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By Sam McNary

The U.S. Bureau of Mines used the East Fork Pine Creek watershed to conduct a pilot study for an inactive and abandoned mine lands inventory, during which techniques and methodologies would be developed for subsequent inventories. A total of 177 waste dump samples, 191 mill tailings samples, and 36 stream sediment samples were collected. Water samples were collected from 18 sample sites during five sampling events. Waste dump, tailings, and stream sediment samples were analyzed for antimony, arsenic, cadmium, copper, iron, lead, mercury, and zinc. Results indicate a multidisciplinary approach is necessary: disciplines should include geology, geostatistis, geochemistry, geophysics, biology, hydrology, and remote sensing; small prospects do not generally contribute to watershed contamination, major mine and mill sites may contribute metal enriched sediment of metal enriched water; speciation studies and bioavailability studies are important.

Jan 1, 1995

By J. L. Shultz

Mass spectrometric analyses were obtained for naphthalene and anthracene oils, heavy creosote, and three fractions of a pitch. The average molecular weight, aromaticity, and mean structural unit were determined for each fraction. The investigation of these fractions of coal tar has resulted in semiquantitative data for 38 structural types and carbon number distribution data for their alkyl derivatives. The molecular weights of 10 of these structural types indicate ring systems not previously reported in products from high-temperature carbonization of coal. Two of these structures are poly-nuclear aromatic hydrocarbons, two are oxygen-containing compounds, one contains sulfur, and five are nitrogen-containing compounds.

Jan 1, 1967

By AIME AIME

SECTION DELEGATES were given an opportunity to see how the machinery of Institute administration functions, on Tuesday evening, Feb. 16, when they were the' guests at the regular monthly meeting of the Directors. Of the new board of 25 members, 19 were present at the meeting, including directors from Seattle, Los Angeles, Wyoming, Oklahoma, Chicago and Pitts-burgh, the new junior past-president from Jerome, Ariz., and the new president from .Washington, D. C. The complete list of the 72 in attendance at the dinner,: held in the main dining room of the Engineers' Club, which pre-ceded the general session of the Directors'. meeting, follows:

Jan 1, 1932

By Wesley Hermanson

Canopies were designed, fabricated, installed, and demonstrated for mining machinery in 3-foot coal seams. A Wilcox PJ20 Auger miner, a Wilcox Bolter, a bee Norse 245 miner, and an Elkhorn Scoop AR3 modified to AR4 were fitted with canopies. The Wilcox Bolter canopy was hydraulically adjustable in height; the rest were manually pin adjustable. The machine operators' comments were adverse in each case. Restriction of visibility and body constriction into unaccustowed and tiring attitude were major objections, causing increased hazards and fatigue. Recommendations are made that roll bar protection be furnished in place of canopies for 3-foot seams to provide partial protection by deflecting and supporting roof falls but not covering the head of the operator. In this way, the effect on visibility would be minimized and fatigue from body restriction would not be increased.

Jan 1, 1976

By William R. Beloff, Franklin M. Grynkewicz, Puza

Construction of the MBTA Red Line Extension through Somerville, MA, called for driving twin tube tunnels through a zone of approximately 83m (273 ft) with mixed face conditions. While the majority of the tunnels were driven through competent hard rock using drill and blast techniques, the mixed face zone was advanced using floating crown bars for primary support. The overburden consisted of medium clay, underlain by water bearing glacial till, over a sloping bedrock surface. Due to the unusual nature of the construction techniques, a program was undertaken by the Contractor to monitor ground movement and stresses in the temporary steel supports. This paper presents a description of the instrumentation employed, as well as the measured ground movements and support stresses. Additionally, the tunneling techniques are briefly presented and commented upon. PROJECT DESCRIPTION The Davis Square to Porter Square Tunnel Contract is part of the Massachusetts Bay Transportation Authorities (MBTA) Red Line Extension from Harvard Square in Cambridge to the Alewife Brook Parkway via Somerville. The 5.1km (17,000 ft) Red Line Extension consists of four major new stations, three of which will be interlinked via tunnel construction, and the remaining station will be the last link of an open cut portion, and a terminal point for this phase of the extension. This 866m (2,790 ft) portion began at Porter Square in Cambridge and rose at a 4% slope through Somerville, terminating at the new Davis Square Station. Twin tube tunnels were constructed through 763m (2,517 ft) of rock and 83m (273 ft) of mixed face conditions at the Davis Square end. Figure 1 presents a plan view of the entire contract.

Jan 1, 1981

By E. S. Bardwell

DURING the period extending from May, 1922, to September, 1923, the copper-refining furnaces of the Great Falls Reduction Department of the Anaconda Copper Mining Co. at Great Falls, Mont., were operated exclusively with pulverized coal as fuel. The installation was made first as an experiment. It proved successful from the start and was abandoned solely because fuel oil from the Sunburst field became available at a price sufficiently low to make its use desirable from an economic standpoint. The equipment required for pulverized coal has, however, been kept intact and is available for immediate use should the oil supply fail. Inasmuch as pulverized coal had been used on two large reverberatory smelting furnaces and was, at the time we were considering its application to the copper-refining furnaces, being used on the Wedge furnaces roasting zinc concentrate for the electrolytic zinc plant, we were equipped with a coal-pulverizing plant of ample capacity to supply pulverized coal for the furnace refinery. The only problem was to devise suitable means for transporting pulverized coal from the pulverizer plant, located in the smelter building, to the refinery about 1000 ft. distant and about 150 ft. above the level of the pulverizer plant. When studying this installation, it should be borne in mind that the layout represents an adaptation suited to the existing conditions at this particular plant. The installation was entirely satisfactory and uniformly dependable but might be modified to advantage from an operating point of view if an entirely new installation were being planned.

Jan 9, 1925

By Kelly E. G

New Zealand suffers the disadvantage of widely scattered ore bodies, none of which is large enough to economically support its own smelter. This leads to the concept of a centrally located smelter which must be flexible enough to cope with var

Jan 1, 1980

By I. Gombköto

Mining and mineral processing operations are usually generating huge amount of tailings. These tailings often gives lots of maintenance work in order to protect environmental resources from heavy metals slowly leaching out of tailing are due to Acid Rock Drainage (ARD) process. Handling leakage could be active or passive such as using of Permeable Reactive Barriers (PRB). PRB?s are used worldwide treating underground contaminations, using different type of matrix materials. All generally used matrix material has its advantages and disadvantages such as selectivity, sensitivity of precipitation generation or not satisfying hydraulic conductivity. Nowadays cheap and effective matrix material which is ignorant to pore plugging caused by precipitation within the PRB could be one solution to the demands of the industry. The authors have been carried out an investigation at University of Miskolc on lignite as high humid acid containing material for determining the ability of heavy metal adsorption and pore plugging resistance. Moreover, using hydraulic and chemical simulation methods, complete PRB dimensioning protocol based on new lignite matrix had been introduced. Within the frame of this paper the results are going to be discussed.

Sep 1, 2012

By Sumner M. Anderson

THE importance of the mineral industries of the Latin American area in 1964 may be evaluated in respect to a number of points of reference, a few of which are measurable and appropriate for examination. With regard to the region's contribution to total world production, it accounted for total 1964 world output of natural nitrates (from Chile), and about 97 percent of the optical and electrical grades of quartz crystal (from Brazil). The region supplied over 20 percent of world output of 7 other mineral commodities and accounted for 4 percent or more of world output of 19 other mineral products. Among major commodities, the area, occupying 15 percent of the earth's land surface, supplied within 3 percent of that proportion of the world's output of copper, lead, tin, zinc, barite, and crude petroleum. Incomplete compilation of production data, particularly that of nonmetallic minerals, precludes production estimates on some items for the area ass whole, and therefore the importance of Latin America as a world producer of some additional commodities may not be clearly assessed. For example, most of the countries of the area collect only incomplete data or no data at all on the production of clays and other ceramic materials, sand and gravel, dimension and crushed stone, lime, ornamental and precious stones, perlite, vermiculite, carbon black, coal tar products, and petrochemicals. In the case of many countries of the area, the value of production of one or more of these commodities greatly exceeded that of other mineral industry products that are carefully reported.

Jan 1, 1966

By Oliver Bowles

The term "stone" in its broader sense includes not only the well-known limestone, marble, granite, sandstone, and slate but also precious and semi precious stones and many minerals and rocks not included in the principal groups. Stones have long been used for structural and ornamental purposes. To be so used, they must be cut to various shapes and sizes, and some must be polished to bring out their inherent attractiveness.

Jan 1, 1958

By R. V. Ramani, V. T. Burgos, J. A. McClay

Summary Cost models have, long been confined to the accumulation and analysis of static-data.. While historical and time study data are valuable for control of existing operations, for new systems and equipment, and for projections, they need to be adjusted or modified. The availability of computer-oriented systems simulators provide yet another method for costing these systems and equipment. This investigation has introduced a concept whereby continuous, variable data can be assimilated and analyzed through the combination of an economic analysis model, which includes a direct costing capability, with a systems simulator. This tandem operation permits increased flexibility and greater atten¬tion to detail in the evaluation of mining systems. The direct costing process is carried throughout the majority of the model operations. Labor and capital costs may be computed directly, even in the absence of the systems simulator, while operating costs re¬quire input parameters, at present, from the subsystems of the Master Design Simulator. Since the costs computed are based on the perfor¬mance of each individual machine unit, the model may be used to evaluate equipment compatibility, system interaction at the mining face, and the effect of system elements on total mining costs. Additional applications of the cost model include the following: 1. Complete mining systems may be evaluated, over their economic life, to determine the feasibility of a profitable operation. 2. Costs associated with mining various segments of the coal deposit may be computed as a guide to planning the mine layout and scheduling the sequence of operations or acquisition of new

Jan 1, 1975

The investigations reported herein comprise preliminary studies to evaluate large scale mining systems adaptable to the thicker oil shale deposits in the deeper central portion of the Piceance Creek Basin. The studies include an evaluation of the geology, hydrology and resources of the Basin., evaluation of a potential prototype mine site, synthesis of rock mechanics data on Green River Formation oil shale, selection and preliminary design and cost evaluation of six potential mining systems and a ranking analysis to aid in selecting the most promising system. Results of the ranking analysis indicate the following four systems to be most promising for large scale underground oil shale mining: - Chamber and pillar (using spent shale backfill) - Sublevel stoping with spent shale backfill - Sublevel stoping with full subsidence - Block caving with LHD's Recommendations for phase II are to investigate the above systems in greater detail, refine present cost data, and perform economic evaluations of oil shale mining using these systems.

Jan 1, 1975

By John Haviland, Richard E. Danell

"BHP Australia Coat Pty Ltd (BHPAC) operates seven large open pit coal mines in the Bowen Basin ofCentral Queensland, Australia. These mines have operated for periods ranging from 16 to 37 years. All of these mines have dipping seams to varying degrees and are facing increasing overburden removal in an effort to maintain production. To ensure the economic viability of the operations, this increased level of overburden removal must ah.0 be conducted at lower unit costs."

Jan 1, 1995

By James L. Hendrix

A study was made of the United States Bureau of Mines' chlorine-oxygen leaching process for complex sulfide concentrates. The investigation sought to determine the kinetic order and IT mechanisms involved in the reactions betweens sphalerite, and galena with chlorine. The influence of copper on the extraction rates was also studied. It has been shown the rates of reaction of chlorine in aqueous solutions with sphalerite and galena are both zero order at 373K with the rate limiting step being the chemical reaction. Addition of cupric chloride increased the extractions of both lead and zinc.

Jan 1, 1980

By R. L. Guerguerian

Critical fasteners are described as they apply to the specification, manufacture, and assembly on large grinding mill bolted joints. The importance of adequate design methods, related joint diagrams and pivot analyses, and special emphasis on the quality of manufacturing and the tightening procedures in the field, are discussed; all in an effort to ensure high availability plant operation.

Jan 1, 2001

Stope width was controlled around 3.5 feet for the narrow high grade vein system at Hollister Gold Mine. Without top access, backfill material was pumped from bottom access up into stope through a series of pipes after ore had been slushed out in each mining cycle. Backfill material was changed from one layer of low strength concrete plus one layer of high strength concrete cap to one layer of low strength cellular concrete plus one layer of high strength concrete cap. Backfill cost was cut down to 30 percent during this process. To reduce the steel concrete pipe set up and tear down time which was about 2 to 3 shifts in each mining cycle, steel pipes were left in man-way between mining cycles. Cellular concrete was firstly introduced into backfilling stopes at Hollister mine in Nevada Mining. This process including concrete pump selection, pumping pipe selection, material mixing, material mechanics and quality control were fully covered in this paper. CUT AND FILL MINING CYCLE The most flexible mining method, cut and fill (Figure 1), was used to mine the high grade, narrow steep vein system on this Northern Nevada property which is located eighty miles north east of Winnemucca. Without top access, stopes were accessed through two man-ways on each end, in which people travel ladders and material transport slides were set up (Figure 2). Each mining cycle was called a cut, from 6 to 8 feet high. Overhand sequence was used. Mining cycle started with drill and blast the middle portion of the stope, then expanded towards both ends. Broken ore was slushed into mill hole located at middle of the stope and then mucked out through bottom access into main haulage. Stope length was about 300 feet, which was restricted by slushing distance. Timber man-ways and mill hole would be raised and established for backfill and ready for the next mining cycle.

Jan 1, 2011

The HB 2500 hydraulic breaker attachment from Atlas Copco Construction Tools features Krupp percussion technology and a service weight of 2,500 kg (5,512 lbs). This makes it ideal for demolition, tunneling, trenching, foundation work, rock mining and secondary breaking. Suitable for carriers in the 29-to 43-t (32-to 47-st) weight class, the HB 2500 accepts maximum hydraulic flow of 219 L/min (58 gpm) at 18 MPa (2,610 psi) of pressure, and delivers an impact rate of up to 550 blows per minute. The HB 2500 features PowerAdapt, a new system that automatically shuts down the breaker in the event that it receives excessive oil pressure from the carrier.

Jan 1, 2006

By Peter Amelunxen, Craig Lockhart

Significant effort was made in 2003 and 2004 to upgrade the existing instrumentation and process control infrastructure at the Phelps Dodge Bagdad copper concentrator. Specifically, • cameras were installed on the feed belt for online image analysis data, • ultrasonic level sensors were installed for froth height and sump level control, • a trial froth image system was installed on one of the rougher rows, and • a new expert system to tie everything together was integrated and tuned in-house. Control philosophy, observations, opinions, and general tips and tricks are discussed with the hope of assisting other plant personnel and expert system integrators.

Jan 1, 2005

By Maria I. De Rosa

Table 28 and figure 10 show the number of fires and fire injuries for coal preparation plants by state during 1990-1999. Table 28 also shows the risk rates, employees' working hours, and lost workdays by state. For coal preparation plants, 91 fires occurred in 1 1 states during 1990- 1999. Twenty-three of those fires caused 25 injuries (the yearly average was 9.1 fires and 2.5 injuries). Ten fires and eight injuries involved contractors. The Ewhr value was 24 1 x 10' hr (Irr = 0.02 l), and the LWD value was 198. Pennsylvania had the most fires (24 fires and 4 injuries), whereas West Virginia (22 fires and 7 injuries) and Kentucky (22 fires and 7 injuries) had the most fire injuries. Among these states, Kentucky had the highest injury risk rate value (Irr = 0.025). Table 29, partly illustrated in figure 11, shows the number of fires, fire injuries, risk rates, employees' working hours, and lost workdays by time period. The number of fires decreased during most of the periods (an increase is seen only during the last period). The number of fire injuries show a decrease followed by an increase during the periods, accompanied by a decline in employees' working hours throughout the periods. The Irr values follow patterns similar to those shown by the injury values (see table 29 and figure 11). Tables 30-35 show the number of fires by ignition source, method of detection and suppression, equipment involved, location, and burning material by time period. Figure 12 shows the major variables during 1990-1999. Table 36 shows the fire injuries per number of fires causing injuries and total fires by year, ignition source, equipment involved, and location.

Jan 1, 2004

By Jon K. Ahlness

The Bureau of Mines, in cooperation with the Institute of Mineral Research of Michigan Technological University, and the Upper Great Lakes Regional Commission, conducted an investigation of electronic sorting of native copper ore from Upper Michigan. This report is based on research by the Institute of Mineral Research under contract to the Bureau. The test program evaluated the use of belt and rotary sorters on various size and grade fractions of ore. Both plant-scale sorting and lab sorting tests were run. The plant sorting objectives were to determine the sortability of different ores and the efficiency of the electronic ore sorters. High-and low-grade ores from both conglomerate and amygdaloid types were separated into four size fractions. The two larger sizes were sorted on belt sorters and the two smaller ones on rotary sorters. Copper recoveries ranged from 20.0 pct from a feed grade of 0.40 pct to 80.3 pct from a feed grade of 1.08 pct. Lab sorting tests of conglomerate ore were run to determine the efficiency of a belt sorter equipped with a second sensing coil located above the belt and to determine the sorting characteristics of larger ore size fractions than those used in the plant sorting. Copper recoveries from the combined feed sizes ranged from 47.0 pct from a feed grade of 0.13 pct to 96.8 pct from a feed grade of 4.87 pct. For all the ore types except one, it was found that the copper recovery increased with the feed size.

Jan 1, 1980