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By Joseph R. Hatch

Previous studies of the Thompson and Temperly ore bodies show alteration aureoles in the Middle Ordovician host-rock limestones, dolomites and shales extending laterally as much as 60m from the ore. Thickness, texture, carbonate and clay mineralogy, major-, minor-, and trace-element contents; and carbonate carbon and carbonate oxygen Isotope compositions of the host rocks all have been significantly altered by hydrothermal processes. Organic geochemical analyses of samples from the basal 8-cm-thick carbonaceous shale bed and immediately overlying limestone bed of the Quimbys Mill Member of the Platteville Formation, collected from within the ore, the alteration aureole, and the unaltered country rock show: 1) solution of carbonates and residual concentration of organic matter, 2) decreases in the volatile (Si) and pyrolytic (S2) hydrocarbon yields In samples of the basal shale from within the ore, 3) decreases in the relative amounts of the lower molecular weight (<nC25) saturated hydrocarbons in samples from the ore, and 4) no changes in either the organic carbon isotope composition or the Rock-Eval or biomarker thermal maturation Indicators. In light of the 125-170°C depositional temperatures documented for the early marmatitic sphalerltes in these deposits by fluid Inclusion studies, the lack of thermal alteration of the organic matter suggests a relatively short mineralization episode, a conclusion supported by the relatively simple sphalerite band stratigraphy. The decreases in the volatile and pyrolytic hydrocarbon yields for shale samples from the ore supports a model for mineral deposition which obtains sulfide through reaction of brine sulfate and indigenous organic matter.

Jan 1, 2013

By W. White

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the author elect, he may distribute copies at the time of the Symposium.

Jan 1, 1986

By Wang Zuoyu

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the author elect, he may distribute copies to the time of the Symposium.

Jan 1, 1986

By Michael M. Maier

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the author elect, he may distribute copies at the time of the Symposium.

Jan 1, 1986

By David D. Rabb

Leaching or solution mining, a relatively simple and economical process for beneficiating metallic ores, is likely to find increasing application in the treatment of low-grade ores that are impractical to mine by any other means. This process may be carried out in two different ways: 1. Dump leaching, where the ore is moved from its original location to be leached at another site. 2. In situ leaching, where the ore is leached in place by introducing the leach solution at the top, letting it flow down through the ore under gravity, and then recovering it plus the dissolved metals it contains.

Jan 1, 1969

By B. Strickland

The decision to accelerate development of Stillwater Mining&apos;s East Boulder Mine was made in March of 1998. It required the completion of conceptual designs by July of 1998. This was accomplished through teamwork and close cooperation of mine personnel, engineering firms and vendors, all working toward the common goal of developing an efficient and workable design. Early in the project, representatives of Stillwater Mining, Kilborn International, Parsons Brinckerhoff Transit and Rail Systems, Continental Conveyor, and H.A. Simons met to develop methods to bring the mine into production at a highly accelerated rate and to solve potential bottlenecks, including the movement of personnel, materials, and muck through a 5.6 km (3-1/2 mile) adit. This interaction, including companies not normally associated with the mining industry, led to innovative approaches and designs produced by Kilborn Engineering and Stillwater Mining.

Jan 1, 1999

By W.A. van der Westhuizen

Mineral resource management has become a well used phrase in the mining and minerals industry. Mineral resource managers are being appointed in many mining and mining-related organisations. Every mineral resource manager has his/her own ideas regarding what MRM means. There seems to be a tendency to define MRM close to home; geology would apply MRM principles to their environment and so will metallurgy, planning, mining, survey and every discipline and participant in the mining value chain. What do we do in the MRM environment and what do we aim to achieve? Surely we must have goals: what are they? Is value tracking MRM? What about best practices? Let us start at the beginning: what do we want to achieve in any mining operation? The minerals industry would like to make money, now and in the future. This calls for serious management inputs. The most important aspect is a holistic management approach regarding the total mining value chain. Process optimisation follows with application of Mineral Resource Throughput Management (MRTM) and Process Flow Management principles. Once flow processes have been established the necessary condition driven standards and measurements will be installed to ensure continuity in applicable processes.

Jan 1, 2012

By G. M. Wenberg

Bacterial leaching of copper and uranium is practiced in environments containing available sulfur and iron and having a strong acidic reaction. However, many mineral deposits do not have these conditions; the chalcocite and native copper ores in Michigan&apos;s Upper Peninsula are examples. Bacterial and fungal populations were observed in samples taken from the White Pine Copper Company tailing pond and mine, and isolates were prepared of the dominant species. The isolates were then screened for solubilization of copper from tailing, ore, and concentrate during incuba¬tion in a carbon and nitrogen supplying medium. Certain Penicillium fungi solubilized significant amounts of copper under neutral to slightly acidic conditions. Leaching apparently was accomplished by release into the medium of metabolites which chelated with the copper.- The process was found to be highly dependent upon the medium and the concentration of copper in the source material. The paper describes sampling and screening techniques, presents the results of experimentation to standardize procedures and maximize the yield of copper, and discusses the nature of the leaching process. This preliminary research reveals a biological process which may find use in mineral extractions but whether it can be applied economically remains to be determined.

Jan 1, 1969

By D. S. Choi

Underground production of coal by longwall methods has increased significantly in the last few years and will very likely continue to: increase. There are several reasons for this. First, as mining moves into seams having greater overburden, roof exposure must be reduced since support will become&apos; increasingly expensive. Secondly, the growing demand for coal has forced the coal industry to seek alternative, more productive, coal mining methods. In addition, the longwall method greatly simplifies the underground ventilation network. This paper addresses itself to the design of longwall development headings, particularly to those of the United States where multiple development headings are required by law. The most burdensome problem encountered in many longwall mining installations is deterioration of the tailgate due to the combined effect from, the active longwall gob and the old gob made by mining the previous panel.1 Portions of the tailgate entry are sometimes closed to such a degree that extensive repair work is necessary to keep the entry in usable condition. The purpose of this paper is to present the result of a study in progress which combines field measurements with numerical model analysis to reduce the cost of maintaining tailgate entries in longwall mining systems.

Jan 1, 1975

By Salim Akhtar

The operation of a mineral processing plant with a complex flowsheet is represented by a mathematical operator. Such a representation permits a quantitative evaluation and monitoring of the separation processes in different sections of a processing plant, and gives an overall separation efficiency of the plant.

Jan 1, 1973

By Roy J. Greenfield

A highly undesirable side effect of the mining of coal is the release of acid forming chemicals into the ground water system. The disturbance of the ground during mining allows water to flow through the coal bearing strata and mine refuge where it absorbs iron and sulfide ions and thus becomes highly acidic. The highly acid mine water can then contaminate water supplies and can destroy many of the recreational uses of Pennsylvania&apos;s waterways. A great deal of effort has been expended to develop methods of controlling groundwater pollution from mine drainage. At the Pennsylvania State University there has been an ongoing effort to under- stand the chemistry of acid mine water formation and the hydrologic environment in which the acidic water migrates from the mine source into the ground water system. As a support to the hydrologic studies, geophysical studies have been used to help determine the geologic structure of the areas under study which are contaminated by acid water. In addition, the geophysical work has been used to define the type of information geophysical methods can give to determine which geophysical methods are most useful and to develop geophysical field procedures.

Jan 1, 1973

By Sam H. Patterson

This paper is concerned primarily with the kaolin deposits extending northwestward from Macon, Ga., which is in the western part of the Irwinton district (fig. 1). These deposits are in a belt of kaolin districts extending along the inner edge of the Coastal Plain from the Aiken district, S. C., southwestward to the vicinity of Macon, a distance of 150 miles (250 km). Large kaolin deposits associated with bauxite also occur in an extension of this belt southwestward from Macon as far as the Eufaula district, Ala., a distance of about 130 miles (208 km). The belt splits away from the inner edge of the Coastal Plain in a southwesterly direction from Macon; the Eufaula district is approximately 50 miles (80 km) south of the contact of Coastal Plain sedimentary rocks with much older crystalline rocks. Structure The strata of Cretaceous and Tertiary age containing the kaolin deposits all dip gently seaward irom the landward edge of the sedimentary rocks. The dip of the Cretaceous strata is about 25 feet per mile (4.9 m per km). The dip of Tertiary strata is about 15 feet per mile (2.1 m per km). In places, the Tertiary strata overlap the older sedimentary beds and rest directly on the crystalline rocks. Faults having a few feet of displacement have been observed in several mines, but no major faulting is known in the area.

Jan 1, 1977

By R. E. Miller

Accelerometers and pressure transducers mounted in suspension components can be used to monitor the ride of haulage trucks. Presently, it is difficult to tell what caused a jolt to the truck using either pressure or acceleration data alone. When information from a Global Positioning System is recorded at the same time as shock pressures or acceleration data, then the exact location of an event can be determined. Mine management can then determine what caused the jolt to the truck.

Jan 1, 1999

By Juan L. Yarmuch, Gonzalo Sepulveda

Medium- and short-term mine planning holds immense significance in optimizing production and resource utilization. It serves as a vital link between the long-term strategic plans and the day-to-day operational activities of a mine. In this context, a mathematical formulation is proposed to incorporate mining width constraints into the production scheduling process, aiming to maximize the net present value (NPV) of the schedule while ensuring enough room for the operation of mining equipment.

Jul 1, 2024

By M. A. Bothwell

The purpose of this paper is to describe the methods used to select mill discharge screens, and to outline factors which should be taken into consideration when choosing screens for this application.

Jan 1, 2001

By Mark L. Mott, Michael P. Synder

The Mine Safety and Health Administration has developed a program to improve the decision making process of personnel involved in mine emergency situations. The Mine Emergency Responsiveness Development Program (MERD) has been designed specifically for fires and explosions in underground mines. This program addresses the responsibilities and organizational requirements that are necessary during rescue and recovery operations of a mine emergency . Specific skills and knowledge are required to manage an organization of personnel under conditions of intense stress, such as a mine fire or explosion. As a result, the MERD program develops these skills by providing role playing emergency simulations. This role playing provides the participants with the opportunity to experience problems, explore solutions and interact with other personalities which may exist during mine emergency situations. This paper presents the standard procedures for the MERD program developed by the Ventilation Division of the Pittsburgh Health Technology Center.

Jan 1, 1991

By A. Russell, M. N. Hughes, Jack Barrett

The bacterial oxidation of arsenopyrite has been shown to be an efficient, economic and environmentally acceptable method for the liberation of any gold content . The mechanism of the process is not certain but is usually considered to involve direct and indirect reactions with respect to bacterial involvement. The direct reactions are those in which the bacteria attached to the mineral surface cause its dissolution, with dioxygen being the oxidant. The iron(III) produced in solution is the chemical oxidant in the so-called indirect reactions. Barrett et al 2 showed that a synthetic bio-oxidation solution (with no cells present) could dissolve up to 15% of an arsenopyrite sample, the products of the chemical oxidation being iron(II) and arsenic(III). This paper describes an extension of the investigation of the chemical process and its imp! ication for the mechanism of the bio-oxidation of arsenopyrite.

Jan 1, 1990

By Hugh K. Herbert, R. John Watling

Laser Ablation-Inductively Coupled Plasma-Mass Spectrom­etry (LA-ICP-MS) has been used successfully to "fingerprint" gold in forensic investigations within Australia and abroad. By comparison of the elemental associations it has been possible to relate gold to specific mineralising events, mines, bullion samples and fabricated articles. The methodology facilitates identification of the provenance of gold thereby providing definitive scientific evidence in criminal investigations. "Gold" samples for analysis span a wide range of materials with many requiring exhaustive prior separation and treatment to present the contained gold in a chemically "unmodified" state, and in a form, suitable for LA-ICP-MS fingerprinting. The quality of the fingerprint, and hence its value in evidence, is directly related to the rigours of prior sample preparation and evaluation, to an appreciation of the history of the gold under investigation, and to the skill of the analyst.

Jan 1, 1995

By Betty L. Gibbs

The ultimate objective of mine design is to determine the development and untilization of mining resources. Computer Aided Design (CAD) and automated mapping are becoming very popular in engineering and in mining. Any computer program which produces a design or model with the interaction of an engineer can be considered computer-aided design (CAD), but&apos; the term CAD is often associated with interactive graphic design and mapping capabilities. Graphics can be effectively used to describe and model two-or-three dimensional mine workings, orebodies, and geologic structures. Interactive computer graphics is applied to mine design with a combination of deposit modeling techniques and the use of AutoCAD for interactive graphics and mapping. The combined system can perform a large part of the calculations and drafting work for geologic and mining design. Using computer calculation and graphics techniques, comparisons of alternatives, can be made quickly.

Jan 1, 1989

By Jan M. Mutmansky

The application of computers and operations research to mine planning problems has changed and progressed significantly over the last several decades with a continuing growth and increased breadth of applications being quite evident. A scan of the volume associated with the 1969 APCOM published two decades ago (Weiss, 1969) indicates that the primary applications in mining were often in the areas of short-term and long-term planning and production scheduling. The applications at that time were oriented toward underground and surface mining, but block and other mine sequencing and scheduling problems for large open pit mines were perhaps the most popular target for the operations research approach. A variety of operations research techniques were used at that time with heuristic models, mathematical programming models and simulation programs all being commonplace. The computers used were usually mainframe models which were of ten shared by accounting, engineering, planning and research groups.

Jan 1, 1989