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By E. W. Bauman

The important role that mineral aggregates assume today in the construction and chemical industries is best attested to by the astronomical tonnage figures for the annual production of aggregates in the United States as reported by the U. S. Bureau of Mines in their "Minerals Yearbook." For 1965, latest publication available, the tabulation shows a total of 1,716,000,000 tons made up of 30,000,000 slag, 908,000,000 sand and gravel, and 778,000,000 crushed stone. A much more favorable statistical position for slag can be established by listing the world-wide tonnage. According to Dr. A, W. Lee, Director, British Slag Federation, in a paper presented before the 8th Annual conference of the British Institute of Works and Highway Superintendents, he estimates that the probable world consumption of slag is in the order of 100,000,000 tons showing--Great Britain with 10,000,000 tons, Germany, 15,000,000 tons, France, 1$000,000 tons and the United States with 30,000,000 tons. Thus it is seen that the United States accounts for almost one-third of the world's consumption of slag and the 3 west European powers another third.

Jan 1, 1967

By Giovanni Barla

This paper examines the application of gelatin mixture models to the study of factors such as gravity effects, tectonic and residual stresses, anisotropy, physical nonlinearity, time-dependent behavior of the rock mass and connectedness of the geologic space. The calibration technique of gelatin mixtures, proposed by Richards and Mark in 1966, is applied to the particular problem considered. Similitude relationships between model and prototype are discussed with reference to the constitutive equations describing the physical behavior of the rock mass. The interaction between two openings in a linearly elastic medium, under conditions of plane strain, is used as an illustrative example, with the view of describing the history of stress and deformation changes on the rock medium and lining around a slusher drift while undercuts are made in block caving.

Jan 1, 1968

By Ray E. Harris

A resource of 134,400,000,000 tons of minable trona and mixed trona and halite underlies an area of about 1,300 square miles vest of Green River, Wyoming (Culbertson, in preparation)(Figure 1). In 1982, the total domestic consumption of soda ash (refined trona) was 6,667,000 short tons (Kostick, 1983), approximately 90 percent of which came from Wyoming trona. This enormous resource occurs in the Wilkins Peak Member of the Creen River Formation (Eocene). The Green River Formation is derived from sediments deposited in a large lake (Lake Gosiute) that occupied the Green River Basin in south-western Wyoming 38-54 million years ago. The Wilkins Peak Member represents a restricted, evaporite-rich cycle of deposition during which time the trona deposits were formed. A total of 42 trona beds are known, of which 25 are of sufficient thickness and extent to be considered minable (Culbertson, in preparation).

Jan 1, 1984

By T. M. Klemetti, T. J. Batchler, T. J. Matthews

"From 2011–2016 there were 1,511 documented injures, including 7 fatalities, from ground falls in U.S. underground coal mines. The majority of these ground fall injuries were not caused by a major roof collapse, but from falls of smaller rocks from the immediate roof. Roof screen can significantly reduce the number of these injuries and has been widely utilized in underground coal mines for surface control. Because of the potential of reducing ground-fall injuries, the National Institute for Occupational Safety and Health (NIOSH) is further evaluating the performance characteristics of welded wire screen as used in underground coal mines by conducting a laboratory testing program at the Mine Roof Simulator (MRS) in Pittsburgh, PA. The load-displacement characteristics of a 2.4-m x 3.7-m panel of 8-gauge welded screen were evaluated using a newly designed, large laboratory screen test frame with multiple load pull locations. This screen was tested in a configuration that simulates current installation practices in U.S. coal mines. In this study, the effects of displacement loading rate, load pull surface geometry, and the inclusion of roof channel on the screen performance were evaluated. Ultimately, the type of information obtained in this and similar studies can be used to aid in developing wire roof screen design criteria and to assist mine operators in the selection and use of roof screen in underground mines. INTRODUCTION Over 1,500 injures, including 7 fatalities, occurred from 2011–2016 from ground falls in U.S. underground mines with the majority of these ground-fall injuries caused by falls of smaller rocks from the immediate roof. Various controls are currently being used in mines to control this surface rock, including the use of wire roof screen. In mines where wire roof screen has been installed, injuries from rock falls have been reduced dramatically (Robertson and Hinshaw, 2001). Roof screen has the potential to prevent hundreds of injuries caused by the fall of small rocks between permanent roof supports (Comptonet al., 2007). Because of this potential for reducing ground-fall injuries, the National Institute for Occupational Safety and Health (NIOSH) is evaluating the performance characteristics of welded wire screen as used in underground coal mines by conducting a laboratory testing program at the Pittsburgh Research Laboratory (PRL)."

Jan 1, 2018

By Kazumasa Taguchi

At the Kakogawa works of Kobe Steel. Ltd., the agglomeration facilities are composed of a pelletizing plant and sintering plant. This aim is to utilize raw materials efficiently and stabilize the raw material resources. Therefore at Kakogawa works, the blast furnaces (BF) have been operated with high pellet ratio and various developments for pellet properties have been achieved to improve the blast furnace performance. These developments include dolomite-fluxed pellets, new-porous pellets and crushed pellets. As a results of these improvements, pellets have achieved almost the same performance as sinter at high temperature regarding properties such as the softening, melting and reduction behaviour. However, some problems on shape have remained to be solved. Spherical pellets flow easily into the center of the furnace and form mixed layers of pellets and cokes. Therefore, in BF operations with these pellets it becomes more difficult to keep proper and stable gas distribution.

Jan 1, 1983

By Arne Paus-Jenssen

The potash industry in Saskatchewan has recently been the focus of much new legislation at the provincial level and, along with other mining industries in Canada, also subject to changes in tax legislation at the federal level. As a result, the industry presently operates under (a) provincial production controls, a prorationing scheme; (b) a new provincial reserve tax on potash only and; (c) a new federal income tax applicable to all mineral industries. The prorating scheme dates back to 1970 and emerged as public policy because of the excess supply situation faced by the international potash industry towards the end of the sixties. This caused special problems for new mines in Saskatchewan and the provincial government decided to intervene. The new tax legislation at provincial and federal levels, both introduced within the last four years, reflects a belief that insufficient revenues accrue to the public sector from natural resources. All mining industries in Canada, including the potash industry, have had their tax positions completely reversed during these four years. Traditionally the mining sector in Canada has been a recipient of substantial tax incentives and has enjoyed low tax rates. This has changed and the mining sector is now one of the most heavily taxed sectors in the economy. In addition, the mining sector has moved from a situation where its rapid development was favoured by governments to a situation where this is no longer the case.

Jan 1, 1976

By S. K. Kawatra

In this paper three methods of on-stream analysis 1) Radiometric techniques, 2) X-ray tube techniques and 3) Neutron activation method are reviewed. Advantages and disadvantages of each method are discussed.

Jan 1, 1984

By L. J. Lindsay

Kaiser Resources Ltd. operates a coal mining complex in Southeastern British Columbia. A large surface mine, a conventional underground mine, and an innovative hydraulic underground mine are presently in operation. The products of these mines are fed to the Elkview plant. This coal has to be prepared to 9. 5% ash and 6'o total moisture for export from the port of Roberts Bank near Vancouver, British Columbia to Japan at a rate of 4. 5 Mltpy. The moisture requirement for the coal product was recently increased to 8. 0% total moisture. The entire operation has been described in various publications (1), (2), (3). Details of the venture will not be repeated in this paper. In this paper we hope to describe the modifications made to the original coal preparation plant in order to satisfy market requirements for quality and quantity of coal.

Jan 1, 1974

By J. S. Hall

The productivity and fuel efficiency of iron-ore blast furnace operations has greatly increased in recent times. These improvements, particularly to the Japanese steel industry, have primarily arisen from process engineering studies of the blast furnace and associated operations such as sintering. The development of fluxed sinter based on iron-ore fines reacted to produce highly reducible, low slag sinters has contributed further to a reduction in fuel requirements. The Pilbara province of Western Australia is a significant source of these iron-ore fines supplied to the international market. Increasingly, this market is being offered high quality ores from other foreign sources. To technically assist companies in improving the processing efficiency of ores, and to improve the technical marketing of ores by modelling the processing characteristics of Australian/international ore blends, the Commonwealth Scientific and Industrial Research Organization (CSIRO) is actively assisting the industry by researching the general theme of 'iron ore from mine to metal in this paper we outline progress towards a numerical description of: a. ore deposit classification. b. Degradation during transport. c. Direct reduction of iron ore. d. Liquid bath ore reduction/smelting. e. Industrial sintering.

Jan 1, 1986

By Myron W. Mellor

Our efforts at McNally, to find a better way to mechanically separate particles from liquid in a slurry have led to the development of two new centrifuges. The first unit utilizes a slotted opening screen as the filter media and retains all plus 200 Mesh and most of the 200 by 300 Mesh particles. The second unit is a solid bowl centrifuge with a novel method of removing the solids and delivers an effluent containing as little as 300 PPM solids in suspension. The first unit was designed to separate particles in the range of about 1 MM x 0 or smaller top size from the liquid slurry and produce solids having low surface moisture content, and a liquid concentrate containing a low percentage of solids. A prototype of this unit has been in the field undergoing tests for over two years. A few of these test results are shown in Tables I & 11. Testing has been mostly limited to the field of coal, how- ever this does not mean that the machine would accept only coal slurries. The machine has produced a dewatered product having as low as 5.5% surface moisture, and an effluent containing as low as 1.4% solids and handled slurries containing from 15 to 50% solids by weight.

Jan 1, 1975

By Rodger C. Smith

The topic chat has been assigned to me ?Economic and Political Climate of the Potash Industry? is a function of two basic facts: 1. Potassium is absolutely essential to plant and animal growth. Along with nitrogen and phosphorus it is one of three major plant nutrients, the three nutrients required in largest quantities for plant growth. 2. United States is unequivocally an "have not" nation with regard to potassium. Quantity of potassium ores is limited and, more disturbing, the cost of production at all U.S. potash mines is marginal in comparison with the major producing countries, i.e. Canada and U.S.S.R.

Jan 1, 1983

By Wilfred M. Kenan

The relationship of various genetic classifications of graphite, their properties and general applications are reviewed. The classifications being amorphous, flake, high crystalline (vein) primary synthetic graphite and secondary graphite. The properties discussed are size, carbon, sulfur, ash content, general chemical analysis and degree of graphitization of each type. The major sources for natural and synthetic graphite powders are discussed in addition to factors which govern the cost as well as the supply. The economics of graphite are basically determined by the consumer and the end application. Graphite is a strategic mineral and is on the government stockpile list.

Jan 1, 1984

By Reed S. C. Rogers

The breakage parameters of phosphate ore were determined by batch first-order grinding studies in a laboratory ball mill according to the procedures described in the text by Austin, Klimpel and Luckie, using a slurry density of 70 weight percent. The results were scaled to five larger mills of 0.56 m diameter by 0.91 m length (2 ft. by 3 ft.), 0.82 m by 1.52 m (3 ft. by 5 ft.), 3.36 m by 7.90 m (11.5 ft. by 25 ft.), 4.41 m by 9.10 m (14.5 ft. by 30 ft.), and 5 m by 11.1 m (17 ft. by 36 ft.), assuming equilibrium ball charges for the full-scale mills. The results were used to predict product size distribustions and capacities for batch grinding in the 0.56 m and 0.82 m diameter mills and open circuit grinding in the 0.82 m diameter and larger mills using a one-large/two-small reactors in series model fitted to the residence time distribution measured in the 4.41 m diameter mill. The simulated results were compared to plant data for ranges of mill capacities. It was found that the simulated product size distributions were in good agreement with the experimental values below the 70% passing sizes, but did not agree so well in the top sizes. The predicted capacities were in approximate agreement with experimental values for the pilot-scale mills, were about 7 percent too high for the 3.36 m and 4.41 m diameter mills and about 25 percent high for the 5 m diameter mill. Use of the Bond method with the measured Work Index of the phosphate ore gave capacity predictions that were 45 to 150 percent too high.

Jan 1, 1985

By Terrence J. Stobbe

On the job injuries to the musculoskeletal system are probably the oldest of the industrial safety problems. Long before we had pinchpoints to guard, chemical vapors to ventilate, and noise to enclose, people were getting strains, sprains, and sore backs from their work activities. In spite of the age of the problem, it remains a long way from being solved. The past ten years have seen a significant commitment by the sci¬entific community to understanding the problem. Engineers, scientists, doctors, and epidemi¬ologists have been involved, and as a result, today we have a much better understanding of the problem. The first step in understanding a problem such as this is to explore its history and epidemiology. The research done by Chaffin (1977), Snook (1970), Ayoub (1978), the ILO (1962), and others, led NIOSH to publish its Work Practices Guide for Manual Lifting in 1981. The guide was based on research carried out in general industry, but subsequent research by Stobbe (1983) and Peters (1983) has suggested that the nature of the problems producing injuries in underground mining is the same as in general industry. The problems are more intense in the mining environment.

Jan 1, 1984

By William L. Young

I think I should let you in on one of Canada's best-kept secrets, if you will promise not to tell it all over the place. Believe it or not, good, honest, enterprising capitalism is still alive and flourishing north of our common border, and I am living proof that capitalism is still working for the little guy. My personal story of mining development in Canada isn't all that rare -- you've probably heard something like it from other areas and other days several times -- but my case brings it up-to-date. I would like to Tell you briefly the history of Northumberland Mines Limited, a contemporary case of individual enterprise getting a mining operation underway. And if I can do it you probably can too.

Jan 1, 1981

By R. L. Wiegel

A well-defined geometric model for a mineral system and its liberation by size reduction is used to show the relationship between true volumetric particle composition and the composition estimates obtained by the measurement of linear intercepts or areas of simulated polished sections of particles. Based on this information, a transformation is developed between the areal measurements and the volumetric composition for this idealized mineral system. Key words: Gaudin random liberation model, Mineral liberation, Particle composition measurement

Jan 1, 2010

A significant technological development is discussed for the processing of certain problem power plant flyashes which contain a high water soluble mineral content and which are known to yield inferior flyash based brick. This development is based on the addition of hydrochloric acid to the flyash-bottom ash-sodium silicate blends used for the production of flyash based structures. Favorable changes are evident in (1) sodium silicate consumption, where often approximately one-half of the amount used for making brick from normal flyash is required; (2) processing costs; and (3) strength and appearance of the resulting freshly formed green and fired structural products. In some high cost instances-(above the cost of 30 dollars or less per thousand brick estimated for normal flyashes) hydrochloric acid additions can replace or reduce other costly additives required with problem flyashes to result in a savings of as much as nine dollars per thousand brick. These developments offer promising possibilities for utilizing problem flyashes as well as flyashes which may come into contact with water soluble, sulfur as a result of the eventual application of certain experimental air pollution control processes.

Jan 1, 1968

By A. Kepeski

Cement industry relies heavily on the control of large volume of raw materials in the proximity of plant operations for clinker and cement manufacturing. These mineral resources are perhaps considered as ?low-profile? (mostly comprise limestone's, clays, marls and sands), but their availability, accessibility and suitability ? the later with respect to chemistry, mineralogical and physical characters ? are factors of paramount importance and may largely affect production cost and plant productivity. The combination of scarcity of good quality raw materials deposits and the growing environmental concerns have challenged the cement producers towards sustainability and the responsible exploitation of natural resources. In open pit mining and quarrying, the evaluation of mineral resources vs. handling of the non-usable overburden and other off-spec materials directly affects the medium to long-term production planning, quality control practices and environmental management. It is a general trend for many cement producers and a usual case for a number of Titan Cement plants worldwide, that redesign of quarry pits is necessary not only for stability purposes but also as a result of environmental constraints and emerging issues. The material reserves then have to be re-evaluated in the light of the new final pit design, safety distances from houses, other infrastructure and Law restrictions and according to criteria of safety of operations, reduction of environmental impacts, pit optimisation and proper future reclamation. The paper discusses the case of three active quarries of Usje Cement Plant, in Skopje (Macedonia), namely Usje (marl), Goverlevo (lime-stone) and Ljubosh (sand), where a large campaign of redesign and evaluation of recoverable reserves and the needs in rehabilitation took place in 2004. Technical and environmental issues and criteria are presented in the form of master plans and the highlights of the first attempts to propose and apply a reclamation scheme are discussed, by also examining alternative solutions for each quarry area. Finally, the 2005 progress in applying changes to the design of benches and pit layout, as well as experiences gained, are discussed.

Jan 1, 2005

By B. Waquet

The genesis of a hydrothermal subsea mound, by chimney debris heaping and mineralizing fluid circulating upward, induces a vertical maturation gradient. Connected porosity is easy to measure and, after mineralogical evidence, can be use as a maturation index. Thus, to understand how a rock property evaluates with maturation, it is possible to plot it against connected porosity. Results are that uniaxial compressive strength, Young's modulus, and in a lesser certitude tensile strength, abrasivity and hardness, increase very weakly with maturation until a maturation threshold (equivalent to a connected porosity equal to 0.2), and rocket to much higher values after it.

Jan 1, 2011

By William P. Shell

An important part of process control engineering is the implementation of the basic control system design through commissioning to routine operation. This is a period when basic concepts can be reviewed and improvements either implemented or recorded for application in future systems. The experience of commissioning the process control systems in the Homer City coal cleaning plant are described and discussed. The current level of operating control performance in individual sections and the overall system are also reported and discussed.

Jan 1, 1983