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By D. Richers

When modeling predictive pit lake chemistry, groundwater chemistry is integrated with the affected portions of the wall rock and chemistry of the lake in a complex series of mixing. Fractions of the solutions impinge upon fresh, unaltered or fractured and oxidized zones of the wall containing sulfide materials and/or soluble metal/metalloid salts. Changing conditions over the short term (biannually) and long term (decades) can drive reactions allowing for dissolution or precipitation of acid rock drainage and metal leaching (ARD/ML) constituents. Local zonal variations can result in a portion of the pit releasing materials into solution; whereas other portions of the lake might favor the formation of colloids or precipitants. The proportions and character of groundwater can drive the chemistry of the pit lake provided sufficient buffering capacity is available to temper the generation of ARD in the system. For sulfide-rich systems, reduction of oxygen by rapid inundation and consumption by sulfides is key to reducing the ARD/ML. This paper presents several models of a sulfide-rich wall rock system using a range of groundwater chemistries to show these constraints.

Jan 1, 2012

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The course has been broadened in scope, revised, and brought up to date and is being published as a similar series of seven miners' circulars (Nos. 51-57, revised) on accident prevention in metal and non-metallic mines. These circulars are as follows: Injury Statistics (Miners' Circular 51), dealing with general statistics on injuries from accidents at metal and nonmetallic mines, including causes, costs, and the use of investigations and reports of all injuries.

Jan 1, 1960

By Donald D. Murphy

My first contact with underground, bolt conveyors came when I was hired as a draftsman by the La-Del Conveyor & Manufacturing Company in 1935. At that tine relatively few nines were using haulage belt conveyors. Wore they were in use, they were usually loaded by chain or shaker type room conveyors which in turn were hand loaded at the working face. Duo to the low room tonnage, a gathering belt might receive who output of from six to eight rooms. For several years belts 26 and 30" in width were the favorites for coal mine use. Belt speeds very seldom exceeded 200 ft. per mm. at that time. Conveyor lengths for the majority of units lay between 1.000 and 2000 ft. For a number of years 25 H.P. drives were adequate for those conveyors. From 1940 until about 1950 loads and speeds went up slightly and 40 H.P. drives became the standard. Since the majority of mines were then using direct current power systems, we were able to use controllers with 3 or more steps of starting resistance. The slow belt speeds coupled with relatively long starting cycles kept the rate of acceleration low and gave us smooth, easy starts.

Jan 1, 1963

By S. Rajendran

The area of the Exclusive Economic Zone (EEZ) of India is about 2.014 million km2 and the resource evaluation of placer deposits is one of the objectives of Government of India. Placers are detrital metallic minerals found on beaches and in the near shore areas. Quantitatively more important are placer deposits of light heavy minerals such as zircon, ilmenite and rutile. Rivers and other drainage channels are the main carriers of the placers which contain heavy minerals like magnetite, ilmenite, garnet, zircon, monazite, rutile etc. The present beach as well as part of the shelf was land during Pleistocene as a result of the world wide lowering of the sea levels. The coast line shifted a number of times. Hence, the heavy mineral placers on the beaches are expected to extend to offshore areas chiefly with Pleistocene lowered sea level strands. India has extensive deposits of heavy mineral placers along the beaches. Placer deposits of heavy minerals occur in discontinuous patches on the beaches along many parts of the east and west coasts. Along the central west coast of India (12??N - 19? N lat.) the placer containing 14 - 17% ilmenite form an estimated reserve of 4 million tons. On the Ratnagiri coast of Maharashtra, the proportion of heavy mineral varies between 54 and 70% in the bulk samples, consisting mainly of 14 - 39% magnetite and 16 - 30% ilmenite. The National Institute of Oceanography (NIO) surveys show that the sediments off the central west coast consist largely of silty sand, sand silt and clay. The core samples show that a reddish brown clay overlay olive gray clay which in turn overlay heavy mineral rich sands. The heavy mineral concentration ranges upto 90% and has mainly ilmenite and magnetite with minor quantities of apatite, rutile, zircon, kyanite etc. Siddiquie et al. reported 42 - 75% TiO2 in the ilmenite.

Jan 1, 1998

Study on Beneficiation Technology of a Refractory Fluorite Ore in North China

Sep 13, 2010

By X. B. Zhao, J. G. Cai

The purpose of this paper is to incorporate the dynamic BB model of rock fracture normal behaviour into Universal Distinct Element Code (UDEC), and to conduct UDEC modelling to predict stress wave propagation across rock fractures. With the incorporation of new dynamic model of fractures, the UDEC is improved in the capability of modelling wave propagation across fractures. In this study, the case of normally incident P-wave transmission across a fracture is modelled, and the effect of dynamic normal behaviour of fracture is concentrated on. Wave transmission coefficient for wave transmission across the fracture with the dynamic BB model is obtained for various combinations of fracture dynamic parameters, as well as different wave amplitudes and frequencies.

Jan 1, 2003

By E. D. Gardner

This paper on the square-set system of mining embodies the results of a special study of the subject made as a part of the Bureau of Mines general investigation of mining methods and costs. Data for the paper were gathered by the authors during visits to mines using square-set mining, from Information Circulars prepared by consulting engineers to the Bureau on mining methods at individual mines, and from articles in the technical press and the Transactions of the American Institute of Mining and Metallurgical Engineers. The square-set system of mining is very widely applied and is one of the oldest methods in use in the United States. It is mainly employed for extracting relatively high-grade ore in heavy ground. It is also useful in taking out pillars left in mining by other methods. It is used to some extent as an auxiliary method with many underground systems and as an alternate with cut-and-fill, shrinkage, and open-stope methods when heavy ground is encountered. In some cases as much as 50 per cent of the ore may be extracted by square-setting at mines listed as using some other method of mining. A large tonnage is mined yearly by square-setting, principally in the Western States.

Jan 1, 1933

LARGE-SCALE production of zirconium by the Northwest Electrodevelopment Laboratory of the Bureau of Mines at Albany, Oreg., is an anomaly that justifies some explanation. The reduction of titanium tetrachloride with magnesium in an inert atmosphere, as perfected by Dr. W. J. Kroll before 1940, aroused renewed interest in zirconium, and in 1945 development work on this metal was initiated at Albany under Dr. Kroll's technical direction. Preliminary results were promising, and in February 1947 a pilot plant with a weekly capacity of 60 pounds of zirconium-metal sponge was put in operation. Shortly thereafter the Oak Ridge National Laboratory of the Atomic Energy Commission requested production of 1 ton of zirconium-metal sheet, with the provision that it have a low hafnium content. The Bureau of Mines was furnished with a. supply of Brazilian baddeleyite ore, containing less than 1 percent hafnium with respect to zirconium, from which was made about. 2,700 pounds of relatively low hafnium zirconium sheet of 0.080-inch thickness for test purposes. This was accomplished by melting zirconium sponge in a graphite crucible, hot-rolling the ingot in an iron sheath, and finishing by cold rolling. Concomitantly the Oak Ridge Laboratory developed a method for separating hafnium from zirconium; and, in cooperation with the Atomic Energy Commission and the Bureau of Ships of the Department of the Navy, a, larger pilot plant was erected to produce zirconium from very low hafnium zirconium tetrachloride furnished by the Commission. Pilot-plant work on producing zirconium tetrachloride from zircon sand and baddeleyite was discontinued. Production of zirconium sponge in the larger pilot plant of 500 pounds per week capacity was begun in June 1949.

Jan 1, 1956

By Paul C. Hyndman

The U.S. Bureau of Mines investigations of the three subunits (fig. 1) of the Homestead RARE II area (No. 6291) revealed no evidence of mining activity or mineral deposits in the area. The Iron Dyke Mine, 3 mi (5 km) outside the study area produced ore between 1916 and early 1982 from a volcanogenic massive sulfide deposit in the Permian volcaniclastic Hunsaker Creek Formation of the Seven Devils Group. The Hunsaker Creek Formation does not crop out in the RARE II area, but extends into the area beneath Miocene flows of Columbia River Basalt. The abundant basalt in the area could be used as aggregate or dimension stone, but equivalent deposits exist closer to markets. INTRODUCTION Location and Access The Homestead RARE II area (fig. 1) encompasses 6260 net acres (253U ha), in three units, of the Wallowa-Whitman National Forest in Baker and Wallowa Counties, Oregon. Two small units of 160 and 300 acres (65 and 120 ha) are 5 mi (8 km) north and east of the main study area. Homestead, Oregon, on the Snake River, is about 3 mi (4 km) south of the two small areas, and about 3 mi (4 km) northeast of the main study area. Peripheral access is provided by State Highway 86, U.S. Forest Service Road 39, and ancillary roads and trails.

Jan 1, 1983

By R. K. Wharton

The paper reviews the development of European harmonised standards for fireworks, recent major incidents involving the bulk storage of fireworks which led to research funded by the European Commission, progress with the forthcoming European Regulation on pyrotechnics and potential issues relating to the certification of products within the scope of the new Regulation.

Jan 1, 2005

By Donald J. Barnes

There are no producing or developing mines in the study area. The only mineral production was stone from a basalt deposit near Indian View Point. Cinders and sand and gravel have been produced from deposits within 1/2 mi (0.8 km) of the boundary. Stone, sand and gravel, and cinder deposits inside the area are not considered resources because equal or better quality material is found closer to markets. The study area has no known oil and gas, coal, geothermal, or other energy related deposits. However, in 1982 application was filed on 25,000 acres (10,125 ha) of petroleum and on 15,000 acres; (6,0/5 ha) of geothermal leases.

Jan 1, 1983

By J. Flemming, R. O. Burt

"The Tanco pegmatite is located in the Bird River greenstone belt of southeastern Manitoba approximately 160 km northeast of Winnipeg (Figure 1). This pegmatite body was discovered in 1929 and subsequently attempts were made to exploit it for tin by Jack Nutt Mines Ltd. and later in the middle 1950's by Montgary Oil Ltd., who extensively developed but did not produce from, its lithium deposits. In 1966 systematic investigation of the pegmatite as a potential source of tantalum led to the founding of Tantalum Mining Corporation of Canada Ltd. (TANGO) in 1967 and production of tantalum concentrates from the Bernie Lake mine commenced in 1969. Tanco is currently jointly owned by Hudson Bay Mining and Smelting Co., Cabot Beryl co Inc. of Boston, and the Province of Manitoba. (Williams and others 1978, Burt 1979, Burt and others 1982), continued until the end of 1982, when, due to falling demand and prices, operations were suspended.During the 1970's Tanco had investigated the potential of the lithium orebody; carrying our research into both the concentration of the ore and into the production of lithium chemicals. However lithium chemicals were in an over-supply situation, due in part to the production from Chilean brine deposits (Buckley, 1983), and Tanco' s own plans were put into abeyance. The potential alternative market, the direct use of concentrates in the glass and ceramics industry, did not at the time justify the cost of constructing a new plant."

Jan 1, 1986

By W. J. Taylor

Nature has furnished us with fuel in three forms, solid, liquid, and gaseous; solid, the most common; liquid, containing the greatest energy; gaseous, the most convenient for use. The tendency of the day is to the conversion of solid and liquid fuel into the gaseous form. There is magic in the word gas to many men who through ignorance or indifference imagine that by mere conversion into gas an immense quantity of energy can he added to fuel of other forms, forgetful of the law of nature, that. the conversion of any substance from one form to another involves a loss of effective energy, and therefore that if in certain cases more duty can be obtained out of the gas resulting from a given amount of coal than the coal itself will supply when used direct, the cause lies solely in the more efficient utilization of the fuel in its gaseous state. Nevertheless, new processes for making gas are constantly crowded upon our notice with claims of less cost for manufacture and delivery than natural gas, and often of far more energy for the product than is contained in the coal or oil from which it is made. I was recently asked to examine a new process of this kind. From an analysis shown me the calorific energy of the gas approximated 375 heat-units per cubic foot; on ascertaining the quantity of gas claimed to be made from a given amount of solid and liquid fuel, it appeared, that for every 325 heat-units contained in the latter 900 heat-units were alleged to he delivered into the gas, or nearly three times as much energy as the original fuel really held. The extravagant claim of some oil-gas advocates is still frequently heard, that by vaporizing oil with steam and then passing the mixture through a coil of hot iron pipe, an oil-water-gas containing 26,600 heat-units is formed from 1 pound of oil carrying originally 21,000 heat-units, while the only energy expended on the gas has been by the introduction of a -little steam and a little extraneous heat. Theoretically, 1 pound of oil converted into water-gas carries 26,600

Jan 1, 1890

By T. C. Davis

Nine organic derivatives of fluorine, silicon, boron, and aluminum were purified for thermodynamic studies using distillation, zone melting, and gas liquid chromatography, The unusual properties of these compounds required the development of special techniques for handling and purification. To determine purities of purified samples, new techniques for analyzing spectral data were developed.

Jan 1, 1965

By P. N. Anyalebechi

The effects of a cross-hatched grooved mold surface topography, casting speed, and superheat on the morphology of solidifying shells of aluminum alloy 3003 have been characterized by a series of immersion tests. The cross-hatched grooves were 0.232 mm deep with wavelength or spacing between 1 mm and 15 mm. The shells solidified at casting speed of less than 10 mm/s on the 1 mm spaced cross-hatched grooved mold surface were fairly uniform with little or no localized variations in thickness. However, the propensity for non-uniform shell growth morphology was exacerbated by an increase in casting speed, melt superheat, and the wavelength of the cross-hatched grooves. This is provisionally attributed to their effects on interfacial heat transfer and wetting of the mold surface by the molten metal.

Jan 1, 2008

Jan 1, 1970

By L. C. IlsLey

"There is an old saying that ""It is too late to lock the stable after the horse is stolen"". Is not this just what is being done by many mine operators today when it comes to buying safe electrical equipment for gaseous and dusty coal mines?The ""open type"" of electrical equipment or even the ""half safe"" type represents the unlocked stable. After the mine disaster, and after men have lost their lives, the lock is put on - that is, safer equipment is installed.For example, an open type of electric coal drill was used in a gaseous mine in West Virginia, This was the probable cause of the death of 27 men. A half safe type of electric coal-cutting machine was used in a gaseous mine in Pennsylvania. This was likely the cause of the death of 36 men. An unapproved, unsafe type of flame safety lamp was used in a gaseous and dusty mine in Utah. This was the all¬eged cause of the death of 171 men. All three disasters happened within the last six months, and seem to have been avoidable if proper equipment had been used.It is understood that more rigid requirements will be enforced in West Virginia. The committee of State mine inspectors made definite recommendation for im¬proving the conditions in the given mine in Pennsylvania. The Industrial Commission of Utah have already issued new orders which will remedy the use of unsafe lamps in that State.These acts and recommendation are all good and will help prevent accidents in those States in the future. Is it not a pity that such recommendations and order were not made a little earlier before the tell of life had been exacted? Is it not a pity that other States will not take these lessons to heart and safeguard their mines before and not after disasters take place?Electric current can cause accidents in five general ways as follows: (1) By shock to persons; (2) by igniting powder; (3) by igniting gas; (4) by igniting coal dust; and (5) by setting fire to inflammable material such as timber and coal. A great many accidents from these causes are preventable if proper care is taken. Most of the accidents caused by sparks and flashes from electrical apparatus would not take place if approved electrical equipment was used. By approved equipment, the writer means equipment that has been tested and formally approved by the Bureau of Mines. So far as known, up to the present time, no disasters have been caused by sparks or flashes from equipment having the Bureau's approval."

Jul 1, 1924

By C. A. Pryor

The aggregates industry is the largest minerals industry in the United States producing over 2.6 billion metric tons of crushed stone, sand and gravel annually. Approximately 5% of that production is fine material, passing a 75-micron mesh sieve. Of that amount, about 77% is not sold and represents one of the major industry issues. The material accumulates in stockpiles and settling ponds having an operational and economic impact on the site’s bottom line. Many factors cause this material to be produced: from blasting and processing techniques all the way to end use specifications.

Jan 1, 2002

By C. W. Morris

The continuous miner training system provides classroom materials training aids, and a continuous miner simulator to provide a short, intensive instruction and skills development program for training or retraining continuous miner operators. This project included refinement of training objectives, revision of training aids, improvements to the simulator, and evaluation of the entire system. This report describes the revised classroom materials and the validation of the training system.

Jan 1, 1982

By Peter J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 1991