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By P. Klossek

It is estimated that China accounts for 94% of the world supply of rare earths (Roskill, 2011). This fact, together with the impact of China?s export policy, poses a substantial risk to the security of the rare earth supply as well as a rare earth price risk. This situation has motivated an increase in the number of rare earth projects under development, i.e., there are currently more than 440 worldwide (Technology Metals Research, 2012). However, economically and environmentally acceptable processing technology to produce tradable products from rare earths (e.g., separated rare earth oxides) is not freely available on the market at the moment. In this respect, a lot of research and development has been initiated on this topic, in academia as well as in industry. Using a proprietary model and scenario-based analysis, we studied the impact that the development of rare earth processing technologies would have on the rare earth market and the economic feasibility of rare earth projects mentioned before. The analysis showed that this impact varies depending on the technology type (e.g., technology can affect project production volume, cost structure or both) and the legal context of the invention (e.g., free or limited by patenting availability of a new technology). The effect of a technology which influences project production volume is not the same as of a technology which changes project cost structure. The impact of a patented processing technology differs from the impact of a processing technology which is freely available on the market. In the case of a new technology which is limited by patenting, its impact depends on the market position (?producing?, ?next-coming?, or ?not producing? project) of the patent holder. The paper contributes to existing research by studying the dependence of the expected micro- and macroeconomic impact of rare earth processing technology developments on the properties of a new technology (e.g., costs, legal framework etc.). By this means, the paper adds to existing knowledge and attempts to make the rare earths market more transparent and predictable from a perspective outside China.

Aug 1, 2013

By André Oliveira Galon, Elton Volkers do Espírito Santo, Caio Vaccari Silva, Victor Bridi Telles, Raphael Mariano de Souza

Para atender a demanda do mercado por aços com teores de fósforo cada vez menores, dominar os métodos desfosforantes mais eficientes é fundamental. Desse modo, o uso da termodinâmica computacional é extremamente importante, uma vez que as simulações vias softwares representam um caminho rápido, seguro e eficiente para se obter resultados no campo da aciaria. No presente trabalho foi proposto com uso do FactSage 7.2 a análise da eficiência de desfosforação de diferentes fluxantes: fluorita, sodalita, B2O3 e barrilha; que foram adicionados a uma mistura desfosforante padrão de 70g, nas simulações a massa total foi mantida constante em 70g e a porcentagem em peso usada dos fluxantes na mistura foi de 5 e 10%. Como tem-se em literatura que é possível correlacionar o fator de desfosforação (FDeP) com a eficiência, após o cálculo do FDeP feito através das simulações do FactSage, foi feita a correlação com a eficiência para se saber qual o fluxante era o mais eficiente e qual era o efeito do aumento da porcentagem em peso dos fluxantes na mistura desfosforante. A fluorita mostrou-se o fluxante mais eficiente seguido da barrilha, e a maior eficiência era atingida quando a porcentagem em peso dos fluxantes era de 5%.

Oct 1, 2019

By Henry S. Washington

I. INTRODUCTION. DURING the last twenty years or so the chemical investigation of rocks has made great advances, and it is now generally recognized that a knowledge of the chemical composition is as essential as that of the texture or mineral composition-if not more so-for the proper classification of rocks and study of their origin and relationships. Rock-analyses have vastly increased in numbers and, what is of greater importance, in quality. New and improved methods permit of greater accuracy than was possible in the early days, and the list of chemical constituents frequently determined has risen from the seven or eight of the greater part of the nineteenth century to twenty or more. Indeed, rock-analyses with determinations of so many constituents are now commonly made by the chemists of the United States and Australia, while in Germany, Great Britain, France, and Italy the rarer constituents are determined more frequently than formerly. As a consequence of this modern, accurate work, it has been discovered that some elements which were formerly supposed to be rare are of wide-spread occurrence and are often present in considerable amount. The fact is further being developed that the elements tend to show certain relations of occurrence or abundance in connection with each other. This is a fact which is applicable to the rarer elements, and which also finds a broad geological and petrological expression in the recognition of petrographic provinces. We are beginning to obtain some definite, though as yet rudimentary, knowledge of the distribution of the elements among igneous rocks. Some of the results along these lines obtained by study of the vast accumulation of analytical data now available are well known to petrologists, while others do not seem to be so gener-

Sep 1, 1908

By Jaisen Kohmuench, Michael J. Mankosa

Flotation has long served as the foundation for sulfide mineral recovery. As ore grades decline, however, this traditional approach is being pushed to the limit. Nowhere is this more evident than in the challenge of recovering coarse, partially liberated particles — an area where conventional flotation systems typically underperform due to excessive turbulence. As a result, valuable coarse minerals are often lost to tailings. Fine grinding has become the default solution, although with the added burden of higher operating costs and more challenging tailings disposal. To address the challenge of coarse particle recovery, Eriez developed the HydroFloat, a technology that uses a novel fluidized-bed approach to extend the upper particle size range of flotation significantly. The HydroFloat can recover particles exceeding 0.5 mm in diameter with a sulfide surface expression as little as 2 percent. Coarse particle recovery allows for optimization of comminution circuits for coarse gangue rejection before fine grinding. A substantial increase in overall tailings particle size provides higher water recovery due to improved drainage and allows for consideration of a dry, stacked tailings option instead of a tailings dam/impoundment. The technology’s transformative potential has not gone unnoticed. In recognition of its impact, Eriez was honored with the 2024 Robert E. Murray Innovation Award, commonly referred to as the Murray Award, by the Society for Mining, Metallurgy & Exploration. This prestigious award was established in 2017 to recognize organizations that advance the mining industry through the implementation of technical innovation. The HydroFloat stands as a fitting example of how creative thinking and industry collaboration can solve long-standing technical challenges.

Oct 1, 2025

By J A. Braithwaite

Social licence to operate is not a new concept for the mining industry, referring to stakeholder approval or acceptance for the activities and impacts of a project, company or industry. It is intangible, dynamic and non-permanent, hence it needs to be earned and then maintained (Thomson and Boutilier, 2014). It has also been argued that social licence extends beyond building approval or acceptance, into engagement for long-term development (Owen and Kemp, 2012).There are many examples where stakeholder opposition – or withdrawal of social licence – have increased capital and operating costs, extended schedules and impacted reputation. At its extreme, the withdrawal of social licence to operate can also contribute to or be the catalyst for mine closure.The key benefit of obtaining a social licence is a reduction of risk. Stakeholder support and advocacy, as well as the implementation of social performance programs that contribute to social licence, can be beneficial in terms of schedule, costs and other benefits.While decisions to close a mine are generally driven by resource availability or economic conditions, the social, economic and environmental legacy remaining post-closure is of importance to many stakeholders. With a number of significant mines now approaching closure within Australia, we are seeing heightened community concern about the economic and social impact of mine closure and the success of land rehabilitation. So how does the concept of social licence to operate extend into the closure phase of the mining life cycle?CITATION:Braithwaite, J A, 2016. Social licence to close?, in Proceedings Life-of-Mine 2016 Conference, pp 176–179 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By A. Nieto

Rare earth elements (REEs) are crucial to green technology such as hybrid-electric vehicles, wind turbines and fluorescent light bulbs. As of 2011, China dominates the global production of REEs and is reducing its export quotas. To predict the supply of rare earths in the United States based on future supply scenarios, a web-based database and geographic visualization tool was built. Five case scenarios with varying levels of REE demand were created by varying several economic conditions including (1) international trade policy, (2) greenhouse gas regulations, (3) environmental mining regulations and (4) tech applicability ratio of REEs. The most likely scenario, which is based on current international demand levels, indicates the importance of expediting the development of extractive operations of current REE resources within the United States. The results of the different case scenarios are supported by using dynamic geographic maps indicating the location of rare earth ore (REO) resources.

Jan 1, 2012

Domestic Production and Use: In 1976, 12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 63% of production capacity. Washington, Oregon, and Montana accounted for 36% of the total production; Gulf Coast States 19%, Northern States 29%, and other Southern States 16%. Based on published producer prices output of primary metal in 1976 was valued at $3.8 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1976 building accounted for about 25%; packaging 22%; transportation 19%; electrical 13%; , consumer durables 8%; and other uses, 13%.

Jan 1, 1977

By V. F. Parry, John P. Goodman

"INTRODUCTION Review of Previous Work Many investigators and certain commercial interests have recognized that the briquetting process is a practical method to convert much of what is now considered undesirable fuel into a usable form of domestic fuel.The art of improving the form of solid fuels is ancient, as early records indicate that the Chinese employed crude hand briquetting of combustible materials long before coal was known in Europe and America.According to Franke, 4/ the earliest description of a briquetting proce¬dure employed in the Occident is contained in an English patent dated in 1773. Following this in rapid sequence, many methods and procedures wore developed in this country and in Europe. Stillman/ states that the first attempt to briquet coal in the United States was made by Loiseau 6/ at Fort Richmond Piers, Philadelphia, in 1872. The American briquetting processes outlined by Stillman comprise an imposing compilation of successes and partial and outright failures."

Jun 1, 1943

By Heinrich Ries

I. INTRODUCTION. THE facts is presented in this paper, based chiefly on recon¬naissance made, during the summer of 1903, by myself and my assistant, Mr. R.. C. Brooks, cover practically all that portion of Texas lying east of the 99th meridian. The work was undertaken for the University of Texas Mineral Survey, and was to have been extended over the entire State, but the sudden termination of the survey prevented even the official publication of the results already obtained. Most of the mineral resources of Texas were fully treated by the First Geological Survey, but the clay-industry was tit that time little developed, so that only a few scattered notes concerning it are to be found in the Survey reports. The extensive exploitation of the clay-deposits, however, has emphasized their commercial importance, and has also made accessible many facts of exceptional interest concerning their geologic conditions. The erection of new plants for the utilization of clay-products is usually preceded by more or less prospecting, which, by reason of the scarcity of outcrops, and the geologic and topographic conditions of eastern and southeastern Texas, is often slow and difficult work. This is especially true in the Tertiary and Pleistocene areas, where the structural conditions much resemble those of the Atlantic coastal plain, the deposits being mostly lenticular in form, and surrounded by beds of sand. II. GENERAL GEOLOGY OF THE CLAY-DEPOSITS. The accompanying sketch-map, Fig. 1, shows the location of nearly all the deposits examined, their relation to the geology of the State, and the type of clay found in each. The geology is based on the published work of Hill, Cummins, Tail, Adams, Hayes and Kennedy, but the boundaries have unfortunately not been determined over the entire region covered by the map, and, in many areas, are only approximate. It will be seen that the clay-deposits range from Carboniferous to Pleistocene in age, the older deposits being found in the northwestern part of the area, while those of Cretaceous and Tertiary age lie to the east, southeast and south. The Pleistocene clays are found in part in a belt along the coast, and in part along many of the larger rivers, where they often underlie extensive terraces.

Sep 1, 1906

Federal Regulations require MESA to regulate the exposure of workers to inhalation hazards in the surface work areas of coal mining and processing operations. (1) The purposes of this study are listed below: 1. Determination of candidate inhalation contaminants for surface work areas of coal mining and processing operations. 2. Selection of appropriate sampling and analytical methods. 3. Performance of qualitative surveys of 56 representative coal mining and processing facilities. 4. Preparation of handbook to provide guidance for inspectors sampling for these contaminants. This report describes the work which was done to accumulate the information which was used in preparing the inspector's handbook. Specifically, this report contains descriptions of the surveys which were performed, analytical results obtained from these surveys, findings and conclusions, and recommendations for additional research.

Jan 1, 1975

By G. R. Speich, L. Zwell, H. A. Wriedt

HORNBOGEN1 has recently shown that it is possible to measure the degree of segregation accompanying cellular precipitation in ferritic Fe-Zn alloys by measuring the lattice parameter of the ferrite phase within the cell. In extending this work to study a wider range of composition and to evaluate the free-energy change accompanying the growth of the cells, the lattice parameter and the boundary of the a! phase in Fe-Zn alloys were redetermined to check the earlier work of Schramm.2 This appeared to be necessary since the Fe-Zn diagram has been drastically revised since the work of Schramm. Stadelmaier and Bridgers3 have recently shown that, contrary to prior belief: the y iron field is closed and the a phase boundary extends to an a + T + L peritectic at 782°C where peritectic a contains 42 at, pet Zn. The phase T in equilibrium with the a solid solution has a composition near Fe3Zn10 and a cubic 081 type structure.' The alloys were prepared by two different methods. In the first method carbonyl iron powder (400 mesh, 99.8 pet pure) and high-purity zinc powder (200 mesh, 99.99 pet pure) were mixed in a ball mill and then pressed in a die at 40,000 psi pressure to make compacts with a diameter of 5/8 in. and a thickness of l/4 in. These were sealed in evacuated quartz capsules, gradually heated to 1100°C over a period of 1 week (3 days at 600°C) 3 days at 800°C, 1 day at (1100°C), and then quenched in iced brine. For the alloys containing 23.4 and 30.1 at. pet Zn, the final homogenization anneals were performed at 1000" and 850°C) respectively, to prevent melting. In the second method, alloys were prepared by saturating high-purity iron millings (0.001 in. thick, 99.9 pet pure) in zinc vapor. For each alloy the impregnation was conducted at a fixed vapor pressure of zinc and a fixed temperature between 750' and 800°C. When saturated, the millings were quenched in water. The compositions of the alloys prepared by both methods are shown in Table I. The lattice parameters of the ferritic solid solutions were determined by comparing the 26 values of their 310, peaks (using Co Ka) or of their 211 , peaks (using Cr Ka) with those of corresponding peaks for high-purity a iron. The 20 values were measured at room temperature with an X-ray dif-fractometer (G.E.-XRD5). By using a fiducial value of 2.8664Å for the lattice parameter of pure a iron at 25oC,5 the lattice parameters of the zinc-bearing

Jan 1, 1964

By Secis R

Northparkes Mines is located 27 km northwest of Parkes in central west New South Wales. The E26 deposit is the largest of all defined to-date in the area, containing over 50 per cent of Northparkes' resources and reserves. The combination of orebody geometry and geotechnical characteristics provide ideal conditions for the block cave method of mining of the first lift of the E26 deposit. Although this method of underground mining has been used for decades in other countries, E26 is the first example of its use in Australia. Copper-gold mineralisation at Northparkes is related to quartz monzonite porphyries that have intruded coeval Ordovician volcanics. Sulphide mineralisation (dominantly bornite and chalcopyrite) occurs principally within quartz veins associated with the porphyry intrusions. Veining and mineralisation occurs within both the porphyries and volcanics. To optimise the recovery of a resource within a block cave mine, a good understanding of the rock mass and ore flow characteristics is essential. These have a significant effect on the fragmentation size and range and on parameters such as the drawzone spacing, height of interaction zone and dilution entry. As ore within a cave column moves and mixes when material is extracted from below and beside it, the total reserve extracted is unique for a particular draw strategy/production history. Until recently, reserve estimates and production schedules were based on the application of a uniform dilution factor to the tabulated resource. However, given the complicated flow and mixing within the cave column, such a simplistic approach can produce erroneous results. Northparkes Mines purchased and sponsored the upgrading of a commercially available software package specifically developed for modelling removal of resource blocks under caving conditions. This Gemcom software package, PC-BC, has been used for mine planning, reserve reporting and production scheduling. Blocks within it resource block model are converted into a mineable reserve taking into account mixing and dilution during depletion of drawcolumns (by horizontal and vertical redistribution of insitu tonnage and metal). As PC-BC gives individual drawpoint reserves, it can be used during the planning stage to determine whether or not a drawpoint is economic. For E26 Lift I an optimal layout containing 130 drawpoints has been developed based on a nominal 14 m x 14 m drawpoint spacing and a 0.8 per cent equivalent copper (eCu) cut-off grade. Annual production schedules for the depletion of material above this layout are based on: I higher tonnage removal from higher grade drawpoints in the early years of production; and 2 drawpoint production rates proportional to the total tonnage of orr remaining in the drawcolumn up to the optimal height of draw tier subsequent years. The reserve is tabulated from the combined annual production schedules over the life of the lift. The pre-mining reserve for Lift I of E26 is 26.6 Mt at 1.43 per cent copper and 0.39 g/t gold, of which approximately 23.4 Mt will be extracted under caving conditions. By scaling down the annual production schedule, weekly drawpoint tonnage calls can be given for short-tern production scheduling.

Jan 1, 1997

By Enrique Monge Gordillo

Si bien el fierro es el metal más barato en la industria minera, el incremento de su demanda y agotamiento gradual de sus depósitos, genera que su costo se eleve progresivamente. Por tal motivo, el objeto del presente texto describe el proceso de consumo del hierro y acero y su repercusión en el mercado occidental a través de cuatro capítulos: El primero, refiere a la demanda de hierro y acero tanto en Estados Unidos, los depósitos en Québec y Labrado en Canadá, el tratamiento y comercio de minerales de hierro; el segundo, a las operaciones mineras en Canadá y América Latina como las de Canadá, Venezuel, Brasil, Chile, Perú, México, Colombia, Cuba, Santo Domingo, Argentina, entre otros países; el tercero, revisa las plantas de hierro y acero en América Latina como las de Brasil, México, Chile, Argentina, Colombia y Perú, mientras que el último, refiere la industria de fierro y acero en los Estados Unidos, producción de fierro cochino y costos e importaciones del acero.

Jul 20, 1959

By L. E. Kun, R. O. Oelofsen, E. J. J. van Vuuren

High-rate floc-blanket clarification of gold pregnant rotary filtrate was introduced at the Vaal Reefs South gold plant of the Anglo American Corporation during February 1978. A. daily 12 000 to 15 000 t of filtrate, with an average suspended-solids concentration of 350 mg/I, is continuously clarified to a concentration of less than 2S mg/I of suspended solids in a modified plant pachuca (10 m in diameter) at throughput rates of 7,7 to 8,5 ma/m2.h by the addition of 5 g/t of ferric chloride inorganic coagulant and 0,2 g/t of Superfloc NI00 flocculant. The pachuca overflow is then clarified further in seven Stellar candle pressure filters of 54,S m2 surface area to under 5 mg/I of suspended solids. The combined clarification cost when the hopper clarifier is used in conjunction with the Stellar filters is R0,0032 per ton of liquid treated, which is approximately 60 per cent lower than the cost of Stellar filtration on its own. The savings are mainly due to the reduced use of filter pre-coat, the consumption of which has dropped by 70 per cent since the introduction of hopper clarification.

Jan 1, 1979

By R. Stauffer, S. Lindsay

"Sherritt Gordon Mines Limited utilizes pressure hydro-metallurgical techniques to recover nickel, copper and cobalt from su1phidic concentrates, mattes and various other metal-bearing materials.A brief description of the nickel refinery operation is given. In the nickel refinery process, an ammonia pressure leach is employed to treat the feed materials to dissolve the non-ferrous metals as their respective ammine complexes. The resulting leach solution goes through a series of steps which removes copper as copper sulphide and further purifies the solution prior to nickel precipitation by hydrogen reduction. The reduction end solution, containing the cobalt which was originally present in the leach solution as well as residual nickel, is treated with hydrogen sulphide. The resulting nickel-cobalt sulphide precipitate feeds the soluble cobaltic ammine process, which separates the nickel and cobalt and recovers the cobalt as a pure powder.A detailed description of the cobalt recovery process is given. Included are the various steps, comprising: acid leaching of the mixed sulphides, solution purification, ammine complex formation and cobaltous oxidation, two-stage nickel precipitation, cobalt conversion and reduction. A brief description of cobalt powder handling is included, along with typical physical properties and chemical analyses of the cobalt product. In general, the purpose of this paper is to describe the present plant practices employed in the recovery of cobalt as a by-product of the nickel refinery operations."

Jan 1, 1967

By E. G. Kearnery

Introduction It is believed that the present paper will be of some interest, not because of any outstanding features of Renabie milling practice but because Renabie is the first gold mining property in a newly explored area - in Leeson and Rennie townships, Sudbury district, Ontario - to reach the production stage. The Renabie mill was originally designed by the General Engineering Company (Canada), Limited, as a 300-ton plant and went into operation in June, 1947, treating an average of only 128 tons a day for the balance of that year. Toward the end of 1948 the capacity of the plant was expanded to 450 tons a day, and the tonnage treated was gradually increased from the 1947 figure to the point where 420 tons a day was averaged for the first nine months of 1949. Description of Ore In general, the outstanding gangue component of Renabie ore is white quartz, which comprises at least 80 per cent of its total bulk and in some sections considerably more. Virtually all the gold occurs in very finely divided state; only very rarely has free gold coarser than 325 mesh been observed. The ore has a very low sulphide content, ranging from about 0.50 to 1.00 per cent by weight. The gold occurs both free in the gangue and ? locked in sulphides, the proportion of one to the other varying considerably from one orebody to the other. Pyrite is by far the most abundant sulphide, followed by galena, which, however, appears to be entirely absent in some of the orebodies. Minor amounts of pyrrhotite, chalcopyrite, chalcocite, and sphalerite have been noted. The ore appears to be entirely free, or almost so, of minerals containing arsenic, antimony, or molybdenum, and in general it could be described as free milling. The various hindrances to extraction of the gold which have been met with are believed to be due largely to the very finely divided state of the metal and to its intimate association with the sulphides and gangue. The ore contains silver, with the gold-silver ratio about 3:1.

Jan 1, 1950

By Sam Kangwa, Thomson Sinkala

Th e re are three basic types of hole deviations in long hole d ri l l i n g , n a m e l y collar i n g , alignment and tr a j e c t o r y dev i a t i o n s . In mining, the accur a cy in drilling has a significant effect on the effi c a c y and economy of mining oper a t i o n s . This ar t i cl e d e s c ribes the types, s o u r ces and effects of hole deviations in mining oper a t i o n s . The art i cle further demonstrates the economic consequences due to hole dev i a t i o n s .

Jan 1, 2004

By H. Kenworthy

Sulfide-ore concentrates containing cobalt, nickel, copper, lead, and iron from the operations of the National Lead Co. at. Fredericktown, Mo., were treated successfully on a laboratory scale to recover more than 90 percent of the cobalt, nickel, and copper. A cobalt -nickel-bearing, lead-copper matte., produced by the St. Joseph Lead Co. at Herculaneum, Mo., was treated to produce a lead-zinc fume, a copper sulfide concentrate, and a cobalt nickel-iron product, netting a recovery of over 75 percent of the cobalt and about 90 percent of the nickel and copper. National Lead Co. bulk concentrates were chlorinated with gaseous chlorine to form anhydrous metal chlorides and sulfur chlorides, sulfur chlorides were recovered by distillation, a high percentage of the ferric chloride was converted to ferric oxide, and the chlorinated residual metals were extracted with water. Metal ions were removed from leach liquors by pH-controlled fractional precipitation as hydroxides. Cobalt solutions "were prepared from cobaltic hydroxide, and procedures were developed to remove contaminating metal ions. Purified cobalt solutions were employed as electrolytes for deposition of high-purity cobalt.

Jan 1, 1953

By W. J. Kotzé

Die derde colloquium van die Spesialiste-afdeling van die SAIMM is op 19 November 1980by die Universiteit van Pretoria gehou en is deur sowat 40 mense bygewoon. Dr J. P. Hugo tree as Voorsitter op en heet al die aanwesiges welkom, en stel elke spreker om die beurt aan die vergadering voor.

Jan 1, 1981

By J. R. Goode

There are at least a dozen methods of selectively removing cerium from a mixture of the rare earth elements (REE) including separation techniques based on the oxidation of cerium to the quadrivalent state. Several of the oxidation processes have been operated on a commercial scale, others have been tested and in some cases are part of proposed flowsheets. In this paper, we describe and compare the various methods. We also present preliminary estimates of the costs of early Ce removal and discuss recovery and purity aspects of the options.