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By Legett Garrett

Texas Utilities Generating Company (TUGCo) surface mines lignite for use as a boiler fuel at mine mouth generation stations. Currently, the annual lignite production requirement of approximately 28 million tons necessitates mining across approximately 1,600 surface acres each year. The mining operations, located in Freestone, Panola, Titus, and Hopkins counties, Texas, have drastically disturbed some 13,000 surface acres to depths of up to 110 feet since initial startup in 1971. The TUGCo mining philosophy, a commitment made prior to initiation of mining operations and prior to any mining regulations, includes a return of mined-out land to private ownership in the most useful state possible. In the areas of TUGCo operations, the local economies are based upon agricultural production. Historic land use surveys have typically shown a trend from row crop production to pastureland for cattle production. During the 1960?s, the percentage of acreage devoted to row crop production approached zero with respect to the total acreage devoted to agriculture. TUGCo reclamation operations have therefore emphasized restoration of land to a state that is favorable to cattle production

Jan 1, 1982

By G. Barbery, P. Dauphin

"In order to obtain reproducible and reproducible results in batch flotation, researchers have tried various approaches, from normalized testing, to modifying existing cells, and even designing new machines. The paper reviews the basic concepts that must be fulfilled in a laboratory flotation machine, and present the FLOTOMATEC design, which results from five years of testing and development. In addition to providing accurate measurements of air flowrate, power consumption, agitation speed, the cell eliminates most operator induced errors. Results of experiments comparing FLOTOMATEC to a conventional cell, as well as reproducibility tests are given. Introduction The use of batch flotation machines in mineral processing research and development is very common. These machines have been used for many years without almost any change in their design, instrumentation or automation. Various authors since Raffinot (1960) have criticized the available designs, especially with respect to the large errors that are introduced by the manual mode of operation. Barbery et al. (1986) have presented a review of the problems involved in laboratory testing in flotation research.Batch laboratory machines should have the following characteristics:"

Jan 1, 1989

A hidden asset in most exploration and mining activities is data. Common practice involves the spending of large amounts of money to discover, define and prove the viability of a mining project. Some organisations have used operations research analysis and internal costing methods to allocate a value to their data and to compare the costs of data maintenance to other more tangible activities like plant and equipment maintenance. Those organisations, which do not undertake such an analysis often, have little knowledge or understanding of the extent and the worth of their data. Often the organisations lack of knowledge and understanding of the data is indicated by their failure to fully exploit or realise their opportunities. The focus of this paper is to discuss new technologies that optimise the management and security of collected and derived data. The technologies discussed are components of the software systems acQuire and MineSight.

Jan 1, 1999

By B. S. Butler

STUDY of the ore deposits of Colorado has disclosed, in numerous places, sharp changes in both mineralogy and metal content of the primary or hypogene deposits with change in depth. A clear understanding of the meaning of these changes is requisite to form intelligent conclusions that can be applied in the exploration of such ore deposits. This paper is an attempt to set forth some of the geologic and chemical relations of minerals that bear on this problem. The effect of the differing electrode potentials of elements on the order of oxidation and on the order of displacement of one metal by another metal in supergene sulfide deposits has been studied for many years by several investigators. The results all agree rather closely with the original Schürmann series of replacability of metal sulfides, as Wells has shown.1 So far as the writers are aware there has been little attempt from the geologist's viewpoint to correlate the electrode potentials of the elements, other than those of the common metals, with the positions and mode of combination of the elements as found in ore deposits, and in particular in hypogene deposits. Wells2 discusses electrochemical activity between solutions and certain ore minerals and mentions the possibility of its effect in precipitation reactions.

Jan 1, 1929

By Gary Repetto

Hiring trends in the construction materials industry have remained steady through the years, with some seasonal and geographical variances. However, after several years of a depressed market, the base metals industry has begun to actively hire only over the past two years, due to the continued strength in the prices of copper, lead, zinc, molybenum, etc. The expanding precious metals industry, which for the most part escaped the depressed markets of the mid-1980s, actually preceded the base metal companies in hiring of engineers and operations personnel. The coal industry has not seemed to rebound much from the cutbacks of the early 1980s. And the uranium industry, which began its decline a year or two earlier than the other mineral industries, has remained nearly nonexistent in the United States. In nearly all of the mineral industries, new hires have been mostly in the engineering and operations areas, not exploration.

Jan 1, 1990

By R. P. E. Hermsdorf

THE electrolytic refining of metals for the removal of undesirable impurities has become a recognized necessity in the nonferrous field. Copper, lead, zinc, nickel, silver and gold have been produced in this manner for years. The United States Metals Refining Co., realizing that considerable quantities of lead and tin could be made available to the trade if a satisfactory method of purification of these metals could be established, decided to investigate the possibilities of electrolytic solder. In cooperation with Dr. Edward F. Kern, of the School of Mines at Columbia University, the company developed a process of electrolytic refining of lead-tin alloys using a tin-lead fluosilicate electrolyte. A pilot plant was installed in November, 1927, and the commercial unit was put in October, 1929. Since that time thousands of tons of electrolytic solder have been produced in this plant and consumed by all branches of industry that use solder.

Jan 1, 1936

B. R. Coil (Electrical Installations at the Miami Mine are Cheaper with Flexible Cable, P. 356) was born in Higginsville, Mo., and attended McKinley High School and Missouri School of Mines. He received a B.S. in mining engineering. Mr. Coil has worked for the Braden Copper Co., Rancagua, Chile as junior engineer and foreman. He was employed by Miami Copper Co. as a jigger boss, shift boss, development engineer and mine foreman. He worked as mine superintendent and general superintendent of the Castle Dome Copper Company, Inc. Mr. Coil may be reached at Box 100, Miami, Ariz. He is an AIME Member. Mr. C. R. Ross was co-author with Mr. Coil in the preparation of this paper. His paper covers the present installation of electrical equipment in block caving stopes along with background data. In this paper he has given one solution to wiring problems in heavy stopes.

Jan 1, 1952

By Fernando Hernández Polanco

Transportation and handling metals and alloys from mills to consumption factories as well as dosing in conventional processes with ingots and scrap has always been considered a complicated activity with high operating costs. Several manufacturers of ferroalloys willing to solve these problems have chosen an alternative for their products that can be used to secure, during transport and dosage in the processes to making special steels, with more efficient consumption of ferroalloys. The trend for the production and sale of ferroalloys is to provide the product in the form of granules packed in bags or in bulk. In this paper we will show you how the granulation process was developed and rapidly adopted the ferroalloys industry as an effective solution to reduce operating costs, create cleaner and safer working environments.

Oct 30, 2017

By Charles A. Ashburner

The existence of natural gas-springs in Pennsylvania and the adjoining States west of the crest of the Allegheny Mountains was known to the earliest settlers. Possibly the first gas obtained from a well was at Fredonia, Chautauqua County, N. Y., where a well was sunk on the bank of Canadaway Creek, near the Main Street bridge, in 1821, and sufficient gas obtained for 30 burners, the inn having been illuminated by the gas when General Lafayette passed through the village about 1821. In 1858 another well was drilled, which supplied 200 burners. A still larger one was drilled to a depth of 1200 feet in 1871. According to Mr. E. J. Crissey, Secretary of the Fredonia Natural Gas Light Company, the average monthly supply of these wells in 1880 was 110,000 cubic feet. Since 1859, when the drilling of oil-wells in Western Pennsyl-

Jan 1, 1886

By J. Gotor, C. Frias, E. Delgado

The Iberian Pyrite Belt (IPB) is one of the world's largest reserves of primary sulphides containing base metals (Cu, Zn, Pb), precious metals and some special metals such as indium. Estimated resources are over 1,500 million tonnes of volcanogenic massive sulphide ores. From 1980´s Europe lives the decline in its mines mainly motivated by the low price of the metals. One aspect that contributed equally to this was the ecological disaster produced by the discharge of more than seven million tonnes from the tailings dam of Boliden-Apirsa (Aznalcollar) in 1998. Today the situation is different; the companies present in the IPB have given evidence that it is possible to reconcile mining projects and care on the environment, and the regional authorities are opening a public tender to re-start Aznalcollar mine. A new challenging era has been started at this Spanish/Portuguese mining area. This paper presents the results and preliminary economics of a project devoted to IPB primary sulphides processing through different technology approach, e.g. conventional selective flotation against bulk flotation or mixed metals flotation combined with hydrometallurgical processing.

Jan 1, 2014

By H. Wesley Peirce

Arizona embraces portions of two major western-U.S. physiographic-geologic provinces and a smaller, local one. These exert fundamental control over the geologic framework and associated earth-material resources and potential. The Mogollon Rim diagonally crosses the State and separates the Colorado Plateau Province to the northeast from the Transition Zone and Basin and Range Province to the southwest. More than 90 percent of the population, production of nonfuel minerals, agricultural land, and water resources are in the Basin and Range part of the State. In 1981 Arizona was ranked number one in the Nation with respect to the value ($2.56 billion) of nonfuel-mineral production. About 8.2 percent of this amount ($212.9 million) can be attributed to nonmetallic (industrial) materials. Although a diversity of nonmetallic substances is produced and some are exported, the bulk is utilized within the State and is directly related to market growth. Since 1950 there has been a fourfold increase in Arizona's population, a concomitant twelvefold jump in sand-gravel production (tons), and a twentyfold increase in "stone" production. New industries developed during this time include cement, salt (and storage of liquid petroleum gas products in solution cavities in salt), zeolite, hydrofrac sand, vitrified clay pipe, crushed marble products (teed additive, pool sand, roofing granules, etc.), and "rock" wool. Most of these newer industries serve out-of-State as well as in-State markets. In 1981 at least 225 industrial mineral or rock deposits were being worked to produce about 10 tons of material per Arizona resident per year. In 1980 the relative values of basic industrial minerals produced in the State, by major group, were cement and lime (51.6 percent); gravel (26.5 percent); sand (11.8 percent); stone (4.6 percent); and others (5.5 percent). Detailed knowledge of the nonmetallic rock-and-mineral content of most Arizona ranges and basins is lacking. Exploration opportunities in this sun-belt growth region appear encouraging.

Jan 1, 1987

By Potter G. M.

Ore-dressing tests were conducted on a sample of ore submitted by the Richmond Hill Mining Co. of Lead, S. Dak. as a part of the Bureau of Mines program for investigating potential domestic sources of manganese. Half of the sample was taken from the 300-foot level and half from surface cuts. The problems involved were liberation and rejection of silica and iron and removal of lead, Silver, and gold from the manganese concentrates. Although a portion of the silica and iron oxides was too intimately associated with manganese minerals for rejection by ore-dressing methods, thus limiting recovery of high-grade concentrates, the Richmond Hill ore was found amenable to simple gravity methods of concentration for producing intermediate-grade products. By jigging and tabling, 73.8 percent of the total manganese was recovered in a product that, when sintered, assayed plus 40 percent Mn. Lead, silver, and gold were successfully removed from gravity concentrates by a chloridizing roasting treatment.

Jan 1, 1948

REJUVENATED is an apt word to apply to Chino, Kennecott's big open-pit mine at Santa Rita, New Mexico. Back in 1923 Chino was merged with Ray by an exchange of shares, and in 1926 the Ray-Chino combination was taken over by Nevada Consolidated through an issue of bonds that were traded for the Ray and Chino assets. Subsequently, of course, the whole package was acquired by the Kennecott Copper Corporation. On the basis of the terms of the Ray-Chino-Nevada exchanges, Chino was rated third in value, something less than thirty per cent of the total. In 1955 the appraisal would doubtless be forty per cent or more. But it is not only vis-a-vis Ray and Nevada that Chino has blossomed out. At the end of 1931, Chino ranked seventh among the Porphyries in point of output; whereas by the end of 1954 it was fifth,. having passed both Inspiration and Nevada Consolidated. Sharp curtailment in production in 1932-33-34 and total suspension in the two years following (see Fig. 21) found the property in a somewhat parlous position. However, the engineers had not been idle; they had been planning for the future, and in 1937 a far-reaching program of rejuvenation was launched. During the ensuing five years, capital expenditures totaled more than $8,500,000. Among the projects undertaken were the following: (1) Mine-Purchase of larger and better equipment for drilling, loading, and transporting the ore. (2) Mine-Beginning of the first systematic project to leach and recover copper in the waste dumps at the mine.

Jan 1, 1957

By S. K. Kawatra, T. C. Eisele

The separating efficiency of a flotation column is largely limited by the degree of back mixing of tailings into the froth zone, and the recovery is limited by the degree of short-circuiting of feed to the tailings. Current columns are typically constructed very tall (30 to 40 ft) to limit the effects of back mixing and short-circuiting. These effects can also be reduced in a much shorter column, provided that the flow in the column approaches plug flow. In this work, horizontal baffles were shown to improve the performance of a 6 -ft laboratory-scale flotation column treating a poorly floatable coal. Tests with variations in the baffle positions showed that baffles are needed both above and below the feed inlet to achieve the greatest benefit. Tracer tests with a fluorescent dye in water showed that baffles reduce the amount of feed water entrained in the froth at any given coal recovery.

Jan 1, 1996

By W. L. Fink, L. A. Willey

DURING the war there was introduced a new higher strength aircraft alloy designated 75S.1,2.3 The properties of this alloy assure extensive applications in both military and commercial aircraft. It is therefore important to understand its limitations as well as advantages. The properties of 75S alloy in the heat-treated tempers, like those of many other aluminum alloys, are affected by the rate of quenching. In general, low quenching rates tend to cause low strengths and to adversely affect the resistance to corrosion. Commercial quenching procedures are usually sufficiently rapid to permit the development of maximum properties. However, in the center of heavy sections, such as large rolled and extruded shapes, the quenching rates may not be rapid enough to develop maximum strength or resistance to corrosion. The investigations of 75S alloy described herein reveal the most critical range of temperature and the effects of quenching sheet and extrusions at different rates through that temperature range, on the tensile properties and resistance to corrosion. PROCEDURE Preparation of Specimens Sheet specimens (3 in. by 9 in.) were prepared from a commercial lot of 75S "as rolled" sheet (0.064 in. thick). The composition° was as follows: Weight Percentage Cu Mn Mg Zn Cr Al with Normal Impurities 1.64 0.16 2.58 5.66 0.27 Remainder The specimens employed for the determination of the time-temperature relations during quenching of sheet were prepared by the following procedure: the hot junction of a 28-ga. iron-constantan thermoelement (asbestos insulated) was brazed to a thin strip of aluminum which was in turn brazed into the end of a 3/16 in. i.d. by ¼ -in. o.d. by 30 in. long aluminum protection tube. Before brazing, the tube was flattened to 0.064 in. thickness over the junction and adjacent lead wires for a distance of 1 ½ in. The flattened end of the tube was fitted into a slot cut from one edge to the center of the 3 in. by 9 in. by 0.064 in. sheet and brazed into place. The brazed joint was dressed to the thickness of the sheet and the entire specimen buffed to approximately the brightness of "as rolled" material. Because of the brazing operations required, these specimens were prepared using 3S alloy. For the investigation of quenching rates in heavy sections, there were used 75S extrusions which had compositions similar to that of the sheet. The specimens consisted of 14 in. lengths of ¾ in., 2 in., 3 in. and 4 in. diam cylindrical rods and a roughly rectangular extruded section which was approximately 4 in. by 7 ½ in. Thermocouples were peened into the bottoms of 1/8 in. diam wells drilled into one end and parallel to the axis to a depth of

Jan 1, 1947

By Soseol Kim

A high-performance Emulsion-based booster explosives has been developed that can be used as a booster for bulk explosives. Currently, Pentolite booster, which is mainly used as a booster for bulk explosives, has a high risk of accidents due to the sensitivity of its raw materials PETN and TNT, and has a low melting point, making it impossible to use it in high-temperature ground. The Emulsion-based booster was developed to maximize the Velocity of Detonation (VOD) while elimination the shortcomings of the Pentolite booster. The VOD of the Emulsion-based booster is about 6,500m/s, so it can maximize the performance of the bulk explosive. In addition, it can be used in high-temperature ground and does not cause accidental detonation due to the external environment. In this article, the performance of the Emulsion booster was verifies through comparative test blasting of the developed Emulsion-based booster and Pentolite booster.

Feb 6, 2023

By Gerardo Muñoz

All along this century CODELCO's smelters have been operating on conventional technology, which Codelco has streamlined by using oxygen, developing oxy-fuel burners for reverberatory furnaces and introducing oxygen smelting of concentrates in converters (Teniente Converters). Chuquicamata began capturing sulfur from its first Teniente Converter in 1985. Since then, it has implemented a program allowing to gradually increase such capture. In 1994 a Frame Law on the Environment was enacted in Chile. By virtue thereof and of CODELCO's corporate environmental policy, an investment program aimed at capturing more than 95% of gaseous pollutants in all its smelters in a term not exceeding twelve years was established. The above entails a substantial improvement of the operational management as regards fugitive gases capture and treatment. This paper describes the way CODELCO is to deal with this challenge with a view to fully complying with environmental regulations and obtaining the required environmental certifications of its operations.

Jan 1, 1996

By James B. Meredith

The European Economic Community (The Common Market) is now shifting from I a coal oriented to an oil oriented economy. The proportion of energy supplied by oil has increased from only 13% in 1950 to 38% in 1962, and will approach 50% by 1970. In the past five years Common Market petroleum demand has in- creased 15% per year compared with only 3% per year in the United States. This rapid shift to oil can be explained by looking at oil's competition, First; there is simply not enough other energy - European coal, natural gas and hydro-electric power - to meet the demand, Secondly, oil?s primary competing energy in the Common Market is coal, and Community coal is high-priced - it costs more than two and a half times as much as U. S, coal at the pithead. The third reason for the shift to oil is consumer preference for the ease of handling, convenience and cleanliness of liquid fuels. As these reasons suggest, much of the shift to oil and the resulting growth in demand would have occurred whether or not the Common Market organization had existed. On the other hand, the Common Market has stimulated the use of oil by causing a higher rate of energy consumption, and oil has been the beneficiary of most of this growth.

Jan 1, 1963

By John Mark Patek

Knowledge of the relative floatability of silicate minerals is increasing in importance as flotation is being applied to the concentration of nonsulfides. Many silicates are in themselves commercial products amenable to concentration by flotation. Moreover, the selective flotation of other nonsulfide minerals, such as cassiterite, depends largely upon the floatability of associated gangue silicates. Differences in floatability existing between the various silicates have not- been sufficiently appreciated; for example, the feldspars that differ greatly in floatability have generally been merely treated as "feldspar." It was the purpose of the work described in this paper to determine by experiment the differences in floatability between silicates; to investigate the causes for such differences, and to discover a means of predetermining approximate floatability without the necessity of experimentation. Determining Floatability The relative floatability of 20 silicates so selected as to represent all of the more common silicate types1 was obtained by flotation tests enumerated in Table 1. The mineral to be floated was crushed dry on a steel plate, and screened repeatedly during crushing through an 80-mesh screen in order to produce a sand with all grains as close to 80 mesh as possible. The sand was placed in dilute (6N) hydrochloric acid until free of soluble foreign material, and then washed with tap water about ten times in order to remove both acid and fines. The resultant product, which averaged 82 per cent plus 200 mesh, was floated in 50-gram charges in a 50-gram Denver celluloid flotation machine with 0.008 gram of terpineol, and from 0.01 to 0.05 gram of oleic acid in a solution acidified with sulfuric acid. The degree of separation of one mineral from another was determined by counting under a nlicroscope the grains of each mineral, both in the concentrate and in the tailings, and comparing their relative abundance in each. Unless the comparison showed a decided difference in amount,

Jan 1, 1935

By Earle E. Schumacher, W. C. Ellis

For the purpose of developing combinations of higher strength and conductivity than are obtainable by heat treatment alone in the age-hardening copper alloys, an investigation has been made of the effects of combinations of heat treatment and strain hardening on the properties in question. The investigation was limited to a study of the alloys containing nickel and silicon; nickel, silicon and cadmium; and cobalt and silicon. The experiments made in the course of the study arc described in this paper in three groups: 1. The effect of hard drawing subsequent to heat trcatment on the mechanical and electrical properties of the alloys. 2. The effect of low-temperature aging on the properties of heat-treat,ed and hard-drawn alloys. 3. The effect of strain on the rate of aging of quenched nickel-silicon-copper alloys. Preparation and Compositions or the Alloys The alloys were prepared by melting cathode copper in an electric resistance furnace and adding sufficient of the hardening elements to bring the compositions to the desired values. The purities of the hardening elements were as high as could be obtained in commercial practice. The metals were what are designated in the trade as electrolytic nickel, cobalt rondelles, commercial stick cadmium and fused silicon. The alloys

Jan 1, 1931