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By Jack R. Miller

This session has been organized to suggest to you that the development of direct reduction is important to the iron ore mining and coal mining industries. The papers presented this morning will include a discussion of the costs of making direct reduced iron (DRI), the iron ore and coal supplies needed to produce DRI, the financing of direct reduction (DR) projects and, probably most important, the impact of the DR development on the iron ore and coal industries. For starters, this opening presentation offers a brief statement about DR practice and DRI, under the title that should surprise no one: "Direct Reduction: What Is It?" There is always the chance? that a brief statement may become long and complicated. But, by mixing some slides borrowed from Hal Lownie with a larger number of photographs accumulated from other sources, I hope to avoid such pitfalls.

Jan 1, 1978

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 T. J. Lutz, L. Yan, J. R. Srednicki, J. A. Yonkey, G. T. Homce

"Federal regulations require the installation of refuge alternatives (RAs) in underground coal mines. Of the in-use RAs, over 95% are mobile RAs with the remainder being built-in-place (BIP) RAs. Heat/humidity buildup has been one of the major concerns with mobile RAs. For BIP RAs, however, there is a lack of in-mine heat/humidity test data to determine the extent of heat and humidity buildup. To quantify heat/humidity buildup in BIP RAs, the National Institute for Occupational Safety and Health (NIOSH) performed a series of heat/humidity tests on a 60-person BIP RA with and without a borehole air supply. At various times during the year, tests were performed with cooled, heated, or unconditioned borehole air to examine how various outdoor temperatures may affect the thermal conditions inside a BIP RA. The results show that the air supplied to a BIP RA may require heating and cooling, depending on the outside air temperatures and the temperature of the mine. For example, during tests with an external ambient temperature above 70°F and a humidity that reached 90 %RH, providing 55°F dew point air was able to keep the internal apparent temperature below the mandated 95°F. Results for each test case are presented. INTRODUCTION The Mine Safety and Health Administration (MSHA) has required the installation of refuge alternatives (RAs) in underground coal mines since 2008 [1]. MSHA requires that RAs provide an environment with breathable air for entrapped miners for a 96-hour period. Heat buildup inside an occupied RA is a serious concern. Without a means to dissipate the heat and humidity generated by the occupants and the carbon dioxide scrubbing system, the temperature and humidity inside RAs could lead to severe discomfort or heat stress depending on the mine ambient temperature before and during occupation of the RA. In its 2006 report, the West Virginia Mine Safety Technology Task Force recommended an apparent temperature limit of 95°F for RAs [2]. In 30 CFR 7.504, MSHA specifies a maximum apparent temperature of 95°F inside an occupied RA [3]. The apparent temperature is calculated using both air temperature and relative humidity [4]. To determine if their RAs meet the apparent temperature limit, RA manufacturers have been performing 96-hour-long heat and humidity tests in laboratories. During these tests, a heat input of 117 W (400 BTU/hr) per person is used to represent the metabolic heat of a single miner [2]. The heat generated by the RA’s carbon dioxide system is also accounted for in testing. To account for this heat, 50 W (170 BTU/hr) of heat per miner is used for a lithium hydroxide scrubbing system, or 30 W (100 BTU/hr) of heat per miner is used for a soda lime scrubbing system [5]. In these tests, air velocities around the RA are minimized to represent the worst-case scenario of an interruption in mine ventilation that might occur in a mine disaster."

Jan 1, 2017

By G. P. Salas

I.- In order to keep pace feeding its fast growing population, Mexico with only about 20% of its surface suitable for intensive agriculture, will need the application of modern foodgrowing techniques. To assure greater crop yields it will be necessary to apply more fertilizers than used at present (yearly average of 29 Kgs/hectare)** For its fertilizers production Mexico still depends mostly on imports of phosphate concentrates from Florida, U.S.A., Morocco and Spain. To reduce or eliminate this dependence on foreign providers, the Consejo de Recursos Minerales -a Federal Government exploration Institute- started in 1974 an exhaustive exploration program for phosphate deposits more amenable to commercial exploitation than the phosphatic limestones contained within the La Caja Formation of Upper Jurassic, found along the Sierra Madre Oriental. After studying literature on the origin and deposition of marine phosphate and visits to deposits in Florida, U.S.A., the Baja California peninsula was selected as most favorable for starting this program because of its geologic and sedimentary history and also for its geographic location, where the cold California and warm Counterequatorial currents meet. Exploration activities executed by FORNOS, S. A. (1956) led to the disco very of low grade phosphate (3 to 5% P2O5) in the recent beach sands along the Bahia de Magdalena (Fig. # 1). In his doctoral thesis Bruno D'Anglejan Chatillon (1965) reports the presence of nodular phosphate on the continental shelf, between Isla Margarita and the Vizcaino peninsula. He estimated reserves of up to 1.5 million tons. A Mexican-American marine exploration company attempted in 1966 the evaluation of this deposit with negative results.

Jan 1, 1978

By A. Johnson

When are SMART transmitters the smartest choice? To answer this question requires a closer look at SMART transmitter technology. It is necessary to understand this technology in order to recognize how it can best be utilized to give the greatest value for the application. And, once the decision to buy transmitters has been made, it becomes a question of whose SMART transmitter to buy. For, although the under-lying technology is similar, the differences that exist in how the technology has been implemented can make a dramatic difference in the end result. What prudent users of SMART technology do is to analyze their needs by application before making their buying decision.

Jan 1, 1988

By Silvia Misk, Cristina Araújo, João Felipe Costa, Roberto Rolo

Linear estimation methods are widely used for resource evaluation. Among the existing linear estimation methods, ordinary Kriging (OK) was accepted as the best estimator to determine the average ore grade of each block. However, OK is inadequate for modeling small blocks in relation to data spacing, resulting in over-smoothed models. In this study, the results of the recoverable resource from the short-term model are compared to estimated models generated by the traditional method, i.e., OK, and non-linear methods. The conclusion is that non-linear methods improve the accuracy and precision of the long-term model when compared to the model generated by OK.

Jun 25, 2023

By J. A. Luppens

Five years ago, Phillips Coal Company decided replacing mainframe/workstation programs with a new package of PC software was clearly the best solution for computer reserve modelling. The system chosen was actually three programs distinguished by their power, cost, flexibility and integration, and ease of learning and use. Phase I involves the use of the "StratiFact" program for borehole data management and seam correlation. This phase is probably the most neglected, yet critical aspect of reserve evaluation. Phase II employs the "PC/Cores" package for modelling and volumetrics. Phase m is "PC-Cut" which provides mine planning tools including an automated cut generator.

Jan 1, 1996

By V. A. Kharchenko, V. M. Yeremeev

INITIAL PRECONDITIONS To solve tile problem of using the potential reserves of the different coal ranks efficiently (the coal reserves being many times superior in quantity to those of natural gas and oil) one must realise an integrated estimation of the coalfields' and coal deposits' reserves. The actuality of this problem increased especially in the recent years, when the Russian coal industry is being restructured. A structural reorgaisation of this industry, in order to in- crease its efficiency, covers a large spectrum of social and economic problems, comprising a withdrawal from mining the coal reserves that are unsafe from the standpoint of economy and labour protection. According to the information supplied by the 'Rossoogol' company, the Russian coal industry, accounting for abut a fifth of the world coal reserves, has a rather unsafe resource base, for about 5% of the reserves involved in mining do not correspond to the world practice conditions, regarding the coal grade, thickness, geological conditions, proneness to coal and gas outburst hazards. These concern first of all the Moscow, Kizelovsk and Donetsk coal basins, the Prokopievsk-Kiselevsk district of the Kuzbas basin and several other coalfields. Thus, the problem of efficient potential coal reserves' utilization calls for a paramount solution of two basic problems, namely: a) a comparative coalfields' and sections evaluation, and their ranging, in accordance with their industrial importance; b) choosing the 'active' reserves good to be efficiently mined under the present-day conditions. PRINCIPLES OF EVALUATION The investigations that had been carried out make it possible to formulate the following basic principles of the coalfields' reserves' estimation (or assessment). 1. The necessity, possibility and expediency of coal reserves' industrial exploitation are determined by a set of natural, technical, technological, practical, economic, environmental and social factors, thus calling for an integrated and gradual approach to problem solving. 2. One cannot consider the results of same reserves' estimation as being invariable because the former depend both upon constant (mainly natural) and market demands for different grades of coal (those of different power engineering and technological situations), capital investments, material and labour resources, economic (price-forming), technical, technological, environmental and other factors. 3. The rational size and sequence of the operating mines' and reserve sections' resources' involvement into mining depend upon the final aim of posing the problem, whose variants may be (the corresponding limitations being considered) providing for a maximum run-of-mine output (these essentially featuring the past stages of the industry's evolution); providing for a maximum efficiency, measured possibly by the specific or absolute indices of profits an expenses, labour productivity e. al. ; providing for a maximum extraction (maximum integrate utilization) of the known reserves. In this case an important park goes to the economic evaluation (or assessment) of useful application of the by-products being extracted (methane, mine water, rack) compared to the expenses necessary for their utilization. Regarding the steam coal (posing the problem any way it be possible), and extreme limit to the absolute non-efficiency of the coal reserves' exploitation may be posed, using the proportion of energy obtained from the possible amount of the coal to be extracted to the energy consumption necessary to extract, prepare, haul and consume this amount of coal. 4. The most reliable and efficient solutions providing for opening the reserves can be obtained for group of mines, rather than at the level of an individual mine section or an individual mine because it is only in the former case that the possibilities to re- distribute the expenses necessary to develop the good for mining and worse sections and seams can be realized to the greatest extent. Therefore the prospective approach to be considered is the one providing for an integrated organization and choice of the optimum combination of the variants of the ways to use the mines in operation and the free sections of the region in order to satisfy the growing up requirements for coal rather than the one providing for individual mine sections' resources' evaluation. 5. The future possibility and expediency of coal reserves' industrial exploitation will depend upon the prospects to implant at the mines in operation and reserve sections new engineering and technological elements and coal extraction technologies which may essentially change the actual idea concerning the coal reserves worth of being developed in an efficient way. For example, reserves not available to be exploited using conventional coal extraction technology may be regarded as potential resources for in situ gasification, e. g. the operating mines' reserves (non-commercial and non-mined commercial ones), balance and outside balance reserves of the free sections having proved not available to be mined using conventional coal-extraction technologies, as well as the non-extracted reserves of the abandoned and closed mines.

Jan 1, 1996

By R. R. Givler

Since the 1860's the good ole days, oil has been nozzle fed to burners under pressure atomizing the oil into droplets -- 1960's has produced vaporized oil that burns oil with the flame color and consistancy of gas -- If you can tell the difference by looking at the flame, gas or oil I?ll buy the lunch. First, we must ask, "Why all the excitement about Blue Flame?" This question is best answered by you after you have studied the principle of operation and see the result. I will attempt to explain both of these so that you can draw your own conclusions.

Jan 1, 1975

By D. B. Stephens

Milling operations throughout the world have created vast amounts of waste by-products, or tailings, which are often disposed on the land surface. The wastes may be disposed behind dams, on untreated ground, or on compacted clay or synthetic liners of impoundments and trenches. Often one of the principle concerns of environmental regulatory agencies is whether seepage from the waste pile could move through the vadose zone to the water table and possibly contaminate an aquifer. The seepage may be generated by the drainage of liquids initially deposited along with the tailings or by infiltrating meteoric water which leaches solutes from the tailings. The purpose of this article is to discuss some of the commonly held assumptions regarding storage of seepage wastes in the unsaturated zone. The significance of recent studies of water movement in dry climates which pertain to tailings site selection will be presented. The paper is relevant not only to seepage from impoundments at mill sites, but to many other fluid waste impoundments as well in part this article reinforces earlier work by Stephens and Siegel (1980) and an excellent review paper by McWhorter (1985). The present report addresses considerations in porous media; for a discussion of the effects of fractures and anisotropy in the unsaturated-zone, refer to the paper by McWhorter (1985).

Jan 1, 1985

By Gennaro G. Marino

This paper summarizes and evaluates data on mine subsidence ground movements and associated damage for houses in Illinois. Based on the data collected, the response of homes to subsidence ground movements is expressed in terms of repair costs. A damage criteria is then proposed that relates the ground movements and damage levels. The data were collected as part of a comprehen¬sive study performed for the Illinois Abandoned ?Lined Lands Reclamation Council, A -M-RC, by the Civil Engineering Department at the University of Illinois, and probably will be published in late 1934 by the council. The study concentrated its efforts on surface ground movements and the effects to houses over abandoned room and pillar mines. The resultant surface subsidences are commonly dish or bowl shaped and are termed sags. Method of Analysis The steps in analysis used to arrive at the proposed damage criteria are: 1. Canvas and rap subsidence damage in houses, 2. Assess the associated ground movements, 3. Estimate the damage repair cost, 4. Develop a damage/repair level classifica¬tion, 5. Correlate the associated ground movement, damage/repair level and home construction type, 6. Propose a damage criteria.

Jan 1, 1984

By Kot F. Unrug

When reading different studies discussing trends in coal mining, it appears that a substantial expansion of output by the year 2000 is predicted, even in the most pessimistic forecasts. Depletion of shallow, easy-to-mine deposits is only a matter of time, and the future average mining depth will increase. The proportion of slope to shaft mines operated during the next decades will change in favor of the shaft mines. Since an increasing amount of shafts in new nine developments seems to be inevitable, it appears appropriate to focus more attention on shaft design criteria. Some valuable papers have recently been published (1) that emphasize geotechnical aspects of shaft design. In the discussion that follows some other aspects of design criteria will be evaluated.

Jan 1, 1984

By Yeonuk Choi, Gus Van Weert

cyanide control in effluents is becoming a critical environmental issue for the gold extraction industry. Silver impregnated carbon removes free cyanide effectively to the ppb level from solution in high throughput columns. By re-calcining the cyanide saturated carbon, the impregnated silver is restored to activity and the cyanide destroyed outside the effluent stream. Many gold mills already have an activation kiln on site, which could make retrofit relatively easy.

Jan 1, 1993

By Håkan Stille, Kjeld Boye-Møller, Lars Lundström

BACKGROUND Forsmark Power Station is a nuclear power plant under construction at the Baltic abt 120 km north of Stockholm. Investigations on the Site were started in 1969. Areas were reserved for a maximum of 6 units of which the buildings for two of them, Unit 1 and 2, were nearly finished in 1976, when the investigation for Unit [3], here presented, was carried out, cf Fig. 1. [ ]

Jan 1, 1979

By Russell Dittrich

The Kinross DeLamar Mine has been operated for more than 17 years producing precious metals doré from ores, principally silver bearing with associated gold coproducts. In late 1995, the Stone Cabin ore body was commissioned and the site began a phased shift from silver dominance to gold dominance. The Knelson concentrator was selected to remove gold from a portion of the cyclone under- flow stream in the grinding circuit.

Jan 1, 1998

By Donald C. Moore

Asamera Minerals Cannan Mine has been producing a 170 g gold/tonne (5 oz gold/ton) siliciaus flotation concentrate since July 1985. Flotation concentrate is shipped to a smelter for gold recovery. Numerous processes have been investigated to economically produce bullion on site. This paper describes the laboratory and pilot plant test results of a bacterial assisted oxidation of the refractory minerals. Economic comparisons with autoclaving and roasting processes are included.

Jan 1, 1989

By J. Rao Mokka

Extensive exploration has resulted in delineation of a massive sulfide district on the north flank of the east-central Alaska range. The district covers approximately 400 square miles and contains numerous stratiform; transported and some replacement type sulfide deposits ranging in size from less than 1 million tons to 20 million tons. Five types of ores were sampled for the study. Mineralogical analysis revealed that the minerals are too fine grained for conventional grinding and beneficiation. Hydrometallurgical studies were con-ducted using ferric chloride as a lixiviant. Ore microscopic studies as well as electron microprobe analyses of minerals in the raw samples and leach residues explained the low recoveries for certain elements as well as sources of impurities that need to be eliminated from the process streams.

Jan 1, 1991

By Brian F. Taylor

The Mexican fluorspar industry is faced with and will face serious problems, some of their own making and others beyond their control. However, they still offer the most secure source of fluorspar for North American' consumers. Since 1975, even in light of declining markets, they have, increased then production capabilities' as shown in Table #1. In analyzing Table #1, we note that Compania Miners Rio Colorado has closed down due to their ore reserves being exhausted. Fluorita de Rio Verde expanded their acid grade fluorspar capacity in anticipation of additional North American business. Campania Miners Las Cuevas presumably increased capacity to meet their North American contractual commitments and to supply their own hydrofluoric acid plant (Fluorex) at Juarez, Mexico. Historically, the Mexican fluorspar industry has relied on the United States as the mainstay for their sales. As shown in Tables #2 and #3, the Mexican share of the United States market has moderately decreased. However, as noted in Table #4 the volume loss is substantial as explained below.

Jan 1, 1985

By Elgin D. Bell

Within the next, year or two, Western Canada should overtake Mexico and France. to become the worlds second largest producer of elemental sulphur, surpassed only by the United States, By 1965, it should produce about 25% of the world's total elemental production and, about 10% of sulphur produced in all forms. In 1952 Alberta had but one small sulphur recovery plant. By 1962, it had fifteen plants with a total designed capacity of almost 6,000 long tons of sulphur per day and actual production of almost one million long tons per year. This decade of dynamic growth was the result of Alberta's rapidly developing natural gas industry. More particularly it was the result of approval in 1960 to export natural gas in large volumes into the United States. Prior approval to export gas from Alberta to eastern Canada and relatively modest volumes to the U. S. had resulted in the construction of several plants but none were of the scale required to serve the U. S. market.

Jan 1, 1963

By S. A. Bunk, W. P. Wood

In the early 1980's BHP identified several potential gold deposits in West Africa. One of these deposits was located in Mali, near the village of Syama. As a result of extensive explo­ration activities, an oxide ore as well as an underlying sulphide ore was identified. After agreement with the government of Mali was reached the development of the deposit was undertak­en. The plan for the development of the mine included the treat­ment of the oxide ore followed by the treatment of the underly­ing transition and sulphide ore. The development of the deposit was extremely aggressive. Following the approval of the project in early 1989, engineer­ing was started, equipment purchased sitework was started, and the first ore was introduced in December of 1989. This was accomplished in spite of the difficulties of the site. These diffi­culties included: • remote site location without air or road or water access • no existing infrastructure including water, power, or communication • high health risks • limited construction and manufacturing support in West Africa The operation began with a conventional crushing/grind-ing/CIL/elution and electrowinning facility. The facility was designed to treat 2000 metric tonnes of ore per day. After start­up in December of 1989, the operation was improved to the point that plant throughput was averaging nearly 3000 tpd and running at 92 to 93% availability.

Jan 1, 1996