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By N. R. Paterson, D. A. MacFadyen

A late-1980 airborne EM/magnetic method test over the State Line kimberlite area of Colorado-Wyoming shows weak but recognizable anomalous responses to the known pipes. The magnetic survey indicates the presence of several shallow subsurface bodies adjacent to the known kimberlites, which are interpreted as possible blind diatremes. The survey data, in profile and contoured map form, has been correlated with geological map information available at the time. It can serve as the basis for reexamining kimberlite distribution in the area, taking into account geological findings during the recent work on known bodies.

Jan 1, 1987

By Thomas A. Wheeler, Robert O. Keys

The choice of the flotation reagent that suits a particular coal has become more complicated with the development of new, more efficient reagents. Frothers and conditioning reagents, in particular, have experienced a dramatic reevaluation of their role in floating various types of coals. This paper offers a better understanding of how each of the following factors contributes to the reagent selection: 1. Natural Flotability 2. Degree of Oxidation 3. Size Distribution 4. Percent Solids in Feed Slurry 5. Fluctuations in Plant Feed 6. Limitations on Froth Handling 7. Clean Coal Specifications 8. Ash Content in Feed a) discrete ashable minerals b) inherent ashable minerals 9. Water Chemistry 10. Petrographic Composition of Coal 11. Free-Swelling Index 12. Convictions of Customer The application of conditioning reagents - both promoters and emulsifiers can substantially improve the coal recovery. Some low-rank, hydrophylic coal, previously considered unfloatable can be economically recovered with the use of the proper reagent.

Jan 1, 1986

By Daniel L. Hanson

This paper presents case histories of the construction of four large diameter circular shafts using reinforced concrete ring beams as the primary internal support system. The case histories pertain to concrete ring beam systems which have been successfully used in shafts up to 130 feet in diameter and 75 feet deep. Soldier pile and lagging, and driven steel piling earth retaining systems using ring beams, are discussed together with the cost savings associated with using concrete ring beams. Soil conditions encountered at the case history sites are discussed together with the development of design criteria for each shaft. Instrumentation data obtained at one site are also presented.

Jan 1, 1987

By D. B. Dreisinger, H. J. Sohn, J. S. Sohn, G. A. Kordosky

The transport of lithium through a supported liquid membrane was studied with a mixture of D2EHPA and TBP in kerosene as a mobile carrier. In the flat- sheet supported liquid membrane(SLM) system, experiments were carried out to investigate the effects of concentration of mobile carriers in the membrane solution, hydrogen ion in the feed solution, and temperature on the transport of lithium. Experimental results agreed well with a transport model for permeating lithium across the liquid membrane. The permeation rates of lithium can be explained in terms of diffusion of a Li-complex through the membrane phase. For a practical application of an SLM method, a hollow fiber module has been used and lithium can be concentrated more than three times in 24 hours.

Jan 1, 1993

By G. G. Marino, Z. R. Widup

Marino Engineering Associates, Inc. (MEA) was asked to determine the effects of mining beneath a proposed roadway structure. In order to determine the subsidence potential and the magnitude of the mine stabilization costs it is important to know whether underground mining is present, and if so, to what a real extent. The site investigated had the potential to have mining in three different coal seams. To determine where mining was present MEAÕs borehole radar system was used. In summary, the borehole radar subsurface investigation validated that the available mine map in the most shallow coal seam was fairly accurate despite its age (1888), found no mining in the underlying coal seam and detected an area of unknown mining at a depth of about 300 ft in the lowest coal seam which was verified by subsequent drilling.

Jan 1, 2004

By P. F. Ziemkiewicz, A. S. Knox

Large-scale use of CCBs in mine environments involves filling surface and underground coal mines with ash to address hydraulic problems, AMD, backfilling and subsidence. The environmental risk of land filling CCBs is generally evaluated by the Toxic Characteristics Leaching Procedure (TCLP) or the Synthetic Precipitation Leaching Procedure (SPLP). However, there is doubt regarding the applicability of these tests to long-term CCBs leaching behavior in groundwater associated with coal mines. The Mine Water Leaching Procedure (MWLP) was developed to provide a site specific risk assessment tool. The MWL Pprocedure is presented in this paper and compared with TCLP as a study.

Jan 1, 2003

By R. L. Brown

The Buchans mining district is located roughly at the center of the island of Newfoundland and contains some 18 separate mineral deposits. The first of these deposits was discovered in 1905, the latest discovery having been made in 1979. To the present (1983), some 16 Mt (17.7 million st) grading 1.33% Cu, 7.5% Pb, 14.5% Zn, 115 g/ t (3.7 oz per ton) Ag, and 1.4 g/t (0.04 oz per ton) Au have been mined. Mining operations are now largely terminated, but a few hundred thousand tons of economically marginal reserves may be mined in a salvage operation. The Geological Association of Canada Special Paper No. 22, "The Buchans Orebodies, 50 years of Mining and Exploration," contains papers which describe the history, geology, and the application of evolving geological concepts in exploration. Papers by Neary, Swanson, and Thurlow and Swanson in that volume are topical to the present discussion. Successful exploration techniques at Buchans included physical prospecting, utilization of the state-of-the-art geophysical techniques, saturation diamond drilling which was made possible by the high gross value of the existing ore, and, since 1955, diamond drilling directed by fairly well understood geological parameters. The record of discovery started in 1905 when the Buchans River deposit was found by Matty Mitchell, a prospector employed by the Anglo- Newfoundland Development Co., a British company which owned mineral rights over a very large area in the Red Indian Lake-Exploits River drainage system.

Jan 1, 1991

By Gordon I. McPhail, John D. Nelson

Tailings management represents a major portion of the cost associated with extraction of gold. For each gram of gold extracted, 150 to 200 kg of waste material is produced. Because of environmental concerns and unwillingness of society to accept environmental damage caused by poor waste management practices it has become essential to follow responsible and safe practices in tailings management. This paper presents general aspects of tailings management and discusses different techniques utilized. Characteristics of tailings and the effects that these have on stability and environmental aspects are discussed. The paper also discusses the effect of mine back-filling practices on the surface disposal of the remaining tailings fraction.

Jan 1, 1987

Contents

Jan 1, 1985

By W. E. (Bill) Stanley

Introduction This is an exciting day. It isn't often that you can find the best minds in a particular business gathered together in one place. But that is what we have here. You are the best and the brightest people there are in the business of gold mining. What we discuss at this conference confirms the major issues facing us and sets out the issues governing how our mines and mining companies will be run in the next few years. In looking over the list of papers to be given, I have noticed something. It is something that I have noticed at almost every mining convention I have ever attended. Almost every paper at this conference concerns itself with the technical side of mining. Most of us in this roan are professionals; we are either engineers, geologists, accountants or representatives of some other profession. In getting where we are today, we have had to work hard to acquire the technical skills needed for our individual professions. We are all proud of our knowledge and work hard to claim the right to be considered an expert in a particular technical field or subject area.

Jan 1, 1987

By C. W. Nelson, A. G. Moody

This paper describes the design, equipment selection and onshore fabrication of the largest facilities module ever installed in a single lift in the Gulf of Mexico. Measuring 35.5 x 70.1 x 21.3 m (110 x 230 x 70 ft), the three operating level structure houses Frasch process sulfur mining equipment and weighed nearly 49 million N (5500 tons) during lift. An operating weight of over 74 million N (8300 st) combines with bridge reactions acting on the in-place module and results in a total operating vertical load on the supporting platform deck of about 107 million N (12,000 tons). A Vierendeel truss structural system was selected for framing the module to allow maximum equipment access and routing flexibility for complex, insulated large diameter process piping. Research and finite element analysis of crimp plate siding behavior in shear was carried out during selection of siding type for the module. An interactive design sequence was carried out that incorporated in-place operational criteria, onshore fabrication considerations, complex process equipment requirements, plus load-out, ocean transport and offshore lift analyses. Project schedule dictated that design, procurement and fabrication be fast-tracked with parallel activities accelerated to the maximum extent possible. Design and construction of this largest and most complex module was done concurrently with 52 other components of the project including jackets, decks, process and living quarters modules as well as two 122 x 22 m (400 x 72 ft) sulfur tankers. Total tonnage of steel structures for the project exceeded 90.7 kt (100,000 st). The 5 kt (5500 st) mining module proved the viability and costeffectiveness of larger modules than commonly used in Gulf of Mexico waters. This technical advance can be matched with economic opportunity for other large-scale offshore installations.

Jan 1, 1994

By Christopher Haycocks

Successful ground control is an essential part of all viable underground mining operations. To a large extent ground conditions influence the choice of mining methods, percentage and cost of extraction, and often the degree of safety that can be achieved. Utilizing the computer for ground-control planning offers great potential under many diverse conditions as not only are computations facilitated, but also details of the often complex geologic and structural framework of the mine can be readily stored and retrieved. Two basic approaches have been developed for applying the computer in solving ground-control problems. The first uses an analytical method, such as the finite element technique, for solving a specific problem. The second is more general and involves storage of geologic data and application of general design equations. The latter has found wide application in stratified deposits. It is the purpose of this chapter to describe both approaches as they are used for improving the ground-control aspects of mine planning.

Jan 1, 1979

By C. W. Schultz

Introduction The Mineral Resources Institute, The University of Alabama, has for the past three years been engaged in a program to develop a beneficiation system for eastern (Devonian) oil shales. One objective of that program was to evaluate advanced technologies for effecting a kerogen-mineral matter separation. Column flotation was among the advanced technologies selected for evaluation. Early in the program it was shown that column flotation was superior to conventional (mechanical) flotation and to the other advanced technologies being evaluated. The investigation then proceeded toward the further objective of defining the optimum operating conditions for column flotation. One observation made in the course of optimization testing was that introducing the feed into the froth (above the pulp-froth interface) resulted in an improved combination of concentrate grade and kerogen recovery. This observation was reported in a previous paper (Schultz and Bates, 1989). Because the practice of maintaining the pulp froth interface below the feed point is contrary to "conventional" practice, it was decided to subject the observation to a systematic series of tests. This paper describes a recent series of tests and the results that were obtained.

Jan 1, 1991

By R. L. Pariani, R. R. Moskalyk

Justifying refinery material handling equipment jointly involves economics and indirect benefits. The simple evaluation method is applicable when either retrofitting facilities or costing new metal refineries. The text includes points of interest regarding equipment selection as an additional guide. Although the copper industry was used as a basis, it is recognized that similarities in material handling may exist within the parallel electrolytic refining and winning of metals such as copper, nickel, lead, zinc, tin, and cobalt. The analysis of four major automatic systems, typically implemented in many tank houses, includes tabulated data plus a detailed description of additional benefits. General information regarding auxiliary material handling equipment and an overview are included for subject completeness. It is suggested that the quantitative and qualitative aspects presented may contribute to the basis for justification of automated material handling. The labor-oriented economics plus related intangible benefits described herein should provide incentives to modernize or replace manual operations where practical.

Jan 1, 1987

By Jean-Luc Cornet

Downhill, or regenerative conveyors have always been a challenge to the design engineer due to their natural instability under load. The last decade has seen the appearance of high tonnage, high negative lift conveyors with several hundred meters of drop. These conveyors have made necessary the development of new braking systems and intelligent drive controls to address their starting and stopping requirements under various load conditions. This paper describes the critical design criteria of large regenerative conveyors and some of the advances in mechanical braking systems and drive control technology developed by Conveyor Dynamics, Inc. (CDI) to address their specific requirements.

Jan 1, 1993

The Golden Grove Project area is located 220 km (137 miles) east of Geraldton in Western Australia (Fig. 1). The project is a joint venture involving Amax Exploration (Australia) Inc. (Amax), Electrolytic Zinc Co. of Australasia Ltd. (EZ), and Esso Exploration & Production Australia Inc. (Esso), each with 31 116% interest, and Aztec Exploration Pty., Ltd. (Aztec), with a 3 1/2% carried and a 3% contributing interest. The venture covers two significant volcanogenic massive sulfide deposits and some 40 km (25 miles) of highly prospective Archean volcanics. During the course of the past 12 years (to 1983), all four companies were responsible for operating the project at one time or another and all influenced the discoveries. The Gossan Hill and Scuddles deposits are typical examples of volcanogenic massive sulfide deposits associated with Archean explosive submarine acid to intermediate volcanic complexes. They are located in the northwesterly trending Yalgoo greenstone belt of the West Australian Archean Shield. Gossan Hill, located in 1972, is essentially a copper deposit with minor zinc lenses; to date, 97 diamond holes have delineated a geological resource* estimated to contain 13 Mt (14.3 million st) of of 3.4% Cu and 13 g/t (0.38 oz per ton) Ag in the main lenses with minor lenses totaling 2 Mt (2.2 million st) of 3.7% Cu and 17 g/t (0.49 oz per ton) Ag and 1.7 Mt (1.9 million st) grading 1.5% Pb, 14% Zn, and 87 g/t (2.8 oz per ton) Ag. Scuddles is a zinc-copper deposit with gold and silver credits. It *Resource estimate provided by Esso for inclusion in Aztec Exploration Pty. Ltd. 1982 Annual Report was discovered in 1979 and, to the end of 198 1, had been delineated with 42 diamond holes. On the basis of this drilling, a geological resource* of 26 Mt (28.7 million st) has been estimated in three coalescing lenses. The lenses comprise 7.5 Mt (8.3 million st) of 2.1 % Cu, 12 g/t (0.35 oz per ton) Ag, and 0.3 g/t (0.009 oz per ton) Au; 7.6 Mt (8.4 million st) of 0.4% Cu, 9.9% Zn, 73 g/t (2.3 oz per ton) Ag, and 0.7 g/t (0.02 oz per ton) Au; and 1 1.0 Mt (1 2.1 mil lion st) of 1.1 % Cu, 9.3% Zn, 8 1 g/t (2.6 oz per ton) Ag, and 1.5 g/t (0.044 oz per ton) Au. Readers are referred to Frater (1978) and Harris et a). (1982) for a more detailed geological account of these deposits.

Jan 1, 1991

By V. B. Achanti, A. W. Khair

This paper deals with the effects of various bit geometric parameters on the failure characteristics of rock material. Improving the rock-cutting efficiency of continuous mining machines has proven to be an interesting research topic during the last few decades. In the current study, an automated rotary rock-cutting simulator, duplicating a continuous miner, was used to study these parameters in the laboratory. The improvement of bit performance in terms of its life, cutting efficiency, dust production and energy consumption has drawn widespread attention. Research has demonstrated that optimizing bit parameters can result in efficient fragmentation of rock. Indiana limestone rock material was used in this study. The bit tip angle, bit tip size, bit spacing, depth of cut and cutting velocity of the rotary drum were varied to investigate the failure characteristics. The cutting pressure, penetrating pressure and the depth of cut were monitored on the simulator during the cutting process. Airborne dust and settled dust were measured for each experiment. Then, the specific airborne dust and specific energy were determined for each type of bit. Triaxial tests were carried out to correlate the failure angle of the rock in the static case to the dynamic cutting process failure. The physical and mechanical properties of the rock were also determined to assess their influence on the wear characteristics of each bit.

Jan 1, 2000

By J. W. Leonard

A mine's productivity can be significantly increased by using physical and chemical methods to increase the bulk density of newly mined coal. Increases in coal bulk density allows greater amounts of coal to be placed in ships, barges, railroad cars, trucks, shuttle cars and scoops. Increased bulk density can help increase productivity by increasing throughput of container-based, materials-handling systems. Small, easy-to-achieve changes in mining operations are required to obtain the increased productivity. This article deals with chemical methods used to increase coal bulk density. The results and discussion are based on experiments performed in the laboratory. Research at the University of Kentucky using a chemical method shows that an increase of about 15% in bulk density can be achieved using typically small quantities of commercial reagents. This increase in bulk density can produce a proportional increase in the productivity of a mine.

Jan 1, 1992

By Derek M. Hutchinson, Don Zeni

The construction of shafts by blind drilling has been made cost effective by advances in technology and experience. The techniques of blind shaft drilling are discussed and a brief history presented. A recent use of blind shaft drilling to access a small gold ore body in Australia is described. Finally, the most recent developments in drilling machinery are reviewed together with possible applications in new and existing mines.

Jan 1, 1987

By Fathi Habashi

A LARGE number of metals are found in nature, in rich deposits, in the form of sulfides as shown in Table 4.1. Treatment of sulfide ores is done mostly by pyrometallurgical operations; it is only recently that hydrometallurgical processing started to compete with pyrometallurgical methods.

Jan 1, 1970