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By N. V. Mel'nikov

This paper discusses the reserves of oil, natural gas and coal in the USSR, with particular attention to the future role to be played by coal in supplying the energy fuel resources of the country.

Jan 1, 1972

By S. Viswanathan, Q. Han, A. S. Sabau

"In spite of recent advances in the mathematical modeling of fluid dynamics for materials processing applications, no significant advances have been made in the numerical discretization of these equations. In this work, the application of two-step projection methods for the numerical simulation of interdendritic flows is discussed. Unlike previous methods, the methods presented here are constructed for the exact equations which are characterized by variable density and volumetric fraction of the liquid. The drag terms, which describe the momentum loss due to the flow around and through the dendrite structures, are treated implicitly. Numerical examples for shrinkage-induced flow during solidification of an Al-4.5% Cu alloy bar is used to illustrate the effectiveness of the proposed algorithm.IntroductionLiquid contraction during solidification plays an important role in the formation of casting defects such as shrinkage voids, microporosity, and macrosegregation. Owing to their importance, the study of transport processes during solidification have received considerable attention during the past years [1, 2]. By the use of volume-averaging techniques, the mass and momentum equations for flow through a stationary dendritic structure were derived [3]. By using the volume-averaging techniques for multi-phase systems, two-phase transport equations for solidification problems were derived [4]."

Jan 1, 1999

By Oliver C. Ralston

The Nonmetals Division studies problems relating to the use of minerals, many of which are important to national defense, for purposes other than the: extraction of metals. In fact, virtually all of the work of the division has been diverted to investigations pertaining to better use of the Nation's natural nonmetallics is resources as weapons of defense. The experiment stations of the division are at Norris, Tenn.; Tuscaloosa, Ala.; Seattle, Wash.; and College Park, Md. Studies involving the application of electric power to the nonmetallic minerals are conducted at the Electrotechnical Laboratory at Norris, and investigations on mineral-dressing treatment are conducted mainly at the Southern Experiment Station at Tuscaloosa. The cleaning and preparation of coal are studied at both Tuscaloosa and the Northwest Experiment Station Lit Seattle (other projects relating to utilization of coal are conducted by the Coal Division of they Bureau of Mines). Problems covering the use of minerals and fundamental problems as to their properties are studied at College Park.

Jan 1, 1941

By W J. Dyck

Past attempts to establish an integrated steel industry on the West Coast of Canada have been unsuccessful for at least three reasons: (a) insufficient reserves of a suit-able iron ore supply; (b) a relatively small local market for iron and steel; and (c) the non-availability of an economical process to produce primary iron on a small scale. Today, the reserves of economically mineable ore deposits are ample to support a steel production of 100,000 to 200,-000 tons per annum. The local market has increased so as to be able to absorb most of this capacity. With-in the next few years, a small integrated steel plant, including the "H-Iron" direct iron ore reduction process for electric furnace charge stock production, will be able to show a profitable operation. Introduction

Jan 1, 1963

By Glenn C. Reed

This report is one of a series describing investigations within the Missouri River Basin in Montana made by mining engineers of the Bureau of Mines Minerals Division, Region II. The primary purpose of these investigations is to provide information to agencies of the Department of the Interior and and others concerned with the planning of Federal power developments in the basin. The report contains such factual data as have been authorized for public distribution. The field investigations in Broadwater County were made during the late fall of 1948 and the summer of 1949. Virtually all known metallic mineral deposits and some nonmetallic mineral deposits within the county were investigated. However, some long inactive mines and prospects on which little or no information is of record may have been omitted inadvertently. Many of the mines and prospects have been inactive for extended periods. Most of the underground workings now are inaccessible. Because of such conditions, impressions gained by the inspection of surface features have been supplemented necessarily, where possible, by information obtained from Federal and State publications.

Jan 1, 1951

"Option pricing is used in finance for valuing options to buy (or sell) shares at some future date because it provides a convenient framework for quantifying values subject to uncertainty. As one of the main sources of uncertainty in mining is the price (sales) of the metal, this approach can also be used for valuing mining projects.The first part of this paper reviews options and option pricing; the second part presents the approach developed by Brennan and Schwartz (1985) for using option pricing to value natural resources. Several applications of this methodology have been published; these are described. From a mining point of view, the assumptions made by Brennan and Schwartz are too simplistic. The weaknesses are discussed with a view to improving an apparently promising new way of assessing the value of projects. IntroductionThe collapse of the British merchant banking group, Barings, has highlighted the risks that can be incurred by speculators and arbitragers in the futures and options markets. But this negative attention on futures and options should not make us forget their positive aspects. They can provide producers and consumers of metals with more predictable sales prices. The introduction of the new traded average price options, TAPOS, by the London Metal Exchange in January 1997 is a response to this need. Equally important, the theory that the finance industry has developed for valuing options provides an interesting framework for valuing mineral projects as well. While this paper was being revised, the South African gold mining house, JCI, announced that it was using a methodology based on option pricing for valuing the mineral rights to deeplevel gold resources (see Box 1)."

Jan 1, 1997

There is a saying, ?If it moves, it vibrates.? This is especially true in our modern industrial environments, where workers use powered tools, machinery, vehicles, and heavy equipment. How workers are affected by these elements of the industrial working environment is a concern of health professionals, govern­ments, and scientists around the world. How to adequately assess the effects of human vibration exposure is an equally important issue. The human body comprises a dynamic structure that is living, intelligent, and complex. Consequently, it is not unreasonable to consider that exposing the body to an array of vibration environments would result in outcomes that are not necessarily simple or easily predictable. Sensations caused by vibration may include nausea, annoyance, discomfort or pain, and exhilaration or pleasure. Many factors contribute to the effects of vibration on humans, including the characteristics of the motion and the exposed indi­vidual, the activities of the exposed individual, and various elements of the environment. There have been attempts to summarize the effects of occupational vibration exposures by simply recommending the avoidance of certain frequencies of vibration or by providing a graphical method, i.e., a single curve displaying all human responses to all frequencies. However, such efforts have not withstood the scrutiny of scientific research and analysis. Thus, attendees and participants at this professional gathering now have the rare opportunity to benefit from the technological advances and new scientific research to enhance their understanding of human responses to vibration that suggest more than a simplistic approach. In the tradition of the First American Conference on Human Vibration (1st ACHV) held in Morgantown, WV, June 2006, the 2nd ACHV provides a forum for scientists, engineers, medical doctors, industrial hygienists, and educators to learn and advance research and education in the specialized area of human body vibration. The conference was organized by the Mechanical and Industrial Engineering Department, University of Illinois at Chicago, with support from the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory. As with the first conference, the 2nd ACHV provides the unique opportunity to learn about the current activities of peers and colleagues and to exchange information on topics of interest such as human response, human modeling, experimental design, sensors, new technologies, and epidemiological studies of human responses to hand-transmitted and whole-body vibration. The conference organizers hope that the publication of these conference proceedings continues to foster new research and technological advances to reduce health hazards associated with occupational vibration exposures.

Jun 1, 2009

By G. D. Jermain

The Bureau of Mines investigated the Gypsum-Camel deposit on Iyoukeen Cove Chichagof Island, Southeastern Alaska, from April 21 to August 26, 1948, as A part of the United States Department of the Interior program for developing an Alaskan construction industry. As gypsum is one of the components necessary for the manufacture of cement and one of the raw materials for plaster and plaster-board products, it is desirable to locate and develop a readily accessible deposit of gypsum in Alaska. In 1928, B. D. Stewart of the Territorial Department of Mines surveyed the gypsum deposits at Iyoukeen Cove, and during the summer of 1946 George M. Flint, Jr., and Edward H. Cobb of the Federal Geological Survey examined and mapped the old workings at Gypsum Creek and the prospect at Iyoukeen Cove. Both the Territorial Department of Mines and the Federal Geological Survey recommended the Gypsum-Camel prospect as warranting a diamond-drilling program by the Bureau of Mines. The Bureau of Mines project consisted of cleaning out and sampling, the old underground workings and diamond drilling from the surface to ascertain the lateral extensions of the deposit.

Jan 1, 1952

By G. Herget

"A brief visit to European longwall mining operations in potash showed that retreating longwall mining provides a very attractive alternative to room-and pillar mining, especially in areas with bad roof, narrow seams and areas with high ground pressures. Mines de Potasse d'Alsace, France converted all potash operations to longwall mining in 1980. Recovery rates per panel vary between 75o/~ to 85% which compares very favourably with Saskatchewan values. Ground pressure in Saskatchewan are comparable to those of some of the deposits in Europe, but the presence of water in the hanging wall of Saskatchewan orebodies has to be given serious consideration. However, given the mining experience in Saskatchewan and the improved technology f or laboratory and field investigations, a review of present mining practice in Saskatchewan is desirable. IntroductionLongwall mining is practiced widely in coal mining and allows complete mechanization. It is applicable at great mining depth, in thin seams, weak roof and has been applied recently even to coal bed s dipping more than 65 degrees. Ideally this system allows complete extraction of an orebody. However, with high mechanization and emphasis on obtaining high outputs per man shift, extraction ratios rarely reach more than 80010 per panel.France, Spain and the U.S.S.R. have had longwall operations in potash for some time and a brief description is given below. Two of the operations were visited and the Russian operation is described based on German literature"

Jan 1, 1986

By R. Hurman Eric

Within the Ag-Pb-S ternary system, the boundaries of the immiscibility region together with the tie-line distributions were re-established at 925°C by the equilibrium-quenching technique where samples were kept in evacuated and sealed silica capsules. Activities of Pb were measured by the dew-point method along the Ag-Pb binary at 925°C, 1100° and l200°C, positive deviations were observed and the results were modeled by the Krupkowski formalism. Activities of Ag, Pb, and S, along the ternary miscibility gap were calculated at 925°C by utilizing the boundaries binary thermodynamics, phase equilibria and tie-lines. Activities of PbS within the pseudobinary Ag2S-PbS mattes were also measured by the dew-point technique and the results were again modeled by the Krupkowski formation where negative deviations were observed.

Jan 1, 2003

By G. Belardi

This paper presents the preliminary results of a research programme conducted to assess the feasibility of a flotation technique in the remediation of soils severely affected by heavy metal contamination. The use of flotation in soil remediation is a recent practice. The main difficulties are given by the variety and peculiarity of the heavy metal containing species, and also by the grain size. Most of the studies reported in the literature concern the use of conventional collectors, such as xanthates, after a preliminary chemical modification of the metal bearing species through sulphidization. On the basis of the minera-petrographic characterization and of speciation, some classes of reagents have been selected, capable of acting both on metal-bearing species and all metallic cations to be separated. The design of the synthetic molecules has been based on the coordinative properties of the metallic centres and functionalized in order to act as collectors for a wide range of metals independently on their surrounding atoms. In laboratory experiments a sample of stream sediment has been utilized, whose contamination is caused by the runoff from Sardinia mine waste dumps and overflow from the settling ponds. The material showed contamination mainly from Zn, Pb and Cu and to a lesser extent from Cr, Ni, Cd, and Sb associated in mixed particles of Fe and Mn. Flotation tests on a laboratory scale have been performed on grain sizes less than 355 µm in laboratory cell Minerais & Metaux. The effects of the structure of collectors (functional group, chain configuration) as well as of the principal flotation parameters (such as pH, concentration of reagent) on the grade and recovery of heavy metals in the concentrate and in the tailings (remediated soil) have been investigated. The results of the laboratory tests substantially confirm the theoretical premises, and the most effecive reagents found belong to the classes ATP, MBT, MBO, fat acids and phosphates.

Jan 1, 2014

By Anthony Sharkey

Introduction In Europe, longwall mining accounts for over 95% of coal produced from deep mines, whereas in the U.S.A., longwall accounts for less than 5% of deep mine coal production. There are many reasons for the difference, but in general: a. U.S. mine operators have invested heavily in continuous mining or conventional equipment which continues to produce acceptable results; b. There 1s a reluctance to change from, a familiar (and proven) mining method to an unfamiliar one, despite promises of huge production increases,; c. Multi-seam mining in Europe has made longwall the only really viable mining method, whereas In the U.S.A. multi-seam mining (particularly in "below-drainage" mines), is relatively rare; d. Although some spectacular results have been achieved by longwall in the U.S.A.(I), the general performance of longwall in this country has not been good enough to generate much enthusiasm for its wide application; e. The much higher level of investment in face equipment required for longwall when compared to alternative methods (approximately $7.5 million for a medium seam longwall installation and $1 million to $1.5 million for a continuous miner section). However, declining productivity, national energy requirements and safety legislation are creating a situation in which longwall as a viable mining method is being examined more closely and in more places than hitherto. This paper, therefore, attempts to identify some of the principal criteria needing examination in any assessment of the feasibility of longwall application, the limitations of information for those criteria in the decision making process and the need for further research and development to assist the mine operators make the decisions.

Jan 1, 1981

By J. L. Henry

The development and status of technology for producing titanium from U.S. resource materials are summarized in this Bureau of Mines report. Commercially feasible processes and investigations of alternative procedures are reviewed in order to identify techniques that could make existing operations more effective or areas in which future research may lead to the development of new production methods. Procedures are described for producing concentrated titanium dioxide from starting materials such as sands, massive deposits, and mineral processing residues containing rutile, ilmenite, and perovskite; producing and purifying titanium tetrachloride from concentrated rutile, ilmenite, and titaniferous slags; reduction of titanium tetrachloride to titanium sponge metal using metallic magnesium or sodium; purifying and consolidating titanium sponge and scrap by arc melting or induction melting techniques; purifying sponge, scrap, and alloys by molten salt electrorefining; and electrowinning titanium from chloride salts.

Jan 1, 1987

By Yunxing Cao, Xinsheng Zhang, Bingbing Meng, Shuaifang Guo, Li Wang, Junsheng Zhang

During the initial process of mining a longwall working face, it is often found that the roof will not collapse readily, which increases the risk of later roof collapse disasters. Explosive and hydraulic fracturing are common roof weakening techniques; however, they have certain limitations. In the present study, CO2 fracturing was used for roof weakening during the initial mining phase in the Changcun coal mine, China, which is a novel strategy. First, by analyzing the lithological characteristics of the working face and applying combined beam theory, the breaking spans of the top coal, immediate roof, and main roof were determined before weakening. An F-35 CO2 fracturing device with a rated pressure of 270 MPa was used, which provides fracturing energy equivalent to 0.968 kg of TNT. The fracture radius of the main roof was studied by ANSYS/ LS-DYNA combined with the hanging roof-breaking theory to determine the optimal layout of CO2 fracturing drills. The results show that the breaking spans of the top coal, immediate roof, and main roof were reduced by 3.99 m, 7.66 m, and 22.03 m, respectively. The main roof collapsed as the working face advanced, eliminating the chance of later roof collapse disasters. Compared with hydraulic fracturing and explosives, CO2 fracturing is safer and more practical, giving it significant application potential.

Nov 23, 2023

By Yotamu Stephen Rainford Hara

"The aim of our work is to investigate a low energy and clean route for the recovery of copper and cobalt from complex sulphide mineral concentrates. The mineral concentrates were roasted in air, in the presence of CaO (MS + CaO + 202 =MO+ CaS04) at temperatures below 973K. The roasted products containing CuO, CoO and Fe203 were carbothermically reduced at 1073K within an hour to preferentially reduce copper and cobalt. The kinetics of reactions were studied using the thermogravimetric technique and by characterisation ofreaction products using the XRDSEM-EDX techniques. The effects of MS:CaO ratio, roasting temperatures and physical nature of the mineral concentrates were analysed. The method for capturing S02 by forming CaS04 was analysed for reuse in the process. The energy balance for the above process is compared with that of conventional continuous smelting/converting process.1.0 IntroductionCopper sulphide mineral concentrates from Zambia contains substantial amouot of cobalt. The cobalt metal content in the concentrates ranges between 0.7 and 2 % weight, which corresponds to 3 and 9 % weight copper, based on the spot price of copper ($7 386/tone) and cobalt ($31 000/tone). Although the traditional approach using a combination of roasting-leaching-electrowining steps can be applied to recover copper and cobalt from sulphide mineral concentrates [1-4], there are two major draw backs of the traditional process: (i) the S02 emitted during roasting is too lean for economical conversion for sulphuric acid manufacture, which causes serious environmental pollution. (ii) silver and gold which are normally present in the sulphide concentrates are lost out [5] because they are not leachable by H2S04 or HCl which are the common leachants. The above two problems have been overcome by adopting flash smelting in which a rich S02 gas above 20% is produced [1, 5] and successfully converted into sulphuric acid. The precious metals tend to partition to blister copper and recovered during refming. However, nearly all cobalt is lost into the slag phase uoder oxidising condition which prevails during flash smelting. It is important to note that the cobalt content in the slag can be up to 2.6 % weight [6]. The recovery of cobalt from the slag is a process which requires huge amouot of energy since the slag is smelted above 1873K [6]. With a view of minimising the amouot of energy and S02 emission during metal recovery, our investigation involves roasting the sulphide concentrates in the presence of lime and reducing the roasted samples with carbon."

Jan 1, 2013

By M. Smutz, C. J. Baroch, E. H. Olson

IN 1949 an orebody containing some 10 billion lb of recoverable rare earth metals was discovered in the Mountain Pass district of San Bernardino County, California.' The following year Molybdenum Corp. of America purchased a number of claims at the deposit and a mill on the property which had been constructed to process the district's gold ores. Average composition of ore from the San Bernardino deposit is less than 0.1 pct Tho2, 25 to 35 pct calcite, 10 pct rare earth oxides, 15 to 20 pct silica, and 30 to 40 pct barite.' Rare earth content of the ore analyzes 50.7 pct CeO2, 4.2 pct Pr6O11, 11.7 pct Nd2O3;, 1.3 pct Sm2O3,, and 34.3 pct La2O3 and others.' By floating the barite and depressing the bastna-site, Molybdenum Corp. of America produced a concentrate that contained 60 to 70 pct rare earth oxides. More than 25 pct of the rare earths, however, was lost in flotation. It seemed likely that a more economical method could be found. At the present time most of the rare earths in the concentrates are converted to rare earth chlorides, which are either fed to ion exchange columns for separation of the individual rare earths or reduced to misch metal. Current investigation shows that solvent extraction may achieve this separation more economically than ion exchange. The study reported here was undertaken to develop an economical method of preparing a pure rare earth nitrate mixture from California bastnasite ore. Results indicated that more than 98 pct of the rare earths could be recovered. Several possibilities were considered for processing bastnasite ore, but only the method outlined in Fig. 1 was investigated. This involved leaching the calcined ore with nitric acid. The nitric acid process is discussed under the following headings: 1) calcination of the ore, 2) leaching of calcine, 3) filtration studies, 4) solvent extraction, and 5) nitric acid recovery. Calcination: Since California bastnasite ore contains 25 to 35 pct calcite and about 10 pct bastnasite, calcination was needed to reduce the violence of reaction with nitric acid. Weight losses of 26 to 30 pct were obtained by calcining the ore at 900°C for I hr or at 800°C for 4 hr. Longer periods resulted in no further weight loss. Leaching the Calcine: When the bastnasite calcine was leached with 30 pct nitric acid for 8 to 10 days, rare earth recoveries of only 45 to 50 pct were

Jan 1, 1960

By Steven A. Fechner

In 1991 and 1992, the Bureau of Mines completed chromium, platinum-group metals (PGM), and tin investigations, and started indium, manganese, titanium, and vanadium investigations in Alaska. These studies were done as part of the Site Specific Minerals Investigations project. As a result of this work, the Bureau found PGM-bearing composite plutons in the Yentna River area of the Alaska Range, which are chemically similar to composite plutons in other parts of the Alaska Range and to Ural-Alaskan type complexes. Previously unknown chromium and PGM occurrences were found in the western Brooks Range. A compilation report on the Bureau's chromium and PGM investigations in the western Brooks Range was also published. Indium was found in anomalous concentrations at the Lost River tin deposit. Small occurrences of manganese were located, mapped, and sampled in the Wiseman and Chandalar quadrangles, and in the Liberty Falls, Prince William Sound, and Homer areas. Tin occurrences in western Alaska were summarized in three Bureau open file reports. The beaches near Cape Yakataga and Yakutat were evaluated for their titanium potential and a sampling methodology was developed. Vanadium investigations included examining streams in the Wiseman and Eagle areas that contained anomalous vanadium values. In the Eagle area, high vanadium, uranium, and copper values were found in the basal layers of the Road River formation.

Jan 1, 1994

By Muhammad Hashim Rasa, Ali Aras

Recovering valuable metals from tailings not only provides a source of income but also helps conserve natural resources, thus reducing the environmental impact of mining activities. This study aimed to recover cobalt using tailings of the Küre flotation plant, which were determined to contain 0.17% Co. Flotation tests were conducted on samples taken from the tailings to investigate the effects of pH and pH conditioning time, as well as types and amounts of depressant, collector, and frother on the grade and recovery of Co in rougher flotation tests. Optimal flotation conditions were determined to be pH 6, a pH conditioning time of 7 min, and dosages of 50 g/t, 100 g/t, and 20 g/t of sodium hexametaphosphate, X-231, and DF250, respectively. According to the rougher flotation test results, a concentrate with a Co grade of 0.46% and a Co recovery of 84.15% was obtained. In the concentrate obtained using cleaner flotation tests, the Co grade increased to 0.49% and Co recovery increased to 90.56%. These results show that froth flotation, carried out with the appropriate reagents, is a successful method for recovering Co by enriching the flotation plant tailings.

May 17, 2023

By Carolina Person Maschio

Pelotas compostas de minério de ferro, aglomerante e coque foram analisadas quanto à resistência à compressão (a frio e após aqueciemento) e porosidade. Para isso, três lotes de pelotas foram confeccionados, com diferentes teores de redutor, até a quantidade necessária para reação completa com os óxidos de ferro. Após seu preparo, as pelotas passaram por diferentes tempos de cura ao ar. Ensaios de resistência à compressão à frio e porosidade foram realizados em pelotas verdes e com 3, 7, 14, 21 e 28 dias de cura. Após 28 dias, uma série de pelotas foram secas e submetidas a testes de resistência à compressão após serem aquecidas a temperaturas entre 200ºC a 900º. Analisou-se, também, a perda de massa em cada patamar de temperatura. Entre os principais resultados, verificou-se que o comportamento mecânico de pelotas autorredutoras é melhorado com o aumento do tempo de cura e prejudicado pelo aumento do teor de coque e aumento da temperatura. Após 600ºC, a resistência das pelotas cai potencialmente. Além disso, lotes com maiores teores de coque apresentaram maiores valores de porosidade, sendo que este aumento foi mais significativo nos primeiros dias de cura.

Oct 30, 2017

By Sang Joon Pak

Deep-sea mineral resources explored by Korea are categorized into mainly three types; manganese nodules, manganese crusts and seafloor massive sulfides. Manganese nodules have high Pt enrichment factors (EF=400, ore/crust ratios). Rare earth oxides (REO) contents from manganese nodules show from 0.037 to 0.302 REO% with mean value of 0.12%. Te and Pt are highly enriched in manganese crusts, displaying EFs of 10800 and 150, respectively. REO contents of manganese crusts are slightly richer than manganese nodules (0.013~0.387 REO%, average = 0.18 REO%). Seafloor massive sulfides deposits are featured by outstanding values of Se (EF=1300) well as In (EF=110). Au (0.8~26.3 g/t) and Ag (0.9~348.0 g/t) are another enrichment metals in SMS, although they belong to precious metals. Rare earth elements of SMS are meaningless as resources but REE are increasing in sediments overlying SMS. Heavy rare earth elements (HREE) from both manganese nodules and manganese crusts are typically higher than ones from land-based REE deposits. HREO grade and their portions of manganese nodules as well as manganese crusts are greatly similar to ion-absorbed type REE deposits in China, implying REE of subsea mineral resources are absorbed in nodules and crusts. Rare metals including REE could be exploited as by-production of commodities such like Ni, Co, Cu and so on. Rare metal resources from manganese nodules and manganese crusts are featured by low-grade and large scale deposits. Therefore rare metals in subsea mineral resources will add its economic values.

Jan 1, 2011