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By R. D. Miller, D. W. Steeples

Seismic reflection is a powerful geophysical exploration method that has been in widespread use in the petroleum industry for more than 60 years. This paper addresses some basic principles of the method and its application at depths shallower than 30 m (100 ft). Since 1980, the shallow reflection technique has been increasingly used for engineering and environmental problems, such as mapping bedrock beneath alluvium and delineating intra-alluvial features near hazardous waste sites, detecting voids in coal and karst, defining the top of the saturated zone and mapping shallow faults. New applications will be added with improved resolution and increased cost-effectiveness.

Jan 1, 1994

By W. H. B. Blackburn, D. M. S. Bhatia

Twenty-six in situ analyses of cubic galena crystals from a Mississippi Valley-type deposit were undertaken with a laser microprobe emission spectrograph to study the variation of nine trace elements from the crystal center to its periphery, both along the diagonal and vertical. The general trend is an outward increase in the concentrations of Ag, Ga, Ge and In, with As showing the opposite trend. Bi, Cd and Sn showed no discernable trends. Sb was not detected. These variation patterns may serve as a model for similar studies of other Mississippi Valley-type deposits.

Jan 1, 1987

By Maureen D. Carmen, Joseph L. Zaluski, Gladys Beck Green

The Federal Surface Mining Control and Reclamation Act (SMCRA) requires a surface mine operator to post a performance bond before a mining permit can be issued to that operator. Release of that bond is contingent upon the completion of all required reclamation, restoration, and abatement work on the permit area. This paper explores the requirements of each of the three phases of reclamation under SMCRA, as well as provisions of four exemplar state regulations of four states that have been granted "primacy" under SMCRA. Successful completion of these requirements is a condition pre cedent to the release of performance bond liability. Failure to secure a timely bond release will have an ad verse impact on an operator's other mine permitting activities throughout the United States.

Jan 1, 1991

By S. Nickson, M. Grenon

Oriented borehole data provide the means to characterize a rock mass. In this paper, the geomechanical caving potential of a hard rock mine project is investigated. In particular, the influence of random joints to the resulting block size distributions is addressed. The implications of this approach in preliminary investigations on the choice of mining methods are discussed with reference to one site.

Jan 1, 2003

By K. G. Sutterer, R. J. Sweigard, U. Graham, T. C. Hopkins

The prevalent use of coal combustion byproducts in engineering applications has been with Class C and Class F fly ash as admixtures in structural concrete. But, the use of fly ash and bottom ash byproducts from modern desulfurization processes is receiving increased attention. The University of Kentucky has been conducting research into civil- and mining-engineering applications of these products. The studies have included extensive investigation of the geomechanical behavior of the materials and the effect of mineralogy on this behavior. These studies indicate important mineralogical considerations in the selection of materials for a specific application and highlight the importance of quality control before and during usage on specific projects.

Jan 1, 1998

By G. Kazonich, S. L. McGill, J. W. Walkiewicz

Naturally occurring minerals and reagent-grade compounds were tested to determine their receptivity to microwave heating. The maximum temperature achieved for the samples and the time required to reach temperature are reported. A description of the microwave oven and a thermocouple technique that accurately measures and continuously records the temperature of samples during irradiation are reported. Extractive applications using the generated microwave data were investigated. Stress fracturing at mineral grain boundaries in a gangue matrix was shown. This should significantly affect grinding energy requirements and liberation properties. A method to produce a magnetic phase on pyrite surfaces, a method of using microwave heating to retort cinnabar concentrate, and a roast-leaching microwave treatment of chalcopyrite ore are described.

Jan 1, 1987

By A. S. Moss, J. Linkous

Where difficult shaft sinking conditions exist, it may be appropriate to use a blind drilling technique. The success of the method is in part due to the presence of a drilling mud which fills the shaft void during excavation. The mud performs two important functions with respect to shaft stability: it reduces the influence of groundwater; and, due to the mud weight, gives a positive sup- port to the shaft walls. The application of the method is illustrated by a case history which traces the development of a shaft from the initial investigation to determine the shaft location, through the evaluation of wall stability and mud requirements, to the shaft sinking contract and actual conditions encountered.

Jan 1, 1986

By W. Trask

The state of the art in crawler transporters for loads to 3 kt (3300 st) is sufficiently advanced to allow compilation of job cost figures showing the economics of tracked vehicle use under a wide variety of circumstances. Initial costs, cost per ton of capacity, and operational and maintenance expenses are presented. Data is derived from participation by the Neil F. Lampson Co. in more than 3 Mt - km (2.05 million st - mile) of crawler operation during the past 16 years. The effects of economics on future design trends will be examined with particular reference to versatility, portability, and capacity.

Jan 1, 1987

By W. V. Harper

The travel path of a freed radioactive particle in an aquifer must be estimated from a limited number of available samples. This paper discusses geostatistical methods that minimize the 'uncertainty' associated with the predicted hydrologic surfaces and the predicted travel path. However, any estimation method will produce a single smooth predicted path. This 'sensitivity' will he evaluated using a geostatistical simulation method. The techniques will be illustrated using published data from the Wolfcamp and Pennsylvanian aquifers in the northern Texas Panhandle.

Jan 1, 1990

By J. G. Groppo, B. K. Parekh

Eastern US oil shale contains approximately 10 to 12 gallons of oil per ton and 7 to 10% pyritic sulfur. Physical beneficiation of these low grade shales using froth flotation provides a high grade material that makes extraction of oil more economically attractive. The Alabama oil shale used in the present study contained 16.46% organic carbon and 14.5 gallons of oil per ton as determined by Fischer assay. Liberation size of the kerogen was estimated at 10 µm. `Ken-Flote' column flotation technology provided a high grade concentrate containing as much as 60% organic carbon. However, carbon recovery was about 60%. Carbon recovery was improved to 75-85% while maintaining concentrate grades in excess of 40% carbon by providing longer retention time in the column, which facilitated effective bubble-particle collision and attachment.

Jan 1, 1994

By M. Rosenshine, R. W. Barbaro

This paper presents a cyclic queueing model that evaluates the productivity of a shovel-truck materials haulage system. For a cyclic queueing problem with exponentially distributed service times, a cyclic queueing model provides exact solutions in a fraction of the time that simulation takes to produce an approximate solution. The model is applied to an example problem, and the results are validated with simulation. Simulation is used to show that the assumption of exponentially distributed service times and steady state are not serious problems. A cyclic queueing model can be used to quickly obtain an accurate assessment of the productivity of a shovel-truck system.

Jan 1, 1988

By V. J. Matta, A. A. Pincheira, I. A. Reghezza, Ch. J. Vergara

The growth of solvent extraction in Chile has been astonishing during the last years and has been established as a very successful technology. However, there are still limitations that must be improved, mainly, the problem of carry over from one phase to the other and the losses of organic reagent associated with the crud formation. These are problems that our company has been taking care, solving them with high efficiency and low costs, allowing important increases in the copper output of our plants and capital savings by means of the optimization of the use of nonproductive units in the SX plants.

Jan 1, 1998

By B Faulkner, M. Weinecke

In 1997, Sveciala began a program to develop a process to convert waste tires into valuable commodities. A review of numerous approaches revealed shortcomings that were process related or mechanical related, while some of the approaches emphasized he production of low-value products. A market study revealed that a process that could produce a good grade of carbon black would be economically feasible. This paper discusses the laboratory and pilot-plant development and commercial plant design of such a process.

Jan 1, 2002

By S. Chunhui, W. Anbin, R. B. Cook

The Xicheng is one of China's largest lead-zinc (Pb-Zn) districts with known minable reserves in excess of 10 Mt (11 million st). The centrally located Changba-Lijiagou and nearby deposits are representative of the district. They consist of stratiform and stratabound zones of pyrite-sphalerite-galena mineralization within deformed, moderately metamorphosed Middle Devonian clastic and carbonate units. When considered with other similar districts that extend for several hundred kilometers to the east, a major episode of Devonian sedimentary exhalative mineralization is indicated.

Jan 1, 1992

By H. M. Lima, P. Wathern

There are many different words to describe mine closure, including rehabilitation, reclamation, restoration and decommissioning. Closing mining operations, mainly open pit mines, has required resolution of numerous issues. Mine closure plans involve environmental-protection issues, regulatory issues and community issues. The obvious, and often most expensive of them, is the physical rehabilitation of the disturbances and the elimination of long-term commitments and maintenance. This paper outlines mine closure planning and its important component, mine-site rehabilitation. Community consultation and involvement are also referred to as an important component of the mine-closure plans, which are required to ensure satisfactory mine site rehabilitation. Considerations of socioeconomic impact of mine closure and long-term responsibilities are presented.

Jan 1, 2000

By K. N. Han

A kinetic model for the batch leaching of various metals using different lixiviants was developed. The overall material balances for the reactants and products at the solid/ liquid interface were formulated for various types of heterogeneous reactions at the interface. The solutions to these mass balances are identified analytically, as well as numerically. Applications of these numerical solutions to various leaching systems using rotating discs or powders are discussed. The metal-dissolution systems addressed include cobalt, nickel and copper in acid, cyanide and ammoniacal solutions.

Jan 1, 1996

By M. S. Celik, G. Onal, S. Atak, A. A. Abramov

An oolitic phosphate ore composed of phosphate (mainly francolite) and carbonates as gangue has been tested for the suitability of the reverse flotation process. The samples were first ground autogeneously followed by the reverse flotation process. While the carbonates were floated by sodium oleate the phosphate was depressed by phosphoric acid. The effect of particle size, reagents type and concentration on flotation recoveries have been investigated to determine the optimum conditions. By this process, a run-of-mine ore containing 16.72 % P205 was upgraded to 28.00% P205 with a recovery of 77.0% The mechanism of optimum flotation with phosphoric acid observed at pH 6.3 is explained based on a relationship involving surface potentials and the ratio of required collector concentrations for the respective minerals.

Jan 1, 1993

By G. Pierson

Explanations for commodity price levels (or movements) commonly focus on the fundamentals of supply and demand otherwise they are simply assigned to speculative activity. Comparisons of metal-price histories to monetary and other economic data support the argument that the supply of and demand for money are no less important in the determination of price than are the supply and demand of the commodity itself. That these relationships should exist is evident in the price identity and they are consistent with monetary theory. The patterns developed have limited usefulness as predictors, but their recognition is essential for the construction of price scenarios for planning purposes.

Jan 1, 1998

By Jianliang Li, Jan M. Mutmansky

This study analyzed laboratory comminution techniques for respirable mine dust generation and the properties of the resulting dusts. It was the objective of the study to determine the suitability of the resulting dusts in reflecting the properties of natural airborne dust. This paper deals specifically with the amount of contamination introduced into the generated dust as a result of abrasion when using nine different grinding methods. The analysis was made by comparing the content of 25 chemical elements in the lab-generated dusts with the same elements in the airborne coal mine dusts. It was found that all the lab-generated dusts possessed contamination but that several methods produced smaller percentages of contamination and that the residence time in the grinding device was an important factor in the contamination levels.

Jan 1, 1992

By Violetta Pavlova

Knowledge of geometrical properties of blocks in a hard jointed rock among other things is of considerable importance for prediction of rock mass behavior and for its exploitation. This paper presents a new approach to obtain the information about percentage of blocks with desirable geometrical properties in a jointed rock mass extending through a large region of interest. A model of a rock mass separated by finite number of systems of parallel plane discontinuities which form discrete blocks is discussed. A computational procedure has been derived to analyze the volume and shape distribution of blocks in the rock mass.

Jan 1, 1992