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By Malcolm J. McPherson

This paper describes the algorithm used in a BASIC program for an IBMXT microcomputer, to simulate the underground mine climate. The program called CLIMSIM has been developed and refined over several years as a result of considerable use at operating mines. The program has been designed to be easy to use and be understood by the practicing mine ventilation engineer. It provides predictions of the work place climate, so that the optimum ventilation/cooling system can be designed to obtain a certain air cooling power or effective temperature at the work place. An example is given of the application of the program to a mechanized cut and fill stope at the Homestake gold mine in South Dakota.

Jan 1, 1986

By L. A. Puchkov

The paper presents the outline of the results in the algorithms and software of the microprocessor-based system for the powerful drugline bucket automatic motion, as well as the technological process control and functional diagnostics of the electrical equipment. The system is, aimed at the increasing both the draglines' working efficiency and the professional, competence of the operators. The excavator-dragline, equipped by the automatized operation, diagnostic and information processing system, possesses considerable technological: flexibility, which can widen therefore its field of application. The tasks of the dragline bucket motion optimal operation, programming of the excavation and overburden dumping processes, as well as the tasks of the control and the analysis of the technological parameters and the diagnostics of electrical equipment conditions, are defined in the paper. In our paper we present the results of these tasks being solved, providing the algorithms of the main mechanisms for the automatic operation for the swinging bucket controlled motion, the algorithms of the statistical analysis of the working efficiency parameters the algorithms of the diagnostics for electrical driving systems. The algorithms of the motion operation are constructed using the predicting dynamic models. The diagnostic algorithms at the normal working conditions form a number of algebraic invariants always equal to Ø with the accuracy up to when the electrical equipment is parametrically adequate. The algorithms of evaluating and analysis of the excavation efficiency make use of the direct measurement and analytical identification. The working condition and quality of the operation and control algorithms are investigated by simulation and natural testing. The results of the mathematical simulation of the bucket motion (with the 20 m3 capacity) of the excavator-dragline with the boom of 90 m in length are given in the paper.

Jan 1, 1992

By PAITIP THIRAVETYAN, KANJANA KUDPENG

The aim of this study is to compare amino acids and organic acids in the extraction of gold from silicate ore. Amino acids were found to have higher efficiency of gold extraction than organic acids at the same acid concentration, which is likely due to amino acids having both carboxylic and amine groups in their structure, while organic acids only have carboxylic groups. Five amino acids (glycine, aspartic acid, glutamic acid, lysine and tryptophan) and seven organic acids (citric, malic, tataric, fumaric, oxalic, succinic and ascorbic acids) were selected to investigate gold extraction efficiency. Aspartic acid was found to have greater capacity to extract gold than succinic acid. The optimal gold to aspartic acid molar ratio was 1:6, and low concentrations of aspartic acid extracted 35 to 42 percent of gold from silicate ore within 15 days. Further studies are needed to increase gold leaching and reduce incubation time. The results imply that aspartic acid can be used as an alternative reagent to traditional methods for extracting gold from ore. This method is nontoxic to humans, is environmentally friendly and can have real applications.

By Larry D. Wayland

Almost 100 sedimentation ponds were conceptually designed for a large surface mining study area in northeast Texas. An approximate procedure was developed to economically estimate construction quantities in order to predict surface water control costs. This procedure utilized site-specific empirical relationships developed from detailed analyses on a representative number of proposed sedimentation ponds. Use of these equations provided earthwork volumes, and spillway pipe lengths. The procedure developed for this study is presented along with the results of a verification analysis.

Jan 1, 1983

By Russell A. Fields

Barite (BaS04) is an industrial mineral with hundreds of uses. It is primarily used as a weighting agent in drilling fluids. This use comprised approximately 97% of U.S. barite consumption in 1981. Barite is found in three types of deposits: bedded, residual, and vein. Bedded deposits, because of their relatively large tonnage, have been the principle target of explorationists. Increased demand for barite in the mid to late seventies prompted many companies to significantly expand their efforts in barite exploration. Barite exploration techniques currently range from outcrop walking and geochemical exploration to gravity and seismic surveys.

Jan 1, 1983

By J. W. III Leonard, T. E. Wilson

In addition to coalbed thickness and basic coal quality data, coal drill cores can produce design data for coal beneficiation processes. To generate design data, a coal drill core should be reduced from its original cylindrical form to a particle size distribution and composition that represents (with the possible exception of top size) a raw coal process stream. Reducing a coal core with a crushing machine rarely accomplishes this representation. This investigation employs drop-shatter impact breakage followed by dry batch tumbling in a steel cylinder rotated about its transverse axis to characterize the core in terms of first-order and zeroth-order break- age rate constants, which are indices of the propensity of the coal to degrade during handling. To reduce composition variables and conserve difficult-to-obtain coal cores, the initial drop-shatter and dry-tumbling tests were done with synthetic cores. Then, cores from three coal beds, Illinois No. 6, Upper Freeport and Pocahontas No. 5, were tested. Comparison of a crushed drill core and a drill core prepared by drop-shatter and tumbling indicated that the size distribution and size fraction composition of the drop-shattered/tumbled core more closely resembled the plant feed.

Jan 1, 2000

By William Gleason

"Mining roots run deep in Glenrock, WY, a town that was founded in part, because of the coal mining that began in the late 1800s. But that rich history also now threatens large parts of the town that were built over the top of the mines. Like many towns in the Western United States, mining is a proud part of the historical fabric and heritage of the town, but the legacy issues from past mining activities continue to present challenges to modern-day engineers.In the case of Glenrock, a small town about 40 km (25 miles) east of Casper, it is flooding from a century of water that has accumulated in the down geologic dip of the furthest northeastern extent of 87 ha (217 acres) of mine workings that has made the town susceptible to sinkholes and other issues (Fig. 1).Full commercial coal mining production began in Glenrock in 1887 during the development of the Fremont, Elkhorn and Missouri Valley railway. Due to poor overlying roof rock and continuous flooding within Glenrock, Mines No. 1 and 2 were fully closed in 1909. During its history, an estimated 87 ha (217 acres) were mined with 50 to 60 percent extraction ratio within the eastern town limits through room-and-pillar mining. It is estimated that the mines produced 22 kt/a (25,000 stpy) during their lifetime. A century later, the water pressure built up in the northeastern most portion of the mine has created serious concerns for residents.In 2016, the Wyoming Department of Environmental Quality’s Abandoned Mine Lands Divisions (AML) investigated a number of subsidence events in the town including sinkholes following heavy precipitation. The AML investigations confirmed that most events were related to the previous mining in the area.Mitigation efforts on the mines were done in the 1980s and 1990s, but the problems in the town and in a nearby subdivision persisted, leading the AML to search for alternative solutions."

Nov 1, 2019

By Sally Gillies

During the 14 years since the last update to National Instrument 43-101 (NI 43-101), there have been many discussions between Canadian regulators and mining companies about mining disclosure deficiencies that arise from regulatory reviews. These discussions are not made public, and as a result, there has been some drift in how NI 43-101 is interpreted by the regulators, which in turn creates uncertainty for the mining companies trying to comply with the instrument. To reduce uncertainty in mining disclosure requirements, the Canadian Securities Administrators (CSA) has issued a notice to update the current NI 43-101 with a streamlined instrument and form. Changes and benefits are listed in the “CSA Notice and Request for Comment — Proposed Repeal and Replacement of National Instrument 43-101 Standards of Disclosure for Mineral Projects,” which is available on the Ontario, Quebec, Alberta and British Columbia Securities Commission websites. The public has been invited to comment, with the comment period ending on Oct. 10, 2025. The 43-101 Companion Policy (43-101 CP) provides an update to the views of the regulators on how the CSA staff interpret and apply certain provisions of the instrument. Collectively, some of the changes to NI 43-101, the form and 43-101 CP are likely to increase the financial and other burdens on the mining companies responsible for the disclosure, and the qualified persons (QPs) who create the disclosure. In other instances, there are missed opportunities to reduce the burden on mining companies and QPs without impacting the markets.

Sep 1, 2025

By D. L. Madge

The text of this chapter was not received in time for printing.

Jan 1, 1979

By W. de Bruijn

Differential reduction and expansion or shrinkage of hematite under the influence of intimately associated foreign oxides may be a source of stress formation and sinter degradation during blast furnace reduction. To study specific effects, synthetically pre-pared hematite powder evenly doped with 1% by weight of several elements present as oxides, was pressed into tablets and sintered at high temperature prior to reduction. Continuous thermo-gravimetric and dilatometric analyses were per-formed on the sintered tablets as these were being subjected to reduction under simulated blast furnace time/temperature/gas composition conditions up to 1183 K. These findings were coupled with observations on the microstructure of tablets removed from various stages of the reduction process.

Jan 1, 1988

By Peter J. Huck, Bruce G. Stegman, Richard E. Thill

Introduction Backfilling of mine voids is used to prevent or control the effects of subsidence on surface structures. The pumped-slurry, blind backfilling process has been successful for stabilizing ground over abandoned and inaccessible underground coal mines. This article describes the systematic evaluation of potential monitoring systems that would improve backfill monitoring technology. It also details field proof-of-concept tests that were conducted on two systems and the difficulties encountered in implementing them. Ground subsidence over abandoned mines can have devastating effects on overlying urban areas decades after the closing of room-and-pillar mines. The result may be cracked foundations, ruptured gas and water lines, broken sewers, distortion or cracking in superstructures, and sinks and potholes in the ground surface. About 32,000 km2 (8 million acres) of land in the US has been undermined for coal. According to the US General Accounting Office, 8,100 km2 (2 million acres) have undergone subsidence and another 8,100 km2 (2 million acres) are expected to subside by the year 2000. Actual figures on land affected or threatened by subsidence are probably much higher, since these estimates were based on late 1960s studies. For more than two decades, the US Bureau of Mines has been engaged in stabilizing ground in urban areas having high risk potential for subsidence costing millions of dollars. Thousands of acres have been stabilized, protecting property worth hundreds of millions of dollars. In earlier years, backfilling was by in-mine stowing in accessible mines or by gravity-feed sluicing methods in inaccessible mines. Pumped-slurry methods have been used extensively in the past 10 years. More slurry can be injected for fill from fewer injection holes over extensive areas in abandoned mines. Since this method requires fewer boreholes, there is less disruption of surface facilities. An investigation was conducted to determine the feasibility of using advanced, remote sensing or monitoring technology for application in monitoring fill placement. Specifically, the objective was to develop conceptual systems for blind backfill monitoring that require fewer boreholes and give better definition than is now possible. Blind Backfilling Methods Blind backfilling operations are conducted from the surface and do not require personnel and equipment underground. These methods are applicable to abandoned, inaccessible workings. Two categories of blind back-filling are point support, practiced by civil engineers to protect individual structures or surface facilities, and areal backfilling methods, used to protect large areas against subsidence. Point Support Methods Point support methods are usually gravity-feed systems. In general, point support methods use small volumes of expensive fill material and require a large number of boreholes within a constructed site. Because of the processed material used for back-filling and the close spacing of the injection boreholes, control and monitoring often may be accomplished by borehole cameras. Areal Backfilling Areal backfilling is conducted mainly by the pumped-slurry injection process (Fig. 1). In eastern and interior coalfields, material used is often mine refuse or flyash, both being undesirable on the surface and costly to dispose of in an environmentally acceptable manner. Hence, the use of

Jan 12, 1983

By BHAMIDIPATI S. SASTRY, SRIVATSAN J. SRIDHARAN, ANMAYA NAIK, ASIF AHMAD, ADITYA PANDEY

Wet kata cooling power (WKCP) measured using a kata thermometer is a well-known heat stress index in mining industries. Although over the years several researchers have proposed different heat indices and indicated the limitations of the kata thermometer, it is still being used in many areas, especially in the South African gold mining industry, mainly because of its simplicity and rapidity of assessment. This paper presents a comparative analysis of the newly developed empirical expression for WKCP, and some of the more prevalent empirical expressions. The analysis presented based on a regression technique aims to assess the disagreement between model predictions and actual measurements. It is found that the WKCP expresses bioclimatic interaction quite well under the specific parameter of interaction that explains the harsh thermal environment and air condition, such as metabolic activity, the person’s clothing, and the velocity of the air in which the person is working. The statistical analysis shows that the WKCP exhibits significant estimates to thermal stress under lower air velocities, light clothing, and higher metabolic activity rates.

By Kerstin Malmqvist

Simulation technique has been used for a feasibility study of a deep exploration project for massive, sulphides in an old mining district, the Skellefte field. An interactive computerized mathematical model of an ore field and a drilling procedure has been constructed. It is possible to represent varying geological structures. The model also takes in consideration economical factors such as drilling costs and ore values. On this model Monte Carlo simulations and probability calculations are done in order to estimate the outcome of different drilling strategies under varying geological assumptions. Under the specific conditions of the well known Skellefte field, it is found to be possible to even calibrate the mathematical model.

Jan 1, 1979

By B. Das, B. K. Mohapatra, K. S. Narasimhan, S. K. Bhaumik

The iron ore slimes (d80 ~ 50 µm) generated at Noamundi iron ore washing plant (TISCO), assaying 57% Fe, 4% Si02 and 8.3% A1203, have been subjected to hydrocyclone studies. The effects of different design and operating parameters have been studied to get a product suitable for subsequent use in the sinter mix. The studies indicate that it is possible to obtain a product containing 64% Fe, 1.4% Si02 and 3.5% A1203 with a recovery of 49% iron. The process involves classification followed by separation in a hydrocyclone. By this method, the overall yield of iron ore production in the plant is expected to increase by 8%. Microscopic examinations and X-ray diffraction studies were conducted to elucidate the mineralogy and liberation characteristics of Noamundi iron ore slimes. This paper deals with the findings of the investigations.

Jan 1, 1993

By T. A. Gray

The environmental liabilities of coal waste disposal sites can have a major impact on a mining project's economic viability. Developing a waste disposal site is no longer simply an exercise in completing paperwork to obtain a permit, with the proliferation of environmental regulations in recent years, managing disposal sites now requires design creativity, short term and long term planning and detailed monitoring to maximize the benefits to the mining company. Operating costs and future capital costs for expansion of existing sites, new site development and regulatory compliance should be reviewed periodically and considered in the overall management plan. This paper discusses various management methods that are being employed in the industry to improve waste disposal operations both environmentally and profitably.

Jan 1, 1994

The effect of the chemical composition of pulverized bituminous coal particles on their physical transformation during the initial stages of combustion has been investigated. The results suggested that cenosphere formation does not require extensive thermal decomposition of the coal particles. The vitrinites in the bituminous coal softened earlier and developed larger cenospheres than the othe macerals. The coal particles swell to a higher extent during combustion than in pyrolysis; however, the cenospheres formed in the former process experienced a higher extent of fragmentation. The development of microporosity occurred predominantly after the resolidification of the swelled char particles. The type of macerals originally in the coal did not significantly affect the microporosity of the chars. Conversely, the morphology and anisotropy of the chars were strongly dependent on the maceral composition of the coal.

Jan 1, 1986

By Harley G. Pyles

Rotary Percussion drilling has shown great improvement over rotary drilling, when hard roof is encountered. In addition, Rotary Percussion drills have eliminated the need for air drills in many applications. Improved drilling rates have been achieved but roof bolting is still a bottleneck in many operations and the demand for further improvement will continue. Drilling rates beyond current performance is limited by the capabilities of existing drill steels and bits to resist increased horsepower input. The most apparent immediate solution to improved drilling is to increase the strength and rigidity of the drill steels. Drilling experience indicates that a l-1/2" diameter or 1-5/8" diameter hole can be drilled as rapidly or 'more rapidly than the standard 1-3/8" diameter hole. Greater torque and thrust capacities can be achieved through the use of larger O. D. and I. D, steels, however, this is only possible if the larger hole sizes can be made allowable. Large diameter anchorage shells can be made available at a slight extra cost.

Jan 1, 1965

By Jiqing Zhang, Jon C. Yingling, Andrzej M. Wala, Richard Ray

The purpose of this paper is to present how Computational Fluid Dynamics (CFD) simulations can be used to study the flow across the main airways of a mine ventilation system. in particular, the flow through the transition zone between the upcast shaft and main fan ductwork was investigated. These studies consider potential design modifications of this transition zone to reduce the energy cost. Although CFD has many advantages, it does not completely eliminate the need for experiments, which are still needed to validate numerical solutions. For this reason, data collected during actual mine tests and CFD simulations are compared in this pa- per. This comparison allows a better understanding of the flow phenomena. Moreover, once the numerical solutions have been validated, CFD can be used with better confidence to predict the effect of changes in ductwork configurations on energy losses. CFD reduces the number and cost of tedious experiments, while enabling a broader scope of design comparisons.

Jan 1, 1997

By Scott E. Broughton, Robert T. Tape

Heap leaching requires containment and storage of cyanide solutions, the volume of which may increase dramatically following an extreme storm event or extended wet periods. This paper describes a computer operated solution storage model developed to assist in the management of these requirements. It results from the accumulative efforts of various Klohn Leonoff engineers working on a number of heap leach projects throughout the western United States for the past several years.

Jan 1, 1988

By Basilio Giurgola, Federico Bonaiuti, Norbert Fuegenschuh

The North East Boundary Tunnel (NEBT) project in Washington, D.C. requires design and construction of several SEM adits which have to be built between lateral shafts and the NEBT-TBM Tunnel. The paper describes ground improvements, the actual excavation, and also the final lining works. Schedule and sequencing restrictions provided some unique challenges which had to be considered when designing and constructing these mostly short, but essential portions of the project

Dec 1, 2022