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China's coal energy development, characteristics and relationships with atmospheric pollution are reported. Atmospheric pollution sources from coal combustion are analyzed. Some of the projects for clean coal combustion in the Shanghai area include use of industrial briquettes, investigation of coal combustion additives, and blending combustion of coal with industrial wastes. Coal is China's main energy source, and 80 percent of China's annual coal production is used in combustion devices. Coal-flue gases from the domestic stoves and industrial furnaces are the main atmospheric pollution source. China's atmospheric pollution is, in fact, the pollution of coal-flue gases. To 2000, in view of China's energy needs as a developing nation, the atmospheric pollution from coal combustion must receive our utmost attention.

Jan 1, 1994

By S. Tuylu, D. Adiguzel, U. G. Akkaya, A. Bascetin

"One of the main problems for storing of the tailings is acidity occurrence due to several factors such as existence of sulfuric minerals and also the pollution in seepage waters by mobilization of metal ions, which holds great risks in terms of environmental regulations. Because of these specified reasons, tailing materials to be used in a SPD formula should have comply with some specifications. Among these properties; oxygen content, temperature, matrix suction and pH are the most important parameters. In the study, the relationships between the parameters mentioned are investigated to reveal optimum paste design layout. The lowest amount of seepage water obtained from the paste layers in the pilot cabinet was found as 2150 ml from 3rd layer. As for the maximum seepage water and the average of the all 11 layers were found as 4909 ml from 6th layer and 3273 ml respectively. The reactions occurring according to the oxidation, as seen at seepage water of second and third layers, decreased the pH of system to the under of 7 value. Additionally, when the seepage water of first layer’s EC value is 2.93 mS/cm, the EC value of second layer is increased at 3.54 mS/cm. The other parameters are evaluated with the obtained results of the tests to determine the optimum storing conditions for SPD.INTRODUCTION Conventional waste disposal methods, although widely used, pose great environmental risks. One of the most important issues is acid mine drainage (AMD). Tailings of metallic mines contain heavy metals, aggressive chemicals and hazardous materials. In the presence of oxygen and water, an oxidation reaction can occur, causing a decrease in pH of the environment, and heavy metals that are present in the environment can dissolve easily. Subsequently, heavy metals can pollute underground water basins, creating a great amount of danger for the ecology and potable water resources. Another important risk associated with conventional waste disposal methods is accidents related to the waste dam. Higher volumes of water and tailings (usually 15% solids and 85% water by weight) are sent to waste dams, making it very difficult to control the stability of the dam under conditions such as static and dynamic loads (seismic activities, vibrations caused by blasting, etc.), flooding, and seepage. In case of an accident or failure, the spread of great amounts of mud containing hazardous chemicals and heavy metals can harm the environment of the dam site significantly (Bascetin et al., 2014). In the paste technology, depending on the type of ore, tailings used in the paste mixture can contain sulphide minerals (such as pyrite and pyrrhotite). These minerals are known to be reactive with water and oxygen to produce acidity (sulphuric acid)."

Jan 1, 2015

By A. J. Abraham, K. E. Seitz, J. D. Humphrey

Caterpillar has led the way for sound reduction in off highway trucks (OHT) used for mining. In 2000 Caterpillar introduced the 793CXQ sound reduction OHT (Figure 4) to meet local noise level demands in the Hunter Valley near Sydney, Australia. The sound level of the mining equipment in the Hunter Valley is being reduced to pre-serve the quality of life for the residents of the area. To meet the levels established required a major redesign of the 793C, as a result the sound power level was reduced by 9 dB (A), which is a less than 1/8the original sound level.

Jan 1, 2004

By Kadri Dagdelen, Thys B. Johnson, Salih Ramazan

Long-term production scheduling design is a very important part of mining because it determines the economic outcome of a project There have been many attempts to solve the optimum pit scheduling problem, but there has been no success in developing a scheduling method to give optimum results in maximizing net present value of a mining project. Open pit production scheduling problem can be formulated as a mathematical programming problem and solved using Mixed Integer Programming technique. However, it is not possible to solve the formulation within a reasonable time since the number of integer variables required for the mathematical model is too great to do that by today's available computer technology. There- fore, a methodology is required to combine, or aggregate, the mining blocks and to decrease the number of integer variables in scheduling without losing the optimality. Therefore, the fundamental tree concept was developed in this paper to combine the blocks. A fundamental tree is defined as any combination of blocks such that: 1. the blocks can be profitably mined, 2. the blocks obey the slope constraints and, 3. there is no subset of the chosen blocks that meets 1 and 2. A Linear Programming (LP) formulation is developed as a mathematical model to find a set of fundamental trees that exist for a deposit. Since the blocks are combined to form the fundamental trees, the number of variables required for the scheduling model is decreased significantly. This decrease in the number of variables makes it possible to mathematically formulate the multi-time period scheduling problem as a Mixed Integer Programming (MIP) model. A case study is performed on a multi-mineral copper deposit in Peru, South America. NPVs of annual after-tax cash flows generated based on the schedule provided by the "Fundamental Tree Algorithm" is compared with NPVs resulted from the schedules coming from three of the computer packages presently available to the mining industry. These are Mintec's M821V, Earth- work's NPV Scheduler, and Whittle's Milava open pit mine schedulers.

Jan 1, 2002

By Raymond E. Krauss

The McLaughlin Mine is a world class epithermal gold deposit located in the coastal thrust fault of Northern California, U.S.A. Homestake adopted a proactive strategy in the permitting of the Mine. Extensive environmental baseline studies were undertaken. Engineering and process alternatives were evaluated for environmental impact along with other factors. A unique pressure oxidation process was selected. Screening studies were conducted as a basis for the selection of waste rock and tailings disposal sites. Project engineering and permitting were fast tracked. Construction required eighteen months, and the first gold bar was poured in March of 1985, six years after the initial discovery. Project facilities are designed and operated so as to minimize environmental impacts. A comprehensive monitoring program demonstrates permit compliance. Reclamation of the site is ongoing throughout the Mine's twenty year life. Nonmined lands are managed to maximize wildlife habitat value.

Jan 1, 1990

Planning the primary development of a mineral deposit usually is done only once during the life of a mine. As a consequence, not optimizing the primary development of a mineral deposit can cause disadvantages over the whole life of a mine and can lead to higher costs. As a contribution to an improved primary development design procedure beyond the already existing work a study of the identification and quantification of the influence of parameters on primary development based on operational data from working mining operations has been completed. Based upon such a quantification of the influence of parameters a sequenced decision model was developed, that enables to develop an initial concept for the design of the accesses from the surface based upon a few critical parameters. Such a model will not replace detailed planning work within a feasibility study, but it is intended to reduce the amount of planning efforts at an early project stage through providing information what are most likely economic solutions, based on simple rules.

Jan 1, 1997

By C. J. Webb

Abandoned uranium mines in the southern Black Hills of South Dakota were sampled for uranium, radium, and rare earth elements during 1992 and 1993. Analyses of water samples from several shallow ponds in the mine pits showed pH values between 3 and 4 with uranium concentrations between 1600 and 2600 ppb. Rare earth elements and their respective isotopes were analyzed with an inductively coupled plasma mass spectrometer and were referenced to a shale normalization pattern. All samples showed an enrichment in the middle rare earth elements. Rare earth levels often were greater than 0.2 ppm. At one site, the concentrations of lanthanides were 150,000 times above background levels. While the southern Black Hills have long been known for rich uranium ore deposits, these analyses show that significant levels of rare earth elements also are present, indicating that the potential exist for future development.

Jan 1, 1995

By D. G. Kotlyar

Silver is an economically important component of many complex, massive sulfide ores. Current beneficiation for these ores is almost entirely by flotation. Silver recovery often is low, but little is known about the flotation behavior of the silver-bearing minerals. Floatability studies were conducted using silver-bearing tetrahedrite and lead-zinc ore. The effects of xanthate collector concentration, conditioning time, potentiostatic control of the mineral potential, and pH on mineral floatability were evaluated. The floatability of the silver-bearing minerals was shown to depend on collector concentration and mineral potential. The effect of controlling mineral potential during the flotation process is discussed.

Jan 1, 1994

By R. A. Speirer, T. C. Bettinger, L. P. Richardson

INTRODUCTION The Bureau of Mines (The Bureau) remote sensing researchers at the Denver (CO) Research Center, have been investigating computerized methods to detect and map surface linear features called "lineaments" for ground hazard assessment in mines. Many of these lineaments at the test mine site were found to correlate to subsurface geologic discontinuities such as faults, fractures, and joints that intersect coal seams at depth. These features adverse1 y affect the roof and rib integrity in underground mines, thus contributing to rock failures that may result in injuries to mine workers and loss of production. Advance knowledge of the existence of such hazardous geologic features can aid in mine planning and development. Lineaments may be observed in a variety of images of the earth's surface. Linear features that can be observed using Landsat mu1ti spectral scanner data (MSS) images range from regional (greater than 3 miles in length) to an intermediate length of from 1 to 3 miles. These images are recorded in discrete radiation bands in the green, red, and near-infrared portions of the el ectromaynetic spectrum. These data are acquired from the EROS Data Center of the U.S Geological Survey, Sioux Falls, SD, in digital format on magnetic tapes that are suitable for processing on certain minicomputers. Shorter lineaments length (less than 1 mile) can be observed in high- to low-a1titude aerial photography, radar, and infrared images with image scale ratios of 1:1,000,000 or less. These linear features can correlate to smaller dimensioned faults, and to fracture and joint sets at the local geologic scale. Other informational sources can help substantiate 1ineament analyses, such as well logs, mine naps, topographic data, and geophysical data acquired over the study site. These data must be in a digital format to process on the "DEC PDP 11/23 minicomputer system1". Data can be acquired in

Jan 1, 1986

By Jr. Wilkinson

In today's work environment a tremendous amount of data is required to provide the regulatory agencies justification to issue a mining permit. The demands for data, specifically environmental characterization data, grow and the mine plans must address the issues raised by the interpretation of that data. Computers and computer software can provide operators and consultants with the tools necessary to assimilate, digest and interpret these seemingly unmanageable data sets. This paper presents some examples of how Mincom's MineScape software can be applied to the task of developing coal mine permits in an electronic format.

Jan 1, 1996

By G. Davey

High speed stirred milling is a relatively new method of grinding in the metalliferous process industries. However it has been it has been in wide spread use in the industrial mineral field for over 30 years for various minerals. Many existing metallurgical operations are looking to maximize economic return from existing deposits, requiring new thinking and technologies. The operating experience of two existing copper operations will be covered to show the effect of the introduction of the Metso Stirred Media Detritor (SMD) a new type of high speed stirred mill. Both operations have derived significant metallurgical benefits from the introduction of this new technology. The benefits and process difficulties are covered and explained.

Jan 1, 2003

By K. L. Wiley

In-situ leaching, initiated in 1986 at San manual, was economically developed in 1989. The primary reason for this lag time between startup and viable production was the time required for technical development. The technical development pursued comprised detailed design, development, and implementation of in-situ well construction methods, formulation of suitable well pattern arrays, and the development of extensive hydrogeologic and geochemical knowledge of the mineral deposit. Since 1989, the in-situ leaching program has become a viable and cost effective method to extract copper from the supergene mineralized zone of the San Manuel deposit. The in-situ leaching methods that are currently utilized have been progressively expanded and continually developed and will became the cornerstone of copper production from the San Manuel oxide mineral deposit. This paper presents an overview of the supergene hydrogeology, current design techniques, drilling methods and well completion, pump determination and setting, solution management, and future plans for the increased extraction of copper by in-situ leaching methods at the San Manuel mine.

Jan 1, 1993

By S. S. Peng, Luo. Y.

In a shearer longwall mining operation, the longwall hits are responsible for breaking into and chipping the broken coal blocks away from the coal face. However, underground observations found that the bits being used were working under various degrees of wear. This wear can be reduced by using better-designed longwall bits and by properly selecting shearer operating parameters. A computer program was developed to simulate the performance of the longwall bits. The information required by the program are the shape of the bit head, the installation of the bits on the drum and the operation parameters. Through the simulations, the main factors affecting the bit-wearing process are identified. Suggestions are also made for improving the design of the longwall bits.

Jan 1, 1998

By Harlan L. Kebel

Gypsum, the dihydrate form of calcium sulfate, has a history of usefulness to man dating back several thousand years, and a worldwide industry has been built on the mining and processing of this versatile industrial mineral. However, anhydrite, the other prin¬cipal calcium sulfate mineral, has very limited use, so much so that separate statistics for it are not always kept, but are usually included with those for gypsum. Although often found in close association, the two minerals have important chemical differences in that anhydrite is the anhy¬drous form of calcium sulfate (CaSO4) whereas gypsum is the dihydrate (CaSo4.2H20). These two molecules of combined water result in significant differences in hardness, density, and solubility of the two minerals. Of most importance, however, is the difference in thermal properties wherein gypsum, upon the application of a modest amount of heat, can be converted to the hemihydrate of calcium sulfate (CaSO4 '21H20) or plaster of paris, an intermediate product upon which is based over 90% of the value of all calcium sulfate end products. Anhydrite, on the other hand, is inert at these temperatures and its uses have been limited to only those few cases where calcium sulfate in the anhydrous form may have an advan¬tage. The earliest known use of gypsum plaster dates back some 5000 years to the time of the Pharaohs of Egypt who had discovered that gypsum rock, when exposed to fire, broke down into a powder which, when mixed with water, would form a putty that could be plastered on a rough mud brick or stone wall to make a smooth finish. It was used down through the centuries in a limited way for ornamental purposes, but did not achieve wide acceptance because of the quick (25 to 30 min) setting or hardening time which made it difficult to use. The first real understanding of gypsum chemistry was developed in France about 1755, and the gradual growth of its present utilization dates from that time. In the United States, the first utilization of gypsum was to grind it to a fine material for use as a soil conditioner at about the time of the Revolutionary War, and the term land plaster for ground gypsum was coined and has remained in use. Another cementitious material-lime or calcium oxide-had become the usual plastering material, but by about 1870 a method for retarding the set of gypsum plaster was discovered; today it has almost completely replaced lime as a plastering material. In recent years, gypsum products sold in the United States have reached a total valuation of approximately $2 Gpy as illustrated in [Table 1].

Jan 1, 1994

By Richard M. Winar

In September of 1988, the United States Environmental Protection Agency (US EPA) published final regulations that effect owners and operators of underground storage tanks (USTs). These regulation include stringent technical requirements for owners and operators of USTs containing petroleum and certain hazardous substances. The technical requirements effect both new (those installed after December 1988) and existing USTs and include notification; performance and operating standards; release detection, reporting, investigation; release response and corrective action; and closure requirements for out-of-service USTs. The USEPA also published final regulations regarding financial responsibility requirements for owners or operators of petroleum USTs in October of 1988. These regulations require owners or operators of petroleum USTs to demonstrate financial responsibility for the costs of corrective action and compensating third parties for bodily injury or property damage caused by releases from petroleum USTs. Like thousands of other industries, the mining industry must become thoroughly familiar with these new regulations in order to properly manage their UST systems, ensure compliance, and understand other ramifications imposed by these regulations.

Jan 1, 1990

By Phillip R. Moyle

Voluminous deposits of commercial-grade phosphate occur in sedimentary strata in a 350,000 km2 (135,000 mi2) area of the middle Rocky Mountains of North America known as the Western Phosphate Field. The Permian marine strata that host the phosphate were deposited on the western margin of the North American craton and subsequently deformed, first by folding and thrust faulting of the Laramide orogeny, and then by Cenozoic Basin and Range block faulting. Carbonate fluorapatite is the primary phosphorus-bearing mineral. Organic matter is abundant in some strata, and both biogenic and non-biogenic pyrite are also present. Certain strata are enriched in several trace elements, especially in arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), molybdenum (Mo), selenium (Se), vanadium (V), uranium (U), and zinc (Zn). Phosphate has been mined from the Western Phosphate Field for nearly 100 years. Phosphate mining and processing constitutes the largest mineral industry of Idaho, producing more than $600 million in processed mineral value in 1997. Resource management agencies, phosphate producers, and others are concerned about the release of Se from phosphate mine wastes, especially at Maybe Canyon, and the potential effects that Se and other trace elements may have on the environment and on human health. U.S. Geological Survey (USGS) Mineral Resources Team scientists initiated a multidisciplinary study of the Permian Phosphoria Formation and related rocks in the south- eastern Idaho sector of the Western Phosphate Field in response to a request by the U.S. Bureau of Land Management (BLM). Studies to date reveal that Se is present in several phases, including native Se, and in an as yet unidentified form, possibly an organo-Se compound. Selenium is also present in pyrite and sphalerite. Selenium concentrations range from 1.2 to greater than 1,000 parts per million (ppm) in samples collected from exposures of the Meade Peak Phosphatic Shale Member of the Phosphoria Formation (Meade Peake) at Enoch Valley. The results suggest that Se concentrations vary spatially across strata and with depth, perhaps comparable to spatial variations of phosphate and organic carbon concentrations throughout the Western Phosphate Field demonstrated in previous studies. Some Se-enriched strata may be of adequate dimension to allow selective extraction during mining. Such units could be handled separately from the main ore process or waste streams and isolated in order to reduce the potential for release of Se to the environment

Jan 1, 2001

By V. Steinbach

Non-renewable mineral raw materials are grouped into three categories to investigate ways leading to sustainable use of natural resources: 1.) metallic resources, 2.) non-metallic resources with the exception of the fertilizer minerals, and 3) the fertilizer minerals for the nutrients nitrogen (N), potassium (K), and phosphorous (P). With the exception of minerals in Group 3 which are essential for plant growth, mankind does not need raw materials as such, only the intrinsic property of a material that fulfils a useful function. This is especially true for non-metallic materials. Metallic resources have the best chance to become renewable if one makes optimal use of the resources of the man-made technosphere. For the fertilizer elements K and N there does not exist a problem, because sea water or air respectively provide an inexhaustible source for them. This does not apply to P however. So P is serving as one of our apposite case studies for solving sustainability challenges. For all the challenges along the road from a non-sustainable to a sustainable resource economy technology can be envisioned to come to the rescue provided conditions that are considered to be essential for sustainable use for all natural resources-- affordable renewable energy and human ingenuity to find new solutions for functions, to optimize processes and to minimize losses-- are satisfied.

Jan 1, 2011

By A. D. Davis, C. J. Webb

Brohm Mining Company's Gilt Edge Mine in the northern Black Hills was a surface heap-leach operation that was active from the 1980s until 1999. Financing problems and acid drainage concerns at the mine were reported in the late 1990s. In February of 1999 the Governor of South Dakota announced plans to request the U.S. Environmental Protection Agency to help clean up acidic water at the mine and reclaim the site. In July 1999 the parent company of Brohm, Dakota Mining, filed for bankruptcy in Canada. Because of the bankruptcy and environmental problems, the State of South Dakota intervened and began water treatment. The mine was declared a Superfund site in 2000. Hydrologic issues include the potential for acidic drainage from the site. The mine is at the headwaters of Strawberry Creek, which drains into Bear Butte Creek. About four miles downstream, Bear Butte Creek loses its discharge to swallow holes in the karstic Madison Limestone aquifer, a regionally extensive and valuable ground-water reservoir. Other concerns at the site include treatment of acidic water in mine pits and a waste rock dump.

Jan 1, 2002

By F. Montgomery Lyon

Pyritic sulfur in coal occurs as discrete mineral particles, and its liberation and physical rejection is the primary target for coal desulfurization. An acceptable solution to the pyrite removal problem from fine coal is not found in the standard methods of coal cleaning such as jigging, heavy-medium separation, tabling, and hydro-cycloning. Although fine coal is an ideal size for froth flotation, this method, as currently practiced is also unsuitable as the fine pyrite usually floats with the coal. One possible solution to this problem may be the froth flotation of pyrite from coal. This reverse flotation scheme would have the major advantage of removing both free pyrite and locked pyrite-coal combinations. With this possibility in mind, we have, as a first step, compared the flotation and adsorption. characteristics of an ore-pyrite and coal-pyrite with potassium-ethyl-xanthate as a collector 1 Related Research. The action of ethyl-xanthate on coal has been studied 2 by Horsley. He measured the contact angles of coal in distilled water and in the presence of purified ethyl-xanthate. The results indicated that the xanthate was not adsorbed by the coal. Additional contact angle data were obtained to determine the effects of cupric, ferric, and ferrous salts on the system. Then either the ferric or cupric salts were in, solution with the xanthate, there was an increase in the natural contact angles of the coal. This indicated that these heavy metal ions activated the flotation of the coal with xanthate. However, ferrous iron did not act as an activator. Horsley stated that the most attractive explanation was that the xanthate is oxidized to dixanthogen in the presence of the ferric and cupric ions.

Jan 1, 1971

By Gary L. Simmons

Noranda's Grey Eagle Mine and Mill, located in the Siskiyou Mountains of Northern California, began shakedown operations in the late fall and early winter of 1982. This paper describes some of the unique features in mining, milling and water treatment operation at Grey Eagle. In addition, major start-up problems in the mill and water treatment plant are discussed along with measures taken to correct these problems.

Jan 1, 1984