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By A Turek

The Lake Cinch deposit occurs in the Tazin gneisses on the footwall side of the Black Bay fault. Ore is localized by two faults, the Main Ore fault and the Cracking-stone River fault, occurring in shoots along the former and on tension fractures between the two faults. Faulting leading to the localization of the deposit is analyzed in detail and tied into the regional pattern. Pitchblende, the chief radioactive mineral, is investigated by X-ray and found to be of very small particle size. The relation-ships of U, Fe and Mn in the ore are established quantitatively, and Fe is found to bear a catalytic relation to U. The deposit is classed as belonging to Lindgren's mesothermal class. Mineralization is attributed to carbonate solutions, and the uranium is believed to have been trans-ported in the hexavalent state as the uranyl tricarbonate ion; analogy is drawn to a recently developed hydro-metallurgical technique for the production of uranium dioxide. Introduction THE Lake Cinch deposit is located in the Beaver-lodge Camp, Saskatchewan. The property was staked in 1948 and went into production in 1957

Jan 1, 1965

By J Rubio

This work presents design features of an innovative in-line mixing helical (coiled) reactor for flocculation and flotation as a solid-liquid separation process for suspended particles (including liquid droplets). The device has been named flocs generator reactor (FGR), a compact system whereby the flocculation of particles is assisted by the kinetic energy transfer from the hydraulic flow through the reactor and/or by the injection of microbubbles (30 - 70 ¦m). The flow mixing presented a plug flow regime with a low dispersion degree, promoting the required hydrodynamic conditions to disperse the polymer flocculant (cationic polyacrylamide) and to generate æstrongÆ flocs of Fe(OH)3 or clays (as colloidal model systems) with aggregation using an anionic polymer, Al2(SO4)3 and poly aluminium chloride (PAC), and oil emulsions destabilisation with a high molecular weight cationic polymer. The solid-liquid separation of the flocs was then achieved either by settling or by flotation with microbubbles. This paper discusses advances in this new in-line flocculation-rapid flotation device to remove æaerated aggregatesÆ, aggregates with entrained and entrapped bubbles. Studies were carried out with different models of FGRs (varying the length:volume ratio) and process efficiency (mainly kinetics) evaluated as a function of polymer concentration and some operating parameters, namely, feed flow-rate, air:solids ratio and residence time. Results showed that the aerated flocs are readily floated with rising rates in the order of 120 mh-1, values higher than those obtained for the settling of the non-aerated flocs (18 - 24 mh-1). The FGR requires short residence times and generates dense, well structured flocs (with a mass fractal dimension, dF of about three) which withstand high shear forces. Mechanisms involved appear to include small bubble formation and their rapid occlusion (entrapment) within flocs, nucleation of bubbles at floc/water interfaces, polymer coiling as a result of æsalting outÆ effects at the aqueous/air interface and plug flow type of mixing (flocculation). Successful examples of emulsified oil and solids removal from water are shown and because in all cases high efficiencies were obtained (>90 per cent removal). Due to the high process efficiency and high loading capacity shown, the FGR appears to have good potential as an in-line flotation-separator device in applications requiring high rate solid-liquid or liquid-liquid separations.

Jan 1, 2005

Diamonds occur in N.S.W., Victoria and north west Tasmania. Diamonds from different areas appear to have their own characteristics, lending weight to the suggestion that three or four different sources (different in location and age) have produced the diamonds found in alluvials at quite a number of locations in Eastern Australia. Explorers for kimberlites in Victoria must overcome a number of field difficulties. The writer's approach attempted to find exploration targets by literature search, noting unusual garnet occurrences, and by relating records of diamond occurrences to described mining activity. While the records are biased towards gold, the study did lead to a pipe, located well away from known diamond-bearing alluvials. Core from one test hole has shown this intrusive to include an alkaline ultramafic breccia with many kimberlitic affinities - a breccia containing mantle-derived minerals, but not a true kimberlite. (A detailed rock description is appended to this paper, but is not the purpose of the paper.) This result enhances the possibility that kimberlites may occur in Victoria, on or near large scale faults or grabens. The depth of fracture penetration may have been different

Jan 1, 1979

By H. Rush Spedden, A. M. Gaudin

IN the belief that a critical study of its operating problems might be a sound investment, the Cuban American Manganese Corporation initiated an ore-treatment research in cooperation with the Massachusetts Institute of Technology. One of the early objectives of this research naturally became the relationship of the microscopy of the Cuban ores of the Corporation to their flotation treatment. The operations in Cuba have already been described by F. S. Norcross, Jr.7 and the laboratory study of manganese oxide flotation goes back a number of years .4 Broadly speaking, the difficulties encountered in the flotation of manganese ores are that the consumption of reagents is extremely high, the concentrate contains more silica than is desirable and the tailing losses are relatively high. An appreciable betterment on any of these scores would achieve a definite betterment in costs, quantity of minable ores, and quality of product. The microscope study discussed in this paper was made on samples from the Quinto mine, from the Ponupo mine, and from mill products at various stages of passage of the ore through the mill. The writers have had access to Company records and in particular to the petro¬graphic studies made on thin sections of ore by the late Professors R. J. Colony and Philip Krieger, of Columbia University. They acknowledge their debt to both of these men for the help derived from the reports. Manganese oxides are black, friable, smudging. It is, therefore, very difficult to judge operations by inspection. The mineralogy of manganese compounds seems to be confused, and the authors believe that many more minerals have been described than actually exist. Much of this difficulty is due to the prevalence of the structural conditions that will be discussed further in this paper; namely, the porosity and the friability of the ores, and the extremely intimate association of minute manganiferous mineral crystals with impurities of various sorts. By all odds the most important manganese mineral in Cuba is the one that in this paper is called "psilomelane." The name "psilomelane" has been used in so many different ways that the choice of it for this ore may not be approved by all. However, it seems to be the best under the circumstances. This mineral accounts for about 97 per cent of the manganese in the ores of the Quinto and Ponupo mines and in the mill feed. The remaining odd 3 per cent consists mostly of pyrolusite together with minor amounts of other manganese oxide minerals. DESCRIPTION OF PSILOMELANE Aggregate Structure In grains or lumps, psilomelane has a characteristic fibrous appearance and seems

Jan 1, 1942

By William A. Vogely

HIGH ACTIVITY, continuing the substantial recovery from the slump of 1954, characterized the domestic nonfuels-mining industries during 1956 Income generated in producing nonfuel minerals and mineral products3 increased 9 percent over 1955 as compared with a 6-percent increase for all industries. Thus, the 1956 performance of the mineral industries, while not as dramatic as the 27-percent increase obtained in 1955, continued to exceed the gains of the total economy. Other measures of mineral activity strengthen this conclusion. The index of physical volume of mineral production, presented for the first time as an integral part of this review, reflects significant gains in all major sectors during 1956; and, although the overall increase was diminished somewhat by the steel and iron-ore strike in July 1956, the all-mineral index (including fuels) reached a new high.

Jan 1, 1958

By R. S. Warfield

The Kasna Creek copper deposit near Lake Kontrashibuna in the Lake Clark region, Alaska, was the object of an investigative project by the Bureau of Mines during the fall of 1948. Recessed because of inclement weather, it was completed in 1949. This project was a part of the Bureau of Mines program in Alaska for the development of critical and strategic minerals. The ore bodies are contact-replacement deposits in limestone. Mineralization is mainly specular and micaceous hematite associated with chalcopyrite, calcite, chlorite, quartz, and amphibole. The deposit, on the right limit of Kasna Creek approximately 2 miles from the shore of Lake Kontrashibuna, is composed of two mineralized zones that range in altitude from 2,350 to 2,650 feet. This report contains a brief history of the prospect, description of the physical setting of the property, its geology, and the factual results of the Work performed by the Bureau of Mines.

Jan 1, 1951

By C. E. Wicks, F. E. Block, F. D. Stevenson

The vapor pressures of tungsten (VI ) chloride ( WC1 ) and hafnium ( IV ) iodide ( HFI ) were measured by a metal diaphragm technique . Vapor pressure values were obtained to permit calculation of the thermodynamic properties of the vaporization processes of the compounds . The vapor pressure data of WC16 are represented by the following equations for the liquid , B - solid , and a- solid over the temperature intervals indicated : - log P = 8.194 3,253 /T Liquid , 281.5 ° to 325 ° C : B - solid 230.0 ° to 281.5 ° C : log P a - solid 185.0 ° to 230.0 ° C : log Pam *** = 8.794 - 3,588 / T = 9.615 - 3,996 /T where T is the absolute temperature in degrees Kelvin . The heats of vaporization and sublimation are 14.9 , 16.4 , and 18.3 kcal / g mole , respectively . The entropy of vaporization at the normal boiling point , 330 ° C , was 24.3 eu . The fusion temperature , 281.5 ° C , and transition temperatures , 230.0 ° and 185 ° C , were found by thermal analysis .

Jan 1, 1964

By Milca Ventura dos Santos, Ricardo Rodrigues Grizotti, Luciano Henrique Andrade de Resende, Francisco Ricardo Casa Neto, Paulo Roberto de Oliveira Junior, Bruno Rodrigues Ferreira

O trabalho tem por objetivo demonstrar o processo de desenvolvimento e implantação da automatização nas operações, atividades de almoxarifados (recebimento, armazenagem, movimentação, inventário, picking e entrega de materiais), com o uso da tecnologia SAP FIORI com interface nos sistemas operacionais Android e IOS para utilização do Mobile (smartphones e tablet’s), já alinhado ao momento da indústria 4.0, visando inovações tecnológicas nos campos de automação, controle e tecnologia da informação. O desenvolvimento nesta nova plataforma visa tornar as operações de almoxarifados mais ágeis e eficientes, buscando otimizar o processamento das informações com mais rapidez, redução do tempo de permanência das mercadorias nas áreas de transferência e gerar maior rastreabilidade dos processamentos com interface direta e on-line com o ERP-SAP da organização. A metodologia do trabalho foi identificar as oportunidades de explorar as melhores potencialidades das soluções do SAP Fiori, alinhadas aos sistemas operacionais Android e IOS para uso de celulares, tablet’s, com comunicação através da rede interna e/ou 3G/4G sempre visando otimizar todas as atividades operacionais (fluxo de materiais) e administrativas (fluxo de informações) dentro dos processos dos almoxarifados e suas áreas de interface. O projeto iniciou-se e sendo implementado nas unidades de Planos (ArcelorMittal Tubarão e Vega), e com plano de expansão para as unidades de Longos da ArcelorMital Brasil durante o ano de 2019. Nesta primeira etapa o resultado alcançado foi de plena adequação, tendo sido encontrado benefícios em redução de erros; aumento de segurança; redução de custos; otimização de processos; transparência em dados; customização de produtos, o qual espera-se que a curva de aprendizado naturalmente nos levará a adoção de novas soluções incrementais resultando nos melhores níveis de gestão do processo de armazenagem e movimentação de materiais.

Oct 1, 2019

By F. J. Mehringer, C. W. MacGregor

VARIOUS investigations have been carried out to determine the effects of cold-rolling on the common physical properties as represented by the yield strength, tensile strength, percentage of elongation and ordinary reduction of area. Very little information is available in the literature with reference to the effects of cold-rolling on the true stress-strain properties. Since the ordinary physical properties base both the stresses and the strains on the original dimensions of the test piece, which are greatly changed during the test, they are essentially empirical values and do not represent physically either true stresses or true strains. Consequently, they do not give an accurate picture of the effects of different conditions, both mechanical and metallurgical, on the strength and ductility of the material. It is not, however, the purpose of this paper to review the various advantages accruing from the use of true stress and true strain values, since these have been shown elsewhere,1-12 but to utilize them in representing the various effects considered. The true stress S and true strain (e = q') values mentioned above for the tension test are defined by1 [ ] where P, A, Ao are the axial load, the instantaneous area and the original area of cross section, respectively. From simultaneous readings of the axial load and the dimension or dimensions determining the instantaneous area of cross section, the true stress-strain curve is constructed by using the relations given in Eq. I. It is then the object of this paper to discuss the general effects of cold-rolling on the true stress and strain values for a low-carbon steel together with the effects of age-hardening and directionality on these properties. PRELIMINARY INVESTIGATIONS The material considered throughout the paper is a low-carbon steel of the following chemical analysis: C, 019 per cent; S, 0. 118; P, 0.092; Mn, 0.85; Si, 0.01. The stock was received in bars, 7 by 3/4 in., and was first annealed for one hour at 1650°F. followed by a furnace cool. Photomicrographs of this material showed considerable directionality even in the annealed condition. In view of the possible effects of the nonhomogeneity and directionality in this material, it was considered important to investigate their influence on the true stress-strain diagrams. In addition, the effect of strain-aging in this steel was also made the subject of a preliminary study. Elect of Aging on True Stress-strain Properties Since a certain time element would elapse between the cold-rolling operation and the final tension tests, it was determined to investigate the aging character-

Jan 1, 1945

By Robert L. Stephens

"It can be argued that one of the most important property of any material is cost, since this property detennines the applications for which a material can be considered. Despite growing demand and production for commodity metals such as copper, nickel, zinc, lead, and tin, the cost of these metals has been steadily decreasing in real terms. The only way that metal miners and producers can remain financially viable in the long term is by continuing to lower their cost curve through the implementation of new metals production technologies. This paper reviews technological developments in the production of copper, nickel, zinc, lead, and tin that have or threaten to redefine the cost curves for these metals.DisclaimerThe opinions expressed in this paper the author's, and are not necessarily those held by the author's employer, Cominco Ltd.IntroductionThis meeting will discuss many novel technologies and processes for producing metals and materials with specific properties that will enhance the applications ranges for the material or will allow entirely new applications to be developed. However, in every real-world case, the cost of the new material or process is an important property that determines which applications the material or process can be used in. Other properties that are important depend on the applications.A recent press report (1) discussing the potential replacement of aluminum radiators with copper radiators in pickup trucks and sport utility vehicles provides an interesting example to reinforce the importance of cost in materials selection. In this case, the displacement of aluminum by copper is being considered because of the more favorable heat dissipation characteristics of copper. Heat dissipation has become more important due to the development of hotter-burning V-8 and V-6 engines. For this application, engineers also consider cost, weight, size, durability, and manufacturing process. The report stated that the development by the International Copper Association (ICA) of the ""CuproBraze"" manufacturing process for heat transfer products was an important development. This technology produces 845 radiators that weigh less, are more uniform in quality, and are potentially more compact. They are also expected to cost less in high production quantities than copper units produced in the past, last three to four times longer than soldered copper radiators, and the process also eliminates the use of lead solder from the manufacturing process."

Jan 1, 2000

By Juan Luis Bouso

El principal objetivo de este trabajo es conocer la distribución granulométrica de los productos grueso y fino que se obtendrían de un producto de alimentación en una separación o clasificación con hidrociclones. Asimismo, se busca determinar los principales parámetros que rigen la clasificación, como el tamaño de clasificación, generalmente conocido como d50, el reparto de masa en el clasificador y la carga circulante en caso de una clasificación en un circuito cerrado de molienda. Se recoge un procedimiento de cálculo que llamamos simulación, el mismo que se basa en el conocimiento matemático de la curva de la eficiencia de la separación en función del tamaño de corte deseado, o bien de alguno de los puntos de las distribuciones granulométricas de los productos a obtener en la clasificación.

Sep 20, 2019

By Margaret R. Egan

A study of the combustion emission products of rigid ventilation ducting was completed by the U.S. Bureau of Mines. The ducting was composed of fiberglass-reinforced polyester resin. Four properties of the ducting were evaluated: (1) propensity to ignite, (2) smoke characteristics, (3) gas emissions, and (4) heat release. Particle sizes, obscuration, optical densities, and production constants for gas and smoke were also calculated. These results provide comprehensive data about the emission products, detectability, and relative hazards of fiberglass-reinforced plastic ducting and other mine combustibles under realistic fire conditions.

Jan 1, 1990

By Leandro Augusto Viana Teixeira, Angela Avelar, Ruberlan Gomes Silva, Virginia S. T. Ciminelli, Daniel Majuste

Rare earth elements are essential for modern life products and green technologies. Recent supply constraints have boosted the development of rare earth projects after the price peak of 2011. The feasibility of a project depends on the definition of a processing route, which in turn depends primarily on the rare earth mineral, with monazite and bastnaesite representing the two most relevant minerals. Monazite-type ores usually contain high acid consumption impurities, such as iron, aluminum, calcium, magnesium, and phosphates, and may also contain prohibitive levels of radioactive thorium in its composition. This work presents a thermodynamic analysis of a monazite system and discusses the fundamentals of a selective process route for rare earth extraction from monazite ores with high iron content. This process involves sulfation by means of concentrated sulfuric acid and roasting at a high temperature. The route yields high rare earth extraction with low iron and thorium extractions and low acid consumption. Rare earth extractions as high as 80% were achieved, while iron and thorium extractions were lower than 1%, and acid consumption was lower than 0.34 kg of sulfuric acid per kg of ore. The operational window was compared to the one predicted by thermodynamic modeling, with 700 °C representing the optimal roasting temperature

This report summarizes the cost of U.S, mining and milling industry compliance with the Environmental Protection Agency (EPA) interim water quality guidelines for waste discharges. Applicable excerpts from Public Law 92-500 are stated and interpreted in conjunction with the guidelines being used for implementation of the law. Over 200 U.S. Army Corps of Engineers applications for discharge permits were used to develop the quality and quantity data base needed to estimate the cost to comply with EPA guidelines, Cost of three basic treatment methods were considered: Aeration, addition of lime, and sedimentation. From the process design, cost-capacity graphs were developed to consider maximum flow rate, maxi lime addition, and average flow rates. The graphical method used in this evaluation should provide a reasonable guide to the effect of waste treatment and, therefore, Public Law 92-500 and corresponding EPA guidelines on the mineral processing industry. The cost of complying with the EPA guidelines will have the effect of prompting the mining industry to minimize the production of waste water and of undertaking some additional treatment, Two case studies are presented to illustrate efforts that might be fruitful for minimizing waste water production and for treatment of combinations of acid mine drainage, mill wastes, and metallurgical process wastes when treatment is deemed necessary.

Jan 1, 1975

By D. B. Dreisinger, M. Rasouli

"Developing technology to address the environmental hazards associated with selenium in mine-impacted waters has been a serious challenge. Ion exchange (IX) has been identified as a potential treatment technology. This paper begins with a review on selenium adsorption with commercially-available basic anionic exchangers (BAS). It then looks at the use of resins for selenium removal via modification with the addition of -O, -N, or -S-containing chelating ligands and chelating polymeric ion exchangers pre-loaded with immobilized metal cations. The synthesis of chelating exchangers requires a final product with a highly stable metal in the ligand-metal complex. The nature, oxidation state, size, and affinity of the metal for the target oxyanions and the size, degree of protonation and space configuration of the oxyanion are among critical factors affecting the oxyanion uptake. There is a limited number of studies on the critical parameters affecting the selenium affinity for chelating exchangers. Such a study could fill in the gaps of our understanding of selenium-metal-chelating ligand interactions and assist in developing a new ion exchanger. In addition to commercial IX resins, layered double hydroxide materials (LDH) have received attention for oxyanion removal from waste water. The adsorption capacity of the LDHs are affected by the crystallinity of LDH, the nature of metal components, the ratio of metals, charge and type of anion, and the space between the layers. In particular, the Friedel phase (FP), a member of the LDH family, showed high adsorption capacity for selenate removal from synthetic solution. A study is currently underway at the University of British Columbia to investigate the effect of different synthesis methods and aging on the suitability of FP for selenium removal from mine waste water."

Jan 1, 2017

By A. E. Hilder

Introductory The following pages present the results of field investigations, laboratory and commercial tests, drilling, surveying, and preliminary development of the refractory clays which have been discovered recently in the township of Kipling, at the foot of Long rapids on the west side of the Mattagami river about 57 miles north of Kapuskasing and approximately 7 miles north of Smoky Falls, the terminus of the privately owned railway operated by the Spruce Falls Power and Paper Company, Kapuskasing (see Figure 1). Investigations on the clays of northern Ontario have been carried on over a period of seven years by officers of the Ontario Department of Mines, and I am indebted to the information published by that Department in reports by W. S. Dyer and A. R. Crozier, as well as?by Professor R. J. Montgomery, of the Ceramic Department, University of Toronto. It was, in large measure, the data given in the 37th, 38th, and 42nd Annual Reports of the Ontario Department of Mines that led me to make a personal investigation of the Mattagami River clays, with the result that we now have a commercial undertaking that will develop eventually into an industry of considerable importance in supplying the central manufacturing districts of Canada with refractories that heretofore have been largely imported from the United States. An extract from the 42nd Annual Report of the Department, Part III, 1933, page 75, reads as follows: "As for the refractory clay, the deposits are undoubtedly very large, but what is urgently needed is a deposit near the railway under sufficiently shallow overburden for recovery by stripping'. Having previously made an investigation of the clays adjacent to the Temiskaming and Northern Ontario railway, and these clays proving unsuitable, I turned my attention to the outcrops of refractory clays on the Mattagami river, first reported by Keele in 1919. This area offered possibilities within the economically permissible distance from rail transportation.

Jan 1, 1935

By P. M. Solozhenkin

On the territory Sakha (Yakutia) are located largest in Russian Federation reserves of antimony ores, Sarylakhsk and Sentochansk deposits, amaunt 10% of world stocks of antimony. A processing gold antimony ores Sarylakhsk deposit is carried out on gravitation-flotation circuit to receive gold gravitation concentrate and gold-antimony flotation concentrate with the contents of antimony over 60%. The gold-bearing concentrate is treated on place hydrometallurgicaly to a high-standard product, accepted by gold bank cash department. At the ore dressing plant reached the highest recovery in world in a concentrate of antimony 90%~91.6%, and gold 85.7%~86.0% as a result of scientific research works. Studied the mechanism of interaction cations of metals Pb2+, Cu2+, Cd2+, Hg2+, Ag+ with a surface antimonite presented on the basis of modern physical-chemical methods: nuclear quadrupol resonance, x-ray electron spectroscopy, electron spin resonance. The industrial tests of sodium dimethyldithiocarbate were carried out which confirmed high recovery of Sb and As. The leaching Sb2S3 by bacteria Desulfovibro desulfuricans and transformation antimonite in antimony trioxide by Tiobacillus Ferrooxidans improved following cyanidation . The extraction of antimony in a solution 96.0%~98.0% under optimal conditions. The common total extraction in the appropriate commodity products for gold reached 98%, for Sb 96.5%. At a combination of bioprocessing and cyanidation 85.5% of extraction Au was achieved. The new solvents for antimonite were found. Now by the Close Joint-Stock Co ?Sarylach-Antimony? industrial plant is constructed for processing Au-Sb concentrates to receive antimony trioxide and gold from various antimony deposits of Sakha (Yakutia).

Jan 1, 2014

By E. C. Tarpley, R. A. Drogowski, R. F. Abernethy

Three of the test methods frequently used for the determination of moisture in the analysis sample of coal were employed in analyzing a series of coals ranging in rank from anthracite to lignite . For most coals , the variation between the three methods are within the tolerances allowed between duplicate determinations by the same method . The processing variables studied included atmosphere , flow rate of atmosphere , inert atmospheres , oven temperatures , heating time , exposure of the dried coal to laboratory air , and surface area of the test sample . Unless close control is kept on these variables , erratic results will be obtained .

Jan 1, 1964

By Louis A. Turnbull

An investigation of coal deposits near Cerrillos Santa Fe County, N. Mex., was undertaken 14 the Bureau of Mines in 1943 as part of a general program to determine sources of metallurgical coal for western steel plants. Almost all of the coal used for metallurgical purposes west of the Continental Divide Is mined from the Lower Sunnyside bed in, Carbon County,, Utah. Coke used in western steel plants that is produced from Lower Sunnyside a coal is weaker, structurally, than coke used elsewhere in this country. For this reason, western coal operators and steel manufacturers are anxious to develop new areas of coking coal of better quality then the coal produced from the Sunnyside bed. The objective of investigations of western coals was to (a) develop additional reserves of coking coal to supplement proved reserves in the Sunnyside bed. and (b) develop; if possible, reserves of coal with coking quantities superior to those of Lower Sunnyside

Jan 1, 1951

By R. J. Kuczynski

The U.S. Bureau of Mines Reno Research Center investigated, developed, and patented a high-temperature cyanide leaching process for recovering platinum-group metals (PGM) from automobile catalysts. A batch pilot plant was constructed at the center and operated to demonstrate this technology to industry. Approximately 1,600 kg of used pellet, monolith, and metal support catalysts containing 1,700 g (54 tr oz) of PGM was processed. Forty-five-kilogram batches of used catalysts were leached with sodium cyanide solution at 160°C for 1 h in a countercurrent processing sequence. This selectively dissolved the PGM. Average extractions from the used pellet catalyst were 96 pet Pt, 95 pct Pd, and 73 pct Rh. Average extractions from the used monolith catalyst were 84 pct Pt, 81 pct Pd, and 66 pet Rh. Heating the pregnant leach solutions to 275°C for 4 h destroyed the PGM-cyanide complexes, causing over 99.7 pct of the PGM to precipitate from solution. The PGM precipitate was predominantly a metallic powder concentrate, typically analyzing greater than 50 pct PGM. Heating destroyed the cyanide to less than 0.2 mg/L free and total cyanide. Both the pellet and monolith residues were evaluated for disposal using the toxicity characteristic leaching procedure developed by the U.S. Environmental Protection Agency.

Jan 1, 2010