Search Documents

By D. Randall Crooke, Ron R. Jorgenson

Many coal combustion products (CCPs) have historically been unsuitable for placement as mine backfill because of their physical and geochemical properties and/or regulatory status. However, innovations in paste production and transport of CCPs utilizing the high, fine particle contents of these fine-grained waste materials and their water retention colloidal properties produce a non-segregating, self-cementing material that may be environmentally suitable for placement as mine backfill. Both industry and the regulatory agencies are enthused by the possible cost reductions, both in design and construction of disposal sites, and the reduced environmental impacts of CCP realized by implementation of this new use/disposal technology.

Jan 1, 2001

By D. J. Beeby

California's Surface Mining and Reclamation Act (SMARA) was passed in 1975 to identify and protect mineral resources in areas of high land use conflict and ensure reclamation of mined lands. Under SMARA, aggregate resource availability is quantified and compared to forecasted demand in specific market regions. Fifteen regions studied thus far cover 51,800 km2 (20,000 sq miles) and contain 45 Gt (50 billion st) of high-quality aggregate resources that have been legally designated as "regionally significant," providing a measure of protection previously unavailable. SMARA reports and state testimony at local hearings have supplied objective information and helped reduce conflict in mine permitting decisions.

Jan 1, 1987

By James O. Mawyer

Fuel is a major .cost for power generating utilities. Virginia Power is completing one of the nation's largest coal reconversion programs. As a result, 10 million tons of coal will now be used at six generating stations. Four of these stations are located on naviagable waterways. They consume over half of Virginia Power's coal. Historically, railroads have exclusively served these plants. In an effort to substantially reduce fuel cost, Virginia Power has reexamined transportation logistics and is proceeding with barge delivery. A phased approach was used by Virginia Power for the transportation program. Plant requirements were first identified. Coal sourcing issues were then examined. The concept of intermodal transportation was investigated. The bottom line cost savings was used as the criteria for continuing the project. The results thus far have been gratifying. Virginia Power has begun to implement barge transportation.

Jan 1, 1986

By J. C. Heter

Industrial Mineral Fillers, LLC. is in the initial stages of mining and processing Anorthosite (CASPAR TM) at its CASPAR mine located in Soledad Canyon, Los Angeles County, California The CASPAR is being mined from the Precambrian San Gabriel Anorthosite Complex of the western San Gabriel Mountains. Preliminary results suggest that CASPAR is a desirable alternative to silica sand used in construction applications, such as, stucco, grout, abrasives, and other uses including filtration and golf course recreation sands. With the use of standard ore dressing techniques, CASPAR is suitable for use as a filler in paint, plastics and rubber. Environmentally, CASPAR has advantages over silica sand, in that, there is no detectable Free Silca.

Jan 1, 1997

The Putnam Coal Mine, at design capacity, will be the third largest underground bituminous coal mine in the world and will feature the world's longest single flight belt conveyor. Construction is now in process; initial mining will commence in early 1969 and design capacity will be reached in 1971. I'm Jerry Workman, Assistant Mining Manager for the Coal Group of the Mining and Metals Division of Union Carbide Corporation, and I am acting as Project Manager for installation and start-up of the Putnam Mine. The Putnam Coal Mine reserves are located in south-central West Virginia and contain approximately 27,000 acres of prime Pittsburgh No. 8 coal; reserves are sufficient to support a 3.5 MM tons per year operation for over 30 years. The mine portal area is located some six miles inland from the Kanawha River. The river loading facility is located approximately 156 miles by way of river from the market.

Jan 1, 1968

By Patrick Shea

Old mine workings are found throughout the Western United Sates on lands administered by the U.S. Bureau of Land Management, U.S. Forest Service and private lands. Some of these mine workings date back to the late 1800s. There may be as many as 100,000 sites on lands administered by the National Park Service, U.S. Forest Service and Bureau of Land Management. The U.S. Department of the Interior has worked with the U.S. Geological Survey, the U.S. Forest Service, the U.S. Environmental Protection Agency, and western state governments to identify and prioritize these sites on Bureau of Land Management, National Park Service and U.S. Forest Service administered lands. This presentation will discuss the accomplishments we have made to date to clean up inactive and abandoned mine sites, focusing primarily on lands administered by the Bureau of Land Management.

Jan 1, 2000

By Libby R. Ricafort, Nonato S. Retardo, Jose B. Anievas

This paper shows the metallurgical test results that led to the design of the heap leach facilities of Philex Mining Corporation. The design incorporates a water management model as process solution circulation is excessive with high rainfall intensity in the area. This poses problems in the operations requiring stringent controls than would be necessary in a less severe environment. The corporate perspective embraces on environmentally-sound mineral development. A budget is always provided to environmental management making certain that no industrial development is moved forward at the expense of the environment.

Jan 1, 1996

By Y. J. Wang

The Hardy Cross iterative method is the most popular technique for solving a ventilation network problem with natural air splitting. This method traditionally solves each mesh equation by an approximation during each iteration. Thus, it is interesting from both a theoretical and a computational viewpoint to be able to solve for an exact solution to the mesh equation. Presented in this paper is an algorithm for computing the exact solution to the mesh equation with a variable fan pressure. The algorithm uses signum functions for air quantities to generate an alternative mesh equation in the form of a quadratic equation that has two solutions defined by the well-known quadratic formula. The condition that the derivatives of the alternative and the original equations must be the same provides a basis for the correct choice between the solutions.

Jan 1, 1998

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

By Terry A. Rightnour

Multiple seam mining is predominant throughout the central Pennsylvania Appalachian coal fields. Wide ranges in individual seam thickness, coal quality, and overburden characteristics are common throughout the region. On typical mining permits, ranging from 404 x 103 to 2023 x 103 m2 (100 to 500 acres), often as many as eight seams are concurrently mined, with each interburden requiring unique economic and environmental consideration in the mine plan. Specifically, this paper presents several planning tools and operational guidelines developed in response to current regulations for the special handling of potentially acid-forming materials as they are related to development and operation of multiple seam mines.

Jan 1, 1984

By N. P. Reddy

This paper describes an experimental setup for multiple-fan ventilation systems at the ventilation laboratory of the WVU Department of Mining Engineering. Housed in a 30 ft by 70 ft room, the experimental setup consists of three 18 in. variable-speed axial-flow fans, the 18 in. diameter fiberglass tubing and fittings for arranging networks, and the pitot tube measuring and data acquisition system. The fiberglass tubing and fans can be organized into the non-planner network of two fans or three-fans. It is mainly designed for studying the characteristic curves, operating points, and fan stall for the multiple-fan ventilation system.

Jan 1, 1992

he leaching behavior of palladium in ammoniacal solutions has been investigated by using the rotating disk technique in an autoclave. The study included the effect of rotating speed, temperature, oxygen pressure, composition of ammoniacal solutions, and catalyst on the overall leaching rate. The dissolution of palladium in ammoniacal solutions was discussed in view of the thermodynamics and a kinetic model. Even though the potential-pH diagram suggests that palladium metal can dissolve in ammoniacal solutions at room temperature, it was found that the dissolution was too slow at temperatures below 100°C but was significantly improved at higher temperatures. It was also found that the rotating speed of palladium disk had no effect on the leaching rate. The apparent activation energy was found to be 69.7 kJ/mole. Based on the results obtained, it is concluded that the dissolution of palladium is controlled by chemical reaction.

Jan 1, 1997

By R. M. Damodaran

The flotation performance of Florida phosphate rock was evaluated in terms of the mixing behavior of reagents with particulates during anionic conditioning of phosphate slurries. The various conditioning variables that influence mixing, namely, solids loading, agitation speed and the conditioning time were investigated to determine their effect on reagent coating on the particles. The phosphate recovery was used to monitor the conditioning efficiency. The mixing characteristics of the phosphate feed were evaluated in terms of the ratio of the mixing power P, to the minimum power Pm' required to keep the slurry in suspension. It was found that mixing conditions govern the conditioning time required to obtain high recovery. Reagentization was slower at lower P /P m ratios. At higher P /P m ratios, the flotation recovery was optimized and the agitation speed was found to have no significant effect on it. Optimum mixing conditions were obtained for a 74 wt% slurry at an agitation speed of 450 (47 rad/s) rpm. Under the optimum conditions of mixing, recovery was improved at low collector dosages and short conditioning times.

Jan 1, 1995

By Ralph L. Merklin

One of the most commonly employed set of calculations in mill design and research is the material balance, known in wet beneficiation plants, as an Ore and Water Balance. For mill designers, the balance is one of the principal requirements in determining the proper size of launders, pipelines, process equipment, etc. In process development, one of the major goals is the establishment of an optimum balance. The usual procedure for calculating a material balance involves a manual technique utilizing reference tables, pre -obtained data, and a slide rule or desk calculator. With these, the engineer must perform a series of calculations which are repetitious in nature and time consuming. Figure I is the flowsheet of the grinding and flotation circuits for a copper concentrator. The initial ore and water balance was calculated manually and required approximately 24 manhours. Later, a number of changes were made in the balance, each of which required an average of 8 manhours.

Jan 1, 1967

By James E. Palmer

Geologic constraints on mining and recoverability include the following: coal seams too thin or thick for conventional mining methods; coal seams with insufficient stratigraphic separation; unstable roof or floor strata; discontinuous or lenticular seams; coal seams that have high dips or are intensely faulted; water problems due to proximity of aquifers; and coal quality problems such as excessive sulfur, ash, chlorine, sodium, etc. The demonstrated reserve base for western coal of 220 billion tons is considered misleading as it does not adequately incorporate the above parameters in estimating procedures. Current reserve base estimating procedures involve an abstraction of data from generalized resource estimates. The authors believe the reserve base should be determined independently beginning with well-known deposits, with all mining and recoverability constraints fully incorporated.

Jan 1, 1981

By Y. Luo

Although considerable progress has been made in the last decade in predicting surface subsidence over longwall panels, a number of important issues deserve further studies in order to improve the techniques and accuracy of subsidence predictions. Some of the problems are: (1) subsidence over the chain pillars between mined longwall panels; (2) subsidence development process after face stop due to either a vacation or the completion of a longwall panel; and (3) subsidence initiation and development process over the setup entry area in the initial stage of mining a longwall panel. In this paper, the measured data related to the targeted problems are presented, the data analysis techniques are briefly introduced, and some of the prediction methods developed based on the collected data are proposed. The proposed methods can be used as supplemental tools for the existing subsidence prediction models to improve their prediction accuracy.

Jan 1, 1991

By Harold V. Fairbanks

This investigation included a study of three different methods for the acoustic drying of ultrafine coals. Ultrafine coal being defined as coal which passes through a 100 mesh sieve. The first method employed stationary drying of small coal samples in sound fields having frequencies of 12,000 cps and 20,000 cps. Sound intensities up to 150 db were used. The second method employed the use of rotary drying kilns. The effect of such variables as temperature, sound intensity, coal feed rate, air flow rate, and initial moisture content were studied. The third method employed the use of a multi-tiered, vibrating screen dryer. The effect of initial moisture content and residence time were studied.

Jan 1, 1970

By James K. Gowans

The Red Dog Operation is located in northwestern Alaska at Latitude 68°, 100 miles north of the Arctic Circle and 50 miles inland from the Chukchi Sea. The orebody was acquired by the NANA Regional Corporation, (an Alaska Native Corporation established by the Alaska Native Claims Settlement Act of 1971), in 1980 in their land selection. In 1982 Cominco American and the NANA Corporation signed a development agreement and Cominco Alaska Inc., a wholly owned subsidiary of Cominco American, was formed to manage the Red Dog Project. An extensive exploration program in 1980 -1982 outlined a mineral inventory of 85 million tons, at a grade of 5.2% Pb, 17.1 % Zn, and 2.4 oz/ton Ag, which makes the Red Dog the second largest deposit ever discovered. Broken Hill, in Australia, is the only zinc orebody which was originally larger than Red Dog. The design of the facilities is to process 2.1 million tons of ore annually, which will produce 560,000 tons of zinc concentrate, 100,000 tons of lead concentrate and 50,000 tons of bulk lead/zinc concentrate.

Jan 1, 1991

By J. D. Vincent

The Henderson mine site is located at Red Mountain on the eastern slope of the Rocky Mountains, approximately 50 miles west of Denver, Colorado. The mill site is on the west slope of the Rockies and mine and mill will be connected by an underground railroad. All designs were for a 30,000 ton per day molybdenite processing plant with provisions for future expansion up to 50,000 ton per day if required. This plan did not just happen, but slowly evolved over the course of about three and one-half years. Many plants cannot afford such a delay, but the Henderson project will take about 10 years from the time it was first discovered until production starts, and these 3 !1 years were well spent in determining the best possible plant site and flowsheet. This paper describes some of the problems and the decisions made in arriving at the final location and flowsheet. The paper does not go into the specific details of how protection of the environment went hand-in-hand with all other project considerations. This particular aspect of the planning has been well-reported on other occasions and considerable information on it is readily available.

Jan 1, 1972

By Paul H. Johnson

A field investigation was undertaken to study some of the. chemical and hydrological aspects of leaching an impermeable copper sulfide waste dump. Samples, obtained by means of a Becker pneumatic drill from Kennecott's Chino "J" dump, near Silver City, New Mexico, were analyzed for their moisture and soluble-salt content, Fe +2 , Fe +3, Cu +2 , and H in their interstitial solutions and non-water - soluble Fe, Cu, and S in their rinsed residues. Conclusions were drawn from these data concerning the overall chemistry of impermeable-dump leaching and the hydrological characteristics of the dump.

Jan 1, 1970