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By Alfred G. Hoyl

The author, in exploring a virgin area vertically in two known ore shoots requiring decline shaft sinking, drifting, crosscutting and diamond drilling, chose to use electric, electric hydraulic, and diesel rubber-tired equipment. A rebuilt hoist, and electric hydraulic shaft shovel (mucker), hydraulic sinking drills, single boom electric hydraulic jumbo, electric hydraulic LHD, and electric hydraulic diamond drill were used successfully. Slides of the equipment and its use are shown. The advantages and disadvantages of the equipment are discussed, together with costs and production.

Jan 1, 1984

Copper waste dump leaching is growing in importance because of the.large tonnages (up to 250,000 ton/day) of low grade waste rock available from open cut mining of copper deposits and proof that controlled leaching of copper from such dumps can be profitable.Overburden or waste rock, ranging in size from large boulders to fines, is dumped as cheaply as possible on sloping sites. Copper is leached from the dumps by applying up to 12,000 gal/min of leach solution (a combination of spent solution from cementation and make-up water) to the top of the dumps by various techniques.Efliuent from the dumps is sent to a cementation plant for copper recovery.Factors which may be controlled, either directly or indirectly, to give a controlled copper content in the dump efliuent (usually 1-2 g/l.) are the cycle of operations (i.e. the alternate wetting and drying periods), thevolume of solution applied to the dump, pH, Fe2+ and Fe3+ content or redox potential, oxygen content, bacteria and their necessary nutrients, and temperature.Dissolution of oxide copper minerals appears to be mainly a function of acid concentration. Copper sulphide minerals need oxidation for dissolution to occur and this is accomplished by a combination of oxygen,ferric ion, and bacteria. Oxidation of pyrite, oxidation of Fe2+ to Fe3 +, and hydrolysis of Fe3+ are of some importance in leaching practice. The presence of gangue carbonate minerals is detrimental.Physical factors connected with penetration of solution into large rocks are important and the treatment of an individual dump usually extends over a period of many years. Recovery of copper from solution is usually achieved by cementation with iron (usually in the form of crumpled cans) but the use of sponge iron is becoming more important. Iron consumption varies from 1 to 4 lbiron per pound of copper. Preconcentration of the copper in the efliuent solution by solvent extraction followed by electrolysis may become a useful method.Application of dump leaching techniques to metals other than copper depends on finding an economic method of recovering the metal from solution...

Jan 1, 1967

By MARSHALL D. DRAPER

CHINA is one of the large producers of the world's tin. About 95 per cent of the total Chinese production comes from the Kotchiu district in the southern part of the province of Yunnan. Yunnan occupies the southwestern part of China, bordering on Burma,. Siam and. French Indo-China. From the British port of Hong Kong,' small steamers sail southwest at about four-day intervals, reaching Haiphong in French Indo-China in two or three days. This, one of the principal ports in Indo-China, is a modern French city of some 50,000 population which, with its tropical surroundings, has much natural beauty. It is a few miles from the sea on the Red River, which has its source in China. Both at Haiphong and Hanoi, the capital of Indo-China, sixty-three miles north of Haiphong and also on' the Red River, there are foundries, shipyards, machine shops, cement and brick plants and various similar industries.

Jan 1, 1931

By R. V. Norris

1. INTRODUCTION. THE anthracite coal trade, with a shipment averaging about 70,000,000 tons per year, differs essentially from other coal business, in the fact that the larger sizes, comprising about 65 per cent. of the total, are used almost exclusively for domestic purposes, principally during the winter months; and that for proper combustion close-sizing is imperative, so that eight sizes are made; broken, egg, stove, and nut, known as prepared sizes, and pea, buckwheat, rice, and barley, known as steam sizes. These sizes are made in the regular course of preparation, and but little variation in the natural percentage of each is practicable. Thus it is necessary either to work the collieries intermittently, or to dispose of all the varying sizes in their fixed proportions. Unfortunately, the market does not at all times absorb the coal in proper proportions, and rather than interfere with the regular operation of the mines it has been found economical to provide storage for the excess. While the cellars of the consumers are the great storage-plants of the country, this capacity is not under the control of the trade, except so far as reduced prices during the spring and summer months may tempt the use of this reserve. The same remark applies but with less force to the retail yards, which,, though usually small, store in the aggregate a large amount of anthracite. While every effort is made to utilize to the utmost the individual storage-capacity of the country, there still remains the necessity for taking care of the irregularities of the market by the construction of storage-plants under the direct control of the producers. Such plants are usually the property of the railroads, and are situated at points most convenient from a traffic stand-point.

Jun 1, 1911

At Great Boulder Gold Mines Ltd. a number of attempts were made to remove water soluble copper and iron salts from calcined pyritic concentrates but variou~ problems arose and the methods were abandoned.A method of rapid washing has been developed and although some problems still exist a workable process was established which resulted in substantial savings of reagents used for the cyanidation of calcine.INTRODUCTIONIn the Great Boulder flowsheet crude ore is ground in cyanide solution, then thickened, agitated and subjected to two stage filtering. Secondary filter discharge is pulped with flotation circuit water, gassed with sulphur dioxide to precipitate soluble gold and activate pyrite, and after the addition of copper sulphate and xanthate, the pyrite and tellurides are recovered by flotation. Flotation tailings are thickened and pumped to the disposal area and concentrates are calcined in Edwards roasters. Calcine is washed to remove water soluble copper and iron salts and the washings pumped to the flotation section where the copper is used as an activator. The washed calcine is cyanided and returned to the crude ore circuit via the thickeners. Solution for precipitation in the Merrill Crowe is drawn from the crude ore thickeners.Prior to the introduction of calcine washing the calcine contained 7 lb/ton copper of which approximately 60 per cent was water soluble. It also contained approximately 90 lb/tol'l of water soluble iron salts. Both the copper and...

Jan 1, 1964

By E. J. Haas

DISCLAIMER The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health. Reference to specific brand names does not imply endorsement by the National Institute for Occupational Safety and Health. ABSTRACT Leadership is a critical component to an organization’s safety culture and influences the ways that health and safety is enacted on site. Therefore, it is not surprising that improving leadership will also improve safety. Worker perceptions of management practices are shaped through unique leader-employee interactions over time. However, few details are known about the communicative support (i.e., emotional, informational, and tangible) offered by supervisors and its impact on miners’ perceptions and performance. Using pre and post-interview data with 20 supervisors and 48 workers during six-week interventions, researchers identified positive and negative instances of supervisor support and its implications on worker performance. This paper highlights the common support tactics offered by supervisors and desired by workers to help practitioners identify ways to improve their safety culture and subsequently, the proactivity and compliance of their workforce. INTRODUCTION Supervisory leadership is a critical component to the effective implementation of an organization’s health and safety management system (HSMS). Specifically, supervisors serve as representatives of an organization and their actions are indicative of the organization’s safety culture (Eisenberger et al. 1986). Senior management has been shown to serve as a frame of reference for guiding safe behaviors in the workplace (Mearns et al. 1998) and, more recently, research has related supervisory enforcement to workers’ safety compliance (Petitta et al., 2017). Therefore, it is not surprising that by improving leadership, perceptions of management and subsequent safety outcomes are likely to improve as well (Zohar, 2002). Perceptions of management are shaped through unique leader-employee interactions over a period of time (Hofmann and Morgeson, 2004, 1999). How these unique interactions impact worker performance, however, remains unexamined. As a result, understanding how supervisor-employee relationships operate in high-risk environments is unclear (Mirza and Isha, 2017; Denis et al., 2010). A starting point to better recognize the idiosyncrasies of these relationships is by way of examining the communicative support offered by front-line management and received by industry workers. To this end, this paper uses pre- and post-interview data to study the communicative aspects of supervisor-employee interactions at mine sites. The analysis uses a social support framework to identify positive and negative instances of supportive communication. From interview data with 20 managers and 48 mineworkers, data emerged that shows how supervisors’ unique types of support contribute to workers’ perceptions, motivation, and follow-through of safe work behavior.

Jan 1, 2019

By Fred W. Snow

This paper describing the mining practices at the Magma mine, Superior, Ariz., is one of a series being prepared by the Bureau of Mines on mining prac¬tices, methods, and costs in the various mining districts in the United States. At present (1929) practically all the mineral production in the Superior district is from the Magma mine of the Magma Cooper Co. The ore is mined for its copper but contains associated silver and gold. Both direct smelting ore and ore of concentrating grade are produced. The mining methods now in use at the Magma mine were adopted or developed as knowledge was gained of the physical condition of the ore bodies and the inclosing formations; the wall rock is soft and crushed and the ore is relatively hard. In general, existing methods have been adapted to fit local conditions, but some of the mining practices used were originated at this mine. Most of the ore is mined by a combination of rill stopes and pillar stopes. The pillars are extracted by underhand mining.

Jan 1, 1929

By T. Muldoon

Literature review and extensive field survey of line and check curtain materials and practices showed: ? Miners, in general, know how to set tight curtains, and do so when needed. ? The tradeoff is economic; tight ventilation is labor-intensive. Line and check curtain techniques found are catalogued and evaluated. A fieldworthy 10 ft extensible brattice to maintain a 10 ft setback was found in use in two mines on continuous miner faces. This technique was evaluated in the laboratory for leakage and methane control at the face. Significant results include: 1) Air leakage through a gap in the extensible curtain depends upon the ratio of the cross-sectional areas between entry and return as well as gap area; 2) Gap shape has no significant effect on methane concentrations at the face -increasing gap area diminishes ventilation effectivness; and 3) Substantial reductions of CH4 concentrations at the face were accomplished by brattice extensions with gaps of up to 5 ft2 in area. An "inby hook," inserted in the roof automatically to make possible the deployment of a longer (20 ft) brattice extension in the context of a remotely controlled miner, was tested in various roof types. Insertion of this design succeeded only in coal.

Jan 1, 1982

By George B. Clark

COMMERCIAL strip mining of coal was first begun in the state of Illinois in 1911.1 The annual tonnage of coal produced from coal strip mines in the state was very small until 1924, when the strip mines shipped 1.68 pet of the total state shipping mine tonnage. Since then, strip mines have gradually come into their own by producing a sizable percentage of the coal produced in the state. Table 1 shows the coal tonnage shipped from both underground and strip coal mines in the state of Illinois for selected years. The table illustrates the major role that strip mines play in the state's coal industry. Today, strip mining is generally conducted in areas where the coal seams lie so close to the surface of earth that a stripping method of mining the coal seam is cheaper than an underground method. Strip mining not only recovers 100 pct of the coal deposit, but may also be used as a method of mining large acreages of coal abandoned by the closing of underground mines.

Jan 1, 1949

By Jr. Holmes

The Bureau of Mines drilled and sampled the more important magnesite deposits in the Currant Creek Mining District, White Pine County, Nev. The properties of the Ala-Mar Magnesium Co., Inc., and the Nevada Magnesite Co. were examined in August 1942 by D. W. Butner, engineer of the Bureau of Mines, to determine the advisability of investigating the deposits under the strategic minerals program. Development involving diamond drilling, trenching, and sampling was started September 1, 1942, and was completed in the latter part of November 1942. The deposits are on unsurveyed public land in T. 12N., B. 59 E., M.D.B.&M., in an area of high relief ranging from 7,300 to 8,100 feet in altitude. Both properties are situated northwest of the Tonopah-Ely Highway, U.S. Highway 6, from which a dirt road extends about 4.6 miles northwesterly, about 35 miles southwest of Ely, to the Ala-Mar property, and another dirt road extends about 10 miles westerly, about 26 miles southwest of Ely, to the Nevada Magnesite property. The magnesite occurs as irregular nodules, veins, and lenses in a bedded calcareous tuff formation, which overlies a group of volcanic rocks, and which is capped by remnants of rhyolite flows.

Jan 1, 1950

By Sydney H., Ball

ONE of the important mineral discoveries of the eighteenth century was , that of the Minas Geraes, Brazil; diamond fields. The production of this and of .other diamond discoveries in neighboring states made Brazil the premier producer of diamonds, succeeding India; its 140 years of supremacy finally passed to- South Africa- 60 years ago. Three times have diamonds contributed heavily to Portugal's somewhat checkered financial history; first in the sixteenth and seventeenth- centuries when the diamond trade of India was controlled by its citizens residing in ,Goa, later in the late eighteenth and the first 75 years of the nineteenth century when the Brazilian fields were the world's source of diamonds, and now, when the Angola diamond mines are the principal source of revenue of its colony, Portuguese West Africa. Certain phases in the history of the administration of the Brazilian field are sufficiently curious to warrant description.

Jan 1, 1929

By Bill Linville

During fiscal year 1969, the Bureau of Mines was engaged in 66 projects to improve methods for producing and utilizing petroleum. Programs directed toward the continued conservation of this natural resource, including crude oil, natural gas, and oil shale, were carried out through research performed at four laboratories supervised and supported by administrative personnel of this Bureau of the Department of the Interior. Over 100 technical papers and reports were published by the Bureau or others based on this research, and numerous other reports were prepared for U.S. Government agencies, State agencies, and organizations of the petroleum and natural gas industry engaged in cooperative research programs with the Bureau.

Jan 1, 1971

These tentative inspection standards have been prepared as a guide for the Federal inspection of the anthracite mines of the United States. The Federal Coal Mine Inspection Division is not a mining-law-enforcement

Jan 1, 1943

By Staff

A major emphasis of the U.S. Bureau of Mines is to perform research on the prevention of fatal accidents at mining operations. The leading cause of fatalities in the underground coal mining industry is groundfalls. This proceedings volume presents several new developments that are helping to prevent fatalities and reduce injuries by groundfalls. The papers focus on the problem from two different perspectives. About half of the papers present information and techniques that can be used to train and motivate miners to protect themselves from groundfalls. The other papers explain how to identify and respond to various geologic conditions that affect the stability of the mine roof. Of the 95 groundfall fatalities that occurred during 1986-90, 75% took place in Kentucky, West Virginia, and Virginia. The rate of groundfall fatalities was much higher at small mines. During 1986-90, the rate of groundfall fatalities at mines employing fewer than 20 people was 4.3 times higher than the rate for larger mines. Because so many groundfall fatalities are occurring at relatively small mines in the southern Appalachian coalfields, many of the papers focus specifically on the needs of this category of mine operations.

Jan 1, 1992

By John Paul Gries

This Bureau of Mines report reviews the mineral industry of the Black Hills area, including Butte, Custer, Fall River, Lawrence, Meade, and Penning- ton Counties, S. Dak.; and Crook, Niobrara, and Weston Counties, Wyo. It includes discussion of geological occurrence, processing, and potential of 27 commodities that have been produced from the nine-county area. The value of mineral production exceeds $70 million annually. Gold and petroleum account for two-thirds of the total, followed by clays, cement, sand and gravel, and rock. The combined mineral industries annually consume 268 million kilowatts of electrical energy, 933 million Mcf of gas, and 2 million barrels of fuel oil. Water consumption is about 10,000 gallons per minute. About 2,700 persons are employed on a year-round or significant part-time basis.

Jan 1, 1974

By Alan E. Renshaw

"This paper is a practical overview of ways to reduce cost in the design and operation of an Arctic mine. The economically important issues of the Arctic mine that will be addressed include: permafrost and the active zone in general terms; road building in and over permafrost; Arctic geotechnical mine design considerations; pit dewatering techniques in sub-zero temperatures; and blasting frozen materials with techniques to obtain optimal results. A final section on a few special topics conclude this paper.Although this paper primarily refers to near surface conditions more closely associated to an Arctic surface mine, many of the ideas and techniques contained in the paper also apply to the surface construction of an Arctic underground mine."

Jan 1, 1996

By L. O. Howard

THERE are three active mines in the Chewelah-Colville district, the United Silver Copper near Chewelah, and the Old Dominion and the Chloride Queen near Colville. The Admiral near Valley is also doing development work. The Chewelah district is in the south central part of Stevens County in the Colville Valley. Chewelah, a thriving town of 1600 people, and the scene of operations of the Northwest Magnesite Co., is about the center of the district. It is situated in a farming community on the Spokane-Nelson branch of the Great Northern railway, about 65 miles north of Spokane. Only two or three of the mines in the district have been extensively developed, although many have been prospected. The general elevation of the valley, is about 1600 or 1700 ft., that of the mountain ranges on each side about 3000 to 4000 ft., with gentle slopes and rounded glaciated tops. Prospecting is often difficult because of much glacial debris.

Jan 1, 1925

By R. W. Davis

INTRODUCTION CHURCHILL river was named for John Churchill, first Duke of Marl-borough and third Governor of the Hudson's Bay Company, in the latter part of the 17th century, some fifty years after the ill-fated Danish expedition, led by Munck, had abandoned the site of the now famous seaport of Churchill, as a worthless, cold, disease-ridden country. No other attempts were made to explore the interior until the river basin became a part of the grant to the Hudson's Bay Company and began to play its part in furnishing the luxury of fine furs to civilized people as it had furnished the necessities of food and dress for untold centuries to uncivilized natives. This was the sole contribution of the region to the economic life of the country for some two hundred and fifty years, until 1926, when the power site at Island Falls was discovered by engineers seeking a cheap power source to make possible the development of the great ore-body at Flin Flon. DRAINAGE BASIN OF CHURCHILL RIVER The river is some 1,325 miles long. Rising in the headwaters of the Beaver river, in east-central Alberta, it flows in an easterly direction across Saskatchewan and northeasterly across Manitoba to Hudson bay, through a remarkable basin of some 115,500 square miles, only 6,000 square miles less than the area of the British Isles. A journey down this river leads one through three distinct belts of country, each vastly different from the others geologically and in surface characteristics. For the first five hundred miles the river flows through a basin of 36,000 square miles of the great central-plains country, which is covered with fertile soil and carpeted in its southern part with prairie grass, which gradually gives way to the mixed forests of poplar, spruce, birch, and jackpine in the northern and eastern sections: About midway across Saskatchewan, bald-headed knolls and ridges begin to make their appearance as the river meets the western margin of the Canadian Shield. Then, for some seven hundred miles, it passes through country underlain by the pre-Cambrian rocks of the Shield, which continue to within one hundred miles of Hudson bay. Here the character of the country again changes to a low, clay plain underlain by sandstone, and through this 'clay belt' the river flows between steep clay banks, to empty into Hudson bay.

Jan 1, 1935

By Robert A. Westin

Polychlorinated Biphenyls (PCBs) have been widely used as fire resistant dielectri coolants in electrical equipment used in mining applications, including transformers capacitors, electric motors, and electromagnets. In addition, PCBs have been used in hydraulic fluids and heat transfer fluids, and are present in many oil filled transformers. The Environmental Protection Agency recently banned the manufacture of PCBs and equipment using PCBs, and imposed strict requirements on the continued use and disposal of existing PCB equipment. This manual discusses the EPA requirements, suggest ways to decrease the risks resulting from continued use of PCB equipment, and surveys the non-PCB equipment that is available as replacements for the PCB electrical equipment presently used in mines.

Jan 1, 1979

By Robert C. Stanley

The prominence of her mineral resources makes Canada a most fitting place in which to hold the Second Empire Mining and Metallurgical Congress, since in all probability the Dominion has more diversified mineral wealth than any other part of the British Empire. This paper is concerned with nickel, an important factor of Canada's mineral production. The richness and quantity of her nickel ores have made Canada the world's most important source of supply of the metal. Its history and diversified uses are, therefore, particularly interesting at this meeting. Early History Probably the first use of nickel by man was in the fashioning of implements, and later swords, from nickel-bearing meteorites, masses of metal that have fallen from time to time at many points on the earth's surface and which consist normally of iron carrying substantial amounts of nickel. Meteorites were perhaps the first metal known to man. The falling star, sought out with fear overborne by curiosity, was found to be a better stone than the earth-given, truly a boon from the gods. Archaeologists tell us there is good evidence that the ancient oriental peoples learned at an early date to make these stones into useful implements. The invincible blades of the great warriors of old, in China, Persia, and in northern Europe, were Heaven-sent, a fable which sounds significant of meteoric iron. Probably some of the ancient swords of Khorassan and of Damascus were of meteoric nickel-bearing iron.

Jan 1, 1927