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By Raymond K. Will

Computers are becoming increasingly valuable tools in the mining industry as a greater variety of appropriate hardware and software becomes available, combined with greater acceptance by management, Within a given time period an engineering staff can evaluate or design a project to much greater detail and higher accuracy by utilizing computers once suitable programs have been developed. We are all aware that throughout the world the decreasing grade of minerals coupled with increasing waste to ore ratios necessitate larger capacity, longer term mining operations and attendant higher capital costs. Computers can be of assistance in all stages of mineral exploitation, from geologic exploration through mine feasibility studies and design, to marketing and transportation. Because of the high speed with which data can be digested and manipulated by computers, preliminary information from any stage of investigation can be analyzed to assist in further guidance of that stage. By use of preliminary mine feasibility studies, financial forecasts and sensitivity analysis, even information from a far-removed phase such as marine transportation of the product, can help guide the exploration phase to a realistic target.

Jan 1, 1973

By D. H. Lynch

Prompted by the need to conserve energy and reduce operating costs, Agrico Mining Company has made two significant improvements in the transportation of phosphate ore from the mine to the beneficiation plant. One improvement involves a change in a slurry pipeline system which substantially reduced pumping energy, and the other improvement is a major innovation for the phosphate mining industry which involves the transportation of the ore by railroad. This paper briefly describes these two projects.

Jan 1, 1981

By Ernest Hucke

This paper will cover basic pneumatic and electronic sensors, transducers, transmitters and their application in the Mining Industry.

Jan 1, 1965

By R. Perez

The consumption of grinding media forms a significant part of the operating cost of a mineral processing plant. An estimated half billion pounds of steel in the USA and over one billion pounds in the world are consumed each year in wet grinding alone. However, there is some conjecture as to the interacting roles of abrasion and corrosion. In order to provide a more complete picture of the conjoint action of abrasion and corrosion, marked ball tests were conducted on different grinding ball compositions in a laboratory ball mill and the metal losses were measured on varying the conditions, i.e., pH, PO2, in wet grinding a Cu-Ni gabbroic rock and compared with taconite grinding. Ball wear rates ere discussed with respect to ball composition and microstructure and the varying conditions used in the grinding tests.

Jan 1, 1984

By M. Manrique

Various pyrometallurgical methods for treating Ilmenite and Zircon concentrates are reviewed. Laboratory experiments, using a thermal plasma reactor, have been performed to evaluate: the conversion of ilmenite to TiC or TiC-Fe and the conversion of zircon to ZrC or ZrC-SiC. Results are examined and possible processing routes are identified.

Jan 1, 1996

By C. E. Silverblatt

The advent of larger quantities of -1/4 inch coal in the raw feed to the preparation plant and the necessity of recovering this material has made the problem of meeting product moisture specifications more difficult. For a number of years thermal dryers have been used advantageously as a means of reducing fine coal moisture content where the over-all economics would justify such an installation. However, these units are not without their drawbacks because of high capital and operating costs, safety hazards and possible degradation of the product, and thus an alternative method of moisture reduction is highly desirable. After the various mechanical variables associated with filtration have been optimized, an examination of theory shows that surface tension and liquid viscosity are the only two remaining variables which might be altered to reduce moisture content.

Jan 1, 1964

By S. E. Phillipson

Four massive pillar collapses in limestone mines, and one in a marble mine, occurred between 2011 and 2021 in benched areas at the Appalachian physiographic province. We characterized the rock mass at 43 limestone mines using the Geological Strength Index and, by plotting the results on a physiographic relief map, determined that GSI values between 55 and 70 preferentially occur in the Appalachian and Ouachita Mountains, which were subject to deformation during the Ouachita and Alleghanian Orogenies. Limestone mines located in formations of similar age in the Interior Plains, where deformation was less developed, are characterized by Geological Strength Index values over 80. We present the results of pillar strength calculations that incorporate the Geological Strength Index from mines that experienced massive collapse, as well as from mines with benched areas that did not collapse, to demonstrate the negative effect that a jointed rock mass has on pillar stability. We suggest that pillar designs, particularly those in which benching will be incorporated, should include allowance for rock mass quality. Because of the preferential dominance of lower GSI values in the Appalachians, we further suggest that pillar designs in this environment may require additional engineering assessment, especially where benching is intended. Lower GSI values may often translate into greater overbreak, which results in loss of pillar volume, corresponding wider back spans, and a decreased width-to-height ratio.

Jun 25, 2024

By Paul A. Rittenhouse

Its a pleasure to be with you this afternoon and to talk briefly on one of my favorite subjects -- the U.S. sulphur industry. As our Chairman mentioned, I have been associated with the sulphur industry either directly or indirectly for the last twenty years, both on the production side and as a consumer. Sulphur, while unseen and relatively unknown to most people, is like margarine ... that ubiquitous spread ... that is yellow and nearly omnipresent in the industrial world. It is because sulphur, in some form, is required in nearly all aspects of our economy that makes its study so interesting to me as a researcher. An analysis of the sulphur outlook requires examination of such industries as fertilizer, paints and pigments, copper and zinc, uranium, petroleum, chemicals, pulp and paper and textiles - just to name a few. Of course, because its use is so widespread and ever-changing it is difficult to develop and maintain a good understanding of the sulphur industry. It is also a problem to cover the industry in a short discussion and to project its really dynamic nature. Hut, if you will bear with me, I will attempt the task. First of all, let me say that sulphur today is a world commodity and to a large extent moves freely in world trade; nearly a third of the world's sulphur or something over 15 million tons in 1974 entered international trade. However, today our interest is in the current changing sulphur picture in the U.S., with particular emphasis on the western part of the country.

Jan 1, 1975

By D. A. Poulter

The stability of a liner system is influenced by many factors which can be compiled into four basic groups. They are: 1. the liner system components and physical characteristics; 2. the geometry and slope of the liner system; 3. the loading conditions on the liner system; and 4. the foundation conditions under the liner system. Failures in the liner system that are due to one or more factors from the first three groups usually result in movement relative to the plans of the liner system. Failures associated with factors in the fourth group result in deformation(s) across the liner system section beyond its design limits. For purposes of these discussions a failure in the liner system refers to displacements or movements resulting in physical damage to the liner system such that it can no longer function.

Jan 1, 1995

By L. H. McGuire

Many coal beds in the State of Washington, pitching as much as 90°, offer unusual mining conditions. This paper describes methods and safe practices of mechanized mining in pitching bituminous-coal beds that have attracted the attention of mining people from most of the coal-producing countries of the world. The development and use of continuous miners as part of the mechanized program apply particularly to the Roslyn-Cle Elum coalfield, Kittitas County, Wash. All three mines now operating in the field use continuous miners and during 1957 furnished 72 percent of the State's total coal production. Mining operations are now conducted in three coal beds of the Roslyn-Cle Elum field. The coal measures range from 3-1/2 to 20 feet in thickness and vary in dip from 5° to 45° in the localities where the coal is mined. Some safety measures adopted by-the principal operating company in the field during the past 30 years of mechanized mining follow: Use of only permissible electrical or compressed-air-operated equipment on other than intake air; providing and using an explosion gallery to test repaired permissible electrical equipment before taking it underground; use of only compressed-air-operated drill augers in preference to permissible

Jan 1, 1959

By Frank J. Klima

Explosives are probably the most widely used and most mysterious large scale' mining tools of modern times. The post black powder explosives were primarily nitroglycerin-based straight dynamites, ammonia dynamites, blasting gelatin, gelatin dynamites, ammonia gelatin dynamites, etc. Of these, the strongest and highest velocity explosive used in industrial operations is blasting gelatin, which is nitroglycerin colloided with a nitrocellulose of medium nitrogen content in proportions which give the product a plastic character, or about 93 to 7. Many variations of the basic groups above were developed by substituting ammonium nitrate and/or sodium nitrate for some of the nitroglycerin. The nitrates being insensitive to caps required a certain percentage of nitroglycerin to sustain detonation in smaller quantities or diameters. Paralleling the development of industrial dynamites was the development of more expensive, highly sophisticated explosives which were developed for specific military purposes. Such explosives as Amatol, RDX, Composition A, Composition B, Composition C, Lead Azide, PETN (Pentaerythritol Tetranitrate), Tetryl, Pentolite, TNT, etc., were primarily military explosives. Amatol, which is a cast mixture of ammonium nitrate and TNT (Trinitrotoluene), and identified by percentage of AN versus TNT as 50-50 Amatol, 80-20 Amatol, etc., was a favorite World War I explosive. RDX, or Cyclonite, was widely used in World War II. Also used during WW II were compositions A. B, and C, which were mixtures of RDX (Cyclotrimethylene trinitramine), TNT, and other nitrotoluenes. These high explosives, along with nitroglycerine, are exact chemical compositions or mixtures of exact chemical compositions which are individually explosive, or in other words, individually capable of explosive chemical decomposition when properly initiated. These chemical decompositions result in the formation of simpler compounds and/or large quantities of common combustion gases, and large amounts of energy in the form of heat. Of these, the most powerful is RDX which, based on the ballistic mortor test, is 1.5 times as powerful as TNT. Chemically, the decomposition of TNT releases about as much energy as the reaction of ammonium nitrate and fuel oil.

Jan 1, 1967

By B. G. Kelley

The MIDREX® Direct Reduction Process was developed during the 1960s by the Midland-Ross Corporation, which had pioneered shaft furnace technology and stoichiometric gas reforming for use in processing minerals. In 1969, the first MIDREX® Direct Reduction Plant was built in Portland, OR. Since then, 49 additional modules have been sold in 18 countries. For the last ten years, over 60 percent of the world's direct reduced iron has been produced in MIDREX Plants. During the quarter century since commercialization, many technical improvements have been made, including larger shaft furnaces, in-situ reforming, greater heat recovery, improved catalysts, and hot briquetting. Midrex continues to enhance the technology in the areas of economy-of-scale, energy efficiency, alternate fuels, and raw material flexibility.

Jan 1, 1998

By Edward P. Larsen

At our annual meeting in St, Louis, Mo. in February 1961, we presented a comprehensive paper (No. 61-B-22) on the subject of "Blending and Handling of Materials for Agglomeration". In that paper you will find a discussion on the difference between "blending" and "mixing". With regard to "blending" we brought out the facts of its usefulness for the preparation o materials in an agglomerated mass to attain controlled chemical and physical uniformity. "Mixing" was discredited as not being useful for the attainment of uniformity of any kind.

Jan 1, 1962

By G. Richard Dreese

Most coal mining states have passed or amended laws restricting strip ruining in the past two years. In light of this and in anticipation of further restrictions by the states and the federal government on strip mining this paper attempts to show the Impact of these new laws on the structure of the coal mining industry in Ohio and specifically on one small stripping firm in Ohio. The implications of the study are applicable to other states under similar circumstances and to other industries which are being caught up in the ecological-economic struggle.

Jan 1, 1973

By Fumio Wada

Kuroko deposit is a stratabound massive sulphide and sulphate deposit associated with Miocene submarine volcanics and has been considered to be a prototype of meta- morphosed Palaeozoic and Precambrian equivalents. Since the discovery of Uchinotai deposit of the Kosaka mine in 1959, Dowa and other mining companies have conducted intensive exploration work in the Hokuroku district of northeastern Japan. Dowa has been placing its first priority on the exploration of Kuroko deposits and made a series of remarkable successes in finding the Kuroko deposits, i.e. Uchinotai, 1959; Matsumine, 1963; Uwamiki, 1966; Fukazawa, 1969 and Ezuri, 1975. It is emphasized that our successes have resulted from the proper application of exploration technologies accumulated through our experiences. Firstly we defined the Kuroko horizon and favourable felsic volcanism based on the detailed structural and volczno-stratigraphic study of the Hokuroku district, and then delineated the promising areas by means of the quantitative evaluation of geophysical, geochemical and mineralogical parameters such as the magnetic susceptibility and contents of alkaline and alkaline earth metals in the foot wall dacites and clay mineral assemblages of both hanging and foot wall pyroclastics and dacites. Practical application of these techniques is essential to our routine Kuroko exploration.

Jan 1, 1982

Water contact angles in the air/water/francolite, fuel oil/water/francolite and fuel oil/water/quartz systems were measured to describe the wetting characteristics of these minerals. It was found that white francolite is more hydrophilic than black and tan francolite both in the absence and presence of fatty acid addition. The contact angle measurement results do not correlate very well with the flotation response and it appears that kinetic aspects of the bubble attachment process play an important role in the francolite-fatty acid flotation system.

Jan 1, 1997

By Jr. Raleigh

Three run-of-mine bituminous coals, which ranged in rank from low volatile to high volatile A, were floated at nominal -28 mesh (590 µ m), -100 mesh (150 µ m), and -400 mesh (37 µ m) feed particle sizes with selected pyrite depressants and a dispersant. For the coals tested, pyrite and ash-forming minerals were usually rejected best at a -100 mesh feed particle size. Depressant additions tended to improve flotation selectivity between pyrite and coal. When joint dispersant-depressant systems were used at -100 mesh (150 µ m) feed particle sizes, the total sulfur content of the clean coal decreased further. For a comparable coal yield, less fuel oil collector was required for the flotation of -100 mesh coal than was required for the flotation of either -28 or -400 mesh feed.

Jan 1, 1990

By R. L. Clayton

The Bagdad district is 67 kilometers west of Prescott, Arizona, (Figure 1). The area north of the Old Dick and Bruce Mines was originally mapped by Anderson, Scholz and Strobell between 1943 and 1945, (1). The region is perhaps better known for the Bagdad porphyry copper deposit of tertiary age. However, 2 to 5 kilometers south of this deposit are several small massive sulfide occurrences in a eugeosynclinal Precambrian greenschist environment. More specifically, in. the Bridle formation of the Yavapai schist series. Three of these mines - Old Dick, Bruce and Copper Queen - were mined by Cyprus Mines Corporation between 1957 and 1977, and produced nearly 2mm tons of 3.6% copper and 12% zinc. These deposits occur at the interface between andesite and rhyolite and are stratiform in character. Certain structural and textural properties of the Bruce orebody suggest that remobilization of the massive sulfides occurred at some period during the metamorphic history of the area.

Jan 1, 1978

By Per-Martin Sandgren

LKAB's ores have specific mineralogical properties that make them especially suitable for the production of super-grade concentrates. Conditions are particularly good for this purpose at Malmberget, where a concentrate for high-purity sponge iron production has been produced for many years. Until 1978 the approximate assay was 71.2 % Fe and 0.45 % SiO2. Since then the assays have been improved by process modifications to approximately 71.5 % Fe and 0.20 % SiO2. Scope exists for still further improvement. In recent years the production of fractioned concentrates has been started. The material lies within the size range 74-125 µm and the approximate chemical analysis is 71.6 % Fe and 0.30 % SiO2. Other special products are under discussion. The Malmberget ores are also suitable for the production of high-purity direct reduction pellets with a SiO2 content below 1 %.

Jan 1, 1981

By L. G. Austin

A simple finite difference algorithm has been used to compute a simulation model for unsteady-state ball milling. The model considers the mill to act as if it were three fully-mixed reactors in series (one-large/two- small), it incorporates the-Rogers-Austin mass transfer law relating mill hold-up to flow rate through the mill, and it allows for the reduction in breakage rates caused by over-filling of the mill at high flow rates. The computation is rapid and requires only small storage space. Examples are given of use of the model.

Jan 1, 1984