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Discussion at the The Midland Counties Institution of Engineers' general meeting, held in Nottingham on 6th May 1916, included contributions by Bramall E., Bragge G.S. and Watkins W.G. regarding possible measures for reducing energy consumption in coal-winding and pumping by centralising engines, using exhaust steam, improving coal quality and size uniformity, or mechanical stoking

Dec 1, 1916

By H. L. Willett

The self heating of coal, or spontaneous combustion, has been a problem for centuries. This symposium addresses the issue.

May 23, 1905

By Thomas D. E.

Discussion at the Manchester Geological and Mining Society' general meeting held in Manchester, March 14th , 1916, with Leonard R. Fletcher, President, in the Chair, of a paper published in Trans. Instn. Min. Engrs., 1916, vol. L., page 482, comprised the author's written response to suggestions made in previous discussion

Dec 1, 1916

By Black J.

Further discussion at the The Midland Counties Institution of Engineers' general meeting held in Nottingham on 6th May 1916, on the paper published in Trans. I.Min.E., vol.L, 1915, p.449, included brief oral contributions by Bragge G.S., Hepplewhite W.H. and Binns G.J.

Dec 1, 1916

Jan 1, 1947

By D. J. Spottiswood, R. K. Tuteja

Axial grade profiles were analysed for a pilot column operating in reverse flotation mode to float talc from a gold-bearing sulphide ore. It was found that concentration gradients in the pulp are very low. Most of the cleaning action, both upgrading of valuable minerals and rejection of gangue, occurs in the froth zone

Jun 17, 1905

By R. T. Grant, C. Bazin, D. Hodouin

It is shown that most of the variation in the results of semi-batch flotation tests is related to the unavoidably stochastic nature of the flotation process. The preparation and analysis of flotation samples and, to some extent, operator error in performing the flotation test procedure are responsible for a small proportion of the observed variability of the calculated flotation performance indices

Jun 17, 1905

By G. E. Pearse, comp.

Questions from the conference delegates and replies by the papers' authors are summarised for sessions on hydropower, metro/rail and water/waste tunnels, tunnel-boring machines, environmental issues, research and case histories, design, and tunnel machinery, with reference to papers on tunnels in Lesotho, Nova Scotia, Italy, UK, Sweden, Kenya, Massachusetts, Germany, Norway, Taiwan, Switzerland, Greece, Malaysia, Australia and Texas.

Dec 1, 1994

By V. Distler, E. F. Stumpfl

Paper presented at the IAGOD international symposium on mineralisation related to mafic and ultramafic rocks held in Orleans, France, 1-3 September 1993. The massif contains large chromite bodies of "Alpine-type", ophiolitic affinity. Orebodies reach thicknesses of 150 m and sizes of more than 150 000 000 t chromite ore with average grades of 55-60 wt% Cr2O3. Chromites in the Main ore field are low-Al, high-Cr spinels which exhibit some variation in their Mg-Fe distribution. This differs markedly from high-Al spinels in peridotite host rocks and in narrow chromite pods which occur in the western and northern parts of the massif. Chromites carry silicate inclusions, often hydrous silicates such as amphibole. Chromites in massive chromitites contain micron size inclusions of platinum group minerals (PGM). Composite grains containing two PGM and, occasionally, a hydrous silicate are common. Os-Ir alloys rimmed by PGM sulpharsenides occur in narrow serpentine veinlets that cut chromite and are evidence for the reconcentration of PGE concomitant with introduction of As, probably during serpentinisation. Whole-rock PGE contents are highest in massive chromitites of Diamond Pearl mine (totals of 500 ppb). Chondrite-normalised PGE patterns of chromitites show negative slopes which are typical for ophiolitic, podiform chromitites in mantle sequences. The PGE patterns of host rocks are flat and rather depleted compared with those of chondrites and chromitites. Petrological data from unaltered host peridotites suggest a high temperature overprint leading to sub-solidus re-equilibration of olivine and spinel and to the growth of pargasitic and edenitic amphiboles

Jun 16, 1905

By L. D. Smith

Paper presented at the conference: Risk assessment in the extractive industries, held in Exeter, UK, 23-24 March 1994, and first published London: IMM, 1994, preprint volume. 22pp., 15 refs. The concept of risk is well established in the mining industry but it is difficult to provide a quantitative assessment of risk. A discussion is presented of the significant sources of risk in a mineral project and how they are addressed. The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed and a methodology for the analysis of risk levels is proposed which assesses the constituent components of the discount rate (real interest, mineral project risks and country risk)

Dec 1, 1994

Paper presented at the conference Risk assessment in the extractive industries, held in Exeter, 23-24 March 1994. Sensitivity analyses based on financial variables are now routinely applied to the forecast financial results of mining projects especially during the feasibility stage. Risk analysis is gaining acceptance but is still almost universally confined to the effects of variations in financial variables. The single most sensitive factor in almost all mining projects is the ore reserve, but it is either ignored or improperly used in sensitivity and risk analyses. Unlike financial variables, the components of the ore reserve (grades and tonnages of mining blocks) are a function of location within the orebody. Physical (mining) access to these components is therefore a function of time which has a crucial effect on forecast cash flows. It is critical that these fundamental concepts are included in risk analyses of mining projects. The effects are considered of the uncertainty of the ore reserve on feasibility studies and open-pit mine design for a small gold mining venture. Geostatistical simulation is used as a method of quantifying the risk in using grades and tonnages estimated from sparse data

Jun 16, 1905

Jan 1, 1947

By Black J.

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.449 included written contributions by Dron R.W., Riddell W., Hamilton J. and Mowat D.W.

Dec 1, 1916

By Dean S.

Further discussion at the The Midland Counties Institution of Engineers' general meeting held in Nottingham on 6th May 1916, of the paper published in Trans. I.Min.E., vol.L, 1915, p.179, included brief oral contributions by Bragge G.S., Lewis W.H. and Hepplewhite W.H.

Dec 1, 1916