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By E. J. Gleim

[THE ORGANIC act under which Federal Bureau of Mines was established provided for the investigation of the safe use of electricity in mines. Each Congress appropriates funds for conducting this investigation. As part of this investigation, electrical apparatus used in mines is studied to determine if its operation and use might introduce a hazard. From this study, certain safety standards have been developed. These standards, established with the aid of both the manufacturer and user of such apparatus, are published in schedules, and apparatus that complies with the requirements set forth these schedules is classified as "permissible." This term is defined to designate apparatus as "completely assembled and conforming in every respect with the design formally approved by the Bureau of Mines." In the judgment of the Bureau, the manufacturers of such apparatus have adhered to certain minimum standards of safety in supplying a product that when properly used and maintained is safe for operation in mines where flammable gas or coal dust may accumulate. This work of the Bureau of Mines for increasing safety does not make it obligatory for manufacturers of mine equipment to produce only that of permissible classification. Before the effective date of the Federal Mine Safety Code,5 the Bureau sought to promote safety by recommending that mine operators install permissible equipment in gassy mines as a preventive measure against gas and dust explosions initiated by electrical equipment. For some years, the mining laws of several States have prescribed the conditions under which permissible equipment must be used. The Federal Mine Safety Code requires that ?all new electric face equipment and replacements of equipment purchased for mines where nonpermissible equipment is now being used shall be of a permissible type approved by the United States Bureau of Mines,]

Jan 1, 1955

By Braden Schmidt

The following full paper will go into the products, techniques and people who work in the avalanche control industry giving insight to the other members of the ISEE an overview of the niche blasting that is Avalanche Control.

Feb 1, 2020

By S S. Kahlon

India is a large and growth market for explosives and accessories, which has dramatically changed from complete import dependence to self sufficiency, and now has an exportable surplus. The largest single user is coal mining which is continuing to show a healthy growth with opencast mining becoming increasingly dominant. The explosives industry has kept pace with mining and today all the well renowned explosives technologies of the world are available in the country. While slurry explosives are popular in large diameter, NG based explosives continue to be preferrred in small diameter usage. Emulsion explosives have had a good market response. ANFO usage is limited due to local reasons. As the mine size is increasing, the demand for bulk-on-site explosives is growing. Prices of explosives and accessories are cheap compared to international levels. The user industry is mainly Government owned mines whose profitability is not satisfactory. Explosives industry is over licensed in terms of manufacturing capacity, which is likely to put pressure on the viability of some of the explosives manufacturing units. Scope exists for optimization of blasting parameters through the use of computerized blasting models. The explosives industry is faced with new challenges and opportunities.

Jan 1, 1987

By Pramod C. Thakur

During the past ten years, the US coal industry has experimented with various ways to extract methane from coal seams. Drilling long horizontal boreholes in solid coal from mine workings and vertical gob degas boreholes are becoming standard techniques for methane recovery from coal seams. Prime motivations for such work have always been safety and productivity in mines, but the commercial value of gas so produced is encouraging utilization. The paper reviews various ways to produce methane from coal seams and discusses some utilization projects extant in the industry.

Jan 1, 1984

By G. Akdogan, C. Dorfling, L. Bumhira

Hydrometallurgical recovery of rare earth elements from phosphors obtained from end-of-life fluorescent lamps involve leaching followed by extraction of dissolved metals from solution. The similar properties of rare earth elements make selective recovery of individual elements challenging. The aim of the paper was to investigate the extraction of primarily Ce and Tb from a hydrochloric acid leach solution also containing other REEs (Y and Eu) as well as impurity metals (Ca and Al). Batch solvent extraction tests were performed with di-(2-ethylhexyl) phosphoric acid (DEHPA) at various extractant concentrations, pH conditions and organic-to-aqueous ratios. Extraction isotherms and separation factors for the range of conditions tested in the project are presented in the paper. Separation of individual REEs was not possible at the conditions investigated, but a mixed REE product can be obtained in a single extraction stage operated at a pH of 0.5 using 1 M extractant at an O/A ratio of 1; these conditions resulted in complete Y and Eu, 95 % Ce and 99 % Tb extraction with Ca and Al coextraction below 7 %. A better quality mixed REE product can be produced by operating at lower pH and extractant concentration conditions, but this would require a larger number of extraction stages. Keywords: Cerium, fluorescent lamps, phosphors, rare earth elements, solvent extraction, terbium

Jan 1, 2020

By N. Melnyk, H W. Habgood

The conventional low temperature process for extracting' helium from natural gas involves liquefying the whole gas stream in order to remove the relatively small fraction of helium. A process based on the selective diffusion of helium through a semi-permeable barrier is, in principle, more economical and flexible, particularly for the treatment of small re-serves and low concentrations. The well-known permeability of glass to helium offers the possibility of such a diffusion process and McAfee of the Bell telephone Laboratories showed in 1958 that practical separations could be achieved by passing natural gas over bundles of fine capillary glass tubing. Developmental studies have been carried out involving larger units and more extended field tests than those of McAfee. Fine capillary tubing of Pyrex glass 0.0035 in. diameter was prepared by drawing ordinary 6 mm. laboratory tubing in a furnace. Extraction units were pre-pared containing about 10,000 such tubes, 4 ft. long and cemented inside

Jan 1, 1961

By Jafar Safarian

Bauxite is the main raw material used for the production of alumina (Al2O3) through the well-known commercial Bayer process. This process has significant challenges such as limitation in using low-grade bauxites as they contain significant amounts of impurities such as Fe, Si, Ti. The Bayer process residue, which is known as red mud, is also a global environmental challenge due to huge amount of this low value residue production. An alternative sustainable process with high potential to solve these problems and produce valuable and consumable by-products is a pyrometallurgical-hydrometallurgical process in which the low-grade bauxite ore is treated through a smelting-reduction process, yielding iron alloys and a calcium-aluminate slag. Alumina is then produced from the slag by hydrometallurgical treatment. In the present work, the reduction of pellets produced from different bauxite ores by hydrogen is studied and it is shown that complete iron oxides reduction is possible. Further smelting and smelting-aluminothermic reduction of the reduced pellets show that iron and silicon ferroalloys can be produced, in addition to a proper slag for alumina extraction.

By H. A. Shaw, H. G. G. Whitton

This paper describes the use of the electric-arc furnace for the production of tough-pitch, horizontal cast copper shapes and the production of copper anodes from tank house anode scrap. This installation is the only one of its kind in the United States. SINCE the initial use of electric-arc furnaces for refined copper melting on a commercial scale at Copper Cliff in 1936, this type of melting has been of extreme interest to everyone in any way connected with copper casting and fabricating. Early in 1948, Kennecott Copper Corp. decided to build an electrolytic copper refinery at Garfield, Utah. One of the major decisions to be made at that time was the type of furnace to be used for melting cathodes for casting into refined copper shapes and for melting anode scrap for the production of anodes. Based on the results obtained from arc furnaces by the Tnternational Nickel Co. of Canada, at Copper Cliff, and by the American Smelting and Refining Co., at Baltimore, coupled with certain important economic factors such as having an adequate amount of relatively cheap power available at the Magna Central Power Plant, high cost of poles and oil in the Salt Lake District, and the lack of natural gas at that time, the final decision was to install electric-arc furnaces rather than the standard type of rever-beratory furnaces. Experience has shown certain parts of the original installation to have been inadequate or in need of modification. Although the present status of arc-furnace melting at the Utah Refinery is far from perfect, nevertheless substantial progress has been made. At the Utah refinery, copper is melted in three 15-ft diam, size "M" Lectromelt furnaces, two of which are used for melting cathodes and one for remelting anode scrap. Each furnace is energized from a 13,800-225 v, 3-phase, 60-cycle, 6000-kva (at 40°C rise) oil-immersed water-cooled transformer. Auxiliary equipment for each refined copper furnace includes a charging machine, launders, ladle, 40 ft diam Walker-type casting wheel, bosh, and inspection conveyor. The anode furnace differs in that it is charged by hand from an elevated platform and the anodes are picked off the 24-ft diam casting wheel by a takeoff hoist and loaded directly into specially designed trailers, Figs. 1 and 2. Electrical Equipment Electric power to operate the arc furnaces is generated at the Kennecott-owned Magna Central Power Station two miles distant and transmitted to the Refinery outdoor substation at 44,000 v. At this point it is stepped down to 13,800 v and carried through concrete-lined underground tunnels to the switchgear and then to the primary side of the furnace transformers. The power is conducted from the Y-connected secondary bus bars of the transformer to the electrode arms by means of 22 flexible copper cable conductors per phase. Each cable has a cross-sectional area of 1,750,000 circular mils, giving a total area of 38,500,000 circular mils per phase. The power is carried from these cables to the three individual electrode holders by means of water-cooled copper bus tubing. The electrode clamps are incorporated in the electrode holders and are released by air pressure working against a spring in the clamp control cylinder. The movement of the electrode arms is either automatic or manual. The automatic control is used during melting and is regulated by three Westing-

Jan 1, 1954

By J. R. Stone, G. D. Storm

Design features and operating methods of ASARCO's new unit for the continuous melting and casting of tough pitch copper at Perth Amboy are described. Preliminary studies made for determinitzg economic feasibility and design details are also presented. Cathodes are preheated with oil and melted in an electric furnace at 40-ton per hr rate, from whence the molten copper is fed simultaneously to the wire bar casting wheel and the continuous casting of cakes and billets. In the early 1950's the copper refining furnaces at ASARCO's Perth Amboy plant reached a point where major expenditures would have to be made for replacement of the furnaces and the auxiliary equipment. The problem was whether to continue with the standard reverberatory furnaces or to consider continuous melting in electric furnaces. Reverberatory furnaces have been used for years in the copper industry and for some 50 years at the Perth Amboy plant. Reverberatory melting practice, however, imposes certain restrictions. First, labor costs are high, usually requiring three shifts per day. Secondly, they operate on a batch basis, the conventional operation being a 24-hr cycle including

Jan 1, 1961

The Ural Mountains, which were formerly the dividing line between Asia and Siberia, area chain of low mountains, the highest peaks reaching only a little over 5000 ft. The country has been much eroded and the mountains now appear as rounded hills. In the central and northern parts turf swamps abound. The range is covered with forests except at the extreme southern end. The trees are mostly pine. Birch grows on cut-over areas, but never to large size. The rivers are small or the fall is slight, so no large water powers are available. A series of rivers with a north and south course, and which are navigable for long distances, furnish cheap transportation during the summer months. Railroad communications are very insufficient. The first active exploitation of the mineral wealth was initiated by Peter the Great, who sought iron and copper for use in his wars against the Swedes. He selected a blacksmith named Demidoff to supervise operations and gave him rights to most of the Ural and to the Altai. The Nijni Tagil Estates are still in the possession of the Demidoff family. The original large grant was subsequently subdivided through inheritance and marriage, but the Ural is still a country of very large estates, some of them held as leases only and some of them by actual ownership.

Jan 6, 1919

By NEWTON B. KNOX

THE war has forced the principal industrial nations of the' world into the strait jacket of a closely controlled economy; taxes have been heaped upon all enterprises in order to maintain the armed forces and to deprive the people of the ability to bid for goods now unavailable. These restrictions, controls, and taxes are unlikely to disappear entirely after the war has been won, for debts will remain to be paid with a long period of difficult readjustment. Although the new economy will doubtless offer plentiful opportunities for the advantageous use of capital, no investor can ignore the favorable conditions offered by industry in Latin America, where taxes are relatively low and the restrictions on free enterprise comparatively mild. In mining in South America, the great international corporations have

Jan 1, 1944

By George A. Miller

ALTHOUGH the Andean mountain belt, which contains almost all the metal deposits of the other South American nations, does not enter Brazil, this country is rich in mineral resources, for in area it accounts for half the continent and geologically it contains almost all of the Brazilian Shield. This great mass of ancient rocks has been relatively stable for a long time and forms a great area of plateaus and highlands interrupted only by the syncline which carries the Amazon River across it to the sea. Lowland Brazil - the great flood plains of the Amazon. Tocantins, Paraguay, and Parana Rivers-is of no interest to the miner, and in fact supports but a small proportion of the country's population. The highland area is divided into unequal parts by the Amazon River; the north half is underlain by the north lobe of the Brazilian Shield which extends into Venezuela as far as the Orinoco, and into the Guianas, and is known as the Guiana Highlands. Mineralization appears to have been weak in the Brazilian portion of these hills. In fact most of the ore deposits are to be found in the States of Minas Gerais and Bahia, although the neighboring states of Sao Paulo, Pernambuco, and Piauhy can also boast of some deposits. Goias and Matto Grosso are as yet incompletely prospected but are considered to contain reserves for the future.

Jan 1, 1945

By NEWTON B. KNOX

THE Guianas region is a geological unit, consisting of the northern lobe of the Brazilian Shield, but political accident and the fact that rivers act as the principal means of transportation have divided the region between five separate sovereignties. Brazilian and Venezuelan Guiana have already been considered. The French, Dutch, and British colonies consist of a coastal plain some fifty miles wide, which, together with the lower reaches of the principal rivers, support the greater part of the population. Inland from this tidewater region is a wide area of low, forest-covered hills, under-lain by gneisses, schists, granites, and pegmatites of the Shield. As in Venezuelan Guiana, these rocks are overlain by a thick series of horizontal continental sediments intruded by moderately basic magmas. Gold, bauxite and diamonds have been the principal products of the colonies. The first metal is quite widespread in the hill country. The quartz mines are small, though occasionally rich; probably the greater number of veins remain undiscovered because of the thick mantle of decomposition product that covers the schists and gneisses. The greater proportion of the gold, therefore, is derived from placers which are exploited in all three colonies. Some geologists claim that they occur in two belts parallel to the coast; whether this feature has its origin in the location of the primary mineralization or in the gradients of the rivers is not clear. In some instances the river gravels grade into auriferous laterite. The laterites are well developed in the Guianas and represent the weathering products of the more basic rocks.

Jan 1, 1946

By W. G. SWART

THE best estimate on reserves of iron ore in the Lake Superior district is that made, in 1920, by Mr. R. C. Allen, amounting to 2,947,225,000 tons of assured and probable ore. This includes direct- shipping or so-called merchantable ores, and those capable of beneficiation by demonstrated processes. De- ducting from this the 287,000,000 tons shipped since 1920, leaves a present reserve of approximately 2,500,- 000,000 tons, or; about 50 years' supply. The assured ore in this estimate is given as 1,560,500,000 tons, which checks Mr. Lake's estimate of 1,528,948,000 tons, or about 30 years' supply. This is not a long time in the life of the steel industry, and it can be readily appreciated that the matter is important enough to war- rant the attention it is beginning to receive. The first question that engages our attention is, What is merchantable ore? In 1902 the average of all Mesabi shipments was 56.07 per cent iron and 4.35 per cent silica. Twenty-five years later it had dropped to 51.99 per cent iron, with silica up to 7.92 per cent. It has remained around these figures for' ten or twelve years and, except for a probable rise in silica, can stay there for an indefinite period. Most of these figures I am giving cover the Mesabi Range. Including the other ranges does not change the figures greatly, and the Mesabi Range commands the situation, since it produces about 65 per cent of the total annual tonnage and, according to Mr. Allen, contains 81 per cent of the assured reserves, 50 per cent of the probable reserves, and 66 per cent of both the assured and the probable reserves.

Jan 1, 1926

By L. M. Luckevich

Gypsum is a product from the neutralization of sulfuric acid by lime or limestone. This paper will discuss specifications for gypsum used in wallboard, cement and agriculture and the factors affecting its utilization potential. Process conditions during the neutralization which enhance or inhibit utilization potential will be included. In addition, this paper provides a technical and economic perspective of the gypsum industry in North America with a view to the factors affecting the utilization of synthetic gypsum in traditional applications. Current production and consumption of natural and synthetic gypsum in Nonh America are described and the impact of their differences on utilization options are discussed.

Jan 1, 1996

By R. Laird Auchmuty

A NUMBER of factors, of varying importance, should be considered in assessing mineral land-here specifically coal land -for tax purposes. (1) Is the coal developed or un- developed'! (2) If undeveloped, is it surrounded by active development in adjoining properties? (3) Accessibility of railroad facilities to the property. Sometimes the railroad itself is of importance. (4) Cost of development of the seam under consideration, whether it can be developed by a drift from the outcrop or whether it will require deep and costly shafts or slopes. (5) Is it definitely known that the coal seam being assessed is of minable thickness and quality on the property? (6) Thickness of recoverable coal from the seam. (7) Quality of the coal. (8) Is the seam being assessed likely to be more costly to mine than other seams in the same district? (9) Is there an active market demand for coal from the seam being assessed? (10) Is the coal held only as protection to surface structures and in such location that it can never be mined? (11) Is the coal in a solid piece or is it in pillars that have been standing for some years as a result of incomplete mining in an old operation? (12) Expected percentage of recovery from the seam being assessed as determined by present mining practice in similar properties. (13) Value of the seam as indicated by sales of similar mineral rights in the immediate district. (14) Current royalty rates of leases for coal in the seam under consideration.

Jan 1, 1939

Data recently released indicate substantial improvement in mineral industry performance for 1984. Business plans to increase plant and equipment spending in 1984 by 14.8 percent, according to a recent survey conducted by the Commerce Department's Bureau of Economic Analysis (table 1). In contrast, capital spending by all industries declined 4.8 percent in 1983 and 2.3 percent in 1982. The latest estimate of planned expenditures for 1984 is $2.2 billion higher than the comparable estimate based on the survey conducted in late January and February 1984.1/ [ ] Of particular significance to the U.S. mineral industries are the 15.5-percent increase in capital spending planned by manufacturing in 1984 and the planned 18.6-percent increase in spending by durable goods manufacturing, where the largest increases are planned in the transportation equipment (26.4 percent) and electrical machinery sectors (23.5 percent). Capital expenditures in manufacturing declined in both 1982 and 1983.

Jan 1, 1984

By Mario Gerards, Marco Steinberg, Jan Huben

"Wet high intensity magnetic separation or WHIMS is a widely used technical process for the recovery of magnetic susceptible iron ore particles, mostly for fine and ultrafine grain sizes. The JONES® WHIMS - Wet High Intensity Magnetic Separator, has been used for many years and in countries all around the world. This paper outlines the physical principles utilized for the separation inside the unit, as well as some of the recent changes and developments on the design. It will also give an outlook on the theoretical potential of different alternative yoke materials. The aim of this paper is to analyse the suitability of different yoke materials to improve the equipment. This will be done comparing the magnetic and mechanical parameters and analysing availability and price to find the best compromise regarding cost and benefit. As far as the different kinds of materials are concerned, a special material has been identified as suitable during the comparison exercise. After running the economical calculations, especially with respect to the reduction of the total power consumption of the equipment, a tremendous reduction of the total power consumption has been determined. In addition, to the theoretical exercises and due to the promising results of the same, the Pilot Unit P 40 of the JONES® WHIMS has been manufactured with the special material in order to get practical results as well. Finally, this paper outlines the theoretical and practical results focused on the power consumption. The results are showing that the total power consumption can be reduced tremendously. Hence, the way for a new generation of JONES® WHIMS - environmentally friendly - has been paved."

Jan 1, 2014

By Gus L. Maciula

Although I will briefly review the current status of coal slurry pipeline technology, I wish to make it clear that this is not a technical paper. It is intended instead to review the current situation on energy resources and requirements, and the environmental, political and economic considerations that mandate a serious consideration of Slurry pipelines as a viable mode of coal transportation into the Georgia and Florida markets. In order to more fully appreciate our current energy situation, it will be helpful to go back a few years and review the evolution of our so-called energy "problem." It was about two decades ago that the first and only major natural gas transmission pipeline was built into the State of Florida by Florida Gas Company. This line was conceived and implemented during a time when gas was plentiful and cheap, and it appeared at that time that unlimited gas reserves were continually being discovered, thus assuring the availability of a clean, cheap fuel and the ,viability of the pipeline system. One of the major factors justifying the original pipeline construction as well as subsequent expansions was a series of long-term commitments under which Florida Gas transported natural gas owned by electric utilities for use as boiler fuel. Thus for the past 20 years Florida industry, commerce, and domestic fuel requirements have been met either directly or indirectly through clean, cheap natural gas which would not have been otherwise available without the pipeline system.

Jan 1, 1978

By H. X. Li, A. Correa, M. M. Zhang, W. Xuan, M. Andrade

"With increasing demand for steel and depletion of high-grade iron ore deposits, more research efforts are being directed toward extending the life of existing ore reserves and developing technology to treat low-grade iron ore resources. Among all the reported technologies, biotechnologies in mineral processing – specifically bioleaching and microbially induced flotation – have emerged to be considered as low-cost, environmentally friendly potential alternatives to many of the current mineral processing techniques. This paper provides a comprehensive review of current research on the use of microorganisms for iron ore beneficiation and, further, discusses the applicability of bioleaching, bioflotation and bioflocculation for the beneficiation of low-grade iron ores.IntroductionIncreasing global demand for raw materials has led to diminishing resources of high-grade iron ore. As a result, the mining and utilization of low-grade hematite, limonite, specularite, siderite and goethite ores have attracted more and more attention. However, these types of iron ores are of complex paragenesis and fine disseminated grain size, and often contaminated by phosphorus in the form of solid solution. The distribution of phosphorus throughout the iron mineral crystals prevents the effective use of physical separation techniques, and these complex ores are at present largely untapped due to a lack of cost-effective and efficient processing methods. Chemical leaching and roasting-magnetic separation approaches have been mainly tested only on the laboratory scale and are all either cost prohibitive or ineffective when used on low-grade complex iron ores."

Jan 1, 2015