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By Eugene N. Cameron, Igor N. Sviatoslavsky, Harrison H. Schmitt, Gerald L. Kulcinski

The recent discovery of large amounts of helium-3, a valuable thermonuclear fuel, on the surface of the Moon has prompted engineers and scientists to examine the commercial attractiveness, thetechnological feasibility, and the environmental features of this important resource. The main feature of this fuel cycle is the low (˜ 1%) fraction of energy released in neutrons. Such low neutron fluxes result in important reductions in the amount of radioactivity, afterheat, and radiation damage in a fusion power plant. On the other hand, the high fraction of energy in charged particles and synchrotron radiation can be directly converted to electricity, resulting in very high efficiencies of electricity production (˜60.70%). It has been shown that there is 10 times more energy in He3 on the Moon than there ever was in fossil fuels (i.e., coal, oil, and gas) on the Earth. The techniques and equipment needed to extract the helium-3 have been examined and internationally acceptable mechanisms for the industrial development of this resource have been outlined. This paper expands on the financial, environmental, and technical aspects of the recovery of helium-3 for use in the 21st century.

Jan 1, 1990

By Charles A. Seitz

This Bureau of Mines report describes a chromatographic method for analyzing impurities in helium that utilizes a helium carrier gas contain-ing 25 to 30 ppm Ne. An example of the effect of trace amounts of nitrogen, methane, and moisture on the detector's response is shown. The added neon in the carrier does away with irregularities of the analysis which were experienced when the carrier contained up to 3 ppm Ne. The addition of 25 to 30 ppm Ne causes a loss of sensitivity, but the re-maining sensitivity is adequate for routine analyses. The high-neon carrier allows positive and more linear responses for eight impurities: neon, hydrogen, argon, oxygen, nitrogen, methane, carbon dioxide, and ethane. Neon concentration levels of 0.02 to 125 ppm in helium carrier gases were studied. The high-neon carrier has been in successful rou-tine use in Bureau of Mines helium facilities since October 1981.

Jan 1, 1985

By John Drew Ridge

Tables showing world trade in metallic mineral raw materials during the years 1953 through 1957 have been prepared for the following twenty-one commodities: alumina, aluminum, bauxite, chromite, copper concentrates, partly refined and fully refined copper metal, iron ore, pig iron, iron and steel (simple shapes), lead concentrates, lead metal, manganese ore, mercury metal, nickel ore, concentrates, and matte, nickel metal, raw pyrites, sintered pyrites, tin concentrates, tin metal, zinc concentrates, and zinc metal. In each instance, the amounts given by the importing country were used except when statistics from the importing nation were lacking, incomplete, or misleading. To show the considerable divergence between importing and exporting country totals for the same years, the complete mercury table is given and, in parallel columns, shows the comparable tonnages of importers and exporters. Tables for the other twenty commodities are presented in summary form. The data of the concentrate tables are used with those of the corresponding metals as a basis for a discussion of trade in concentrates versus trade in metals. The data of all twenty-one tables provide the basis for testing the thirteen rules governing international trade in metal raw materials which I first published in Mining Engineering for July 1955. Because the 1953 through 1957 data are far more complete and considerably more extensive than those on which the 1955 rules were based, it was found possible to deduce five additional rules and to modify three of the original thirteen appreciably. The full text of the eighteen rules is given.

Jan 1, 1960

By F. A. Rutledge

"The chromite deposits of Red Mountain, 10,miles southeast of Seldovia, Alaska, are in an intrusive of ultramafic rocks. The earliest reference to the deposits was made by U.S. Grant3/; J.B. Mertic, Jr. 4/ made a brief examination in 1917; and A.C. Gill5/ spent 7 weeks studying the ore bodies and geology of the region in 1918. The Federal Geological Survey had a field party in the region from July until September 1940 and the Red Mountain area was mapped and geological data were assembled by P.W. Guild.6/A preliminary investigation of the Kenai chromite deposits was made in July 1941 by R. S. Sanford,7/district engineer of the Bureau of Mines, accompanied by P. W. Guild, assistant geologist of the Geologi¬cal Survey. This was followed by surface sampling and core drilling, which were completed in September 1942 under the direction of John W. Cole,8 associate engineer of the Bureau of Mines. G. O. Gates, associate geologist, and A, B. Unkelsbay, junior geologist, of the Geological Survey, logged cores and interpreted geologic features revealed by Bureau of Mines drilling and trenching.9/J. C. Roehm, associate engineer of the Territorial Department of Mines; examined the Red Mountain area in august 1941.10/Additional exploration of other deposits in. the Red Mountain area was completed during the summer of 194. Work consisted of surface sampling, core drilling, and mapping. G. O. Gates, associate geologist of the Geological Survey, spent 4 days in August investigating results of the Bureau of Mines program.Throughout the exploratory work conducted by the Bureau of Mines the cooperation of Red Mountain Chromite, Inc., and especially of John Blodgett, Jr., and Collis 2, Druley, president and superintendent, respectively, was greatly appreciated. Use of their camp in the Windy River cirque and shops at Kasitsna Bay facilitated the Bureau of Mines program."

Apr 1, 1946

By E. R. Palowitch

This report is the result of a series of coal-cleaning tests using a dense-medium cone-type washer. Detailed results are given for 2 tests using a magnetite medium and 4 tests using a pulverized-refuse medium. Approximately 120 float-and-sink tests and over 500 separate chemical analyses were made in conjunction with these tests. In these tests higher recovery efficiencies and sharper separations were obtained when using a magnetite medium, especially on coal sizes below one-half inch. When sizes above 1 inch at low specific gravities of separation are cleaned, the pulverized refuse medium compared favorably with the magnetite medium.

Jan 1, 1956

Gold mineralisation was first noted in 1983 at the Wapolu Point area of Fergusson Island, Papua New Guinea (PNG) during a follow-up regional reconnaissance program. Subsequent exploration programs through to late 1987 completed 22,147m of costean trench sampling, 553 aircore/RC/diamond core drill holes (16,970.5m total) and metallurgical testwork, predominantly on the Wapolu grid in two mineralised areas.Subsequently in 1988, geostat-istical global and polygonal resources were calculated for the main mineral-ised zones, Didigayagaya and Dagwalala. In 1992, a 'probable total reserve' of 1.9Mf @ 2.4g/t with a 1.2g/t cut-off was calculated for these prospects.

Jan 1, 1994

By Qingwen Shi, Brijes Mishra

Laminated rock can delaminate and fail under certain stress states. Delamination-caused roof fall and cutter roof failure is a common failure mechanism in roadways in Pittsburgh coal seam due to the existence of laminated shale roof. Two-dimensional numerical models were developed at laboratory scale based on the bonded particle method in order to simulate the delamination with particle flow code. In these models, an assembly of bonded particles and parallel weak planes represents the laminated rock. This model calibrated the micro-parameters of the bonded particlematerial and weak planes with laboratory data. The mechanism of fracturing and delamination in a laminated specimen was investigated using unconfined and confined compression test and unsupported roof compression test. The numerical results show that, under a constant horizontal stress, delamination occurswhen the stress is much lower than its compressive strength. The confined compressive test indicates that delamination is restrained by applying confining stress since delamination-caused failure does not occur during any stage of the confined compressive test. Unsupported roof compression tests showed propagation of cutter roof failure with initiation of cracks and delamination at the intersections of the roof and ribs. An outer failed zone and inner failed zone form separately. The separated zones connect and form an opening in the roof. The presented numerical results provide additional insight into process of delamination.

Sep 14, 2020

By Krahmann, Rudolf

THE following is an account of a survey undertaken to test the possibility of outlining a kimberlite pipe by magnetouietric methods. Kimberlite is a basic igneous rock closely related to melilite-basalt or alnoite, which occurs either in the form of volcanic plugs or as dikes intruded into rocks of various types and geological ages up to and includ¬ing the Lower Cretaceous. The famous diamond mines of South Africa are all in kimberlite pipes and these pipes are probably the original source as well of the vast alluvial deposits found in various parts of the country. The pipe chosen for this experiment is one that ' occurs on the farm Goedgevonden No. 20, about sixteen miles north of the village of Klerksdorp and ninety miles southwest of Johannesburg. Some prospecting has been done on this pipe and diamonds were produced from it but not in paying quantities. The magnetometric survey was made in June, 1932, by R. Krahmann and H. Wallisch and the results are shown on the accompanying plan. On the plan are shown also the boundaries of the pipe as exposed at the surface and details in regard to the surrounding foundations. These are taken from a geological survey made at a later date by W. Beetz, of Johannesburg.

Jan 1, 1935

By Afrânio Márcio Costa

Placas lingotadas continuamente, não obstante atendam a requisitos como composição química, conteúdo de inclusões, aspectos macro e micrográficos, podem ser desclassificadas por falta de conformidade dimensional. Contrações térmicas, de solidificação e de transformações de fases são partes intrínsecas do processo e são afetadas por alterações na taxa de extração de energia da placa durante o processo. Este conjunto de contrações determina o Fator de Contração de operação, o qual é utilizado para determinar as dimensões do molde que irão resultar na largura especificada, onde o presente estudo determinará o fator de contração dos aços peritéticos. As variáveis identificadas que influenciam no fluxo de calor primário foram: frequência de oscilação, superaquecimento, velocidade de lingotamento e viscosidade do pó fluxante. Identificou-se que o resfriamento secundário e a conicidade utilizado no molde, também são critérios determinantes para obtenção de larguras especificadas. Assim sendo, uma equação de regressão foi desenvolvida para o Fator de Contração.

Aug 17, 2017

By David A. Summers

Coal is increasingly viewed as one of the major fuel resources of this country for the remainder of this century. The need to extract a greater percentage of the coal in a given seam, together with advantages of improved safety, indicates that longwall mining will become more widely used within this time frame. A novel method of mining coal on a longwall face, utilizing high pressure water jets, is herein described. The mining machine proposed will exploit the stress conditions which exist on a longwall panel in order to achieve the required productivity while at the same time reducing respirable dust and methane ignition hazards. The water jets will excavate only the boundary of the extracted seam section, and thus the energy requirement of the machine will be minimized. The action of the machine is similar to that of an existing coal plow, except in that the wedge teeth of the plow are replaced by oscillating high pressure water jets. The machine can, therefore, cut to the depth and at the speed of existing shearer units at equivalent power levels. The removal of impact stresses from the machine will reduce downtime required for maintenance and replacement of picks and lower the load on the haulage motor of the system. The ability of the machine to increase the depth of cut without an increase in horsepower will further improve productivity when transportation systems to remove the greater production are in operation.

Jan 1, 1974

By Arif Emre Dursun

The aim of this study is to present hazard classifications of location, type, and causes of accidents in Turkish coal-extracting industries using Analytic Hierarchy Process (AHP). In this study, fatal mine accidents were analyzed by pairwise comparison and weighting, and the most important hazards were identified by determining the effective main and sub-criteria among location, type, and causes of accidents. For this purpose, 1st, 2nd, and 3rd level hazards consisting of location, type, and causes of accident were determined by using the data of fatal mine accidents in underground and open-pit coal mining in Turkey between the years of 2010 and 2020. And then the data were categorized, and each category was prioritized using the AHP technique. According to the weights calculated by AHP, the most dangerous main criteria at 1st level hazards in underground coal mining is ventilation operations (0.363), while the most dangerous sub-criterion at 2nd level hazards is firedamp explosions and other gas accidents (0.409). On the other hand, in open-pit coal mining, the most dangerous main criteria at 1st level hazards are slopes and benches (0.575), while the most dangerous sub-criterion at 2nd level hazards are landslides (0.429).

Dec 30, 2023

By Courtney A. Young

Cyanide is a critically important chemical to the mining and metallurgical industry. It has a strong affinity for metals making it favorable as an agent for metal finishing and treatment as well as a lixiviant for metal leaching, particularly gold. These technologies are environmentally sound but, because cyanide is very toxic, safeguards are required to prevent accidental spills and treat effluents before being discharged. Various methods of cyanide remediation by separation and destruction for cyanide management purposes are therefore reviewed. The methods have been broadly categorized as physical, -adsorption. complexation and oxidation methods including photolysis and other advanced-oxidation processes. Reaction mechanisms for these methods are presented throughout this paper, Finally, the methods are compared in regards to their effectiveness in treating various cyanide species: free cyanide, thiocyanate, weak-acid dissociables, and strong-acid dissociables.

Jan 1, 1998

By G. J. Perrott, H. W. Clark

During the course of the cooperative smoke abatement investigation carried on by the Bureau of Mines , the city of Salt Lake and the University of Utah during 1919-1920 , a study was made as to the suitability of Utah coals for by-product coking with particular reference to low temperature coking . was done because it was realized that a smokeless fuel for domestic consumers was the best remedy for this class of smoke producer . A report of the technical side of the work was included in the final report of the cooperative investiga- Since this report was written (June 1 , 1920) further work has been done by other investigators .

Apr 1, 1922

By Groom P.

The wastage of timber in coal-mines that is caused by decay is very great; in fact, far greater in this country than is generally realized. Mr. E. W. Peters estimates that of the whole wastage of timber in mines in the United States of America, 50 per cent, is due to decay and insects; of this 50 per cent, an overwhelming part is due to decay. The most efficient methods of decreasing this grave loss can be devised only by co-operation of the mining engineer and the scientific expert, and it is partly in the hope of procuring such collaboration that this paper is written. It contains, therefore, a resume of our present knowledge of the decay of wood, and of the economic methods of checking this in mines; but, with a view to improving those methods, it also directs attention to the gaps in our knowledge and the means by which these can be filled by future investigation

Dec 1, 1916

By Egil Aukrust

"An American Iron and Steel Institute Task Force evaluated developing direct steelmaking technology worldwide to seek a replacement for the coke-oven, blast-furnace, basic-oxygen process technology now in use. To remain internationally competitive it is essential to move away from the traditional series of batch processes towards continuous processing and the associated energy savings which are possible with high technology process control systems. The group identified in-bath smelting of iron ore pellets or fines with coal as the process most sui table for domestic raw materials (including abundant scrap) and called for research to study operation with varying degrees of preheat and prereduction of the ore by the gases generated from the coal and various degrees of combustion of these gases above the melt.A coordinated, 3-year, $27 million, direct steelmaking research program is proposed. Concurrent projects include design, construction, and experimental operation of an in-bath smelting pilot plant; modeling, simulations, and laboratory-scale experiments at universities on slag-phase and metallicphase reactions and interactions; and large-scale heat transfer and reaction rate trials. Also included are modeling studies and pilot plant trials of on-stream decarbonization and desulfurization; application of circulating fluid bed technology to fine ore reduction and hot gas cleanup; and specific heat transfer and fluid flow research projects.IntroductionThe American Iron and Steel Institute (AISI), based on the Task Force studying direct steelmaking, believes strongly that a coordinated program of research on the reduction of domestic raw materials to liquid steel should be undertaken as part of the Steel Initiative program. To specify the steelmaking process for development best suited to the American steel industry and domestic raw materials, it was important to determine the state-of-the-art of direct steelmaking worldwide, both as practiced and under development, and then, by expert analysis of the processes and their potentials, to choose the process most likely to provide a domestic competitive edge."

Jan 1, 1988

By Verya Nasri, Jaeseoung Lee, Ashish Bhargava, Shashank Gupta

This paper presents the unique design and construction challenges for the Technoparc Station, located in downtown Montreal as a part of Réseau Express Métropolitain (REM), a light rail rapid transit system. The station is located 15 m below the street with rock-bearing secant pile wall as the primary structural system working as both the retaining and gravity structure. The paper highlights the challenges related to the support of excavation structure, invert slab resisting high hydrostatic forces, waterproofing tightness etc. It also focuses on the importance of Building Information Modeling (BIM) in underground tunneling projects for effective coordination, clash-free, optimized design and costs.

Jun 13, 2021

By P. K. Jain

A spiral concentrator is a density separation device used for the beneficiation of coal and various minerals such as iron ore, chromite ore, gold, beach sand minerals etc. The flow pattern developed in the equipment is complex and unique, yet the operation is very simple, with low capital and operating expenditure. Spirals are applied for beneficiation of material in the size range finer than 2 mm and are capable of recovering heavy minerals as fine as .01 mm. The understanding of the unique flow pattern has kept researchers engaged over the last few decades and attempts are being made to explain such flow patterns so that they can be controlled and modified to improve the operating efficiency, Ep (Ecart Probable Error, also known as probable error in separation) and acceptability of spiral concentrators for processing of fines and slimes - currently being discarded and dumped in the tailing ponds. An attempt has been made in this paper to explain the generation of complex flow patterns with application to classical solid mechanics in the fluid and slurry system. The same has been used to explain the selective separation of particles in different zones in a cross-section on the spiral trough. The paper also discusses the application of a force balance model to explain the generation of secondary circulation. Due to the presence of laminar and turbulent flow regimes in the spiral concentrator, varieties of equations have been proposed in the literature, consisting of different equations for different zones. An attempt has been made to present a unified flow equation for calculation of flow velocity at different positions on the spiral trough. Keywords: Secondary circulation, spiral concentrator, density separation, fine particle processing

Jan 1, 2020

By Nadia H. Rafat, Iman S. El-Mahallawi, Hussein Badr, N. Khattab, Ahmed A. Abdel-Rehim

The basic part of solar water heaters is the collector and the main functional part of the collector is the absorber layer. In this work, a commercial locally available black painting (PACEN code 10382 colour 890), used for swimming pools solar heating, was modified by adding nano-graphite dispersion. The effect of nano-graphite particles percentage on the spectral absorbance of the material was examined on samples containing two values of 1.5 and 2.5% nano-graphite particles by weight. Fourier transform spectroscopy (FTIR) analysis was also used to identify the functional groups in the developed material. A simple experimental setup was designed to evaluate the performance of the developed nanodispersed selective coating polymeric based material, by measuring the increase in temperature of circulating water. It was shown that adding 1.5–2.5% nano-graphite particles to a polymer based black coating causes an increase in the optical absorptance, and an increase in the circulating water temperature.

Mar 1, 2018

By W Baguley

Attritioning has been a method of improving mineral extraction for over 60 years, however it is only recently that an understanding of the mechanism employed and the improvement in efficiency that have been achieved.The paper will discuss these improvements and how to overcome the problems that have been raised. At present there is a dearth of information on the correct design and operation of these machines.The paper will address these issues as well as fluid on the Zeta potential, micro shear, retention residence time and pilot plant operation.A study on the hydrodynamics of attritioner operation has been identified and will be discussed.Surface chemistry, clean lines of attrition material and the treatment of fines significant advances in the understanding of attritioning highlighted.CITATION:Baguley, W, 2013. Attrition scrubbers, in Proceedings MetPlant 2013 , pp 229-246 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By F. Habashi

Chile is at present the largest copper and rhenium producer and was before World War I the largest nitrate producer. She is also an important producer of lithium carbonate and molybdenum oxide. An important event in the history of the country is the Pacific War of 1879-1883 in which she acquired the northern provinces initially belonged to Bolivia and Peru. In 1888 Chile annexed Easter Island. The Chilean mineral and cultural history is briefly reviewed together with the people who contributed to her development. The present report is the result of a number of academic and industrial visits to Chile during the period 1992 to 2009.

Jan 1, 2011