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By D G. Jefferies

This paper covers National Grid's role in the electricity market, the growth of competition in both generation and supply in that market, and the resulting impact on fuel usage, prices and the environment. It also considers other, external influencing factors on the electricity supply industry, as well as the growing trend towards globalization.

Jan 12, 1997

By R. Scheepers, J. E. Misiewicz, A. C. Fitzgerald

Discussion by A.C. Fitzgerald of the paper, published in Trans. IMM A, vol.104, 1995, p.B121-B135, is presented together with the authors' response. Fitzgerald points out a number of problems with the idea of mineralising fluids leaving no trace in the large volumes of rock traversed before depositing all minerals of value in a particular horizon or rock type with which the required isobaric or isothermic surface also coincides. He suggested that in the case of the Rooiberg tin deposits, the Lebowa Granites may be batholiths that reached the surface and were capped by sheets of their own volcanics. The authors agree that they had considered a possible syngenetic origin for the stratabound deposits, explain that no conclusive evidence for this could be found, discuss the relative ages of the sediments and volcanics of the Rooiberg Fragment and explain the role of its low-intensity deformation and flat dip in the coincidence of an isobaric-isothermic surface with the lithological stratification

Jun 18, 1905

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 Winmill T. F.

Paper presented at the at the Institution of Mining Engineers' general meeting held in London on 8th June 1916: In a previous paper it has been shown that the rate of absorption of oxygen by coal is neither directly proportional to the surface area of the coal exposed nor to the percentage of oxygen in the air. Further experiments are now described supporting this conclusion

Dec 1, 1916

By R. N. Pryor, S. H. Shaw, D. L. Dowie, S. H. U. Bowie, M. J. Cahalan, S. F. Gandar

It is concluded that land-based mineral resources will be adequate for most minerals in the immediate future, but in the long term more minerals will come from offshore locations. Because the oceans are international and can transport pollution, international control of offshore workings will be necessary. In the UK and similarly highly developed areas, the working of low-value bulk minerals will create increasing problems in urban development and countryside preservation. Much more information should be published on standards to be adopted and their costs, if emotional social pressures founded on ignorance are to be avoided. The Town and Country Planning Acts have greatly improved the environmental quality in Britain in relation to mineral working. In the long term conservation of some minerals in short supply may be necessary on a national or international basis. Much research is required for the determination of adequate criteria and standards for the preservation of environmental quality in the mineral industry. New local, national and international legislation will be required and the adoption of voluntary standards by trade associations should be encouraged wherever appropriate

Dec 1, 1971

By R. R. Tatiya

The following procedure was used to determine cut-off grades: define the orebody profile; plan the stope layout and quantify the work involved; formulate equipment-performance norms; calculate unit costs; input process recoveries and metal prices; and calculate the cut-off grade. Use of the method is illustrated using data from a copper mining complex in India. Results from the study led to the following conclusions for underground mines in general. Cut-off dependent costs vary significantly with the stoping method employed, orebody thickness, the degree of mechanisation and the working efficiencies of the workforce and equipment. This applies even within the same deposit. Sub-level stoping and its variants can be operated at a lower cut-off grade than cut-and-fill and its variants. Thinner orebodies affect cut-off grades adversely, but with thinner orebodies very little further reduction in cut-off grade can be achieved once a certain minimum width has been exceeded. For the same stoping method and in the same mine the cut-off grade varies with the degree of mechanisation. Labour-intensive methods require higher cut-off grades. An allowance for working efficiency should be made when calculating cut-off grades. Higher process recoveries allow a significant lowering of cut-off grades

Jul 1, 1996

By M. A. Bussell, G. S. Camm

The study included lode zones at Wheal Pendarves, South Crofty and Rosevale tin mines. Fluid inclusion-containing microfractures are a common feature of the granites and typically show a preferred orientation over quite a large area. The close proximity of a dominant vein or fault controls their density and orientation. They are important pathways for fluids and provide a marker for palaeo-fluid flow. Overprinting provides a reliable representation of the evolution of the hydrothermal fluids in a vein system from early magmatic fluids to late-stage meteoric and basinal brine input. Measurement of microfracture orientation allows estimation of the regional stress regime during a specific hydrothermal event. Since micro- and macro-structures can generally be reliably correlated, these studies assist in modelling the detailed development of complex vein systems. Microfracture density is a good measure of palaeo-permeability, with implications for control of wallrock alteration. The determination of the location and density of microfractures can assist the mine geologist in identifying the location of potentially economic vein structures where macroscopic markers are absent

Aug 1, 1996

By W. J. Whiten, D. W. Grinsberg

Most cluster analysis techniques are not well suited to the analysis of engineering data as they have been designed for more qualitative data that tend to produce compact clusters. A clustering technique is described which develops and uses local cluster shapes to build clusters that are suitable for use in engineering applications. The technique is finding application in the analysis of many types of data, particularly where multiple trends and outlying points occur in multiple dimensions. Applications of particular interest are the calibration of on-stream analytical equipment and the analysis of data on plant performance. In both cases the multidimensional nature of the data renders manual analysis very difficult

Dec 1, 1991

By E R. Hassall

Discussiong the importance of minerals and mining, impacts on the environment and remediation, and the need to foster interest in science among young people.

Jan 8, 1997

By T. J. White, R. A. Farnfield

Early computerised blast monitoring equipment consisted of a digital version of the existing analogue machines with, perhaps, a few enhancements. Many additional facilities have since been developed to enable the efficient collection of high quality data. These developments are examined with reference to digital sampling, triggering systems, the storage of complete recordings and signal processing. Recent advances have been made in the use of blast monitoring systems that comprise multiple blast monitoring locations with centralised control and data collection. Software has been developed to help record blast parameters and assess environmental effects. Computer databases have many advantages over their paper counterparts. Data can be easily retrieved and processed. The scaled distances used in the prediction and control of peak particle velocities can be calculated rapidly when the data are obtained directly from a database. Since the whole vibration signal can now be recorded, signal processing can be used to provide information such as signal length, dominant frequency and response spectra.

Jan 4, 1993

By D. J. Esdale, D. F. Pridmore, F. W. Lindman, J. H. Coggon

Almost all the presently viable nickel reserves in the Yilgarn Block contain nickel in a sulphide phase. Both volcanic peridotite- associated (VPA) deposits and intrusive dunite-associated (IDA) deposits are characterized by massive, matrix and disseminated sulphides (typically, pyrrhotite, pentlandite, pyrite, chalcopyrite, magnetite and other spinels), though in the IDA deposits the volume of disseminated sulphides is far greater than that in the VPA deposits. Potentially all geophysical techniques have application in the direct detection of these deposits'gravity for the detection of the dense massive and matrix ore; magnetics for the detection of magnetite and pyrrhotite in the ores; electromagnetics for the detection of the massive and matrix ore; and induced polarization for the detection of disseminated and to some extent matrix and massive ore. In practice the application of geophysical techniques is limited to a varying extent by (1) the relatively small size of an economic accumulation of sulphides, particularly the VPA deposits, (2) the extreme depth of weathering and lack of outcrop on the Yilgarn Block and (3) the abundance of geological noise or anomalous responses caused by sources other than economic mineralization.

Jan 1, 1984

For the convenience of those who are unfamilar with thermodynamics, the following brief description and explanation is given of the thermodynamical terms and methods used in this book. It must, however, be strongly emphasized that the account given below is not an introduction to chemical thermodynamics; its sole purpose is to give the reader a rough understanding of the methods used in the earlier chapters. For further information, reference must be made to the standard textbooks on chemical thermodynamics by Glasstone.

Jan 1, 1953

By R. G. Jones

Chris Hinde talks us through his career from BSc in Mining Engineering to roles with Golder Associates, Schroder Securities, Mining Journal and SNL. He discusses the issues facing the mining industry.

May 1, 2015

By A. G. Royle

Sampling formulae for in-situ material, hard rock sampling and alluvial sampling are briefly discussed

May 1, 1991

Jan 1, 1984

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

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

Discussion of the paper presented at the Manchester Geological and Mining Society's general meeting held in Manchester, April 11th 1916, with Mr. Leonard R. Fletcher, President, in the chair, included questions asked and points for discussion raised by Bramall V., Paton J.D., Fletcher L.R., Siddall F.N., Stoker A. and Stone T., in particular on how to eliminate dust

Dec 1, 1916

By Blatchford A. S.

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.361-377, comprised written comments by Ashworth J. on the practicality of applying quenching materials to a dust cloud ahead of the explosion flame

Dec 1, 1916

By Haldane J. S.

Discussion of a paper presented at the Institution of Mining Engineers' general meeting held in London on 8th June 1916 included oral contributions by Louis H., Mowat D.M., Lupton A., Bailey T.H., Blackett W.C. and Gerrard J., and written contributions by Collis E.L., Carlow C. and Wilson W.B., with the author's oral and brief written responses

Dec 1, 1916