources of Pb and Zn dispersed in the environment during mining and ore processing within the Orlovka-Spokoinoe mining site (Russia)

International Nuclear Information System (INIS)

Dolgopolova, A.; Weiss, D.J.; Seltmann, R.; Kober, B.; Mason, T.F.D.; Coles, B.; Stanley, C.J.

2006-01-01

Element concentrations, element ratios and Pb and Zn isotope data are reported for different geologic samples (barren and ore-bearing granites and host rocks), technogenic products (ore concentrates and tailings) and biologic samples (lichens and birch leaves) from the Orlovka-Spokoinoe mining district, Eastern Transbaikalia, Russia, with the aim to trace the sources of Pb and Zn at a local level within the mining site. Lichens and birch leaves were used as receptors of contamination within the mining site. Pb/Zr and Zn/Zr values indicated Pb and Zn enrichment relative to host rocks. Zn isotope data of 15 geologic and 11 lichen samples showed different Zn isotopic signatures with the total range for the geologic suite of -0.4 per mille to +1.2 per mille and for lichens of +0.4 per mille to +1.4 per mille in δ 66 Zn relative to Lyon JMC Zn standard. The source of isotopically heavy Zn within the Orlovka-Spokoinoe mining site could be potentially associated with long-range atmospheric aerosols that also contributed Pb to the studied mining site. Our results demonstrated that Zn isotopes might be used as new tools for Zn source assessment

Sinterization of manganese ore tailings under natural air

Energy Technology Data Exchange (ETDEWEB)

Lima, M.M.F.; Souza, L.G.P.R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

2014-07-01

The manganese ore has wide application in metallurgy. However, from each of three hundred concentrations found, only one can be seen as a deposit. The aim of this study was to obtain and characterize a sinter from manganese ore tailing. The tailing was milled, classified (<400 ⧣) and calcinated (800°C - 3600s). The mixture had 12% moisture, 7 and 9% of activated charcoal. After homogenization, the sintering were carried out at 1140, 1145 and 1150°C during 1800, 7200 and 14400s at natural air. The sintered products were characterized by EDS analysis, BET surface area, apparent density, X-rays diffraction and SEM/EDS. The mass loss was approximately 14% and 16% in the calcination and sintering, respectively, due to the elimination of volatile products and water. The main phases characterized: SiO2, silicate with high content of manganese in the matrix and other silicates with different proportions of Ti, Na, Mn, Mg and Ca. (author)

3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

International Nuclear Information System (INIS)

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

2015-01-01

Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

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

Directory of Open Access Journals (Sweden)

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

Studies on uranium ore processing

International Nuclear Information System (INIS)

Suh, I.S.; Chun, J.K.; Park, S.W.; Choi, S.J.; Lee, C.H.; Chung, M.K.; Lim, J.K.

1983-01-01

For the exploitation of domestic uranium ore deposit, comprehensive studies on uranium ore processing of the Geum-San pit ore are carried out. Physical and chemical characteristics of the Geum-San ore are similar to those of Goe-San ore and the physical beneficiation could not be applicable. Optimum operating conditions such as uranium leaching, solid-liquid separation, solvent extraction and precipitation of yellow cake are found out and the results are confirmed by the continous operation of the micro-plant with the capacity of 50Kg, ore/day. In order to improve the process of ore milling pilot plant installed recently, the feasibility of raffinate-recycle and the precipitation methods of yellow cake are intensively examined. It was suggested that the raffinate-recycle in the leaching of filtering stage could be reduced the environmental contamination and the peroxide precipitation technique was applicable to improve the purity of yellow cake. The mechanism and conditions the third phase formation are thoroughly studied and confirmed by chemical analysis of the third phase actually formed during the operation of pilot plant. The major constituents of the third phase are polyanions such as PMosub(12)Osub(40)sup(3-) or SiMosub(12)Osub(40)sup(4-). And the formation of these polyanions could be reduced by the control of redox potential and the addition of modifier. (Author)

Radiological survey of the inactive uranium-mill tailings at the Spook site, Converse County, Wyoming

International Nuclear Information System (INIS)

Haywood, F.F.; Christian, D.J.; Chou, K.D.; Ellis, B.S.; Lorenzo, D.; Shinpaugh, W.H.

1980-05-01

Results of a radiological survey performed at the Spook site in Converse County, Wyoming, in June 1976, are presented. The mill at this site was located a short distance from the open-pit mine where the ore was obtained and where part of the tailings was dumped into the mine. Several piles of overburden or low-grade ore in the vicinity were included in the measurements of above-ground gamma exposure rate. The average exposure rate over these piles varied from 14 μR/hr, the average background exposure rate for the area, to 140 μR/hr. The average exposure rate for the tailings and former mill area was 220 μR/hr. Movement of tailings particles down dry washes was evident. The calculated concentration of 226 Ra in ten holes as a function of depth is presented graphically

Isolation of uranium mill tailings and their component radionuclides from the biosphere; some earth science perspectives

Science.gov (United States)

Landa, Edward

1980-01-01

Uranium mining and milling is an expanding activity in the. Western United States. Although the milling process yields a uranium concentrate, the large volume of tailings remaining contains about 85 percent of the radioactivity originally associated with the ore. By virtue of the physical and chemical processing of the ore and the redistribution of the contained radionuclides at the Earth's surface, these tailings constitute a technologically enhanced source of natural radiation exposure. Sources of potential human radiation exposure from uranium mill tailings include the emanation of radon gas, the transport of particles by wind and water, and the transport of soluble radionuclides, seeping from disposal areas, by ground water. Due to the 77,000 year half-life of thorium-230, the parent of radium-226, the environmental effects associated with radionuclides contained in these railings must be conceived of within the framework of geologic processes operating over geologic time. The magnitude of erosion of cover materials and tailings and the extent of geochemical mobilization of the contained radionuclides to the atmosphere and hydrosphere should be considered in the evaluation of the potential, long-term consequences of all proposed uranium mill tailings management plans.

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.

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

Directory of Open Access Journals (Sweden)

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.

Status Report from the United States of America [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R H [United States Atomic Energy Commission, Washington, D.C. (United States)

1967-06-15

The US uranium production rate has been dropping gradually from a high of 17 760 tons in fiscal year 1961 to a level of about 10 400 tons in fiscal year 1966. As of 1 January 1966, there were 17 uranium mills in operation in the USA compared with a maximum of 26 during 1961, the peak production year. Uranium procurement contracts between the USAEC and companies operating 11 mills have been extended through calendar year 1970. The USAEC contracts for the other six mills are scheduled to expire 31 December 1966. Some of these mills, however, have substantial private orders for production of uranium for nuclear power plants and will continue to operate after completion of deliveries under USAEC contracts. No new uranium mills have been brought into production since 1962. Under these circumstances the emphasis in process development activities in recent years has tended toward improvements that could be incorporated within the general framework of the existing plants. Some major flowsheet changes have been made, however. For example, two of the ore-processing plants have shifted from acid leaching to sodium carbonate leach in order to provide the flexibility to process an increasing proportion of ores of high limestone content in the tributary areas. Several mills employing ion exchange as the primary step for recovery of uranium from solution have added an 'Eluex' solvent extraction step on the ion exchange eluate. This process not only results in a highgrade final product, but also eliminates several metallurgical problems formerly caused by the chloride and nitrate eluants. Such changes together with numerous minor improvements have gradually reduced production cost and increased recoveries. The domestic uranium milling companies have generally had reserves of normal-grade ores well in excess of the amounts required to fulfil the requirements for their contracts with the USAEC. Therefore, there has been little incentive to undertake the processing of lower grade

Radiation legacy of the USSR enterprises for mining, milling and processing of uranium ores: Conservation, decommissioning and environmental rehabilitation

International Nuclear Information System (INIS)

Burykin, A.A.; Iskra, A.A.; Karamushka, V.P.

2002-01-01

The long-term operation of USSR uranium mining and milling enterprises produced a great volume of low level radioactive waste in the form of rock spoil heaps (181 million m 3 ), hydro-metallurgical plants tailings dumps (340 million m 3 ) and basins of mine waters (200 million m 3 ) with total activity of 25.1·10 15 Bq (670 kCi). The total area occupied by the dumps is about 180 km 2 . The paper presents brief characteristics of the activities of uranium ore mining enterprises located at the CIS countries' territories, their wastes' status and describes measures for rehabilitation and restoration of territories of the Soviet uranium mining and metallurgical complex. (author)

Semi-continuous on-line uranium ore analyzer

International Nuclear Information System (INIS)

Campbell, P.; Gurdy, E.M.; Hatchowski, L.

1984-01-01

The efficient process control of a uranium mill and its associated mining operation requires a nearly continuous knowledge of the uranium concentration in the ore. Generally, the approach is to use laboratory assays of grab samples from the mill feed belt. In some cases, elaborate and expensive systems have been used to ensure random sampling, but even with these systems, mass-balance discrepancies still exist. There is a requirement for an on-line instrument that can give a prompt, accurate analysis of a large portion of the feed stock. The authors have recently evaluated a laboratory system that achieves these goals using neutron activation and delayed neutron counting. The development of the on-line uranium ore analyzer is a consequence of previous work done at the Whiteshell Nuclear Research Establishment (WNRE) (Campbell et al., 1978 and 1981), and is based on the emission of delayed neutrons after the neutron irradiation of fissionable materials. The mechanism of delayed neutron emission has been described (Keepin, 1965), but briefly is as follows. The fission fragments resulting from irradiation are in an excited state. Certain of these delayed fission products, precursors, decay to a more stable state by the emission of a delayed neutron. The delayed neutrons can be divided into six groups with effective half-lives ranging from 0.2-55 sec. It is important to note that more than 50% of the delayed neutrons are emitted within the first 6 sec after irradiation; this has an influence on the design of the analysis instrument

Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia

International Nuclear Information System (INIS)

Keegan, Elizabeth; Kristo, Michael J.; Colella, Michael; Robel, Martin; Williams, Ross; Lindvall, Rachel; Eppich, Gary; Roberts, Sarah; Borg, Lars; Gaffney, Amy; Plaue, Jonathan; Wong, Henri; Davis, Joel; Loi, Elaine; Reinhard, Mark; Hutcheon, Ian

2014-01-01

In early 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. While searching the laboratory, they discovered a small glass jar labelled 'Gamma Source' and containing a green powder. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterize and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive range of parameters were measured, the key 'nuclear forensic signatures' used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine

Dense medium ore concentrates of Bois-Noirs; Minerais des bois noirs, concentres de milieu dense

Energy Technology Data Exchange (ETDEWEB)

Le Bris, J; Leduc, M

1959-01-20

The chemical treatment of uranium concentrates of Bois-Noirs ore obtained by heavy medium are discussed. The first part deals with sulfuric acid attack on the concentrate, and the second part with the separation of the solution from residues by filtration. A third part deals with this separation by decantation. The fourth part deals with the carbonation of the pickling solutions obtained. (author) [French] Le present rapport est relatif a l'etude du traitement chimique de concentres uraniferes de minerais des Bois-Noirs obtenus par milieu dense. Une premiere partie est consacree a l'attaque sulfurique des concentres, une deuxieme partie a Ia separation de Ia solution d'attaque des residus par decantation. Une quatrieme partie a la carbonatation des solutions d'attaque obtenues. (auteur)

Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

International Nuclear Information System (INIS)

Cross, F.T.; Palmer, R.F.; Busch, R.H.

1980-01-01

Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

Atomic-absorption determination of tantalum and niobium in ore concentrates

International Nuclear Information System (INIS)

Elinson, S.V.; Korovin, Yu.I.; Kuchumov, V.A.

1975-01-01

A flame atom-absorption method was developed for determining tantalum and niobium at their level greater than 5% in Ta-Nb ore concentrates. Flame was produced by a nitrous oxide-acetylene mixture. The optimal composition of a buffer (3 mg/ml) of iron was determined by the method of factorial planning of the experiment and steep ascention by gradient. The optimizing parameter in factorial planning was obtained from the difference of optical densities of Ta and Nb, by taking the average value for two solutions which had dissimilar total composition and which imitated the real composition of the ore concentrates, i.e., the value of (ΔD/Dsub(av))sub(Ta) or (ΔD/Dsub(av))sub(Nb). The optimization of analytical conditions corresponded to the condition (ΔD/Dsub(av))→ 0, which indicated that the chosen optimizing parameter also facilitated the attainment of maximum D values. The variation coefficient in the determination of Ta and Nb was respectively 0.8 and 1.4%. There was a good agreement between the results obtained in Ta analysis by the atom-absorption and the extraction-gravimetric methods, and in Nb analysis by the atom-absorption, differential spectrophotometric and x-ray fluorescence methods

Humeca Uranium Mill. Nuclear Regulatory Commission's final environmental statement

International Nuclear Information System (INIS)

1976-04-01

The Humeca Uranium Mill is a carbonate-leach uranium ore refining plant with a capacity of about 500 tons of ore per day. Although the present licensing action does not extend to mining, the statement considers the environmental impact of the combined mining and milling project to be conducted by Rio Algom Corporation. The environmental impact, including adverse and beneficial environmental effects of the Rio Algom Uranium Mill, is as follows. (1) Temporary (about 10 years) reassignment of use of about 120 acres of land out of the total 2,573 acres controlled by Rio Algom Corporation. (2) The removal of an estimated 8.4 million pounds of uranium concentrates as a natural resource. This material will eventually be used to produce approximately 6.09 x 10 6 megawatt-days of electricity. (3) Removal and diversion of approximately 100 gallons per minute of local groundwater. (4) Stimulation of the local economy through payment of taxes and direct employment of about 200 persons in San Juan County over the next 10 years. Rio Algom estimates they will pay out over $11 million in salaries over this period of time. (5) The creation of stabilized tailings piles covering about 45 acres involving approximately 1,850,000 tons of solids containing solidified waste chemical and radioactive uranium and its daughter products. (6) Discharge of small quantities of chemicals and radioactive materials (that are not expected to produce discernible effects) into the local environs

Radium, uranium and metals in acidic or alkaline uranium mill

International Nuclear Information System (INIS)

Somot, St.

1997-01-01

Uranium mill study sites have been chosen in function of their different characteristics: deposits age, treatment nature (alkaline or acid), mill origin. The realization of specific drilling allowed the simultaneous study of the interstitial water and the solid fraction of samples, cut at determined deep. A radiation imbalance between 230 Th and 226 Ra is observed in the acid treatment residues. The trace elements concentration spectrum is directly bound to the nature of the ore. Diamagnetic evolutions are observed in residues. The uranium concentrations are higher in carbonated waters than in calcic sulfated waters. The selective sequential lixiviation showed that the 226 Ra activity of the interstitial water is controlled by the Gypsum in acid treatment residues. In other hand in the alkaline treatment waters, the carbonates occur. The Ra retention is largely bound to the Fe and Mn oxy-hydroxides. (A.L.B.)

Radioactive Ores and Concentrates (Packaging and Transport) Act 1980. No 26 of 1980

International Nuclear Information System (INIS)

1980-01-01

This Act, which regulates the packaging, storage and transport of radioactive ores and concentrates lays down a detailed licensing system for such materials and prescribes the duties of the Chief Inspector responsible for implementation of the Act. (NEA) [fr

Radiological survey of the inactive uranium-mill tailings at Green River, Utah

International Nuclear Information System (INIS)

Haywood, F.F.; Christian, D.J.; Ellis, B.S.; Hubbard, H.M. Jr.; Lorenzo, D.; Shinpaugh, W.H.

1980-03-01

The uranium-mill tailings at Green River, Utah, are relatively low in 226 Ra content and concentration (20 Ci and 140 pCi/g, respectively) because the mill was used to upgrade the uranium ore by separating the sand and slime fractions; most of the radium was transported along with the slimes to another mill site. Spread of tailings was observed in all directions, but near-background gamma exposure rates were reached at distances of 40 to 90 m from the edge of the pile. Water erosion of the tailings is evident and, since a significant fraction of the tailings pile lies in Brown's Wash, the potential exists for repetition of the loss of a large quantity of tailings such as occurred during a flood in 1959. In general, the level of surface contamination was low at this site, but some areas in the mill site, which were being used for nonuranium work, have gamma-ray exposure rates up to 143 μR/hr

Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations

Science.gov (United States)

Saramak, Daniel; Krawczykowska, Aldona; Młynarczykowska, Anna

2014-10-01

This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 2: Small mammal food chains and bioavailability

Energy Technology Data Exchange (ETDEWEB)

Thomas, P.A.

2000-06-01

Food chain transfer through the soil-vegetation-small mammal food chain was measured by concentration ratios (CRs) for uranium, {sup 226}Ra, {sup 210}Pb, and {sup 210}Po at three sites near the Key Lake uranium mill in northern Saskatchewan. Plant/soil CRs, animal carcass/GI tract CRs, and animal/soil CRs were depressed at sites impacted by mill and tailings dusts relative to a nearby control site. Thus, radionuclides associated with large particulates in tailings and/or ore dusts may be less bioavailable to terrestrial plants and animals than natural sources of radioactive dust. These results show that reliance on default food chain transfer parameters, obtained from uncontaminated terrestrial ecosystems, may overpredict impacts at uranium mine and mill sites. Given the omnivorous diet of small mammals and birds, animal/soil CRs are recommended as the most cost-effective and robust means of predicting animal concentrations from environmental monitoring data at uranium mill facilities.

Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 2: Small mammal food chains and bioavailability

International Nuclear Information System (INIS)

Thomas, P.A.

2000-01-01

Food chain transfer through the soil-vegetation-small mammal food chain was measured by concentration ratios (CRs) for uranium, 226 Ra, 210 Pb, and 210 Po at three sites near the Key Lake uranium mill in northern Saskatchewan. Plant/soil CRs, animal carcass/GI tract CRs, and animal/soil CRs were depressed at sites impacted by mill and tailings dusts relative to a nearby control site. Thus, radionuclides associated with large particulates in tailings and/or ore dusts may be less bioavailable to terrestrial plants and animals than natural sources of radioactive dust. These results show that reliance on default food chain transfer parameters, obtained from uncontaminated terrestrial ecosystems, may overpredict impacts at uranium mine and mill sites. Given the omnivorous diet of small mammals and birds, animal/soil CRs are recommended as the most cost-effective and robust means of predicting animal concentrations from environmental monitoring data at uranium mill facilities

Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources

Energy Technology Data Exchange (ETDEWEB)

Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Patrick Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-03-11

Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.

Investigation of spectral interference effects on determination of uranium concentration in phosphate ore by inductively coupled plasma optical emission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bachari, Ayoob H.; Jalali, Fatemeh; Alahyarizadeh, Ghasem [Tehran Univ. (Iran, Islamic Republic of). Engineering Dept.

2017-04-01

Effects of spectral interferences on determination of the uranium concentration in phosphate ore were investigated by inductively coupled plasma optical emission spectroscopy (ICP-OES). Eleven high intensity emission lines including four lines recommended by ICP-OES apparatus were chosen to determine the uranium concentration. The ore samples were collected from phosphate acid producing industry in the south of Iran. Three different acid combinations [(HNO{sub 3}:HCl:HF-2:6:2), (H{sub 3}PO{sub 4}:H{sub 2}SO{sub 4}:HF-3:3:3), (HNO{sub 3}:H{sub 2}O{sub 2}:HF-4:2:2)] used in microwave digestion method to explore the spectral interference effects in different solvent environments. The results showed that the trusty uranium concentration, obtained in the 367.007 nm, 386.592 nm, 389.036 nm and 409.014 nm by second acid digestion method which were 0.665 ppm, 0.972 ppm, 0.670 ppm and 0.801 ppm, respectively. Although the line of 409.014 nm was reported as the best line for determining of the uranium concentration in several literatures, the results showed that this line has a significant spectral interference with vanadium in some ores which should be considered in determining of the uranium concentration. Spectral interference effects of some elements which have high concentrations in the phosphate ore including Ca, Fe, Mg, Pb, V, Mn, and Ti on the line intensities were also investigated. Results indicated that the chosen elements affect emission intensities of all of 11 lines. They also indicated that the line of 409.014 nm provides a trusty precision in the determination of the uranium concentration in the ore sample with low vanadium concentration (at least, U/V ratio of 1:5). Results show that the line of 409.014 nm provides acceptable precision with some corrections in comparison with other selected lines. For instance in high concentrations of other elements including Fe and Ti in the ore samples, strong influences on the line intensities of the 367.007 nm (by Fe

Evaluation of particle dispersal from mining and milling operations using lead isotopic fingerprinting techniques, Rio Pilcomayo Basin, Bolivia

International Nuclear Information System (INIS)

Miller, Jerry R.; Lechler, Paul J.; Mackin, Gail; Germanoski, Dru; Villarroel, Lionel F.

2007-01-01

Mining and milling of ores from the Cerro Rico de Potosi precious metal-polymetallic tin deposits of Bolivia have led to severe contamination of water and sediments of the Rio Pilcomayo drainage system. Lead (Pb) isotopic data were used in this study to first document downstream dispersal patterns of Pb contaminated sediment within the channel of the Rio Pilcomayo, and then to determine the relative contribution of Pb from Cerro Rico within alluvial terrace soils that are used for agriculture. The concentration and isotopic composition of Pb within channel bed sediments differed significantly between 2000, 2002, and 2004. These differences presumably reflect changes in the type of ore mined and milled at Cerro Rico, and alterations in dispersal and grain-size dilution mechanisms associated with interannual variations in rainfall and runoff. Within agricultural terrace soils, both Pb concentrations and the percentage of Pb from Cerro Rico: (1) semi-systematically decrease downstream, (2) were found to decrease with terrace height above the channel, and (3) reflect the use of contaminated irrigation water. In upstream reaches (within 30 km of the mills), Pb from mining represents the most significant Pb source, accounting for more than 80% of Pb in the examined agricultural fields. At Sotomayor, located approximately 170 km from the mills, the relative contribution of Pb from Cerro Rico is highly variable between fields, but can be significant, ranging from approximately 15% to 35%. The analysis demonstrates that Pb isotopic ratios can be used to effectively trace contaminated particles through river systems and into adjacent alluvial soils, even where multiple Pb sources exist and Pb concentrations are similar to background values

Crusher isolation to keep Key Lake mill dust free

International Nuclear Information System (INIS)

Turnbull, Andy.

1982-01-01

About a mile of four-inch pipe will virtually eliminate dust in the mill area of the new Key Lake uranium mine when production begins in the summer of 1983. The ore from the pit will be crushed beside the pit, wetground, and piped as a slurry to the mill, which will be isolated from dust-producing processes. The pipeline will carry about 780 tons per day and will replace about one and half haulage trucks. The mill will be able to extract more than 99 percent of the uranium from the ore, which contains about 2.5 to 2.7 percent uranium. The life span of the mine is planned to be about 20 years, with a production of 12 million pounds of yelloscake a year. There will never be a townsite at Key Lake because personnel are to be flown in for seven days of 11-hour shifts, then fly out for seven days off. The tailings pond under construction is designed for sastes which will soon become dry and solid due to the high gypsum content of the ore. Process water from the mine will be held in one of five ponds for a day and released only after monitoring. An ammonium sulfate crystallization plant on the site will use waste from the uranium precipitation process to make fertilizer. The mine and mill are costing about $500 million to develop and bring into production

Experience Gained from the Former Uranium Ore Processing and the Remediation of the Legacy Site in Hungary

Energy Technology Data Exchange (ETDEWEB)

Csövári, M.; Földing, G.; Berta, Zs.; Németh, G., E-mail: csovarimihaly@mecsekoko.hu [MECSEK-ÖKO Zrt, Pécs (Hungary)

2014-05-15

Uranium explorations in Hungary started 1953. By 1957 the uranium ore reserves were confirmed and the feasibility of mining in the Mecsek Mountains demonstrated by opening the first shaft. In 1962 the mill was built. The mining and processing of the uranium ore were terminated in 1997 mainly on economical reasons. The remediation of the site has started immediately and had been practically finished in 2008. The paper summarises the remediation work, and some lessons learned from the former mill practice, and from the remediation activity. (author)

Measurement of Natural Radioactive Nuclide Concentrations and the Dose Estimation of Workers Originated from Radon in Manganese Ore Mine

International Nuclear Information System (INIS)

Mansour, N.A.; Hassan, N.M.; Blasy, M.R.

2013-01-01

Manganese ore is widely used in many industries. Such as ore contain natural radioactive nuclides at various concentrations. If this ore contain high concentrations of natural radioactive nuclides, workers handling them might be exposed to significant levels of radiation. Therefore it is important to determine the radioactive nuclides in this ore. Also the regulation of radon concentration at workplaces has gained an accentuated importance in all countries. Nevertheless, at this time there is no globally accepted workplace protocol that sets out safe radon concentration values. In this study the radon concentration measured by using an Alpha Guard radon monitor, the equilibrium factor which was greater than the value given in literature, effective radiation dose, which are necessary for the exact estimation of the radiation dose originating from radon. The regulation of radon concentration at workplaces has gained an accentuated importance in all countries. Approach: The natural radionuclides ( 238 U, 232 Th and 40 K) contents of manganese ore samples collected from Umm Bogma, southwest Sinai and from the mountain access Hamid South Eastern Desert, Egypt have been determined by low background spectroscopy using hyper-pure germanium (HPGe) detector. Results: The mean activities due to the three radionuclides ( 238 U, 232 Th and 40 K) were found to be 1500±65, 490±65 and 364±45 Bqkg -1 , respectively. The absorbed dose rate due to the natural radioactivity in samples under investigation ranged from 1522±45 → 1796±43 nGyh -1 . The radium equivalent activity varied from 3807±114→ 4446±133 Bqkg -1 .The representative external hazard index values for the corresponding samples are also estimated. Conclusion: The results of this assessment obtained by the gamma-ray spectroscopic analysis, have indicated that the levels of natural radioactivity were lower than the international recommended limits.

Wastes from former mining and milling activities in Tajikistan

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2012-01-01

This article is devoted to wastes from former mining and milling activities in Tajikistan. Currently, the serious radiological and ecological problems in Tajikistan are uranium mining and milling activities consequences overcoming which intensively developed during the soviet period. After the collapse of USSR, the uranic ores extraction in Tajikistan stopped due to deposit's output completion on the territory of the republic. Remediation of mining and milling activities' sites became the most urgent once all mines were closed.

Technologies for processing low-grade uranium ores and their relevance to the Indian situation

International Nuclear Information System (INIS)

Murthy, T.K.S.

1991-01-01

The technology for uranium ore processing is well established. Various estimates have shown that on a global basis uranium resources are adequate to meet the forseeable demand. The Indian resources are estimated to be about 60,000 t U. The grade of the ores is low and the individual deposits are small. The nature of the deposits, precarious resources position and relatively small capacity of the mines do not permit the country to take advantage of large throughputs in the mill to achieve substantial cost reduction. However by resorting to as high a scale of milling as the mines would permit, by reducing the loss of solubilised uranium after leaching and by undertaking production of nuclear grade final product at the mill site, significant though not a major, economic benefit can be derived. (author). 2 figs., 3 tabs

Non-radiological contaminants from uranium mining and milling at Ranger, Jabiru, Northern Territory, Australia.

Science.gov (United States)

Noller, B N

1991-10-01

Protection from the hazards from radioactivity is of prime importance in the management of uranium mine and mill wastes. Such wastes also contain non-radiological contaminants (heavy metals, acids and neutralising agents) which give rise to potential long-term health and environmental hazards and short-term hazards to the aquatic ecosystem, e.g. as a result of release of waste water. This study seeks to identify non-radiological contaminants (elements) transferred to waste water at the Ranger uranium mine/mill complex at Jabiru, which are likely to hazardous to the aquatic environment.The two principal sources of contaminants are: (i) ore and waste rock mobilised from mining; and (ii) process reagents used in the milling and mineral extraction process. These substances may or may not already be present in the natural environment but may lead to deleterious effects on the aquatic environment if increased above threshold levels.Rhenium, derived from the ore body, was found to be significantly enriched in waste water from Ranger, indicating its suitability as an indicator element for water originating from the mining and milling process, but only uranium, likewise derived from the ore, and magnesium, manganese and sulfur (as sulfate) from the milling process were found to be significant environmental contaminants.

The recovery of a concentrate of tin and tungsten from ore mined at Van Roois Vley

International Nuclear Information System (INIS)

Guest, R.N.

1985-01-01

Concentration tests using gravity separation, flotation, and magnetic separation showed that it is possible for the high-grade ore mined at Van Roois Vley to be upgraded to a concentrate containing 61 per cent Sn-Wo 3 at a recovery of about 80 per cent, and for the low-grade ore to be upgraded to 53 per cent Sn-WO 3 at the same recovery. However, it is suggested that, under normal mining conditions and with large-scale mining equipment, less fines would be produced and this should lead to an increase in grade and recovery. Mineralogical examinations showed that intermediate fractions produced by tabling contained very few locked particles, and that the grade of the final concentrate on a full-scale plant would probably be higher than that obtained with laboratory equipment. Molybdenite could be a valuable byproduct, but flotation tests of gravity concentrates for selective recovery of the mineral gave variable results. Flotation tests for the removal of fluorspar from the final concentrate were unsuccessful

Recovery of uranium mineral from Liaoning Fengcheng ludwigite ore by gravity concentration

International Nuclear Information System (INIS)

Zhang Tao; Liang Haijun; Xue Xiangxin

2009-01-01

A laboratory research was carried out to recover uranium mineral from Liaoning Fengcheng ludwigite ore. Gravity concentration methods including hydroclone, spiral chute and shaking table were applied in this study. The results show that a concentrate with uranium grade of 0.216% and recovery of 44.24% could be produced from the feed of uranium content 0.006 3%. This research is helpful to comprehensive utilization of the mineral resources. Increasing further uranium mineral liberation degree is the key to improve separation effects. (authors)

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.

Direct Flotation of Niobium Oxide Minerals from Carbonatite Niobium Ores

Science.gov (United States)

Ni, Xiao

Currently the recovery of niobium oxide minerals from carbonatite niobium ores relies on the use of non-selective cationic collectors. This leads to complicated process flowsheets involving multiple desliming and multiple reverse flotation stages, and low niobium recovery. In this research, anionic collectors that are capable of strong chemisorption on the niobium minerals were studied with the objective of directly floating the niobium oxide minerals from the carbonatite ores. In the flotation of both high purity minerals and Niobec ores, it was shown that the combination of hydroxamic acid and sodium metaphosphate was an effective reagent scheme for the direct flotation of niobium oxide from its ores. Batch flotation on the Niobec Mill Feed showed that over 95% of niobium oxide was recovered into a rougher concentrate that was less than 47% of the original feed mass. Preliminary cleaning tests showed that the reagent scheme could also be used to upgrade the rougher concentrate, although the depression of iron oxide minerals required further study. X-ray photoelectron spectroscopic (XPS) measurement results confirm that OHA (octyl hydroxamic acid) could chemisorb on pyrochlore surface while only physically adsorb on calcite, judging by the chemical shifts of electron binding energies in the elements in both OHA and the mineral surfaces. When hydroxamic acid was adsorbed on calcite surface, the binding energies of the N 1s electrons, at 400.3 eV, did not shift. However, after adsorption on pyrochlore, the N 1s binding energy peak split into two peaks, one at a binding energy of around 399 eV, representing chemically adsorbed OHA, the other at between 400 and 401 eV. The experimental data suggested a strong chemisorption of the OHA on pyrochlore surface in the form of a vertical head-on orientation of the OHA molecules so that the pyrochlore was strongly hydrophobized even at low OHA concentrations, followed by possibly randomly oriented physisorbed OHA molecules

Airborne particulate concentrations and fluxes at an active uranium mill tailings site

International Nuclear Information System (INIS)

Sehmel, G.A.

1978-01-01

Direct measurements of airborne particulate concentrations and fluxes of transported mill tailing materials were measured at an active mill tailings site. Experimental measurement equipment consisted of meteorological instrumentation to automatically activate total particulate air samplers as a function of wind speed increments and direction, as well as particle cascade impactors to measure airborne respirable concentrations as a function of particle size. In addition, an inertial impaction device measured nonrespirable fluxes of airborne particles. Caclulated results are presented in terms of the airborne solid concentration in g/m 3 , the horizontal airborne mass flux in g/(m 2 -day) for total collected nonrespirable particles and the radionuclide concentrations in dpm/g as a function of particle diameter for respirable and nonrespirable particles

THE TRANSITIONAL CHANGE ON THE IMPLEMENTATION OF ISO 14001:2015 IN COPPER ORE MILL – CASE STUDY

Directory of Open Access Journals (Sweden)

Arif Susanto

2017-09-01

Full Text Available The transition process of implementation standard for environmental management system (EMS ISO 14001 :2015 lasts for three years, requiring every organization to adopt the latest version by September 2018. The objectives of this research is to describe and analyze the stages done by copper ore mill. This research used concept analysis method, which focused and could be basically defined to examine the basic elements of widely used concept to clarify ISO 14001 :2015 standards characteristics and relations. The result of this research provided a conceptual framework based on the standard of ISO 14001:2015 – EMS : Requirements with Guidance for Use, where this framework consists to steps to design the transition change from EMS ISO 14001 :2004 to its 2015 new version. The description of every step is expected to give understanding and model for organizations that must conduct transition and for the ones that will start implementing the EMS.

Airborne effluent control at uranium mills

International Nuclear Information System (INIS)

Sears, M.B.

1976-01-01

The Oak Ridge National Laboratory has made an engineering cost--environmental benefit study of radioactive waste treatment systems for decreasing the amount of radioactive materials released from uranium ore processing mills. This paper summarizes the results of the study which pertain to the control and/or abatement of airborne radioactive materials from the mill processes. The tailings area is not included. Present practices in the uranium milling industry, with particular emphasis on effluent control and waste management, have been surveyed. A questionnaire was distributed to each active mill in the United States. Replies were received from about 75 percent of the mill operators. Visits were made to six operating uranium mills that were selected because they represented the different processes in use today and the newest, most modern in mill designs. Discussions were held with members of the Region IV Office of NRC and the Grand Junction Office of ERDA. Nuclear Science Abstracts, as well as other sources, were searched for literature pertinent to uranium mill processes, effluent control, and waste management

Thirty years of uranium ore processing in Spain

International Nuclear Information System (INIS)

Josa, J.M.

1982-01-01

Spanish background in the uranium ore processing includes ores from pegmatitic type deposits, vein deposits, sandstone, enrichments in metamorphic rocks, radioactive coals and non-conventional sources of uranium, such as wet phosphoric acid or copper liquors. Some tests have also done in order to recover uranium from very low grade paleozoic quartzites. We have also been involved in by-products recovery (copper) from uranium ores. The technologies that have been used are: physical concentration, combustion and roasting, conventional alkaline or acid methods, pressure, heap and bacteria leaching. Special attention was paid to recover uranium from the pregnant liquors and to develop suited equipment for it; solvent extraction and continuous ion exchange equipment was carefully studied. We have been involved in commercial size (500-3000 t/d) mills, but we have also developed transportable and reussable modular plants specially designed and suited to recover uranium from small and isolated deposits. In both cases the reduction of the environmental impact was taken in account. Spanish experience also includes nuclear purification aspects in order to get uranium nuclear compounds (ADU, UO 2 , UF 4 and UF 6 ). Wet (nitric-TBP) and dry (Fluid-bed) methods have been used. The best of these 30 years of experience in studies and in industrial practice, together with our new developments towards the future, could become in a good contribution for the medium size countries which are going to develop its own uranium industry. The way for these countries could be easier if they know what is valuable and what must be avoid in the uranium ore processing development. In this aim the whole paper was thought and written. (author)

Mortality patterns among a retrospective cohort of uranium mill workers

International Nuclear Information System (INIS)

Waxweiler, R.J.; Archer, V.E.; Roscoe, R.J.; Watanabe, A.; Thun, M.J.

1983-01-01

The long-term health effects associated with the milling of uranium ore are of interest particularly because of exposures to uranium and thorium-230. Excess risks of pulmonary and lymphatic malignancies have been suggested by previous epdiemiologic studies of persons milling or smelting uranium ores, and nephrotoxic effects of uranium have been reported in both man and animals. To test these three previously reported associations and to assess all cause-specific mortality patterns among uranium mill workers, we carried out a retrospective cohort study of 2002 uranium millers employed in any of seven mills at least one year before 1972. Ninety-eight percent (98%) followup of the cohort through 1977 resulted in 533 deaths observed versus 605 expected from US White male mortality rates. Mortality from most causes was lower than expected. Significant excess risks were found only for nonmalignant respiratory disease and miscellaneous accidents but not for any of the three diseases of a priori interest. However, nonsignificant excesses were found for lymphatic malignancies after 20 years latency and for death due to chronic nephritis among short-term workers

Continuous tests of Phosphoric Acid - dihydrate process - from phosphatic concentrate of Itataia-CE ore

International Nuclear Information System (INIS)

Santos Benedetto, J. dos.

1984-01-01

A consolidation of principal studies and continuous tests done with phosphatic concentrated of Itataia ore intending phosphoric acid production by humid-route dihydrate way process is presented. The production of phosphoric acid is applied in uranium extraction process by solvents. (author) [pt

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.

Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

International Nuclear Information System (INIS)

Song Huanbi; Hu Yezang

1997-01-01

The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

Replacement of lumpy chrome ore by agglomerated ore concentrates and lowering of specific power consumption and improvement of Cr-yield by means of improved slag composition in the production of H.C. Ferrochrome

International Nuclear Information System (INIS)

Retelsdorf, H.J.; Fichte, R.; Breuer, F.; Zimmermann, H.

1982-06-01

Work on this project is finished, but further work on the use of Cr-ore briquettes seems necessary. It was the aim of the project to develop improved slag compositions for the FeCr 4-6% C-process resulting in higher Cr-yield and lower specific power consumption. Furthermore, replacement of lumpy ore in the charge by agglomerated Cr-ore-fines or concentrates in the form of pellets and briquettes was to be tested. Experimentals were performed in a 70 kW and a 300 kW arc furnace. Two different slag compositions were tested. The high-MgO slag type proved suitable. The specific power consumption and the Cr-yield depend to a large extent on the type of Cr-ore and on the agglomeration process. Cr-ore pellets can be used up to 65% in the ore charge but briquettes can be used only up to 25% to replace lumpy ores without causing higher Cr-losses in the slag. (orig.) [de

Delineation of the extent of milling-related contamination in a naturally contaminated aquifer system

International Nuclear Information System (INIS)

Downs, William F.; Storms, Erik F.

1992-01-01

Uranium mill tailings from the Susquehanna-Western mill near Falls City, Texas, were pumped to tailings ponds located in abandoned open pit uranium mines. The ores from these mines were oxidized. Uranium and the associated hazardous constituents were present in these ores as relatively soluble secondary minerals. Because the tailings piles are located on the outcrops of the units designated as the uppermost aquifer, there is no upgradient aquifer from which to establish 'background' water quality. The widespread mineralization in the area naturally imposes a large variability in water quality in these units. It was necessary to demonstrate to State and Federal regulators that selected downgradient wells were beyond the influence of milling operations, and to develop a series of 'indicator parameters' that could be used to differentiate milling contaminated groundwater from that native to the aquifer. (author)

Radiation protection of workers in uranium mining, ore processing and fuel fabrication in India

International Nuclear Information System (INIS)

Khan, A. H.; Jha, G.; Jha, S.; Srivastava, G. K.; Sadasivan, S.; Raj, Venkat

2002-01-01

Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. This concentrate is further processed at the Nuclear Fuel Complex at Hyderabad, in southern India, to produce fuel for use in nuclear power plants. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at each site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body are based on the international standards suggested by the ICRP and the IAEA. In the uranium mines external gamma radiation, radon and airborne activity due to radioactive dust is monitored. Similarly, in the uranium mill and the fuel fabrication plant gamma radiation and airborne radioactivity due to long-lived α -emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the personal monitoring and area monitoring data. It has been observed that the total radiation dose to workers has been well below 20 mSv.y 1 at all stages of operations. Adequate ventilation is provided during mining, ore processing and fuel fabrication operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper

Radiation protection of workers in uranium mining, ore processing and fuel fabrication in India

International Nuclear Information System (INIS)

Khan, A.H.; Jha, G.; Jha, S.; Srivastava, G.K.; Sadasivan, S.; Venkat Raj, V.

2002-01-01

Full text: Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. This concentrate is further processed at the Nuclear Fuel Complex at Hyderabad, in southern India, to produce fuel for use in nuclear power plants. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at each site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body are based on the international standards suggested by the ICRP and the IAEA. In the uranium mines external gamma radiation, radon and airborne activity due to radioactive dust is monitored. Similarly, in the uranium mill and the fuel fabrication plant gamma radiation and airborne radioactivity due to long-lived a- emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the personal monitoring and area monitoring data. It has been observed that the total radiation dose to workers has been well below 20 mSvy -1 at all stages of operations. Adequate ventilation is provided during mining, ore processing and fuel fabrication operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper

Rock Characteristics and Ball Mill Energy Requirements at ...

African Journals Online (AJOL)

These changes can have great impact on milling operations. ... Goldfields Ghana Limited, Tarkwa Gold Mine (TGM), processes ores which occur in ... The parameters examined had deviated from the design; Work Index (WI) for example was ...

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.)

Draft environmental statement related to the Western Nuclear, Inc. Split Rock Mill (Fremont County, Wyoming)

International Nuclear Information System (INIS)

1978-11-01

The proposed action is the renewal of Source Material License SUA-56 (with amendments) issued to Western Nuclear, Inc. (WNI), for the operation of the Split Rock uranium mill near Jeffrey City and the Green Mountain ion-exchange facility, both in Fremont County, Wyoming. The license also permits possession of material from past operations at four ancillary facilities in the Gas Hills mining area--the Bullrush, Day-Loma, Frazier-Lamac, and Rox sites (Docket No. 40-1162). The Split Rock mill is an acid-leach, ion-exchange and solvent-extraction uranium-ore processing mill with a design capacity of 1540 MT (1700 tons) of ore per day. WNI has proposed by license amendment request to increase the storage capacity of the tailings ponds in order to permit the continuation of present production rates of U 3 O 8 through 1996 using lower-grade ores. Conditions for the protection of the environment include reclamation, tailings, stabilization, archeological survey, monitoring, etc

Standard practices for sampling uranium-Ore concentrate

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 These practices are intended to provide the nuclear industry with procedures for obtaining representative bulk samples from uranium-ore concentrates (UOC) (see Specification C967). 1.2 These practices also provide for obtaining a series of representative secondary samples from the original bulk sample for the determination of moisture and other test purposes, and for the preparation of pulverized analytical samples (see Test Methods C1022). 1.3 These practices consist of a number of alternative procedures for sampling and sample preparation which have been shown to be satisfactory through long experience in the nuclear industry. These procedures are described in the following order. Stage Procedure Section Primary Sampling One-stage falling stream 4 Two-stage falling stream 5 Auger 6 Secondary Sampling Straight-path (reciprocating) 7 Rotating (Vezin) 8, 9 Sample Preparation 10 Concurrent-drying 11-13 Natural moisture 14-16 Calcination 17, 18 Sample Packaging 19 Wax s...

Jaduguda uranium mill : rich experiences for future challenges

International Nuclear Information System (INIS)

Beri, K.K.

1991-01-01

India's only uranium milling plant at Jaduguda was commissioned in 1967-68 utilising low grade uranium ore. The flowsheet of the mill and controlling parameters were based on studies done on laboratory and pilot plant scale tests at the Bhabha Atomic Research Centre, Bombay. The mill has worked upto expectation except in few areas where modifications had to be done for smooth production. Apart from this improvements in operating practices have been done based on experience gained in operating the mill, incorporating the recent technological advances. In the recent past, the mill was expanded to increase the installed capacity by 40% and was commissioned in October 1987. The expanded mill has given the desired capacity and is working smoothly. The present paper deals with the experience gained in running the plant for the last 20 years and changes incorporated (author). 4 figs

Influence of acid/ore relation in the uranium-silicate ore treatment

International Nuclear Information System (INIS)

Antaki, C.; Cipriani, M.; Bruno, J.B.

1985-01-01

The estimation of acid addition effect (Kg of H 2 SO 4 /t of ore) in uranium extraction from an uranium-silicate ore, with a view to the control of silica concentration in leach under 0,6 g/l is presented. The analysis was effected based on bench-scale tests, with different quantities of sulfuric acid addition. (Author) [pt

Predicting arsenic concentrations in porewaters of buried uranium mill tailings

Energy Technology Data Exchange (ETDEWEB)

Langmuir, D.; Mahoney, J.; MacDonald, A.; Rowson, J.

1999-10-01

The proposed JEB Tailings Management Facility (TMF) to be emplaced below the groundwater table in northern Saskatchewan, Canada, will contain uranium mill tailings from McClean Lake, Midwest and Cigar Lake ore bodies, which are high in arsenic (up to 10%) and nickel (up to 5%). A serious concern is the possibility that high arsenic and nickel concentrations may be released from the buried tailings, contaminating adjacent groundwaters and a nearby lake. Laboratory tests and geochemical modeling were performed to examine ways to reduce the arsenic and nickel concentrations in TMF porewaters so as to minimize such contamination from tailings buried for 50 years and longer. The tests were designed to mimic conditions in the mill neutralization circuit (3 hr tests at 25 C), and in the TMF after burial (5--49 day aging tests). The aging tests were run at 50, 25 and 4 C (the temperature in the TMF). In order to optimize the removal of arsenic by adsorption and precipitation, ferric sulfate was added to tailings raffinates having Fe/As ratios of less than 3--5. The acid raffinates were then neutralized by addition of slaked lime to nominal pH values of 7, 8, or 9. Analysis and modeling of the test results showed that with slaked lime addition to acid tailings raffinates, relatively amorphous scorodite (ferric arsenate) precipitates near pH 1, and is the dominant form of arsenate in slake limed tailings solids except those high in Ni and As and low in Fe, in which cabrerite-annabergite (Ni, Mg, Fe(II) arsenate) may also precipitate near pH 5--6. In addition to the arsenate precipitates, smaller amounts of arsenate are also adsorbed onto tailings solids. The aging tests showed that after burial of the tailings, arsenic concentrations may increase with time from the breakdown of the arsenate phases (chiefly scorodite). However, the tests indicate that the rate of change decreases and approaches zero after 72 hrs at 25 C, and may equal zero at all times in the TMF at 4 C

Uranium mill tailings remedial action technology

International Nuclear Information System (INIS)

Hartley, J.N.; Gee, G.W.

1984-01-01

The uranium milling process involves the hydrometallurgical extraction of uranium from ores and the resultant generation of large quantities of waste referred to as tailings. Uranium mill tailings have been identified as requiring remediation because they contain residual radioactive material that is not removed in the milling process. Potential radiation exposure can result from direct contact with the tailings, from radon gas emitted by the tailings, and from radioactive contamination of groundwater. As a result, the technology developed under the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) and the US Nuclear Regulatory Commission (NRC) Uranium Recovery Program have focused on radon control, groundwater contamination and the long-term protection of the containment system. This paper briefly summarizes the UMTRAP and NRC remedial action technology development. 33 references, 9 figures, 5 tables

Final environmental statement related to the Western Nuclear, Inc., Split Rock Uranium Mill (Fremont County, Wyoming)

International Nuclear Information System (INIS)

1980-02-01

The proposed action is the renewal of Source Material License SUA-56 (with amendments) issued to Western Nuclear, Inc. (WNI), for the operation of the Split Rock Uranium Mill near Jeffrey City and the Green Mountain Ion-Exchange Facility, both in Fremont County, Wyoming. The license also permits possession of material from past operations at four ancillary facilities in the Gas Hills mining area - the Bullrush, Day-Loma, Frazier-Lamac, and Rox sites (Docket No. 40-1162). However, although heap leaching operations were previously authorized at Frazier-Lamac, there has never been any processing of material at this site. The Split Rock mill is an acid-leach, ion-exchange and solvent-extraction uranium-ore processing mill with a design capacity of 1540 MT (1700 tons) of ore per day. WNI has proposed by license amendment request to increase the storage capacity of the tailings ponds in order to permit the continuation of present production rates of U 3 O 8 through 1996 using lower-grade ores

Assessment of environmental aspects of uranium mining and milling. Final report, 12 February--7 July 1976

International Nuclear Information System (INIS)

Reed, A.K.; Meeks, H.C.; Pomeroy, S.E.; Hale, V.Q.

1976-12-01

This research program was initiated with the basic objective of making a preliminary assessment of the potential environmental impacts associated with the mining and milling of domestic uranium ores. All forms of pollution except radiation were considered. The program included a review of the characteristics and locations of domestic uranium ore reserves and a review of the conventional methods for mining and milling these ores. Potential environmental impacts associated with the entire cycle from exploration and mining to recovery and production of yellowcake are identified and discussed. Land reclamation aspects are also discussed. The methods currently used for production of yellowcake were divided into four categories - open pit mining-acid leach process, underground mining-acid leach process, underground mining-alkaline leach process, and in-situ mining. These are discussed from the standpoint of typical active mills which were visited during the program. Flowsheets showing specific environmental impacts for each category are provided

O-Ring sealing arrangements for ultra-high vacuum systems

Science.gov (United States)

Kim, Chang-Kyo; Flaherty, Robert

1981-01-01

An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

Final environmental statement related to the Atlas Minerals Division, Atlas Corporation, Atlas Uranium Mill (Grand County, Utah)

International Nuclear Information System (INIS)

1979-01-01

The proposed action is the continuation of Source Material License SUA-917 issued to Atlas Corporation for the operation of the Atlas Uranium Mill in Grand County, Utah, near Moab (Docket No. 40-3453). The present mill was designed for an 1100 MT (1200 ton) per day processing rate with 0.25% uranium ore feed. The actual ore processing rate may vary up to 1450 MT (1600 ton) per day if lower grade ores are processed, but the annual production rate of 836 MT (921 tons) U 3 O 8 will not be exceeded. Possible environmental impacts and adverse effects are identified. Conditions for the protection of the environment are set forth before the license can be renewed

Radiation protection in uranium mining and milling industry

International Nuclear Information System (INIS)

Raghavayya, M.

2005-01-01

The first phase of the Nuclear Fuel Cycle is exploration for uranium and the next is mining and milling of uranium ore. This phase is mostly characterised by low levels of radioactivity and radiation exposure of the workers involved. Yet it is a paradoxical truth that incidence of cancer among the work force, especially miners, due to occupational radiation exposure (from radon and decay products) has been proved only in uranium mines in the entire Nuclear Fuel Cycle. Of course such incidence occurred before the detrimental effect of radiation exposure was realised and understood. Therefore it is important to familiarise oneself with the radiation hazards prevalent in the uranium mining and milling facilities so as to take appropriate remedial measures for the protection of not only the workers but also the public at large. There are both open cast and underground uranium mines around the world. Radiation hazards are considerably less significant in open cast mines than in underground mines unless the ore grade is very high. By default therefore the discussion which ensues relates mainly to radiation hazards in underground uranium mines and associated milling operations. The discussion gives a brief outline of typical uranium mine and mining and milling operations. This is followed by a description of the radiation hazards therein and protection measures that are to be taken to minimise radiation exposure. (author)

Uranium ore waste management of the CIPC (Mining Industrial Complex of Pocos de Caldas Plateau, Minas Gerais State, Brazil)

International Nuclear Information System (INIS)

Wiikmann, Luiz Oide; Figueiredo, Nestor; Taddei, Jose Fernando Aguiar Carrazedo; Valente, Sergio Mozart Coutinho; Chilelli Junior, Vicente; Souza, Vicente Paulo de

1995-01-01

Since 1982, the facilities in CIPC has been producing a uranium concentrate under ammonium diuranate form, from uranium ore. The CIPC,s Waste Management System is responsible for monitoring and controlling the mining and milling effluents, in accordance with norms established by government regulatory agencies. Here we are concerned with this system's efficiency, costs and, with necessary procedures for waste rock piles'stabilization in physical, chemical and biological aspects with aim of environmentally restoring these areas. (author). 2 refs., 6 figs., 5 tabs

Problems of restoration disturbed areas in the conduction uranium mining and milling

International Nuclear Information System (INIS)

Isakin, V.S.; Konev, G.V.

1996-01-01

State-holding company Tselinnyj Mining Chemical Company (TMCC) is headed enterprise for mining and milling uranium ore in North Kazakstan was at five main areas (ore's direction). Mining was a traditional forms. Currently, the main problems of restoration disturbed areas in the conditions of uranium mining and milling are: economic insolvency of conversion enterprises, with has not own means for exude restoration and decontamination. TMCC has urgent need of State Programme, that provides finance of restoration work. Problem of radioactive contamination shall be insolvable, if company will go bankrupt. This programme should contained an item for elaboration regulative, normative and methodological documents if low level radioactive waste in Kazakstan. Program must take into consideration progressive domestic and foreign experience

Distribution of uranium-238 in environmental samples from a residential area impacted by mining and milling activities

International Nuclear Information System (INIS)

McConnell, M.A.; Ramanujam, V.M.S.; Alcock, N.W.; Gabehart, G.J.; Au, W.W.

1998-01-01

The northern region of Karnes County, Texas, USA, has been the site of extensive mining/milling of uranium for over 30 years. A previous study in their laboratory indicates that residents living near these facilities have increased chromosomal aberrations and a reduced DNA repair capacity. In this study, the long-lived radionuclides uranium-238 ( 238 U) and thorium-232 ( 232 Th) were measured in order to evaluate the extent of contamination from mining/milling facilities. 232 Th was quantified simultaneously and served as a reference. Soil samples were collected from the yards of previously studied households and adjacent areas near former mining and mining/milling sites at the surface and 30 cm subsurface. Additionally, samples from drinking water wells were collected from selected households. Sites located over 14 km from the study area with no known history of mining/milling served as the control. In the control area, 238 U concentrations in soil were consistent between surface (0.13--0.26 mg/kg) and subsurface samples. Near mining/milling sites, 238 U in surface soil was found to be consistently and statistically higher than corresponding subsurface samples. Near mining-only areas, 238 U in surface soil, however, was not significantly increased over subsurface soil. As expected, 238 U was much higher overall in the mining/milling and mining-only areas compared to the control sites. No trends were detected in the distribution of 232 Th. The concentration of 238 U was up to six times higher in a drinking water well near a former mining/milling operation, indicating possible leaching into the groundwater, while 232 Th concentrations were low and uniform. Furthermore, lead isotope ratio analysis indicates contamination from the interstate shipping of ore by rail to and from a mining/milling facility. These data indicate contamination of the environment by the mining/milling activities in a residential area

Progress report on a study of contamination of the human food chain by uranium mill tailings piles

International Nuclear Information System (INIS)

Holtzman, R.B.; Urnezis, P.W.; Padova, A.; Bobula, C.M. III.

1978-01-01

A study is in progress to estimate the contamination of the human food chain by uranium, 230 Th, 226 Ra, 210 Pb, and 210 Po originating from tailing piles associated with uranium ore processing mills. Rabbits, cattle, vegetables, and grass were collected on or near two uranium mill sites. For controls, similar samples were obtained from areas 20 km or more from the mining and milling operations. For the on-site rabbits the mean 226 Ra concentrations in muscle, lung, and kidney of 5.5, 14, and 15 pCi/kg wet, respectively, were substantially higher than those in the respective tissues of control animals (0.4, 1.5, and 0.2 pCi/kg). The levels in liver did not differ significantly between the groups. The concentrations in bone (femur and vertebra) were about 9000 and 350 pCi/kg ash for the on- and off-site animals, respectively. The levels of 210 Pb and 210 Po did not differ significantly for a given tissue between the two groups. For cattle the existing data indicate that the concentrations of radionuclides do not differ greatly between those grazed near the pile and the controls, except that the 210 Pb concentration in the liver of an exposed animal is greater than that of the control. Vegetables from a residential area on a mill site contained substantially greater concentrations of 226 Ra and 210 Pb than those reported for standard New York City diets

The impact of new technology on the economics of uranium production from low-grade ores

International Nuclear Information System (INIS)

Simonsen, H.A.; Boydell, D.W.; James, H.E.

1981-01-01

The subject is discussed under the following headings: influence of a depressed market on uranium supply from low-grade ores; potential areas for a reduction in uranium ore processing costs; in-situ leaching (solution mining; heap leaching; resin-in-pulp; solvent-in-pulp; belt filtration; continuous ion exchange; solvent extraction); preconcentration (upgrading of coarse rock; upgrading in the mill; wet high-intensity magnetic separation; flotation); summary and conclusions. (U.K.)

Characterization and classification of uranium ore concentrates (yellow cakes) using infrared spectrometry

Energy Technology Data Exchange (ETDEWEB)

Varga, Z.; Oeztuerk, B.; Mayer, K.; Wallenius, M.; Apostolidis, C. [Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; Meppen, M. [Carl Friedrich von Weizsaecker-Zentrum fuer Naturwissenschaft und Friedensforschung, Hamburg (Germany)

2011-07-01

In this work the applicability of Fourier-transform infrared spectrometry (FTIR) for nuclear forensic studies of uranium ore concentrates (UOC) are investigated. The technique was used for the identification of the type of uranium compound and various process-related impurities, which can give information on the production method of the material. The measured spectra were evaluated also by statistical means, using the soft independent modelling of class analogy (SIMCA) technique to reveal less apparent similarities between the measured UOC samples.

Air Pollution Modelling to Predict Maximum Ground Level Concentration for Dust from a Palm Oil Mill Stack

Directory of Open Access Journals (Sweden)

Regina A. A.

2010-12-01

Full Text Available The study is to model emission from a stack to estimate ground level concentration from a palm oil mill. The case study is a mill located in Kuala Langat, Selangor. Emission source is from boilers stacks. The exercise determines the estimate the ground level concentrations for dust to the surrounding areas through the utilization of modelling software. The surround area is relatively flat, an industrial area surrounded by factories and with palm oil plantations in the outskirts. The model utilized in the study was to gauge the worst-case scenario. Ambient air concentrations were garnered calculate the increase to localized conditions. Keywords: emission, modelling, palm oil mill, particulate, POME

Training manual for uranium mill workers on health protection from uranium

International Nuclear Information System (INIS)

McElroy, N.; Brodsky, A.

1986-01-01

This report provides information for uranium mill workers to help them understand the radiation safety aspects of working with uranium as it is processed from ore to yellowcake at the mills. The report is designed to supplement the radiation safety training provided by uranium mills to their workers. It is written in an easily readable style so that new employees with no previous experience working with uranium or radiation can obtain a basic understanding of the nature of radiation and the particular safety requirements of working with uranium. The report should be helpful to mill operators by providing training material to support their radiation safety training programs

Measurements of CaF2 concentration in fluorite ore using thermoluminescence techniques

International Nuclear Information System (INIS)

Lembo, L.; Maestri, G.; Pimpinella, M.; Benzi, V.; Muntoni, C.

1990-01-01

Fluorite powder is produced by means of a flotation process on crude ore extracted by the mines. A full automation of the flotation plant would reduce the operating cost and improve the quality and recovery of fluorite production. However, taking into account that the efficiency of a flotation cycle is directly dependent on the CaF 2 content in the concentrate and tail products, this automation requires a quasi-real-time quantitative analysis of CaF 2 concentration in the floated pulp. The feasibility was studied of using a thermoluminescence technique as an on-line analysis method to measure the CaF 2 concentration during the flotation cycle. A first set of experimental conditions to determine CaF 2 content in acid-grade fluorspar has been already developed and the preliminary results so far obtained are presented. (author)

Testing of X-ray radiometric enrichnment of polymetallic ores

International Nuclear Information System (INIS)

Eliseev, N.I.; Panova, N.I.; Kirbitova, N.V.; Shramm, E.O.; Efremov, Yu.G.

1987-01-01

Testing of X-ray radiometric method of sorting of polymetallic ores using the developed X-ray radiometric device was conducted. It was shown that introduction of preliminary concentration at the factory made the method of fragment separation to be the perspective one, enabling to elevate the factory production with respect to commercial ore and reduce the cost of ore processing. In the case of preliminary concentration, conducted at the mine, it is advisable to perform ore sorting in the flow formed to monolayer

Development of uranium milling and conversion

International Nuclear Information System (INIS)

Takada, Shingo; Hirono, Shuichiro.

1983-11-01

The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellowcake as an intermediate product, have been carried out for over ten years with a small pilot plant (50 t-ore/day). In the past several years, a process for converting uranium tetrafluoride into hexafluoride has been developed successfully. To develop the process further, the construction of an integrated milling and conversion pilot plant (200 t-U/year) started in 1979 and was completed in 1981. This new plant has two systems of solvent extraction using tri-noctylamine: one of the systems treats the pregnant solution (uranyl sulphate) by heap-leaching followed by ion exchange, and the other treats the uranyl sulphate solution by dissolving imported yellowcake. The uranium loading solvents from the two systems are stripped with hydrochloric acid solution to obtain the concentrated uranium solution containing 100 g-U/1. Uranyl sulphate solution from the stripping circuit is reduced to a uranous sulphate solution by the electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In the following hydrofluorination step, uranium tetrafluoride, UF 4 .1-1.2H 2 O (particle size: 50-100μ), is produced continuously as the precipitate in an improved reaction vessel, and this makes it possible to simplify the procedures of liquid-solid separation, drying and granulation. The uranium tetrafluoride is dehydrated by heating to 350 0 C in an inert gas flow. The complete conversion from UF 4 into UF 6 is achieved by a fluidized-bed reactor and a high value of utilization efficiency of fluorine, over 99.9 percent, is attained at about 400 0 C. (author)

Environmental restoration plans and activities in the zones of uranium ore extraction and milling in Romania: 1995-1996 progress report

International Nuclear Information System (INIS)

Bejenaru, C.; Ionescu, I.; Georgescu, D.

1997-01-01

The objective of this paper is to present the ecological impact on environment as a consequence of more than 30 years of activity in the field of uranium exploration, mining and ore processing in Romania and a brief description of the measures taken for limiting the effects of contamination on the affected zones including the proposed restructuring and rehabilitation programmes. The Autonomous Regie for Rare Metals (RAMR), the coordinator of the activities in the uranium field is responsible to implement the provisions of the IAEA Technical Cooperation Project on Environmental Restoration in Central and Eastern Europe joined by Romania in 1993. The characterization of radioactively contaminated areas is dealt with broadly under two categories, one pertaining to sites where the mining and milling activities have already ceased and the other where the units are still operational but are going to be closed down in the near future and will be placed under surveillance. Generally speaking, the activity in the uranium field is developed by observing the national Norms of Nuclear Safety for the Activity of Geological Investigation, Mining and Milling of Nuclear Raw Material. This report includes an evaluation of the necessary investments for the first stage of the programme dealing with the environmental restoration and the necessary research activities. This will be followed by studies for closing down and surveillance of the mines with special problems taking into account their depth and complex hydrology

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)

Biogeochemical aspects of uranium mineralization, mining, milling, and remediation

Science.gov (United States)

Campbell, Kate M.; Gallegos, Tanya J.; Landa, Edward R.

2015-01-01

Natural uranium (U) occurs as a mixture of three radioactive isotopes: 238U, 235U, and 234U. Only 235U is fissionable and makes up about 0.7% of natural U, while 238U is overwhelmingly the most abundant at greater than 99% of the total mass of U. Prior to the 1940s, U was predominantly used as a coloring agent, and U-bearing ores were mined mainly for their radium (Ra) and/or vanadium (V) content; the bulk of the U was discarded with the tailings (Finch et al., 1972). Once nuclear fission was discovered, the economic importance of U increased greatly. The mining and milling of U-bearing ores is the first step in the nuclear fuel cycle, and the contact of residual waste with natural water is a potential source of contamination of U and associated elements to the environment. Uranium is mined by three basic methods: surface (open pit), underground, and solution mining (in situ leaching or in situ recovery), depending on the deposit grade, size, location, geology and economic considerations (Abdelouas, 2006). Solid wastes at U mill tailings (UMT) sites can include both standard tailings (i.e., leached ore rock residues) and solids generated on site by waste treatment processes. The latter can include sludge or “mud” from neutralization of acidic mine/mill effluents, containing Fe and a range of coprecipitated constituents, or barium sulfate precipitates that selectively remove Ra (e.g., Carvalho et al., 2007). In this chapter, we review the hydrometallurgical processes by which U is extracted from ore, the biogeochemical processes that can affect the fate and transport of U and associated elements in the environment, and possible remediation strategies for site closure and aquifer restoration.This paper represents the fourth in a series of review papers from the U.S. Geological Survey (USGS) on geochemical aspects of UMT management that span more than three decades. The first paper (Landa, 1980) in this series is a primer on the nature of tailings and radionuclide

Nuclear-fuel-cycle education: Module 2. Exploration, reserve estimation, mining, milling, conversion, and properties of uranium

International Nuclear Information System (INIS)

Brookins, D.G.

1981-12-01

In this module geological and geochemical data pertinent to locating, mining, and milling of uranium are examined. Chapters are devoted to: uranium source characteristics; uranium ore exploration methods; uranium reserve estimation for sandstone deposits; mining; milling; conversion processes for uranium; and properties of uranium, thorium, plutonium and their oxides and carbides

Correlation between gamma radiation levels and soil radium concentrations at the Edgemont uranium mill site

International Nuclear Information System (INIS)

Wallace, R.G.; Reed, R.P.; Polehn, J.L.; Wilson, G.T.

1985-01-01

The Tennessee Valley Authority's uranium mill in Edgemont, South Dakota, is being decommissioned. Approximately 4 million tons of contaminated tailings, building equipment, and contaminated soil and debris on the mill site will be removed to the disposal site located approximately 3 kilometers to the southeast. To minimize recontamination of cleaned areas, tailings removal will progress from the northwest corner to the southeast corner of the mill site. As specific areas are cleaned, surveys will be conducted to determine if the concentrations of radium-226 in soil are within the limits outlined in 40 CFR, Part 192. Conformance with the criteria will be demonstrated by a gamma survey of the area employing the differential, or delta-measurement, technique. This technique involves fitting the detector with a base and a receptacle for a removable high-density filter. By making measurements with and without the filter in place, a gamma radiation level proportional to the radium-226 concentration in soil can be determined. This paper describes the results obtained in the development of the correlation between the gamma survey measurements and the soil radium concentrations

Correlation between gamma radiation levels and soil radium concentrations at the Edgemont uranium mill site

International Nuclear Information System (INIS)

Wallace, R.G.; Reed, R.P.; Polehn, J.L.; Wilson, G.T.

1986-01-01

The Tennessee Valley Authority's uranium mill in Edgemont, South Dakota is being decommissioned. Approximately 4 million tons of contaminated tailings, building equipment, and contaminated soil and debris on the mill site will be removed to the disposal site located approximately 3 kilometers to the southeast. To minimize recontamination of cleaned areas, tailings removal will progress from the northwest corner to the southeast corner of the mill site. As specific areas are cleaned, surveys will be conducted to determine if the concentrations of radium-226 in soil are within the limits outlined in 40 CFR, Part 192. Conformance with the criteria will be demonstrated by a gamma survey of the area employing the differential, or delta-measurement, technique. This technique involves fitting the detector with a base and a receptacle for a removable high-density filter. By making measurements with and without the filter in place, a gamma radiation level proportional to the radium-226 concentration in soil can be determined. This paper describes the results obtained in the development of the correlation between the gamma survey measurements and the soil radium concentrations

Radioactive Ores and Concentrates (Packaging and Transport) Regulations 1980 (Northern Territory) No. 30 of 21 July 1980

International Nuclear Information System (INIS)

1980-01-01

These Regulations were issued pursuant to the provisions of the 1980 Radioactive Ores and Concentrates (Packaging and Transport) Act. The primary purpose of the Regulations is to lay down specific record-keeping practices for persons licensed to transport and store radioactive material. (NEA) [fr

Determination of soil, sand and ore primordial radionuclide concentrations by full-spectrum analyses of high-purity germanium detector spectra

International Nuclear Information System (INIS)

Newman, R.T.; Lindsay, R.; Maphoto, K.P.; Mlwilo, N.A.; Mohanty, A.K.; Roux, D.G.; Meijer, R.J. de; Hlatshwayo, I.N.

2008-01-01

The full-spectrum analysis (FSA) method was used to determine primordial activity concentrations (ACs) in soil, sand and ore samples, in conjunction with a HPGe detector. FSA involves the least-squares fitting of sample spectra by linear combinations of 238 U, 232 Th and 40 K standard spectra. The differences between the FSA results and those from traditional windows analyses (using regions-of-interest around selected photopeaks) are less than 10% for all samples except zircon ore, where FSA yielded an unphysical 40 K AC

Geochemistry of Mine Waste and Mill Tailings, Meadow Deposits, Streambed Sediment, and General Hydrology and Water Quality for the Frohner Meadows Area, Upper Lump Gulch, Jefferson County, Montana

Science.gov (United States)

Klein, Terry L.; Cannon, Michael R.; Fey, David L.

2004-01-01

Frohner Meadows, an area of low-topographic gradient subalpine ponds and wetlands in glaciated terrane near the headwaters of Lump Gulch (a tributary of Prickly Pear Creek), is located about 15 miles west of the town of Clancy, Montana, in the Helena National Forest. Mining and ore treatment of lead-zinc-silver veins in granitic rocks of the Boulder batholith over the last 120 years from two sites (Frohner mine and the Nellie Grant mine) has resulted in accumulations of mine waste and mill tailings that have been distributed downslope and downstream by anthropogenic and natural processes. This report presents the results of an investigation of the geochemistry of the wetlands, streams, and unconsolidated-sediment deposits and the hydrology, hydrogeology, and water quality of the area affected by these sources of ore-related metals. Ground water sampled from most shallow wells in the meadow system contained high concentrations of arsenic, exceeding the Montana numeric water-quality standard for human health. Transport of cadmium and zinc in ground water is indicated at one site near Nellie Grant Creek based on water-quality data from one well near the creek. Mill tailings deposited in upper Frohner Meadow contribute large arsenic loads to Frohner Meadows Creek; Nellie Grant Creek contributes large arsenic, cadmium, and zinc loads to upper Frohner Meadows. Concentrations of total-recoverable cadmium, copper, lead, and zinc in most surface-water sites downstream from the Nellie Grant mine area exceeded Montana aquatic-life standards. Nearly all samples of surface water and ground water had neutral to slightly alkaline pH values. Concentrations of arsenic, cadmium, lead, and zinc in streambed sediment in the entire meadow below the mine waste and mill tailings accumulations are highly enriched relative to regional watershed-background concentrations and exceed consensus-based, probable-effects concentrations for streambed sediment at most sites. Cadmium, copper, and

Evaluation of maximum radionuclide concentration from decay chains migration in aquifers

International Nuclear Information System (INIS)

Aquino Branco, O.E. de.

1983-01-01

The mathematical formulation of the mechanisms involved in the transport of contaminants in aquifers is presented. The methodology employed is described. A method of calculation the maximum concentration of radionuclides migrating in the underground water, and resulting from one decay chain, is then proposed. As an example, the methodology is applied to a waste basin, built to receive effluents from a hypothectical uranium ore mining and milling facility. (M.A.C.) [pt

Collective sulphide flotation of the polymetallic molybdenic ore

International Nuclear Information System (INIS)

Mazanek, C.; Maselko, J.; Rycerz, L.

1980-01-01

Results of investigations on polymetallic molybdenic ore are presented. The useful minerals of this ore are as follows: molybdenite, sphalerite, galena and chalcopyrite whereas quartz, feldspars, chlorite and sericite are barren rocks. The flotation process parameters are established i.e. the consumption of flotation reagents, the flotation time and the most advantageous grain composition of the ore submitted to flotation. Taking into consideration the established parameters, a collective sulphide flotation of ore and a control flotation of wastes were carried out. The obtained concentrate was submitted to a single cleaning flotation whereby a concentrate was obtained containing: 4,65% Mo, 2,51% Cu, 0,9% Zn, 0,69% Pb, and 1,4% Bi. (author)

Separation of monazite from Rirang ore by floatation method

International Nuclear Information System (INIS)

Affandi, Kosim; Sjahminan, Mainar

1995-01-01

Separation of monazite from Rirang ore has been carried out by means of floatation using oleic acid and pine oil as promoter and frothier reagents, respectively. Several parameters affecting floatation process, i.e. grain size of the ore, pulp pH, and reagents concentration were examnined. The optimal conditions for the process include the use of -100 mesh feed ore, pulp pH 9.0 and 1 kilogram of each oleic acid and pine oil per tonne ore. Based on the conditions, monazite recovery of 90% was achieved with about 20% uranium remain in monazite concentrate. (author). 7 refs, 9tabs, 1 fig

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.

Microbial reduction of iron ore

Science.gov (United States)

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

Method of continuous pressure leaching of ores

International Nuclear Information System (INIS)

Fiala, P.; Baloun, S.; Polansky, M.

1987-01-01

Ore leaching, especially suspensions of ground ore or fine ore fractions from physical treatment was divided into two operations. The former, i.e., ore mixing with technical grade concentrated sulfuric acid proceeded in a separate mixer. The mixture was then transported into an autoclave where the actual leaching proceeded for 2 to 4 hours. The extracted mixture was discharged through the autoclave bottom. The leaching autoclave used can be without any inner structures. The separation of mixing from the actual leaching allows processing ores with high levels of clay components, increasing operating reliability of the facility, reducing consumption of special structural materials and energy, and increasing process efficiency. (E.S.)

Measurements of 234U, 238U and 230Th in excreta of uranium-mill crushermen

International Nuclear Information System (INIS)

Fisher, D.R.; Jackson, P.O.; Brodacynski, G.G.; Scherpelz, R.I.

1982-07-01

Uranium and thorium levels in excreta of uranium mill crushermen who are routinely exposed to airborne uranium ore dust were measured. The purpose was to determine whether 230 Th was preferentially retained over either 234 U or 238 U in the body. Urine and fecal samples were obtained from fourteen active crushermen with long histories of exposure to uranium ore dust, plus four retired crushermen and three control individuals for comparison. Radiochemical procedures were used to separate out the uranium and thorium fractions, which were then electroplated on stainless steel discs and assayed by alpha spectrometry. Significantly greater activity levels of 234 U and 238 U were measured in both urine and fecal samples obtained from uranium mill crushermen, indicating that uranium in the inhaled ore dust was cleared from the body with a shorter biological half-time than the daughter product 230 Th. The measurements also indicated that uranium and thorium separate in vivo and have distinctly different metabolic pathways and transfer rates in the body. The appropriateness of current ICRP retention and clearance parameters for 230 Th in ore dust is questioned

Concentration of gold, sulphide minerals, and uranium oxide minerals by flotation from ores and metallurgical plant products

International Nuclear Information System (INIS)

Weston, D.

1976-01-01

A process is described for the concentration by flotation of gold, gold bearing minerals and uranium oxide minerals from ores and metallurgical plant products. A pulp of a ground ore is agitation conditioned in at least two agitation conditioning stages wherein in at least one stage the pH of the pulp is lowered with an acid agent to within the pH range of about 1.5 to 5.0, and wherein in at least one additional agitation conditioning stage the pH of the pulp is raised to within the pH range of about 6.0 to 11.0 and wherein in at least the last stage prior to flotation at least one collector selected from the group of sulfhydryl anionic collectors is present. Subsequently, the at least two stage agitation conditioned pulp is subjected to flotation to produce a flotation concentrate enriched in at least one of the mineral values from the group consisting of gold, gold bearing minerals and uranium minerals

Feasibility study of the dissolution rates of uranium ore dust, uranium concentrates and uranium compounds in simulated lung fluid

International Nuclear Information System (INIS)

Robertson, R.

1986-01-01

A flow-through apparatus has been devised to study the dissolution in simulated lung fluid of aerosol materials associated with the Canadian uranium industry. The apparatus has been experimentally applied over 16 day extraction periods to approximately 2g samples of < 38um and 53-75um particle-size fractions of both Elliot Lake and Mid-Western uranium ores. The extraction of uranium-238 was in the range 24-60% for these samples. The corresponding range for radium-226 was 8-26%. Thorium-230, lead-210, polonium-210, and thorium-232 were not significantly extracted. It was incidentally found that the elemental composition of the ores studied varies significantly with particle size, the radionuclide-containing minerals and several extractable stable elements being concentrated in the smaller size fraction. Samples of the refined compounds uranium dioxide and uranium trioxide were submitted to similar 16 day extraction experiments. Approximately 0.5% of the uranium was extracted from a 0.258g sample of unsintered (fluid bed) uranium dioxide of particle size < 38um. The corresponding figure for a 0.292g sample of uranium trioxide was 97%. Two aerosol samples on filters were also studied. Of the 88ug uranium initially measured on stage 2 of a cascade impactor sample collected from the yellow cake packing area of an Elliot Lake mill, essentially 100% was extracted over a 16 day period. The corresponding figure for an open face filter sample collected in a fuel fabrication plant and initially measured at 288ug uranium was approximately 3%. Recommendations are made with regard to further work of a research nature which would be useful in this area. Recommendations are also made on sampling methods, analytical methods and extraction conditions for various aerosols of interest which are to be studied in a work of broader scope designed to yield meaningful data in connection with lung dosimetry calculations

Remedial action at the Green River uranium mill tailings site, Green River, Utah: Environmental assessment

International Nuclear Information System (INIS)

1988-07-01

The inactive Green River uranium mill tailings site is one mile southeast of Green River, Utah. The existing tailings pile is within the floodplain boundaries of the 100-year and 500-year flood events. The 48-acre designated site contains eight acres of tailings, the mill yard and ore storage area, four main buildings, a water tower, and several small buildings. Dispersion of the tailings has contaminated an additional 24 acres surrounding the designated site. Elevated concentrations of molybdenum, nitrate, selenium, uranium, and gross alpha activity exceed background levels and the proposed US Environmental Protection Agency (EPA) maximum concentration limits in the groundwater in the unconsolidated alluvium and in the shallow shales and limestones beneath the alluvium at the mill tailings site. The contamination is localized beneath, and slightly downgradient of, the tailings pile. The proposed action is to relocate the tailings and associated contaminated materials to an area 600 feet south of the existing tailings pile where they would be consolidated into one, below-grade disposal cell. A radon/infiltration barrier would be constructed to cover the stabilized pile and various erosion control measures would be taken to ensure the long-term stability of the stabilized pile. 88 refs., 12 figs., 20 tabs

Development and functioning of microorganisms in concentration cycles of sulfide copper-nickel and non-sulfide apatite-nepheline ores

Directory of Open Access Journals (Sweden)

Fokina N. V.

2017-03-01

Full Text Available The number and trophic diversity of bacteria in flotation samples of apatite-nepheline and sulfide copper-nickel ores at the concentration plants of JSC "Apatite" and Kola Mining and Metallurgical Company have been determined. The study of the size and diversity of the microbiota has been conducted by culture on selective nutrient media. The total number and biomass of bacteria have been considered by fluorescence microscopy using Cyclopore polycarbonate membrane filters. Bacteria have been identified by molecular genetic methods. The least amount of both saprotrophic and other trophic groups of bacteria has been observed in the samples of ore and recycled water as at the concentrating factory of Apatit JSC, and also at the plant "Pechenganikel". It has been found out that the bacteria contained in the ore and recycling water flowing from the tailings increased their number during the flotation process due to coming of the nutrients with the flotation reagents, aeration and increased temperature. Strains which occurrence is more than 60 % have been extracted from recycled water and basic flotation products and classified as Pseudomonas. Two strains with occurrence of more than 60 % have been discovered at Apatit JSC and classified as Stenotrophomonas and Acinetobacter. The number of fungi in the cycle of apatite-nepheline ore enrichment at the factories is very low (1 to 24 CFU / 1 ml or 1 g of ore. Fungi of the genus Penicillium have been dominated, fungi of the genera Acremonium, Aureobasidium, Alternaria, Chaetomium have also been detected. At the plant "Pechenganikel" species Aspergillus fumigatus, Penicillium aurantiogriseum and P. glabrum have been extracted. It has been shown that the bacteria deteriorate the apatite flotation as a result of their interaction with active centers of calcium-containing minerals and intensive flocculation decreasing the floatation selectivity. Also some trend of copper and nickel recovery change has been

Environmental monitoring data review of a uranium ore processing facility in Argentina

International Nuclear Information System (INIS)

Bonetto, J.

2014-01-01

An uranium ore processing facility in the province of Mendoza (Argentina) that has produced uranium concentrate from 1954 to 1986 is currently undergoing the last steps of environmental restoration. The operator has been performing post-closure environmental monitoring since 1986, while the Nuclear Regulatory Authority (ARN) has been carrying out its own independent radiological environmental monitoring for verification purposes since its creation, in 1995. A detailed revision of ARN´s monitoring plan for uranium mining and milling facilities has been undergoing since 2013, starting with this particular site. Results obtained from long-time sampling locations (some of them currently unused) have been analyzed and potentially new sampling points have been studied and proposed. In this paper, some statistical analysis and comparison of sampling-points’ datasets are presented (specifically uranium and radium concentration in groundwater, surface water and sediments) with conclusions pertaining to their keeping or discarding as sampling points in future monitoring plans. (author)

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.

Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry

International Nuclear Information System (INIS)

Gbadago, J K; Darko, E O; Faanhof, A; Schandorf, C

2011-01-01

The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits. The environmental impact of the radionuclides is therefore expected to be low in this mining environment.

Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Gbadago, J K; Darko, E O [Ghana Atomic Energy Commission, PO Box LG 80, Legon, Accra (Ghana); Faanhof, A [South African Nuclear Energy Corporation, PO Box 582, Pretoria 0001 (South Africa); Schandorf, C, E-mail: jgbada@yahoo.com [School of Nuclear and Allied Sciences, University of Ghana, Legon, Accra (Ghana)

2011-09-01

The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits. The environmental impact of the radionuclides is therefore expected to be low in this mining environment.

Completion of the uranium mill tailings remedial project and cleanup of the former mill site at Grand Junction, Colorado

International Nuclear Information System (INIS)

Rael, G.J.; Cox, S.W.; Artiglia, E.W.

2000-01-01

The United States Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Surface Project has successfully completed the cleanup of 22 former uranium mill sites, more than 5400 vicinity properties, and has constructed 18 entombment cells. The Project has recently received the United States Nuclear Regulatory Commission's approval and certification for the last two disposal sites, with these sites being placed under the general license for long term custodial care of residual radioactive material. The UMTRA site located at Grand Junction, Colorado is a good example of the technical, political, economic, and public relations challenges that were overcome in achieving success. The UMTRA Team discussed, negotiated, planned, and eventually acted on this uranium mill tailings problem and brought the project to a successful conclusion for the community. From the early 1940s through the 1970s, uranium ore was mined in significant quantities under United States federal contracts for the government's national defence programmes, i.e. the Manhattan Engineering District and Atomic Energy Commission programmes. The problem started as the need for uranium decreased in the late 1960s, resulting in mills shutting down, leaving behind large quantities of process waste tailings and contaminated mill buildings. The former Climax Uranium Company mill site in Grand Junction was one of the largest of these sites. (author)

Simple, cost effective method for determination of phosphorus in uranium ore concentrate

International Nuclear Information System (INIS)

Misra, U.B.; Ramamurty, Vasantha; Dutta, M.; Balaji Rao, Y.; Subba Rao, Y.

2015-01-01

In this paper determination of phosphate as phosphorus in uranium ore concentrate has been described. The method used is spectrophotometric determination of phosphorus as phospho-molybdenum blue complex. As uranyl ion do not absorb in 600-900 nm range of visible region in the present medium, the phosphomolybdenum blue complex formation which is having maximum absorbance at 825 nm is exploited for determination of phosphorus. The molar absorptivity coefficient with and without the presence of uranium matrix are 2.6048 x 10 4 and 2.6730 x 10 4 lmol -1 cm -1 . The effect of matrix is not evident from the experiment carried out. (author)

Optimization of copper ore concentration processing by means of radioactive tracers

International Nuclear Information System (INIS)

Petryka, L.; Przewlocki, K.

1989-01-01

Flotation of polymetallic ores in the Polish Lower Silesian Basin was taken as an example for the optimization of copper ore processing using radioactive tracers. An original stochastic mathematical model (stream model) was proposed to minimize copper losses in tailing. A detailed procedure of measurement is presented as well as the experimental data and their interpretation. On the basis of this research copper losses in tailing can be reduced to one third. (author)

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

Nitric acid leaching of radium and other significant radionuclides from uranium ores and tailings

International Nuclear Information System (INIS)

Ryon, A.D.; Hurst, F.J.; Seeley, F.G.

1977-08-01

Nitric acid leaching of representative uranium ores and mill tailings from the western U.S. mining districts removes up to 98% of the 226 Ra and 230 Th, yielding a residue containing 17 to 60 pCi of radium per gram. At best, this is an order of magnitude greater than that in surrounding soils, but about the same level as a standard proposed for building materials in the United Kingdom. Data are also presented on the water penetration and leaching of tailings, the solubility of BaSO 4 , and radon emanation coefficients of ores, tailings, and nitric acid-leached residues

Escherichia coli Concentrations in the Mill Creek Watershed, Cleveland, Ohio, 2001-2004

Science.gov (United States)

Brady, Amie M.G.

2007-01-01

Mill Creek in Cleveland, Ohio, receives discharges from combined-sewer overflows (CSOs) and other sanitary-sewage inputs. These discharges affect the water quality of the creek and that of its receiving stream, the Cuyahoga River. In an effort to mitigate this problem, the Northeast Ohio Regional Sewer District implemented a project to eliminate or control (by reducing the number of overflows) all of the CSOs in the Mill Creek watershed. This study focused on monitoring the microbiological water quality of the creek before and during sewage-collection system modifications. Routine samples were collected semimonthly from August 2001 through September 2004 at a site near a U.S. Geological Survey stream gage near the mouth of Mill Creek. In addition, event samples were collected September 19 and 22, 2003, when rainfall accumulations were 0.5 inches (in.) or greater. Concentrations of Escherichia coli (E. coli) were determined and instantaneous discharges were calculated. Streamflow and water-quality characteristics were measured at the time of sampling, and precipitation data measured at a nearby precipitation gage were obtained from the National Oceanic and Atmospheric Administration. Concentrations of E. coli were greater than Ohio's single-sample maximum for primary-contact recreation (298 colony-forming units per 100 milliliters (CFU/100 mL)) in 84 percent of the routine samples collected. In all but one routine sample E. coli concentrations in samples collected when instantaneous streamflows were greater than 20 cubic feet per second (ft3/s) were greater than Ohio's single-sample maximum. When precipitation occurred in the 24-hour period before routine sample collection, concentrations were greater than the maximum in 89 percent of the samples as compared to 73 percent when rainfall was absent during the 24 hours prior to routine sample collection. Before modifications to the sewage-collection system in the watershed began, E. coli concentrations in Mill Creek

Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

International Nuclear Information System (INIS)

Momeni, M.H.; Lindstrom, J.B.; Dungey, C.E.; Kisieleski, W.E.

1979-11-01

Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m 3 on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m 3 . Average working-level background is 3.6 x 10 -3

Evaluation the effect of uranium ore concentrations on the cyc2 gene expression in the mutated Acidithiobacillus sp. FJ2

Directory of Open Access Journals (Sweden)

Faezeh Fatemi

2018-06-01

Full Text Available Introduction: The uranium bioleaching process is performed using Acidithiobacillus ferrooxidans. This bacterium is capable of iron oxidation by an electron transport chain. One of the most important components of this chain is the cyc2 gene product that involved in the oxidation process of iron. Materials and methods: Evaluation of UV mutated (60, 120 and 180s Acidithiobacillus sp. FJ2 cyc2gene in the presence of uranium ore concentrations, has been implemented in this project. For this purpose, the original and mutated bacteria were cultivated in the presence of uranium ore concentrations (5, 10, 15, 25 and 50%. Uranium extraction, variation of pH and Eh values were measured at 24 h intervals. Then, when the uranium extraction yield reached to 100%, gene expressions of cyc2 original and mutatedAcidithiobacillus sp. FJ2 were analyzed using Real-time PCR method. Results: The results of the experiments showed that, with increasing pulp density, the uranium extraction rate and oxidation activity of bacteria were reduced. In addition, the result of cyc2 gene expression showed that the target gene expression increases in the presence of uranium ore compared to sample with absence of uranium ore, andwith further increase of pulp density, due to the toxicity of uranium, shows a decreasing trend. Discussion and conclusion: The results of this study indicated that the mutation in the bacterium has a positive effect on the uranium bioleaching process, which can play an important role in the process of uranium bioleaching at high concentrations. In addition, with increasing pulp density due to uranium toxicity, there is a decreasing trend in the process of uranium extraction, which indicates the important role of this factor in the uranium bioleaching process.

Inhalation of uranium ores

International Nuclear Information System (INIS)

Stuart, B.O.; Jackson, P.O.

1975-01-01

In previous studies the biological dispositions of individual long-lived alpha members of the uranium chain ( 238 U, 234 U and 230 Th) were determined during and following repeated inhalation exposures of rats to pitchblende (26 percent U 3 O 8 ) ore. Although finely dispersed ore in secular equilibrium was inhaled, 230 Th/ 234 U radioactivity ratios in the lungs rose from 1.0 to 2.5 during 8 weeks of exposures and increased to 9.2 by four months after cessation of exposures. Marked non-equilibrium levels were also found in the tracheobronchial lymph nodes, kidneys, liver, and femur. Daily exposures of beagle dogs to high levels of this ore for 8 days resulted in lung 230 Th/ 234 U ratios of >2.0. Daily exposures of dogs to lower levels (0.1 mg/1) for 6 months, with sacrifice 15 months later, resulted in lung and thoracic lymph node 230 Th/ 234 U ratios ranging from 3.6 to 9 and nearly 7, respectively. The lungs of hamsters exposed to carnotite (4 percent U 3 O 8 ) ore in current lifespan studies show 230 Th/ 234 U ratios as high as 2.0 during daily inhalation of this ore in secular equilibrium. Beagle dogs sacrificed after several years of daily inhalations of the same carnotite ore plus radon daughters also showed marked non-equilibrium ratios of 230 Th/ 234 U, ranging from 5.6 to 7.4 in lungs and 6.2 to 9.1 in thoracic lymph nodes. This pattern of higher retention of 230 Th than 234 U in lungs, thoracic lymph nodes, and other tissues is thus consistent for two types of uranium ore among several species and suggests a reevaluation of maximum permissible air concentrations of ore, currently based only on uranium content

Study on Yen Phu rare earth ore concentrate treatment technology and separation of major heavy rare earth elements by solvent extraction method

International Nuclear Information System (INIS)

Le Ba Thuan; Pham Quang Trung; Vu Lap Lai

2003-01-01

1. Yenphu rare earth ore concentrate treatment by alkali under pressure: On the base of studying mineral and chemical compositions of Yenphu rare earth ore concentrate containing 28% TREO and conditions for digestion of ore concentrate by alkali under pressure such as ore concentrate/ NaOH ratio, alkali concentration, pressure and temperature at bench scale (100 gram and 5 kg per batch), the optimal conditions for decomposition of REE ore concentrate have been determined. The yield of the decomposition stage is about 90%. The studies on alkali washing, REE leaching by HCl, pH for leaching process, and iron and radioactive impurities removing by Na 2 S + Na 2 PO 4 have been carried out. The obtained results show that mixture of Na 2 S 5% + Na2PO 4 1% is effective in iron and radioactive impurities removing. The obtained REE oxides get purity of > 99% and meet the need of solvent extraction (SX) individual separation of rare earth elements. The schema for recovery of REEs from Yenphu REE ore concentrate by alkali decomposition under high pressure has been proposed. 2. Fractionation of Yenphu rare earth mixture into subgroups by solvent extraction with PC88A: On the base of simulation program, the parameters for fractional process of rare earths mixture into subgroups by solvent extraction with PC88A have been proposed and determined by experimental verification on mixer-settler set. According to this process, rare earths mixture fractionated into yttrium and light subgroups. In their turn, the light subgroup was separated into light (La, Ce, Pr, Nd) and middle (Sm, Eu, Gd) subgroups. The average yield of the process reached value > 95%. The composition of light subgroup meets the needs for individual separation of Gd, Eu, and Sm. 3. Separation and purification of yttrium: The process for recovery of yttrium consists of two stages: upgrade to get high quality Y concentrate by PC88A and purification by Aliquat 336 in NH 4 SCN-NH 4 Cl medium. The process parameter for

An Overview of Process Monitoring Related to the Production of Uranium Ore Concentrate

Energy Technology Data Exchange (ETDEWEB)

McGinnis, Brent [Innovative Solutions Unlimited, LLC

2014-04-01

Uranium ore concentrate (UOC) in various chemical forms, is a high-value commodity in the commercial nuclear market, is a potential target for illicit acquisition, by both State and non-State actors. With the global expansion of uranium production capacity, control of UOC is emerging as a potentially weak link in the nuclear supply chain. Its protection, control and management thus pose a key challenge for the international community, including States, regulatory authorities and industry. This report evaluates current process monitoring practice and makes recommendations for utilization of existing or new techniques for managing the inventory and tracking this material.

Sintering-alkaline processing of borosilicate ores of Tajikistan

International Nuclear Information System (INIS)

Nazarov, F.A.

2018-01-01

The aim of the work is to study the processes of decomposition of boron-containing ore by sintering with NaOH, finding the optimal parameters of the decomposition process, studying the kinetics of processes and developing the technological foundations for ore processing. The processes of borosilicate ore processing were studied by sintering with NaOH. Possible mechanisms of chemical reactions of the process of sintering-alkaline decomposition of boron-containing ore are established, the results of which are substantiated by physicochemical methods of analysis. A principal technological scheme for processing of borosilicate ores by a sintering-alkaline method has been developed. In the first chapter, data on alkaline and caking processes for processing boron-containing and aluminium comprising raw materials are available in the literature. Based on this, the directions of our own research are outlined. The second chapter is devoted to the study of the chemical and mineralogical compositions of borosilicate ores and their concentrates with the help of X-ray phase and chemical analysis methods, the stoichiometric calculation of the formation of aluminum, iron, and boron salts has been carried out, and a thermodynamic analysis of the processes of sintering borosilicate ores with alkali has been considered. The third chapter presents the results of a study of sintering-alkaline method of processing of initial borosilicate ore of the Ak-Arkhar Deposit and its concentrate without calcination and after calcination. The kinetics of sintering of borosilicate ores with sodium hydroxide was studied. The optimal conditions of borosilicate ore sintering before and after the preliminary calcination with alkali were determined. Optimal parameters of the sintering process have been found: sintering temperature 800-8500 deg C, duration of the process - 60 minutes, mass ratio of NaOH to raw materials 2: 1. The conditions for sintering of borosilicate concentrate with alkali have been

Water leaching of titanium from ore flotation residue.

Science.gov (United States)

Jaworska, Malgorzata M; Guibal, Eric

2003-01-01

Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

Calibration of a PHREEQC Based Geochemical Model to Predict Surface Water Discharge Compositions from an Operating Uranium Mill in the Athabasca Basin

International Nuclear Information System (INIS)

Mahoney, John J.; Frey, Ryan A.

2014-01-01

Objectives: • Develop predictive model to estimate concentrations in the Sink Vulture Treated Effluent Management System (SVTEMS) for AREVA Resources Canada McClean Lake Mill: • Sink Reservoir, Vulture and McClean Lakes; • PHREEQC based calculations for geochemistry; • Employ PHREEPLOT for data fittings. • Model designed to predict concentrations in response to changing conditions, including: • Different ores; • Different processes; • Different waters sources; • Changing treatment conditions; • This is a batch mixing model: • Think well mixed beakers; • Each model represents one year; • No year-to-year carry over in models

National/international R and D programs on uranium mill tailings

International Nuclear Information System (INIS)

Hamel, P.E.

1981-05-01

The mining and milling of uranium ores results in the production of large quantities of wastes containing low concentrations of radionuclides such as uranium, thorium, radium, radon and their daughter products. The current concern of the regulatory authorities is with the extent of the problems and the disposal methods that must be required now to ensure that an acceptable level of protection is maintained in the long term. This concern is the subject of a number of R and D programs. In Canada, the Technical Planning Group on Uranium Tailings was established to review ongoing activities and to plan a research program on the management of wastes after the mine and mill have shut down. The Group has completed its review and a report containing its conclusions and recommendations for a proposed national R and D program has been prepared. Included is a proposal for a centralized organizational structure for the coordination and managment of the total program which is to be supported jointly by the federal government, two (Ontario, Saskatchewan) provincial governments, and uranium producers. At the international level, the Nuclear Energy Agency originated, in 1979, a program to study the extent of the long-term problems of uranium mill tailings, and to develop an internationally acceptable methodology for making rational decisions regarding their long-term management taking into account the ICRP principles and system of dose limitation

Critical evaluation of safety and radiological protection requirements adopted for the transport of uranium and thorium ores and concentrates

International Nuclear Information System (INIS)

Mezrahi, Arnaldo; Crispim, Verginia R.

2009-01-01

This work evaluates in a critical way the safety and radiological protection recommendations established by the International Atomic Energy Agency - IAEA and adopted national and internationally, for the transport of uranium and thorium ores and concentrates, known according the transport regulations, as being of the Low Specific Activity Material Type-I, LSA-I, basing on more realistic scenarios than the presently existent, aiming at the determination of maximum exposure levels of radiation as well as the maximal contents of those materials in packages and conveyance. A general overview taking into account the scenarios foreseen by the regulations of the IAEA pointed out for a need of a better justification of the requirements edited by the Agency or should be used to support a request of revision of those regulations, national and internationally adopted, in the pertinent aspects to the transport of uranium and thorium ores and concentrates. (author)

A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

International Nuclear Information System (INIS)

Xia Dechang; Liu Chao

2012-01-01

On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

Chapter 3. Classical method of uranium leaching from ores and reasons for incomplete recovery at dumps of State Enterprise 'VOSTOKREDMET'. 3.3. Basic regularities of uranium ores leaching

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

2012-01-01

Present article is devoted to basic regularities of uranium ores leaching. It was found that the basic method of uranium ores enrichment and producing of reasonably rich and pure uranium concentrates (usually technical uranium oxide) is a chemical concentration concluded in selective uranium leaching from ore raw materials with further, uranium compounds - so called uranium chemical concentrates. Such reprocessing of uranium ores with the purpose of uranium chemical concentrates production, currently, are produced everywhere by hydrometallurgical methods. This method in comparison with enrichment and thermal reprocessing is a universal one. Hydrometallurgy - the part of chemical technology covering so called moist methods of metals and their compounds (in the current case, uranium) extraction from raw materials, where they are contained. It can be ores or ore concentrates produced by radiometric, gravitational, floatation enrichment, sometimes passed through high-temperature reprocessing or even industry wastes. The basic operation in hydrometallurgy is its important industrial element - metal or metals leaching as one or another compound. Leaching is conversion of one or several components to solution under impact of relevant technical solvents: water, water solutions, acids, alkali or base, solution of some salts and etc. The basic purpose of leaching in uranium technology is to obtain the most full and selective solution of uranium.

Management of wastes from the refining and conversion of uranium ore concentrate to uranium hexafluoride

International Nuclear Information System (INIS)

1981-01-01

This report is the outcome of an IAEA Advisory Group Meeting on ''Waste Management Aspects in Relation to the Refining of Uranium Ore Concentrates and their Conversion to Uranium Hexafluoride'', which was held in Vienna from 17 to 21 December 1979. The report summarizes the main topics discussed at the meeting and gives an overview of uranium refining processes, being used in nuclear industry. The meeting was organized by the International Atomic Energy Agency, Radioactive Waste Management Section

Status report from India [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Fareeduddin, S [Atomic Energy Establishment, Trombay, Bombay (India)

1967-06-15

from the ore deposits at Jadugoda, assaying 0. 06-0.07% U{sub 3}O{sub 8}, first on the laboratory and then on a pilot plant scale. Based on this work, a mill, capable of treating 1000 tonnes of ore per day, is being set up at Jadugoda and is expected to go into production during 1966. It is hoped that the operation of this mill will provide an impetus and experience towards concerted and determined efforts to develop methods which will cut down costs of treating ores from the thrust belt. A brief outline of the work done on Jadugoda ore and the process that was finally selected is given. (author)

Concentration and Separation of Scandium from Ni Laterite Ore Processing Streams

Directory of Open Access Journals (Sweden)

Şerif Kaya

2017-12-01

Full Text Available The presence of a considerable amount of scandium in lateritic nickel-cobalt ores necessitates the investigation of possible processing alternatives to recover scandium as a byproduct during nickel and cobalt production. Therefore, in this study, rather than interfering with the main nickel-cobalt production circuit, the precipitation-separation behavior of scandium during a pH-controlled precipitation process from a synthetically prepared solution was investigated to adopt the Sc recovery circuit into an already existing hydrometallurgical nickel-cobalt hydroxide processing plant. The composition of the synthetic solution was determined according to the hydrometallurgical nickel laterite ore processing streams obtained from a HPAL (high-pressure sulphuric acid leaching process. In order to selectively precipitate and concentrate scandium with minimum nickel and cobalt co-precipitation, the pH of the solution was adjusted by CaCO3, MgO, Na2CO3, and NaOH. It was found that precipitation with MgO or Na2CO3 is more advantageous to obtain a precipitate containing higher amounts of scandium with minimum mass when compared to the CaCO3 route, which makes further processing more viable. As a result of this study, it is proposed that by a simple pH-controlled precipitation process, scandium can be separated from the nickel and cobalt containing process solutions as a byproduct without affecting the conventional nickel-cobalt hydroxide production. By further processing this scandium-enriched residue by means of leaching, SX (solvent extraction, and precipitation, an intermediate (NH42NaScF6 product can be obtained.

Beneficiation studies of Bajaur manganese ore by different processing techniques

International Nuclear Information System (INIS)

Riaz, M.; Khan, F.U.; Yamin, A.; Bilquees, R.; Muhammad, N.

2010-01-01

The manganese ore of Bajaur Agency of Pakistan was subjected to flotation, heavy medium separation, gravity concentration and magnetic separation techniques for beneficiation. The original composition of the manganese ore was 45.56% Mn , 4% Fe/sub 2/O/sub 3/, 40% SiO/sub 2/. The Mn content was raised to a maximum 48.76 % in the concentrate with the recovery of 67.78 % through flotation technique. Other techniques rendered marginal increase in Mn concentration against the theoretical possibility of substantial enrichment by rejecting the 20 % gangue minerals. The separation of manganese minerals from associated gangue was difficult, due to mineralogical complexity of the ore, extreme fineness of the particle size, texture and minerals intergrowth. High Mn/Fe ratio, phosphorus, and silica contents were within tolerable limits for utilisation of the ore in ferro-manganese production. (author)

X-ray fluorescence separation of pure lead-zinc ores

International Nuclear Information System (INIS)

Lapshin, S.A.; Filippov, O.K.; Khachatryan, L.S.; Rudnev, B.P.

1987-01-01

To evaluate the influence of the previous concentration of polymetallic ores by the radiometric separation method on indices of flotation and gravitation enrichments, investigations were carried out using ore sample (1.94%Pb, 1.13% Zn) from a lead-zink ore deposit. It is shown that the results obtained on the enrichment of the ore and products of X-ray radiometric separation are similar. However previous removal (up to 40%) of dead rock permits to reduce sharply grinding and transpot costs

Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

Energy Technology Data Exchange (ETDEWEB)

Momeni, M H; Lindstrom, J B; Dungey, C E; Kisieleski, W E

1979-11-01

Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m/sup 3/ on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m/sup 3/. Average working-level background is 3.6 x 10/sup -3/.

Optimization of dissolution process parameters for uranium ore concentrate powders

Energy Technology Data Exchange (ETDEWEB)

Misra, M.; Reddy, D.M.; Reddy, A.L.V.; Tiwari, S.K.; Venkataswamy, J.; Setty, D.S.; Sheela, S.; Saibaba, N. [Nuclear Fuel Complex, Hyderabad (India)

2013-07-01

Nuclear fuel complex processes Uranium Ore Concentrate (UOC) for producing uranium dioxide powder required for the fabrication of fuel assemblies for Pressurized Heavy Water Reactor (PHWR)s in India. UOC is dissolved in nitric acid and further purified by solvent extraction process for producing nuclear grade UO{sub 2} powder. Dissolution of UOC in nitric acid involves complex nitric oxide based reactions, since it is in the form of Uranium octa oxide (U{sub 3}O{sub 8}) or Uranium Dioxide (UO{sub 2}). The process kinetics of UOC dissolution is largely influenced by parameters like concentration and flow rate of nitric acid, temperature and air flow rate and found to have effect on recovery of nitric oxide as nitric acid. The plant scale dissolution of 2 MT batch in a single reactor is studied and observed excellent recovery of oxides of nitrogen (NO{sub x}) as nitric acid. The dissolution process is automated by PLC based Supervisory Control and Data Acquisition (SCADA) system for accurate control of process parameters and successfully dissolved around 200 Metric Tons of UOC. The paper covers complex chemistry involved in UOC dissolution process and also SCADA system. The solid and liquid reactions were studied along with multiple stoichiometry of nitrous oxide generated. (author)

Investigating concentration distributions of arsenic, gold and antimony in grain-size fractions of gold ore using instrumental neutron activation analysis

International Nuclear Information System (INIS)

Nyarku, M.; Nyarko, B.J.B.; Serfor-Armah, Y.; Osae, S.

2010-01-01

Instrumental neutron activation analysis (INAA) has been used to quantify concentrations of arsenic (As), gold (Au) and antimony (Sb) in grain-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd., was fractionated into 14 grain-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 μm and grains >2000 μm were not considered for analysis. Result of the sieving was analysed with easysieve (registered) software. The<36 μm subfraction was found to be the optimum, hosting bulk of all three elements. Arsenic was found to be highly concentrated in<36-100 μm size fractions and erratically distributed in from 150 μm fraction and above. For gold, with the exception of the subfraction <36 μm which had exceptionally high concentration, the element was found to be approximately equally distributed in all the size fractions but slightly 'played out' in 150-400 μm size fractions. Antimony occurrence in the sample was relatively high in <36 μm size fraction followed by 600, 800, 400 and 36 μm size fractions in that order. Gold content in the sample was comparatively far greater than arsenic and antimony; this is indicative of level of gold mineralization in the concession where the sample ore was taken. The concentration of gold in the composite sample was in the range 564-8420 ppm as compared to 14.33-186.92 ppm for arsenic and 1.09-9.48 ppm for antimony. Elemental concentrations were correlated with each other and with grain-size fractions and the relationships between these descriptive parameters were established.

Uranium abundance in some sudanese phosphate ores

International Nuclear Information System (INIS)

Adam, A.A.; Eltayeb, M.A.H.

2009-01-01

This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

A review of the Code of Practice for the Management of Radioactive Wastes from the Mining and Milling of Radioactive Ores

International Nuclear Information System (INIS)

1984-01-01

This paper concentrates on the philosophy of the Code and its guidelines. It is considered that the intent of the Code and the legal status of the guidelines need to be clarified. Mill tailings management and water management at Ranger are also considered

Total Ore Processing Integration and Management

Energy Technology Data Exchange (ETDEWEB)

Leslie Gertsch

2006-05-15

This report outlines the technical progress achieved for project DE-FC26-03NT41785 (Total Ore Processing Integration and Management) during the period 01 January through 31 March of 2006. (1) Work in Progress: Minntac Mine--Graphical analysis of drill monitor data moved from two-dimensional horizontal patterns to vertical variations in measured and calculated parameters. The rock quality index and the two dimensionless ({pi}) indices developed by Kewen Yin of the University of Minnesota are used by Minntac Mine to design their blasts, but the drill monitor data from any given pattern is obviously not available for the design of that shot. Therefore, the blast results--which are difficult to quantify in a short time--must be back-analyzed for comparison with the drill monitor data to be useful for subsequent blast designs. {pi}{sub 1} indicates the performance of the drill, while {pi}{sub 2} is a measure of the rock resistance to drilling. As would be expected, since a drill tends to perform better in rock that offers little resistance, {pi}{sub 1} and {pi}{sub 2} are strongly inversely correlated; the relationship is a power function rather than simply linear. Low values of each Pi index tend to be quantized, indicating that these two parameters may be most useful above certain minimum magnitudes. (2) Work in Progress: Hibtac Mine--Statistical examination of a data set from Hibtac Mine (Table 1) shows that incorporating information on the size distribution of material feeding from the crusher to the autogenous mills improves the predictive capability of the model somewhat (43% vs. 44% correlation coefficient), but a more important component is production data from preceding days (26% vs. 44% correlation coefficient), determined using exponentially weighted moving average predictive variables. This lag effect likely reflects the long and varied residence times of the different size fragments in the grinding mills. The rock sizes are also correlated with the geologic

Influence of a High-Pressure Comminution Technology on Concentrate Yields in Copper Ore Flotation Processes

Directory of Open Access Journals (Sweden)

Saramak D.

2014-10-01

Full Text Available The article concerns the issues of flotation process effectiveness in relationship to the operating conditions of a high-pressure comminution process course. Experimental programme covering a flotation laboratory batch tests was a verification technique of a high-pressure crushing operations course. The most favorable values of flotation concentrate weight recoveries were obtained for the pressing force 6 kN and 4% of the feed moisture. It was also determined the model of the concentrate weight recovery as a function of pressing force in the press and feed moisture content. This model was the basis for the optimization of effects of copper ore flotation processes preceded in high-pressure crushing operation in roller presses.

Beneficiation of the gold bearing ore by gravity and flotation

Science.gov (United States)

Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven

2012-02-01

Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

Fission track method for uranium ore exploration

International Nuclear Information System (INIS)

Guo Shilun; Deng Xinlu; Sun Shengfen; Meng Wu; Zhang Pengfa; Hao Xiuhong

1986-01-01

The uranium concentrations in natural water collected in the fields of uranium ore exploration with fission track method have been determined. It shows that the results of fission track method are consistent with that of fluoro-colorimetry and laser fluorometry for the same samples of water with uranium concentration in the region of 10 -4 to 10 -8 g/l. For water samples with lower uranium concentration (≤10 -8 g/l), the fission track method can still give accurate or referential results, but the other two methods failed. The reproducibility of fission track method was checked and discussed by using samples collected in the same fields of uranium ore exploration. The effects of the concentration of the impurities in natural water on determination of uranium concentration were analysed and discussed as well

Composite control for raymond mill based on model predictive control and disturbance observer

Directory of Open Access Journals (Sweden)

Dan Niu

2016-03-01

Full Text Available In the raymond mill grinding process, precise control of operating load is vital for the high product quality. However, strong external disturbances, such as variations of ore size and ore hardness, usually cause great performance degradation. It is not easy to control the current of raymond mill constant. Several control strategies have been proposed. However, most of them (such as proportional–integral–derivative and model predictive control reject disturbances just through feedback regulation, which may lead to poor control performance in the presence of strong disturbances. For improving disturbance rejection, a control method based on model predictive control and disturbance observer is put forward in this article. The scheme employs disturbance observer as feedforward compensation and model predictive control controller as feedback regulation. The test results illustrate that compared with model predictive control method, the proposed disturbance observer–model predictive control method can obtain significant superiority in disturbance rejection, such as shorter settling time and smaller peak overshoot under strong disturbances.

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

Liquid wastes from mining and milling of uranium ores - a laboratory study of treatment methods

International Nuclear Information System (INIS)

Ryan, R.K.; Alfredson, P.G.

1976-10-01

Methods of reducing the concentration of contaminants in mine water and in the acidic raffinate from uranium milling operations have been studied. Lime, limestone, caustic soda and lime-soda ash mixtures were compared as reagents for neutralising raffinates and for removing amines and heavy metals including radium from solution. All methods of neutralisation reduced contaminant levels significantly. Two-stage neutralisation using limestone in the first stage to pH 4, followed by second stage lime treatment appears to be an economically attractive approach. This method usually gave the lowest residual radium concentration provided the solids from the first stage were not removed before adding lime. Radium can be further removed from neutralised raffinates or from mine water conditioned with sulphate by the addition of barium chloride to co-precipitate the sulphates of barium and radium. The concentration of radium was readily reduced to less than 3 pCi l -1 by adding 10 mg Ba l -1 raffinate. For mine waters conditioned to 0.01 M in sulphate, barium additions of 20 mg l -1 were required to attain the same radium concentrations. Adsorption on barytes was also effective in removing radium from conditioned mine water and neutralised raffinates. (author)

Impact Load Behavior between Different Charge and Lifter in a Laboratory-Scale Mill.

Science.gov (United States)

Yin, Zixin; Peng, Yuxing; Zhu, Zhencai; Yu, Zhangfa; Li, Tongqing

2017-07-31

The impact behavior between the charge and lifter has significant effect to address the mill processing, and is affected by various factors including mill speed, mill filling, lifter height and media shape. To investigate the multi-body impact load behavior, a series of experiments and Discrete Element Method (DEM) simulations were performed on a laboratory-scale mill, in order to improve the grinding efficiency and prolong the life of the lifter. DEM simulation hitherto has been extensively applied as a leading tool to describe diverse issues in granular processes. The research results shown as follows: The semi-empirical power draw of Bond model in this paper does not apply very satisfactorily for the ball mills, while the power draw determined by DEM simulation show a good approximation for the measured power draw. Besides, the impact force on the lifter was affected by mill speed, grinding media filling, lifter height and iron ore particle. The maximum percent of the impact force between 600 and 1400 N is at 70-80% of critical speed. The impact force can be only above 1400 N at the grinding media filling of 20%, and the maximum percent of impact force between 200 and 1400 N is obtained at the grinding media filling of 20%. The percent of impact force ranging from 0 to 200 N decreases with the increase of lifter height. However, this perfect will increase above 200 N. The impact force will decrease when the iron ore particles are added. Additionally, for the 80% of critical speed, the measured power draw has a maximum value. Increasing the grinding media filling increases the power draw and increasing the lifter height does not lead to any variation in power draw.

Uranium mill tailings remediation in the USA. A history and lessons learned - 59407

International Nuclear Information System (INIS)

Rima, Steve

2012-01-01

Document available in abstract form only. Full text of publication follows: Since the 1940's uranium ores have been processed at various locations in the United States to extract and produce uranium and other concentrated materials, first for government (weapons) research and production, and then for nuclear power production. The tailings residue from the uranium milling process contained radioactive (primarily Ra-226) and hazardous chemicals. Large volumes of tailings were produced during the milling process. In the early history of this process the tailings were not recognized as hazardous and were released to the general public for a wide variety of uses, resulting in significant spread of contamination in the vicinity of many operating mills. In the late 1960's and early 1970's laws were enacted at the state and federal level to begin to deal with the legacy of this contamination. Over the course of the next several decades various regulatory agencies were responsible for remediating these sites. Different approaches were used, different end points and definitions of clean were used, and very large sums of public funding were spent on remediating these sites. Rarely was the cost commensurate with the risk reduction obtained through remediation. This paper will present an overview of the history of the uranium mill tailings regulatory and remediation program in the United States, the cost of the program compared to risk reduction, successes and failures, and important lessons learned that should be applied to future efforts in this area. (author)

Uranium mill tailings management

International Nuclear Information System (INIS)

1982-01-01

Facilities for the disposal of uranium mill tailings will invariably be subjected to geomorphological and climatological influences in the long-term. Proceedings of a workshop discuss how the principles of geomorphology can be applied to the siting, design, construction, decommissioning and rehabilitation of disposal facilities in order to provide for long-term containment and stability of tailings. The characteristics of tailings and their behaviour after disposal influence the potential impacts which might occur in the long-term. Proceedings of another workshop examine the technologies for uranium ore processing and tailings conditioning with a view to identifying improvements that could be made in such characteristics

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.

Management and control of radioactive wastes from uranium-milling operations

International Nuclear Information System (INIS)

Kennedy, R.H.; Deal, L.J.; Haywood, F.F.; Goldsmith, W.A.

1977-01-01

Of the 39 privately owned mills that produced and sold uranium to the U.S. Government during 1948 to 1971, 22 have closed down either due to exhaustion of reserves or lack of market. On the inactive mill sites there remains 24 million metric tons of tailings containing 14,000 curies of radium. Success in stabilization has been variable. In the past, theoretical models have had to be used in estimation of the environmental effects of uranium milling for lack of a sufficient factual base. ERDA in cooperation with the Environmental Protection Agency and the states involved is undertaking a comprehensive radiological assessment at each site. The results of this assessment should provide valuable basic information on the environmental impact of uranium ore processing. The current studies reveal that the inactive sites are a cause of small public exposure to radiation, primarily from radon-222 from the tailings piles. This paper reviews radioactivity management in uranium ore processing to control spread of radioactive materials, including methods used for stabilization to prevent wind and water erosion. Recent measurements of radioactivity levels in soils, ground and surface waters, and in air near tailings piles are summarized, and public health implications are evaluated. Guidelines have been developed for land decontamination, and procedures evaluated for long-term management of contaminated material to minimize future human exposure. Alternative methods for long-term tailings stabilization, their costs and benefits in terms of serious health effects avoided are presented

Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

Science.gov (United States)

Henda, R; Hermas, A; Gedye, R; Islam, M R

2005-01-01

A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

Physico chemical characterization of mill tailings and speciation studies of uranium a Jaduguda, India

International Nuclear Information System (INIS)

Sarjan Singh; Jha, V.N.; Sethy, N.K.; Rout, S.; Ravi, P.M.; Jha, S.K.; Tripathi, R.M.

2018-01-01

After recovery of economically viable portion of the ore remaining solid slurry or tailings from uranium ore processing industry is discharged into an engineered system called tailings pond. Among the radio-nuclides quantitative content of residual uranium is highest in the tailings pond and various environmental interactions such as precipitation, change in pH, redox potential, microbial activities, organic associations has a potential to fix (precipitate) or solubilise it. The chemical fractionation of 'U' in mill tailings of both operational and non operational tailing ponds of Jaduguda uranium mining and ore processing site has been part of present study. Also, the role of various physicochemical parameters (pH, Eh, TC etc) on the mobility of uranium has been investigated

Influence of Copper Ore Comminution in HPGR on Downstream Minerallurgical Processes

Directory of Open Access Journals (Sweden)

Saramak D.

2017-09-01

Full Text Available Crushing processes taking place in high-pressure grinding rolls devices (HPGR are currently one of the most efficient methods of hard ore size reduction in terms of the energy consumption. The HPGR products are characterized by a fine particle size and the micro-cracks formation in individual particles, which appears in downstream grinding processes, decreasing their energy consumption. The purpose of the paper was to analyze the effectiveness of a ball mill grinding process and flotation operations depending on the changeable conditions of run of the HPGR crushing process. The research programme carried out included crushing tests in the laboratory scale HPGR device at various settings of the operating pressure volume and selected qualitative properties of the feed material (i.e. particle size distribution. On the basis of obtained results the models, defining the grinding process effectiveness as a function of changeable conditions of HPGR process run, were determined. Based on these models the optimal grinding time in a ball mill was specified which is, in turn, the basis for optimization of operation the technological comminution circuits for a given material type. The obtained results proved that the application of HPGR devices in given copper ore comminution circuit may improve the effectiveness of downstream grinding process what leads to improvement of the entire circuit work efficiency through decreasing the process energy consumption and enhancing the product size reduction.

Environmental nuclear-geophysical ore monitoring in mines of Corporation Kazakhmys PLC.

Science.gov (United States)

Yefimenko, Sergei; Yefimenko, Olga; Makarov, Dmitriy

2014-01-01

An environmental monitoring of ore composition in complex deposits of Kazakhstan (the Zhezkazgan, Kusmuryn, Artemjevsk, Kounrad, Taskura and Zhaman-Aibat deposits) is carried out using EDXRF spectrometers RPP-12, RLP-21 and RLP-21T. The monitoring of ore concentrates in Satpaev, Balkhashsk and Zhezkazgan processing plants and in Zhezkazgan copper smelter continues at present time. The monitoring suggests data on new promising elements and environmental pollutants in ores and new trends in distribution of bound elements in ores.

Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

International Nuclear Information System (INIS)

Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

2000-01-01

The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

The geological characteristics and forming conditions of granite type uranium-rich ore deposits

Energy Technology Data Exchange (ETDEWEB)

Tiangang, Li; Hangshou, Tong; Mingyue, Feng; Yuexiang, Li; Zhan, Xu [Beijing Research Inst. of Uranium Geology (China)

1993-03-01

The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage.

The geological characteristics and forming conditions of granite type uranium-rich ore deposits

International Nuclear Information System (INIS)

Li Tiangang; Tong Hangshou; Feng Mingyue; Li Yuexiang; Xu Zhan

1993-03-01

The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage

Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

Science.gov (United States)

Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

2014-02-01

This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

Uranium mill decommissioning - an update on the Edgemont experience

International Nuclear Information System (INIS)

Donovan, Th.K.; Chart, E.J.; Cummings, G.W.; Tappan, J.T.

1983-01-01

This paper describes the Edgemont Uranium Mill Decommissioning Project. An estimated 5.4 million tons of contaminated material including approximately 2.5 million tons of uranium mill tailings will be moved to a disposal site approved by the Nuclear Regulatory Commission (NRC). The decommissioning activities will be carried out by Silver King Mines, Inc., under a management services contract to the Tennessee Valley Authority. The primary advantages of the disposal site chosen are the short distance from the existing site and the approximately 650 feet of relatively dense impermeable shales above the shallowest known aquifer. Three large ore stockpiles containing about 100,000 pounds of uranium have been moved from the mill site to a proposed mine site. The decommissioning project will be carried out by using the existing labor force to the maximum extent possible thus preventing a population influx and the accompanying socioeconomic input to the city of Edgemont, SD

Decomposition of silica-alumina ores of Afghanistan by sulfuric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2016-01-01

Present article is devoted to decomposition of silica-alumina ores of Afghanistan by sulfuric acid. Physicochemical properties of initial silica-alumina ores were studied by means of X-ray phase, differential thermal and silicate analysis. The influence of temperature, process duration and acid concentration on extraction rate of valuable components was considered. The optimal conditions of decomposition of silica-alumina ores of Afghanistan by sulfuric acid were proposed.

Uranium mining and milling environmental studies. (Latest citations from the EI Compendex plus database). Published Search

International Nuclear Information System (INIS)

1993-08-01

The bibliography contains citations concerning environmental and social aspects of uranium mining, milling and ore treatment. Environmental and social aspects include air and water pollution, public health, occupational safety, land reclamation, and waste disposal. The citations refer to monitoring and control of contaminants, and environmental surveys and impact statements for specific areas in the vicinity of mining and ore treatment facilities. There are also references to health studies performed on miners and millworkers. (Contains 250 citations and includes a subject term index and title list.)

Behaviour of the pH adjustment, Ion exchange and concentrate precipitation stages in the acid leaching of uranium phosphate ores

International Nuclear Information System (INIS)

Estrada Aguilar, J.; Uriarte Hueda, A.

1962-01-01

The uranium recovery from acid leach solutions of uranium-phosphate ores has been studied. Relations have been found between the solution characteristics and the results obtained at different stages of the process. The following data can thus be predicted: solids to remove and uranium recovery in the pH adjustment stage, uranium capacity of the resin, more suitable eluating agent, elution velocity and uranium concentration in the eluate in the ion exchange stage, and composition of the concentrate produced by direct precipitation of the eluate in the concentrate precipitation stage. (Author) 8 refs

Design and construction of an impoundment for precious metal mill tailings

International Nuclear Information System (INIS)

Moldt, S.F.; Miller, R.G.; Johnson, K.

1985-01-01

An engineering study and design of impoundments for the disposal of mill tailings is presented. The site is located in central Nevada, and the mill will incorporate conventional flotation followed by a carbon-in-pulp cyanide process for extraction of gold from ore. Mill process waste will be generated as flotation tailings and cyanide residue. Permeable site soils and environmental considerations required the prevention of infiltration of cyanide residue leachate into the subgrade. Geochemical modeling of flotation tailings indicated the potential for high concentration of iron and nickel to be present in the flotation tailings leachate. On-site soils were optimized for use in construction of the separate flotation tailings and cyanide residue impoundments. Embankments were constructed on compacted on-site sandy gravels. The cyanide residue impoundment was designed using a four-layer liner, utilizing all on-site soils and chemical soil additives. The liner consists of a leachate collection system over a low-permeability layer, which in turn is underlain by a leak detection drainage blanket and a low permeability subliner. The geochemical modeling performed in the analysis indicated that placement of a thin layer of oxidized surface soils, high in soluble sulfates, on the bottom of the flotation tailings impoundment would be sufficient to react with tailings leachate and cause precipitation of ferric oxide and the associated removal of nickel, permitting flotation tailings leachate to dilute acceptably with natural groundwater

Comparison of Wet and Dry Grinding in Electromagnetic Mill

Directory of Open Access Journals (Sweden)

Szymon Ogonowski

2018-03-01

Full Text Available Comparison of dry and wet grinding process in an electromagnetic mill is presented in this paper. The research was conducted in a batch copper ore grinding. Batch mode allows for precise parametrization and constant repetitive conditions of the experiments. The following key aspects were tested: processing time, feed size, size of the grinding media, mass of the material and graining media, and density of the pulp. The particles size distribution of the product samples was analyzed in the laboratory after each experiment. The paper discusses the experimental results as well as the concept of dry and wet grinding and classification circuits for the electromagnetic mill. The main points of the discussion are the size reduction effectiveness and power consumption of the entire system.

Chapter 1. The characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan

International Nuclear Information System (INIS)

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

2015-01-01

Present article is devoted to characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan. The chemical composition of danburite ore of Ak-Arkhar Deposit was defined. The chemical composition of danburite ore concentrate of Ak-Arkhar Deposit was defined as well.

Radioactivity of Ore Sites of Lead, Zinc and Phosphate in Serbia

International Nuclear Information System (INIS)

Todorovic, D.; Jankovic, M.; Nikolic, J.; Kosutic, D.

2011-01-01

Natural resources such as ores contain radioactive nuclides at various concentrations. Therefore it is important to investigate the radioactivity in these resources as well as in the soil at the locations of ore deposits. For that reason we conducted preliminary measurements in the soil samples taken from the locations of lead and zinc ore deposits (Bosilegrad and Raska) and from the locations of phosphate ore deposits of phosphate (Bosilegrad). The activity concentrations of radionuclides in soil samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23 %). Results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U as well as the produced radionuclide 137Cs (from the Chernobyl accident). Ambient gamma radiation dose rate in ground level air was also measured. (author)

Recent technical changes in the treatment plants of Sismo for uranium ores

International Nuclear Information System (INIS)

Clappier, L.; Michel, P.

1983-01-01

The mills of the Ste. Industrielle des Minerais de l'Ouest (Simo) have undergone various reconstructions, consisting of the replacement of worn equipment, an extension of the capacity (from 600000 to 1100000 tonnes per year) and the introduction of new techniques which are described in the present article: endless belt filters; the grinding operations in a wet medium lead to a pulp which contains 1.11 m 3 of water per tonne of ore; the insulation of one endless-belt filter from the washing sector after leaching has permitted an increase of the solid concentration of the pulps; the recovery of uraniferous solutions includes generally a stage of concentration and of purification of the uranium in solution by ion exchange on a resin or liquid solvent substrate; instead of using them in parallel, the ''Eluex'' process utilizes them in series; the extraction by solvent is achieved with mixers and decanters and more recently with the ''pulsed column'' since 1981; the treatment of scum which hampers the liquid/liquid extraction has been planned in several ways; the latest solution adopted concerns the filtration under pressure; the drying of the concentrate has been effected for several years at ''l'Ecarpiere'' by atomization at the drying space on the belt [fr

Environmental assessment of remedial action at the Lowman Uranium Mill Tailings Site near Lowman, Idaho

International Nuclear Information System (INIS)

1991-01-01

This document assesses the environmental impacts of stabilization on site of the contaminated materials at the Lowman uranium mill tailings site. The Lowman site is 0.5 road mile northeast of the unincorporated village of Lowman, Idaho, and 73 road miles from Boise, Idaho. The Lowman site consists of piles of radioactive sands, an ore storage area, abandoned mill buildings, and windblown/waterborne contaminated areas. A total of 29.5 acres of land are contaminated and most of this land occurs within the 35-acre designated site boundary. The proposed action is to stabilize the tailings and other contaminated materials on the site. A radon barrier would be constructed over the consolidated residual radioactive materials and various erosion control measures would be implemented to ensure the long-term stability of the disposal cell. Radioactive constituents and other hazardous constituents were not detected in the groundwater beneath the Lowman site. The groundwater beneath the disposal cell would not become contaminated during or after remedial action so the maximum concentration limits or background concentrations for the contaminants listed in the draft EPA groundwater protection standards would be met at the point of compliance. No significant impacts were identified as a result of the proposed remedial action at the Lowman site

Application of neutron activation analysis to control P2O5 content in ore and ore concentrates of ''Apatit'' works

International Nuclear Information System (INIS)

Belyakov, M.A.; Terent'eV, Eh.P.; Frolov, V.A.

1982-01-01

A technique for a neutron activation rapid analysis of fluorine is described. A mean-square error of the analysis makes up 0,g3 per cent F. The investigation has been carried out and a close correlation has been established for the Hibine massif exploited apatite deposits on the basis of the neutron activation analysis of fluorine and chemical analysis of P 2 O 5 . Possibilities are shown of using the neutron activation analysis of P 2 O 5 in ores and certain ore con-- centrates of ''Apatit'' works from the radioactivity induced in fluorine. A mean-square error of the analysis makes up 0,35 per cent P 2 O 5

NDE investigation of the timber foundation in the historic Kennecott Mine Concentration Mill Building

Science.gov (United States)

James P. Wacker; Xiping Wang; Douglas R. Rammer; Bessie M. Woodward

2011-01-01

The U.S. National Park Service acquired the National Historic Copper Mine at Kennecott, Alaska, in 1998. There was uncertainty about the condition of the timber-cribbing foundation supporting the concentration mill, the largest building in the mine complex. A comprehensive on-site evaluation of the timber cribbing foundation was performed in summer 2009. The inspection...

Thorium content of a mineral ore from Morro do Ferro by fission track technique

International Nuclear Information System (INIS)

Oliveira, C.A.N. de.

1980-10-01

The feasibility to determine thorium concentrations by fission track technique in samples of mineral ore has been demonstrated. The literature registers only the application of the fission track technique to mineral ore in the case where the fissionable element is uranium. The technique was applied to determine the thorium concentration of an ore sample from Morro do Ferro, taking advantage of the high thorium to uranium ratio in that mineral. The sample analysed presented a thorium concentration of 2467 +- 400 mg Th/Kg ore. The so called wet method was adopted by using the Bayer made Makrofol KG 10μm thick, as the detector foil, immersed in the thorium solution. The technique is also useful to determine thorium concentrations in environmental samples because of the following aspects: high sensitivity; fast chemical separation of interfering elements; low cost; and operational simplicity. (Author) [pt

Uranium and thorium recovery in thorianite ore-preliminary results

Energy Technology Data Exchange (ETDEWEB)

Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

2011-07-01

This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

The genesis of ores

International Nuclear Information System (INIS)

Brimhall, G.

1991-01-01

Human history and technology have been shaped by metals. How did they become concentrated in minable deposits located so conveniently near the earth's surface? The author explains the mechanisms of fluid transport-by magma, water and even air and wind-responsible for the chemical and physical interactions that created bodies of metallic ores throughout geologic history. From their formation to their modification at the surface of the earth, ore deposits are geologically transitory and reflect dynamic processes within the earth as well as atmospheric and climatic influences on hydrologic systems. As highly reactive supracrustal systems, they then serve as geochemical sensors providing a powerful record and set of tracer elements for deducing the history, transport paths and forces operative in the crust

Contrasts between the environmental restoration challenges posed by uranium mining and milling in the United States and the former German Democratic Republic

International Nuclear Information System (INIS)

Nelson, R.A.; Chernoff, A.R.; Mager, D.; Goldammer, W.

1993-01-01

The former Soviet Union demands for uranium feed materials were primarily met by the East German Republic. A small area 200 km long and 50 km wide in the provinces of Saxony and Thuringia provided more than half of the uranium concentrate processed by the Soviet Union, and used for nuclear weapons development and power generation. With the majority of the ore processed in Germany of an average lower grade than a number of deposits found around the world, the mining and milling resulted in an enormous scale of surface disturbance and quantities of mill tailings concentrated in a relatively small densely populated geographical area. As a result of the re-unification of the two Germanies, all uranium extraction and processing activities were suddenly brought to a halt for economic reasons. The former soviet-East German corporation responsible for the uranium concentrate production was changed into a German state-operated company tasked with the facility decommissioning and environmental restoration. Code-named WISMUT (the German word for Bismuth) during the cold war, this organization was literally changed overnight from a self-sufficient, autonomously operating and state controlled effort into a public works, environmentally conscious corporation

Determination of concentration levels of arsenic, gold and antimony in particle-size fractions of gold ore using Neutron Activation Analysis

International Nuclear Information System (INIS)

Nyarku, M.

2009-02-01

Instrumental Neutron Activation Analysis (INAA) has been used to quantify the concentrations of arsenic, gold and antimony in particle-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd, was first fractionated into fourteen (14) particle-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 microns and grains >2000 microns were not considered for analysis. Results of the sieving were analysed with easysieve software. The < 36 microns sub fraction was found to be the optimum, hosting bulk of all three elements. For arsenic, the element was found to be highly concentrated in < 36 to +100 microns size fractions and erratically distributed from +150 microns fraction and above. For gold, in exception of the sub fraction <36 which had exceptionally high concentration, the element is distributed in all the size fractions but slightly 'plays out' in the +150 to +400 microns fractions. Antimony occurrence in the sample was relatively high in <36 microns size fraction followed by 600 - 800, 800 - 1000, 400 - 600 and 36 - 40 microns size fractions in that order. Gold content in the sample was far higher than that of arsenic and antimony. Gold concentration in the composite sample was in the range 564 - 8420 ppm. Arsenic levels were higher as compared to antimony. The range of arsenic concentration in the composite sample was 14.33 - 186.92 ppm. Antimony concentration was in the range 1.09 - 9.48 ppm. (au)

Chapter 1. General information about uranium. 1.3. Uranium ores

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

2012-01-01

The uranium ores were described. It was found that uranium ores and natural mineral formations containing uranium and its compounds, can be found in concentrations that are technically possible for industrial utilization and which are economically profitable. It was defined that oxidation levels of uranium minerals have an impact on their reprocessing technology and behavior in hydrometallurgical re partition. It was found that the chemical composition of ores has a decisive importance during selection of their reprocessing method.

X-ray radiometric separation of low-grade tin ores

Energy Technology Data Exchange (ETDEWEB)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-10-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

X-ray radiometric separation of low-grade tin ores

International Nuclear Information System (INIS)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-01-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

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

Directory of Open Access Journals (Sweden)

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.

Uranium accompanying recovery from copper ores

International Nuclear Information System (INIS)

Golynko, Z.Sh.; Laskorin, B.N.

1981-01-01

In the search for new raw material sources for nuclear power engineering a review of the technique of uranium accompaning recovery from copper ores reprocessing products in some countries is presented. In the USA a sorption method of uranium extraction by means of strongly basic ion exchange resins from solutions upon copper case- hardening with subsequent extraction from eluates by solutions of tertiary amines is realized. Elution is realized with sulphuric acid. In South Africa an extraction reprocessing of gravitational concentrate extracted from copper sulphide flotation tailings is organized. In India the uranium extraction from copper ores flotation enrichment tailings is organized on a commerical scale. Presented are data on the scale of uranium recovery, various conditions of its recovery as well as block diagrams of the processes. It is shown that copper ores become an additional source of uranium recovery [ru

36Cl production in situ, and groundwater transport in a uranium ore deposit

International Nuclear Information System (INIS)

Cornett, R.J.; Andrews, H.R.; Brown, R.M.; Chant, L.A.; Cramer, J.; Davies, W.G.; Greiner, B.F.; Imahori, Y.; Koslowsky, V.T.; McKay, J.W.; Milton, G.M.; Milton, J.D.C.

1992-01-01

The authors have used AMS to measure 36 Cl concentrations produced in situ in ore and in groundwater within the 1.3 billion year old Cigar Lake uranium ore deposit. 36 Cl concentrations are up to 300 times higher in the ore zone than in the surrounding aquifer. Based on 36 Cl ingrowth, the authors calculate the residence time of water within the ore zone to be 100,000 to 300,000 years. Since the geologic setting of this deposit is a very close natural analogue to a proposed nuclear fuel waste repository, this analysis demonstrates that natural geological barriers can effectively isolate mobile radionuclides from an open, regional groundwater flow system over millennia

Flotation study on scheelite ore of chitral khyber pakhtoonkhwa, pakistan

International Nuclear Information System (INIS)

Bhatti, M.A.; Kazmi, K.R.; Mehmood, R.; Akram, A.

2014-01-01

The beneficiation of a siliceous scheelite ore of Chitral, Khyber Pakhtoonkhwa, Pakistan, was investigated by flotation process to determine the optimum conditions for obtaining maximum grade and recovery of the scheelite concentrate. The variables studied were including pH and pulp density maintained during conditioning, type and quantity of reagents added, conditioning time and froth collecting time. The results achieved were plotted against the grade and recovery of the rougher concentrate. Several methods of cleaning rougher concentrate were attempted. An ore initially containing 0.34% WO/sub 3/ was upgraded into a final concentrate assaying 64.66% WO/sub 3/ with 70.36% recovery. The tungsten concentrate obtained meets the specifications required to produce ferrotungsten and tungsten chemicals. (author)

Scientific basis for risk assessment and management of uranium mill tailings

Energy Technology Data Exchange (ETDEWEB)

1986-01-01

A National Research Council study panel, convened by the Board on Radioactive Waste Management, has examined the scientific basis for risk assessment and management of uranium mill tailings and issued this final report containing a number of recommendations. Chapter 1 provides a brief introduction to the problem. Chapter 2 examines the processes of uranium extraction and the mechanisms by which radionuclides and toxic chemicals contained in the ore can enter the environment. Chapter 3 is devoted to a review of the evidence on health risks associated with radon and its decay products. Chapter 4 provides a consideration of conventional and possible new technical alternatives for tailings management. Chapter 5 explores a number of issues of comparative risk, provides a brief history of uranium mill tailings regulation, and concludes with a discussion of choices that must be made in mill tailing risk management. 211 refs., 30 figs., 27 tabs.

Scientific basis for risk assessment and management of uranium mill tailings

International Nuclear Information System (INIS)

1986-01-01

A National Research Council study panel, convened by the Board on Radioactive Waste Management, has examined the scientific basis for risk assessment and management of uranium mill tailings and issued this final report containing a number of recommendations. Chapter 1 provides a brief introduction to the problem. Chapter 2 examines the processes of uranium extraction and the mechanisms by which radionuclides and toxic chemicals contained in the ore can enter the environment. Chapter 3 is devoted to a review of the evidence on health risks associated with radon and its decay products. Chapter 4 provides a consideration of conventional and possible new technical alternatives for tailings management. Chapter 5 explores a number of issues of comparative risk, provides a brief history of uranium mill tailings regulation, and concludes with a discussion of choices that must be made in mill tailing risk management. 211 refs., 30 figs., 27 tabs

Current practices and options for confinement of uranium mill tailings

International Nuclear Information System (INIS)

1981-01-01

At the United Nations Conference on the Human Environment, which took place in Stockholm from 4 to 6 June 1972, national governments were asked to explore, with the International Atomic Energy Agency and other appropriate international organizations, international co-operation on radioactive waste matters including those of mining and tailings disposal. Since that time the IAEA has been active in the field of uranium and thorium mill tailings management. As part of this activity, the present report describes current practices and options for confinement of uranium mill tailings. It is addressed to technical and administrative personnel who are involved in planning and implementing national and industrial programmes on the management of such tailings. In 1974 and 1975 the IAEA convened meetings of experts to review matters of interest and importance in the management of uranium and thorium mine and mill tailings. These activities led to the publication in 1976 of Management of Wastes from the Mining and Milling of Uranium and Thorium Ores, a Code of Practice and Guide to the Code, IAEA Safety Series No. 44. As a continuation of this activity, the IAEA is here dealing more specifically with the design and siting considerations for the management of uranium mill tailings

Releases of radioactivity from uranium mills and effluent treatment costs

International Nuclear Information System (INIS)

Witherspoon, J.P.; Sears, M.B.; Blanco, R.E.

1977-01-01

Airborne releases of radioactive materials from uranium milling to the environment consist of ore dust, yellowcake dust, tailings dust, and radon gas while the mill is active. After a mill has ceased operations, tailings may be stabilized to minimize or prevent airborne releases of radioactive particulates. However, radon gas will continue to be released in amounts inversely proportional to the degree of stabilization treatment (and expense). Liquid waste disposal is by evaporation and natural seepage to the ground beneath the tailings impoundment area. The release of radioactive materials (and potential radiation exposures) determines the majority of costs associated with minimizing the environmental impact of uranium milling. Radwaste treatments to reduce estimated radiation doses to individuals to 3 to 5% of those received with current milling practices are equivalent to $0.66 per pounds of U 3 O 8 and 0.032 mill per kWhr of electricity. This cost would cover a high efficiency reverse jet bag filter and high energy venturi scrubbers for dusts, neutralization of liquids, and an asphalt-lined tailings basin with a clay core dam to reduce seepage. In addition, this increased cost would cover stabilization of tailings, after mill closure, with a 1-in. asphalt membrane topped by 2 ft of earth and 0.5 ft of crushed rock to provide protection against future leaching and wind erosion. The cost of reducing the radiological hazards associated with uranium milling to this degree would contribute about 0.4% to the current total cost of nuclear power

Radiation survey of dwellings in Cane Valley, Arizona and Utah, for use of uranium mill tailings. Final technical note

International Nuclear Information System (INIS)

Hans, J.M. Jr; Douglas, R.L.

1975-08-01

A radiation survey was conducted in the Cane Valley area of Monument Valley, on the Navajo Reservation, to identify dwellings in which uranium mill tailings had been used and to assess the resulting radiation exposures. Sixteen of the 37 dwellings surveyed were found to have tailings and/or uranium ore used in their construction. Tailings were used in concrete floors, exterior stucco, mortar for stone footings, cement floor patchings, and inside as cement 'plaster'. Uranium ore was found in footings, walls, and in one fireplace. Other structures, not used as dwellings, were also identified as having tailings and ore use. Gamma ray exposure rates were measured inside dwellings and structures identified as having tailings and/or ore used in their construction. Indoor radon progeny samples were collected in occupied dwellings where practical

Recovery of uranium from low-grade sandstone ores and phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R H [United States Atomic Energy Commission, Washington, D. C. (United States)

1967-06-15

This paper is concerned principally with commercial-scale experience in the United States in the recovery of uranium from low-grade sources. Most of these operations have been conducted by the operators of uranium mills as an alternative to processing normal-grade ores. The operations have been generally limited, therefore, to the treatment of low-grade materials generated in the course of mining normal-grade ores. In some circumstances such materials can be treated by simplified procedures as an attractive source of additional production. The experience gained in uranium recovery from phosphate rock will be treated in some detail. The land pebble phosphate rock of central Florida generally contains about 0.01 to 0.02% U{sub 3}O{sub 8}. While no uranium is being recovered from this source at the present time, it does represent a significant potential source of by-product uranium production because of the large tonnages being mined. (author)

Study of the dry processing of uranium ores

International Nuclear Information System (INIS)

Guillet, H.

1959-02-01

A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [fr

Tailings treatment techniques for uranium mill waste: a review of existing information

International Nuclear Information System (INIS)

Sherwood, D.R.; Serne, R.J.

1983-07-01

Of primary concern at uranium mill sites in the United States is the potential of ground-water contamination from mill wastes that are disposed in tailings impoundments. Although many systems have been used to control seepage from tailings impoundments, most of these systems are limited in their ability to handle an excess of tailings solution. Three general amelioration methods were identified: neutralization, fixation and specific constituent removal. During neutralization, a reagent is added to the tailings solution to neutralize the acidity and raise the pH to reduce the solubility of various pH sensitive contaminants. Fixation processes add materials such as lime, cement or asphalt to the waste to produce a physically stable composition that resists leaching of hazardous constituents. Specific constituent removal encompasses varying techniques, such as alternate ore leaching processes, effluent treatment with sorption, or ion exchange agents or selected precipitation that reduce specific constituent concentrations in tailings solution. Neutralization processes appear to be best suited for treating uranium mill tailings because they can, at a reasonable cost, limit the solution concentration of many contaminants. The effectiveness of the process depends on the reagent used as well as the waste being treated. Of the six reagents studied (lime, limestone, caustic soda, soda ash, combined limestone/lime and combined alumina/lime/soda), a combined treatment of limestone and lime seems best, especially for tailings containing ferric iron as the limestone economically buffers the solution acidity while the lime takes the pH to 8.0, an optimum level for heavy metal removal. For those tailings containing ferrous iron, lime alone works best. The costs for the lime/limestone or lime processes range from $0.20 to $1.00 per 1000 gal of treated water, excluding capital equipment costs

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.

Lead isotopes as indicators of environmental contamination from the uranium mining and milling industry in the Grants Mineral Belt, New Mexico

International Nuclear Information System (INIS)

Curtis, D.B.; Gancarz, A.J.

1978-01-01

The unique isotopic composition of lead from uranium ores can be useful in studying the impact of ore processing effluents on the environment. Common lead on the earth's surface is composed of 1.4% 204 Pb, 24.1% 206 Pb, 22.1% 207 Pb, and 52.4% 208 Pb. In contrast, lead associated with young uranium ores may contain as much as 95% 206 Pb. These extreme differences provide the means to quantitatively evaluate the amount of lead introduced into the environment from the mining and milling of uranium ores by measuring variations of the isotopic composition of lead in environmental samples. The use of Pb isotopes as diagnostic tools in studying the hydrologic transport of materials from U ore dressing plants in the Grants Mineral Belt, New Mexico, is discussed. Preliminary measurements on effluents intimately associated with processing wastes are consistent with a simple model in which radiogenic lead from the ores is mixed with common lead from the uncontaminated environments

Natural galvaniv effect when bed-oxidation ore-bearing zone forming

International Nuclear Information System (INIS)

Shchetochkin, V.N.; Kislyakov, Ya.M.; Vasil'eva, Eh.G.

1995-01-01

Hypothesis of the essential role of natural galvanic process in exogenetic-epigene ore-formation the model of which was elaborated earlier, is grounded. Genetic conjuction of variations near geochemical barrier of redox and acidic-alkaline hydrogeochemical parameters is stated. These variations in total enable to understand the mechanism of formation of infiltration uranium mineralizatiuon, to explain a number of the observed peculiarities of oxidation ore-controlling zoning, and to explain, as well, slightly-expressed concentration of elements-hydrolyzates in uranium ores. 29 refs.; 6 figs.; 3 tabs

Flux and concentration processes of radioactive elements in the forest industry; dosimetry, biofueled heating plants, the alkaline and the acidic pulp mill processes

International Nuclear Information System (INIS)

Ravila, A.; Holm, E.

1992-01-01

A fraction of the radionuclides released to the forest ecosystem will be incorporated into different parts of the trees and the wood. A common factor for both biofueled power plants and pulp mills is that they concentrate the radionuclides initially present in the in the biofuel or wood in ashes or other products. The enrichment of radioactive elements is due to the combustion process or in a pulp mill, the combustion of bark and liquors, and also the processes in the pulp mill recycling system. The radiological impacts to man from forest industry arises form radiation emitted from the radionuclides present in ash and pulp mill liquors and liquor sludge. The quantification and calculation of past, present and future activity concentrations in biofuels, ash and pulp mill waste products are all important when assessments of the radiation dose is done. In order to assess the resulting dose to staff working close to radionuclide containing recycling systems and waste dumps, it is necessary to know the dynamics (inflow rate and residence time) of the radionuclides in that system

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.

Studies of leaching of copper ores and flotation wastes

International Nuclear Information System (INIS)

Wawszczak, D.; Deptula, A.; Lada, W.; Smolinski, T.; Olczak, T.; Brykala, M.; Wojtowicz, P.; Rogowski, M.; Milkowska, M.; Chmielewski, A.G.

2014-01-01

In Poland, there are significant deposits of copper ores. During the copper extraction, large amounts of flotation wastes are produced. In the ores and flotation wastes many other important elements are present. The main goal of this work was analysis of uranium content and to elaborate procedures for recovery of U from these materials. Two types of ores and four types of waste were examined. It has been found that uranium content varies from 4.5 to 25 ppm. The other elements have also been determined in these materials: Cu (4-5 % in ores and 0.3-1.7 % in waste), Ag, Re, Mo, La, Ni, V, etc. For leaching, sulfuric acid and sodium carbonates of various concentrations (temperature, time) were used. The optimum conditions for leaching have been found. The concentration of uranium in the final solution was generally less than 25 μg/mL. The other elements are also present in the leaching solutions. Simultaneous liquid-liquid extraction of uranium with these elements from leaching solution is under study. In our opinion, only such combined procedure for the recovery of uranium together with the accompanying elements could be cost-effective. (author)

Decommissioning of the Zirovski Vrh Uranium Mill

International Nuclear Information System (INIS)

Zabukovec, I.; Logar, Z.; Arh, S.

1996-01-01

First of the inventions, which will ensure the beginning of the permanent closure of uranium ore exploitation and prevent the consequences of mining in the Zirovski Vrh Uranium Mine, abandoned according to the law from July 1992, will be soon realized. After obtaining the location permit for dismantling the equipment, foundations and installations in four main buildings of the uranium mill, current procedures are carried out in order to obtain the permission for performing the mentioned activities and to make contracts with acting organizations. Those buildings contain sources of radiation, which were considered within the legal procedures and design of technical documentation. Instructions for decontamination and protection against radiation, both issued with those projects, highly contribute to the Slovenian experience in the field of practical management of radiation sources. Additional requirement, which enters difference between decommissioning of similar mills worldwide and the one mentioned, is preservation of buildings in order to change their purpose. (author)

The Effect of Fe Concentration on the Quality and Quantity of Biogas Produced From Fermentation of Palm Oil Mill Effluent

Directory of Open Access Journals (Sweden)

Irvan Matseh

2012-10-01

Full Text Available The purpose of this research is to study the effect of Fe concentration as a trace metal on the quality and quantity of biogas produced from the fermentation of palm oil mill effluent (POME. Raw POME as feed was obtained from one of the palm oil mills belong to PTPN IV, other materials used were hydrochloric acid, sodium bicarbonate, and trace metals. Observed variables were volume of biogas, concentration of Fe in raw POME and biodigester, degradation rate of total solid (TS and volatile solid (VS, M-Alkalinity, pH, H2S and CO2 concentration in biogas at hydraulic retention time (HRT 6 days. Before HRT of 6 days reached, initial trace metal compositions were 25.2 mg/L of Fe, 0.42 mg/L of Co, and 0.49 mg/L of Ni. After that, composition of trace metal were consisted only Co and Ni. The results showed that Fe as a trace metal did not affect the production or quantity of biogas. When Fe concentration reached over to 330 mg/L then concentration of CH4, total solid (TS and volatile solid (VS decreased. Moreover, the higher the Fe contents the smaller of H2S production. Fe content in POME from the same mill had different concentration, as the consequence biogas with different H2S concentrations were produced as well. Thus, Fe in the trace metals is no longer required if high concentration of Fe already existed in POME because it can reduce the formation of H2S. In addition, too high concentration of Fe in POME can be toxic for microorganism in the fermentation of biogas.

Ore-concentrating structures with telescoped uranium mineralization

International Nuclear Information System (INIS)

Shchetochkin, V.N.; Dmitriyev, V.I.; Tkachenko, I.I.

1986-01-01

Deep faults are the main controlling elements in uranium ore fields, although the immediate geologic environments may be quite varied. Within the fault zones, the uranium fields are usually associated with areas where major transverse and diagonal faults intersect or link, and with points of splitting or change in strike in disjunctive zones. Another distinctive feature of the mineralized structure is their long history, with a combination of tectonic elements differing in age and type, usually associated with retrograde dislocation metamorphism. The specific features of these structures control the uranium mineralization, which is usually localized in foci with telescoped tectonic, magmatic, hydrothermal, metasomatic, and sometimes exogenous processes. The unnamed area (in the Ukraine?) furnishes a good example of how successive stages of a complex geologic history affect the occurrence of such a highly mobile element as uranium. 12 references, 4 figures

Uranium extraction from ores with salicylic acid; I - uranium extraction from input phosphate ore of Abu Zaabal phosphate plant, Egypt

International Nuclear Information System (INIS)

Hussein, E.M.

1997-01-01

Salicylic acid has been tested (for environmental importance) to extract U from input phosphate ore of Abu-Zaabal phosphate plant, Egypt prior to its processing for production of phosphatic fertilizers. Uranyl ion forms with this acid three stable complexes; namely [UO 2 Sal] degree, [U O 2 SaL 2 ] 2- and UO 2 SaL-3] 4- depending on the total uranyl and salicylic acid concentrations and their ratios. Study of relevant extraction factors revealed however that, the extraction process is controlled by the amount of salicylic acid used, alcohol/aqueous ratio, solid/liquid ratio and time of agitation. The obtained results showed that uranium is selectively leached by the application of such a leaching reagent. In order to recover U from the obtained pregnant leach liquor, the latter is adjusted by ammonia to PH 5-6.5, where the crystalline pp t of N H 4 [UO 2 SaL 3 ] 4 H 2 O has formed. This precipitation has been carried out after concentrating the obtained pregnant leach liquor by its recycle for U extraction from new ore batches. The precipitated ammonium uranyl tri salicylate is calcined at 500 degree C for obtaining pure orange yellow trioxide (UO 3 ) powder. On the basis of one ton ore treatment, an economic flowsheet for U recover y from the study ore material has been suggested

Application of X-ray luminescence separation to preliminary enrichment of lean scheelite-containing ores

International Nuclear Information System (INIS)

Zhaboev, M.N.; Semochkin, G.A.; Blinov, Yu.I.; Dzhambaev, F.M.; Novikov, V.V.; Tereshchenko, S.V.

1987-01-01

Investigations of preliminary enrichment of lean ores of amphibole hornfels by the method of X-ray luminescence separation was conducted. Pile and enriched products with different WO 3 content were obtained from these ores; WO 3 content in pile products was 2-2.5 times lower as compared to factory tailing products. WO 3 content in separator concentrate corresponds in all cases to the requirements for the ore designated for flotation enrichment. Carbonate modulus decreases 2.5-4 times in separation concentrate, simplifying the conditions of flotation

Method and apparatus for measuring the concentration of water, iron, and aluminum in iron ore by neutron radiation

International Nuclear Information System (INIS)

Holmes, R.J.; Wylie, A.W.; McCracken, K.G.

1975-01-01

Techniques and apparatus for measuring the concentration of water and specific components in materials are described. The techniques involve irradiating the material with neutrons and monitoring the neutron flux in the vicinity of the irradiated material and the gamma radiation from excited nuclei of the specific component. Examples of the use of the invention include on-stream monitoring of ores carried by conveyor belts and borehole logging using a probe which carries a neutron source, and neutron and gamma radiation detectors. (U.S.)

Analytical fingerprint for tantalum ores from African deposits

Science.gov (United States)

Melcher, F.; Graupner, T.; Sitnikova, M.; Oberthür, T.; Henjes-Kunst, F.; Gäbler, E.; Rantitsch, G.

2009-04-01

Illegal mining of gold, diamonds, copper, cobalt and, in the last decade, "coltan" has fuelled ongoing armed conflicts and civil war in a number of African countries. Following the United Nations initiative to fingerprint the origin of conflict materials and to develop a traceability system, our working group is investigating "coltan" (i.e. columbite-tantalite) mineralization especially in Africa, also within the wider framework of establishing certified trading chains (CTC). Special attention is directed towards samples from the main Ta-Nb-Sn provinces in Africa: DR Congo, Rwanda, Mozambique, Ethiopia, Egypt and Namibia. The following factors are taken into consideration in a methodological approach capable of distinguishing the origin of tantalum ores and concentrates with the utmost probability: (1) Quality and composition of coltan concentrates vary considerably. (2) Mineralogical and chemical compositions of Ta-Nb ores are extremely complex due to the wide range of the columbite-tantalite solid solution series and its ability to incorporate many additional elements. (3) Coltan concentrates may contain a number of other tantalum-bearing minerals besides columbite-tantalite. In our approach, coltan concentrates are analyzed in a step-by-step mode. State-of-the-art analytical tools employed are automated scanning electron microscopy (Mineral Liberation Analysis; MLA), electron microprobe analysis (major and trace elements), laser ablation-ICP-MS (trace elements, isotopes), and TIMS (U-Pb dating). Mineral assemblages in the ore concentrates, major and trace element concentration patterns, and zoning characteristics in the different pegmatites from Africa distinctly differ from each other. Chondrite-normalized REE distribution patterns vary significantly between columbite, tantalite, and microlite, and also relative to major element compositions of columbites. Some locations are characterized by low REE concentrations, others are highly enriched. Samples with

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)

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.

Moessbauer study of the chemical state of gold in gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

1986-01-01

Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

Overview of uranium mill tailings remedial action project of the United States of America 1995-1996

International Nuclear Information System (INIS)

Edge, R.

1997-01-01

From the early 1940's through the 1960's the United States federal government contracted for processed uranium ore for national defense research, weapons development and commercial nuclear energy. When these contracts were terminated, the mills ceased operation leaving large uranium tailings on the former mill sites. The purpose of the Uranium Remedial Action Project (UMTRA) is to minimize or eliminate potential health hazards resulting from exposure of the public to the tailings at these abandons sites. There are 24 inactive uranium mill tailings sites, in 10 states and an Indian reservation lands, included for clean up under the auspices of UMTRA. Presently the last 2 sites are under remediation. This paper addresses the progress of the project over the last two years. (author)

Problems of developing remedial strategy for the uranium ore processing legacy site Pridneprovsky Chemical Plant site (Dneprodzerginsk, Ukraine)

International Nuclear Information System (INIS)

Riazantsev, V.; Bugai, D.; Skalskyy, A.; Tkachenko, E.

2014-01-01

In this paper we present results of works and studies carried out in the frame of ongoing national and international projects aimed at developing the remedial strategy for the Soviet era legacy uranium production site Pridneprovsky Chemical Plant, Dneprodzerginsk, Ukraine. The site includes several uranium mill tailings, contaminated buildings, ore storage grounds and other contaminated facilities. Taking into account the necessity to implement provisions of the new IAEA standards (Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, No. GSR Part 3 (Interim) and others) as well as the provisions of the ICRP 103 publication, the State Nuclear Regulatory Inspectorate Ukraine developed the draft of the new licensing requirements for activities of uranium ores processing.

Manual on laboratory testing for uranium ore processing

International Nuclear Information System (INIS)

1990-01-01

Laboratory testing of uranium ores is an essential step in the economic evaluation of uranium occurrences and in the development of a project for the production of uranium concentrates. Although these tests represent only a small proportion of the total cost of a project, their proper planning, execution and interpretation are of crucial importance. The main purposes of this manual are to discuss the objectives of metallurgical laboratory ore testing, to show the specific role of these tests in the development of a project, and to provide practical instructions for performing the tests and for interpreting their results. Guidelines on the design of a metallurgical laboratory, on the equipment required to perform the tests and on laboratory safety are also given. This manual is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Management. A report on the Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores (Technical Reports Series No. 196, 1980) and an instruction manual on Methods for the Estimation of Uranium Ore Reserves (No. 255, 1985) have already been published. 17 refs, 40 figs, 17 tabs

US Geological Survey research on the environmental fate of uranium mining and milling wastes

International Nuclear Information System (INIS)

Landa, E.R.; Gray, J.R.

1995-01-01

Studies by the US Geological Survey (USGS) of uranium mill tailings (UMT) have focused on characterizing the forms in which radionuclides are retained and identifying factors influencing the release of radionuclides to air and water. Selective extraction studies and studies of radionuclide sorption by and reaching from components of UMT showed alkaline earth sulfate and hydrous ferric oxides to be important hosts of radium-226 ( 226 Ra) in UMT. Extrapolating from studies of barite dissolution in anerobic lake sediments, the leaching of 226 Ra from UMT by sulfate-reducing bacteria was investigated; a marked increase in 226 Ra release to aqueous solution as compared to sterile controls was demonstrated. A similar action of iron(III)-reducing bacteria was later shown. Ion exchangers such as clay minerals can also promote the dissolution of host-phase minerals and thereby influence the fate of radionuclides such as 226 Ra. Radon release studies examined particle size and ore composition as variables. Aggregation of UMT particles was shown to mask the higher emanating fraction of finer particles. Studies of various ores and ore components showed that UMT cannot be assumed to have the same radon-release characteristics as their precursor ores, nor can 226 Ra retained by various substrates be assumed to emanate the same fraction of radon. Over the last decade, USGS research directed at offsite mobility of radionuclides form uranium mining and milling processes has focused on six areas: the Midnite Mine in Washington; Ralston Creek and Reservoir, Colorado; sites near Canon City, Colorado; the Monument Valley District of Arizona and Utah; the Cameron District of Arizona; and the Puerco River basin of Arizona and New Mexico. 48 refs., 6 figs., 4 tabs

Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen

Science.gov (United States)

Elliott, R.; Pickles, C. A.

2017-09-01

Nickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673-873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

Estimated water requirements for the conventional flotation of copper ores

Science.gov (United States)

Bleiwas, Donald I.

2012-01-01

This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

The effect of exposure to employees from mining and milling operations in a uranium mine on lead isotopes--a pilot study.

Science.gov (United States)

Gulson, Brian L; Mizon, Karen J; Dickson, Bruce L; Korsch, Michael J

2005-03-01

Potential exposure during mining and milling of uranium ore has resulted in the industry being highly regulated. Exposure can arise from inhalation of the daughter product radioactive gas radon (222Rn), inhalation of radioactive dust particles from mining and milling, direct irradiation from outside the body, and ingestion of radionuclides (e.g. uranium or radium) in food or water. Making use of the highly unusual lead isotopic signature for uranium ores (high 206Pb/204Pb from the high uranium content, low 208Pb/204Pb from the low Th/U ratio), we undertook a pilot study of nine male mine employees and three controls from the Ranger uranium mine in the Northern Territory Australia to determine if it was feasible to use lead isotopes in blood to identify exposure to uranium-derived materials. The lead isotopic data for the mine employees and controls plot in two distinct fields which are consistent with predicted isotopic patterns. Assuming retention of 10% of the ingested lead, then the increases seen in 206Pb represent intakes of between 0.9 and 15 mg, integrated over the years of exposure. The small amount of lead does not affect blood lead concentrations, but appears to be sufficient to be detectable with sensitive isotopic methods. Further studies, including those on urine, should be undertaken to confirm the veracity of the lead isotope method in monitoring exposure of uranium industry employees.

The effect of exposure to employees from mining and milling operations in a uranium mine on lead isotopes. A pilot study

International Nuclear Information System (INIS)

Gulson, Brian L.; Mizon, Karen J.; Dickson, Bruce L.; Korsch, Michael J.

2005-01-01

Potential exposure during mining and milling of uranium ore has resulted in the industry being highly regulated. Exposure can arise from inhalation of the daughter product radioactive gas radon ( 222 Rn), inhalation of radioactive dust particles from mining and milling, direct irradiation from outside the body, and ingestion of radionuclides (e.g. uranium or radium) in food or water. Making use of the highly unusual lead isotopic signature for uranium ores (high 206 Pb/ 204 Pb from the high uranium content, low 208 Pb/ 204 Pb from the low Th/U ratio), we undertook a pilot study of nine male mine employees and three controls from the Ranger uranium mine in the Northern Territory Australia to determine if it was feasible to use lead isotopes in blood to identify exposure to uranium-derived materials. The lead isotopic data for the mine employees and controls plot in two distinct fields which are consistent with predicted isotopic patterns. Assuming retention of 10% of the ingested lead, then the increases seen in 206 Pb represent intakes of between 0.9 and 15 mg, integrated over the years of exposure. The small amount of lead does not affect blood lead concentrations, but appears to be sufficient to be detectable with sensitive isotopic methods. Further studies, including those on urine, should be undertaken to confirm the veracity of the lead isotope method in monitoring exposure of uranium industry employees

Report on the progress of work in Portugal [Processing of Low-Grade Uranium Ores]; Rapport sur l'etat d'avancement des travaux au Portugal

Energy Technology Data Exchange (ETDEWEB)

Carreira Pich, H [Junta de Energia Nuclear, Laboratorio de Fisica e Engenharia Nucleares, Sacavem (Portugal)

1967-06-15

The purpose of the principal studies until now in Portugal were the development of two types of treatment of the uranium minerals: - Traditional leaching by agitation of the ore milled in a finely sulphuric acid solution; - Leaching of the type 'heap leaching' in which the ore is hard crushed, and then sprinkles is crammed with sulphuric acid solution. Leaching tests were performed traditionally with samples of available Portuguese minerals. In most cases, the dissolution of uranium is easy and low consumption of acid. Efforts were oriented in the direction of a leaching type 'heap leaching'.

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

Architecture and environmental restoration: Remediating uranium mill tailings from buildings

International Nuclear Information System (INIS)

Teply, J.D.

1991-01-01

The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) manages the Uranium Mill Tailings Remedial Action (UMTRA) Program in Grand Junction, Colorado. This program is a congressionally mandated clean up of by-product waste that resulted from the extraction of yellow cake from uranium ore. The by-product waste, a fine sand commonly called open-quotes mill tailingclose quotes is contaminated with low-level radioactivity. These mill tailings were available to the community for use as construction material from approximately 1952 to 1966; their use as bedding material for concrete slabs, utilities, backfill materials, concrete sand, and mortar created unique remediation problems that required innovative solutions. This paper describes how design personnel approach the remediation of structures, the evaluation of the buildings, and the factors that must be considered in completing the remediation design. This paper will not address the health risks of the tailings in an inhabited space, the remediation of exterior areas, or the process of determining where the tailings exist in the building

Recycling and disposal of FUSRAP materials from the Ashland 2 site at a licensed uranium mill

International Nuclear Information System (INIS)

Howard, B.; Conboy, D.; Rehmann, M.; Roberts, H.

1999-01-01

During World War II the Manhattan Engineering District (MED) used facilities near Buffalo, N.Y. to extract natural uranium from ores. Some of the byproduct material left from the ores (MED byproduct), containing low levels of uranium, thorium, and radium, was deposited on a disposal site known as Ashland 2, located in Tonawanda, NY. On behalf of the United States Army Corps of Engineers (USACE, or the Corps), ICF Kaiser Engineers (ICFKE) was tasked to provide the best value clean-up results that meet all of the criteria established in the Record of Decision for the site. International Uranium (USA) Corporation (IUC), the operator of the White Mesa Uranium Mill, a Nuclear Regulatory Commission (NRC)-licensed mill near Blanding, Utah, was selected to perform uranium extraction on the excavated materials, therefore giving the best value as it provided beneficial use of the material consistent with the Resource Conservation and Recovery Act (RCRA) intent to encourage recycling and recovery, while also providing the most cost-effective means of disposal. Challenges overcome to complete this project included (1) identifying the best-value location to accept the material; (2) meeting regulatory requirements with IUC obtaining an NRC license amendment to accept and process the material as an alternate feed; (3) excavating and preparing the material for shipment, then shipping the material to the Mill for uranium recovery; and (4) processing the material, followed by disposal of tailings from the process in the Mill's licensed uranium tailings facility. Excavation from Ashland 2 and processing of the Ashland 2 material at the White Mesa Mill resulted in a cleaner environment at Tonawanda, a cost avoidance of up to $16 million, beneficial recovery of source material, and environmentally protective disposal of byproduct material. (author)

Geochemical behavior of uranium mill tailings leachate in the subsurface

International Nuclear Information System (INIS)

Brookins, D.G.

1993-01-01

Leachate generated from surface disposal of acidic uranium mill tailings at Maybell, CO has impacted groundwater quality within the underlying mineralized Browns Park Formation. The extent of groundwater contamination, however, is located directly beneath the tailings impoundment. The milling process consisted of sulfuric acid extraction of uranium from the feed ore by a complex chemical leaching and precipitation process. Tailings leachate at the site contains elevated concentrations of Al, As, Cd, Mo, Ni, NO 3 , Se, U, and other solutes. From column leach tests, the concentrations of contaminants within tailings pore fluid are SO 4 >NH 4 >NO 3 >U>Se>Ni>As>Cd at pH 4.0. The carbonate buffering capacity of the tailings subsoil has decreased because of calcite dissolution in the presence of acidic leachate. Groundwater quality data, mineralogical and microbiological studies, and geochemical modeling suggest that As, NO 3 , Se, U and other solutes are being removed from solution through precipitation, adsorption, and denitrification processes under reducing conditions. Presence of hydrogen sulfide, liquid and gaseous hydrocarbons, dissolved organic, and abundant pyrite within the Browns Park Formations have maintained reducing conditions subjacent to the tailings impoundment. Groundwater is in close equilibrium with coffinite and uraninite, the primary U(IV) minerals extracted from the Browns Parks Formation. Denitrifying bacteria identified in this study catalyze redox reactions involving NO 3 . Subsequently, contaminant distributions of NO 3 decrease 1000 times beneath the tailings impoundment. Applying geochemical and biochemical processes occurring at Maybell provides an excellent model for in situ aquifer restoration programs considered at other uranium tailings and heavy-metal-mixed waste contaminated sites. (author) 4 figs., 4 tabs., 27 refs

Flotation of uranium from uranium ores in Canada. Part 2

International Nuclear Information System (INIS)

Muthuswami, S.V.; Vijayan, S.; Woods, D.R.

1985-01-01

Measurements are reported for the equilibrium of cupferron from solutions by uranium oxide, quartz, illite, a mixture of these three, pitchblende, pyrite and brannerite ore. The cupferron concentration ranged from 1 to 6 g/L, and the pH was 7 and 8. Most isotherms followed the Langmuir model, although Freundlich behaviour was observed for illite and pitchblende. Most adsorption was pH independent except for illite and pitchblende. The adsorption isotherms for a mixture of uranium oxide, quartz and illite in the same proportions as in the naturally occurring ore agreed with the adsorption of the pyrite-free ore at pH 8 but not pH 7. We attribute the discrepancy to the use of illite as the model clay. The specific adsorption of cupferron on quartz and illite is lower by a factor of about 50 and 5, respectively, than the adsorption on uranium oxide. Specific adsorption less than 1 mg cupferron per gm of pyrite free ore does not float the mineral. The corresponding equilibrium concentration of cupferron is 0.5 g/L. A qualitative model is given, and the implications of this work for practical operations are presented

Improving mine-mill water network design by reducing water and energy requirements

Energy Technology Data Exchange (ETDEWEB)

Gunson, A.J.; Klein, B.; Veiga, M. [British Columbia Univ., Vancouver, BC (Canada). Norman B. Keevil Inst. of Mining Engineering

2010-07-01

Mining is an energy-intensive industry, and most processing mills use wet processes to separate minerals from ore. This paper discussed water reduction, reuse and recycling options for a mining and mill operation network. A mine water network design was then proposed in order to identify and reduce water and system energy requirements. This included (1) a description of site water balance, (2) a description of potential water sources, (3) a description of water consumers, (4) the construction of energy requirement matrices, and (5) the use of linear programming to reduce energy requirements. The design was used to determine a site water balance as well as to specify major water consumers during mining and mill processes. Potential water supply combinations, water metering technologies, and recycling options were evaluated in order to identify the most efficient energy and water use combinations. The method was used to highlight potential energy savings from the integration of heating and cooling systems with plant water systems. 43 refs., 4 tabs., 3 figs.

An assessment of the long term suitability of present and proposed methods for the management of uranium mill tailings

International Nuclear Information System (INIS)

1979-07-01

Proposals for safe, long-term containment of conventional tailings include 1) storage under water, 2) storage in active, abandoned or specially created underground mines and, 3) storage in open pits, with subsequent flooding or covering with overburden. The underwater proposal can meet most of the requirements of long term containment; however, extensive study of existing tailings deposits in deep water locations will be needed. Underground mines cannot provide sufficient storage capacity, since the tailings bulk during mill operation can occupy twice the volume of the original ore. It is possible to reduce the hazard by reducing the radium and thorium content of the tailings. Proposals for such an undertaking include ore beneficiation with rejection of the relatively innocuous fraction, radium-thorium removal in the mill, and significant changes in both ore processing and treatment of tailings. It is concluded that surface-stored tailings are vulnerable over the long term to dispersion by leaching and water erosion, and that access to a tailings site cannot be prevented, while only a major climatic or seismic event could disturb tailings stored in suitable underwater or underground mine sites. The criteria for determining suitability for each method, however, will need to be identified, tested, and accepted through the normal process of modeling, pilot plant evaluation, monitoring and evaluation. (author)

Investigation of ore processing to recover uranium concentrate from sandstone of Pa Lua area on scale of 2 tons of ore per batch

International Nuclear Information System (INIS)

Cao Hung Thai; Dinh Manh Thang; Tran Van Son; Le Quang Thai; Bui Dang Hanh; Hoang Bich Ngoc; Nguyen Hong Ha; Phung Vu Phong; Nguyen Khac Tuan

2003-01-01

Based on the laboratory results, a system for testing on scale of 2 tons uranium ore per batch including following parts was established: equipment for crushing and grinding, equipment for acid leaching, equipment for impurity precipitation and filtration and drying. the results of testing by 2 tons ore per batch scale shown that uranium recovery in the leach circuit were achieved of at least 90% under following conditions: The supplying rate of leach agent 50-701/m 2 .h, sandstone is mixed or incubated with acid before the percolation. About 23 kg filter cake per m 3 solution were disposed as tailings. Flocculants N101, A101 (TOAGOSEL, Japan) were used for improvement of filtration and washing capacity of impurity precipitation. Uranium peroxide was precipitated with addition of hydrogen peroxide. The underflow solids were filtered and calcined. The product contained min. 76% U 3 O 8 . The water recycle was successfully tested. That results in minimization of water addition to only 0.3m 3 /ton of ore. Experimental results on 2 tons scale showed that the proposed processing flow sheet using direct precipitation can meet all environmental and technical objectives. (CHT)

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

Improvements on heap leaching process for a refractory uranium ore and yellow cake precipitation process

International Nuclear Information System (INIS)

Feng Jianke

2013-01-01

Some problems such as formed harden matrix, ore heap compaction, poor permeability, and agglomeration of absorption resin occur during extracting uranium from a refractory uranium ore by heap leaching process. After some measures were taken, i.e. spraying a new ore heap by low concentration acid, two or more ore heaps in series leaching, turning ores in ore heap, the permeability was improved, acid consumption was reduced. Through precipitate circulation and aging, the yellow cake slurry in amorphous or microlite form was transformed to crystal precipitate, thus uranium content in yellow cake was improved, and water content in yellow cake was lowered with good economic benefits. (author)

Status Report from Sweden [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Peterson, A [AB Atomenergi, Stockholm (Sweden)

1967-06-15

The Ministry of Education was authorized in November 1945 to appoint a commission to study the organization of nuclear energy research. In April 1947 this commission, the Swedish Atomic Energy Commission, proposed the formation of a semi-state-owned company to be a central body for applied research work and development in the nuclear energy field in Sweden. In November 1947 the Atomic Energy Company (AB Atomenergi) had its statutory meeting. The State owns 4/7 of the share capital and the remaining 3/7 is owned by 71 private and municipal share-holders. Except for a part of the stock capital, all investments and running costs of the company have been financed by the Government. The company is in practice answerable to the Department of Commerce which has an advisory body, the Atomic Energy Board. AB Atomenergi is responsible for Government-financed research on the industrial applications of nuclear energy, the milling of uranium ores and refining of uranium. The total number of employees is at present about 1400, 800 of which work at the company's research establishment Studsvik about 120 km south of Stockholm. As early as 1945 the Research Institute of the Swedish National Defence started work in the field of uranium processing. Similar work was also started quite early by the Boliden Mining Company, the Swedish Shale Oil Company and Wargons AB. After the establishment of AB Atomenergi, all work in the uranium processing field was transferred to this company. In fact one of the main reasons for the formation of AB Atomenergi was the need for Swedish uranium production as there was no possibility of importing uranium at that time. As a result of research and development in uranium processing a pilot plant at Kvarntorp near Orebro in central Sweden started milling a low-grade uranium ore (shale) in 1953. The capacity of this plant was 5-10 tons of uranium a year. A uranium mill at Ranstad in south-west Sweden, near Skovde, with a capacity of 120 tons of uranium a

Chemical treatment of uranium ores in France

International Nuclear Information System (INIS)

Mouret, P.; Sartorius, R.

1958-01-01

The various processes of chemical treatment of uranium ores, from the oldest to the more recent, are exposed, considering the following conditions: economics, geography, techniques and safety. The interest of obtaining a final concentrate as uranyl nitrate is discussed. (author) [fr

The critical importance of pulp concentration on the flotation of galena from a low grade lead–zinc ore

Directory of Open Access Journals (Sweden)

Xianping Luo

2016-04-01

Full Text Available The Qixia orebody is a complex lead–zinc sulfide system with pyrite gangue and minor amounts of copper. In order to improve the flotation results, laboratory scale flotation testing of ore samples taken from this operation was performed. Flotation tests used a sequential recovery protocol for selective flotation of first the lead and thereafter the zinc. The key parameters that influence flotation performance of lead mineral were tested in this paper. The test data show that, for comparable collector, grinding time, flotation pH and solid-in-pulp concentration, the increase of solid-in-pulp concentration has the most significant effect on the recovery and selective separation of lead mineral. The increase of solid-in-pulp concentration from 27% to 55% makes the recovery of lead mineral increased from 60% to 80% and the lead grade increased from 27.5% to 29.1%.

The fines recovery of the phosphoro-uraniferous ores from Itataia-CE

International Nuclear Information System (INIS)

Furtado, J.R.V.

1985-01-01

Cyclone desliming previous to flotation is one of the determining factors of the concentration performance of phosfate ores. The physical beneficiation of the phosphoro uraniferous ore of Itataia, carried out in the pilot plant, rejects approximately 10,5% P 2 O 5 and 14% U 3 O 8 contained as ''slimes''. The present investigation was to develop a process to recover the fines through the tecniques of flotation and Seletive Floculation. The low P 2 O 5 content and extremely small size of the ''slimes'', led to a low efficiency in the operation of either flotation. The introduction of a Second disliming step swhed promising results. It is work mentioning that the ore presents siliceous-carbonatic gangue and that the direct flotation of phosphates rejects only the silicate portion. Direct flotation followed by reverse flotation of carbonates led to phosphate concentrates containing 28% P 2 O 5 with recoveries of 60%. The results obtained indicate that the fines treatment may lead to increase of 4,5% in overall recovery without decreasing the grade of the final concentrate. (C.D.G.) [pt

Production of titanium silicate compositions from technogenic titanium containing waste of Khibiny ores' enrichment

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Shchukina E. S.

2017-03-01

Full Text Available The low level of complexity in the processing of raw materials at mining and processing enterprises adversely affect the environment causing considerable damage to it. Meanwhile technological waste is a cheap source of raw materials for liquid products of functional purpose, particularly inorganic filler which are widely used in the manufacture of paints and building materials, paper, plastics, insulating and protective materials. Improved performance and physical and chemical properties of materials are achieved by optimizing the composition and dispersion of the particles. By the example of the research subjects received from the flotation waste nepheline ore-dressing, it has been shown that a high degree of homogenization to obtain fine mixtures (75 % of 3–4 micron fraction composite filler powders the ultrafine grinding method achieved by using a planetary ball mill for a short period of time (at least 1 hours. The use of other grinding methods, for example by means of ball mill or a vibration such effect is not obtained. At the conditions of ultrafine grinding the ionization and amorphization of the surface layer of powder material particles (mechanical activated processing are occurred. This increases its activity by reacting with organic and inorganic binding, and provides high performance. The obtained filler has been tested in the composition of temperature-controlled sealants and glues used in the aerospace industry, shipbuilding and electronics. To obtain such materials sphene and nepheline received from industrial tailings of Khibiny apatite-nepheline ore deposits are used

Remediation of uranium mill tailings wastes in Australia: a critical review

International Nuclear Information System (INIS)

Mudd, G.M.

2000-01-01

Australia has been an active participant in the global uranium mining industry since its inception in the 1940s. By the late 1950s five major mining and milling projects were operating, several small mines supplied custom ores. All of these projects were closed by the early 1960s, except for Rum Jungle which continued under government subsidy. Most sites have had lasting Environmental impacts. The advances in nuclear power in the 1960s saw increasing demand for uranium and Australia again explored with remarkable success in the Northern Territory, South Australia and Western Australia. After several government inquiries in the 1970s, Ranger, Nabarlek and Olympic Dam were operating by the mid 1980s. The principal risks from uranium mill tailings wastes arise from their radioactive nature and often their chemical toxicities. A critical review of the rehabilitation of abandoned uranium mines and mill tailings as a comparison for current projects is presented. It is concluded that the management of uranium mill tailings wastes is a complex task, requiring a sound multi-disciplinary approach. The problems include groundwater contamination, erosion, radon emanation and gamma radiation. evidence to data from the remediation of old and modern sites does not demonstrate effective long-term closure and safety

Guidelines for the medical surveillance of atomic radiation workers at uranium mines, mills and refineries

International Nuclear Information System (INIS)

1981-01-01

Personnel employed in the mining, milling and refining of uranium ores must, according to Atomic Energy Control Board regulations, be medically examined before beginning employment, at appropriate intervals during their employment, and upon termination. These guidelines are provided for the use of occupational physicians and give advice on procedures to be performed at each type of examination and on the maintenance of medical records. (L.L.)

Extraction of lithium Carbonate from Petalite Ore (Momeik District, Myanmar)

International Nuclear Information System (INIS)

Tun Tun Moe

2011-12-01

The methods for preparing high purity lithium carbonate which can be used for pharmaceutical applications, electronic grade crystals of lithium or to prepare battery-grade lithium metal are disclosed. Lithium carbonate as commercially produced from mineral extraction, lithium containing brines or sea water. One method for the production of pure lithium carbonate from mineral source (petalite ore) obtained from Momeik District, Myanmar is disclosed. Method for mineral processing of ore concentrate is also disclosed.

UMTRA -- The US Uranium Mill Tailings Remedial Action Project

International Nuclear Information System (INIS)

Lightner, R.; Cormier, C.; Bierley, D.

1995-01-01

In the late 1970s, the United States (US) established the first comprehensive regulatory structure for the management, disposal, and long-term care of wastes produced from its domestic uranium processing industry. This regulatory framework was established through the passage of the Uranium Mill Tailings Radiation Control Act of 1978, often referred to as UMTRCA. This legislation created the Uranium Mill Tailings Remedial Action (UMTRA) Project and assigned the US Department of Energy (DOE) the lead in conducting the required remedial action at 24 designated inactive uranium ore processing sites. With the majority of these 22 sites complete, the DOE's UMTRA Project has established a distinguished reputation for safely and effectively remediating these low-level waste sites in a complex regulatory and socioeconomic environment. This paper describes the past accomplishments and current status of the UMTRA Project and discusses the DOE's plans for addressing ground water contamination associated with these sites and its commitment to continuing the long-term care and management of these disposal cells

Innovations over old plant techniques in Jaduguda Uranium Mill expansion

Energy Technology Data Exchange (ETDEWEB)

Siddique, S; Verma, R P; Beri, K K [Uranium Corporation of India Limited, Jaduguda Mines, Singhbhum (India)

1994-06-01

India`s first Uranium Mines and Mills was commissioned at Jaduguda in 1968. The plant`s flowsheet was developed at BARC after extensive tests, for extraction of uranium as yellow cake from the ore. The designed capacity of the process plant was initially 1000 MT/day of ore treatment supplied from nearby mines. Subsequently, due to growing demand of uranium fuel, opening of Bhatin mines and setting up of three plants for recovery of uranium mineral from copper tailings of Hindustan Copper Ltd. was perceived. The capacity of the Jaduguda Plant was increased to 1400 MT/day in 1987 to meet this requirement. A new mine at Narwapahar is under development which will necessitate augmentation of the capacity of the Jaduguda plant by 700 MT/day. Major changes are contemplated in equipment selection for the expansion besides incorporation of a high degree of automation based on microprocessor technology which are discussed in this paper. (author). 4 refs., 5 figs.

Simulation of a high-pressure water jet structure as an innovative tool for pulverizing copper ore in KGHM Polska Miedź S.A.

Directory of Open Access Journals (Sweden)

Przemysław Józef Borkowski

2016-01-01

Full Text Available Effective comminution of copper ore for further processing during flotation is still a challenge, both as a technological problem as well as for the high energy costs of such processing.A high-pressure water jet is one alternative method of preparing copper ore for final flotation, causing distinct enlargement of the surface of micronized particles, which could be profitable for copper production.As a consequence of such innovative processing, particles of copper ore become micronized, ensuring grain fractions directly useful for flotation at the exit of the pulverizing apparatus (the hydro-jetting mill.The paper presents some results of simulation as well as describing an analysis of the phenomena occurring inside the high-pressure water and abrasive-water jets of specific structures, elaborated in the aspect of developing hybrid jets of maximum erosive efficiency, potentially useful for effective pulverization.

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.

Review of the environmental impact of mining and milling of uranium ores

International Nuclear Information System (INIS)

Costello, J.M.; Davy, D.R.; Cattell, F.C.R.; Cook, J.E.

1980-01-01

This review examines some of the environmental impacts of uranium mining and milling including use of natural resources, resulting effluents and the health of uranium workers and the general public. Impacts are expressed in terms of a gigawatt year of electricity (GWe y) generated in a light water reactor (LWR) using the uranium in a once-through fuel cycle. Conclusions of this study are: the actual environmental effects from uranium mining and milling will be site specific; the number of premature deaths from occupational causes is estimated to be between 0.3 and 0.7 per GWe y of energy produced in an LWR with a once through fuel cycle, and of this number between 0.03 and 0.12 per GWe y may arise from cancer associated with radiation exposure and between 0.25 and 0.48 from accidents, and the remainder may result from exposure to siliceous dusts; the number of premature deaths among the general public per GWe y is estimated to be between 0.02 and 0.12 from cancer associated with radiation exposure; and by way of comparison, exposure to a natural background radiation level of 1 mSv y -1 (100 mrem y -1 ) for one year may ultimately lead to an inferred 7 to 30 premature deaths from cancer per million of population, using the same limits of proportionality. In the US, at present rates of consumption, 1 million people use about 1.2 GWe y annually

Impacts of new environmental and safety regulations on uranium mining, milling and waste management in China

International Nuclear Information System (INIS)

Wang Yongping; Zheng Yuhui; Shi Xiangjun

2001-01-01

Nuclear power progress has triggered the development and innovation of nuclear fuel industries in China. At present the Chinese government has put more emphasis on industrial readjustment and technical innovation in uranium mining and milling in order to fuel the nuclear power development, satisfy environmental protection and improve economic efficiency of the industry. The current organizations and approval procedure for establishing regulations and the implementation and consequences of the regulations, technical polices and development strategies concerning uranium mining, milling, treatment of waste ores and mill tailings, and reduction of the workers' suffered exposure dose etc. in China are discussed and the economic, health and environmental impacts of the uranium mining and metallurgy with reformation achievement and the introduction of advanced technologies such as the in-situ leaching and heap leaching mining technologies are assessed in this paper. (author)

Can micro-PIXE measurements help to determine ore genesis ?

International Nuclear Information System (INIS)

Ahmed, M.; Al-Ohali, M.A.

2002-01-01

This study is an attempt to demonstrate how the nuclear micro-PIXE technique can be utilized to investigate ore genesis of geological deposits. Elemental concentrations and distribution profiles in single mineral grains and matrices in a present-day ore deposit on land were measured using the scanning proton microprobe on the 3 MV Tandetron accelerator at King Fahd University of Petroleum and Minerals. Comparing the distribution profiles of some of the trace elements detected it was possible to suggest an organic, sea origin of these deposits. (Author)

Arsenic readily released to pore waters from buried mill tailings

Energy Technology Data Exchange (ETDEWEB)

Mahoney, John [Hydrologic Consultants, Inc., 143 Union Blvd., Suite 525, Lakewood, CO 80228 (United States)]. E-mail: jmahoney@hcico.com; Langmuir, Donald [Hydrochem Systems Corp., P.O. Box 17090, Golden, CO 80402 (United States); Gosselin, Neil [Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Way, Regina, SK, S4S 0A2 (Canada); Rowson, John [COGEMA Resources, Inc., P.O. Box 9204, Saskatoon, SK, S7K 3X5 (Canada)

2005-05-15

At the McClean Lake Operation in the Athabasca Basin of northern Saskatchewan, the untreated acid raffinate solutions associated with U mill tailings contain up to 700 mg/L dissolved As. To reduce the concentration of As and other contaminants in acid tailing slurries at the JEB mill at McClean Lake, ferric sulfate may be added to the acid raffinates to assure that their molar Fe/As ratio equals or exceeds 3. Tailings slurries are then neutralized with lime to pH 4, and subsequently to pH 7-8. The neutralized tailings contain minerals from the original ore, which are chiefly quartz, illite, kaolinite and chlorite, and precipitated (secondary) minerals that include gypsum, scorodite, annabergite, hydrobasaluminite and ferrihydrite. Most of the As is associated with the secondary arsenate minerals, scorodite and annabergite. However, a few percent is adsorbed and/or co-precipitated, mainly by ferrihydrite. Of major concern to provincial and federal regulators is the risk that significant amounts of As might be released from the tailings to pore waters after their subaqueous disposal in the tailings management facility. A laboratory study was performed to address this issue, measuring readily desorbed As using a method known as equilibrium partitioning in closed systems (EPICS). The EPICS method was selected because it employs a leaching solution that, except for its As concentration, is identical in composition to the neutralized raffinate in contact with the tailings. Laboratory experiments and modeling results demonstrated that the As that could be readily released to pore waters is about 0.2% of the total As in the tailings. Long-term, such releases may contribute no more than a few mg/L of dissolved As to tailings pore waters.

Arsenic readily released to pore waters from buried mill tailings

International Nuclear Information System (INIS)

Mahoney, John; Langmuir, Donald; Gosselin, Neil; Rowson, John

2005-01-01

At the McClean Lake Operation in the Athabasca Basin of northern Saskatchewan, the untreated acid raffinate solutions associated with U mill tailings contain up to 700 mg/L dissolved As. To reduce the concentration of As and other contaminants in acid tailing slurries at the JEB mill at McClean Lake, ferric sulfate may be added to the acid raffinates to assure that their molar Fe/As ratio equals or exceeds 3. Tailings slurries are then neutralized with lime to pH 4, and subsequently to pH 7-8. The neutralized tailings contain minerals from the original ore, which are chiefly quartz, illite, kaolinite and chlorite, and precipitated (secondary) minerals that include gypsum, scorodite, annabergite, hydrobasaluminite and ferrihydrite. Most of the As is associated with the secondary arsenate minerals, scorodite and annabergite. However, a few percent is adsorbed and/or co-precipitated, mainly by ferrihydrite. Of major concern to provincial and federal regulators is the risk that significant amounts of As might be released from the tailings to pore waters after their subaqueous disposal in the tailings management facility. A laboratory study was performed to address this issue, measuring readily desorbed As using a method known as equilibrium partitioning in closed systems (EPICS). The EPICS method was selected because it employs a leaching solution that, except for its As concentration, is identical in composition to the neutralized raffinate in contact with the tailings. Laboratory experiments and modeling results demonstrated that the As that could be readily released to pore waters is about 0.2% of the total As in the tailings. Long-term, such releases may contribute no more than a few mg/L of dissolved As to tailings pore waters

Determination of elemental impurities and U and O isotopic compositions with a view to identify the geographical and industrial origins of uranium ore concentrates

Science.gov (United States)

Salaun, A.; Hubert, A.; Pointurier, F.; Aupiais, J.; Pili, E.; Richon, P.; Fauré, A.; Diallo, S.

2012-12-01

First events of illicit trafficking of nuclear and radiological materials occurred 50 years ago. Nuclear forensics expertise are aiming at determining the use of seized material, its industrial history and provenance (geographical area, place of production or processing), at assisting in the identification and dismantling of illicit trafficking networks. This information is also valuable in the context of inspections of declared facilities to verify the consistency of operator's declaration. Several characteristics can be used to determine the origin of uranium ore concentrates such as trace elemental impurity patterns (Keegan et al., 2008 ; Varga et al., 2010a, 2010b) or uranium, oxygen and lead isotopic compositions (Tamborini et al., 2002a, 2002b ; Wallenius et al., 2006; Varga et al., 2009). We developed analytical procedures for measuring the isotopic compositions of uranium (234U/238U and 235U/238U) and oxygen (18O/16O) and levels of elemental impurities (e.g. REE, Th) from very small amounts of uranium ore concentrates (or yellow cakes). Micrometer particles and few milligrams of material are used for oxygen isotope measurements and REE determination, respectively. Reference materials were analyzed by mass spectrometry (TIMS, SF-ICP-MS and SIMS) to validate testing protocols. Finally, materials of unknown origin were analyzed to highlight significant differences and determine whether these differences allow identifying the origin of these ore concentrates. References: Keegan, E., et al. (2008). Applied Geochemistry 23, 765-777. Tamborini, G., et al. (2002a). Analytical Chemistry 74, 6098-6101. Tamborini, G., et al. (2002b). Microchimica Acta 139, 185-188. Varga, Z., et al. (2009). Analytical Chemistry 81, 8327-8334. Varga, Z., et al. (2010a). Talanta 80, 1744-1749. Varga, Z., et al. (2010b). Radiochimica Acta 98, 771-778 Wallenius, M., et al. (2006). Forensic Science International 156, 55-62.

A Review on New Technological Progress for Beneficiation of Refractory Phosphate Ore in China

Science.gov (United States)

Dong, Xu; Siqing, Liu; Yanqing, Yao; Hailin, Liu; Yi, Pei

2017-05-01

The world is rich in phosphate resources, but the vast majority of the resources are of middle and low grade ores, and it is difficult to obtain high grade concentrate at a high recovery by using traditional separation methods. In this paper, the distribution and flotation processes of typical phosphate ores in China are introduced. Considering the current situation in phosphate ore beneficiation both home and abroad, the new trend of processing technology and reagents in China are summarized. Flotation is still regarded as the main processing method in phosphate ore beneficiation for a certain time in near future.

Acid leaching of oxide-sulphide copper ore prior the flotation: A way for an increased metal recovery

Directory of Open Access Journals (Sweden)

Sokić Miroslav D.

2015-01-01

Full Text Available Copper mine "Cerovo"- East Serbia as well as the other ore bodies in its vicinity contain a significant amount of oxide copper minerals in their uper layers (>40%. Processing of such mixed ores by the existing concentration technologies leads to a substantial copper losses (<60%. Reduction of "oxide copper", by acid leaching prior the flotation concentration, can increase the overall copper efficiency up to more than 70% in the single-stage leaching, achieving an efficiency in the flotation concentration stage higher than 75%. Based on the performed experimental results the flow sheet for processing of the mixed oxide-sulphide copper ore is proposed.

Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

Science.gov (United States)

Li, Wen-juan; Liu, Shuang; Song, Yong-sheng; Wen, Jian-kang; Zhou, Gui-ying; Chen, Yong

2016-12-01

The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation-gold concentrate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concentrate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

Ore sorting using natural gamma radiation

International Nuclear Information System (INIS)

Clark, G.J.; Dickson, B.L.; Gray, F.E.

1980-01-01

A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

Converting the Caetité Mill Process to Enhance Uranium Recovery and Expand Production

Energy Technology Data Exchange (ETDEWEB)

Gomiero, L. A.; Scassiotti Filho, W.; Veras, A., E-mail: gomiero@inb.gov.br [Indústrias Nucleares do Brasil S/A — INB, Caetité, BA (Brazil); Cunha, J. W. [Instituto de Engenharia Nuclear-IEN/CNEN, Rio de Janeiro, RJ (Brazil); Morais, C. A. [Centro do Desenvolvimento da Tec. Nuclear-CDTN/CNEN, Belo Horizonte, MG (Brazil)

2014-05-15

The Caetité uranium mill was commissioned in 2000 to produce about 340 t U per year from an uranium ore averaging 0.29% U{sub 3}O{sub 8}. This production is sufficient to supply the two operating nuclear power plants in the country. As the Brazilian government has recently confirmed its plan to start building another ones from 2009, the uranium production will have to expand its capacity in the next two years. This paper describes the changes in the milling process that are being evaluated in order to not only increase the production but also the uranium recovery, to fulfil the increasing local demand. The heap leaching process will be changed to conventional tank agitated leaching of ground ore slurry in sulphuric acid medium. Batch and pilot plant essays have shown that the uranium recovery can increase from the 77% historical average to about 93%. As the use of sodium chloride as the stripping agent has presented detrimental effects in the extraction and stripping process, two alternatives are being evaluated for the uranium recovery from the PLS: (a) uranium peroxide precipitation at controlled pH from a PLS that was firstly neutralized and filtered. Batch essays have shown good results with a final calcined precipitate averaging 99% U{sub 3}O{sub 8}. Conversely the results obtained at the first pilot plant essay has shown that the precipitation conditions of the continuous process calls for further evaluation. The pilot plant is being improved and another essay will be carried out. (b) uranium extraction with a tertiary amine followed by stripping with concentrated sulphuric acid solution. Efforts are being made to recover the excess sulphuric acid from the pregnant stripping solution to enhance the economic viability of the process and to avoid the formation of a large quantity of gypsum in the pre-neutralization step before the uranium peroxide precipitation. (author)

Carbothermic reduction behaviors of Ti-Nb-bearing Fe concentrate from Bayan Obo ore in China

Science.gov (United States)

Wang, Guang; Du, Ya-xing; Wang, Jing-song; Xue, Qing-guo

2018-01-01

To support the development of technology to utilize low-grade Ti-Nb-bearing Fe concentrate, the reduction of the concentrate by coal was systematically investigated in the present paper. A liquid phase formed when the Ti-Nb-bearing Fe concentrate/coal composite pellet was reduced at temperatures greater than 1100°C. The addition of CaCO3 improved the reduction rate when the slag basicity was less than 1.0 and inhibited the formation of the liquid phase. Mechanical milling obviously increased the metallization degree compared with that of the standard pellet when reduced under the same conditions. Evolution of the mineral phase composition and microstructure of the reduced Ti-Nb-bearing Fe concentrate/coal composite pellet at 1100°C were analyzed by X-ray diffraction and scanning electron microscopy-energy-dispersive spectroscopy. The volume shrinkage value of the reduced Ti-Nb-bearing Fe concentrate/coal composite pellet with a basicity of 1.0 was approximately 35.2% when the pellet was reduced at 1100°C for 20 min, which enhanced the external heat transfer to the lower layers when reduced in a practical rotary hearth furnace. The present work provides key parameters and mechanism understanding for the development of carbothermic reduction technology of a Ti-Nb-bearing Fe concentrate incorporated in a pyrometallurgical utilization flow sheet.

Rare earth elements materials production from apatite ores

International Nuclear Information System (INIS)

Anufrieva, A V; Buynovskiy, A S; Makaseev, Y N; Mazov, I N; Nefedov, R A; Sachkov, V I; Valkov, A V; Andrienko, O S; Stepanova, O B

2016-01-01

The paper deals with the study of processing apatite ores with nitric acid and extraction of the rare earth elements. The rare earth elements can be successfully separated and recovered by extraction from the nitrate- phosphate solution, being an tributyl phosphate as extraction agent. The developed scheme of the processing apatite concentrate provides obtaining rare earth concentrates with high qualitative characteristics. (paper)

Uranium and thorium mining and milling: material security and risk assessment

International Nuclear Information System (INIS)

Steinhaeusler, F.; Zaitseva, L.

2005-01-01

Full text: At present physical protection for the front end of the nuclear fuel cycle is typically at a significantly lower level than at any other part of the nuclear fuel cycle. In view of past experiences (Israel, South Africa, Pakistan, India) it is feasible to take into consideration some generic threat scenarios, potentially resulting in loss of control over uranium or thorium, respectively their concentrates, such as: illegal mining of an officially closed uranium- or thorium mine; covert diversion of uranium- or thorium ore whilst officially mining another ore; covert transport of radioactive ore or product, using means of public rail, road, ship, or air transport; covert en route diversion of an authorized uranium- or thorium transport; covert removal of uranium-or thorium ore or concentrate from an abandoned facility. The Stanford-Salzburg database on nuclear smuggling, theft, and orphan radiation sources (DSTO) contains information on trafficking incidents involving mostly uranium, but also some thorium, from 30 countries in five continents with altogether 113 incidents in the period 1991 to 2004. These activities range from uranium transported in backpacks by couriers in Afghanistan, to a terrorist organization purchasing land in order to mine covertly for uranium in Australia, and the clandestine shipment of almost two tons of uranium hexafluoride from Asia to Africa, using the services of a national airline. Potential participants in such illegal operations range from entrepreneurs to members of organized crime, depending on the level of sophistication of the operation. End-users and 'customers' of such illegal operations are suspected to be non-state actors, organizations or governments involved in a covert operation with the ultimate aim to acquire a sufficient amount of nuclear material for a nuclear device. The actual risk for these activities to succeed in the acquisition of an adequate amount of suitable radioactive material depends on one or

Uranium recovery from phosphate rocks concentrated

International Nuclear Information System (INIS)

Azevedo, M.F. de.

1986-01-01

The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

X-ray radiometric method of ore quality monitoring during mining

International Nuclear Information System (INIS)

Ivanyukovich, G.A.

1979-01-01

The method is basically applied for sampling ore deposits, mainly of nonferrous and rare metals. It can be used for determining one, two or three elements in the deposit. In the USSR, the method has so far been used in Far East tin deposits and in the North Caucasus tungsten-molybdenum deposit. It is used for the analysis of boreholes, shaft walls, mined ore and ore material intended for enriching. The instruments used include single-channel gamma spectrometers using scintillation or proportional counters as detectors. Logging instruments include dual-channel spectrometers featuring automatic gain control and data processing devices. The instruments are designed for separating elements with atomic numbers 19 to 88 from mine wall materials and with atomic numbers 26 to 88 in boreholes at concentrations exceeding 0.1% and 0.01% for tin and silver, respectively. The economic benefit is shown of the introduction of the method using the Sadon lead-zinc plant and Khrustalnensk ore treatment plant as examples. (H.S.)

Uranium mining and milling environmental studies. February 1984-May 1987 (A Bibliography from the NTIS data base). Report for February 1984-May 1987

International Nuclear Information System (INIS)

1990-05-01

This bibliography contains citations concerning environmental and social aspects of uranium mining, milling, and ore treatment. Environmental and social aspects include air and water pollution, public health, occupational safety, land reclamation, and waste disposal. The citations refer to monitoring and control of contaminants, and environmental surveys and impact statements for specific areas in the vicinity of mining and ore treatment facilities. There are also references to health studies performed on miners and millworkers. (This updated bibliography contains 349 citations, none of which are new entries to the previous edition.)

Studies on uranium ore processing

International Nuclear Information System (INIS)

Kim, C.H.; Park, S.W.; Lim, J.K.; Chung, M.K.

1981-01-01

Chemical and chemical engineering techniques of the uranium ore processing established by France COGEMA (Compagnie Generale des Matieres Nucleaires) have been comprehensively reviewed in preparation for successful test operation of the pilot plant to be completed by the end of 1981. It was found that the amount of sulfuric acid (75 Kg/t, ore) and sodium chlorate (2.5 Kg/t, ore) recommended by COGEMA should be increased up to 100 Kg/t, ore and 10 Kg/t, ore respectively to obtain satisfactory leach of uranium for some ore samples produced at the different pits of Goesan uranium mine. Conditions of the other processes such as solvent extraction, stripping, and precipitation of yellow cake were generally agreed with the results of intensive studies done by this laboratory

Modelling Of Monazite Ore Break-Down By Alkali Process Spectrometry

International Nuclear Information System (INIS)

Visetpotjanakit, Suputtra; Changkrueng, Kalaya; Pichestapong, Pipat

2005-10-01

A computer modelling has been developed for the calculation of mass balance of monazite ore break-down by alkali process at Rare Earth Research and Development Center. The process includes the following units : ore digestion by concentrate NaOH, dissolution of digested ore by HCl, uranium and thorium precipitation and crystallization of Na3PO4 which is by-product from this process. The model named RRDCMBP was prepared in Visual Basic language. The modelling program can be run on personal computer and it is interactive and easy to use. User is able to choose any equipment in each unit process and input data to get output of mass balance results. The model could be helpful in the process analysis for the further process adjustment and development

New interpretation of the dominant ore-controlling factor of the uranium ore field No. 322

International Nuclear Information System (INIS)

Liu Xiang; Yang Chongqiu

1996-01-01

The NE-trending fault structures in ore field NO. 322 are characterized by compress-shearing, left-Lateral left-slipping, having an obvious control over the Localisation of the ore field No. 322, and are the dominant ore-controlling factor of the ore field NO.322. Resulting from the sinistral displacement of the NE-trending fault, there is a pull-apart basin in the Feng Zhou area. The formation and evolution of the NE-trending fault zone and the Feng Zhou basin control the formation of uranium deposits of ore field No. 322

Composition, distribution, and hydrologic effects of contaminated sediments resulting from the discharge of gold milling wastes to Whitewood Creek at Lead and Deadwood, South Dakota

Science.gov (United States)

Goddard, K.E.

1989-01-01

The Whitewood Creek-Belle Fourche-Cheyenne River stream system in western South Dakota has been extensively contaminated by the discharge to Whitewood Creek of about 100 million tons of mill tailings from gold-mining operations. The resulting contaminated sediments contain unusually large concentrations of arsenic, as much as 11,000 micrograms/g, derived from the mineral arsenopyrite, as well as potentially toxic constituents derived from the ore-body minerals or from the milling processes. Because of the anomalous arsenic concentrations associated with the contamination, arsenic was used as an indicator for a geochemically based, random, sediment-sampling program. Arsenic concentrations in shallow, contaminated sediments along the flood plains of the streams were from 1 to 3 orders of magnitude larger than arsenic concentrations in uncontaminated sediments in about 75% of the flood plains of Whitewood Creek and the Belle Fourche River. Appreciable surface-water contamination resulting from the contaminated sediments is confined to Whitewood Creek and a reach of the Belle Fourche River downstream from the mouth of Whitewood Creek. In Whitewood Creek , dissolved-arsenic concentrations vary from about 20 to 80 microgram/L during the year in response to variations in groundwater inflow and dilution, whereas total-recoverable-arsenic concentrations vary from about 20 to 8 ,000 micrograms/L during short periods in response to rapid changes in suspended-sediment concentration. Contamination of the alluvial aquifer along the stream system is limited to areas in direct contact with large deposits of contaminated sediments. Within the aquifer, arsenic concentrations are thought to be controlled by sorption-desorption on metallic hydroxides. (USGS)

Predictive geochemical modeling of contaminant concentrations in laboratory columns and in plumes migrating from uranium mill tailings waste impoundments

International Nuclear Information System (INIS)

Peterson, S.R.; Martin, W.J.; Serne, R.J.

1986-04-01

A computer-based conceptual chemical model was applied to predict contaminant concentrations in plumes migrating from a uranium mill tailings waste impoundment. The solids chosen for inclusion in the conceptual model were selected based on reviews of the literature, on ion speciation/solubility calculations performed on the column effluent solutions and on mineralogical characterization of the contacted and uncontacted sediments. The mechanism of adsorption included in the conceptual chemical model was chosen based on results from semiselective extraction experiments and from mineralogical characterization procedures performed on the sediments. This conceptual chemical model was further developed and partially validated in laboratory experiments where assorted acidic uranium mill tailings solutions percolated through various sediments. This document contains the results of a partial field and laboratory validation (i.e., test of coherence) of this chemical model. Macro constituents (e.g., Ca, SO 4 , Al, Fe, and Mn) of the tailings solution were predicted closely by considering their concentrations to be controlled by the precipitation/dissolution of solid phases. Trace elements, however, were generally predicted to be undersaturated with respect to plausible solid phase controls. The concentration of several of the trace elements were closely predicted by considering their concentrations to be controlled by adsorption onto the amorphous iron oxyhydroxides that precipitated

The role of post-ore processes in the alteration of infiltrational uranium deposits

International Nuclear Information System (INIS)

Kondrat'eva, I.A.; Bobrova, L.L.; Nesterova, M.V.

1992-01-01

Ore-bearing rocks and ores of uranium deposits that are associated with gray alluvial deposits and formed through oxidation of sedimentary beds at the end of the Jurassic, have undergone intensive alterations. The impact of hot carbonic acid solutions on infiltrational uranium deposits, along with calcite and hematite, resulted in partial dissolution of and redeposition of uranium. Uranium concentrates with newly formed Fe-bisulfides and hydroxides in the reducing stage of epigenetic alterations within a hydrochemical sulfide-gley medium, leading to changes in ore morphology. 20 refs., 7 figs., 3 tabs

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.

A study on the upgrading by physical means of low grade uranium ore from Phu Wiang District

International Nuclear Information System (INIS)

Wihokratna, W.

1980-01-01

The purpose of this thesis is to upgrade the uranium ore at Phu Wiang district. Because of the fine grains and high degree of dissemination of uranium in ores, resulting practically complete envelopment of the uranium minerals by the gangue minerals, the ore must first undergo digestion in order to reveal the uranium minerals. After digestion, sodium hydroxide of 0.05 normal was added to the ore and the mixture was fed into the agitator provided with baffles and two specially designed propellers. Due to the 'Push - Pull' motion of the propellers a zone of specially high turbulence was created between them. Also in this region higher concentration of uranium is revealed and the high concentrated uranium ore was regularly stripped off for further analysis. It was found that by using mineral of grain size of 100 mesh and 0.0187% of uranium content a concentration up to 0.063% uranium content (an upgrading better than by a factor of three times) was achieved with the above method. The uranium content was analyzed with 3'' x 3'' NaI (Tl) detector and 1024 channels MCA

The determination of trace quantities of thorium and uranium in thick ore samples by proton-induced x-ray emission

International Nuclear Information System (INIS)

Cohen, D.D.; Duerden, P.; Clayton, E.

1979-07-01

Proton-induced X-ray emission (PIXE) techniques have been used to estimate the concentrations of trace quantities of thorium and uranium in powdered rock and ore samples. Standards of known concentrations were prepared in a carbon matrix and the yields from these used to determine simultaneously the concentrations of thorium and uranium in the ore samples. The experimental detection limit of the technique was found to be 3 to 4 μg g -1 for a 100 μC irradiation. The appropriate matrix corrections for a carbon and ore matrix have been calculated for thick targets and taken into consideration

Spectrometric gamma investigations concerning zinc-lead ores and the products of their processing

International Nuclear Information System (INIS)

Girczys, J.; Skowronek, J.; Zrodlowski, B.

1983-01-01

Zinc-lead ore and products of its enrichment were investigated using gamma spectrometry for the content of uranium, thorium and potassium 40. It was stated that the mean content of these elements in a deposit does not diverge from their mean concentration in the lithosphere. They also accompany the surrounding rocks. As a result of mechanical processing of this ore radionuclides pass discards in which they do not form concentrations dangerous for life, either. In the exploitation areas and in the surroundings there is no state of ecological hazard. (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

Unpredictable changes in demand and prices varying from very attractive to depressing levels have thrown all Manganese ore mines out of normal operating gear. The supply has to be in time-bound fashion, of dependable quality and continuous. With setting-up of numerous small units and with existing ferro-alloy units, ore supply has become extremely sensitive issue. Due to unpredictable swing in price of Mn ore lumps, furnace operators found it economic and convenient to use fines, even at great risks to furnace equipment and operating persons and therefore risks & damages were conveniently & comfortably ignored. Beneficiation Cost(Operating) approx. - (ferruginous ore) - Roast reduction followed by magnetic separation route-particulars - Water 20/-, Power 490/-, Coal fines-675/-, OH-250/-totaling to Rs.1435/T. (Figures are based on actual data from investigations on Orissa & Karnataka sector ores). Feed Grade Mn- 28 to 32 %, Fe - 14 to 25 %, Concentrate (Beneficiated ore fines)- - Mn- 45 to 48 %, Fe - 6 to 8 %., Recovery - 35 %, Price of 28-30 % Mn ore fines = Rs. 2400/T, Cost of Concentrated fines (45/48% Mn grade) = Rs. 8300/T, Price of 47-48 % Mn Lumpy ore = Rs.11,000/T. Sintering Cost (Operating) - Approx-Rs.1195=00/T Sinter. Therefore cost of Sinter produced from beneficiated concentrate is 9130+1195 = Rs. 10325. The difference in cost of 48%Mn ore Lumps & 48%Mn sintered concentrate = 11000-10325 = Rs.675/T. The main purpose of this paper is to show that establishment of beneficiation unit & Sintering unit is economically feasible. There are many misconcepts, still prevailing, about use of Mn ore sinters. Few of the main misconcepts are- 1)Sinters bring no benefit - technical or economical.2) Sinters are very friable and disintegrate easily into high fines during handling/transportation. 3) Fines below 100 mesh cannot be sintered. 4) Silica increases to high level during sintering, resulting in to high slag volume thereby higher power consumption. All are false

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

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)

Ore sorting

International Nuclear Information System (INIS)

Hawkins, A.P.; Richards, A.W.

1982-01-01

In an ore sorting apparatus, ore particles are bombarded with neutrons in a chamber and sorted by detecting radiation emitted by isotopes of elements, such as gold, forming or contained in the particles, using detectors and selectively controlling fluid jets. The isotopes can be selectively recognised by their radiation characteristics. In an alternative embodiment, shorter life isotopes are formed by neutron bombardment and detection of radiation takes place immediately adjacent the region of bombardment

Research of geological technologic condition in laboratory about the ore of 501 deposits

International Nuclear Information System (INIS)

Ma Guoxiang; Yu Baoli; Gao Yuyou; Li Changhua

2009-01-01

501 deposits of uranium ore grade is 0.052%. The radio of U +6 /U 4+ is 1.7-4.6. there is less content of sarbonate, such as sulfide and organic matter which disservice baptist uranium geological process, and the uranium and oxygen with a high level in the water of seam. The content of [HCO 3 ] - is lower. By conducting the static leaching test, the important technical parameters of uranium ore extraction are determined: with 7.91 g/L H 2 SO 4 , to soak uranium ore which the grade is between 0.007% and 0.216% for 48 hours, the uranium extraction rate of 64.69-99.17%, and extract uranium concentration 9.51-427.6 mg/L; the formula of infusion solution is obtained by using percolation leaching test: 6-8 g/L H 2 SO 4 , the rate of uranium extraction is 95.71%-96.33%, an average of leaching solution uranium concentration of 88.33-111.32 mg/L, leaching liquid-solid ratio of 4.46-5.66, ore tons of sulfuric acid consumption to 27.58-29.83 kg/t, extraction of uranium 1 kg of sulfuric acid consumption to 55.17-60.06 kg. That indicate the geological technologic conditions which the leaching of uranium ore deposits is better. (authors)

Radon and Thoron emanation testwork on Nolans Rare Earths ores

International Nuclear Information System (INIS)

Sonter, Mark; Grose, Jeremy

2016-01-01

This paper reports on a series of experiments performed on two bulk ore samples for Arafura Resources' Nolans Rare Earths project, intended to derive information on radon (Rn222) and thoron (Rn220) emanation rates (fluxes) under various circumstances. This data is needed to enable development of predictions of Rn and Tn releases from exposed mine bench ore, ore stockpiles, and tailings, and thus assist in estimation of airborne concentrations within the areas of the future Mine and Processing plant. In turn these estimates will provide guidance on the quantitative risk and the necessity or otherwise of invoking specific control measures, either in design or in operating procedures. This testwork was carried out during the period 2nd to 15th July, at Arafura's Winnellie facility in Darwin. Conclusions are that for uncrushed ore, Rn flux numbers are around 1.0Bq/m"2/s, Tn numbers appear to cluster around 200-300 Bq/m"2/s. Crushing gave no change in Rn flux, Tn flux was doubled for calc-silicate material. Wetting gave significant reductions for both Rn and Tn for ores sampled, and clay capping reduced Rn flux marginally but Tn was reduced by a factor of 100.

Purification of trona ores by conditioning with an oil-in-water emulsion

Science.gov (United States)

Miller, J. D.; Wang, Xuming; Li, Minhua

2009-04-14

The present invention is a trona concentrate and a process for floating gangue material from trona ore that comprises forming an emulsion, conditioning the trona ore at a high solids content in a saturated trona suspension, and then floating and removing the gangue material. The process for separating trona from gangue materials in trona ore can include emulsifying an oil in an aqueous solution to form an oil-in-water emulsion. A saturated trona suspension having a high solids content can also be formed having trona of a desired particle size. The undissolved trona in the saturated suspension can be conditioned by mixing the saturated suspension and the oil-in-water emulsion to form a conditioning solid suspension of trona and gangue material. A gas can be injected through the conditioning solid suspension to float the gangue material. Thus, the floated gangue material can be readily separated from the trona to form a purified trona concentrate without requirements of additional heat or other expensive processing steps.

Optimisation Platform for copper ore processing at the Division of Concentrator of KGHM Polska Miedz S.A.

Directory of Open Access Journals (Sweden)

Kuzba Bogdan

2016-01-01

Full Text Available The idea of Optimisation Platform is to create an innovative system. It is dedicated to technology and cost efficiency improvement of process realized at the Division of Concentrators of KGHM Polska Miedz SA. This highly sophisticated tool is based on visual, acoustic and vibrating detection systems. The range of its functionality was described in this work. Three main utility modules were described: froth flotation image processing (FloVis, grinding and classification monitoring (MillVis and belt conveyors control unit (ConVis. The effects of implementation of the system under KGHM conditions were described. It is concluded that the Optimisation Platform is one of the most promising solution for improvement of technology and economy performance at the Division of Concentrators of KGHM Polska Miedz S.A.

Practical aspects of monitoring and dosimetry of long-lived dust in uranium mines and mills - determination of the annual limit on intake for uranium and uranium/thorium ore dust

International Nuclear Information System (INIS)

Duport, P.; Horvath, F.

1989-01-01

Based on the recommendations of ICRP Publication 26, the dosimetric and metabolic data of ICRP Publication 30, and using available information on the physical and solubility characteristics of uranium and uranium/thorium ore, the ALI values for airborne ore dust were calculated. Four hypothetical types of ore were considered: uranium ore with no radon emanation, uranium ore with 50% radon emanation, uranium/thorium ore with neither 222 Rn nor thoron emanation, and uranium/thorium ore with 50% 22 Rn and 220 Rn emanation. Furthermore, the ALI values were calculated assuming the radionuclides present in the ore were all: (a) solubility class Y: (b) solubility class W; and (c) equal parts of classes Y and W. The ALI values were also calculated for Activity Median Aerodynamic Diameters (AMAD) ranging from 1 to 10 μm. The results of the calculations show that the solubility class of the radionuclides is the single most important factor that governs ALI values. The ALI value for uranium and uranium-thorium ore dust is proportional to (AMAD) 0.5 for class Y materials, (AMAD) 0.2 for a mixture of equal parts of class Y and class W materials, and is independent of the AMAD for class W materials. A series of graphs is given from which it is possible to evaluate the ALI for airborne ore dust when the AMAD of the dust and the solubility characteristics are known approximately. (author)

Cameco engineered tailings program: linking applied research with industrial processes for improved tailings performance

International Nuclear Information System (INIS)

Kotzer, T.G.

2010-01-01

'Full text:' Mine tailings at Cameco's operations are by-products of milling uranium ore having variable concentrations of uranium, metals, oxyanions and trace elements or elements of concern (EOC). Cameco has undertaken an Engineered Tailings (ET) program to optimize tailings performance and minimize environmental EOC impacts, regardless of the milled ore source. Applied geochemical and geotechnical tailings research is key within the ET program. In-situ drilling and experimental programs are used to understand long-term tailings behaviour and help validate source term predictions. Within this, the ET program proactively aids in the development of mill-based processes for production of tailings having improved long-term stability. (author)

Treatment of waste water from uranium ore preparation

International Nuclear Information System (INIS)

Klicka, V.; Mitas, J.; Vacek, J.

1976-01-01

An improved closed-loop process is described for treating waste water resulting from chemical extraction of uranium from ore. The water is evaporated to form a concentrated solution and is then subjected to crystallization of the least soluble salt component thereof via further evaporation, or cooling or simultaneous cooling and a partial vacuum. The crystallized component is then separated from the mother liquor, whereupon the latter is fed back after removal of residual uranium therefrom to the extraction installation to replace the acids used therein. Additionally, the pure condensate produced during evaporation of the waste waters is employed as a replacement for the fresh water employed in processing of the ore. 6 claims, 2 figures

Characterization of long-lived radioactive dust clouds generated in uranium mill operations

International Nuclear Information System (INIS)

Bigu, J.

1987-01-01

The characteristics of long-lived radioactive dust clouds generated in several mechanical and physico-chemical operations in a uranium mill have been investigated. The study consisted of the determination of dust size distribution, and of the radionuclides contained in the particles of each dimension class ranging from <0.1 to 26 μm in diameter. Experiments were conducted using several cascade impactors operating at different sample flow rates. Two different types of cascade impactors were used. Radionuclide identification was done using α-spectrometry and γ-spectrometry. Long-lived and short-lived radionuclides were identified in dust samples. The characteristics of the dust clouds depended on the mill operation. The following operations were studied: crushing (vibrating grizzly, jaw crusher, cone crusher); screening; ore transportation; grinding; acid leaching; counter-current decantation; yellowcake precipitation and drying; and yellowcake packaging. In addition, other dust and radioactivity measurements have been carried out

Code of practice on the management of radioactive wastes from the mining and milling of radioactive ores 1982

International Nuclear Information System (INIS)

Anon.

1982-01-01

This Code, issued by the Department of Home Affairs and Environment, was formulated under the provisions of the Environment Protection (Nuclear Codes) Act 1978. The Code provides for prior development, approval and subsequent updating of a waste management programme for each mining or milling operation to which it applies, for the purpose of ensuring an approach to waste management best suited to the particular circumstances of each operation. It also prescribes the duties of the owners, operators and managers of mines and mills. (NEA) [fr

Processing of low-grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1975-01-01

Four types of low grade ores are studied. Low grade ores which must be extracted because they are enclosed in a normal grade deposit. Heap leaching is the processing method which is largely used. It allows to obtain solutions or preconcentrates which may be delivered at the nearest plant. Normal grade ores contained in a low amplitude deposit which can be processed using leaching as far as the operation does not need any large expensive equipment. Medium grade ores in medium amplitude deposits to which a simplified conventional process can be applied using fast heap leaching. Low grade ores in large deposits. The processing possibilities leading to use in place leaching are explained. The operating conditions of the method are studied (leaching agent, preparation of the ore deposit to obtain a good tightness with regard to the hydrological system and to have a good contact between ore and reagent) [fr

Beneficiation studies on low-grade complex polymetallic lead-zinc ore of duddar (lasbela) Balochistan, Pakistan

International Nuclear Information System (INIS)

Bhatti, M.R.; Kazim, K.R.; Mehmood, R.; Akram, A.

2016-01-01

A bench-scale beneficiation study was performed on low-grade complex lead-zinc ore of Duddar area, District Lasbela, Balochistan Province, Pakistan. The polymetallic ore under investigation contains galena and sphalerite as valuable minerals of lead and zinc. The low-grade ore was upgraded by selective sequential froth flotation technology to recover both minerals. An effort was made to investigate the effect of important variables on grade and recovery of concentrates and to design the process flow sheet. Different parameters of flotation process such as particle size of the feed, pH and % solids of the pulp, speed of impeller, type of reagents (collectors, frothers, regulators and modifiers) and their quantities, conditioning time and flotation time were optimized to attain maximum grade and recovery of respective concentrates. The rougher concentrates obtained were subjected to one regrinding and two cleaning operations to achieve higher-grade concentrates of both metals. Bench-scale flotation tests show that it is possible to obtain a lead concentrate assaying 65.24% Pb with recovery rate of 81.32% and a zinc concentrate containing 55.63% Zn content with recovery rate of 80.28%. Both the concentrates meet the specifications required for metallurgical and chemical grades. (author)

The dispersion of fine chitosan particles by beads-milling

Science.gov (United States)

Rochima, Emma; Utami, Safira; Hamdani, Herman; Azhary, Sundoro Yoga; Praseptiangga, Danar; Joni, I. Made; Panatarani, Camellia

2018-02-01

This research aimed to produce fine chitosan particles from a crab shell waste by beads-milling method by two different concentration of PEG as dispersing agent (150 and 300 wt. %). The characterization was performed to obtain the size and size distribution, the characteristics of functional groups and the degree of deacetylation. The results showed that the chitosan fine particles was obtained with a milling time 120 minutes with the best concentration of PEG 400 150 wt. %. The average particle size of the as-prepared suspension is 584 nm after addition of acetic acid solution (1%, v/v). Beads milling process did not change the glucosamine and N-acetylglucosamine content on chitosan structure which is indicated by degree of deacetylation higher than 70%. It was concluded that beads milling process can be applied to prepare chitosan fineparticles by proper adjustment in the milling time, pH and dosage of dispersing agent.

Beneficiation strategy for some low grade ores of strategic metals in India

International Nuclear Information System (INIS)

Krishna Rao, N.

1997-01-01

In developing indigenous resources of strategic metals, beneficiation strategy has a major role to play, particularly where the ores are of low tenor. Presently India imports most of its requirements of metals like tin, tungsten, molybdenum, nickel and cobalt. In all these cases important low grade resources occur in the country. Beneficiation strategy necessary for exploitation of these deposits are discussed based mainly on vast batch and semi plant scale data generated in the Ore Dressing Section of Bhabha Atomic Research Centre. Also discussed is the case of strategic metal uranium where, in certain cases pre-concentration by beneficiation has the potential to make it feasible the exploitation of otherwise difficult to process ore resources. (author)

Uranium R and D directed to low-grade ores

International Nuclear Information System (INIS)

Anon.

1976-01-01

The treatment of depleted uranium ores by in-situ leaching and by counterflow ion exchange in the USA is described. In-situ leaching is mainly suitable for sandstone deposits. The research was originally focused on leaching with an acid and with carbonates. Phosphoric acid appears to be a promising leaching agent. The equipment for continuous ion exchange may be used for sludge processing but the application depends on the type of equipment and mineralogy of processed ores. The method is advantageous for lower capital costs and for smooth operation. Ion exchange is also used for uranium extraction from mine waters in the USA as well as in Canada. For example, in Grants, New Mexico, a yield exceeding 90% was reached in mine waters only containing 5 to 7 ppm U 3 O 8 . In the future, the treatment of ores with a low uranium content will require more selective extraction methods in view of the more stringent technical conditions of uranium concentrate processing. (J.P.)

226Ra and 210Pb relationship in solid wastes and plants at Uranium mill tailing

International Nuclear Information System (INIS)

Madruga, M.J.; Faria, I.; Brogueira, A.

2002-01-01

After the uranium extraction from the ore, the waste residues (tailings) contain several radionuclides in elevated levels comparing to normal soils. Nearly all of the uranium progenies (2 30T h, 2 26R a, 2 10P b and 2 10P o) and the unextracted uranium fraction are present in tailings. These large quantities of tailings may provide a significant source of environmental and food chain contamination. The transfer of radioisotopes between different ecological compartments is frequently evaluated using ratios which relate the radionuclide content in one ecosystem compartment to that of another. For instance, the concentration ratio (CR), i.e., the ratio between radionuclide concentrations in tailings and plants can be evaluated. Radium-226, a long-lived alfa emitter, is a chemical analog of calcium. The 2 26R a uptake is similar to calcium in biological and ecological systems. The uptake of 2 10P b will follow the same pattern as natural lead. Plants do not require lead but in contrast they require the Ra/Ca group elements. The uptake of lead is mainly a function of the lead tolerance of the plant and the hydrogen ion concentration of the soil. Kalin and Sharma (1982) reported that 2 26R a and 2 10P b uptake by indigenous species from inactive uranium mill tailings in Canada differ from the uptake of the elements by the same plants growing in soil. Ibrahim and Whicker (1992) reported that tailing acidity tends to enhance radionuclide availability for plant uptake. The transport of radionuclides to foliage and subsequent retention and absorption may play a role in plant contamination. The main goal of this study is to evaluate the 2 26R a and 2 10P b relationship in tailings and plants growing at uranium mill tailings

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

Ford, H.L.; Levine, N.M.; Risdon, A.R.

1975-01-01

A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

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.

Blue-shift in photoluminescence of ion-milled HgCdTe films and relaxation of defects induced by the milling

International Nuclear Information System (INIS)

Pociask, M.; Izhnin, I.I.; Mynbaev, K.D.; Izhnin, A.I.; Dvoretsky, S.A.; Mikhailov, N.N.; Sidorov, Yu.G.; Varavin, V.S.

2010-01-01

Simultaneous measurements of electrical conductivity, the Hall coefficient, and photoluminescence (PL) spectra of ion-milled Hg 1 - x Cd x Te films (x ∼ 0.30 and 0.38) were performed during post-milling ageing of the films at 293 K. In the course of the PL study, a 'relaxation' of the blue-shift of the PL band of ion-milled Hg 0.70 Cd 0.30 Te was observed. The relaxation was caused by the decrease of the electron concentration due to gradual disintegration of defects induced by the milling. It is shown that while ion milling substantially changes the electrical properties of Hg 1 - x Cd x Te, its PL spectrum in the long-term is affected insignificantly.

Groundwater leaching of neutralized and untreated acid-leached uranium-mill tailings

International Nuclear Information System (INIS)

Gee, G.W.; Begej, C.W.; Campbell, A.C.; Sauter, N.N.; Opitz, B.E.; Sherwood, D.R.

1981-01-01

Tailings neutralization was examined to determine the effect of neutralization on contaminant release. Column leaching of acid extracted uranium mill tailings from Exxon Highland Mill, Wyoming, Pathfinder Gas Hills Mill, Wyoming, and the Dawn Midnite Mill, Washington, resulted in the flushing of high concentrations of salts in the first four pore volumes of leachate, followed by a steady decrease to the original groundwater salt concentrations. Neutralization decreased the concentration of salts and radionuclides leaching from the tailings and decreased the volume of solution required to return the solution to the groundwater pH and EC. Radium-226 and uranium-238 leached quickly from the tailings in the initial pore volumes of both neutralized and unneutralized tailings, and then decreased significantly. 6 figures, 5 tables

Dependence of rates of breakage on fines content in wet ball mill grinding

Science.gov (United States)

Bhattacharyya, Anirban

The following research fundamentally deals with the cause and implications of nonlinearities in breakage rates of materials in wet grinding systems. The innate dependence of such nonlinearities on fines content and the milling environment during wet grinding operations is also tested and observed. Preferential breakage of coarser size fractions as compared to the finer size fractions in a particle population were observed and discussed. The classification action of the pulp was deemed to be the probable cause for such a peculiarity. Ores with varying degrees of hardness and brittleness were used for wet grinding experiments, primarily to test the variations in specific breakage rates as a function of varying hardness. For this research, limestone, quartzite, and gold ore were used. The degree of hardness is of the order of: limestone, quartzite, gold ore. Selection and breakage function parameters were determined in the course of this research. Functional forms of these expressions were used to compare experimentally derived parameter estimates. Force-fitting of parameters was not done in order to examine the realtime behavior of particle populations in wet grinding systems. Breakage functions were established as being invariant with respect to such operating variables like ball load, mill speed, particle load, and particle size distribution of the mill. It was also determined that specific selection functions were inherently dependent on the particle size distribution in wet grinding systems. Also, they were consistent with inputs of specific energy, according to grind time. Nonlinearity trends were observed for 1st order specific selection functions which illustrated variations in breakage rates with incremental inputs of grind time and specific energy. A mean particle size called the fulcrum was noted below which the nonlinearities in the breakage trends were observed. This magnitude of the fulcrum value varied with percent solids and slurry filling, indicating

Sampling of ore

International Nuclear Information System (INIS)

Boehme, R.C.; Nicholas, B.L.

1987-01-01

This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

Uranium exploration, mining and milling proposal, Navajo Indian Reservation, New Mexico

International Nuclear Information System (INIS)

Babby, W.D.

1974-01-01

The Secretary of the Interior has been requested to approve an exploration permit and mining lease which are part of a uranium exploration, mining, and milling Agreement, negotiated between the Navajo Tribe and the Exxon Corporation. The exploration area is a 400,000 acre tract located on the Navajo Reservation in San Juan County, New Mexico. If uranium ore in sufficient quantities to warrant development is discovered, Exxon is authorized to take a total of 51,200 acres to lease for mining, of which only 5,120 surface acres may be used for mining and milling purposes. While all exploration and predevelopment costs prior to mining must be borne by Exxon, the Navajo Tribe has reserved the right to participate in the venture on either a royalty basis or as a partner holding up to a 40 percent working interest. Impacts resulting from exploration will include disturbance of soils and vegetation and air quality degradation resulting from the vehicular movement and the operation of drilling equipment. If mining and milling takes place significant environmental impacts include: sub-surface water depletion, soils and vegetation disturbance, air quality degradation, interruption of the wildlife habitat, population increases, increased demands on community services and facilities, and disruption of established lifestyles and social patterns. Low levels of radioactive emissions will be found at mine and mill sites. Income and employment opportunities from the project to the Navajo Tribe, Navajo people, and the entire San Juan County community will be significant

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.

Hydrometallurgical Process and Kinetics of Leaching Manganese from Semi-Oxidized Manganese Ores with Sucrose

Directory of Open Access Journals (Sweden)

Yuhong Wang

2017-02-01

Full Text Available The extraction of manganese from a semi-oxidized manganese ore was investigated with sucrose as the reducing agent in dilute sulfuric acid medium. The kinetics of leaching manganese from the complex ore containing MnCO3 and MnO2 was also investigated. The effects of sucrose and sulfuric acid concentrations, leaching temperature and reaction time on the total Mn (TMn, MnO2 and MnCO3 leaching were investigated. Results showed that MnCO3 could more easily react with hydrogen ions than MnO2 in ores, and MnO2 decomposition could be advantageous for MnCO3 leaching. The leaching efficiencies of 91.8% for total Mn, 91.4% for MnO2 and 96.9% for MnCO3 were obtained under the following optimized conditions: 0.035 mol/L sucrose concentration, 5 mol/L sulfuric acid concentration, 60 min of reaction time and 363.2 K of leaching temperature. In addition, it was found that the leaching process of semi-oxidized manganese ore follows the shrinking core model and the leaching rate was controlled by chemical reaction and diffusion. The apparent activation energy of the total manganese, MnO2, and MnCO3 leaching were 40.83, 40.59, and 53.33 kJ·mol−1, respectively.

Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

International Nuclear Information System (INIS)

Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

2011-01-01

Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

Processing of low grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1978-10-01

Four types of low-grade ores are studied: (1) Low-grade ores that must be extracted because they are enclosed in a normal-grade deposit. Heap leaching is the processing method which is largely used. (2) Normal-grade ores contained in low-amplitude deposits. They can be processed using in-place leaching as far as the operation does not need any large and expensive equipment. (3) Medium-grade ores in medium-amplitude deposits. A simplified conventional process can be applied using fast heap leaching. (4) Low-grade ores in large deposits. The report explains processing possibilities leading in most cases to the use of in-place leaching. The operating conditions of this method are laid out, especially the selection of the leaching agents and the preparation of the ore deposit

Costs and benefits of alternatives for mill-tailings management: a perspective

International Nuclear Information System (INIS)

Chee, P.C.; Yuan, Y.C.; Roberts, C.J.

1983-01-01

Past milling of uranium and thorium ore in the United States has produced tailings that are stored at numerous sites around the country. Some of these storage sites are located near towns and cities, and the local populations are exposed to radiation and radioactive materials migrating off the sites. The federal government has initiated remedial action programs (for example the Uranium Mill Tailings Remedial Action Program and the Formerly Utilized Sites Remedial Action Program) to clean up land and buildings that have become contaminated with radioactive material and thus eliminate or reduce population exposure to radiation. The degree of long-term benefit from any reduction of the population dose will be different for each remedial action, as will the cost. To gain a perspective on the cost-benefit ratios of various alternatives (remedial actions), estimates are made of the potential radiation doses to affected populations near two inactive sites and of the costs associated with (1) onsite stabilization of radioactive tailings, and (2) transportation of tailings to remote locations for stabilization. The calculations presented in this paper were based on actual conditions at an inactive uranium mill tailings site (the Vitro site in Salt Lake City, Utah) and at a former thorium-processing facility (Kerr-McGee site in West Chicago, Illinois)

High-rate behaviour of iron ore pellet

Science.gov (United States)

Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

2015-09-01

Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

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)

Technological studies on the Manisa-Koprubasi uranium ores of Turkey

International Nuclear Information System (INIS)

Sagdik, U.

1980-01-01

At the end of the laboratory and pilot plant scale technological experiments, three main types of ore have been classified: (i) Kasar type: The ores consist of secondary uranium mineralization (autunite, meta-autunite and torbenite) in loosely consolidated sands, gravels and clays of Neogene Age. Heap leaching has been carried out on 100 and 1000 t ore samples (0.05% U 3 O 8 ) under economical conditions, such as 20 to 40 kg of H 2 SO 4 per tonne of ore at ambient temperature; original size -20 cm, solid/liquid ratio of 10, 20 days, and 90% recovery of uranium has been reached. The uraniferous solutions (1 to 2 g of U 3 O 8 per litre) obtained from the heap leaching operations were purified in a solvent extraction unit with a capacity of 100 ltr/h by using an Alamine 336-kerosene-decanol solution. The uranium in the purified and concentrated solutions (15 g of U 3 O 8 per litre) was then precipitated as a yellow cake with 65 to 75% U 3 O 8 content by means of magnesia milk. (ii) Tasharman type: No specific uranium mineral has been detected in the mineralogical determination, although uranium is disseminated in phosphate minerals as dahllite and apatite. Uranium in the ore has been leached under rather uneconomical conditions; 100 kg of H 2 SO 4 per tonne of ore, particle size -1 cm, 25 0 C, 30 days. In the SX-treatment of pregnant solutions phosphate ions, higher acidity than pH 1, and compounds formed as a chemical precipitation, hindered the SX-recoveries. In such cases, the addition of acid, dilution of pregnant solutions, membrane filtration, or 40 0 C temperature have been applied to decrease the uranium loss in the raffinate. (iii) Carbonate type: Even if alkaline leaching at 65 0 C, or leaching with 400 kg of H 2 SO 4 per tonne of ore, was carried out on -200 mesh ore samples, no acceptable uranium recoveries were obtained

Oxidizing attack process of uranium ore by a carbonated liquor

International Nuclear Information System (INIS)

Maurel, Pierre; Nicolas, Francois.

1981-01-01

A continuous process for digesting a uraniferous ore by oxidation with a recycling aqueous liquor containing alkaline carbonates and bicarbonates in solution as well as uranium in a concentration close to its solubility limit at digestion temperature, and of recuperation of the precipitated uranium within the solid phase remaining after digestion. The digestion is carried out by spraying oxygen into the hot reactional medium in order not only to permit oxidation of the uranium and its solubilization but also to ensure that the sulphides of impurities and organic substances present in the ore are oxidized [fr

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

Science.gov (United States)

Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

2016-10-01

With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

The applications of microwave energy to improve grindability and extraction of gold ores

Energy Technology Data Exchange (ETDEWEB)

Huang, J.H

2000-10-01

gold ore, in which gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37{approx}39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.5{approx}81.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional heating environment was also investigated. In a nitric acid solution, pyrite and marcasite can be rapidly leached. Reaction temperature and the concentration of HNO{sub 3} had a significant influence on decomposition rate. Marcasite had a substantially higher decomposition rate than pyrite. Microwave heating could promote the dissociation of marcasite and pyrite, compared with conventional heating. This was caused by special volumetric heating during microwave exposure that may induce local overheating or improve the interactions between the high dielectric loss minerals and the leaching solution. Kinetic investigations show that the decomposition of both the minerals in a nitric acid medium is controlled by chemical reactions on the surfaces of particles. The decomposition is a second order reaction with respect to nitric acid concentration. Less than 5 {approx} 7% of the decomposed sulphur was transformed into elemental sulphur during the leaching of both the minerals. (author)

The applications of microwave energy to improve grindability and extraction of gold ores

International Nuclear Information System (INIS)

Huang, J.H.

2000-10-01

gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37∼39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.5∼81.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional heating environment was also investigated. In a nitric acid solution, pyrite and marcasite can be rapidly leached. Reaction temperature and the concentration of HNO 3 had a significant influence on decomposition rate. Marcasite had a substantially higher decomposition rate than pyrite. Microwave heating could promote the dissociation of marcasite and pyrite, compared with conventional heating. This was caused by special volumetric heating during microwave exposure that may induce local overheating or improve the interactions between the high dielectric loss minerals and the leaching solution. Kinetic investigations show that the decomposition of both the minerals in a nitric acid medium is controlled by chemical reactions on the surfaces of particles. The decomposition is a second order reaction with respect to nitric acid concentration. Less than 5 ∼ 7% of the decomposed sulphur was transformed into elemental sulphur during the leaching of both the minerals. (author)

The flotation of Roşia Poieni copper ore in column machine, with non-polar oils addition

Directory of Open Access Journals (Sweden)

Ciocani V.

2005-11-01

Full Text Available The most important natural resource of copper in Romania is the ore deposit of Roşia Poieni. At present, the utilization of Roşia Poieni poorphyry copper ore is possible by extraction in quarry of the mass ore and mineral processing into a technological flux with modest results for the value of metal recovery in concentrate 70-72 % and an average contents of 16,5 % Cu. Our researches were directed to studies regarding test and utilisation of special procedure of flotation – addition of the non-polar oil – applied to advanced grinding ore with column type machines.

Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site.

Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

International Nuclear Information System (INIS)

1994-09-01

This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site

Measurement and calculation of radon releases from uranium mill tailings

International Nuclear Information System (INIS)

1992-01-01

The mining and milling of uranium ores produces large quantities of radioactive wastes. Although relatively small in magnitude compared to tailings from metal mining and extraction processes, the present worldwide production of such tailings exceeds 20 million tonnes annually. There is thus a need to ensure that the environmental and health risks from these materials are reduced to an acceptable level. This report has been written as a complement to another publication entitled Current Practices for the Management and Confinement of Uranium Mill Tailings, IAEA Technical Reports Series No. 335, which provides a general overview of all the important factors in the siting, design and construction of tailings impoundments, and in the overall management of tailings with due consideration give to questions of the release of pollutants from tailings piles. The present report provides a comprehensive overview of the release, control and monitoring of radon, including computational methods. The report was first drafted in 1989 and was then reviewed at an Advisory Group meeting in 1990. 42 refs, 9 figs, 3 tabs

Lacustrine-humate model for primary uranium ore deposits, Grants Uranium Region, New Mexico

International Nuclear Information System (INIS)

Turner-Peterson, C.E.

1985-01-01

Two generations of uranium ore, primary and redistributed, occur in fluvial sandstones of the Upper Jurassic Morrison Formation in the San Juan basin; the two stages of ore formation can be related to the hydrologic history of the basin. Primary ore formed soon after Morrison deposition, in the Late Jurassic to Early Cretaceous, and a model, the lacustrine-humate model, is offered that views primary mineralization as a diagenetic event related to early pore fluid evolution. The basic premise is that the humate, a pore-filling organic material closely associated with primary ore, originated as humic acids dissolved in pore waters of greenish-gray lacustrine mudstones deposited in the mud-flat facies of the Brushy Basin Member and similar K shale beds in the Westwater Canyon Member. During compaction associated with early burial, formation water expelled from lacustrine mudstone units carried these humic acids into adjacent sandstone beds where the organics precipitated, forming the humate deposits that concentrated uranium. During the Tertiary, much later in the hydrologic history of the basin, when Jurassic sediments were largely compacted, oxygenated ground water flowed basinward from uplifted basin margins. This invasion of Morrison sandstone beds by oxidizing ground waters redistributed uranium from primary ores along redox boundaries, forming ore deposits that resemble roll-front-type uranium ores. 11 figures

Geochemical features of the ore-bearing medium in uranium deposits in the Khiagda ore field

Science.gov (United States)

Kochkin, B. T.; Solodov, I. N.; Ganina, N. I.; Rekun, M. L.; Tarasov, N. N.; Shugina, G. A.; Shulik, L. S.

2017-09-01

The Neogene uranium deposits of the Khiagda ore field (KOF) belong to the paleovalley variety of the hydrogene type and differ from other deposits of this genetic type in the geological and geochemical localization conditions. The contemporary hydrogeochemical setting and microbiological composition of ore-bearing medium are discussed. The redox potential of the medium (Eh is as low as-400 mV) is much lower than those established at other hydrogenic deposits, both ancient Late Mesozoic and young Late Alpine, studied with the same methods in Russia, Uzbekistan, and southern Kazakhstan. The pH of subsurface water (6.86-8.13) differs in significant fluctuations both between neighboring deposits and within individual ore lodes. Hydrogen-forming and denitrifying bacteria are predominant in microbiological populations, whereas sulfate-reducing bacteria are low-active. The consideration of these factors allowed us to describe the mechanism of uranium ore conservation as resulting from the development of the cryolithic zone, which isolates ore lodes from the effect of the external medium. Carbonated water supplied from the basement along fault zones also participates in the formation of the present-day hydrogeochemical setting. Based on the features of the ore-bearing medium, we propose a method of borehole in situ acid leaching to increase the efficiency of mining in the Khiagda ore field.

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

Grouting of uranium mill tailings piles

International Nuclear Information System (INIS)

Boegly, W.J. Jr.; Tamura, T.; Williams, J.D.

1984-03-01

A program of remedial action was initiated for a number of inactive uranium mill tailings piles. These piles result from mining and processing of uranium ores to meet the nation's defense and nuclear power needs and represent a potential hazard to health and the environment. Possible remedial actions include the application of covers to reduce radon emissions and airborne transport of the tailings, liners to prevent groundwater contamination by leachates from the piles, physical or chemical stabilization of the tailings, or moving the piles to remote locations. Conventional installation of liners would require excavation of the piles to emplace the liner; however, utilization of grouting techniques, such as those used in civil engineering to stabilize soils, might be a potential method of producing a liner without excavation. Laboratory studies on groutability of uranium mill tailings were conducted using samples from three abandoned piles and employing a number of particulate and chemical grouts. These studies indicate that it is possible to alter the permeability of the tailings from ambient values of 10 -3 cm/s to values approaching 10 -7 cm/s using silicate grouts and to 10 -8 cm/s using acrylamide and acrylate grouts. An evaluation of grouting techniques, equipment required, and costs associated with grouting were also conducted and are presented. 10 references, 1 table

Zeolitization at uranium ore manifestation

International Nuclear Information System (INIS)

Petrosyan, R.V.; Buntikova, A.F.

1981-01-01

The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

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.

Finding and evaluating potential radiological problems in the vicinity of uranium milling sites

International Nuclear Information System (INIS)

Goldsmith, W.A.; Yates, W.G.

1982-01-01

The Oak Ridge National Laboratory (ORNL) has been performing radiological surveys at former uranium and thorium milling and processing sites since 1975. Tailings at inactive milling sites usually have a low frequency of human occupancy but continuously generate 222 Rn into the atmosphere. Thus, independent 222 Rn surveys are conducted at the inactive mill sites and their environs by the Mound Facility. Measurements of airborne 222 Rn and 222 Rn flux are made on the sites to define the tailings source term. Concurrently with these measurements, an ambient 222 Rn monitoring network is established off-site and a meteorological station is established at or near the mill site. Unfortunately, tailings are not always confined to the milling site. Radioactivity can migrate to areas outside of site boundaries by wind and water erosion, groundwater transport, spillage of incoming ore, and removal of tailings or other material for private purposes. In order to identify and assess off-site radioactivity on properties in the vicinity of milling sites, a combination of aerial and ground-level radiological monitoring techniques are used. The ground mobile gamma-ray scan is conducted using a vehicle equipped with sensitive gamma-ray detectors. The detectors are shielded so that gamma radiation input is viewed through only one side of the vehicle. This system is capable of precisely locating properties which have anomalously high gamma radiation levels caused by the presence of tailings. Subsequently, these properties are identified as candidate vicinity properties and are scheduled for radiological surveys subject to the property owner's consent. The comprehensive radiological surveys conducted at these vicinity properties determine the amount, type, and location of tailings materials

Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

International Nuclear Information System (INIS)

Corrans, I.J.; Levin, J.

1979-01-01

Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20μm. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed [af

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

Control of As and Ni releases from a uranium mill tailings neutralization circuit: Solution chemistry, mineralogy and geochemical modeling of laboratory study results

Energy Technology Data Exchange (ETDEWEB)

Mahoney, John [MWH Americas, Inc., 1801 California Street, Denver, CO 80202 (United States)], E-mail: john.j.mahoney@mwhglobal.com; Slaughter, Maynard [Earth Science, University of Northern Colorado, Greeley, CO 80639 (United States); Langmuir, Donald [Hydrochem Systems Corp., P.O. Box 23257, Silverthorne, CO 80498 (United States); Rowson, John [AREVA Resources Canada Inc., P.O. Box 9204, Saskatoon, SK, S7K 3X5 (Canada)

2007-12-15

Processing U ores in the JEB Mill of the McClean Lake Operation in northern Saskatchewan produces spent leaching solutions (raffinates) with pH {<=} 1.5, and As and Ni concentrations up to 6800 and 5200 mg L{sup -1}, respectively. Bench-scale neutralization experiments (pH 2-8) were performed to help optimize the design of mill processes for reducing As and Ni concentrations in tailings and raffinates to {<=}1 mg L{sup -1} prior to their disposal. Precipitate mineralogy determined by chemical analysis, XRD, SEM, EM, XM and EXAFS methods, included gypsum (the dominant precipitate), poorly crystalline scorodite (precipitated esp. from pH 2-4), annabergite, hydrobasaluminite, ferrihydrite, green rust II and theophrastite. The As was mostly in scorodite with smaller amounts in annabergite and trace As adsorbed and/or co-precipitated, probably by ferrihydrite. Geochemical modeling indicated that above pH 2, the ion activity product (IAP) of scorodite lies between the solubility products of amorphous and crystalline phases (log K{sub sp} = -23.0 and -25.83, respectively). The IAP decreases with increasing pH, suggesting that the crystallinity of the scorodite increases with pH. Forward geochemical models support the assumption that during neutralization, particles of added base produce sharp local pH gradients and disequilibrium with bulk solutions, facilitating annabergite and theophrastite precipitation.

The source of groundwater and solutes to Many Devils Wash at a former uranium mill site in Shiprock, New Mexico

Science.gov (United States)

Robertson, Andrew J.; Ranalli, Anthony J.; Austin, Stephen A.; Lawlis, Bryan R.

2016-04-21

The Shiprock Disposal Site is the location of the former Navajo Mill (Mill), a uranium ore-processing facility, located on a terrace overlooking the San Juan River in the town of Shiprock, New Mexico. Following the closure of the Mill, all tailings and associated materials were encapsulated in a disposal cell built on top of the former Mill and tailings piles. The milling operations, conducted at the site from 1954 to 1968, created radioactive tailings and process-related wastes that are now found in the groundwater. Elevated concentrations of constituents of concern—ammonium, manganese, nitrate, selenium, strontium, sulfate, and uranium—have also been measured in groundwater seeps in the nearby Many Devils Wash arroyo, leading to the inference that these constituents originated from the Mill. These constituents have also been reported in groundwater that is associated with Mancos Shale, the bedrock that underlies the site. The objective of this report is to increase understanding of the source of water and solutes to the groundwater beneath Many Devils Wash and to establish the background concentrations for groundwater that is in contact with the Mancos Shale at the site. This report presents evidence on three working hypotheses: (1) the water and solutes in Many Devils Wash originated from the operations at the former Mill, (2) groundwater in deep aquifers is upwelling under artesian pressure to recharge the shallow groundwater beneath Many Devils Wash, and (3) the groundwater beneath Many Devils Wash originates as precipitation that infiltrates into the shallow aquifer system and discharges to Many Devils Wash in a series of springs on the east side of the wash. The solute concentrations in the shallow groundwater of Many Devils Wash would result from the interaction of the water and the Mancos Shale if the source of water was upwelling from deep aquifers or precipitation.In order to compare the groundwater from various wells to groundwater that has been

Finding of No Significant Impact, proposed remediation of the Maybell Uranium Mill Processing Site, Maybell, Colorado

International Nuclear Information System (INIS)

1995-01-01

The U.S. Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-0347) on the proposed surface remediation of the Maybell uranium mill processing site in Moffat County, Colorado. The mill site contains radioactively contaminated materials from processing uranium ore that would be stabilized in place at the existing tailings pile location. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, Public Law 91-190 (42 U.S.C. section 4321 et seq.), as amended. Therefore, preparation of an environmental impact statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI)

[Biooxidation of gold-bearing sulfide ore and subsequent biological treatment of cyanidation residues].

Science.gov (United States)

Kanaev, A T; Bulaev, A G; Semenchenko, G V; Kanaeva, Z K; Shilmanova, A A

2016-01-01

The percolation biooxidation parameters of ore from the Bakyrchik deposit were studied. An investigation of the technological parameters (such as the concentration of leaching agents, irrigation intensity, and pauses at various stages of the leaching) revealed the optimal mode for precious metal extraction. The stages of the ore processing were biooxidation, gold extraction by cyanidation or thiosulfate leaching, and biological destruction of cyanide. The gold and silver recovery rates by cyanidation were 64.0 and 57.3%, respectively. The gold and silver recovery rates by thiosulfate leaching were 64.0 and 57.3%, respectively. Gold and silver recovery rates from unoxidized ore (control experiment) by cyanidation were 20.9 and 26.8%, respectively. Thiosulfate leaching of unoxidized ore allowed the extraction of 38.8 and 24.2% of the gold and silver, respectively. Cyanidation residues were treated with bacteria of the genus Alcaligenes in order to destruct cyanide.

Pulp-mill related polychlorinated organic compounds in Baltic Sea sediments

Energy Technology Data Exchange (ETDEWEB)

Jonsson, Per (Swedish Environmental Protection Agency, Solna (Sweden)); Rappe, C.; Kjeller, L.O. (Umeaa Univ. (Sweden). Inst. of Environmental Chemistry); Kierkegaard, A. (Stockholm Univ. (Sweden). Inst. of Applied Environmental Research); Haakansson, L. (Uppsala Univ. (Sweden). Inst. of Earth Sciences); Jonsson, Bjoern (County Adm. Board, Umeaa (Sweden))

1993-01-01

Sediment samples from the Baltic basin were analyzed for PCDD/Fs, alkyl-CDFs, chloroguaiacols and EOCl. The EOCl distribution pattern in the Iggesund pulp-mill area shows high sediment concentrations close to the mill, and decreasing concentrations with increasing distance from the mill. Two series of alkyl-CDFs have been identified. The PCDD/Fs in offshore surficial sediments from the Baltic proper show a typical incineration pattern, while sediments collected in the vicinity of the mill show enhanced levels of 2,3,7,8-tetraCDD, 2,3,7,8- and 1,2,7,8-tetraCDF, and 1,2,3,7,8-pentaCDD. These PCDD/F congeners are statistically correlated to di-, tri-, and tetrachloroguaiacols, alkyl-CDFs, EOCl, and to the distance from the pulp mill, indicating the same source and transportation regime. Principal component analysis of the data set supports this conclusion. The three 2,3,7,8-tetrachloro-substituted PCDD/F congeners have formerly been found in high concentrations in sediments and crab hepatopancreas close to a pulp mill on the Swedish west coast. Our results from a pulp mill on the Swedish east coast support the conclusion that these congeners are typically associated with pulp bleaching. Deep layer sediments have significantly lower levels of PCDD/Fs. The isomer profiles are different in the surficial and the deep sediments, indicating a more natural preindustrial production of PCDD/Fs. (53 refs., 7 figs.).

Technological pretreatment of the synchysite non-oxidized ore

Science.gov (United States)

Munkhtsetseg, B.; Burmaa, G.

2013-06-01

Mongolia has rich deposits of rare, precious, and poly-metallic ores. Nowadays, it is important to research separation of rare earth elements oxides concentrates from the ores, analyze their unique physical chemical characteristics, and purified it. Our investigation on raw materials focuses on rare earth non-oxidized ores. Main mineral in this rock sample is Synchysite (LnCa(CO3)2F. We did technological and thermal pretreatment: direct sulphurization (H2SO4), sulphurization with subsequent roasting (800°C+H2SO4), sulphurization prior to roasting (H2SO4+650°C). Sulphurization method based on dissolution of rare earth mineral into sulfuric acid (93%) according to the reaction. The amount of rare earth element oxides is almost 10 times greater (29.16%) after direct sulphurization process, almost 8 times greater (21.14%) after sulphurization with subsequent roasting, and almost 20 times greater (44.62%) after sulphurization prior to roasting process. After those technological pretreatment raw material's micro elements Thorium and Uranium contents are reduced as follows: H2SO4>800°C+H2SO4>H2SO4+650°C. These results show that cerium group rare earth elements have very good solubility in water at +2°C temperature and decreasing micro elements content uranium and thorium good pretreatment condition is prior to roasting (H2SO4+650°C) of synchysite non-oxidized ore.

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)

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

; and potential ore, material likely to become usable under more favorable conditions. The tonnage and grade of material of combined reserves and potential ore in each of the deposits known or believed to contain at least 200,000 long tons of iron-ore resources are tabulated in this report, and numerous sources of additional information are given in a selected bibliography. The total domestic iron-ore resources are estimated at approximately 75,000 million long tons of crude ore. About 10,000 million tons of the resources is reserves of crude ore that will probably yield 5,500 million tons of concentrates and direct-shipping ore. About 65,000 million tons is potential ore and may yield 25,000 million tons of concentrates and some direct-shipping ore.

Ore loses and dilution of the ore vein no. 4 in the Zletovo mine, Republic of Macedonia

Directory of Open Access Journals (Sweden)

Bogatinovski Nikola L.

2017-01-01

Full Text Available Zletovo mines have a tradition of exploration and exploitation of vein lead-zinc ores for almost a century. Ore losses and dilutions have always been imperative in production since traditional old methods of mining and low-productivity mineralization are used. In conditions of classical and sub-level method excavations used, the calculated ore losses in ore vein No. 4 are 13.5%, while at the level of all excavations in the Zletovo mines dilution averages at 10%. Ore dilution is also an important technical parameter and several possible variants were calculated. When analyzing the dilution that occurs during the preparation of the sub-level corridor with parameters such: different drop angle (45-60o, constant thickness of 1.47 m as the average vein thickness in the calculated ore reserves, width of the sub-level corridor of 1.57 m or to the width of the ore vein No. 4 were added 10 cm (left and right to 5 cm as much as is taken in the calculation of the planned dilution and height of 2.5 m as suggested for this mining method, it can be noticed that the planned dilution during this method of mining ranges from 26.3% to 42.3%. In conditions of use of this underground method of excavation, parameters are selected that allow for the indicated lowering of the dilution. Namely, the thickness of the ore wire would be 1.47 m, the mining width would be 1.57 m, only 10 cm (left and right up to 5cm to the thickness of the ore vein will be added, the height difference between the consecutive levels would be 7.5 m, dip angle of 45 to 60°, and with the excavation the whole ore vein would be covered in height. On the basis of these parameters, models were prepared in which the ore vein would have a different dip angle, from which the values for the planned ore dilution ranged from 6.7 to 7.8%, which is significantly lower than the average dilution in the Zletovo Mine.

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

Geochemical investigation of UMTRAP designated site at Canonsburg, Pennsylvania

International Nuclear Information System (INIS)

Markos, G.; Bush, K.J.; Freeman, T.

1981-05-01

UMTRAP is an acronym for Uranium Mill Tailings Remedial Action Project. The Canonsburg, Pennsylvania site was utilized from 1911 to 1922 and from 1930 to 1942, first to remove radium from sedimentary uranium ore, and later to remove uranium from ore as well as process various materials, ceasing operations in 1957. Of the three areas, Area A is the former mill site and is occupied in part by present industrial activities. Area B is comprised of mill residues mixed with sediment dredged from Chartiers Creek, a disturbed terrace along Chartiers Creek, and a ditch on the north side. The ditch contains water with the highest concentrations of contaminants measured in the Canonsburg site. It is believed that unprocessed ore is deposited here and effluent from leaks in a sewer line across the north edge of Areas A and B carry contaminants from heavily contaminated drains in the buildings of Area A. Area C contains the former liquid disposal lagoon, and the central part of the area is highly contaminated to a depth of about 3 meters. Area C contains the most concentrated waste material with maximum levels (except for the ditch on the north side of Area B) of all the contaminants distributed throughout the area. Contamination outside the site is limited. The presence of contaminants in the ditches, in the soils on the river bank, and below the tailings pile is not attributed to migration processes, but rather to the presence of ore materials and concentrated wastes mechanically dispersed throughout the area

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)

Mining, ore preparation and niobium alloys production at Araxa, Brazil

International Nuclear Information System (INIS)

Paraiso, O.S.; Fuccio Junior, R. de; Betz, E.W.

1984-01-01

A detailed description of the worlds major niobium producer is presented covering mining, concentration by froth flotation, leaching, and production of ferro-alloys. The present exploration of the Araxa deposit, its ore preparation and production of ferro-niobium is described. (E.G.) [pt

Uranium and Molybdenum extraction from a Cerro Solo deposit ore

International Nuclear Information System (INIS)

Becquart, Elena T.; Arias, Maria J.; Fuente, Juan C. de la; Misischia, Yamila A.; Santa Cruz, Daniel E.; Tomellini, Guido C.

2009-01-01

Cerro Solo, located in Chubut, Argentina, is a sandstone type uranium-molybdenum deposit. Good recovery of both elements can be achieved by acid leaching of the ore but the presence of molybdenum in pregnant liquors is an inconvenient to uranium separation and purification. A two steps process is developed. A selective alkaline leaching of the ore with sodium hydroxide allows separating and recovering of molybdenum and after solid-liquid separation, the ore is acid leached to recover uranium. Several samples averaging 0,2% uranium and 0,1% molybdenum with variable U/Mo ratio have been used and in both steps, leaching and oxidant reagents concentration, temperature and residence time in a stirred tank leaching have been studied. In alkaline leaching molybdenum recoveries greater than 96% are achieved, with 1% uranium extraction. In acid leaching up to 93% of the uranium is extracted and Mo/U ratio in solvent extraction feed is between 0,013 and 0,025. (author)

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Lakeview, Oregon. Revision 2

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the UMTRA Project site near Lakeview, Oregon, was completed in 1989. The mill operated from February 1958 to November 1960. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.

Enhancement of Cu, Ni and Mo recoveries in the bulk concentrate of Jaduguda uranium bearing ore

International Nuclear Information System (INIS)

Rao, G.V.; Besra, L.D.

1998-01-01

The uranium ore treatment plant at Jaduguda, India, recovers copper, nickel and molybdenum as byproducts before the bulk flotation tailings are subjected to leaching to recover uranium values. The recoveries of these sulfide metals in this 900 TPD plant are reported to be around 60 % Cu, 25% Ni and 55% Mo in the bulk concentrate. In this article, flotation studies carried out, at the instance of M/S UCIL, with various reagents and their combination to improve the over all recoveries are presented. It was observed that material coarser than 100 microns, from the flotation feed, could not be floated even in presence of excessive reagent unless it is ground further. It was established that around 95% Cu, 75% Ni and 74% Mo values could be recovered by using either amyl xanthate or mixture of amyl xanthate and Aero Promoter 194 in place of cresylic acid that is being currently used as collector in the plant. (author)

Rirang Uranium Ore Processing System Design: Agitated Digester

International Nuclear Information System (INIS)

Erni, R.A.; Susilaningtyas

1996-01-01

A closed tank digester equipped with a pitched blades turbine agitator has been designed to facilities Rirang uranium ore dissolution using concentrated sulphuric acid at high temperature. The digester was designed to accommodate the digestion of 6 kg of-65 mesh ore at 200 o C, acid resistant material (SS-3 16). It has the dimension of 33 cm high, 22 cm diameter, and elliptical bottom and height of 4 cm. Moreover, the dimension of the 4 blades agitator is as follows: 8 cm long, 1,6 cm blades width. The distance between the blades and digester required 0, 007 Hp for a 500 rpm agitation speed and + 24. 103 kcal energy equipment for heating. Digestion experiment using the agitated digester yielded data that are in good agreement with laboratory scale experiment

Preconcentration of low-grade uranium ores with environmentally acceptable tailings, part I

International Nuclear Information System (INIS)

Raicevic, D.; Raicevic, M.; McCarthy, D.R.

1979-08-01

The low-grade ore sample used for this investigation originated from Agnew Lake Mines Limited, Espanola, Ontario. It contained about 1% pyrite and 0.057% uranium, mainly as uranothorite with a small amount of brannerite. Both of these minerals occur in the quartz-sericite matrix of a conglomerate. A preconcentration process has been developed to give a high uranium recovery, reject pyrite, radium and thorium from the ore and produce environmentally acceptable tailings. This process applies flotation in combination with high intensity magnetic separation and gravity concentration

Surface modification and column flotation of a massive ilmenite ore

International Nuclear Information System (INIS)

Fan, X.; Rowson, N.A.

2002-01-01

The main problems with ilmenite flotation in impeller-type flotation machines are the poor flotation behaviour of ilmenite and the negative effect of slimes. These cause high ilmenite losses in tailings even when a large dosage of fatty acid and fuel oil is consumed. In this study, microwave radiation pre-treatment and ilmenite surface activation were used to modify the surface properties of a massive ilmenite ore sample from Norway to improve ilmenite flotability. A column cell was used to minimize the negative effect of slimes on ilmenite separation efficiency. When ilmenite flotation was performed in a 1 litre Denver cell, the flotation recovery of titanium dioxide from the ilmenite ore sample was only 68.5% (31.1% TiO 2 ) under conventional flotation conditions. After microwave radiation pre-treatment for three minutes at 2600 W and 2.45 GHz, the ferrous ions on ilmenite particle surfaces were converted into ferric ions; hence, the recovery increased from 68.5% to 86.8%. The concentrate grade increased from 31.1% TiO 2 to 32.1% TiO 2 . In ilmenite activation flotation, Pb 2+ ions can be selectively adsorbed on to ilmenite particle surfaces as active sites and therefore enhance the adsorption of oleate ions on ilmenite surfaces. With the addition of 60 g/ton Pb(NO 3 ) 2 , ilmenite flotation recovery increased from 68.5% to 85.1%. However, the quality of ilmenite concentrates was not improved due to the negative effect of slimes. After a two stage cleaning, the grade of ilmenite concentrates was only about 31% TiO 2 . The combination of microwave radiation pre-treatment and the application of a column cell overcame both problems of poor flotability and the negative effect of slimes. When the Denver cell was replaced by a column cell and the massive ilmenite ore sample was pre-treated using microwave radiation for three minutes, the ilmenite concentrate grade increased from 31.1% TiO 2 to 42.9% TiO 2 and the titanium dioxide recovery increased from 68.5% to 90

Discussion on prospecting potential for rich uranium deposits in Xiazhuang uranium ore-field, northern Guangdong

International Nuclear Information System (INIS)

Wu Lieqin; Tan Zhengzhong

2004-01-01

Based on analyzing the prospecting potential for uranium deposits in Xiazhuang uranium ore field this paper discusses the prospecting for rich uranium deposits and prospecting potential in the region. Research achievements indicate: that the Xiazhuang ore-field is an ore-concentrated area where uranium has been highly enriched, and possesses good prospecting potential and perspective, becoming one of the most important prospecting areas for locating rich uranium deposits in northern Guangdong; that the 'intersection type', the alkaline metasomatic fractured rock type and the vein-group type uranium deposits are main targets and the prospecting direction for future uranium prospecting in this region

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

Regulatory view of the close-out of the uranium ore mine Zirovski Vrh

International Nuclear Information System (INIS)

Vrankar, L.

2005-01-01

The production of the uranium mine Zirovski Vrh ceased in 1990. The main remaining problem of the remadiation are mine and mill tailings. The uranium mine Zirovski Vrh has one mill tailings site Borst and one waste pile Jazbec. According to the Act on protection against ionising radiation and nuclear safety which was adopted by the Parliament in 2002, they are classified as radiation facilities. Slovenian Nuclear Safety Administration (SNSA) is authorised for issuing a mandatory consent to mining work. The SNSA prepared the initial proposal of content of the safety report for the mine waste pile Jazbec. In 2005, according to the detailed content of this document, the public company Zirovski Vrh Ltd prepared the safety report which was examined by an authorised expert for radiation and nuclear safety. After a careful revision of the safety evaluation report, the consensus for mining work shall be issued by the SNSA. After finishing the mining works the SNSA shall also issue a licence for the closure of waste pile Jazbec. The main goal of this article is to present the Slovenian regulations which cover also mining work in the field of close-out of the uranium ore mine. (author)

Flotation-nitric acid leach procedure for increasing uranium recovery from a refractory ore

International Nuclear Information System (INIS)

Carnahan, T.G.; Lei, K.P.V.

1979-01-01

The Bureau of Mines investigated a flotation-nitric acid leach procedure as part of the goal to maximize minerals and metals recovered from primary and secondary domestic resources. Studies were conducted on an ore that contained carbon-bearing and sulfide mineralization that rendered a portion of the ore refractory (resistant) to conventional leaching technology. The procedure investigated for treating the ore consisted of the following: (1) separation by flotation of the carbonaceous and sulfidic components from the ore, (2) leaching the flotation concentrate with nitric acid at 100 0 to 110 0 C, (3) leaching the flotation tailings with sulfuric acid, and (4) processing the combined leached slurries in a conventional manner to recover yellow cake. In step 2, HNO 3 is converted to gaseous products from which it is regenerated by reacting these products with air and water for further leaching. An overall uranium extraction of 96% was achieved by this procedure

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

Microbial leaching of low grade copper ores

International Nuclear Information System (INIS)

Rauf, A.; Ashfaq, M.

1991-01-01

Biotechnology is regarded as one of the most promising and revolutionary solution to various problems which are generally faced in the extraction of metals from their ores such as high energy, capital costs and environmental pollution. The paper deals with the study of low grade copper ores for their beneficiation and extraction of copper. The ores used were chalcopyrite and oxidized copper ores. Microorganisms play a vital role in the solubilization of valuable contents from ores such as copper and other metals. Studies have been conducted on the indigenous copper ores by using thiobacillus ferro oxidans and thiobacillus thio oxidans. For comparison purpose some experiments have also been conducted by chemical leaching. The results of bacterial leaching are encouraging. (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 role of magmas in the formation of hydrothermal ore deposits

Science.gov (United States)

Hedenquist, Jeffrey W.; Lowenstern, Jacob B.

1994-01-01

Magmatic fluids, both vapour and hypersaline liquid, are a primary source of many components in hydrothermal ore deposits formed in volcanic arcs. These components, including metals and their ligands, become concentrated in magmas in various ways from various sources, including subducted oceanic crust. Leaching of rocks also contributes components to the hydrothermal fluid—a process enhanced where acid magmatic vapours are absorbed by deeply circulating meteoric waters. Advances in understanding the hydrothermal systems that formed these ore deposits have come from the study of their active equivalents, represented at the surface by hot springs and volcanic fumaroles.

Assessment of heavy metals introduced into food through milling process: health implications

International Nuclear Information System (INIS)

Adeti, P.J.

2015-07-01

The present study was conducted to characterised and assesss heavy metal contamination in food through milling process and their health implications. Grinding plate made from Ghana, India and Nigeria purchased from the Ghanaian open market were used for this work. Maize from the same farm was milled into flour using the three grinding plate inserted into three different corn milling machines operating on commercial bases. Th first grinding was done immediately after the insertion of the newly sharpened plates into the machines. The plates were left for continuous daily usage. Subsequent milling of the maize was done after intervals of one month. The grinding plates and maize flour was analysed using Atomic absorption spectrophometer (AAS). The resultes recorded indicated that the heavy metals content o the Ghanaian, Indian and Nigerian made plates had the e similar metal contents but varied in terms of the individual metal concentrations. Flour from the Ghanaian made plates had the highest level of contaminants with the least from that of the Indian made plates. Generally, the highest levels of contamination were observed in the fist milling for the three plates as compared to the three subsequent milling at monthly interval. The contamination levels showed a decreasing trend from the first month (first milling ) to the fourth month (fourth milling). Cu, Cr and Ni showed concentrations above the permissible limit set by FAO/WHO in milled maize using Ghanaian made plate. Copper (Cu) recorded a concentration value between 15.04 mg/kg to 10.21mg.kg, 11.25 mg/kg to 9.13mg/kg and 10.36mg/kg and 9.68mg/kg using the Ghanaian-, Indian and Nigerian made plate respectively. Chromium (Cr) recorded a concentration between 1.51 mg/kg to 0.96 mg/kg, 1.03mg/kg to 0.91 mg/kg and 0.98mg/kg to 0.80 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. Nickel (Ni) recorded a concentration value between 23.23 mg/kg to 10.43 mg/kg, 11.46mg/kg to 10.43 mg/kg and 12.55 mg

Chlorine/chloride based processes for uranium ores

International Nuclear Information System (INIS)

1980-11-01

The CE Lummus Minerals Division was commissioned by The Department of Supply and Services to develop order-of-magnitude capital and operating cost estimates for chlorine/chloride-based processes for uranium ores. The processes are designed to remove substantially all radioactive consituents from the ores to render the waste products harmless. Two processes were selected, one for a typical low grade ore (2 lb. U 3 O 8 /ton ore) and one for a high grade ore (50 lbs U 3 O 8 /ton). For the low grade ore a hydrochloric acid leaching process was chosen. For high grade ore, a more complex process, including gaseous chlorination, was selected. Capital cost estimates were compiled from information obtained from vendors for the specified equipment. Building cost estimates and the piping, electrical and instrumentation costs were developed from the plant layout. Utility diagrams and mass balances were used for estimating utilities and consumables. Detailed descriptions of the bases for capital and operating cost estimates are given

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.)

Radionuclides release to three rivers by ore treatment unit at Caldas, Minas Gerais - Brazil

International Nuclear Information System (INIS)

Pereira, W.S.; Carmo, R.F. do; Py Junior, D.A.

2013-01-01

The Ore Treatment Unit (OTU) is a uranium mining and milling plant, situated at Caldas city, Minas Gerais, Brazil that was disabled in the mid 90's. This unit releases controlled effluents to three rivers: Ribeirao das Antas (at point 014, influenced by the waste pile), Ribeirao Soberbo (point 025, influenced by the waste pond) and Corrego da Consulta (at point 076, influenced by the open pit mine). Water samples collected at these points were analyzed for U nat , 226 Ra, 210 Pb, 232 Th and 228 Ra content in the particulate and soluble fractions, and the behavior of radionuclide releases and their fractions was investigated. U nat and 228 Ra showed identical behaviors at these three points. U nat at point 014 (waste pile) behaved different from described in recent literature data. The isotopes of Ra should exhibit the same behavior at each point, but this was not observed at point 025 (waste pond). 232 Th release showed equal activity concentration near the waste pile (point 014) and near the waste pond (point 025), whilst near the open pit mine (point 076) the soluble fraction showed a concentration of activity greater than the particulate fraction. Finally, 210 Pb showed a different behavior at each point. Due to the great differences in behaviors of each radionuclide, it was not possible to establish a temporal pattern of release which requires assessment over a longer period of time. (author)

Complexing and hydrothermal ore deposition

CERN Document Server

Helgeson, Harold C

1964-01-01

Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

International Nuclear Information System (INIS)

Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

2012-01-01

It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

Characterization and Separation Studies of a Fine Sedimentary Phosphate Ore Slime

Directory of Open Access Journals (Sweden)

Xin Liu

2017-06-01

Full Text Available Detailed characterization and recovery of apatite from a sedimentary phosphate ore slime of a gravity plant of Yichang, China, were investigated. The phosphate ore slime consisted mainly of apatite, quartz, dolomite, and clay. To start with, the ore slime was characterized in sufficient detail to reveal that it is extremely fine in distribution with a d50 of 65 μm. Other different characterizations, such as apatite grain size distribution, apatite liberation, particle density distribution, and theoretical grade recovery, were also analyzed by mineral liberation analyser (MLA. Based on the results, a new gravity-flotation process, which was comprised of spiral gravity and reverse flotation, was proposed to process the slime. In the new process, the apatite was firstly recovered by two-stage spiral gravity, avoiding direct flotation. The gravity concentrate was the feed for the reverse flotation. A phosphate concentrate of 30.51% P2O5 with a P2O5 recovery of 89.00% can be produced from the slime analyzing 24.25% P2O5. Compared to the conventional direct-reverse flotation process, it was found that the reagent cost of the new gravity-flotation process was lower a quarter than that of the direct-reverse flotation flowsheet.

Concentrations and biological availability of 238U and 230Th in the environs of a uranium milling operation

International Nuclear Information System (INIS)

Ibrahim, S.; Flot, S.; Whicker, F.W.

1982-01-01

This paper reports on a study whose objectives were to determine 238 U and 230 Th concentrations in soil and native plants from various sites around a conventional acid leach uranium milling operation in the Western US, and to estimate plant/soil concentration factors. Soil and vegetation samples were collected from exposed, weathered tailings; near the edge of a tailings pond; from a reclamation area; and at several native range background (control) locations. The results indicate that mean plant/soil concentration factors varied significantly among sites and between radionuclides, but no significant differences between plant groups were found. Concentration factors for 230 Th were greater than for 238 U for plants growing at the edge of the tailings pond. It is speculated that the lower concentration factors for uranium relative to thorium at this site may be due to the proportion of their contents in soil that is biologically available for plant uptake

McClean Lake. Site Guide

International Nuclear Information System (INIS)

2016-09-01

Located over 700 kilometers northeast of Saskatoon, Areva's McClean Lake site is comprised of several uranium mines and one of the most technologically advanced uranium mills in the world - the only mill designed to process high-grade uranium ore without dilution. Areva has operated several open-pit uranium mines at the McClean Lake site, and is evaluating future mines at and near the site. The McClean Lake mill has recently undergone a multimillion-dollar upgrade and expansion, which has doubled its annual production capacity of uranium concentrate to 24 million pounds. It is the only facility in the world capable of processing high-grade uranium ore without diluting it. The mill processes the ore from the Cigar Lake mine, the world's second largest and highest-grade uranium mine. The McClean Lake site operates 365 days a year on a week-in/week-out rotation schedule for workers, over 50% of whom reside in northern Saskatchewan communities. Tailings are waste products resulting from milling uranium ore. This waste is made up of leach residue solids, waste solutions and chemical precipitates that are carefully engineered for long-term disposal. The TMF serves as the repository for all resulting tailings. This facility allows proper waste management, which minimizes potential adverse environmental effects. Mining projections indicate that the McClean Lake mill will produce tailings in excess of the existing capacity of the TMF. After evaluating a number of options, Areva has decided to pursue an expansion of this facility. Areva is developing the Surface Access Borehole Resource Extraction (SABRE) mining method, which uses a high-pressure water jet placed at the bottom of the drill hole to extract ore. Areva has conducted a series of tests with this method and is evaluating its potential for future mining operations. McClean Lake maintains its certification in ISO 14001 standards for environmental management and OHSAS 18001 standards for occupational health

Species of organic matter and their role in the formation of statiform uranium ores

International Nuclear Information System (INIS)

Goleva, P.K.; Uspenskij, V.A.

1983-01-01

Results of investigation of organic mather (OM) from stratiform uranium ore manifestation in sedimentary Upper Proterozoic rocks of large trough with caledonian folded base are given. Role of OM in concentration of uranium-ore formations of two ore-bearing horizons, presented by rocks of facies of large lakes (''lacustrine'') and continental deltas (''alluvial'') was clarified. Characteristics of OM of rocks of ''lacustrine'' and ''alliivial'' facies, OM types, chemical composition of OM of ''alluvial'' horizon rocks, om spectrograms and diffractograms are presented. It was established that OM of ''lacustrine'' and ''alluvial'' ore-bearing horizons are presented by different morphological and genetic types, which played different roles in t.he process of uranium ore-formation. Faneiy dispersed OM, related to the category of oxidized lower kerites is present in ''lacustrine'' horizon. Ore uranium-arsenide nuneral association substitutes OM of early generation. The latest OM generation is related to epigenetic thread veinlet of dolomite and barite. In ''alluvial'' horizon OM is present in the form of carbonized vegetative residues+ ciosely assocaating with sulfides of different metals, and is presented by high-moiecular carbocyctnc hydroxy compouds. Uranium of carbonized vegetative residues is in finely dispersed state; the form of its fixation was not established. It is proposed that the major part of uranium was sorbed by OM during sedimentogenesis

226Ra bioavailability of plants at urgeirica uranium mill tailings

International Nuclear Information System (INIS)

Madruga, M.J.; Brogueira, A.

2002-01-01

Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeirica mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides, some shrubs (Cytisus s.p.) are growing at some of the dams. The objective of this study is to determine the 226 Ra bioavailability from uranium mill tailings through the quantification of the total and available fraction of radium in the solid wastes and to estimate its transfer to the plants growing on the tailing piles. Plants and solid waste samples were randomly collected at dams. Activity concentration of 226 Ra in plants (aerial part and roots) and solid wastes were measured by gamma spectrometry. The exchangeable fraction of radium in solid wastes was quantified using one single step extraction with 1 mol dm -3 ammonium acetate (pH=7) or 1 mol dm -3 calcium chloride solutions. The results obtained for the 226 Ra uptake by plants show that 226 Ra concentration ratios for eucalyptus and pines decrease at low 226 Ra concentration in the solid wastes and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226 Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0±8.3 and 12.9±8.9, for the fraction of radium extracted from the solid wastes, using 1 mol dm -3 ammonium acetate or calcium chloride solutions respectively, were obtained. The 226 Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, within the standard error values, more consistent 226 Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. (author)

Composition and method for solution mining of uranium ores

International Nuclear Information System (INIS)

Lawes, B.C.; Watts, J.C.

1981-01-01

It has been found that, in the solution mining of uranium ores using ammonium carbonate solutions containing hydrogen peroxide or ozone as an oxidant, the tendency of the formation being treated to become less permeable during the leaching process can be overcome by including in the leaching solution a very small concentration of sodium silicate

Lead isotope results of acid leaching experiments on acid volcanics and black shales in an ore environment

International Nuclear Information System (INIS)

Gulson, B.L.

1977-01-01

In the volcanogenic Woodlawn Cu-Pb-Zn deposit, where pyrite is the dominant sulphide phase in the ore and a ubiquitous mineral in the host volcanics and shales, leaching experiments using HNO 3 -HCl to overcome the ore/rock lead dominance, resulted in highly complex lead isotopic data, dependent mainly on the original lead concentration in the rock. For samples with higher (> 5 ppm) lead concentrations, the acid leaches are less radiogenic than the rocks or residues whereas for samples with 15 ppm lead, the data arrays are those expected for a dominance of ore/rock lead. In all except the very high lead samples (> 100 ppm), lead is derived from sources other than sulphides. Furthermore, in only the highest lead sample is the acid leach isotopic value compatible with that of the ore lead. As found in previous leaching investigations, the dominant component of lead and uranium is extracted in the acid leach. Acid-leaching experiments of this type may have possible applications in prospecting for basemetal sulphides. (auth.)

Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach.

Science.gov (United States)

Mudd, Gavin M

2008-02-01

The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting.

Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach

International Nuclear Information System (INIS)

Mudd, Gavin M.

2008-01-01

The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting

Dose calculations for intakes of ore dust

International Nuclear Information System (INIS)

O'Brien, R.S.

1998-08-01

This report describes a methodology for calculating the committed effective dose for mixtures of radionuclides, such as those which occur in natural radioactive ores and dusts. The formulae are derived from first principles, with the use of reasonable assumptions concerning the nature and behaviour of the radionuclide mixtures. The calculations are complicated because these 'ores' contain a range of particle sizes, have different degrees of solubility in blood and other body fluids, and also have different biokinetic clearance characteristics from the organs and tissues in the body. The naturally occurring radionuclides also tend to occur in series, i.e. one is produced by the radioactive decay of another 'parent' radionuclide. The formulae derived here can be used, in conjunction with a model such as LUDEP, for calculating total dose resulting from inhalation and/or ingestion of a mixture of radionuclides, and also for deriving annual limits on intake and derived air concentrations for these mixtures

Radioactive wastes of uranium mining and milling: Radiological consequences for human population and natural environment

International Nuclear Information System (INIS)

Sazykina, T.G.; Kryshev, I.I.

2002-01-01

The sources of wastes and levels of radioactive contamination are considered in the areas of uranium ore mining and milling. Assessments of doses to the population are made using the methodology of multiple sources and pathways of exposure, including calculations of inhalation dose and doses from consumption of contaminated agricultural and natural products, as well as external exposure from the radioactive cloud and soil. On the local (0-100 km) spatial scale, the dose from uranium mining and processing is, on average, about 0.7 man Sv (GWa) -1 . The most significant pathway of the population exposure is inhalation of radon. The impact of uranium ore mining and processing on natural flora and fauna is determined by specific characteristics of the production at uranium mining enterprises and has both radiation and non-radiation components. The estimates of external and internal exposures to the natural biota in the vicinity of hydro-metallurgical works and tailing dumps are presented. (author)

A 197Au and 57Fe Moessbauer study of the roasting of refractory gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.

1989-01-01

The transformation of chemically bound gold into metallic gold during industrial scale roasting of an arsenical gold ore concentrate from the Fairview Mine, Eastern Transvaal, has been studied quantitatively by 197 Au Moessbauer spectroscopy. The iron compounds in the concentrate, mainly FeAsS and FeS 2 , and their transformations during roasting have been studied by 57 Fe Moessbauer spectroscopy. The bound gold is found to convert into the metal in parallel to the decomposition of FeAsS and the increase in cyanide leachability. This shows that the refractory character of the ore is caused by the chemical bonding of the gold rather than by the physical inclusion of small, discrete metallic particles in the matrix of FeAsS or FeS 2 . The ratio of the f-factors of gold bound in the FeAsS component of a refractory ore and of metallic gold was determined to be f(Au:FeAsS)/f(Au)=1.48 ± 0.09. (orig.)

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).

Radioecological investigations of uranium mill tailings systems: Final report for the period September 1, 1979 through April 30, 1987

International Nuclear Information System (INIS)

Whicker, F.W.; Ibrahim, S.A.

1987-01-01

This document is the final report on studies of the integrity and transport of uranium and radioactive progeny in active and reclaimed uranium mill tailings. The overall program was designed to provide basic information on the radioecology of 238 U, 230 Th, 226 Ra, 210 Pb and 210 Po, responses of plants and animals to the landscape disruptions associated with uranium production, and guidance for impact analysis, mitigation and regulation of the uranium industry. The studies reported were conducted at the Shirley Basin Uranium Mine, which is operated by the Pathfinder Mines Corporation. The mine/mill operation, located in southeastern Wyoming, is typical in terms of the ore body, mill process, and ecological setting of many uranium production centers in the western United States. The research was motivated originally by the general lack of knowledge on the transport of uranium and its radioactive daughter products through the environment, particularly through food chains in the immediate environs of uranium production operations. The work was also motivated by the relatively high contribution of uranium mining and milling to the radiation exposure of the general population from the nuclear fuel cycle

Determination of uranium content in phosphate ores using different measurement techniques

Directory of Open Access Journals (Sweden)

Mohammad A. Al-Eshaikh

2016-01-01

Full Text Available The most important unconventional source of uranium is found in phosphate deposits; unfortunately, nowadays its exploitation is limited by economic constraints. The uranium concentrations in phosphate ores in the world vary regionally and most countries with large phosphate deposits have either plant in operation to extract uranium or are at the stage of pilot extraction plants. The aim of this investigation is to evaluate uranium content in the Saudi phosphate ores for, at least, two reasons: firstly, upgrading the phosphate quality by removing the uranium content in order to reduce the radioactivity in the fertilizer products. Secondly, getting benefit from the extracted uranium for its domestic use as a fuel in nuclear power and desalination plants. The results of this study show that the uranium concentration in Saudi phosphate rocks is relatively low (less than 100 ppm, which is not economically encouraging for its direct extraction. However, its extraction as a byproduct from the phosphoric acid, which will have higher concentration could be quite promising and worth exploiting.

Effect of the milling conditions on the degree of amorphization of selenium by milling in a planetary ball mill

International Nuclear Information System (INIS)

Ksiazek, K; Wacke, S; Gorecki, T; Gorecki, Cz

2007-01-01

The effect of the milling parameters (rotation speed of the milling device and duration of milling) on the phase composition of the products of milling of fully crystalline selenium has been investigated. The milling was conducted using a planetary micromill and the phase composition of the milling products was determined by differential thermal analysis. It has been found that ball milling leads to the partial amorphization of the starting crystalline material. The content of amorphous phase in the milling products depends, in a rather complicated way, on the milling parameters. At the milling parameters adopted in the present study, the milling product was never fully amorphous. The complicated way the milling parameters affect the content of amorphous phase in the milling products is a result of competition of two processes: amorphization due to deformation and refinement of grains of milled material and crystallization of the already produced amorphous material at the cost of heat evolved in the milling vial during the milling process

PGAA method for control of the technologically important elements at processing of sulfide ores

International Nuclear Information System (INIS)

Kurbanov, B.I.; Aripov, G.A.; Allamuratova, G.; Umaraliev, M.

2006-01-01

Full text: Many precious elements (Au, Re, Pt, Pd, Ag, Cu, Ni, Co, Mo) in ores mainly exist in the form of sulfide minerals and the flotation method is often used for processing of such kind of ores. To enhance the efficiency of the process it is very important to carry out the operative control of the elements of interest at various stages of ore processing. In this work the results of studies for developing methods for control of technologically important elements at processing and enrichment sulfide ores, which content the gold, copper, nickel, molybdenum in the ore-processing plants of Uzbekistan. The design of transportable experimental PGAA device on the basis of low-power radionuclide neutron source ( 252 Cf) with neutrons of 2x10 7 neutr/sec allowing to determine element content of the above named ores and their processing products is offered. It is shown that the use of the thermal neutron capture gamma-ray spectrometry in real samples and technological products allows prompt determination of such elements as S, Cu, Ti and others, which are important for flotation of sulfide ores. Efficiency control of the flotation processing of sulfide ores is based on quick determination of the content of sulfur and some other important elements at different stages of the process. It was found that to determine elements the following gamma lines are the most suitable - 840.3 keV for sulfur, 609 keV and 7307 keV for copper and 1381.5 keV, 1498.3 keV and 1585.3 keV for titanium. Based on the measurements of original ores, concentrates of various stages of flotation and flotation slime the possibility for prompt determination of S, Cu and Ti content and thus to get necessary information on the efficiency of the flotation process was shown. (author)

X-Ray Fluorescence Spectrometry. I. Determination of thorium in ores

International Nuclear Information System (INIS)

Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

1961-01-01

A X-ray spectrometric method has been developed for analysis of thorium in ores in the range of concentration from 0.01 to 0.5 percent ThO 2 , using selenium as a internal standard. The concentration of thorium is determined in a working curve prepared by plotting the percentage of ThO 2 against the ratio intensity of the Th Lα 1 line to Sek β 1 line. (Author) 17 refs

On the possibility concentrating mill sewage treatment from coordination compounds of heavy non-ferrous metals with flotation reagents

International Nuclear Information System (INIS)

Monastyrskaya, V.I.; Borovkov, G.A.; Tsalieva, A.G.

1996-01-01

Complexing in the system metal ion (M = Cd, Co, Cu, Ni, Pb, Zn) - ligand (ethylenediamine, pyridine, xanthate, thiourea) and sorption of the complexes formed by materials on the basis of polyacrylonitrile (PAN) sorbents have been studied by the methods of spectrophotometry and voltammetry. It has been ascertained that PAN fiber base filtering materials are efficient sorbents for complexes of heavy nonferrous metals with flotation reagents and can be successfully employed for sewage purification at concentrating mills. 17 refs.; 6 figs.; 4 tabs

Application of isotope techniques to groundwater pollution research for Xiangshan uranium ore field, China

International Nuclear Information System (INIS)

Liu Fulin; Liu Peilun; Zhu Chuande; Wu Xiaowei; Zeng Yinsheng

1998-01-01

The investigation of groundwater pollution due to uranium deposits focused on the most important uranium metallogenic area-Zhoujiashan district of Xiangshan uranium ore field, China. Groundwater collected from five completed exploration boreholes in the area is regarded as the pollution source and is traced and analysed by using isotope as well as radio-hydrochemical techniques. In addition, the pollution situation of a small uranium ore pile for heap-leaching and a big uranium ore open pit are monitored by the same techniques. It has been experimentally proven that the uranium concentration and the uranium isotope ratio 234 U/ 238 U in natural waters are two sensitive indicators of radioactive pollution in natural waters. It was concluded that under present conditions, exploration of uranium deposits may not cause serious groundwater pollution of radioactive elements (U, Ra, Rn and Th), however, it is difficult to avoid the serious surface water pollution coming from the exploitation of uranium ore by a big open pit. (author)

Extraction of vanadium from campo Alegre de Lourdes (BA, Brazil) Fe-Ti-V ore by partial reduction/magnetic concentration/salt roasting/hot water leaching

International Nuclear Information System (INIS)

Alcantara, E.M.; Ogasawara, T.; Silva, F.T. da; Fontes, E.F.

1988-01-01

A process under development at COPPE/UFRJ to rocover vanadium from a titaniferous magnetite type ore from Campo Alegre de Lourdes (Bahia, Brazil), throxgh magnetizing roasting/magnetic concentration/ salt roasting/hot water leaching, is described. The results of the experimental work carried cut up to present are in qualitative agrement with those of othar studies on salt roasting/water leaching of titaniferous magnetites. Is is discussed the existing relationship between the maximum percentags of vanadium extraction in the leaching and the salt roasting conditions. (author) [pt

The treatment of uranium ores

International Nuclear Information System (INIS)

Michel, P.

1979-01-01

After having described the main steps in the treatment of uranium ores, the author describes the treament activities for these ores, as they are organized in France and in the African countries having made cooperation agreements with France in this field [fr

Determination of Au, Pt, Pd in gold ore mineral raw materials by stripping voltammetry

Directory of Open Access Journals (Sweden)

Kolpakova N.A.

2016-01-01

Full Text Available The paper considers the possibilities of use of the method of stripping voltammetry for finding platinum metals in mineral gold and ore raw material. A review of new options of electro-concentration of platinum metals on the surface of graphite electrode with the following sediment electro-oxidation and receipt of an analytical signal is presented: platinum finding was carried out by picks of selective electro-oxidation of iridium from intermetallic compound with platinum; gold finding was carried out by picks of gold electro-oxidation on the surface of graphite electrode modified by bismuth; palladium finding was performed by picks of palladium electro-oxidation on the surface of graphite electrode. 1M HCL solution was selected as a supporting electrolyte. Gold and hydrogen elimination on the process of palladium electro-oxidation was performed by means of UV irradiation of solution in the process of electro-concentration of palladium sediment. Gold, platinum and palladium determination was carried out in mineral gold and ore raw material of Verkhneamylskiy gold and ore district.

Bottle roll leach test for Temrezli uranium ore

International Nuclear Information System (INIS)

Çetin, K.; Bayrak, M.; Turan, A. İsbir; Üçgül, E.

2014-01-01

The bottle roll leach test is one of the dynamic leaching procedure which can meet in-situ mining needs for determining suitable working conditions and helps to simulate one of the important parameter; injection well design. In this test, the most important parameters are pulp density, acidic or basic concentration of leach solution, time and temperature. In recent years, bottle roll test is used not only for uranium but also gold, silver, copper and nickel metals where in situ leach (ISL) mining is going to be applied. For this purpose for gold and silver metal cyanide bottle roll tests and for uranium metal; acidic and basic bottle roll tests could be applied. The new leach test procedure which is held in General Directorate of Mineral Research and Exploration (MTA) of Turkey is mostly suitable for determining metal extraction conditions and recovery values in uranium containing ore bodies. The tests were conducted with samples taken from Temrezli Uranium Ore located in approximately 200 km east of Turkey’s capital, Ankara. Mining rights of Temrezli Ore is controlled 100% by Anatolia Energy Ltd. The resource estimate includes an indicated mineral resource of 10.827 Mlbs U_3O_8 [~4160 t U] at an average grade of 1426 ppm [~1210 ppm U] and an additional inferred resource of 6.587 Mlbs of U_3O_8 [~2530 t U] at an average grade of 904 ppm [~767 ppm U]. In accordance with the demand from Anatolia Energy bottle roll leach tests have been initiated in MTA laboratories to investigate the recovery values of low-grade uranium ore under in-situ leach conditions. Bottle roll leaching tests are performed on pulverized samples with representative lixiviant solution at ambient pressure and provide an initial evaluation of ore leachability with a rough estimate of recovery value. At the end of the tests by using 2 g/L NaHCO_3 and 0.2 g/L H_2O_2 more than 90% of uranium can pass into leach solution in 12 days. (author)

Nickel Ore Dispersion Evaluation and Consequences in Flotation Process

Science.gov (United States)