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By K. Soga

DOWA has long been specialized in the treatment of complex massive sulfide ores from exploration through smelting. Its competitive advantage derived from ore dressing technology to dress and concentrate complex ore to various kinds of metals concentrates. With this technology, the company recovers as many as seventeen different nonferrous metals. Therefore, it is crucial for the environment management and recycling business both to recover valuable elements like gold, silver, copper etc. and to handle hazardous elements in safety. From this view point, the nonferrous metal industry has a potential to play an important role; that is "The Anchor of Recycling" or "The Joint of Recycling Loop". By utilizing these mining, smelting and refining technologies, know-how and facilities, DOWA became a leading waste treatment, soil remediation and metal recycling company in Japan. This knowledge is now being applied in China .

Jan 1, 2007

By J. Bruce Clemmer

[Gypsum is one of the mo .. t iJf.l)ortant nonmp.tal1.ic T!1inerals, as is indicat-? ed by the fact that tlle Uni ted states cO!1sUl:Ied p, roximn..tely 3,500,000 tons of natura.l and calcinecl e::,j;-psum in 1937. The b\.'.ilr:.in.; traces \"fe.ro the largest users and required 2,520,000 tons of calcine for the r-roductiop. of plaster,]

Jan 1, 1941

By Jürgen Kretschmann

The Islamic Republic of Iran is a very important producer of raw materials in the world. The country holds 68 types of minerals, including salt, sand and gravel, chrome, lead, zinc, copper, coal, gold, and iron-ore. With more than 37 billion tons of measured and indicated reserves and 55 billion tons of total mineral resources, Iran is ranked among the 15 major mineral-rich countries. Sangan iron-ore mines (SIOM) is one of the biggest iron ore mining complexes in Iran, located in a remote, but strategically important area near the Afghanistan border. The Iranian government has planned several mining projects in this region for a stepwise development over the next 5 years to satisfy the growing demand of the Iranian steel industry. In cooperation with private companies, these projects shall be realized as sustainable as possible. This paper introduces SIOM and describes socially responsible activities undertaken during the initial development of this mining complex. The effects of these activities will be demonstrated. Unique attributes of the Sangan area have a significant impact on the acceptance of SIOM by regional stakeholders. The government has made several social investments that benefit workers´ families and the community. They are attempts to build social capital for the mining operations and demonstrate a commitment for socially responsible mining to the communities and the local population. They aim to create a balance between the local and regional expectations and requirements and the necessity to secure the corporate profitability at a reasonable and sustainable level. Investment in socially responsible activities is not a choice but a necessity to improve the relations between mining companies and stakeholders in the communities. It is recommended that social investments should be carefully planned and implemented from the early stages of mining activities, and should proceed throughout the life cycle of the mines.

Aug 1, 2013

By Getu F. Biftu

There is general agreement among scientists that global surface temperatures have been increasing during the past decades. The increase in temperature is postulated to be the result of either an increase in greenhouse gases emission or climate variability (i.e., due to variations in sun or volcanic activity or El Nino and La Nina events) during past decades and may continue to increase. The effects of a predicted rise in the Earth?s surface temperature include an increase in average global evaporation and increase or decrease in precipitation (Bloomfield, 1992; Mann et al., 1991; Vinnikov et al., 1990; Gan 1995; Zhang et al., 2000a). The general circulation models (GCMs) project a global warming due to greenhouse effects of 1.5-4.5°C by the mid 2050s, with the most pronounced changes taking place in northern latitudes (Nicholls et al., 1996). However, similar predictions at a watershed scale or even a regional scale using GCMs are mot possible yet (Arnell et. al., 1996; Georgievskii et. al., 1996; Zhang et al., 2000a). Detection of historic trends, changes and variability in climatic variables is another indirect means of understanding potential future changes or variability at regional and local scales. The main objective of this paper is to review studies related to climatic change or variability and associated hydrologic changes at a regional scale and local scale, particularly those studies applicable to the Oil Sands Region (OSR) of Alberta. This paper identifies gaps in our current understanding of the hydrologic processes that may be affected by climate change; it discusses potential implications to developments in the OSR; and it explores mitigation opportunities including several that have already been implemented.

May 1, 2004

By Austin Whillier

INTRODUCTION Use of air-cooling or refrigeration equipment in underground mines is needed when conventional ventila¬tion techniques do not maintain acceptable environ¬mental temperatures in working areas. Because refrig¬eration can be very expensive, it should be implemented only after all possible and practical steps have been taken to eliminate or reduce heat sources in the mine. As an example, to prevent the main ventilation fans from contributing heat to mine air, they should be located in the air return and not in the air intake. It is particularly important to prevent any direct contact between hot water and ventilation air, especially in mines which encounter large flows of hot fissure water. Any water hotter than the prevailing wet-bulb temperature of the ambient air must be removed by pipes located as close as possible to the water source. This hot water must not be allowed free contact with the incoming ventilation air at any time during the water's passage out of the mine. Although insulation of the pipes carrying the hot water is seldom necessary, direct contact between the air and the water must be prevented so the warm water cannot evaporate. REVIEW OF COOLING PRACTICES Spot Coolers vs. Centralized Refrigeration To eliminate a few specific hot places in an otherwise cool mine, it is possible to use devices known as "spot coolers." A typical spot cooler that uses chilled water is shown in Fig. 1. These devices consist of self-contained refrigeration units that are often mounted on rail cars for haulage to hot spots. The cooling capacities of such spot coolers usually are limited to about 100 kW or 30 "refrigeration tons." A refrigeration ton represents a cooling rate that produces 1.0 st of ice in 24 hr; that is a cooling rate of 3.517 kW (200 Btu per min). Typically, the electric-power consumption to drive the compressor motor of the refrigeration plant in mines is 1.0 kW per refrigeration ton, corresponding to a coefficient of per¬formance of about 3.5. The principal difference between spot coolers and centralized refrigeration plants is the method of re¬jecting heat from the refrigeration system. Centralized refrigeration plants always discharge heat into the reject or return airflow of the mine; often that is the primary influence in selecting the location for the underground refrigeration plant. Heat from spot coolers usually is rejected into drain water or into air that is not flowing to the location requiring the cooling. As a result, spot coolers remove heat from troublesome hot spots in the mine, injecting that heat-plus the electrical energy used by the cooling unit itself-into other working areas where the ambient conditions are cooler. In effect, this is "robbing Peter to pay Paul." In deep, extensive mines, spot coolers usually pro¬vide only temporary and, over the long term, expensive solutions to localized cooling problems. Centralized re¬frigeration plants are preferred for such mines, with cooling distributed throughout the mine as required. Fig. 2 illustrates a typical underground centralized re¬frigeration plant. Centralized plants lend themselves to improved maintenance at reduced costs while offering the economy of size. Refrigeration plants of larger unit sizes have considerably lower initial costs than smaller unit sizes. The remainder of this chapter is devoted to large refrigeration plants, with no further consideration of spot coolers. Cost of Refrigeration Total Cost: The total cost of refrigeration amounts to about $200/kW of cooling per year (1981 US $). This total cost breaks down into approximately three equal parts: 1) Financial charges, which include the interest and amortization on the capital cost of the initial installation, and the cost of necessary underground excavations. 2) Operating and maintenance costs which include the cost of the electric power to drive the refrigeration plant's compressors. 3) Distribution costs which include costs for pump¬ing, insulated piping, and air-to-water heat exchangers. The local cost of electric power, the number of operating months per year, and the method of refrigera¬tion distribution all contribute to the actual costs in¬curred in a given application. However, the variations usually are limited to no more than ±30% of the $200/ kW per year total cost figure. Cost Per Ton: Refrigeration cost per ton of mineral production can be calculated if the annual production tonnage from the refrigerated section of the mine is known. In most cases, this cost will be less than $1 .00/t. However, in deep mines with high rock temperatures, such as those found in South Africa, the total cost of refrigeration can increase to several dollars per ton of broken rock. Distribution In deep extensive mines, distributing refrigeration often accounts for about half the total cooling costs. As a result, careful consideration and planning must be

Jan 1, 1982

By Ralph H. Sweetser

BENEFICIATION of iron ores from the blast-furnace point of view means more than the usual enrichment of the iron contents by the removal of a large part of the clay, carbonic acid gas, silica, or moisture of the natural ore; it includes all these, but it also embraces several other mechanical .processes made , necessary by the exacting requirements of present-day blast-furnace practice. The increasing use of iron- bearing by-products, to as much as a third or more of the total ore burden, has introduced still another series of processes for improving the blast-furnace ore burden. As we look back over the past three decades of blast- furnace practice 'in. this country, we see that many of the blast-furnace troubles were directly due to lack of proper preparation of the iron ore burden,, and we realize that beneficiation in one form or another would have remedied the trouble. This was particularly true in the smelting of magnetic iron ores, where run-of- mine ore included such big lumps of 'magnetite along with rich fines that the furnace operations were greatly retarded and control of the furnace such as is usual today, was completely unknown.

Jan 1, 1930

By K. Kim

A site characterization strategy formulated for the probabilistic design of underground structures is presented, which takes into account the variability of rock properties and the stochastic nature of the rock failure process. It entails determining probability distributions of rock properties by utilizing the theory of extremes and Monte Carlo simulation. Laboratory and field test data are analyzed and presented to illustrate the methodology. The results indicate that the distributive characteristics of rock mass properties can be estimated using empirical relationships currently available. This results of analyses can be incorporated into the design of underground structures, and then, the relative uncertainties of the failure probability of the structures can be assessed.

Jan 1, 1995

By Bird. M.

As the Cadia mill was the first 40ft diameter SAG mill, commissioned in 1998, its performance, liner and discharge design attracted considerable international attention. Twelve years on, the liner design and the control philosophy are being readdressed to further improve the mill?s performance. A comprehensive series of 3D liner scans, over life of the liner, have been used to calibrate liner mass loss and progressive changes in the liner profile. This data is being used to provide true charge mass and mill filling, plus progressive trajectory profiles over life of liner. This information, along with measures of mill performance over liner life, is being used to select the optimal operating conditions as the liner wears, and hopes to inform future liner design.

Jan 1, 2012

By P Cesare, S Munro, D Wandel, R A. Bearman

Consideration of the processing plant operational envelope is a key factor in production scheduling,and therefore mine planning, for any mining operation. In many cases hard-wired or regressionbased tonnage-grade-recovery relationships are used as mine planning constraints and as a means of valuing the system output. In extensions of this type of approach, various regressions can be used to describe throughput limits, based on a number of global metallurgical parameters.The ultimate position for the optimisation of a mine plan and production schedule is to have a full process plant model running as an integrated part of the mine planning exercise. A plant model suitable for this needs to have all the required sensitivities to input parameters such asfragmentation, grade, mineralogy, strength and hardness. The model then needs to convert these to performance measures for the plant, which include recovery, throughput, product size distributions, energy consumption, water use and operating cost.In this paper an approach is outlined that takes this view and then goes beyond it to provide a full, time-based bottleneck identifi cation and valuation tool.Using such an approach it becomes possible to run mine plans and production schedules in windows of days, weeks, months and over the life-of-mine with a time-enabled process model acting as the active constraint. In this way virtual bottlenecks can be identifi ed for various mine plans and schedules well ahead of time. The value of de-bottlenecking can be defi ned, not just at a plant scale, but in terms of the overall mining operation, and the data can be used as the basis for capital investment decisions.CITATION:Bearman, R A, Cesare, P, Munro, S and Wandel, D, 2014. Incorporation of a full process plant model as an active constraint for mine planning and production scheduling, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 121–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By J. W. Davis

The storage stability characteristics of a diesel type fuel were determined to evaluate the effect of the polar compounds in the fuel. These compounds, comprising most of the nitrogen and oxygen containing compounds and many sulfur containing compounds, were separated from the fuel with a chromatographic column. This fraction was further separated into three polar extracts by graded elution through the column. Each extract was characterized. A storage program using the depolarized fuel, the fuel as received, and blends of the extracts with both fuels, was conducted. Results showed that the removal of the more polar components stabilized the fuel. Blending the polar extracts with the original fuel and with the depolarized fuel in the same ratio as they existed originally and at two and three times the original ratio increased the amount of gum present before storage, but had little effect on the formation of additional gum during storage. Distillate fuels produced by commercial refining of petroleum contain traces of organic nitrogen, sulfur, and oxygen compounds that are more polar4 than the remainder of the fuel. Recent laboratory studies by the Federal Bureau of Mines (1),6 in which these compounds were removed from a fuel, have shown that they influence its storage stability. The objective of this work was to determine the amount of these compounds present in a fuel and their effect upon its stability in storage. To evaluate the role of these polar compounds, it is necessary to remove them from the distillate fuel. Many can be removed by chemical treatment (2), but such treatment precludes reblending the polar components to approximate the original fuel composition. Solvent extraction is free of some of the criticism of chemical treatment, but it is more difficult because of the complex mixture from which compounds must be removed.

Jan 1, 1961

By George S. Rice

"The emission of hydrocarbon gases from coal beds and contiguous strata causes many accidents in coal—mine workings, the number of fatalities so caused being second only to those due to falls of roof. Gases tend to increase in amount with depth of coal mining, hence the danger of explosion is increased with depth. The pressure of the gas in virgin—coal areas at a distance from mine workings likewise tends to increase with depth from the surface, probably due to corresponding increase in hydraulic head and possibly, when the gas is held in nonporous formations, to greater ground pressure. The rise in gas pressure with depth under usual conditions is shown in wells drilled from the surface and in some coal fields in drill holes into the face of workings; however, under normal conditions of coal formation gas does not issue into workings under high pressure because the coal and adjacent strata have many bedding and joint planes which allow the gas to escape freely at the face of the workings. The rare occurrence of instantaneous outbursts of gas, with violent effects referred to later, constitute the exception.Variations of volume and pressure of fire-damp or methane found in different coal beds by wells at a distance from mine workings, are analogous to variations in volume and pressure of natural gas found in different gas and oil sands, although in general the pressure tends to increase with the depth. Sometimes, however, in tight sands higher in the formation the pressure of gas therein is abnormally high, and on drilling the well deeper gas in the lower strata may be found at lower pressure."

Jun 1, 1934

By M Forbes, R Jeuken

Brownfields geoscience measurement such as drilling and surface geophysics can be costly and it is often difficult to weigh the cost of data collection and processing against the value it unlocks at the time of extraction. This makes it difficult to prioritise geoscience expenditure and find the optimum intensity of geoscience activity across competing assets. There are multiple options for managing resource uncertainty and spatial variability through mine planning and resource engineering such as varying marketing strategy, adjusting stockpile or other infrastructure design and product blending. Consideration of these alongside increased data collection further complicates finding a comparable value of geoscience programs to determine the right blend of geoscience measurement and engineering controls. Concepts similar to Value of Information (VOI) analysis which is applied to strategic planning can be used to estimate the value of geoscience measurement and pit sequencing at tactical planning and operational timescales. This involves the quantification of resource uncertainty and prediction of how it will affect resource extraction. This paper outlines this process and demonstrates its use to prioritise geoscience at BHP Coal Assets. The value of infill drill programs in enabling operational stability is quantified and compared the value of engineering controls like increased stockpile capacity. This study supports that idea that the application of VOI methods to bulk mining at tactical time horizons has potential to inform geoscience planning and resource engineering not just separately, but as part of a unified strategy for managing resource uncertainty.

Mar 22, 2022

By J. Feldman

This report contains a description of the distillation laboratory at Bruceton, Pa., which was established to aid in the separation and identification of the products produced in the synthetic liquid fuel processes under study there. Compounds present in synthetic liquid fuels may include aliphatic from C1 to C60 or greater. Alcohols, ketones, esters, aliphatic carboxylic acids, saturated hydrocarbons, olefins, and diolefins are all found in Fischer-Tropsch products. Coal-hydrogenation products contain, in addition to aliphatic compounds, a large proportion of naphthenic material and aromatic compounds ranging from benzene to coronene; in addition, appreciable quantities of tar bases and tar acids are present. In designing the laboratory, therefore, provision had to be wade for the greatest amount of flexibility and versatility. A great deal of standardization of basic equipment had also to be designed to permit interchange of parts and services.

Jan 1, 1951

By Congling Shi, Marek Borowski, Yue Wang, Jianwei Cheng, Xixi Zhang, Xuan Xu

As the first barrier to prevent accidents caused by explosions in underground coal mines, the integrity and stability of mine seals have great effects on mine workers’ lives and underground production safety. In this paper, the mechanical responding performance of typical mine seals under the impact load are studied by using numerical simulation method. By such simulation studies, the safety of different seals subjected to the explosion load is evaluated. Seals’stability are also investigated under effects caused by various influence factors including thickness of mine seal, cutting depth into surrounding rocks, rock type, and the roof-tofloor convergence under given the explosion load. The research results can provide theoretical basis and reasonable improvements for mine seal’s construction practices for improving its anti-explosion performance.

By L. Tercero Espinoza, F. Marscheider-Weidemann, C. Gandenberger

"A reliable supply of non-energy raw materials is a precondition for the functioning of the European economy. In line with its importance, the issue of raw materials supply has become more prominent in the past years, especially owing to turbulent raw material markets. However, these turbulences are not due to depletion of the geological resources but to a missmatch of (expected) supply and (expected) demand, with several interacting factors influencing the markets both from the supply as well as from the demand side. A recent evaluation, published in June 2010 within the framework of the EU Raw Materials Initiative, sought to bring together these two sides of raw material markets and asked the question "which raw materials are critical for the EU?" Herein we present the methodology used by the Ad-hoc Working Group on Defining Critical Raw Materials and the results obtained, complemented by results from the study "Raw Materials for Emerging Technologies"."

Jan 1, 2011

By Robert Strachanm

The East Kootenay coal-field, situated close to the boundary between the provinces of Alberta and British Columbia, is composed of four small areas locally called the Crow's Nest Pass, the Upper Elk, the Flathead and Crown Mountain, and comprises an area of about 3 78 square miles. From eleven to twenty-five seams have been exposed of two feet and over in thickness, with a total thickness of about 200 feet of coal, and reckoning about one hundred feet to be workable, gives an estimate of coal available of about thirty-seven billion tons. The coal is a high-grade bituminous, occasionally tending towards anthracite, and the majority of the seams furnish a. very good quality of coking coal as well as an excellent steam coal. The coal-field is found in the mountain ranges in long narrow strips. The age of the fonnation and the thickness of the covering beds have had considerable influence on the character of the coal, and lateral pressure and disturbances in the process of mountain-building have wrought great changes. With such an abundance of coal, it has been a disappointment that the East Kootenay field has not figured larger industrially. So far only one portion of the coal-field has been utilized. This is the Crow's Nest, where, in 1898, the Crow's Nest Pass Coal Company commenced development. Access to the coal seams was easily obtained, the mountain creeks having eroded away the covering, and mines were driven into the coal seams. In that year about ten thousand tons of coal were produced from the mine at Coal Creek.

Jan 1, 1924

By Leon E. Esparza

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 16,927-acre Pryor Mountain Wilderness Study Area (MT-067-206), part of the 3,955-acre Burnt Timber Canyon Wilderness Study Area (MT-067-205), and part of the 4,550-acre Big Horn Tack-On Wilderness Study Area (MT-067-207) to evaluate their identified mineral resources. The Burnt Timber and Big Horn Tack-On study areas contain 3,430 and 2,550 acres, respectively. The three areas are in Carbon County, MT, and Big Horn County, WY, about 13 miles north of Lovell, WY. No identified resources exist in any of the study areas. Bureau of Mines personnel reviewed literature, searched county mining records and examined prospects, claims, and mineralized areas to determine whether identified mineral resources existed. The three study areas are within the Pryor Mountain unorganized mining district. U.S. Department of Energy production records indicate there were 223,000 pounds of uranium oxide (U308) and 236,000 pounds of vanadium pentoxide (V205) produced from 19 properties within the mining district. The average ore grade was 0.36 percent [3,600 ppm (parts per million)] U308 and 0.416 percent (4,160 ppm) V20S. Only the Pryor Mountain study area has current claims, the 50 claims of the S0S group.

Jan 1, 1986

By I. A. Lesk

The various materials utilized in the construction of integrated circuits, and the resultant materials interfaces, are discussed with emphasis on a materials system that is compatible with all types of integrated circuits and minimizes the number of different interfaces. Problems with interfaces may originate in the silicon, on its surface, and between other materials within the integrated-circuit package independent of the silicon. ThE difference between integrated-circuit theory and practice may generally be spelled out in terms of the difficulties in fabricating a desired structure. There are, of course, problems in forming the requisite materials, of the necessary composition and geometry, where needed. A distinct class of problem, however, is associated with interfaces— generally between different materials, but occasionally between regions of the same material. We require that each interfacial system perform its proper electrical, mechanical, and thermal function, and do so in an unchanging manner with time under the most severe operating conditions. In a practical sense, we deal in nonideal systems, such that it is generally not possible to form an interface exactly the way it was intended, even if we allow for a knowledge of the practical limitations of the fabrication system. Another way of looking at this situation is to realize that, when we form a group of interfaces under apparently the same experimental conditions, there are often differences of important consequence between them. Very high-magnification pictures, such as are obtained by an electron microscope, reveal fine structure that often differs over the area of a given sample, as well as from sample to sample. Low-magnification pictures look better, but don't eliminate the problem. The trend towards integrated circuits, and away from circuits fabricated utilizing separate components, is very strong in many areas of electronics. A typical silicon monolithic integrated circuit, still in place in the wafer on which it was fabricated, is shown in Fig. 1. The increased reliability which is being experienced through the use of integrated circuits can, to a large extent, be credited to the reduced complexity of the interface system that is present in the electronic system. A glance at Fig. 1, however, with all of its epitaxial and diffused p-n junctions, and interconnect system, shows that interfaces have been far from eliminated. Fig. 2, depicting a schematic cross-sectional view of a (partial) typical integrated circuit, illustrates in detail the numerous interfaces that occur in this type of structure. Besides the individual circuit elements, there are interfaces for isolation, and, Fig. 3, even a crossover requires a series of interfaces. What has been accomplished, however, irrespective of whether or not the total number of interfaces in the circuit is increased or decreased, is that the variety of interfaces is very much reduced. This is because there are fewer materials involved. Since the expense incurred in an R & D program to improve reliability is pretty much directly proportional to the variety of interfaces involved, it is economically advisable to work with integrated circuits for highest reliability. That is not to say that circuits built using standard components could not be made as reliable as integrated circuits, but that the expense involved because of the more complex over-all interface system would be much greater. Although electronic performance utilizing integrated circuits with all silicon elements (i.e., transistors, diodes, resistors, capacitors) is adequate for many applications, there are numerous instances where thin-film passive elements must

Jan 1, 1965

By John C. Edwards

A computer program, developed for the Bureau of Mines under contract, predicts in a quasi-steady-state approximation the ventilation and contaminant concentrations and temperatures when a fire occurs in a multi-level mine. For periods of time in which there is no significant change in the ventilation, yet a fire is producing fumes, a real-time fume concentration throughout the mine is calculated. Multiple and time-variable contaminant sources can be simulated. Recirculation paths that can develop provide a mechanism for increasing the fume concentration in the mine network and are identified by the computer program. This report contains a listing of the Fortran computer program as well as the required format of the input data. Two examples are provided of the real-time spread of smoke from a fuel-rich fire throughout a multilevel mine. The first example considers an operational exhaust fan as well as a booster fan. The second example evaluates the real-time smoke spread following a failure in the exhaust fan; recirculation occurs in this latter case.

Jan 1, 1982

By E. J. Sun

The ADS system was developed to reduce accidents related to haul trucks operating under low visibility conditions in surface mining and construction sites, which is based on the GPS, mesh-wireless networks, and the Google-Earth 3D graphic engine as the graphic interface and mine-mapping server. This system has the capability to pin-point and track vehicles in real time using a 3D interface, which is based on user-based AutoCAD mine maps using the Google-Earth graphics interface. All equipped vehicles are shown in a 3D mine map stored in a local server through a wireless network. When low visibility conditions are present, the system indicates available exit/escape routes for driver safety. The research results indicate that the ADS system potentially increases reliability and reduces uncertainty in open pit mining operations by customizing the local 3D digital mining map, constructing the truck 3D models, tracking vehicles in real time using a 3D interface and indicating available escape routes for driver safety.

Oct 1, 2009