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By M. Vandewalle

What separates the support of mining openings from the support of similar civil engineering structures is the fact that mine openings have to survive large deformations as a result of changing stress conditions induced by progressive mining. Steel fibres impart to concrete and shotcrete a high degree of ductility which not only allows the shotcrete and concrete linings to absorb important rock movements but also to increase its bearing capacity by a redistribution of the loads. A range of applications will be discussed technically and economically.

Jan 1, 1998

By P. J. van der Walt

Some 30 years ago exposure to dense-medium separation in South Africa, culminated in the adaptation of the process for the treatment of -0.5 mm fines. The first commercial plant at Greenside Colliery apparently operated for some 18 years. Three further plants followed, including one treating tin ore. It is gratifying to learn, therefore, that there is renewed interest. The objective of making the process easier to operate (?more practical??) is commendable but the cumbersome technical approach could be counter productive. Perhaps a brief outline of the original thinking might be helpful when analysing the problem.

Jan 1, 2003

This paper has peen translated from the Russian by the United States Bureau of Mines and is issued as one of a series of circulars dealing with mining methods and costs in connection with a general study of this subject sponsored by the bureau. The paper presents some interesting features in connection with the methods employed in Russia and describes certain variations in standard methods which might conceivably be applied to a limited extent in this country.

Jan 1, 1930

By A. Burger Pintér

To be meaningful the sharing of ideas about the National Environmental Management Act (NEMA) and social issues within the context of Mining and Metallurgy (M&M) requires an honest scrutiny of the M&M/social environment relationship, both past and present. It is not a secret that this relationship has been and is fraught with difficulties. Thus from all perspectives (M&M, society and environmental and social consultants) such a dissection, that highlights the realities, both good and bad, is uncomfortable. For this section of the colloquium to have any value, the honest but difficult approach needs to be taken.

Jan 1, 2000

Council for 1999/2000 President M.H. Rogers President Elect Dr L.A. Cramer Vice Presidents Senior A.A.B. Douglas Junior S.J. Ramokgopa Immediate Past President J.R. Dixon Honorary Treasurer J.A. Cruise [ ] Annual report In accordance with the current management policy, this report on the activities of the Institute is presented under eight main headings: 1. Interests of Individual Members 2. Technical Meetings 3. Publications 4. Regional Development 5. Engineering Science and Technology in South Africa 6. International Liaison 7. State Liaison 8. Management and Administration.

Jan 1, 2001

By Ruiling DU, Jiazhi Zhang, Yong Zhao, Keng Wu

Reaction kinetics of metallurgical physical chemistry which was successfully applied in metallurgy (as ferrous metallurgy, non-ferrous metallurgy) became an important theoretical foundation for subject system of traditional metallurgy. Not only the research methods were very perfect, but also the independent structures and systems of it had been formed. One of the important tasks of metallurgical reaction engineering was the simulation of metallurgical process. And then, the mechanism of reaction process and the conversion time points of different control links should be obtained accurately. Therefore, the research methods and results of reaction kinetics in metallurgical physical chemistry were not very suitable for metallurgical reaction engineering. In order to provide the definite conditions of transmission, reaction kinetics parameters and the conversion time points of different control links for solving the transmission and reaction equations in metallurgical reaction engineering, a new method for researching kinetics mechanisms in metallurgical reaction engineering was proposed ,which was named stepwise attempt method. Then the comparison of results between the two methods and the further development of stepwise attempt method were discussed in this paper. As a new research method for reaction kinetics in metallurgical reaction engineering, stepwise attempt method could not only satisfy the development of metallurgical reaction engineering, but also provide necessary guarantees for establishing its independent subject system.

Jan 1, 2015

By James M. Link

Underground coal mining is the most hazardous industrial occupation in the United States.. Haulage accidents in underground coal mines contribute substantially to the occupational hazards of this type of work. In an effort to improve mine safety, a completely hydraulic transport system has been designed to move coal from the mine face to the preparation plant. The capital investment for the hydraulic haulage system is great, and the size of the mine developed for this study is large. Mine production for the conventional haulage mine is 1. 1 million tons of clean coal per year, while the hydraulic haulage mine will produce over 1.6 million tons of clean coal per year. Safety statistics for a number of mines of this size are shown.

Jan 1, 1975

By R. M. Kear

Strategic and tactical planning are both required in the mining industry but have completely different objectives and require different environments. If these are not fully understood, then the best value for a mining operation may not be realized. This paper examines the differences in these approaches and how they interface in the mining environment. The objectives, content, skills required and the implied management issues for these two components are examined with the hope that this will assist management and the planning teams in defining their respective roles and expectations. The opinions are those of the author based on his experience on several mining operations and projects.

Jan 1, 2006

By R. Butcher

Mud rushes are hazardous occurrences that have occurred frequently in mines in South Africa, and have been the cause of numerous fatalities in the past. Mud rush incidents not associated with accidents are believed to be common occurrences that are not generally reported. Many such incidents are probably associated with the operation of chutes and box fronts. This paper describes the conditions necessary for mud rush occurrences, postulated mud rush mechanisms, and methods of combating the mud rush hazard.

Jan 1, 2005

By Robert F. Chaiken

The Bureau of Mines is using model ducts lined with coal to study the nature of coal mine fires, their rate of propagation, their influence on ventilation airflows, and their response to sealing and other fire suppression measures. For scale-modeling purposes these studies are being carried out in various size ducts; eventually they will include a full-size mine entry in the Bruceton multiple-entry Experimental Mine. To date, work has been carried out in an insulated 9.l-m-long duct with a 5-cm thickness of coal leaving a 23-by 23-cm square opening for air ventilation. Fire propagation processes in this duct were mainly transient in nature owing to the relatively small length-to-diameter ratio. This report describes the experimental equipment employed and the results obtained to date.

Jan 1, 1979

By H. Kenworthy

This report concerns cooperative milling investigations of the Central mill of the Eagle-Picher Mining &. Smelting Co, The work carried on at the Central mill and the Rolla, Station shows that: It is possible to reduce the Central mill heavy-medium plant tailings by 0.05 to .15 percent zinc; the 3/16-inch to 10-mesh fraction of the jig feed can be treated by sink-float to obtain a tailing containing only half as much zinc as the jig tailing; Humphreys spiral concentration of the flotation tailing does not recover enough zinc to be economically attractive; and crushing and wet grinding of ferrosilicon for heavy medium are commercially feasible. The Eagle-Picher Co. operates extensive mines in the Tri-State area of Missouri, Kansas, and Oklahoma. The ore is milled at its Central hill, which also accepts custom ores. During the recent war the mill handled about 12,-000 tong- of low-grade ore per day. The company milled about 50 percent of the district tonnage and purchased nearly 90 percent of the custom ore. About 50 percent of the mill feed was from company mines. Zinc is the chief value in the Tri-State ores,-with Varying quantities of lead and cadmium minerals, as well as small amounts of germanium and gallium.

Jan 1, 1949

By K S. Fisher, J D. Pease

The installation of the George Fisher flowsheet in the lead/zinc concentrator at Mount Isa Mines Limited has recently been completed. The George Fisher flowsheet involved moving flotation capacity from the lead circuit to the zinc circuit and changes in zinc circuitry, changes in the reagent regime and increased regrinding capacity, using IsaMills, to regrind some streams to 80 per cent passing seven microns. The project was highly successful, delivering a five per cent increase in zinc recovery within a fortnight of commissioning. The George Fisher flowsheet was developed over six years. Laboratory work built upon the knowledge gained from investigating and processing the Mount Isa and Hilton orebodies. The engineering design and construction for the brownfield expansion of the existing lead/zinc concentrator had significant involvement from the operational, maintenance and technical personnel. Experienced personnel were seconded from the concentrator to the design and construction groups to ensure smooth integration of the new flowsheet into the existing concentrator with minimum downtime, and maximising the reuse of existing equipment. The combination of thorough design, good project integration with operations, and a good commissioning plan allowed almost immediate delivery of project gains. The project was highly successful, the full design improvements were achieved within two weeks, allowing the focus to move to developing future improvements.

Jan 1, 2000

By Lance McAnuff

The year 2001 coincided with the forty-fifth year of blasting-control specialization by the author. Commencing with the construction of the Saint Lawrence Seaway System in 1956 and continuing until the present time this career has spanned one of the most progressive and exciting periods in the still relatively short history of commercial blasting. The paper touches upon a number of the more interesting projects with which the writer was involved during those early days, including the removal by explosives of “Ripple Rock” the infamous underwater hazard to shipping which at one time inhibited ocean traffic along the Inside Passage between Vancouver Island and the mainland of British Columbia, Canada’s most westerly province. Various assignments involving incidents from devastatingly ,tragic to comically absurd are described, along with personalities encountered along the away, most of them readily recognizable as giants in the field of explosives engineering. Various stages in the evolution of state-of-the-art explosive products, initiation systems vibration monitoring equipment and limiting criteria are compared and some of the effects these have had on safety and productivity during the last forty-five years are analyzed.

Jan 1, 2002

By F. T. Cawood

The new South African Mineral Policy has major implications on the way mineral rent will be collected and shared between the stakeholders in future. Although the policy does not supply details on how this will be done, drastic departures from practices under the previous dispensation require a new approach. For example, there introduction of the ?right to mine? principle implies that the repealed lease consideration concept will be expanded to all minerals. The new policy also makes provision for predetermined standard terms and conditions for all prospecting and mining permissions. It also states that, regardless of whether the mineral rights are state or privately-owned, all prospecting fees and mineral royalties will be determined by state officials after consultation with the registered holder of the mineral rights. This paper proposes a standard mineral royalty formula that complies with the principles mentioned in the White Paper and has been shown to be internationally competitive.

Jan 1, 2001

By A. Swanson

The Australian coal industry has been subdued in recent years and only a few new plants have been constructed, but the drive for greater efficiency has seen continued technological developments. The paper lists the new plants and major upgrades, plus summarizes technical developments in the areas of dense medium processing, fine coal treatment, froth flotation, dewatering and on-line analysers.

Jan 1, 2001

By G. S. Hume

Introduction Core drilling of the bituminous sands of northern Alberta has been carried on by the Mines and Geology Branch, Department of Mines and Resources, under the supervision of the Director, W. B. Timm. This was part of the Dominion Government's wartime investigations, which included an agreement with Abasand Oils, Limited, for the study of commercial possibilities of obtaining oil from the bituminous sands. The drilling programme, commenced in 1942 by the Consolidated Mining and Smelting Company of Canada, was continued in 1943 and subsequently by Boyles Bros. under contract with the Mines and Geology Branch. Several areas have been investigated and one of these, the Mildred-Ruth Lakes area, ' herein described, is of special importance in that it contains a sufficiently rich and large deposit of bituminous sands and bitumen beds to warrant consideration of commercial developments for the production of oil. The Steepbank Area, East Side of Athabaska River The Steepbank area, on the east side of Athabaska river in township 92, about twenty-two miles north of Fort McMurray, was selected for drilling in 1942 because previous investigations by Ells indicated it was one of considerable promise both from the standpoint of having reasonably rich bituminous sands under relatively light overburden and also having an excellent tailing disposal and plant site for large-scale operations in proximity to Athabaska river. The drilling done in 1942 and 1943 was largely exploratory, and, when it was found that the southerly part of township 92 had only low-grade material, closer drilling was done in 1944-45 in the richer, more northerly part.

Jan 1, 1947

This report is the 21st in a series summarizing research and technologic work on coal and related investigations by the Federal Bureau of Mines - the Chard of the series published on a calendar-year basis 2/ Subject publica¬tions of the Bureau during 1956 are cited, and pertinent Bureau work is described briefly. The most effective method of conserving our important coal reserves is through improved technology of production and utilization. Associated problems form the program of the Bureau.3 4 5 6/ Potential production is depend¬ent on a knowledge of the quantity and quality of the reserves, and the Bureau continues to contribute information on this subject. Many problems are being studied that relate to improvements in current production, including mining methods and health and safety measures. Preparation of mined coal is necessary for its most efficient utilization. Preparation by conventional methods is being studied, as well as the development or new methods. Fundamental studies on the structure and properties of coal are necessary to insure full advantage of the special qualities of different coals. Controlling factors in the efficient use of coal in combustion, carbonization, gasification, and direct and indirect hydrogenation of coal are being studied continuously, and new processes are being investigated. The many advances in all these fields are discussed.

Jan 1, 1959

By Edwaldo Ferreira Brandão

Os aços avançados de alta resistência (Advanced High Strength Steels - AHSS) vêm sendo uma solução atrativa na construção de estruturas automotivas mais leves e seguras, pois combinam alta resistência e boa conformabilidade. Neste trabalho, foram realizadas simulações numéricas e experimentos em escala industrial, com aços fornecidos pela Usiminas, da estampagem de uma travessa dianteira de suspensão automotiva. O objetivo desses experimentos foi avaliar a estampabilidade deste componente, que atualmente é fabricado com o aço de alta resistência baixa liga (HSLA340, 2,0 mm), quando substituído pelos aços Dual Phase (DP600, 1,6 e 1,8 mm) e Transformation Induced Plasticity (TRIP700, 1,6 mm). As simulações numéricas reproduziram o padrão de deformação destes materiais durante os processos de conformação e o perfil geométrico do componente. A travessa de suspensão automotiva foi estampada com sucesso com os AHSS propostos.

Aug 16, 2017

By H. Simonsen

Risk assessment consists of a search for the answers to: ?What can happen? ?How likely it is that it can happen? ?What are the consequences if it does happen? Perhaps the most important aim of risk analysis is to predict the likelihood that a planned profit will be achieved over a given period of time. A typical risk model employed for this purpose includes a stochastic connection between the dependent variable of an expression that describes a process and independent variables represented as random quantities. The output will be a probabilistic distribution. The uncertainties in a planned mining operation include: ?Commodity market characteristics, particularly price ?Ore reserves and mineralogical composition ?Mining method ?Process performance ?Capital and operating costs ?Schedule duration ?Economic environment effects. The processes employed in the probabilistic estimation of a project?s outcome include both Monte Carlo simulations and simulations where variable correlation is considered important. The risk model, once developed and tested, provides a framework for a rational approach to risk analysis and the testing of alternatives.

Jan 1, 1999

By Charles L. Kimbell

Virtually every available measure of total world mineral industry activity demonstrated that 1982 was little, if any, better for the industry than 1981 had been. Levels of production, trade, and consumption for virtually every major commodity declined; unit prices for most commodities fell, particularly in terms of constant dollars, and as a result of cutbacks in output and lower prices, capital available for investment within the industry was reduced. These conditions, coupled with the existence of considerable idle capacity, tended to retard investment, although there was an upturn in U.S. oil industry investment overseas. Despite the overall depressed situation of the world's mineral industry, there were indications of possible improvements in market economy countries near yearend, as output of some materials increased marginally and as prices for some mineral commodities reversed their downward trends. The downturns in total world mineral industry activity were not universal from the viewpoint of individual countries. Indeed, output of a number of commodities increased in centrally planned economy countries, and these gains were insufficient to offset declines in market economy countries, thereby sharply altering the proportion of total world output accounted for by each of these two groups of countries. There was a similar shift in consumption on a percentage basis.

Jan 1, 1984