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By James P. Connell

The Berkeley Pit of The Anaconda Company is located on the southeast slope of the Butte Hill, the legendary "Richest Hill on Earth," and is one of the largest pit operations in the world completely dependent on truck haulage. Through October 31, 1968, the Berkeley stripping and mining operations have moved more than 442,589,000 tons of material. Present scheduled production is at the rate of 260,000 tons per day, with a record quantity of 306,900 tons having been hauled on September 23, 1968. Although the Berkeley Pit has been in production only a little more than ten years, it has been the proving ground for many of the presently used large trucks. Beginning with the original R. G. LeTourneau 75-ton electric truck in 1960, Unit Rig 85- and 100-ton electric drives, Haulpak 65- and 105-ton electric drives, and Caterpillar 100-ton electric drives have all been tested under production conditions. In addition, engine development has kept pace with both 1000-hp diesel and 1100-hp gas turbine engines now under test. As the size of the Berkeley operation has grown, the truck fleet has changed in size and appearance in order to maintain economic mining costs. The original fleet consisted of forty-three 36-ton trucks with conventional mechanical drives. The present fleet is made up of eighty-nine trucks: nineteen 85-ton Unit Rig electrics with 700-hp diesel engines; sixty-nine 100-ton Unit Rig electrics with either 700- or 1000-hp diesel engines; and one 100-ton Unit Rig electric with an 1100-hp gas turbine engine.

Jan 1, 1969

By R. W. Wittkopp

The Relief Canyon gold deposit is located approximately twenty- four kilometers east of the town of Lovelock in Northwestern Nevada. At Relief Canyon, the Late Triassic Grass Valley Formation has been thrust over the Late Triassic Natchez Pass Formation. The lower plate Natchez Pass Formation is composed of massive gray dolomitic limestone which is locally silty and sandy. The upper plate Grass Valley Formation is composed of shale, siltstone, argillite and quartzite. Gold mineralization at Relief Canyon occurs along the highly brecciated thrust contact between these two formations. Weak gold mineralization often occurs above the thrust in the Grass Valley Formation, however, most of the ore grade mineralization is present below the thrust in the brecciated Natchez Pass Formation or where the two formations are mixed as a result of movement along the thrust. Several types of gold mineralization have been recognized at Relief Canyon. A large amount of the ore is present as a jasperoid breccia, however, significant amounts of ore occur as a mixed breccia composed of upper plate rock, fresh limestone, clay and jasperoid breccia. Gold ore also occurs in a fresh limestone breccia which contains a large amount of clay. Below masses of jasperoid, jasperoid stringers containing gold extend into the fresh limestone. Gold mineralization at Relief Canyon appears to be truly disseminated and has the typically associated trace elements of arsenic, antimony, mercury and fluorine. The Relief Canyon deposit can be classified as a structurally controlled disseminated gold deposit. Other deposits that fit this classification are the Pinson and Dee gold mines.

Jan 1, 1984

By D. P. Patil, B. K. Parekh

Water is the mainstay for beneficiation of fine size coal and minerals; however, it is also the least desirable constituent in the final product. The basic concept of the novel process described in this paper is based on the differential surface heat absorption capacity of individual particles, which differs for different species of mineral. When a mixture of fine material is exposed to a radiant energy source, the various solids components present in the mixture will absorb heat energy depending on their composition and there will be difference in the surface temperature of the particles. When this differentially heated solid mixture is placed on a moving belt, which is coated with low temperature melting resin, the hotter component of the mixture will stick to the belt and relatively cooler will stay free on the belt and fall off at the end of the belt run. Experiments were conducted with pyrite, coal and quartz of 6 x18 mesh particle size. The goal of the test program was to find the optimum conditions at which there exists a required temperature difference between minerals and coal particles by controlling the operating and system variables. Preliminary tests results showed that there is a potential for separating mineral matter from coal using the thermo-adhesive separation technique.

Mar 2, 2022

By Robert P. King

In April, 1975 the Colorado School of Mines began monitoring rock mass response associated with a long- wall shield demonstration project near Raton, New Mexico. This project was sponsored by the U. S. Bureau of Mines (DOE) and performed at Kaiser Steel Corporation's York Canyon Mine. Two of the results of the intensive instrumentation effort are the empirical subsidence and horizontal strain models presented herein. These models are based on data gathered during mining three adjacent longwall panels (4N, 5N and 6N). A total of 251 permanent surveying monuments were monitored over the three-panel area. Lines of monuments were oriented along panel centerlines, perpendicular to centerlines and diagonal (45O) to centerlines. Active monuments were monitored twice a week, with less frequent monitoring of stable or slow moving monuments. Primary subsidence monitoring equipment consisted of an AGA Geometer Model 75 and a Wild T-2 Theodolite with -a Wild-Sercel DI-3S distomat.

Jan 1, 1979

By R. M. Wilson

Concentrating plants, in common with other types of industrial plants, cannot operate without lectric power. The elctric distribution system and utilization equipment; therefore, must be carefully considered in all phases of plant design. Two important aspects of proper distribution and usage of electric power are the selection of voltage levels and the methods of system grounding. These are not necessarily the most important design considerations, but are perhaps more controversial than other major points, Modern plants demand increasing amounts of power which, since electric power is the product of voltage and current means higher voltages or currents. Higher voltages require more insulation, higher currents more conductor. The equipment designer?s problem is to obtain in his transformer, cable, switchgear, controller, motor, etc a balance of insulation and conductor to obtain a satisfactory design at lowest cost. To provide the most economical system, both in initial and operating costs requires the system designer to select the proper voltage level. Adequate voltage also permits expansion to meet future requirements, and results in better operation of utilization equipment, Relatively little advancement has been made in recent years in improving conductors; however, great progress has been made in improving insulation. Thus modern plants, in general, now find it more economical to use higher voltages than they did previously. For example plants which only a few years ago would have used 2400 volts as a system voltage often find nowdays that 4160 volts is their proper choice. If the plant requires 10,000 kva br more, then an even higher voltage, such as 13,800 volts, will prove economical. However, for the average concentration plant, with less than 10,000 kva demand, the choice of distribution voltages is between 2400 and 4160 volts, and 480 volts will be used for the low voltage utilization system.

Jan 1, 1958

By Young C. Kim

Because of the tremendous technological advances achieved in recent years in microcomputers, it is not only technically feasible but also economically viable to develop an automatic truck dispatching system using a microcomputer. Such an effort was initiated by the Department of mining and Geological Engineering, University of Arizona in the summer of 1983. Up to date results and experiences prove that today's microcomputers can be economically employed for such a system to be used at small to medium scale open-pit mines. An IBM/XT microcomputer with 10 MB harddisk storage, together with automatic sensing capability of truck movements at several key locations in the pit, formed the core of this system. System software is written primarily in MICROSOFT FORTRAN with supporting subroutines in MACRO assembly language. The software is designed to automatically monitor truck movement throughout the pit, to make heuristic assignments based on expected shovel availability and truck travel times, and to record production statistics. It is currently dimensioned to handle 50 trucks, 10 shovels, 10 dump sites and 3 material types. Due to the lack of funds to purchase the necessary communications hardware, the work related to the automatic sensing of truck movements has not been performed to date. Otherwise, the automatic truck dispatching-system is fully operational on a realtime mode.

Jan 1, 1984

By James O. Glanville

Ice frozen from a dilute chemical solution is mechanically weaker than ice frozen from pure water. This phenomenon is the basis of a practical method for reducing the strength of a mass of frozen coal. If a chemical additive is applied to moist coal, prior to its shipment during freezing weather, the resulting frozen coal can be more easily broken than in the absence of the chemical additive. This greatly expedites the unloading and handling of coal during winter. There has been considerable research into the nature and mechanical strength of ice frozen from various solutions. The literature relating to this process has been reviewed as has the literature relating to the chemical treatment of coal and mineral particulates. Some important articles are discussed and speculations are made about the nature of the ice-weakening process. A laboratory evaluation of the effects of chemical additives on the mechanical strength of ice and frozen coal has been made. An apparatus designed for this purpose is described, and some results obtained with it are discussed.

Jan 1, 1980

By PETER ROBINSON, KEVIN BARBER, OLIVER WHATNALL

Investigation and uptake of filtered tailings continues to grow throughout the globe. This is driven by a wide range of site-specific considerations, which include such factors as tailings characteristics (e.g., amenability to filtration), production rates, climate, water availability, cost drivers, environmental requirements, and social factors. Despite the aforementioned technological growth, the currently available filtration technology is not able to meet the needs of many operations and projects that would otherwise adopt the technology. Experience with large-scale industrial filtration shows that vacuum belt filter systems meet the needs of many modern users, exceptions being the inability to effectively dewater tailings at altitude and/or with a fine particle size distribution: a potential fatal flaw. This paper presents a case study on the utilization of the patented Viper Filtration technology on gold tailings to overcome this challenge and shares the resultant full-scale plant design, highlighting the features designed to overcome cost and scalability deterrents. This technology is a novel mechanical process which complements the vacuum pressure in dewatering the filter cake as it travels along the belt filter. This project commenced with a pilot testing program, which successfully met the objective to rigorously test, measure and record any performance improvements achieved when engaging the Viper technology. Of the two tailings products tested, gross improvements of 4.2%w/w and 5.7%w/w were achieved when compared to the conventional vacuum belt filter operation. This pilot testing facilitated measurement of operating and design data, which forms the basis of the full-scale system design and resultant equipment supply of three vibration roller assemblies for retro-fitting on the existing vacuum belt filter.

Jan 25, 2021

By Volkmar Niemitz

Approximately 30 miles east of Chicago on the southern shores of Lake Michigan stands Bethlehem Steel's newest fully integrated steelmaking facility - the billion dollar Burns Harbor plant. The initial phase of "green field" construction that began in 1963 was directed to the creation of high quality finishing facilities. In late 1964 the 160" plate mill came "on stream" followed closely by Sheet and Tin and Hot Strip facilities. Unit train shipments of slabs primarily from the Lackawanna plant located near Buffalo constituted the input materials for the new mills. In 1967 a hot metal facilities program was announced for Burns Harbor that at its completion would make the plant fully integrated. Incorporated within the program were: 1. A new high performance 50" x 96" slabbing mill complete with a battery of soaking pits. 2. A two vessel Basic Oxygen Furnace Shop. 3. (1) battery of 6 meter high Coke Ovens with attendant coal handling facilities. 4. A 3800 feet long vessel loading & unloading dock. 5. The first conveyor belt fed Blast Furnace in the United States. 6. An extensive materials handling system for receiving, stocking and reclaiming from storage the raw materials for the Blast Furnace and Coke Ovens operation. The intent of this paper is to provide a detailed description of the functions and components of the materials handling system noted above.

Jan 1, 1970

By Ulrich Kappus

The purpose of the project is to divert flood flows of North Potato Creek. The project is located in the southeast corner of Tennessee near Copperhill, approximately 160 kilometers north of Atlanta, Georgia. The project consists of: a 28-meter high dam, a 90-centimeter diameter outlet conduit; an emergency spillway; and a 4.0-meter diameter hard rock trans-basin diversion tunnel. This floodwater management system was part of Cities Service Company mine safety program for the Cherokee orebody which is partially located within the stream channel. The following paper describes the entire project development from feasibility studies to design and construction management.

Jan 1, 1978

By B. Strickland

The decision to accelerate development of Stillwater Mining'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 Praterm J. D.

The process parameters for effective utilization of nitric acid as an oxidant for copper-iron sulfides have been developed. Leaching variables found to be important were acid concentration, temperature, time, atmosphere, pressure, mineral type, particle size, and percent solids. Particular attention was devoted to analysis and control of fumes evolved during the oxidation. Responses recorded were metal extraction, elemental sulfur formation and oxidation, product gas composition and evolution rate, reagent consumption, and residue flotation response. The paper concludes by laboratory testing a flow sheet based on the above observations. Ninety-eight percent of the copper contained in a chalcopyrite-bornite concentrate was recovered, requiring 1. 6 pounds of nitric acid to be regenerated externally per pound of copper extracted. Iron remained in the leach residue as hydrogen jarosite and was ultimately rejected from the system by froth flotation. Sixty percent of the sulfur contained, in the heading concentrate reported in the elemental form; the remainder was oxidized to sulfate and eliminated with the hydrogen jarosite in the flotation tails or by neutralization of the solvent extraction raffinate with lime. Nitrogen was evolved primarily as NO and NO2; up to 3 percent N2O was also present. Gases containing sulfur were absent except when pyrrhotite was solubilized in the absence of soluble copper. In this case, H2S was evolved.

Jan 1, 1972

By A. G. Kim

Increasing transportation costs, clean air regulations and the decreasing availability of landfill space are factors in the increased interest in the utilization of low cost disposal sites for coal combustion residues (CCR). Inactive surface and underground coal mines can satisfy the conditions for stable CCR disposal sites, and subsurface CCR injection can be beneficial in reducing the amount of acid mine drainage (AMD) often produced at such sites. The material is expected to add alkalinity to the subsurface environment and to decrease the permeability and porosity of the buried spoil. Both mechanisms can reduce the amount of acid normally generated at a mine site. The Bureau of Mines is cooperating with an independent coal company in a test of subsurface injection of a mixture of fly ash, from conventional power plants or from fluidized bed combustion (FBC) , with AMD sludge into a reclaimed surface mine. Changes in water quality parameters and the concentration of heavy metals in water samples from wells and seeps are being used to assess the effect of CCR injection. The preliminary results discussed here indicate that improvement in subsurface water quality was related to fly ash injection and that components of the fly ash were stable in the acid environment.

Jan 1, 1994

By L. Galarza

"INTRODUCTION Beneficiation of ores and minerals in a concentrator plant requires a significant amount of water [1] for the grinding and particle separation processes; most of it ends up being recirculated for reuse, slurry pumps are used after crushing and grinding feeding the ore to a classifier to separate fine-grained material (less than 5 mm) from coarse-grained material requiring further grinding. The lower ore grades [2] in the past couple of decades have demanded an increase on power size and efficiency of process machines to maintain a competitive plant throughput; Hydro-cyclone feed pumps to control both under and over milling or grinding are not the exception; Fig. 1 shows a conventional drive train [3] comprising an (1) asynchronous motor (also known as squirrel cage induction motor = SCIM), a high speed coupling (2), a gear reducer (3) and a low speed coupling (4) attached to the shaft of the pump (5), to accommodate the motor rated speed (typically 1800 rpm) to the process requirements (in the range of 250 rpm to 350 rpm), requiring additional components related to the gearbox: instrumentation, maintenance, disposable lubricants and filters, spare parts, thus reduces the overall system efficiency ultimately reflected into CAPEX and OPEX.WHY VARIABLE SPEED DRIVES FOR CYCLONE FEED PUMPS Hydrocyclones or commonly referred as “cyclones” are one of the most important devices in the minerals industry [4]; almost universally used in close-circuit grinding because of their high capacity and relative efficiency, the evolution of Power Electronics made affordable the use of Medium Voltage - Variable Frequency Converters (VFC) for Cyclone Feed pumps in combination with induction motors larger than 500hp (373kW) to gain multiple benefits: - Soft start with minimum electrical utility disturbance = inrush current mitigation - Full Torque available at zero speed for overload startup with pulp solidification after long still stand periods, superior to any other reduced voltage starting method. - Optimum and constant pump speed (independent of the electrical network or load condition), compared to across the line SCIM operation - Flexible Motor Voltage and Speed regardless of the power distribution Voltage and Frequency - Improved Power Factor (close to unitary), over the entire operating speed range"

Jan 1, 2015

By H. F. Haller

Large volume sand plugs are placed in tunnels to stem underground explosions at the Atomic Energy Commision's Nevada Test Site. Placement through long, narrow accessways is like stemming coyote holes and blast chambers in mining and construction. Experience with several other methods showed that pipeline conveying could be preferable. Small scale tests justified predicting a placement rate of 20 y. p. h. at 1000 feet, with a modified gunite placer. The initial production trial placed over 2000 c. y. and was estimated to effect a small cost saving after paying for new equipment. Initial problems included duct replacement and supply delays, dust, and other personnel hazards. Operations analysis and SOP'S reduced delays during the second field trial, minimized hazards, doubled production. Re cent re search and operations analyses produced data on abrasion resistant ducts, identified minor equipment modifications which can improve production, developed techniques for impact compaction to 90% ?maximum? and for extension of the practical range to 2000 feet. Twenty-two illustrations include an air consumption-distance chart.

Jan 1, 1967

By Ihor Kunasz

The high lithium demand forecasted for some high tech applications and batteries for electric and hybrid-electric vehicles, in particular, has sparked increased exploration for lithium, particularly for lithium- and potassium-bearing brine deposits. The latter have generally followed the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) NI 43-101 guidelines on resource reporting, formulated for hard rock deposits (metals and industrial minerals). While a number of the requirements can be appropriately applied to brines, brines are fluids and require a specific analysis leading to a distinct set of reporting requirements. Brines cannot be considered industrial minerals because the various elements occur as ions in a dynamic fluid, rather than being chemically bonded in a solid. Although chemicals are produced from brines, brines have no relation to industrial mineral deposits. This article analyzes the recently released (Nov. 1, 2012) document CIM Best Practice Guidelines for Resource and Reserve Estimation for Lithium Brines, in light of the practical knowledge available from existing brine operations. It recommends modifications to the guidelines, which, if applied in their present format, will result in overstating resources and reserves and mislead potential investors. The CIM Best Practice Guidelines for Resource and Reserve Estimation for Lithium Brines document is generally descriptive and does not fully address the methodology for brine resource or reserve definition. Lithium and other elements (potassium, magnesium) are contained in a fluid, the hydrologic characterization of which should be the principal focus of a brine exploration program. The fundamental requirement in defining lithium brine resources and reserves in a salar is the identification and definition of those formations ? the aquifers ? that will yield brine in a usable quantity to a well, because brines can only be extracted by pumping wells. Fine-grained sediments will never, as required in the summary Table 1, have ?reasonable prospects of economic extraction,? cannot be considered and, therefore, need not be tested. However, the guidelines recommend the collection of solid samples and a high-core recovery for laboratory testing of various sediments instead of focusing on the brine.

Oct 1, 2013

By Drew Bazil, David Smith, Matteo Ferrucci, David Pittman

The Gateway program will provide additional rail capacity between New Jersey and Manhattan. This paper describes how a 70-foot-deep section of cut and cover tunnel was designed to directly support future high-rise towers. The tunnel will link previously completed tunnel sections under Hudson Yards to future tunnels under the Hudson River. The design aims to minimize constraints on future overbuild and future tunnels, while maximizing constructability within a small worksite. The tunnel will pass under the High Line elevated walkway, next to an active rail yard, and close to a subway tunnel. The design was developed by a tri-venture of WSP, STV and AECOM. WSP led the design of major underground works; STV designed utility relocations and the underpinning concept for the High Line; and AECOM designed temporary in-tunnel systems. Construction is expected to start in 2023.

Jun 13, 2023

By Surendra K. Mishra

With increasing regulatory pressure from the environmental authorities, waste management has become a focal point of industrial operation. To offset the waste management costs, industry has made conscious effort to recover usable resources from the waste streams. This paper reviews the technical developments and current practices in processing of waste materials. Methods for recovering metallic, non-metallic and organic species from solid wastes and effluents generated by operating plants are discussed.

Jan 1, 1997

By Xiyu Gao, Yi Yang, Mark I. Pownceby, Shuiping Zhong, Miao Chen

In the present study, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray absorption near edge structure (XANES) spectroscopy, and Raman spectroscopy were used to investigate the effect of chloride ions on chalcopyrite bioleaching and chemical leaching at 25 °C. The leaching results show that the addition of chloride ions suppressed the dissolution of chalcopyrite in both chemical and bacterial leaching. In chemical leaching, the solution redox potential in the experiment without Cl− stayed in a range more suitable for chalcopyrite dissolution compared with experiments with Cl− . In bioleaching, the bacteria activity was suppressed by Cl− leading to low dissolution rates of Cu. Surface morphology and chemical speciation studies confirmed the formation of potassium jarosite on the surface of the chalcopyrite leach residues. In addition, S K-edge XANES indicated the formation of trace amount of elemental sulfur and covellite on the mineral surfaces.

By Leena Suopajärvi, Karin Käär, Marcin Szumny, Jari Joutsenvaara, Md Ariful Islam, Helmut Mischo, Georg Meissner, Ossi Kotavaara, Catalina Vrabie

This study outlines implemented tactics and results for community empowerment through participation in questionnaire surveys, educational programs, and discussion on sustainable sourcing from new critical raw materials (CRMs) projects. Utilising questionnaire surveys, including the Public Participation Geographic Information System (PPGIS), the research gathered public opinions from Estonia, Germany, Poland, and Zambia, receiving 1,068 responses. These responses addressed various social, economic, and environmental issues related to CRM projects. Feedback from educational courses with participants from over 25 nations and public events provided additional insights. The collected data and feedback offer crucial input for advancing sustainable and responsible CRM sourcing strategies in these regions.

Feb 1, 2025