Showing papers on "Tailings published in 1980"

Separation of uranium by biosorption

Abstract: Uranium or thorium cations are removed from aqueous suspension or solution by treatment of the aqueous material with the biomass derived from fermentation of a fungal microorganism of the genus Rhizopus, e.g. Rhizopus arrhizus. The process can be utilized to treat aqueous tailings from uranium ore extraction processes, to reduce the radioactive content of the tailings prior to disposal.

Leachability of ra-226 from uranium mill tailings consolidated with naturally occurring materials and/or cement

Abstract: The leaching of Ra-226 from U mill tailings consolidated with cement and cement plus clay and/or peat may be described by a plane source diffusion model or a simultaneous first order reaction and diffusion model. A useful quantitative measure of the effectiveness of the consolidation process is the magnitude of the effective diffusion coefficient relative to that of the unconsolidated tailings material. The lowest effective diffusion coefficient upon consolidation was for consolidation with cement and peat.

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

Abstract: Introduction ------------------------------------------------------------Acknowledginents --------_ ----------------------------------------------Quantity and location of the tailings --------------------------------------Radioactivity in tailings --------------------------------------------------Sources of potential human radiation exposure from uranium mill tailings -----Radon emanation ----------------------------------------------------VVind transport ------------------------------------------------------Surface water transport and leaching ----------------------------------External gamma radiation -------------------------------------------Contamination of terrestrial and aquatic vegetation ---------------------Seepage ----------------------------------------------------~-------Environmental factors -------------------------------------------Ore factors -----------------------------------------------------Process factors --------------------------------------------------Use of tailings as a construction material ------------------------------Leaching behavior of radium, thorium, and uranium -------------------------Radium ------------------------------------------------------------Thorium Uranium -----------------------------------------------------------VVater qualuy studies ----------------------------------------------------Grants Mineral Belt in New Mexico -----------------------------------Elliot Lake, Ontario _______________________ --------------------------Other areas ---------------------------------------------------------Uranium mill tailings disposal options -------------------------------------Surface stabilization and near surface burial of tailings -----------------Radium removal from tailings ----------------------------------------Preconcentrationof uranium ore---------------------------------------Deep burial in underground cavities -----------------------------------Thick unsaturated zone storage· ---------------------------------------Fixation and agglomeration of buried tailings --------------------------In-situ leach mining -------------------------------------------------Conclusions -------------------------------------------------------------References ---------------------------------------------------------------

Nitrogen fixation (acetylene reduction) associated with rhizosheaths of Indian ricegrass used in stabilization of the Slick Rock, Colorado tailings pile.

Abstract: Indian ricegrass sown on a sandy soil covering a uranium mine tailings exhibited associative nitrogen fixation (acetylene reduction). Acetylene reduction rates for whole plants varied from 2,100 to 19,500 nm/4 days. Nitrogen fixation was associated with the rhizosheaths. It is suggested that the reclamation of mine tailings in arid climates may be facilitated by stabilizing sandy textured coverings with rhizosheath-forming grasses. Nitrogen fixation has been reported to be associated with rhizosheaths of Indian ricegrass, 0ryzopsi.s hymenoides, on sandy sites under conditions of moisture and nitrogen stress (Wullstein et al. 1978). During March, 1971, the Union Carbide Corporation (Beverly 1978) covered a uranium tailings pile, near Slick Rock, Colorado, with a loamy sand (Ludwick 1971). This covering was sown with a seed mixture including Indian ricegrass during October, 1973 (Beverly 1978). The seeding was relatively successful with respect to the Indian ricegrass only (Fig. 1). Examination of the roots in August, 1978, indicated general rhizosheath formation (Fig. 2). This report presents data indicating nitrogen fixation (acetylene reduction) is specifically associated with these rhizosheaths.

The use of algae to control heavy metals in the environment

Abstract: Aqueous effluents from a lead mining and milling operation located in southeastern Missouri, USA, caused a degradation of stream quality despite treatment by a large tailings pond. The receiving stream was choked with algal mats which accumulated unexpectedly large amounts of manganese, lead and zinc. A wastewater treatment system was designed to utilize algae and benthic macrophytes to remove metals from the tailings pond effluent. The system has proved successful and water quality in the receiving stream has been improved to drinking water standards.

Alberta Oil Sands Environmental Research Program

Abstract: The Alberta Oil Sands Environmental Research Program of the Governments of Canada and Alberta aims to establish baseline data on aquatic and terrestrial fauna, meteorology, and air and water quality. Air research topics include plume dispersion, chemical constitution and transformation within plumes, and the deposition of pollutants. Land system research covers subjects such as the effects of airborne emissions, soil chemistry, biochemical and physiological responses of vegetation and sulfur pathways, which are being studied with a sulfur isotope technique. Water system research topics involve mine tailings, saline waters from mine depressurization, natural river waters that flow through bitumen deposits, the effects of industrial waters on stream biota, and toxicological aspects of industrial contaiminants. The program, which began in 1975, has identified significant environmental effects owing to current oil sands developments.

Aluminum sulfate manufacture from aluminum dross tailings

Abstract: There is disclosed a method for the elimination of the chief impurities in aluminum dross tailings. The method can be used as a pretreatment in the manufacture of aluminum sulfate from aluminum dross tailings in a continuous flow reaction zone in which the dross tailings prior to reaction with sulfuric acid are pretreated to reduce the more objectionable contaminants contained therein to acceptable levels. The most objectionable contaminant in the dross tailings is aluminum metal which, in the invention, is oxidized with water or steam at elevated temperatures. The dross tailings, which are chiefly particles of aluminum oxide, are suspended in an aqueous slurry and the slurry is heated to a temperature from 185°-225° F. and maintained under liquification pressures and sufficient agitation to insure particle-to-particle attrition that removes an aluminum hydroxide coating which would otherwise inhibit the reaction.

Method of control of acid drainage from exposed pyritic materials

Abstract: Acid drainage from exposed pyritic material such as coal mine tailings is reduced through the controlled application of anionic detergents which inhibit the bacterium Thiobacillus ferrooxidans. The controlled application of anionic detergent comprises an initial application of anionic detergent in sufficient quantities to satisfy the adsorptive capacity of clay or clay-sized particles overlying the pyritic material coupled with the application of an anionic detergent inhibitor of Thiobacillus ferrooxidans from a slow release matrix containing the inhibitor. The two applications are to intercept infiltrating water up-gradient of the pyritic material or strata. The amount of matrix employed is calculated in accordance with a described formula. The method can be used to reduce acidity in drainage from pyritic mine tailings, coal mines, coal refuse piles and construction sites at which acid drainage is a problem. Acid drainage is also reduced by the mere controlled application of specific anionic detergents which inhibit the bacterium Thiobacillus ferrooxidans utilizing a detergent-containing matrix which provides detergent concentrations of greater than 10 ppm and preferably greater than 25 ppm in the infiltrating water.

Radium-226 in vegetation and substrates at inactive uranium mill sites

Abstract: Results of a study of the content of radium-226 in plants growing on inactive uranium mill tailings sites in the Four Corners Region of the southwestern United States and in plants grown under greenhouse conditions with minimal surficial contamination are reported. Field plant samples and associated substrates were analyzed from two carbonate tailings sites in the Grants Mineral Belt of New Mexico. Radium activities in air-cleaned samples ranged from 5 to 368 pCi/g (dry weight) depending on species and location: activities in plants growing on local soils averaged 1.0 pCi/g. The talings and local soils contain 140 to 1400 pCi/g and 2.1 pCi/g, respectively. An evaluation of cleaning methods on selected samples showed that from 17 to 79% of the radium activity measured in air-cleaned samples was due to surficial contamination, which varied with species and location. A survey of 18 inactive uranium mill sites in the Four Corners Region was performed. Radium activity in plant tissues from nine species ranged from 2 to 210 pCi/g on bare tailings and from 0.3 to 30 pCi/g on covered tailings The radium content in most of the soil overburdens on the covered tailings piles was 10 to 17 pCi/g. An experiment was more » performed to measure radium-226 uptake by two species grown on tailings covered with a shallow (5 cm) soil layer. A grass, Sporobolus airoides (alkali sacaton) and a shrub, Atriplex canescens (four-wing saltbush), were studied. The tailings were a mixture of sands and slimes from a carbonate pile. The tailings treatments were plants grown in a soil cover over tailings; the controls were plants grown only in soil. Three soil types, dune sand, clay loam, and loam, were used. The radium activity of the plant tissue from the tailings treatment compared to that of the appropriate control was 1 to 19 times greater for the grass and 4 to 27 times greater for the shrub. « less

Water Movements Traced by Metals Dissolved from Mine Tailings Deposited in a Fjord in North West Greenland

Abstract: The location of the studied area on the west coast of Greenland is seen in Fig. 1. A mining company has, since the fall of 1973, produced a zinc and lead concentrate, and 1400 tons per day of tailings with a chemical composition of approximately: 50% carbonate, marble and dolomite 50% FeS2, pyrite 1% Zn, mainly as ZnS, sphalerite 0.5% Pb, mainly as PbS, galena 0.01% Cd

Dewatering of industrial clay wastes

Abstract: As a part of research conducted to effect pollution a dewatering technique that allows for disposal of clay wastes, for reuse of water now lost with clays, and for reclamation of mined land was developed. The technique utilizes a high-molecular-weight nonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater materials containing clay wastes. In laboratory experiments, coal-clay waste, potash-clay brine slurry, phosphatic clay waste, uranium tailings, and talc tailings were successfully consolidated. Coal-clay waste was consolidated from 3.6 to 57%; potash-clay brine slurry was consolidated from 3.8 to 35%; phosphatic clay waste from 15.6 to 49%; uranium tailings from 15.4 to 67%; tailings from talc production from 9.7 to 53%; and an acidic TiO/sub 2/ slurr slurry from 1.68 to 30%.

Sepn. of non:ferrous metals from zinc ore tailings - by selective sulphation and leaching, leaving an iron rich material used as pigment or for iron prodn.

Abstract: Recovery of nonferrous metals from goethite-rich residues derived from wet processing of Zn ores is carried out by (a) treating the residue with a sulphating agent at 500-750 (pref.550-650) deg.C and (b) leaching the resulting sulphates from the residue. The sulphatinq agent can be H2SO4 or a SO3-contg. gas, e.g. produced by decompsn. of H2SO4 or a sulphate or derived from a contact process plant. The SO3-contg. gas can be enriched by injecting H2SO4. The treatment selectively removes Zn, Cu, In and Cd, leaving a Fe-rich material suitable for use as a pigment or an iron ore (FL).

Impact of mining activities on water quality in western North Carolina.

Abstract: An intensive water quality investigation was conducted in western North Carolina to determine whether water quality problems existed from point and nonpoint source inputs of sediment from surface mining activities. Depth integrated measurements of sediment transport and biological sampling of benthic communities indicated that very serious water quality problems were caused by erosion from a concentrated area of open pit mining for mica, kaolin, and feldspar. The erosion occurred on haul roads, active mines, inactive mines, and tailings disposal piles. The need for using specific “Best Management Practices” for erosion control on the mining operation is discussed. These practices need to be implemented to restore populations of trout to the degraded reaches of the river. Additional monitoring data are presented that indicate that the biological integrity of surface waters can be preserved in the vicinity of point source mining discharges when the operators utilize proper practices in settling and neutralizing their effluent. While much has been done to abate the point source discharges, attention now needs to be focused on the nonpoint sources of sediment from mining operations.

Interaction of Uranium Mill Tailings Leachate with Soils and Clay Liners

Abstract: This study evaluates leachate-soil interactions that will take place at the Morton Ranch for certain disposal alternatives. Laboratory tests were conducted to evaluate the following: 1) physical and chemical characteristics of geologic materials from the Morton Ranch. 2) physical and chemical characteristics of acid leach tailings and tallings solution, 3) leaching tests with selected tailings materials and leach solutions to evaluate the leachability of contaminants with time under specific disposal alternatives, 4) adsorption studies measuring the sorption characteristics of heavy metals and radionuclides on the geologic materials at Morton Ranch, 5) clay liner stability tests to evaluate effects of acid leachate on clay mineralogy and clay permeability.

A Preliminary Report from a Study on the Environmental Impact of Pyrite Mining and Dressing in a Mountain Stream in Norway

Abstract: The mining, milling and processing of complex zinc and copper pyrite ores causes water pollution in some districts of Norway To determine the effects of the wastewater from the mining and flotation process, and the acid mine drainage from an old, now exhausted pyrite mine, physical, chemical and biological investigations were performed in the Folia river during 1975–1976 The character of the stream is changed primarily by the inflow of sulphate, calcium and heavy metals In addition to higher concentrations of a number of substances, increased sediment deposition occurs, which is most distinct in the upper regions, downstream from the tailings impoundment The bottom fauna in the riffles, sampled by a Surber square foot sampler are qualitatively and quantitatively changed Ephemeroptera, which seem- to give the best picture of the pollution, are investigated at the species level In this part of the stream the mayfly fauna is represented by 5 families arid 14 species The impact of mine drainage on the bottom fauna, particularly on the mayflies is discussed in relation to the physico-chemical parameters

Shear strength, consolidation and drainage of colliery tailings lagoons

Abstract: Colliery tailings are laminated sediments which vary from coal-rich horizons of coarse sand size, to fine silt horizons composed mainly of quartz, illite and kaolinite. The proportion of finer laminae increases away from the inlet of the containing lagoon, although both fine and coarse bands are found everywhere in the lagoon. Coal itself has a low specific gravity and high friction coefficient. The density increases and the shear strength decreases away from the inlet. Both the average coal content (47%) and friction angle (35o) are higher for tailings than for coarse colliery discard (14% and 31o respectively). The permeability of the contrasting laminae differs greatly, and consolidation and drainage in lagoons is therefore dominated by the horizontally laminated structure. Much of the water in lagoons drains laterally to the embankments. This water contains dissolved solids which reflect the groundwater chemistry of the Coal Measures at depth, being both saline and rich in sulphates. Overtipping lagoons with coarse discard is being used increasingly for waste disposal purposes. It is possible to overtip with a 1.5m high layer of discard using a D6 vehicle at a sediment shear strength of 3 KN/m(_2) . However, to include a safety margin, 4.5 KN/m(_2) should be the lower bound. An effective stress stability study of overtipping indicates that a desiccated surface is necessary; the operation cannot progress where supernatant water remains on the lagoon. In terms of liquefaction hazards, vehicle vibration levels are not high enough to be of concern. Similarly, measured ground vibrations produced by explosives did not liquefy a lagoon being overtipped. It is suggested that a 200-year return period earthquake will not cause problems in this respect.

Biological Methods to Remove Selected Inorganic Pollutants from Uranium Mine Wastewater

Abstract: In many mining operations the mines are de-watered, i.e. water is pumped from the mines to prevent flooding of operations. The water often contains low concentrations of the elements being mined as well as other associated ions. These waters must be treated to meet governmental regulatory standards before being discharged. Some of the mine waters are used in milling processes, and become even more laden with soluble inorganic ions. These brines are pumped to tailings ponds for evaporation or eventual release to surface or ground water systems. Both mine waters and tailings solutions are valuable sources of metal and other ions, and it is both economically and environmentally sound to recover these elements. In the state of New Mexico, U.S.A., industries which must remove inorganic agents from large volumes of water are the uranium and molybdenum operations. Although precipitation, ion exchange, solvent extraction and electrowinning systems are available for soluble ion removal, these systems are quite often ion specific and very expensive when treating large volumes of water. An inexpensive and ion non-specific, accumulator system is the desirable alternative. The understanding and design of a functional bio-filter system for removal of uranium and other ions associated with uranium mining operations would alleviate discharge problems in the Grants, New Mexico, U.S.A. district (the producer of 46% of the U.S. uranium). Such a system would be applicable to other uranium-producing regions. The bio-filter process may also be applicable to other industries, with wastewater effluents containing trace elements. Among the extractive industries, the molybdenum operations have considerable need for economic and environmentally safe processes for purification of mill effluents.

Method and apparatus for beneficiating phosphate ores

Abstract: Method and apparatus for producing high grade phosphate rock from low grades, slime or tailings by subjecting the low grade rock, slime or tailings to a calcination treatment at a temperature within the range from 1000° F. to 1600° F., and preferably from 1400° F. to 1600° F., until a fraction of said rock, slime or tailings becomes magnetically attractable, and subjecting the treated material to a high strength magnetic field to separate the same magnetically into at least two fractions, one of increased BPL and one of decreased BPL.

Biochemical Beneficiation of Mining Industry Effluents

Abstract: One consequence of the industrial development experienced over the last fifty years has been the increasing demand for water for industrial purposes. This trend has also characterized the mining industry and, particularly, the mineral beneficiation plants. An average size Flotation plant treating 5 Tg of run-of-mine ore per day has a water requirement of at Least 20,000 m3. This not negligible amount of water must obviously be drawn from the natural hydrological resources of the area where the plant is located and, usually, for the host part, returns to it after the settling of the solids in appropriate tailings ponds.

Method for determining clay content in tailings and sludge

Abstract: A method for estimating the content of clay or clay minerals in the tailings or sludge resulting from the extraction of bitumen from tar sands and similar materials by titrating the tailings or sludge with methylene blue.

Fluidized Combustion of Coal Washery Wastes

Abstract: The operating performance of a 2.6 m x 1.6 m fluidized bed combustor with a nominal throughput of 2 tonne/h of wastes from a coal preparation plant is described. Results of plant trials are presented to show that combinations of coarse rejects and thickened tailings can be treated without recourse to auxiliary fuel. Calculations are presented which illustrate that with only small additions of coarse rejects the unthickened tailings could also be burned. The fluidized combustion of wastes from coal mining is shown to be not only a means of lessening the impact on the environment but also a source of considerable quantities of useful heat.

Effect of surface treatment of tailings on effluent quality.

Abstract: Successful reclamation treatment, in preparation for long range abandonment of mining wastes, involves both surface treatment and water quality control containment of waste solids and liquid contaminants. This paper describes use of lysimeters containing 125 tonnes of tailings to determine the impact of gravel, sawdust, and vegetation as surface treatments on the quality and quantity of effluent produced from sulphide-containing uranium mill tailings. Over a five-year period these treatments were observed and compared with bare tailings where no surface addition was made. The treatments did not alter the effluent quality to a level acceptable to regulatory requirements. Surface treatments did not appear to affect the leaching of Ra-226, NH/sub 4/ and NO/sub 3/. The concentration of Fe, SO/sub 4/, Cu, Pb, and Al increased with the rise of acidity as the pH changed from pH 9.5 to pH 2 in four and one-half years. However the rate and extent of changes of some of these parameters vary with the treatment. The experimental results for the observed trends are presented with limited explanation. Original design problems and unexpected delays in tailing reactions have made firm conclusions impossible at this stage. These data, however, provide a base for further investigation and developmentmore » of explanations and firm conclusions, as to the role of surface treatment in long-term waste abandonment.« less