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By K. N. Han

Copper and nickel are extracted from their elemental state, complex sulfides, ores, and other materials such as scrap by leaching them with a solution containing halogen salts - bromine/bromide, and/or iodide/iodine, oxygen and sodium or potassium nitrate. This US patented process is extremely effective yielding 98% recovery in15 minutes for the treatment of chalcopyrite and pentlandite in an autoclave at a temperature of 100°C - 150°C.

Jan 1, 2003

By L. B. Hales

Color video or digital cameras have been installed over flotation cells to monitor color, bubble size, froth movement, and other characteristics. These systems are designed so that the camera provides flotation performance information just as any other sensor might. Factorial tests have been run to monitor and measure the variation in froth characteristics as a function of flotation control settings. Ultimately, it is envisioned that froth image sensors can be used to monitor and control the flotation performance as effectively and for less cost than current analytical systems.

Jan 1, 1999

By B. D. Nichols, R. Idzorek, W. S. Gregory

A numerical procedure to model flow networks using a node-based approach is discussed, and the analysis encompasses both steady-state and transient solutions. A family of computer codes has been developed using the node-based approach. This technique is illustrated by applying two of the computer codes to mine ventilation networks.

Jan 1, 1987

By K. N. Hebbar, R. G. Reddy

Spent potliners (SPL) were declared hazardous waste under RCRA (K088) in July, 1990. The glass formation characteristics of the SPL was studied. The SPL glassy matrix were analyzed using X-ray diffraction and optical microscopy. Results showed that SPL can be fixed in a glassy matrix with the addition of sand and limestone. The optimum amounts of additives were determined for obtaining the best glass formation characteristics.

Jan 1, 1995

By D. J. Shields

The Sustainable Minerals Roundtable was established in 1999 to develop a set of national level indicators to measure the contributions of mineral and energy systems to sustainable development in the USA. The U.S. Forest Service and the U.S. Geological Survey are sponsors of the Sustainable Minerals Roundtable, with meetings convened by the University of Nevada, Reno. Eighteen meetings have been held in various regions of the United States to receive input from different communities of interest. Indicators are being prepared under four criteria: legal and institutional, productive capacity, environmental impact, and socio-economic. This paper reviews the process followed by the Sustainable Minerals Roundtable, and presents the priority indicators.

Jan 1, 2003

By Stephen Navin, Pablo Ferradas, Carlos Silvestri, Alexander Markov, Jon Kaneshiro

In the high Andes of Peru, two tunnels are being constructed totaling nine kilometers in length at an elevation of over 4,500 meters. The tunnels convey freezing and crystal-clear waters from rainfalls, streams, and lakes for the consumption of Lima. The drill and blast 3-meter wide by 4-meter high tunnels are being driven from both ends through folded and sheared volcanic tuff, andesite, agglomerate,and limestone, where groundwater inflow is high. This paper describes the design geological and groundwater inflow investigations and construction.

Jan 1, 1999

By Gordon F. Revey, Dan Harrison

Hanging Lake Joint Venture recently excavated two conventional 12.8 m (42 foot) diameter highway tunnels in the difficult ground conditions of Glenwood Canyon, Colorado. This paper outlines the type and success of the various Controlled Blasting Techniques that were used to minimize overbreak in the portal and tunnel excavations. The different Smoothwall and Cushion Charge loads used in the different ground types are described in detail. Delay Timing and Drilling Pattern variations are also discussed.

Jan 1, 1991

By Yoginder P. Chugh

The mining methods used at many opencast brown coal mines in Poland and the German Democratic Republic are not used in the US to any extent. Using bucketwheel excavators, bucket chain excavators, and mobile conveyor bridges, the mining techniques may offer efficient, economic alternatives for operators in the US. These mining methods were observed during visits to several open-cast brown coal mines in Eastern Europe over the past two years. Some of them may be particularly attractive for the large lignite mines being planned in North Dakota and Texas.

Jan 11, 1980

By Q. X. Yun

This paper presents a new approach to optimize the transportation system in open-pit mines. The new approach employs artificial intelligence, fuzzy sets, dynamic programming and CAD technique to determine the transportation system. The determination consists of 4 phases: initial selection, road alignment, final decision .and open-pit drawing.

Jan 1, 1992

By Sidney M. Cohen

This paper describes an economical method of upgrading a clay deposit using conventional separation processes into a suitable cement plant feed. The natural size difference of clay and silica in the clay deposit is utilized in the dry air classification device. A case study in which the raw material from a clay deposit is converted into a portland cement plant feed is presented.

Jan 1, 1983

By J. L. Post

A near-surface body of readily available Na-montmorillonite is located about 24 km (15 miles) southeast of Fallon, NV. The clay, which forms an irregular deposit about 4.8 km (3 miles) long, lies in altered rhyolite within a fault zone. The clay is similar to Wyoming bentonite but is less uniform in composition and contains less MgO and more Fe2O3 in its crystal structure. The clay interlayer cation population can be estimated by using a modified DTA procedure. With selective mining, the industrial properties of the Nevada clay are adequate for use as drilling mud, in foundry applications and as a sealant for hazardous wastes and canals.

Jan 1, 1997

By C. R. Rinschler, G. R. S. Smith

A high-strength, industrial-grade membrane filter- cloth capable of high flow rates and sub-micrometric particle retention has been developed. A filtration system using this filter- combined with special filtration techniques and using tubular-filters makes possible the filtration of many difficult-to-jilter slurries. Small, discrete, slowly-settling particles are formed into filter cakes that when pulsed of the membrane filter cloth do not redisperse but settle rapidly to form a dense filter under- flow. A positive separation of solids from liquids is obtained.

Jan 1, 1991

By Bob Newbery, Kenneth W. P. Eng. Kolthammer

SUMMARY Reference is made to the reasons for drying and the equipment is described that is available from which the engineer can make a selection. The factors affecting this decision are described. In the case of drying, design and sizing are ultimately developed empirically and no theoretical approach has been advanced.

Jan 1, 1986

By J. Steven Whisler

Corporate managers are facing increasingly demanding challenges as they seek to ensure compliance with environmental laws. Management also must deal with new liabilities created by environmental laws. These laws provide both private groups and governmental agencies with access to the courts to seek penalties, compliance orders, cleanups, or to forestall developments that could affect ecosystems. Environmental laws and liabilities are also affecting commercial transactions, including the availability of financing. Corporate managers must develop new and innovative methods to address these challenges in order to assure both sustainable industrial growth and stewardship of the environment.

Jan 1, 1991

By S. D. Bearden

The world's barite reserve base is adequate for at least 100 years at the current consumption rate. China, India and the United States are expected to remain the leading producing countries, and the United States will continue to be the largest consumer. None of the known substitutes for barium sulfate are expected to impact existing applications. World production in 1995 was 4.41 Mt (4.86 million st), which is about 50% of capacity. Consumption is directly proportional to hydrocarbon well installation activity. Imports are expected to continue to supply more than half of the US requirements.

Jan 1, 1997

By R. L. McNearny, K. A. Barker

A study was conducted to compare physical and numerical models of the block-caving mining method. Results from the numerical analysis closely simulated the blocky behavior of the physical model, including bridging and interlocking of the simulated orebody during draw. The draw-down patterns and the rate of draw developed during numerical modeling also closely simulated the physical models. An unexpected result from the numerical modeling was the development of a zone of downward deflection which preceded the development of the zone of material movement.

Jan 1, 1999

By Daniel Tempelis, Tom Freeman, Eric Fordham, John Shamma, Steven Duke

The Arrowhead Tunnels in southern California are being completed by MWD under stringent groundwater in?ow limits established by the U.S. Forest Service. Pre-excavation grouting, new TBMs and a bolted, gasketed, pre-cast concrete segment initial lining are employed to control water in?ows. The effectiveness of prescribed water control measures was analyzed using conservative assumptions with the analytical techniques described by Goodman (1964), Heuer (1995), and numerical modeling. Analyses results suggest groundwater in?ows to the tunnels can be maintained well below the limits with aggressive pre-excavation grouting balanced against a reasonable rate of advance and quality erection of the initial lining system.

Jan 1, 2003

By T. Altman

Using theory of network planning together with graph theory, an algorithm is presented that creates canonical diagrams for mine ventilation networks (M VN). The data generated by the algorithm is used in the construction and plotting phases of a program that automatically plots the canonical diagrams, which can then be used for further studies of a given MVN.

Jan 1, 1988

By G. E. Burrer, D. Malhotra, T. E. Irwin, S. Johnson

Climax byproduct-plant tailing assayed 0.019% WO3. Pilot-plant and laboratory tests were performed to investigate the possibility of recovering additional tungsten values from the byproduct-plant tailing. The methodology used in the study and the results of this investigation are discussed.

Jan 1, 1987

By David A. Rice, Scott A. Shuey, William K. Tolley

The U.S. Bureau of Mines (USBM) is developing new dewatering technology to permit the recycling of iron values contained in wet steel plant sludges. In laboratory tests, Q-BOP fume sludge was dewatered to 12% moisture by displacing water with acetone in a plate-and-frame pressure filter. Acetone is reclaimed through distillation at lower cost than conventional thermal drying of the sludge. The projected additional energy requirement for acetone treatment of the sludge, including acetone recovery, is $5 to $7 per dry ton.

Jan 1, 1995