Search Documents

By M. D. Pritzker

Shrinking-core models are used to describe the physico-chemical processes that are associated with many metallurgical gas-solid and liquid-solid reactions. The models can be used to evaluate rate constants and effective diffusion coefficients from experimental data. This work generalises the model for diffusion through a product layer to cases where the transport of more than one species is rate-controlling

Jul 1, 1991

By L Casari

A study of samples from three sectors of the mine, which was worked from Roman times to 1991, revealed different textures, mineral associations and distributions of trace elements in the sulphides. In the last decade before closure, grades of sphalerite concentrate were in the range 51.67-53.30% Zn and 2.21-2.86% Pb and of galena concentrate 69.43-71.62% Pb and 4.70-8.36% Zn, while the estimated by-product germanium content of sphalerite concentrates sold was 300-400 g/t. Passing the different run-of-mine materials through the same concentrator flowsheet produced middlings and tailings during the preconcentration processing. Separate and alternative treatment of run-of-mine products would have yielded improved recoveries of sphalerite and galena and better values of by-product germanium and cadmium

Jun 18, 1905

By Fearnsides W. G.

Discussion at the The Midland Institute of Mining, Civil and Mechanical Engineers' general meeting held in Doncaster on 27th May 1916, on the paper published in Trans. I.Min.E., vol.LI, 1916, p.409-448, included oral contributions by Lupton A. on the mechanisms of subsidence and water egress and by Kendall P.F. on the validity and accuracy of the contour extrapolation technique and the effect of major faults, together with the author's response

Dec 1, 1916

By R. Vikram

IMAGES (Integrated Mapping Applications Graphical Evaluation System) is a computer graphics system developed by British Coal for mine planning. The objectives of the system are to increase the profitability of mined coal through a combination of direct and indirect benefits. The system is flexible and can be used in part or in full at a mine as a stand-alone system or as a remote location of a central corporate system.

Jan 12, 1992

By Emanuel Shinwell, Douglas Hay

"Opening statements relating to the health and welfare of underground workers and the nature and prevention of silicosis and pneumokoniosis. During 1945-47, 10,500 UK coal-miners were certified by the Silicosis Medical Board to be suffering from pneumokoniosis and suspended from work in the industry. Over 80% of cases occurred in the South Wales coalfields. Silicosis and pneumokoniosis also occur among metalliferous miners, such as the tin-miners of Cornwall. The slate-quarries of North Wales are also troubled by these conditions as are the haematite mines of the North-West of England."

Jan 1, 1947

By T. A. A. Quarm

The concept of a continuous zinc smelting process which employs submerged combustion of coal char for both heating and reduction is described. An estimate of the results of smelting a marmatitic zinc concentrate indicates that both the operating and construction costs would be lower than those incurred in processes now in commercial operation. The results of smelting a complex zinc-copper concentrate are also estimated, but no simple commercial process exists with which they can be compared

Dec 1, 1971

By Mavor S.

Further discussion at the Mining Institute of Scotland's general meeting held in Edinburgh, 12 February 1916, with D.W. Mowat, president, in the chair, of a paper published in Trans. Inst. Min. Engrs., 1915, vol. L, p.625 and discussed vol. L, pp.92, 433, 468, and 704 included comments by Mowat D.W. and the author's reply

Dec 1, 1916

By M. Riddell

This paper describes the incipient heatings that occurred below ground in the High Main and Main seams at the mine between the years 1963 and 1966. The possible causes, effects and activities associated with such heatings are discussed in an attempt to establish the precautions necessary to minimize such occurrences. The assessment of as many "norms" as possible is made to enable the earliest detection and level of activity to be determined.

May 23, 1905

Summary of the morning's events with a Written Contribution to Paper No. 4 and author responses

Jan 1, 1947

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

By D. J. Allan, W. R. Wilson

For conventional aerospace aluminium alloys of the 2000 (copper) and 7000 (zinc, magnesium) series the recycling of process scrap from both metal suppliers and aircraft manufacturers is a well-established, worldwide industry. The recent introduction of a new family of alloys that incorporates lithium has posed a new challenge to the recycling industry owing to the high cost of lithium, its high reactivity to the atmosphere and to refractories and its absence from the specifications of all other registered alloys. Various process options for recycling have been identified, but vacuum distillation has been selected as the most cost-effective and technically feasible solution. Experimental work established that the separation of Li from AI-Li scrap is feasible and an industrial process has been designed. The economics of Li recovery are very sensitive to the AI-Li content of the feed material. Owing to the design of aerospace vehicle manufacturing plants it is expected that the swarf will be mixed with other alloys. A method of enriching this feed has been developed that is based on the control of swarf morphology by thermal and mechanical treatments as a precursor to eddy-current separation. After eddy-current separation and vacuum distillation small proportions of Li are retained in the AI residue. The effects of this on the properties of conventional AI-Si shape-casting alloys were investigated and safe threshold levels have been established.

Jan 4, 1993

Jan 1, 1947

Jan 1, 1947

Jan 1, 1947

By R. Phillips

The low concentration of diamond in workable deposits requires very large samples for grade estimation, and results, even then, may be erratic and difficult to interpret. Although the Poisson probability distribution cannot accurately describe the occurrence of diamond, it is suggested that it gives a better estimate of grade than conventional methods, even from single samples. Examples illustrate the simple calculation required.

Dec 1, 1971

By W. Doherty, P. C. Lightfoot, V. A. Fedorenko, N. S. Gorbachev, V. I. Kunilov, A. J. Naldrett, Z. Johan

Paper presented at the conference Economic geology in Europe and beyond II, models for mineral deposits in sedimentary basins, held in Keyworth, UK, 13-14 April 1994. A model is presented which regards the Lower Talnakh- and Talnakh-type intrusions as part of the plumbing system for the overlying lavas. As magma ascended along the Noril'sk-Kharayelakh fault it was forced to spread out within sedimentary strata immediately beneath the obstruction of the accumulated volcanic sequence. Here it was severely depleted in chalcophile elements by sulphides, which were then trapped by their high density and remained behind in the main arteries to form the central, elongated zone of maximum thickness. Subsequent magma also lost Ni, Cu and PGE to the sulphides as it flowed through. The Lower Talnakh-type intrusions represent part of the plumbing system that became blocked at an early stage, before the influx of much mokulaevsky-type magma rich in chalcophile elements. The model accounts for the high metal content of the ores in comparison with the size of their associated intrusions, the extensive metamorphic aureoles, the chalcophile depletion of some overlying volcanic suites, the presence of the ore in near-surface intrusions rather than deep magma chambers, and the sulphur isotopic composition of the ore

Apr 1, 1995

Jan 1, 1947

Discussion of the paper presented at the North Staffordshire Institute of Mining and Mechanical Engineers' general meeting held in Stoke-on-Trent, March 27th 1916, with Mr. John Gregory, President, in the chair, included contributions by Gregory J., Cadman J., Hartley J.W., Wain E.B. and Henshaw A.M., followed by the author's reply

Dec 1, 1916

Further discussion at the Mniing Institute of Scotland's annual general meeting held in Glasgow, 8th April 1916, of the paper published in Trans. I.Min.E. vol li, 1916, p.169-186 with discussion p.187-188, included oral and written contributions by McLaren R. and Waddell H.

Dec 1, 1916

By K. El-Barawi, Hussein M. Kamal

Chlorination was performed of iron-rich chromite ore from Barramyia, United Arab Republic (UAR), together with its concentrate. The effects of change of grain size, chlorine gas flow rate, time and temperature were studied. The extent and mechanism of chlorination were followed through chemical and structural analyses of the feeds and complete chemical analysis of the chlorination products. By conducting the chlorination process for short periods at 600°C or lower temperatures, products having high Cr-Fe ratios suitable for ferrochrome production can be obtained.

Dec 1, 1971