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By R. J. Gary

Why would a company in its right management mind risk a fuel conversion program on a fuel that can't burn if it's too wet or too dry, too hot or too cold, too coarse or too fine, or doesn't have enough Btu's to supplement good combustion? On December 23, 1981, two months ago, we finished our first ten years of burning lignite -- this unconventional coal. It is from that experience that I am qualified to address you today. As some of you here probably already know, my company, Texas Utilities Generating Company, has pioneered the utilization of Texas lignite for electric power generation on a large scale, and I think it is fair to say that we have done this pioneering work largely on our own. Some of us feel like Noah did when he built the arc! I have titled this presentation "The First Lignite Decision" because our company was the first to make this major decision in Texas in the mid-1960's. It was a big decision, and at the time, perhaps a bold one. When you look at the conditions that existed in the mid-1960's, you can see why.

Jan 1, 1982

By W. H. A. Timm

Lake Dufault Mines, Limited, is located ten miles north of Noranda, Quebec. Following discovery of a copper-zinc orebody late in 1961, metallurgical investigations of diamond drill core were conducted by Lakefield Research Limited during 1962 and 1963. These were followed by pilot-plant tests in May and June of 1964, utilizing underground development ore. Milling operations commenced on August 16, 1964, and reached rated capacity of 1,300 tons per day by October 1, 1964 (Figure 1). Since that time, tonnage was gradually increased to a maximum of 1,400 tons per day and since January 1, 1968, gradually decreased to the present rate of 1,100 tons per day due to an increase in the hardness of the ore. The ore milled from start-up until January, 1968, was mainly massive sulphides, consisting of a complex mixture of iron, copper, zinc and minor amounts of lead sulphides with important associated values in gold, silver and cadmium (aver- age specific gravity 3.8). From January, 1968, until the present, the ore being processed is described geologically as a boxwork of sulphide stringers of chalcopyrite, pyrite and pyrrhotite and some local dissemination in siliceous rhyolite (average specific gravity 2.9) supplemented by the massive copper-zinc ore. The limited size of the orebody and the mining method employed (open stoping by blasthole and slash and bench methods) would have made grade control from the mine difficult and expensive. It was decided to try to cope with grade variations in the mill. The resulting rapid and wide swings in mill heads, hardness and specific gravity have presented many and varied challenges for the mill personnel.

Jan 1, 1970

By Hal McVey

The logic and importance of marketing in the industrial minerals industry is generally recognized by those of us intimately involved in this industry. The illogical instances where marketing is ignored in evaluating projects or poorly implemented in operations are also well known. The interplay between these two extremes is interesting territory and is explored commencing with a logical progression of a metal mine that became an industrial minerals mine and ending with the most illogical and failure-prone decision common to the minerals industry today. This paper will demonstrate how: 1. A logical progression of marketing expertise can result in previously unseen benefits to a minerals venture. 2. Logic can turn to illogic due to market conditions and price fluctuations. 3. How operations can turn marketing logic into illogical results. 4. Short term "logic" is often illogical.

Jan 1, 1981

By S. Rajan

Familiarity with NEMA standards and the influence of the power supply on the motor-load system permits the user to make the necessary decision as to whether a standard or special motor is needed for his particular application. This paper highlights the more important aspects of NEMA standards for ac induction motors from the application engineer's standpoint and the effect of the power supply on motor characteristics.

Jan 1, 1975

By Colleen A. M. Gibbs

On July 30, 1979 New Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the decade-old National Environmental Policy Act went into effect. These new regulations replace approximately seventy different sets of agency regulations, providing some uniformity throughout the Federal government in the conduct of environmental reviews and preparation of environmental impact statements (EIS). This attempt by the Federal government at a general improvement in the preparation and quality of EIS's presents an opportunity for the mining industry to evaluate how the EIS process for mining proposals can be expedited. The environmental impact statement is often a key element on the critical path of a major mining project. Preparation of the EIS is ordinarily the responsibility of the Federal agency with primary decision-making authority over the project. Still, the proponent, i.e. the mining company, can play a major role in the process and have a major impact on the timeliness and adequacy of the effort. Typically, the Proponent will conduct (or will hire consultants to conduct) environmental baseline studies of, for example, air quality, wildlife, geology, water quality, vegetation and archaeology. These studies are then compiled into an environmental report and submitted to the agency. The agency verifies the data and incorporates them into the environmental impact statement.

Jan 1, 1979

By Rick A. Croote

The objective of the Cerrejon Coal Project is to mine and export a minimum of 15 million metric tons per year of bituminous coal from the Guajira Pennisula in Colombia, South America. Major components of the project will include an open pit mine, 150 km railroad, marine terminal for storage and shipping, and accommodations for the support personnel. This paper primarily reviews the coal handling facilities at the mine and port which will include crushers, conveyors, silos, stacker/reclaimers, and a shiploader. Of special interest is the design concept for unloading bottom-dump railcars, a programmable controller control system with automatic stacking and reclaiming, a linear-type shiploader, and 2.4m wide conveyors running at 5 m/sec.

Jan 1, 1983

By M. W. Springett

During the 1970's geostatisticians were often accused of not paying sufficient attention to geologic features in the computerised generation of ore reserves. Unfortunately this charge was all -too-often justified and the results of such studies tended to be oversimplified and failed to reveal the full potential of computerised reserve estimation and geostatistical methods. There were some notable exceptions to this trend. Techniques were described that paid a great deal of respect to the geologic characteristics peculiar to certain deposits (Rendu J-M, 1984, Barnes T. E., 1982). At Gold Fields several techniques have been developed for handling the geologic characteristics of ore bodies for reserve estimation purposes. These have developed over time and the evolution of their adoption has been a reflection of our own learning experience from the practical application of computerised reserve estimation on many precious metal s deposits. Problems Typical problems that have been experienced by ourselves and which we have learned to guard against and watch for are: ? "smearing" at geologic contacts ? confusion caused by disparate "selective mining unit sizes" and block sizes ? conflicting estimates generated by field staff using various versions of the polygonal method ? problems in generating meaningful variograms

Jan 1, 1985

"The 35th Annual American Mining Hall of Fame Awards Banquet and Fundraiser, sponsored by the Mining Foundation of the Southwest (MFSW), will be held at the JW Marriott Tucson Starr Pass Resort & Spa on Saturday, Dec. 2, 2017. This year, the Foundation will honor one living Hall of Fame inductee, two Medal of Merit recipients, four honorees from Mining’s Past and an Industry Partner for their respective contributions to the mining industry.Gary J. Goldberg will be the 2017 Hall of Fame Inductee and will serve as the keynote speaker at the awards banquet. Goldberg was appointed president and chief executive officer and joined the board of directors of Newmont Mining Corp. in March 2013. Prior to this appointment, he served numerous companies in key positions including Rio Tinto Minerals, US Borax and Coal & Allied Industries. At every appointment, he was able to improve safety concerns and reduce injury rates. While serving as chairman of the National Mining Association, Goldberg launched the CORESafety initiative and US Borax was the first mining company to receive the California Governor’s Environmental and Economic Award.The Medal of Merit will be awarded to John C. Lacy, a shareholder of DeConcini McDonald Yetwin & Lacy, P.C. and a director of the Global Law Center at the University of Arizona’s Law School. Lacy’s law practice concentrates on mining and public land law and encompasses transactional and title consideration involving acquisition of mineral rights. He played a crucial role in the revisions to the mining law of the Republic of Bolivia and the English translation of the mining laws and regulations of Mexico. Lacy’s expertise in mining law impelled the University of Arizona James E. Rogers College of Law to approach him to head the new Global Mining Law Center in 2015. The program now partners with the Lowell Institute for Mineral Resources and offers cross-listing of courses"

Jan 10, 2017

By H. P. Hatch

Ash is a material that many people leave to nature to handle. Others sometimes sweep it under the rug to be disposed of by someone else. In our business we cannot do either. In fact the American Electric Power System spends many millions of dollars in plant investment costs to collect the material, and then many more millions to dispose it. In 1965 alone the coal fired steam generating plants in., the AEP System produced approximately 2,400,000 tons of ash, enough to fill 40,000 coal cars which would extend as a single train across the entire states of Ohio and Indiana. Even though our present ash production is large, this is only the beginning when we forecast the future growth of our system. By 1980 it is estimated that our generating capacity will expand to about three times its present size, and with coal as our primary source of fuel our ash production will increase proportionately to about 7 million tons a year.

Jan 1, 1966

By Ralbern H. Murray

Typical First Year Selling Price Strip Mined Western Sub-Bituminous Coal Based [Fixed Capital (1) $600 MM Construction Loan Interest $100 Working Capital $ 30 Start-up Costs $ 30 Total Capital Requirement $760 MM Annual Costs (First Year) $M/Year Coal (2) 443,550 Operating Costs(3) 53,000 Depreciation(4) 36,500 Interest(5) 45,220 After Tax Profit(6) 34, 200 Federal Income Tax (48% Rate) 31, 570 Gross Revenue Required 245,040 (Less) By-Product Sales (18, 000) Net Revenue Required 227, 040]

Jan 1, 1975

By V. J. Hucka

Coal, which was discovered in Utah in 1849, covers about 18% of the total area. Production in 1981 vas more than 14 million tons. However, some Utah coal mines are quite gassy. If longwall face technology is applied, then a release of a high volume of methane may be expected during the mining process. Investigations on methane content have been made by use of an isothermic bubble desorbometer. The desorbable methane content of 5 m3 to 16 m3 of methane per ton of coal mined has been determined.

Jan 1, 1983

By T. P. Meloy

Current coal cleaning technology uses heavy media (HM) for the recovery of coal in particles larger than 1/16 of an inch. Through the use of float sink measurements of the feed and products to commercial HM unit operations, a selection function, sometimes called Tromp curve in the coal industry, can be computed. Since the selection function is a plot f the probability of a particle appearing in the float versus the particle density, the slope of the curve will be sharper at the point where the particle has a 50% chance f appearing in the float. Thus, the separation will be better. Fine-tuning a unit operation or a circuit of unit operations requires that the selection function be accurately known. By current practice, it is difficult to obtain an accurate measure of the slope because, when the selection function is plotted versus density, the data forms an S-shaped curve which lacks data points near the 505 point of the curve. This lack of sensitivity in measuring the slope means that small recovery improvements cannot be detected; thus, only large improvements are measurable. Since most engineering improvements are small when individually considered, but large when aggregated ever many small improvements, this lack of measurement sensitivity rules out the slew march toward improved efficiency. This paper presents a method of analyzing heavy media selection functions resulting in a far more effective measure of the selective function slope. Furthermore, this improved method is applied to a number of industrial coal cleaning plants for both heavy media and heavy media cyclones. Using the work of Hudy (1968), and Deurbrouck and Hudy (1972), selection functions for individual unit operations in each plant are calculated as a function f particle size as well as density.

Jan 1, 1982

By Hiroyuki Abé

This paper is a review of research and development on geothermal energy extraction in Japan especially on hydraulic fracturing. First recent geothermal developments in Japan are outlined in Part I. An increase in the production rate of geothermal wells may be highly dependent on the geothermal well stimulation technology based on hydraulic fracturing. The hydraulic fracturing technique must be developed also for geothermal energy to be extracted from hot, dry rock masses. In Part II, the research on hydraulic fracturing and field application are reviewed.

Jan 1, 1982

By Wei Li

Carbothermic reduction kinetics of ilmenite concentrates catalyzed by sodium chloride and the microwaveabsorbing characteristics of the resulting reductive products were investigated; the reduction degree of the reaction was deduced to be . Results show that the activation energy is 112.03 kJ/ mol when NaCl is used as catalyst, lowering to 23.11 kJ/mol for the final stage activation energy using sodium silicate as a catalyst. There is a sharp change in the reduction rate constant at temperature ranges of 1,223 K - 1,273 K and 1,373 K - 1,423 K. Microwave-absorbing characteristics of reductive products were measured by the method of microwave cavity perturbation. It was found that microwave-absorbing characteristics of reductive products obtained at temperatures of 850° C, 1,100° C and 1,150° C show sharp changes. Through X-ray diffraction (XRD) characterization, it was found that the formation of Fe occurs at a temperature of 900° C during the reduction process of ilmenite concentrate. The decrease of FeTiO3 content results in the decrease of microwave-absorbing characteristics, while the increase of Fe content gives rise to the increase of microwaveabsorbing characteristics. The decreasing trend is larger than the increasing trend, which is the main reason for the sharp changes in the microwave-absorbing characteristics of reductive products at the temperature range of 850° C to 900° C. When the decreasing trend is smaller than the increasing trend, it becomes the main reason for the sharp changes in microwave-absorbing characteristics of reductive products at the temperature range of 1,100° C to 1,150° C. Kinetics results show that sodium chloride can catalyze the carbothermic reduction of ilmenite, and microwave-absorbing characteristic investigations indicate that microwave heating can be used in the carbothermic reduction of ilmenite.

By W. T. Reid

Analysis of the energy resources available in the United States confirms that coal will be needed to satisfy the future energy needs. The trends in the market place, particularly economic and political, suggest that the bulk of the coal will be consumed for generation of electricity. The utilization of coal to produce electricity will require technical solutions to the variable characteristics of coal and ash, development of methods to improve coal quality, and public acceptance of the cost of compliance with environmental standards.

Jan 1, 1983

By Colin D. Jardine

Rapidly increasing energy costs and more rigid customer quality requirements necessitate improved control of pelletizing processes. With the introduction of dedicated microprocessor-based controllers, sophisticated control strategies are now possible. A recent application of this technology at Carol Project has resulted in fuel savings, improved pellet quality, and standardization of operating procedures. This was accomplished with no production loss by the use of a "building block" approach to design and equipment selection. Details of this approach and the results obtained are described.

Jan 1, 1982

By P. R. G. Brandão

In this investigation, the differences in the absorption spectra of etheramines, fatty amines and condensates, mostly present as acetates, from several suppliers are characterized by means of infrared spectrometry. Sharp differences were observed in the absorption spectra of three types of amines and derivatives. Etheramines show a characteristic and well-defined peak at 1,114 cm-1. This peak is due to the ether C-O group and differentiates etheramines from the other classes. The absence of such a peak indicates that the species is not an etheramine. The distinction between condensates and fatty amines is made by the presence of a sharp peak around 3,200 cm-1. This peak is probably due to the proximity of the N-H amine groups and C=O carbonyl groups in the amide portion of the condensate's molecule and by different and better-defined bands in the 1,800- to 1,500-cm-1 range. The flotation performance of these amines was evaluated by means of the laboratory-scale flotation of an itabirite ore. The etheramines proved to be the most effective collectors for this system. Monoamines presented better performance than diamines for the ore under investigation.

Jan 1, 2002

By Heather Wright

Shovel operators are one step closer to having a better tool to operate and monitor their equipment. The development of a unified shovel interface is proceeding into phase three, focused on producing a standard application programming interface (API) for connecting onboard devices. This solution will positively impact safety, performance and productivity, and is the result of collaborative work driven by the Global Mining Standards and Guidelines Group (GMSG). Proof of concept revealed During the spring of 2013, Peck Tech Consulting was engaged to develop the working proof of concept (POC) software implementation, which integrates multiple vendors? systems into a single interface using one-to-two displays. As a result, the GMSG developed a functioning, manipulatable, unified shovel interface proof of concept and unveiled it at the World Mining Conference in August in Montreal. The proof of concept effectively provides a unified operator interface that pulls together the many divergent systems onboard large shovels.

Mar 1, 2014

By George C. Trevorrow

It is a pleasure to appear on this program and discuss a subject which is of particular interest to me. In my regular duties as Safety Director of Bituminous Coal Operators' Association, I am called on by member companies to discuss matters affecting face ventilation. As a member of the Joint Industry Safety Committee, as I will later describe, I have a part in processing requests for the use of auxiliary fans for face ventilation. The use of auxiliary fans in bituminous coal mines for this purpose came into rather wide use in the late. '20's when conveyor mining was introduced. In this application, the equipment consisted of a chain conveyor with a face chain conveyor parallel to the face on which the coal was loaded by hand and, in turn, was discharged onto the room conveyor and thence to a loading point on the entry at the mouth of the room. Another method was to use a shaker conveyor with a duckbill which was maneuvered across the face of the room from which the coal was loaded and transported by the shaker to the loading point. In either case the equipment did not readily lend itself to driving crosscuts or breakthroughs with the result that rooms were driven to depths of 250 or 300 feet without adequate means of ventilating the face area with the main split of air. It was, therefore, necessary to use other means of ventilating this area as the rooms were being driven and during retreat work if pillars were extracted. Auxiliary fans of the blowing type were utilized for this purpose. They were of very small capacity using small diameter tubing. By the time the room was driven half way to its projected limit ventilation was very poor or practically nonexistent. To compound the problem the fan was usually set up at the mouth or neck of the room and in many cases the intake air to the fan was the return air from the room. It is small wonder, therefore, that there is on record 12 cases where auxiliary fans were given as the cause of explosions. In 9 of these occurrences, arcs or sparks from open-type motors or accessory equipment on these fans were given as the primary ignition source. They fell into such ill repute that in a number of cases they were blamed as the ignition source even though smoking was strongly suspected as the primary cause.

Jan 1, 1967

By Fred L. Myers

The use of finite element programs for evaluating large grinding mill shells is becoming increasingly popular. However, large scale, detailed analysis can become a burdensome task when one is required to manually prepare the necessary data to be entered into the program, while evaluating the voluminous results is even more devastating. Although available computerized finite element analyses can reduce computation time from years to months or even weeks, additional pre and post processors can reduce the time for data preparation and result evaluation to hours, while simultaneously reducing the probability of human error. Examples of the uses of these processors are presented as well as typical modeling techniques.

Jan 1, 1979