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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

"A film entitled ""It Can Be Done! "" was shown depicting conditions of work in an anthracite mine in South Wales. Shots of the research laboratory and the taking of dust samples were shown."

Jan 1, 1947

By Schwartz M.

Madagascar's democratic election has led to a return to its position as a preferred trade partner with the USA and a priority market with Canada. Michael Schwartz takes a look at two key mining projects in this recently reinvigorated country

Feb 1, 2015

By R. H. . T. Garnett

Contributed remarks on paper published in the Transactions, Mining industry section, vol. 100, September- December 1991, A121--45

Jan 12, 1992

By P. Rama Krishna, B. Narasimha Rao, P. Ali i Peera

Induced polarisation (IP) surveys are commonly used in uranium exploration programmes in India. The IP method is effective in detecting the disseminated metallic sulphides that are often associated with uranium minerals. However, conductive and polarisable host rock or overburden often introduces inductive or electromagnetic (EM) coupling into time domain IP measurements. This makes it difficult to distinguish between responses due to such coupling and those that might indicate economic mineralisation. Attempts must be made to remove the EM effects before the IP technique is used in drilling programmes. Transient decay curves which were recorded during field surveys at Pisnari were factorised using the Marquardt algorithm. Dispersion plots of the amplitudes and relaxation times of the composite exponential function enable a clear distinction to be made between the effects of EM coupling and those of mineralisation.

Jan 4, 1993

By A. Hemami

In order to automate the operation of mechanical loaders it is essential to have a knowledge of the forces that act on the bucket and of the trajectory that the bucket should follow. A trajectory for the cutting edge of a bucket is derived from studies of the forces acting during the scooping phase. The proposed trajectory has a minimum energy consumption and is simple to automate. It is determined initially by setting to zero certain components of the resistive forces to the bucket motion which would otherwise result in unnecessary work and consequent energy wastage. The method for finding the appropriate trajectory is discussed on the basis of the properties of the material to be loaded and the loader size.

Jan 4, 1993

Papers submitted at the 8 ordinary general meetings are listed and details given of the proceedings of the annual general meeting held on 20 May 1971

Dec 1, 1971

By D. J. Wall, T. D. Johnson, M. T. Parry, G. R. Heath

In coal-fired power stations coal is ground to a fine powder and then transported pneumatically at 25-30 m/s velocity to remote burners. Wear of the conveying pipework is a well recognised problem and traditional lining materials are Nihard and basalt. In many cases these are being replaced by alumina tiles in order to improve life and reduce the frequency of replacement. A programme of laboratory testing of candidate aluminas with AIO, contents between 85% and 99-5% has been undertaken and the results compared with field experience. This gives confidence in the erosion tests, which were designed to replicate most of the field conditions. However, it has not proved possible to draw correlations between the laboratory erosion rates and any of the materials’ bulk properties. SEM, TEM and microanalysis studies have therefore been made in order to look for microstructural aspects that could be influencing erosion rates and it has been shown that intercrystalline cohesion, the matrix phase and porosity appear to have most influence on wear performance. It is necessary to quantify these microstructural parameters if reliable erosion performance is to be obtained. This paper was read at the Institute of Ceramics Annual Convention at the University of Durham, April 1988.

Jun 12, 1905

By A. M. Marabini, S. Battaglia, M. Ciriachi

A computer program has been developed that produces graphic representations of the atomic structure of any crystallographic plane of a mineral. The information provided by the program relates to a purely geometrical model of the crystal structure in which each atom is represented solely by the x, y and z coordinates of its centre. Despite its simplicity, the program can be used as a first approximation model in studies of the interaction between mineral processing reagents and the surfaces of mineral grains which are assumed to be coincident with cleavage planes.

Jan 4, 1992

By D. A. White

A simple model for hydrocyclone classification based on the crowding theory first put forward by Fahlstrom is presented. This is a mechanistic theory that postulates that the behaviour of a hydrocyclone is the result of an ordered process that is independent of its dimensions. The main variables that describe the process are the fractions of feed solids and water that are ejected from the underflow. A simple model is developed from basic properties of the classification process and is compared with theory. Agreement is good but improves when the cyclone has a high solids content

Dec 1, 1991

By R. G. Jones

At its peak in the 1970s, South Africa was responsible for around 80% of global gold production and, according to the US Geological Survey, it still has the largest share of gold reserves - as well as 90% of the world's platinum. But, in January 2015, gold production reached a new monthly low, generating 87% less than it did in January 1980, and South Africa is now the world's sixth ranked gold producer. What next for African gold?

Jun 1, 2015

By P. J. O'Connor, V. Gallagher

The addendum, to the paper published in Trans. IMM B, vol.103, 1994, p.B175-B187, acknowledges data from Celtic Gold plc at Navan and apologises for the omission

Jun 18, 1905

By Dickinson C.

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.XLVIII, 1914, p.400, included brief oral contributions by Bragge G.S. and Hepplewhite W.H. with the author's responses regarding leakage and boring of cement into the coal

Dec 1, 1916

By P. K. Kaiser, R. K. Brummer

Paper presented at the conference Risk assessment in the extractive industries, held in Exeter, 23-24 March 1994. A risk-based decision-making procedure has been developed for selecting rockburst-resistant tunnel support in burst-prone mines. The method is based on a risk-cost-benefit analysis and uses support cost data, costs associated with the risk of support failure or excavation loss, costs associated with accidents, injuries and deaths, and the benefits achieved by installing rockburst-resistant support. It takes into account the risk of damage to the support systems due to rockbursts, potential loss of production and the need to rehabilitate in the event of a damaging rockburst. A practical example is provided to illustrate the principles involved in the decision process

Jun 17, 1905

By P. J. O'Connor, V. Gallagher

examined analytically in relation to the ratio of the

Dec 1, 1994

By D. L. Buchanan, ed. sci.

The issue comprises 10 contributions on PGE mineralisation, of which 9 were presented at the symposium organised by the IAGOD Commission on Ore Deposits in Mafic and Ultramafic Rocks and the BRGM-CNRS University of Orleans research group. The editor's introduction and summary of the papers is presented together with the title page, contents list and cover photograph of a harzburgite ridge, dunite boundary and chromite quarry in the Shetland ophiolite on Unst

Apr 1, 1994

By International geochemical

During the production of the Geochemical Atlas of Finland till samples were collected throughout Finland at a density of one sample per 300 km2. The material studied was the fine fraction of till (less than 0.06 mm). The geochemical mapping has shown that elements that are locally enriched in bedrock in the form of ore mineralisation are also enriched in a wide area of the surrounding till. These anomalous enrichments of ore elements take the form of rectangular or curvilinear zones that are some tens of kilometres wide and hundreds of kilometres long. The mineralised zones host ore deposits of different genetic types and can be termed "ore provinces". They stand out prominently on the geochemical maps and can be divided into sub-units of different chemical composition.

Jan 12, 1992

By K. M. Kinealy, A. R. Ramsden, D. H. French

A negative correlation exists between sphalerite composition and gold content when gold is transported as Au(HS)2(-); however, there are spatial and temporal differences within a single deposit. A previous model for the formation of volcanogenic massive-sulphide deposits within thermally intensifying and waning hydrothermal sytems in much the same way as is observed around modern sea-floor vents is supported. The results also emphasise that recognition of the mechanisms of gold transport in ancient deposits depends critically on an understanding of their mineralogy and stratigraphy

Jan 1, 1991

By T. Bennett

Geothermal energy has the potential to provide 20% of the UK's annual average electricity generation capacity requirement. This article discusses the costs and potential benefits.

Jun 1, 2015

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