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At the dawn of the computer age in the early 1950's, few people in either the minerals industry or the field of electronic data processing (EDP) would have predicted the tremendous impact that the computer has had on the way we conduct our everyday lives and businesses. Herman Hollerith himself (see next page), the Columbia University mining engineer 'turned statistician who developed the first punched card electronic tabulating machines for the US Census Office in the late 1880's, would doubt- less be amazed at the progress that has been made in the application of data processing techniques to nearly all aspects of the mining cycle (Aul, 1974). More than any other factor, the availability of economical computing equipment has led the way for the development of the broad range of mining computer methods described in this text. While limits have been identified for many of the technologies commonly in use today, new technological advancements point to continued exponential advancements in computing price-performance in the 1980's. With those advancements, we may look forward to continued expansion of the role computers will play in mineral production.

Jan 1, 1979

By Robert F. Hauck

This chapter discusses a new technology for computer control in open-pit mine operations: the real time automatic dispatching of manually driven trucks to shovels. The monitoring of truck activity is accomplished by detection of local radio signals. Computer-operated directives are communicated to drivers by remote controlled digital display units inside the truck cab. The production objective is to maximize tonnage in a cost effective manner. The problem is formulated in the appendix and the solution method is briefly described. Side conditions such as maintaining delivered ore grade aims, balancing waste to ore volumes to keep within stripping ratio tolerances, and meeting production rate requirements temporarily established for certain shovels are also discussed. Experience with a developed event- to-event simulator applied to analyses of several North American mining operations using this technique is summarized. Complete systems employing this technology are now under- going installation at mine sites in Canada and the United States.

Jan 1, 1979

By S. Page, R. Bhaskar

The development is described of a real-time tracer gas sensing system for use in fell-scale laboratory studies of air flow behavior around mining machines. A semiconductor sintered tin-dioxide gas sensor is used for gas analyses. A data acquisition and analyses software specific to the sensor characteristics was also developed as part of the system. The system permits the study of transient behavior and assists in obtaining a better understanding of the movement of air around mining machines and in the study of the effect of potential airflow modification devices on the dust exposure of face personnel. It seeks to replace the current method of using a centralized infrared gas analyzer that polls several sampling points using an array of solenoid valves and gas line purgers. The polling results in a significant time lapse between the first and the last set of readings. The system described in this paper has the advantages of real-time sampling and safe operation.

Jan 1, 1992

By Adolf J. Jonaitis

Outokumpu developed TankCell flotation cell technology beginning in 1990, following 35 years of successful flotation cell experience and application. In 1994, Outokumpu proved favorable operating success of 100-m3 (3,500-ft3) TankCells for porphyry copper and zinc flotation. In 1995, evaluation of a 150-m3 TankCell led to the successful application of these large cells in several operations. More than 350 TankCells of 100 m3 and larger in volume have been installed and are in operation. Key features of the Outokumpu TankCell design will be described. In addition, discussion of operating data from various metallic mineral flotation operations worldwide will be presented. Large flotation cell development continues today, with operating cell volumes of up to 160 m3 (5,500 ft3) in operation.

Jan 1, 1999

By Rodger E. Denison

The Middle Ordovician Simpson Group in the Arbuckle Mountains of southern Oklahoma contains sandstones of unusual purity. These have been exploited as glass sands since 1913 (Ham, 1945). Where quarried, the sandstones are uncemented or weakly cemented, greatly facilitating mining and processing. The origin: sedimentary setting, and lack of cementation of these valuable sands has been the source of much discussion. The lowest of the sandstone units in the Simpson is at the base of the Oil Creek Formation. The basal Oil Creek sandstone is exposed in a series of accessible quarries north of the town of Mill Creek in Johnston County. Virtually all conclusions and generalizations concerning origin of the Simpson sandstones are based upon observations made in these quarries. The three Simpson sandstones overlying the Oil Creek share many of the same distinctive qualities, and there is an assumption that they share a common origin.

Jan 1, 1999

By Jan W. Oberholzer, Jan J. L. Du Plessis, Gerard Appelman, Andrzej M. Wala

The use of on-board scrubbers on continuous miners is an important aspect in efforts to reduce the amount of dust that heading workers are exposed to. As part of the CSIR:Mining Technology's research programme to combat dust, a collaborative project with the University of Pretoria was conducted to evaluate scrubbers. Based on fundamental parameters that were identified to play a role in determining the efficiency of scrubbers, a protocol for testing scrubbers in the laboratory environment, as well as the working section, was established. Tests on various prototype scrubbers were conducted in the laboratory environment. These tests proved some of the fundamental premises according to which scrubbers were designed. By testing some of the newer scrubber types underground, insight into the effect of alternative design aspects on scrubber efficiencies was obtained. The importance of the factors which play a role in reducing the amount of dust in the air is illustrated, as well as the role which other non-design factors play in the reduction of dust levels.

Jan 1, 1995

By W. K. Utt, C. C. Woodward, W. L. Howie, G. G. Miller

The process of roof drilling and bolting is one of the most dangerous jobs in underground mining. In the United States, roof drilling and bolting results in about 1,000 accidents with injuries each year. Researchers, from the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are studying the feasibility of using a drill-monitoring system to estimate the strength of successive layers of rock and assess the integrity of a mine roof. Such a system would allow roof drill operators to be warned when a weak layer is being drilled. Using measurements taken during drilling, a neural network can classify mine roof strata in terms of relative strength. The concept has been proven in principle. This research project was undertaken to increase the safety of underground miners, especially those involved in roof bolting. The system should be applicable to the mobile drills now used in underground mines, and the system would likely find wider application as well.

Jan 1, 2003

By Milton E. Wadsworth, M. Ken Han

The kinetics of leaching of galena in hydrochloric acid solutions with sulfur dioxide gas have been investigated experimentally. The leaching method is then applied to complex sulfide concentrates to evaluate its selective leaching capability and to develop a new hydrometallurgical lead extraction process based upon the method. The leaching reaction follows a linear rate with an activation energy of 61.9,KJ/mole. The rate Is of first order with respect to the product [H+] [Cl-] . Excel lent selective leaching capability f s demonstrated and an attractive hydrometallurgical process flow sheet is proposed.

Jan 1, 1989

By Bela Koman

Abstract - A shiploading terminal near Punta Arenas, the southernmost city of the world (lat. 53°-10'S, long. 70°-54' W) is described. Strong winds, choppy seas, frequent gales, rain, and snow make it difficult to load ships at an offshore berth in this area. Detailed site investigations, including a wind-recording program, supplied sufficient information for the analysis of operating conditions. The weather pattern of the entire region, including the predictability of gales, was utilized in the analysis. The results showed that a bulk loading terminal at this location is feasible, provided that the design takes into consideration the specific problems of the site. The final layout shows a terminal that can be approached from several different directions, depending on the direction of the wind. The mooring system is arranged to allow alter- native ways of attaching and casting off mooring lines and executing docking and departing maneuvers. The berth is supported on piles and contains the minimum of structures, relying on a slewing shiploader to reach the ship in any position, with only limited fore and aft shifting of the vessel for loading the extreme hatches. Results of wind recording, statistical analysis of wind and wave data, operating criteria, and the results of berth availability analysis are included in the paper.

Jan 1, 1987

By M. A. Trevits, R. J. Matetic

Mining operations have long been accused of causing a disruption to local, domestic and agricultural water supplies. More recently, concern for water supplies has increased with the advent of high-extraction mining techniques, namely longwall mining. Theoretically, any water-bearing zone in the overburden above a high-extraction mining operation may be affected by mining. In some cases, a confining bed may be fractured causing a loss of water to a particular zone. In other cases, increased fracture permeability may enhance the ability of an aquifer to transmit and deliver water. Unfortunately, only a limited number of studies have been conducted that characterize hydrologic changes and also quantify the magnitude of mining-induced subsidence. The US Bureau of Mines (USBM) conducted such a study at a mine site in Greene County, PA. A total of eight water wells were drilled, and hydrologic parameters, such as specific capacity, transmissivity and well yield, were determined both before and after mining. Electronic water-level recorders were installed on each water well to provide continuous observations of water level fluctuations.

Jan 1, 1993

By Kenneth N. Han, Xinghui Meng, A. J. Monhemius, G. W. Warren, E. Peters

The leaching of gold in ammoniacal solutions containing various oxidants in an autoclave has been investigated. Also studied are thermodynamic and kinetic aspects of the ammonia leaching of gold and silver. The variables studied included stirring speed, temperature, concentration of ammonia, ammonium, and various anions. Arrhenius activation energy values were found to be between 47.1 kJ/mol and 86.2 kJ/mol depending upon the kinds of oxidants used. An electrochemical reaction controlling mechanism has been proposed for the dissolution reaction. The leaching behavior of gold and silver from various ores in ammoniacal solutions containing various oxidants has also been investigated. The samples tested included sulfidic as well as carbonaceous refractory ores. The recoveries of gold and silver from these refractory ores were better than 96% within 2-3 hours of leaching time.

Jan 1, 1993

By J. M. Kruger

High-resolution ground-penetrating radar (GPR) was used to image the near-surface extent of two exposed Late Cretaceous kimberlites intruded into lower Permian limestone and dolomite host rocks in northeast Kansas. Six parallel GPR profiles identify the margin of the Randolph 1 kimberlite by the up-bending and termination of limestone reflectors. Five radially-intersecting GPR profiles identify the elliptical margin of the Randolph 2 kimberlite by the termination of dolomite reflectors near or below the kimberlite's mushroom-shaped cap. These results suggest GPR may augment magnetic methods for the delineation of kimberlites or other forceful intrusions in a layered host rock where thick, conductive soil or shale is not present at the surface.

Jan 1, 1997

By L. B. Hales

The advent of the process control computer with its capabilities of monitoring, storage, and real-time control has revolutionized control technology in the mineral industry. Initial efforts to introduce the computer into process control began in the early 1960's. However, it wasn't until the last decade with the introduction of integrated circuits and minicomputers that truly successful applications became visible. Computer hardware and real-time operating software have improved to the point that they rarely provide major problems in the implementation of successful control systems. At this time the most prevalent problems and obstacles affecting the successful implementation of a control system are as follows: (1) reliable and representative sampling systems; (2) rugged and reliable process sensors; (3) the availability of well-defined control strategies; (4) the willingness of plant management to provide the continuous support necessary to acquire and/or train appropriate personnel in the operation and maintenance of advanced control systems. Discussion of these problems and of the instrumentation required for the successful application of computers in minerals processing plants follows. In order to enhance this discussion the remainder of this subsection is broken up into individual mineral processing categories.

Jan 1, 1979

By Ernest Peters, Fiona M. Doyle

The leaching and bulk decomposition of sulfide minerals is of enormous commercial importance in several areas of the minerals industry. These include: direct leaching of ores or concentrates for the recovery of the contained metal values; decomposition of sulfides to recover associated values such as encapsulated gold; and the potentially hazardous oxidation of sulfides in waste disposal facilities. A significant challenge to successful future developments in these areas is to improve our fundamental understanding of the mechanisms of the chemical, electrochemical, and bacterially-mediated interactions between sulfides and aqueous solutions. The paper summarizes current understanding of these mechanisms, and discusses promising new directions for research.

Jan 1, 1989

By Mahesh C. Jha, Frank J. Smit

Column flotation and selective agglomeration are promising advanced physical cleaning processes that can be developed for preparing premium quality coal-water slurry fuel from coal fines. Such a fuel could either replace oil or natural gas in certain industrial and utility boilers or else could be burned in advanced combustors currently under development. These applications require coal cleaned to sulfur and ash contents below 258 g/GJ and 430 - 860 g/GJ (0.6 lb/million Btu and 1 - 2 lb/million Btu), respectively, to meet clean air emission requirements. A highly loaded slurry must be produced in order to avoid derating the boilers, and the total cost of the fuel must be below $2.37/GJ ($2.50/million Btu) in order to penetrate the market by the turn of the century. Achieving these technical and economic goals depend critically on the selection of suitable feed coals. This paper describes the identification and evaluation of 18 coals and final selection of six coals from different regions of the United States as potential feedstock for preparation of premium fuel. The work is being performed under a cost-shared DOE project.

Jan 1, 1995

By B. J. Arnold, F. F. Aplan

Prior laboratory work has demonstrated that much of the fine ash forming minerals entering a flotation froth are there as a result of water carryover- from the bulk contents of the flotation cell (Arnold and Aplan, 1986a). Using a bank of four 8.5 m3 (300 cu ft) Wemco flotation cells cleaning a well-liberated Lower Kittanning seam coal, test results show that the sulfur and ash content of the froth is directly related to the water content of the froth (or inversely related to the percent solids in the froth). Reagent changes that result in a watery froth produce a higher ash content in the froth. A direct comparison of laboratory and plant results show that the standard laboratory flotation test produces a product higher in sulfur and ash than that produced in the plant. Caution should be exercised when extrapolating laboratory test results to the plant situation. A method of estimating coal flotation product quality in the plant based on laboratory tests is given.

Jan 1, 1991

By Th. Petropulos

The Zn-Ag-Pb mineralization zone near Molai (Greece) was explored by more, than 60 drillholes. Promising results led to the decision of additional drillholes in order to confirm the expected spatial extension of the deposit. A multiobjective approach is described which optimizes the location of a set of 5 additional drillholes. The decision is based on estimation errors for grade, thickness and depth of the main ore bearing layer, with respect to cut-off values for grade and thickness. The linear combination of these variables defines a favorability index which is used for mapping optimal drillhole locations. The map shows several clusters of favorable cells. A declustrering algorithm is used to select a representative cell for drilling in each cluster.

Jan 1, 1989

By Gilles A. Tremblay

Acidic drainage has been long recognized to be the largest environmental liability facing the Canadian mining industry and to a lesser extent the public through abandoned mines. The Mine Environment Neutral Drainage (MEND) Program was the first initiative formed in 1989 to develop scientifically-based technologies to combat acidic drainage. This 9-year volunteer program reduced the liability by several hundreds of million dollars and established Canada as the recognized leader in research and development on acidic drainage for metal mines. MEND 2000 is a three-year program that started in 1998. The key to MEND 2000 is technology transfer- providing state-of-the-art information and technology developments to users. MEND-developed technologies are being verified by long-term monitoring of large-scale field tests. Maintaining linkages with a number of foreign government and industry-driven programs is also important to the successful completion of the program. Through these efforts a further reduction of the environmental liability associated with acidic drainage will be realized.

Jan 1, 2000

By T. Leftwich, G. Faison, K. Pavlich, R. Borden, S. Pavlou

Recent regulatory and policy initiatives under the Resource Conservation and Recovery Act (RCRA), and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), will have a significant effect in risk reduction requirements for the mining and minerals processing industry. For example, Congress is considering regulating 20 special wastes from the processing of ore and minerals through RCRA Subtitle D and TSCA. The performance of risk analyses and environmental planning at mining projects is often driven by Federal and state regulatory standards. Recent regulatory and policy initiatives by the Environmental Protection Agency under the Resource Conservation and Recovery Act (RCRA), and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), will have a significant effect on environmental planning and risk reduction programs for mining and minerals processing. Regulatory programs implemented under other Federal laws including the Safe Drinking Water Act, Clean Water Act, and Clean Air Act will also impact industry practices. This paper provides: 1) a brief overview of mining waste and mining waste management, and 2) a description of these regulatory initiatives and a discussion on the impacts of new requirements on environmental and risk reduction programs in the mining industry.

Jan 1, 1992

By J. E. Hoffman, Massimo Maccagni, T. J. Keefe, Marco Olper, O&apos

The problem relating to the use of insoluble anodes in acidic and highly aggressive environments has still not been definitely solved, and it is therefore a recurring subject of discussion. The fields of application in which insoluble anodes play a fundamental role are mainly in the electrolytic extraction of metals, in cathodic protection with impressed current, and in the production of oxidized halogenated salts. Based on the foregoing, B.U.S Engitec Servizi Ambientali (BESA) developed an electrode suitable for the use in the above-mentioned system. The basic component of the BESA anode is a bimetallic wire made of a copper rod (core) covered by a thin layer of valve metal, to be chosen between tantalum (Ta) and niobium (Nb). The wires, coated with suitable catalyst (PbO2, Pt or others) are inserted in a plastic frame and fixed to a current feeder by means of a screw, ensuring an optimal contact. Experimental data on the operating conditions, such as kind of electrolyte, current density, electrode potential, corrosion tests and fields of possible application, are described.

Jan 1, 1993