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By M. Frenzel, D. Ebert, K. Bachmann, A. D. Renno, R. Möckel, J. Gutzmer, J. Krause

With the increasing demand for metalliferous and mineral raw materials, and consequent depletion of the global natural resource base, the possible utilization of secondary raw material sources is receiving more and more attention. In the present study, we present results from a detailed vanadium deportment study of three basic oxygen furnace slag (BOS) samples known to containing elevated bulk concentrations of vanadium (V). Complementary analytical methods that were used to quantify the abundance and composition of V-containing phases include SEM-based automated mineralogy, Xray fluorescence (XRF) analysis, and X-ray powder diffraction as well as electron probe microanalysis. The vanadium deportment was quantified using Monte-Carlo simulations of the data obtained from automated mineralogy and electron microprobe analysis. The total V concentrations identified by XRF are between 1.7 and 2.2 weight percent V. The most important hosts of vanadium are larnite-, brownmillerite- and portlandite-solid solutions. In two samples, calcium carbonates also significantly contribute to the V deportment, while wuestite, lime and native iron do not contribute significantly to the vanadium deportment. A thorough consistency check identifies considerable uncertainties in the density of the Vbearing phases as the most likely reason to explain remaining discrepancies between measured and calculated V values.

Aug 1, 2024

By C. D. Taylor, A. L. Mazzella, A. L. Martikainen

In fluctuating airflow, continuous air velocity recording is the most reliable method of air velocity measurement. It allows for fast recognition of changes and the calculation of long-term averages. Also, it enables the mine operator to identify when the airflow has decreased to a point requiring action. Using ultrasonic anemometers provides an accurate option for continuous air velocity monitoring. This paper provides information about the effect of common obstructions in underground mining on air velocity readings. Stationary and moving obstructions are used to represent workers and equipment that would cause discrepancies in measured airflow. Also, it is important to know how large of a sample size is required to ensure reasonable accuracy of results. Statistical analysis is used to evaluate the required sample size. The sampling procedure is further studied by comparing two different sample rates. The results show that obstructions provide noticeable differences in air velocity measurements. Also, movement of obstructions can be recognized from changes in results. Surprisingly small sample sizes provide reliable air velocity information. Standard sample rates are found to be suitable for the underground environment.

Jan 1, 2011

By Willard A. Murray

Investigations of underground coal gasification (UCG) have been actively pursued by the U.S. Department of Energy since the early 1970s; the Lawrence Livermore National Laboratory (LLNL) conducted its first field experiment in 1976. In conjunction with field and laboratory studies of the process of recovering energy in the form of combustible gases from the burning of coal deposits in situ, an extensive environmental program has been conducted at LLNL under the auspices of both the U.S Department of Energy and the U.S. Environmental Protection Agency. This program has focused on groundwater contamination and ground surface subsidence caused by UCG. The material presented in this paper is a summary of results from the environmental studies of UCG activities conducted by LLNL as described by Mead, et al. (1981) and supplemented by the author's experience with this program in 1980 and 1981. The following sections describe specific groundwater contamination and surf ace subsidence problems encountered during field experiments in northeastern Wyoming, and will discuss implications of preliminary findings from geohydrological investigations of a site in southwestern Washington. Finally, possible environmental control technologies that are most likely to be effective in mitigating environmental impacts are discussed.

Jan 1, 1982

By Lisa Morrison

The 11th Annual Mineral Economics and Management Society (MEMS) conference was held April10-12, 2002, in Montreal, Quebec. It consisted of a series of technical sessions. Each paper addressed the economic issues that are related to the changes that many people believe are now required in the mining industry. Some of the papers were directed at how the mining industry will handle the changes that will be required in its philosophy and operations management. Of equal importance was whether the industry possesses the toolkit necessary to effect these changes and emerge stronger from its challenges.

Jan 1, 2002

By P. Kim Carroll, D. Nick Tiffany, Doyl M. Fritz

Thunder Basin Coal Company received the 1987 Wyoming Excellence in Surface Mining Award for construction of the State's first major sediment control reservoir to be designed using the new settleable sol ids standard. Use of this standard resulted in construction cost savings of more than $250,000; reduced water quality monitoring; enhanced downstream channel stability because of more natural sediment loading; allowed simultaneous establishment of permanent waterfowl and fisheries habitat; and provided a quality recreational site. This article will address factors associated with the design and construction of that sediment reservoir and the benefits that were realized. (Note: This paper was originally published in the proceedings for the 1988 National Symposium on Mining, Hydro1ogy, Sedimentology and Reclamation held in Reno, Nevada, December 5-9, 1988.)

Jan 1, 1989

By C. H. Grant

The Dew Chemical Company has been engaged in explosives research since 1953. The incentive for this research was based on the desire to find additional markets and uses for magnesium metal of which Dow is a heavy producer. The thermodynamic calculations for explosives incorporating light metals indicate energies approximately twice that of non-metallized explosives currently being used. Early in 1960, we acquired additional patent rights from independent inventors and decided to set up a development station at Virginia, Minnesota, to conduct a commercial testing and market evaluation program with this new product. The actual manufacturing of the explosive was to take place in the bore holes. Due to the complexities involved in controlling the manufacture of the explosive in the bore hole, performance was sometimes in doubt. Furthermore, our experience indicated that the metallized explosive systems could not be evaluated by the standard laboratory methods then being used, and it was necessary for us to look for more suitable research methods. Tests were conducted on several known methods for explosive evaluation. The most promising were the Navy underwater method for energy evaluation, and a modified Livingston crater method intended to compare explosive performance in rock. After shooting over two thousand charges of eight to 60 pounds under water and in taconites and granites with many types of explosives, we have developed a metallized explosive which is now being manufactured at a pilot plant in Virginia, Minnesota, and is being evaluated commercially.

Jan 1, 1963

By C. William Parisi

Since the introduction of mechanical mining, some 35 years ago, a great deal of effort has been expended by the coal industry to solve the coal dust problem. The original concern was the possibility of a dust explosion or the propagation of a gas ignition; however, in recent years it has come to be recognized as a possible 'health hazard as well. In the middle thirties, the Pittsburgh Coal Company began an intensive study of the dust problem to determine the dust levels created by the various cycles of operation in mechanical mining and to make a comparison with those of hand loading operations. Numerous dust samples were collected with a midget impinger and it was found that dust counts varied from 38 to 268 million particles per cubic foot during hand loading and from 96 to 227 million particles per cubic foot during mechanical loading. The study indicated that the source of underground dust in coal mining could be classified as primary or secondary. A primary source is one associated with appreciable degradation of size, that is, where most of the fines capable of becoming air-borne are produced. A secondary source is one in which most of the fines have been produced at some previous operation and are in such condition that they can become air-borne. Cutting, drilling and blasting are the operations which produce the primary dust. Secondary dust is formed by operations which include; loading, transportation and discharge at transfer points. The study showed clearly that the coal cutting operation was responsible for the greatest amount of dust and that the amount of dust produced varied directly with the speed of cutting; type and dullness of cutting bits; and the distance the cuttings had to fall to the floor. The information obtained from the study enabled our company to decide on a course of action and the direction to follow. With the cooperation of mining machine manufacturers, water tanks with a 200 gallon capacity were built into the machine trucks and were provided with a pump driven by a small motor. A length of 1/2" water hose carried the water from the pump to the two water spray nozzles located at the front of the machine. Water was delivered to the machine tanks by water cars which were filled on the surface or from an underground water supply. It was during these early days that wetting agents were introduced into the water system. Our studies revealed that wetting agents did little better than plain water in the abatement of the dust problem. It was found that when using a wetting agent less water was required to obtain the same results but we could not take advantage of this fact because it was almost impossible to keep the smaller nozzles open to reduce the amount of water being used.

Jan 1, 1967

By M. David Monroe

Getting the best match between truck and haul road requires examining the cost effects of many factors. Most mines use a bottom line measure based on cost per ton of material moved. This measure focuses on the two components of truck haulage cost per ton: productivity (or performance) and operating cost. For specific tasks, productivity can be measured or predicted using either field measurement or modeling. Individual tasks can be combined to provide a larger scale, longer term net figure for total mine output. True cost is more difficult to capture. Factors are time- and task-oriented and can be influenced by a summation of factors over a truck's lifetime. For example, "allocated" costs, such as owning (depreciation) and some repair costs, are spread over long periods. Items such as fuel and tires can be tied more directly to certain tasks. This article focuses on the more direct, task-oriented factors that affect truck productivity and cost. Major factors The relationship of haul roads and trucks means that each must be examined separately to isolate the most important factors affecting performance and cost. There are many factors but the most important are:

Jan 1, 1992

By Robert W. Greene

Next month, American Commercial Barge Line Company will begin moving coal from mines on the old Camp Breckinridge property in Western Kentucky to TVA's new 2600 MW steam plant at Cumberland City, Tennessee. By April of 1973, this movement will reach a level of 7,000,000 tons per year. TVA bought the coal rights to this property from the General Services Administration in 1965 for approximately $7 million. The reserve contains about 120 million tons of recoverable No.9 coal, and about the same recover-able amount of No. 11 coal. TVA then contracted through competitive bidding with Peabody Coal Company to mine the No.9 seam through two slope shafts. The mines are about 300 feet deep and are separated by the one major fault on this property. The mine portals are approximately 3-1/2 miles apart, with the northern portal being over nine miles distant from the Ohio River (see Figure No.1). In 1969 TV A took bids on alternate methods for transporting 120 million tons of coal to Cumberland City at seven million tons per year. These alter-natives included overland transportation to the Ohio River by rail or conveyor, water transportation from Union County, Kentucky to Cumberland City, and total transportation packages from Camp Breckinridge to Cumberland City. The latter could be a joint land/water package, or all land (rail). Ultimately American Commercial Barge Line was awarded an $88 million package transportation contract to convey the coal from Camp Breckinridge to Uniontown, Kentucky; to store it at Uniontown in a quantity sufficient to allow ratable delivery to the steam plant; and to barge from Uniontown to Cumberland City via the Ohio and Cumberland Rivers.

Jan 1, 1971

By R. R. Johnson

The Hama Mining Company owns and operates The Groveland Mine near Iron Mountain, in the Upper Peninsula of Michigan. The orebody is part of the Menominee Range of the Lake Superior District. The ore (generally known as Jasper taconite) contains an average of 35% iron ranging from 28% to 39% with an overall split of 60% magnetite and 40% hematite. The variations encountered throughout the orebody require a certain amount of blending to reduce feed changes to the mill. One of the variables which affects the crushers, as well as the mill, is the range of hardness which has a low of 7.9 and a high of 24.6 as measured by the Bond Twin pendulum impact and crushing technique. Reference is made to hardness only to point out its effect on crushing and wear rate variations. Over a period of time, these variables do, of course, average out. Mining of the low grade ore started in 1959 and has operated continuously to date. Preparation of the feed for conventional rod and ball mill grinding is accomplished by three stages of crushing. Reduction of crude ore is first passed through a 54 inch gyratory crusher; then through a secondary crusher; followed by two or three tertiary crushers in closed circuit with screens as production quotas require (Figure 1). Current demand to the crushers is about 5,200,000 tons of crude ore per year.

Jan 1, 1976

By Jerry Solomon

The subjects to be examined in my portion of the session entitled "Technology of Aluminum.. Recovery" will be twofold. 1. Economics of the basic aluminum economy--supply-demand-price. 2. Specifications of aluminum products produced from municipal waste--from the secondary aluminum standpoint. It is the object of this speech to first impress everyone with the excellent long-run markets for the aluminum products from municipal waste and then to acquaint everyone with the rather liberal scrap specifications that the recycling industry can tolerate. The most important statement that can be made about the recycling of aluminum is that it is now and will be an economic necessity. This is true far many reasons; one which hit the headlines recently was Interior Secretary Rogers Morton's statement "Third-world nations could use mineral wealth not to achieve political ends but to jack up economic positions. The result could be sky-rocketing prices and dwindling supplies on world markets." There is no reason why the group of countries that supplies most of our bauxite can't get together the way oil-producing countries got together on the price of oil. (Jamaica and Surinam, are original sources of two-thirds of the aluminum used in the United States.) The worry is not so much that we will end up without the basic raw material but rather that the price might be so high that we could not afford it. So much for the blackmail reason for recycling aluminum; the supply and demand picture in both the primary and recycling sectors of the aluminum economy is far more meaningful.

Jan 1, 1974

By Donald W. Gentry

It appears that the competition for increasingly scarce international mining investment capital will continue among developing countries. Indeed, there is growing evidence this competition may be on the verge of becoming destructive and cutthroat in nature. While this may be viewed as good news by short-term, speculative investors, it could have dangerous repercussions for international minerals producers over the long-term. It seems there has been a continuous parade of traveling foreign delegations touting the virtues of mineral investment in one country or another. These pitches all contain the politically correct key words, such as macro-economic reform, political reform, privatization, liberalization of laws governing mining and related investment incentives, reconciliation of ownership and right-to mine issues, and tax reform specially tailored for the minerals sector. Unfortunately, some of the information being trumpeted is based on plans, concepts or hopes for change rather than actual reforms approved by all necessary governmental entities. In yet other situations, the information provided consists of half-truths at best. Too often, potential minerals investors, faced with metals and minerals prices hovering near their recession lows and the need to offset old, high-cost operations, desperately want to believe all they hear about investment alternatives cast in a near-utopian setting. However, the virtues being proffered for mining investment abroad do not eliminate the need for careful scrutiny of subtle variations of traditional risks associated with foreign investment that can drastically affect the economic viability of mining projects.

Jan 1, 1993

By F. W. Metzger

Coal quality control in mining and mine planning has always been important and has become even more essential in recent years due to environmental considerations. The primary consumers of the sub-bituminous coals found in the Powder River Basin of Wyoming are electric utilities that require low sulfur coals to meet government air quality regulations. Electric generating plants are designed to burn coal of a specific quality, and the supplier of that coal must be able to guarantee shipments within specified quality tolerances. Over the past several years, Exxon Coal USA and, more recently, The Carter Mining Company, a division of Exxon Coal USA have established an evaluation and development program to accurately define the geology and quality of their coal properties. This requires an adequate drill hole density so that detailed correlations of the coal seam and the lithologic sub-units, of the coal seam can be made. These units must be recognizable in the core and also on geophysical logs.

Jan 1, 1981

By R. E. Thill

An ultrasonic, pulse-immersion apparatus and method are described for determining the effects of moisture on the dynamic elastic properties of rock. The method provides an alternative approach for assessing the moisture sensitivity of rocks. Ultrasonic wave velocities are continuously monitored in immersed rock samples as a function of water absorption and time up to saturation. Moisture effects on compressional wave velocity vary as a function of the type of rock and the time and amount of water absorption. Regression analyses are used to curve-fit plots of the data and to derive empirical expressions for compressional wave velocity as a function of water content for different categories of rock. Results indicate that compressional wave velocity can be used to predict both the moisture content and its effect on strength and deformational properties of rock. These results have potential for detecting or monitoring bad roof conditions in situations where the mine rock exhibits strength degradation with moisture absorption.

Jan 1, 1986

By Yashar Pourrahimian, Magreth S. Dotto

Fragmentation by blasting is a critical process in hard rock mining. The blasting process and outcomes are highly influenced by rock mass properties and their response to higher stresses and loading rates. Each rock mass is unique, but some features affect the blast energy similarly, leading to similar outcomes. Having analyzed these features and their influence on blast results, they can be incorporated into the blast design to achieve better outcomes. This paper presents a numerical model validated by a case study from the actual mine blasts that studied the effect of rock mass properties on explosive energy production, attenuations, and overall blast outcomes. The results show that when the model parameters are calibrated based on real data, they can be used to simulate the fragmentation process and therefore be used to aid blast design.

Jun 25, 2023

By K. O. Johnson

Contaminant transport of mine and mill tailings is controlled by the hydrologic flow regime and the geochemical mobility of the contaminants. Contaminant' mobility is primarily determined by chemical reactions occurring within an interface zone between the tailings and soil The large geochemical differences between tailings and groundwater create a disequilibrium in the groundwater with respect to the soils when seepage from tailings enters the groundwater. Precipitation and dissolution reactions involving the major chemistry occur to return the perturbed system to chemical equilibrium between groundwater and minerals. Retardation of trace elements depends upon the chemical character of the groundwater and the adsorption substrates. In the case of uranium mill tailings, the mobility of contaminants is controlled primarily by precipitation/dissolution reactions which neutralize the pH, modify the Eh (redox potential), and produce highly adsorptive substrate for retardation of trace elements.

Jan 1, 1988

By K. J. Reid

A historical background of the development of automated material balance packages is presented including a summary of currently available packages and a description of the present work at the Mineral Resources Research Center of the University of Minnesota. A brief mathematical statement of the problem is given and solution techniques discussed. The problems and difficulties normally associated with material balances, both hand calculated and computer calculated are described. Several aspects of the available material balance packages as related to the "user/computer" interface are evaluated in detail. Elements of the material balance packages that affect the solutions are examined and the relative performance of the main packages on specialized problems presented. Finally, areas associated with automated material balances that require further work before computer packages can be widely used in industry are outlined.

Jan 1, 1982

By D. C. Edwards

In an age where customer service and quality drive today's industry and business, no service or product is exempt from these demands. Industry and business are streamlining everything from people to equipment and today have a heavier reliance on the performance and quality of their assets and equipment, (one of the keys to staying competitive). In the mining process industry, the centrifugal slurry pump is a key piece of equipment that keeps product moving and aids in generating revenue for its owner. The continued improvement and customer success lies in a team effort between the mining industry and the pump manufacturers. We, the pump manufacturers, need to keep improving our designs to further extend the life of our pump with fewer failures and promote to our customers proper maintenance of the pumps to continually keep unexpected failures to a minimum. Strict equipment maintenance, as thoroughly demonstrated by the military, is key to the long life and success of any piece of equipment. In the often harsh duty of the centrifugal slurry pump, maintenance is something that requires "attention to detail". No area of the pump is exempt from attentive maintenance. Here, discussions will focus on the areas of the mechanical drive end, wet end, seals, and extended pump shut down and start up. There has not been a slurry pump designed to maintain or repair itself. So in effect, each pump warrants able bodied maintenance persons to maintain them who continually observe all the rules of safety. Prior to any maintenance discussion or action, the issue of safety should always be addressed. Here, as with everywhere, the same rules apply. Work at a safe pace, note all safety precautions, use associated safety equipment and personal protective attire, observe all tagout and lockout procedures, and most importantly, be aware.

Jan 1, 1996

By J. P. Earnhardt

Recycling of such municipal solid wastes as glass containers, metal cans, and newspapers has received increasing attention recently. However, municipal solid wastes account for only 1% of the total solid waste stream in the United States. The remainder includes hazardous and non-hazardous industrial wastes. Generators of industrial wastes are facing higher landfill costs. Future liability potential, and public image concerns which are forcing them to seek innovative and often profitable solutions to minimize, reuse, and recycle their waste streams. Opportunities for the mining industry in industrial recycling include recovery of mining wastes and by-products, and utilization of mineral products for treating waste streams.

Jan 1, 1993

By Don Opacic

The disposal of sludges and other similar industrial wastes is a major problem. Liquid wastes from industrial operations, when treated, produce significant volumes of sludge which are difficult to dispose of, because of the chemical and physical properties of the sludge. In the mining industry sludge is produced from various water treatment operations, in particular mine drainage neutralization. Waste water from coal preparation plants also produces a sludge however the sludge is in fact a slurry containing clays, coal fines and coal impurities. In many areas the disposal of these sludges is producing a serious problem. Mine drainage sludge consists of a variety of hydrous iron oxides, usually ferric oxides, contaminated with other neutralization products such as calcium sulfate. The volume of sludge from mine water or mine

Jan 1, 1973