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By L. R. Chimimba

"The Trojan nickel deposit occurs within a pile of ultramafic lavas subjected to a lower amphibolite grade of metamorphism. The lavas form part of the Upper Greenstones (Bulawayan Group) of the Mazoe greenstone belt. The nickel mineralization occurs as disseminated, massive and near-massive sulphides. The massive and near-massive ore occurs along the basal contact of the serpentinite units and is overlain by the more abundant disseminated ore, which occurs within the serpentinite. The main sulphide minerals are pyrrhotite. pentlandite and chalcopvrite. Minor amounts of millerite and pvrite are present. The Ni : Cu ratio in all three types of ore averages 15:1.The intercumulus nature of sulphides in the near-massive ore and similar textures occasionally seen in the disseminated ore indicates a magmatic origin of the mineralization. The basal position of the near-massive and massive ore suggests that the sul­ phides settled out under gravity during the emplacement and crystallization of a peridotitic magma. The deposit has been deformed and some of the primary massive ore has been remobilized into veins and breccias. The disseminated mineralization now occurs mainly as blebs of sulphides intergrown with silicate minerals or as stringers of sulphides between foliation planes in the serpentinite."

Jan 1, 1984

By J. R. Hammond, I. C. Herbert

Report of discussion at October, 1970, IMM general meeting (Chairman: M. J. Cahalan, President) and contributed remarks on the paper published in Transactions/Section C (Mineral Processing & Extractive Metallurgy), vol. 79, June, 1970, pp. C128-36 and introduced by I.C. Herbert. Contributors were von Struve G., on the application of balling discs and the use of basic additives; Young P.A., asking for details of the drying, grinding, balling, induration and specification testing equipment and processes; Davison J. on pellet swelling properties and Carter G.C. on disc operation, refractories and green ball properties.

Dec 1, 1971

By J. Gough M. D.

There are many points still obscure regarding the nature of coal-workers'- pneumokoniosis, but the interpretation of the disease has been greatly clarified in recent years. It is now known that exposure to fumes or gases or other conditions peculiar to coal-mining are not necessary factors in the production of pneumokoniosis. The same disease occurs in coal-trimmers working in the docks, and it is thus established that the inhaled dust is the primary factor. On the other hand, there is no completely satisfactory explanation of the distribution of the disease. Geological and petrological studies have not given an unequivocal explanation of the difference in incidence in different parts of the coalfield. It is an open question whether the quantity of dust inhaled is more important than its chemical composition. However, there is ample evidence from the medical side that elimination of dust and of tuberculosis from the environment of coal workers will be required to prevent pneumokoniosis. Much is being done with regard to elimination of dust, and a similar energetic action is required in regard to tuberculosis.

Jan 1, 1947

By T R. Marrero, J W. Wilson

This paper presents costs for a coal log pipeline that can transport coal over distances from 50 km to 1500 km. The coal log pipeline (CLP) concept is a new technology in w hich coal is compacted into water impermeable circular cylinders that can be suspended in water flowing through an underground pipe. CLP includes processes to prepare the run-of-mine coal for compaction, the injection of coal logs into a pressurised water-lilled pipeline, the conveyance of the coal through a pipe including special pumping stations, and the treatment of the coal logs and water at the pipeline outlet. An 8 inch (203 mm) pipeline can transport more than 2 Ml of coal per year. CLP components have been extensively tested in bench-scale facilities where these tests have included start up/shutdown steady state flow behaviour, end of pipeline treatment of water and coal log handling, water hammer effects, abrasion of logs and pipeline, coal log manufacture, and other engineering operations. Several sites are being considered in the United States (US) for the first commercial demonstration that will probably take place in 1998. The cost calculations are based on realistic values for all the components of a CLP. including a return on investment. For pipelines of different diameter, values for coal transportation are presented in terms of $(USVtonne as a function of distance.

Jan 10, 1996

By Fearnside W. G.

Further discussion at the Midland Institute of Mining, Civil, and Mechanical Engineers' general meeting held in Leeds, March 21st, 1916, with T. Beach, vice-president, in the chair, of a paper published in Trans. Inst. Min. Engrs., 1915, vol. L, p. 573 and discussion vol. L., p. 109 and 608, comprised a brief written contribution by Faulds A.

Dec 1, 1916

By Garforth W.

The chairman announced the new government duties of the out-going President, Sir Thomas Holland, and the formation of a new standing committee on mining to advise the Advisory Council for Scientific and Industrial Research on suitable projects for grants. Some of the potential lines for investigation into the best methods of winning and presenting coal in the best commercial condition include wasteful practices in operating steam boilers, national loss due to neglecting recovery of coal by-products, and the leaving of large areas of coal for fear of spontaneous combustion or as boundary pillars and support

Dec 1, 1916

By D. L. Buchanan, M. J. Jones

In May, 1982, the University of Western Australia in Perth hosted a three-day international conference on nickel sulphides, followed by a ten-day field excursion to the Western Australian nickel sulphide deposits. The conference was arranged by Professor D. I. Groves, C. M. Lesher and Dr. R. E. T. Hill under the auspices of the International Geological Correlation Programme's Projects 161 ("Sulphide deposits in mafic and ultramafic rocks") and 91 ("Metallogeny of the Pre- cambrian"). This volume contains a selection of the papers that were presented at the Perth conference. Most of the papers are related to the nickel sulphide deposits of Western Australia, but contributions with settings in North America, Finland, Vietnam and Southern Africa have also been included.

Jan 1, 1984

By Ruddle R. W.

Although copper has been smelted for many years, relatively small attempt has been made in the past to examine the fundamental physical chemistry of the processes involved. Therefore, technological developments apart, slow progress has been made with the development of improved or new principles of smelting. The methods at present in use in the majority of the world’s smelters are essentially those employed at the beginning of the present century; it is significant that many of the textbooks on copper smelting, written some 50 years ago, are still regarded as standard works. The book is divided into seven chapters. In the first the fundamentals of modern smelting processes are briefly outlined for easy understanding of the subsequent sections, while the next two chapters are confined to the more theoretical aspects of the constitution of mattes and slags. Some problems of considerable practical importance are discussed in the remaining four chapters; these are (1) magnetite formation, (2) copper losses during smelting, (3) the recovery of sulphur from the smokes produced during smelting, and (4) the elimination of impurities. A collection of thermodynamic data relevant to copper pyrometallurgy is presented in an appendix, and, for the convenience of readers not well acquainted with thermodynamics, a brief explanation of the thermodynamic terms and methods employed is given in a second appendix

Jan 1, 1953

By Fergusson E.

An account is given of the history and operation of the Straits Tin market and the Penang price. The procedure by which the official ruling tin price is determined is presented and the way in which bids are treated is outlined: the price declared in Penang is the result of a joint operation by the two Malaysian smelters and is arrived at by finding the highest price at which the whole of the day's offerings for sale can be sold, thus reflecting the marriage of the offerings of the individual mine producers with the demand for Straits Tin from the consuming countries of the world. A system of accurate weighing, sampling and assaying of concentrates delivered to the smelters' premises enables the various ore-buying agencies of the two smelters to notify their central offices promptly of the estimated tin content of the concentrates their customers wish to price that day, so that by 11.00 a.m. both smelters will have exchanged with each other figures giving the total quantity of metal they have for inclusion in the day's market, at the same time exchanging particulars of the bids they have received. Miners are encouraged to sell regularly for cash and an evenness is thus achieved which avoids large daily fluctuations in overall quantity.

Dec 30, 1971

By Winmill T. F.

Among the various theories proposed to account for the spontaneous ignjtion of coal, one which has at times been very strongly held is that the initial heating is due to the oxidation of iron pyrites. From the results described in this paper, it is possible to calculate roughly the rate of spontaneous heating of a specimen of finely-divided pyrites, on the assumption that all the heat developed is used in raising the temperature of the pyrites, and that none is lost. It is clear that where finely-divided pyrites occurs in considerable proportion among coal, it may be the chief factor in originating combustion, but that pyrites can only be the cause of a heating when it is present in considerable proportion, and in a very finely-divided state

Dec 1, 1916

By C G. Wall, T S. Daltaban

Three quarters of recent increases in world oil reserve estimates since 1990 have been attributed lo ‘better reservoir management' rather than to new discoveries. For the United Kingdom Continental Shelf (IJKCS), the Department of Trade and Industry (DTI) has on 2.2 bn barrels of extra oil protection through effective reservoir management of existing producing reservoirs. Past practise has been to manage petroleum exploitation on a departmental basis, with exploration assessing and ranking prospects, reservoir engineering assessing development plans and production facilities implementing plans. Any reservations necessary might involve restarting the project evaluation from scratch. Current practice is to manage an operation through asset management teams involving all disciplines. It is hoped that this approach will not only eliminate fruitless directions of effort, but the quality of work in each discipline will benefit from interaction. That is, the result of a team effort is greater than the sum of individual efforts. To date, this is most apparent with the interaction between geology, reservoir geophysics and reservoir engineering through reservoir characterization. This is the current area of greatest effort, with improved geophysical technology and computer power leading to more and more detailed and complex simulation models. The equally important interaction of reservoir engineering and production and facilities engineering applied to fields in decline has not yet achieved the prominence that it deserves. Establishing priorities in reservoir management requires the very critical evaluation of the relative value of objectives. The fact that something can be done (3-D seismic, 4-D seismic, multilateral wells, or three phase multi-layer well test analyses etc) is not a good reason for doing it. Reservoir management should he a study of value added versus cost for any activity possible or proposed. Both in the areas of reservoir data acquisition and of assessing opportunities in the period of production decline, it is likely that expert systems will need to be developed with the associated base of experience, understanding and know ledge. A n other area for the future is the elusive target of ‘enhanced ’ oil recovery, as distinct from ‘improved’ oil recovery. The most likely route forward here is the incessant scrutiny of reservoir regions and units within fields for their suitability for pilot schemes for advanced recovery techniques implemented at a favourable time. Finally, the reduction of costs, the maintenance of low. but viable rates of production and the threat of abandonment costs will increase reserves. An increase which may have appeared insignificant in the past is now more valuable.

Jan 11, 1996

By Mowat D. M., Louis H., Smith W. Mackey W. M., Dron R. W., Ellison C. C., Winmill T. F., Kerr G. L., Haldane J. S., Ashworth J., Garforth W., O'Shea L. T.

Discussion of Winmill's paper, including various anecdotal examples, is presented together with the author's response; topics included: the need to distinguish cubic pyrites from the rapidly decomposing rhombic form known as marcasite; the effects of moisture content in the coal and air; the possible effect of pressure; the heat insulation resulting from heap/stack size; and the means of determining pyrite and moisture contents

Dec 1, 1916

By S. Y. Ezz

Report of discussion at February, 1971, IMM general meeting (Chairman : M. J. Cahalan, President) of a paper published in Transactions/ Section C (Mineral Processing & Extractive Metallurgy), vol. 79, September, 1970, pp. C226-C233 with contributions by Wild R. and Astier J. on fluidised bed reduction of iron ore fines

Dec 1, 1971

By G. B. Hooper, G. A. Ferguson

The technical capabilities and user-friendliness of the major computer-aided mining design software systems are reviewed. Recent experiences with three systems are outlined to indicate the practical problems that arise. The examples were: Microlynx software from Lynx Geosystems at the Great Dyke platinum mine in Zimbabwe; Lynx software from Lynx Geosystems at a copper mine in central Africa; and PC-MINE software from Gemcom Services at an open-pit gold project in Western Australia. Difficulties in the use of mining design software has led to an alternative approach. Falconbridge, Canada, has developed an integrated mine-planning system on a CAD platform that encompasses ore reserve estimation, stope design, development layout and survey control. Future directions of computer-aided mining design using this basis are discussed. A major advantage of using mainstream software packages, such as spreadsheets, databases and CAD programs, is that most engineers and geologists are experienced in handling such systems in the normal course of their work.

Jan 12, 1992

By P. Danson, D. A. White, S. Bashir

Composite ion exchange materials made of SnO2, TiO2 and MnO2 can be used to remove radioactive contaminants from nuclear waste streams. In several cases their selectivity and capacity are enhanced by mixing hydrous silica into the matrix. MnO2-SiO2 materials are especially useful for a number of reasons, such as their selection of heavy elements over caesium. Distribution constants and determinations of exchange capacities show that in many instances the properties of the composites are better than those of the oxides alone, while the presence of a chelating agent has been found to reduce the uptake of nuclides considerably. Methods are being developed for the bulk manufacture of the materials. Further work on sorption mechanisms is required to explain anomalous results, particularly the variation in exchange capacity for different elements and the ability of the oxides to sorb colloidal material in alkaline solution.

Jan 8, 1992

By S. V. Shiraishi, H. B. Bell

Report of discussion at February, 1971, IMM general meeting (Chairman: M. J. Cahalan, President) of a paper published in Transactions/Section C (Mineral Processing & Extractive Metallurgy), vol. 79, June, 1970, pp. C120-C127, with a contribution by Wright P.A. on the miscibility gap

Dec 1, 1971

By C. P. Summerhayes, J. W. G. Gilbey, S. Henley, G. P. Glasby, J. J. T. Harvey, J. Larsson, O. Akiman, A. G. Brown

Abstracts are presented from six University of London, one University of Nottingham and one University of Durham PhD theses

Dec 1, 1971

By Gibson J.

Further discussion at the North of England Institute of Mining and Mechanical Engineers' general meeting held in Newcastle-upon-Tyne, 3rd June 1916, on the paper published in Trans. I.Min.E., vol.LI, 1916, p.72-84, included a written contribution by Parfitt I.C. and the author's written replies to this and previous discussion

Dec 1, 1916

By P. Beauvais

Philip Beauvais, from the Met Office's International Mining and Agriculture Department, explains the need to understand the impact of the weather and climate when developing future mine sites.

Mar 1, 2015

By A. J. Beer, A. Wetherelt

Paper presented at the UK minerals industry conference held in Leeds, UK, 3-5 April 1995. Camborne School of Mines has developed a simple, cost-effective light-sectioning method that has been used successfully in tunnels and small stopes. Light sectioning provides an almost visual examination of the stope's excavated profile. An illuminated section of walls, roof and floor is recorded photographically. Overbreak and underbreak can then be easily quantified by reference to the designed shape. The prototype rig is described. Use of a fish-eye lens to capture a greater field of view is discussed. Calibration was achieved by comparison with images made with a conventional wide-angle lens with nominal distortion. The system is reliable under a range of operating conditions including dust, heat and humidity. It is also simple and easy to use, does not require skilled personnel and is low cost

Jun 18, 1905