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By D. W. Scott, D. G. Minnes

Introduction Ontario's diverse industrial mineral resource base includes structural minerals such as sand and gravel, crushed stone, building stone, clay, shale, limestone, and dolostone. These resources are used to produce aggregates, brick, metallurgical stone, fillers, cement, lime, and other construction materials. The majority of the operations are in deposits of Palezoic and Quaternary age in southern Ontario, close to the major markets. Province-wide, there were more than 140 Mt (154 million st) of aggregates produced in 1985. About 115 Mt (128 million st) of that was produced in southern Ontario with the rest being largely from Crown land in northern Ontario. Structural industrial minerals account for more than 80% of the value of total industrial mineral production. The remaining 20% is accounted for by the nonstructural minerals, such as salt, which is produced in the southwestern part of the province. A host of other nonstructural industrial minerals are known. Production, though, is currently restricted to calcite, gypsum, quartz, talc, nepheline syenite, and byproduct metallurgical sulfur products (Fig. 1). Major production is close to the large markets of urbanized southern Ontario and the northeastern and northcentral US. With an abundant variety of industrial mineral resources and the large population within 650 km (400 miles) of most deposits, the market offers great potential. Ontario's nine million people accounted for about 35% of Canada's entire $476.3 billion gross domestic product in 1985. This equates to about one-third of the nation's buying power being within a 200-km (125-mile) radius of Toronto. This major concentration of industrial and economic activity has resulted in a well-developed industrial minerals industry that fulfills most of the structural industrial minerals demand in Ontario. Nonstructural industrial minerals are similarly well placed to compete in this high demand area. Although Ontario manufacturers still import some of these materials, Ontario products are achieving significant market share. And, they serve the needs of neighboring provinces and states. Present production and trends Ontario has traditionally produced significant amounts of industrial minerals. This produc¬tion had a value of $956 million in 1984 (Table 1). Structural materials production in 1985 and 1986 approached or exceeded levels not seen since the early 1970s. Many new products have been developed using these raw materials. The industry is becoming concentrated in the hands of several large companies, mainly four large cement com-

Jan 12, 1987

By E. Watkins, V. Gangrade, P. Zhang, J. Addis, D. W. H. Su, T. Minoski, C. Hollerich, M. Van Dyke, S. Schatzel, H. Dougherty

"This paper presents the results of a comprehensive study conducted by the Centers for Disease Control (CDC), National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Mining Research Division (PMRD) to evaluate the effects of longwall-induced subsurface deformations and permeability changes on shale gas well integrity and safety under shallow cover. NIOSH researchers selected a study site over a southwestern Pennsylvania coal mine, which extracts 1,500-ft-wide longwall faces under 482 feet of cover. One in-place inclinometer well and three permeability monitoring wells were drilled and installed over a 125-ft by 275-ft centers abutment pillar. In addition to the inclinometer well and monitoring wells, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the first 1,500-ft-wide longwall panel on the south side of the abutment pillar mined by the site.A number of FLAC3D finite difference simulations (Itasca Consulting, 2017) were conducted to estimate surface subsidence, coal pillar pressure increases, and horizontal displacements in the in-place inclinometer (IPI) monitoring well. Comparisons of the FLAC3D finite difference simulation results and the surface, subsurface, and underground instrumentation results show that the measured IPI casing deformations are in reasonable agreement with those predicted by the FLAC3D models, and that the measured surface subsidence and underground pillar pressure are in excellent agreement with those predicted by the 3D models. Measured permeability changes were incorporated into a preliminary calculation to evaluate the effect of a hypothetical shale gas well leak on longwall ventilation. Results from this 2018 research clearly indicate that under shallow cover, the measured horizontal displacements within the abutment pillar are at least one order of magnitude higher than those measured in a 2017 study under deep cover and slightly higher than those measured in a 2014 study under medium cover. This research represents a very important step and initiative in utilizing the knowledge and science obtained from mining research to improve miner and public safety as well as the safety and health of the workers in the oil and gas industries"

Jan 1, 2019

By S. Kelebek, G. W. Smith

Four samples of galena, each prepared differently, dry ground chalcopvrite and real gar have shown various quantities of liberated sulfur corresponding up to nine equivalent monolavers on their surfaces as determined by the solvent extraction/UV analysis of sulfur using ethanol. The pretreatment of a dry ground galena sample with acidified ammonium chloride or neutral, saturated sodium chloride solutions rendered the mineral readily floatable. The collectorless floatabilities of galena pretreated with the former solution and of drv ground chalcopvrite have been evaluated in reference to the natural floatability of sulfur using the critical surface tension of floatability approach with aqueous methanol solutions. It is shown that the amount of sulfur- on these samples can be correlated with their flotation rate, which was found to he first order within the critical surface tension range. The larger the concentration of surface sulfur, the faster the sulfide mineral floats, thus, the greater its flotation rate constant.

Jan 1, 1990

By S. A. Elmquist

Research activities performed by Cleveland-Cliffs Research and Hibbing Taconite plant personnel during the last decade have resulted in the development of an improved autogenous mill grinding circuit. Minus one (1) inch autogenous mill trommel oversize material, con-sidered to be a critical size, is magnetically cobbed and then crushed to 100% minus 3/8" prior to reentry into the feed end of the mill. Autogenous mill capacity increases, up to 25%, have been measured in pilot plant tests using this approach and are also anticipated for the Hibbing Taconite concentrator which presently has reached a 15.5% improvement.

Jan 1, 1994

By John P. Albers

During the 1950's and 1960's a program of geologic mapping of counties has been underway in Nevada by geologists of the U. S. Geological Survey and the Nevada Bureau of Mines. The aping has been done principally at reconnaissance scales, with more detailed work in local areas. Geologic maps are either published or open-filed for about a dozen counties at scales of 1:200,000 or 1:250,000. One by-product of the geologic mapping has been the recognition of about 80 Tertiary volcanic centers from which large or very large volumes of volcanic material ranging from rhyolitic to andesitic in composition have been erupted. For purposes of this discussion these are regarded as the major centers; the tally does not include hundreds and perhaps thousands of small rhyolitic domes and plugs and basaltic vents. About 15 to 20 of the 80 major centers are believed to be calderas ranging in diameter from 3 to 25 miles. Some have been described in the literature by geologists of the Nevada Test Site and others. However, the vast majority of the 80 centers have not been described in print, and we are indebted to our colleagues for locating them for us in many of the counties. Briefly, we would like to express our appreciation to the following people all members of the USGS unless identified otherwise: Robert Coast, who has identified the centers in Elko County; Ron Willden, Robert Yates, and

Jan 1, 1968

By S. Tuylu, D. Adiguzel, A. Bascetin

"In recent years the fact that mining tailings cause serious environmental problems resulted in increasing number of studies about their disposal, storage and usability in various areas. Therefore the new studies about using the tailings for some purposes such as using in shotcrete or producing concrete have been increasing recently. The study is focused on applicability of tailings for producing shotcrete. Under this scope it is considered that mining tailings can bring many advantages in case of that they are used instead of sand, silt or fine aggregate in shotcrete applications. Most important advantages can be listed as decreasing shotcrete cost, decreasing amount if mining tailings to be disposed and the contribution to be provided on sustainable production of sources. The main objective of this study is the investigation of using mine tailing instead of fine aggregate in shotcrete. In this study, 10 shotcrete designs in different proportions were formed, and properties of the mixtures were identified. Then, the experimental results were statistically analyzed, the effects of the amount of the tailing material used on shotcrete properties were presented, and empirical approaches that can be used for the estimation of these properties were developed. INTRODUCTION The disposal of high amount mine tailing on the surface is caused a lot of problems in terms of environmental impact. Unfortunately, it is known that classic disposal techniques such as tailing dam cannot provide a solution these problems. The tailing dams which are usually used in the disposal of mining tailings bring along many problems in terms of cost, environment, and human health. So mine tailings are used in different production such as shotcrete. This technique is becoming increasingly common during recent years. The usability of mine tailings in brick and concrete production instead of cement and fine aggregate has been studied by many studies [1-4]. This situation has been promising for the usability of tailings in shotcrete which is commonly used for ground support especially in tunnels. Shotcrete (sprayed concrete) is applied mainly for construction of tunnels, shafts, renovation works and strengthening of slopes. Main advantage of shotcrete is fast development of strength, which quickly ensures stability of strengthened structure [5]. Shotcrete can be defined as spraying the grout consisting of water, aggregate, cement and optional additive mixture on the desired surface with a compressed air. According to the definition of the American Concrete Institute (ACI), it is the spraying of sprayed grout or concrete on a surface at high speed with air pressure [6]. In recent years, the use of shotcrete for the support of underground excavations is decreased in the mining industry. The design of shotcrete support for underground excavations is a very imprecise process. Strength and pumpability properties of shotcrete are very significant for determining suitable shotcrete design. Flow characteristics of the shotcrete must be determined for pumpability and fluidity of the material."

Jan 1, 2017

By Rolf Lange

Introduction The Harzwasserwerke, a public body of the Federal State of Lower Saxony, supplies drinking water to an area bordered by Braunschweig, Bremen, the Northern and the Western edges of the Harz-Mountains. From the very beginning in 1928, the Harzwasserwerke have been systematically constructing reservoirs in the western Harz which have the function of collecting and storing the frequently occuring flood waters as well as providing drinking water. The Grane-Reservoir with a capacity of 45 Million cu.m., the last of the big reservoirs, was built in 1968-1970. A system of connecting tunnels effectively enlarges the natural catchment area of this reservoir and the surplus waters of the Oker and Radau valleys - where floods occur particularly during the spring - are being conducted to the reservoir. By building the 4.800 m long "Radau-Tunnel", the waters of the Radau valley will now also be used more efficiently and its surplus waters will pass to the Grane Reservoir via this new tunnel and the Oker-Grane-Tunnel which was finished in 1970. The Project The Radaustollen has been planned and put out to tender by the Harzwasserwerke as a conventional "Freispiegelstollen". The horseshoe profile has a cross-section of 8 m2. Lining was required only in disturbed rock areas; lining of the whole tunnel was not necessary. The gradient of the tunnel is 4 % 0 rising = 25 m over the total length of 4.800 m.

Jan 1, 1979

By Milka Madahana, John Ekoru

Particulate matter is one of the leading pollutants in the mines and in the communities in the areas near or surrounding the mines. The availability of large Clinical and environmental data sets obtained from the mines has brought about the need to use better approaches to analyze the collected data. Prediction and control of particulate matter concentration in the mining environment is essential in minimizing air pollution and protecting the respiratory health of mine workers. The main objective of this research work is to analyze datasets obtained from a mining area using machine learning techniques which will then be followed by the real-time estimation of dust particulate in the mines. Datasets collected over 8 years in an hourly sampling rate from an open cast mine is cleaned and analyzed for trends and patterns. Artificial Neural Networks (ANNs), Support Vector Machines and decision trees techniques are applied to analyze and predict the particulate concentrate. The estimation of particulate concentration using Artificial Intelligence will significantly contribute toward the development of quantitative tools to be used in correlating of cause and effect of dust concentration in mines. The results obtained in this work will form a sub-unit of a respiratory health monitoring system for mine workers. The system is essential in the collection, analysis, and tracking of mine workers’ respiratory health, thus it forms part of an early intervention system for mine workers. From the existing theory, we expect the Artificial Neural Network will perform much better than previously used classical models.

Jun 25, 2023

By C. G. Treworgy

Geologists at the Illinois State Geological Survey are evaluating geologic and land use conditions that affect the minability of coal to determine how much coal is available for development using current technology and mining practices. Coal resources are being evaluated for selected 7.5-minute quadrangle study areas. In a central Illinois study area, more than 25% of the deep-minable resources were limited from development by unstable roof conditions resulting from thick unconsolidated sediments overlying thin bedrock overburden. In some southern and southeastern Illinois study areas, geologic conditions associated with a paleo-channel limit the minability of significant resources of low-to medium-sulfur coal. Some features which were thought to limit mining, such as areas of closely-spaced oil wells, have been found to have minimal impact on the amount of coal recovered.

Jan 1, 1995

By R. Tanaskovic

Unfavourable climatic conditions in stopes are of significant economic and social importance due to the following reasons: - Working effect is much lower leading to decreased output and work productivity disregarding implementation of mechanization. - Manpower operating capability decreases much faster under unsatisfactory climatic conditions. Under normal climatic conditions a workman would expend much less effort in line with a shorter effective time for the achievement of identical production effects since the work would be more efficacious. The objective of study of problems and climatic conditions is to make the working environment in mines suitable for normal development of operations. Lowering of mining works to increasing depths and winning of a growing number of small orebodies over a broad area makes the problem of creating suitable climatic circumstances more complex. Mining costs are growing due to bench conditions in line with decreasing metal content in the ore, so frequently the investments required for creating favourable climatic conditions represent, in addition to the selection of mining technology, a very important parameter when making decisions regarding exploitation. As known, the basic factors affecting climatic operating conditions in mines-are: temperature, humidity and speed of air flow, implying that the climatic operating conditions are closely related to mine ventilation. Usually, the concept of unfavourable climatic operating conditions includes increased mine air temperature and humidity and low air flow velocity so that heat exchange between human organism and the working environment is impeded or reduced to minimum. Metal mines in Yugoslavia are characterized by the existence of a large number of active faces - stopes and horizons and lowering of mining operations to increasing depths, so that face ventilation solutions are more and more complex. Since its foundation (1961), our Institute is engaged in investigation of factors influencing climatic circumstances improvement of calculations for air distribution and distribution control in complex ventilation networks and study of problems related to ventilation of large volume and irregular configuration faces, as well as application of gained knowledge in our mines. The paper presents the knowledge and experience gained in the case of Lead and Zinc Mine "Trepca" - Stari Trg.

Jan 1, 1980

By Robert D. Brown

The purpose of this paper is to tell a story - and it is a story with a moral. My topic is Present Trends in the Tax Environment Affecting Mineral Development in Canada, and the first thing to recognize is that, with depressed metal prices and weakening western economies, taxes, in and of themselves, are not really the cause of the Canadian mining industry's present doldrums. But the character and level of mining taxes in Canada has had a profound influence on the development of the industry over the past decade, and the expectations of what taxes the industry will face in future years will influence the industry's further growth. My theme today is that, in Canada, our tax system has, in the past, served as a negative and destabilizing influence in the mining industry: it has contributed to a major short-fall in investment commitments and hence in the contribution which the mining industry can make to the Canadian economy, and the adverse effect on the industry of previous high tax rates was made far worse by the confusing, contradictory and perverse nature of the tax system itself. This is a story with some happy parts in it, and, in fact, governments in Canada did learn, haltingly and grudgingly, that there are limits on the amounts that governments could safely extract from the industry, and that some assurances of long term fiscal stability were necessary if investors were to be induced to make massive commitments which could only be recovered over very lengthy periods.

Jan 1, 1982

By H. Y. Yang, L. L. Tong

For gold recovery, a Chinese refractory, high-sulfur gold concentrate was subjected to biooxidation with high pulp density in a single stirred-tank reactor. The flotation concentrate contained 36.9 percent sulfur (S) and 33.9 percent iron (Fe). Different experimental regimes for biooxidation were applied. With a mixed culture and by controlling the amount of addition of the gold ores and the pH of the biooxidation system, maximum iron oxidation of 82.6 percent and sulfur oxidation of 79.3 percent were achieved. The experimental results indicate that the pH control was beneficial to the biooxidation of this concentrate. Approximately 28.4 percent of elemental sulfur (S8) was found in the oxidizing slags. Two dissolution mechanisms of elemental sulfur are proposed: (1) FeS2 → S80 → S2O32− → SO42− and (2) FeS2 → S80 → SO42−. The high pH had a positive effect on the reduction of the S8. The results of thermodynamic analysis indicate that as an oxidant the dissolved oxygen can effectively reduce the Gibbs free energy of the pyrite oxidation process and, compared with the reaction of ferric iron as the single oxidant, the oxidation of pyrite is easier. The efficiency of the gold recovery was related to the iron oxidation as well as the sulfur oxidation. Gold and silver recoveries of 92.4 percent and 66.4 percent, respectively, were achieved.

By J. Hanna, R. Kalathur

Over the years, Alabama's coal industry has generated, during mining and cleaning operations, about 150 million st of fine waste coal, with this total increasing at a rate of 2 million stpy. Reclamation of the fine-size wastes (containing 20% - 60% clean coal by weight) provides, free of charge, mined and crushed feed stocks for coal recovery. Also, the removal or recovery of pyrite from the tailings should eliminate a major source of acid-water pollution. Tests were made on the impounded wastes and current plant discharges to recover the coal fraction by sizing, gravity and flotation techniques. Gravity separation of the +100-mesh material produced commercial-grade coal averaging 7.6% ash, 0.8% sulfur and 13,471 Btu/lb. However, the coal yield, at about 31 % - 56%, was relatively low. Froth flotation, using mechanical and froth column methods, gave similar coal products at much higher coal recovery rates of 87% - 93%. This coal analyzed 10% ash and 1.1% sulfur.

Jan 1, 1993

By D. D. Misra

Though computer simulation of coal beneficiation has been in use for nearly two decades the models used in the programs for the simulation of the crushing processes concentrate mainly on the size distribution. This paper suggests the use of an empirical equation approximating to the cumulative probability or error function for the simulation of the liberation process in coal crushing. The algorithm outlined here can be incorporated in a computer program already having a size distribution model.

Jan 1, 1989

By Norm Greenwald

The Environmental Protection Agency ("EPA") has been attempting to develop a federal regulatory program for mine waste under Subtitle D of the Resource Conservation and Recovery Act since 1986. Recent regulatory and legislative events are now bringing this goal closer to reality. This paper discusses the mining industry's perspective on a number of the issues currently being addressed at EPA's Policy Dialogue Committee and in Congressionally-sponsored negotiating sessions.

Jan 1, 1992

By M. Bidart, V. Sawyer, M. Saunders Macdonald

A number of open pit gold mines in Nevada extract ore from areas that are below the natural groundwater elevations. This necessitates dewatering, which requires a method for the disposal of the extracted water. Some of these open pits extend well below, the water table with dewatering volumes greater than 10,000 gpm (38,000 L/min). Some mines with large volumes of dewatering water have constructed reinfiltration basins to reintroduce the water into the groundwater system at a point some distance from the pits. This paper presents an overview of the state of the art of reinfiltration projects, including the permit process for such projects in Nevada. The paper includes the necessary engineering considerations.

Jan 1, 1997

By M. Moats, I. E. Paschalidou, K. Awuah-Offei

Tellurium (Te) is a rare metalloid that is predominantly produced from the treatment of anode slimes formed during copper (Cu) electrolytic refining. The US Government lists Te as one of the 50 critical minerals, partly, because of its use in thin-film photovoltaic (PV) technology. Given policy initiatives to increase Te production, it is important to evaluate the life-cycle environmental impacts of Te recovery as a by-product of Cu processing. The literature contains a few specific life cycle assessment (LCA) studies of groups of metals that include Te without proper regard to impacts per life-cycle stage of Te production or the effect of allocation on the results. This study builds an LCA model of the production system of Te from anode slimes treatment to evaluate the effect of allocation on life-cycle impacts. We build life cycle inventories using data from the Ecoinvent v3.7.1 database, literature, and engineering calculations and allocate impacts in proportion to products’ mass and economic value. The results show that economic value-based allocation yields greater impacts than mass-based allocation indicating the significant effect of the allocation approach on life-cycle impact estimates.

Feb 1, 2023

By Adrian C. Dorenfeld

The lesser developed countries (LDC's) may be classified into two categories: 1) oil producers, and 2) non-oil producers. The non-oil producing LDC's, as a class, are at present in very difficult financial straits. (1) Since the quadrupling of world market crude oil prices in 1972, an ever greater share of the LDC's export earnings have gone to pay for oil imports, in-stead of national reinvestment. The LDC's inter-national debts--much of it to pay for oil--have soared to record levels, with consequent limits for future credits. (1) Again, this inhibits future national investments, and there does not seem to be an end to the future increase of Organization of Petroleum Exporting Countries (OPEC) prices. Indeed, some of the economic difficulties in some metal markets--particularly the imbalance of production vs. markets for copper, can be traced indirectly to the OPEC cartels' heavy-handed impact on copper producing LDC's which must produce copper at any price to meet their oil bills. (2) Among the major oil importing LDC's are the Philippines and South Korea. 50th nations have substantial cement industries. The South Korean industry is geared for major export markets in the Far East. Both nations have ambitious plans for economic growth in order to accommodate burgeoning populations with ever increasing expectations for high standards of living. These plans had some success, more or less, until the high OPEC oil cartel charges had to be borne. Now, in common with all oil-deficit areas, the Philippines and South Korea are seeking lower cost sources of energy. Both countries have coal deposits. In the case of the Philippines, the reserves are in scattered, relatively small deposits. Most of the coal deposits are faulted, folded and, in general present formidable production problems for limited reserves. Nonetheless production has been on the order of about 70,000 to 150,000 tons per year in the last 30 years. Prior productions (1920-1941) varied between 9,000 Co 150,000 tons per year. (13)

Jan 1, 1978

By R. E. Ray

As coal reserves at shallow depths continue to be exhausted, a number of US coal companies are developing seams previously considered too deep to mine economically. Because of increased cover load, mines operating in deeper seams face unique ground control problems. In addition, the volume of methane gas in coal beds increases with depth, and ventilation requirements are much more stringent for deep mines than for shallower mines. When the longwall mining method is wed at great depths, ventilation, ground control, and operational considerations all influence the design of longwall panels. This paper examines these influences, particularly ventilation and operational considerations, on the feasibility of two-, three-, and four-entry longwall development panels in Jim Walter Resources' four deep mines.

Jan 1, 1988

By Felicia F. Peng

The plant data were collected from three streams around a dense medium drum for coarse coal cleaning operated at various volumetric ratio of medium-to-feed. The effect of the volumetric ratio of medium-to-feed (MF) and particle sizes on the performance criteria, g50 and Ep, of the dense medium drum. These measured data were adjusted and calculated for the yields and balanced relative density distributions by mass balanced method based on the statistic principle. These balanced data were then used to formulate the mathematical models of the separation distribution curves for the various feed size intervals. The correlation equations for the g50 and Ep as the function of inverse of the feed size, and MF and total throughput were established. A numerical algorithm utilizing the Secant method, based on the root searching principle, was developed for yield optimization and simulation of dense medium drum separation to improve the separation efficiency and hence the product yield. The relationships between the direct ash content and relative density of the particles in feed and the products were established and incorporated into the numerical algorithm for predicting the product quality.

Jan 1, 1996