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By D. A. Dahlstrom

Energy costs have had a serious impact on all basic industries today. This is due to the significant amount of energy that is used to convert natural resources into usable products. Other factors such as transportation with its major energy requirement and materials employed in processing that have already required significant energy input for their manufacture accordingly influence delivered cost to the user. The farmer is a good example of this. While his large capital investment for land, machines, and buildings is highly impacted by today's interest rates, his chemical fertilizer, herbicides, and pesticides as well as those same machines and transportation costs for his products have also been seriously affected by energy costs. With the many unit operations involved in mining and mineral processing, several of which require significant inputs of energy, one can only conclude that this industry has experienced a great increase in percentage of total cost for energy alone. Fuerstenau (1975) indicated that the minerals industry used about 12.5% of the total energy produced in the US. McNulty (1983) listed the total energy requirements for the production of 0.9 t (1 st) of various metals including the energy consumed in the manufacture of supplies employed, such as tires, explosives, chemicals, grinding media, etc. (Table 1).

Jan 1, 1987

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 John G. Reid

Geologists, employed by the Australian Company, Metals Exploration Limited, discovered nickel laterite enrichment at Greenvale in 1967. A joint venture was arranged with the Freeport Minerals Company who had gained early experience with nickel laterite ores when building and operating the Nicaro and Moa Bay Treatment Plants in Cuba. A 5 tonne/day Pilot Plant at the Freeport research facilities at Belle Chasse, Louisiana, verified the amenability of the ore to treatment by the reduction and ammonia-ammonium carbonate leaching process used at Nicaro. A 5 800 tonne/day Treatment Plant was constructed on the coast at Yabulu, North Queensland. This paper describes the ore body, the mining operation and the stages of treatment required to produce nickel oxide products and a mixed nickel/cobalt sulphide product at Yabulu.

Jan 1, 1979

By J. A. King, D. R. Weir, P. C. Robinson

Preconcentration of Porgera ore results in high recoveries of gold into gravity and flotation concentrates. The bulk of the gold is contained in auriferous pyrite flotation concentrate and is not readily recoverable by direct cyanidation. Oxidation in autoclaves at high pressure and temperature produces a residue that contains the gold in recoverable form. Pilot plant treatment of the autoclave residue is described, through washing and jarosite decomposition stages, to cyanide leaching and recovery of gold and silver by carbon-in-pulp techniques. The concern associated with disposal of plant effluents are also addressed.

Jan 1, 1987

By William H. Schiffbauer

Research is being conducted toward making underground mining equipment autonomous. This will facilitate improvements in safety by relieving workers of dangerous tasks and will increase production by providing more accurate control with less down time.. A Bureau of Mines developed microcomputer network has enhanced this research by permitting a group of diverse computers to interact with a mining machine as well as with each other over a common data link. The network is composed of specially integrated off-the-shelf hardware and industry-standard operating system and programming languages. Using the network, researchers can conduct various experiments with the mining machine using a diverse group of intelligent sensors, computers, and microcontrollers. Descriptions of the mining machine, the mining machine control computer, control algorithms, -the microcomputer network architecture, and communication protocols are discussed.

Jan 1, 1989

By David G. Laughton, Richard Poulin, Michael R. Samis

Real options (RO) valuation is an alternative net present value (NPV) framework that is able to incorporate both management flexibility and dynamic project risks. In this paper, management is considering the development of a satellite low-grade zone while operations in a developed high-grade zone continue. If the low-grade zone is developed prior to high-grade zone exhaustion, mine capacity must be expanded before additional production from the low-grade zone can be processed. This expansion can be avoided only if low-grade zone development is delayed until the high-grade zone is exhausted. The RO model presented here allows the development and capacity expansion decisions to be reconsidered on a discrete half-year basis. It delineates price regions, for given levels of high-grade zone reserves, in which it is optimal to develop the low-grade zone, defer low-grade zone development and abandon the mine irrevocably.

Jan 1, 2002

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 Kalliat T. Valsaraj, Louis J. Thibodeaux

A mathematical model is described for the transfer of hydrophobic compounds from aqueous to an immiscible organic phase using fine bubble aeration; the process otherwise known as "solvent sublation" an adsorptive bubble separation process. The limitations of the model are explored by simulating experimental results both for a batch scale process and a continuous process. The qualitative predictions of the model with respect to the influence of the organic layer (mineral oil) are tested by performing experiments using chloroform and 2,3,6-trichloroanisole as hydrophobic compounds in the aqueous phase. The continuous process is seen to be limited by the requirements of fine bubble generation and the ratio of influent feed rate to air flow rate.

Jan 1, 1989

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 E. J. Donovan, O&apos

The use of Dynamic Analysis techniques in the design of conveyor systems is extremely limited. The most frequent use of the technique is in large and expensive systems where the emphasis is on insurance against failure caused by catastrophic tension waves. This paper sets out to illustrate a much wider range of applications where dynamic analysis has been successfully employed. The examples chosen deal with identification and correction of dynamic low tension problems, the variability in take-up movement as other system parameters change, the requirement for proper tuning of starting controls and finally the absolute necessity for a complete understanding of the entire system when specifying brakes for critical applications. The intent of the paper is to get designers to view a conveyor as a system of interacting flexible components rather than as a single rigid body.

Jan 1, 1993

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 SAMUEL A. LOLON, ADITYA JUGANDA, JURGEN F. BRUNE, JR. GREGORY E. BOGIN

Historically, there have been many events of mine fires and explosions recorded in the United States and other countries that have demonstrated the existence of explosive methane-air mixtures, herein referred to as explosive gas zones (EGZs) [1]. The risk of mine explosions can increase if these EGZs migrate out from the gob into the surrounding mine entries — a phenomenon known as gob breathing. A number of 3D computational fluid dynamics (CFD) simulations using various magnitudes and periods of barometric pressure variation have indicated that the EGZ outgassing potentially occurs due to lags in pressure, which are strongly influenced by mine conditions and ventilation systems. Early-warning systems with real-time pressure monitoring and the application of gob ventilation boreholes are recommended to detect and mitigate explosion hazards from gob outgassing.

By S. Eugene Sankey, Geoffrey L. Payne

Modern metallurgical processing often depends heavily on the use of flocculants to achieve the high levels of efficiency required. Selection of the optimum polymer can be complicated by the effects of process streams on the chemical and physical stability of the chosen polymer. Similarly, the presence of the polymer can have positive or negative side effects on process streams, such as phase disengagement in solvent extraction, foaming at filters and thickeners, crystal growth modification or flotation performance. Guidelines are given to highlight areas where problems may occur and suggestions made as to how these can be overcome. Practical advice on the preparation and application of polymers in process liquors is provided.

Jan 1, 1986

By V. Kontogianni

The underground extraction of coal is associated with ground movements extending from the mining area to the ground surface, which result in bowls of ground subsidence, with amplitude exceeding the amount of several meters and occasionally with important tilt and curvature of ground surface. Such changes at both the underground environment and surface topography lead to destruction of buildings, failure of utilities and transportation networks, and occasionally formation of areas vulnerable to flooding, or even small pools. Based on geodetic surface measurements of ground elevation changes, various theories and empirical models relating surface subsidence with the geometry of underground voids formed have been proposed, and predictions of expected subsidence in the form of contours have been estimated. In this study a case study of planning of a new highway network through areas in which coal extraction was also planned is discussed. This work is partly funded by EU. The optimum solution selected was a modification of the initial highway planning, so that the road is increased in length and by-passes the richest coal-field, where maximum post-exploitation subsidence was predicted, and only crosses either minor coalfields, which are not to be exploited, or even margins of main coalfields, in which minor post-exploitation subsidence is expected.

Jan 1, 2006

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 Martin L. Smith

Mine waste characterization and risk assessment currently focesses on water quality and largely ignores boththe charteristics of the wastes themselves and how wastes interact with the environment. Characterization of the parameters that control contamination of pore waters and their migration can quantitatively assess risk and remediation strategies in terms of cost effectiveness and risk reduction. Since mine waste characteristics are spatial, geostatistical methods should be used for characterization and assessment. A number of geostatistical methods are reviewed in terms of their application to mine waste sampling, modeling and risk assessment and management.

Jan 1, 1995