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Jan 1, 1984

By Evans E. C.

Discussion of the paper presented at the Manchester Geological and Mining Society' general meeting held in Manchester, March 14th , 1916, with Leonard R. Fletcher, President, in the Chair included contributions by Fletcher L.R., Paton J.D., Orchard A.J.A., Ross A., Gerrard J. and Stephenson H., with the author's responses

Dec 1, 1916

By I. R. Stevenson, J. G. Dunn, T. N. Smith, L. C. Mackey

An experimental flash reactor has been developed to simulate the operation of an industrial flash-smelter reaction shaft. Four concentrate materials of differing mineralogical compositions were characterised and then oxidised in the reaction shaft. The products were examined by chemical analysis to determine the extent of oxidation and by electron-probe microanalysis to determine the fate of individual particles. This programme of work enabled the influence of mineralogical composition and particle size on the extent of oxidation to be assessed

Jul 1, 1991

By A Misra

In pursuit of solving the development rate problem the coal industry has investigated various development systems. While all the systems may improve the development rate they may not necessarily he cost effective. This paper carries out an economic analysis by developing cost models for present and future development systems for retreating longwall faces with particular reference to Australian longwalls. A critical cost analysis of various development systems is presented by taking into consideration all the costs associated with development systems. The costs have been divided into equipment, face and panel services, belt and structure, wages, roof and rib support, ventilation, consumables, power and maintenance. The annualised cost of various equipment has been obtained on the basis of depreciation rates prescribed by the Australian Taxation Office.

Jan 11, 1996

By T. F. Bamber

The South Nottinghamshire Area has not been greatly troubled by spontaneous combustion until the last few years, during which the Blackshale Seam has been developed and exploited. The problem was first encountered at a colliery which was heavily preoccupied with a major reconstruction scheme, and with the sudden appearance of a completely new hazard both men and management had to adapt themselves very quickly to meet the situation. The paper contributed to the Symposium by the South Nottinghamshire Area illustrates the problems by reference to actual incidents, and shows how the lessons learned from them have been applied to the shaping of future policy on the avoidance and treatment of spontaneous combustion.

May 23, 1905

By I. Garba

The Bin Yauri deposit in the Zuru schist belt of northwestern Nigeria is a vein-type quartz-sulphide-carbonate gold mineralisation hosted by a brittle fault zone. The occurrence of the mineralisation in a contact zone of a Pan-African granitoid was believed to be sufficient evidence of deposition from magmatic fluids. However, studies may now indicate a metamorphic source for the mineralising fluids. A study of rare earth element geochemsitry was used to investigate the nature of the fluid-rock processes involved and identify the sources of the auriferous mineralising fluids.

Jan 12, 1992

By Ruddle R. W.

Magnetite occurs in the reverberatory furnaces, blast furnace and converter (a) as the result of its presence in the materials charged, and (b) as the result of oxidation of the FeS in the charge in the absence of sufficient SiO2 to slag the FeO as it is produced and thus prevent its subsequent further oxidation. Magnetite is reduced by FeS according to FeS+3Fe3O4=10FeO+SO2 and similar reactions. This reaction is markedly affected by temperature and does not proceed to any important extent below about 1200°C. To ensure comparative freedom from magnetite it is therefore necessary to raise the temperature of the furnace to the highest practicable figure and to use plenty of siliceous flux. Since the maximum operating temperature is likely to be limited by the resistance of the refractories to attack by the slag, investigation of the factors affecting this attack should be helpful. It is reasonable to suppose that the formation of magnetite might be minimized by ensuring intimate admixture of matte and slag during conversion so that silica is readily available for combination with ferrous oxide as the latter is formed. The literature gives no clue to the importance of this factor and some experimental work on this aspect might be fruitful

Jan 1, 1953

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 E. A. C. Chamberlain

New techniques for the continuous sampling and analysis of mine air are expected to replace traditional methods used for the early detection of spontaneous combustion. It has been established that the rate of evolution of carbon monoxide is the earliest indicator of incipient spontaneous combustion. Two methods of continuous monitoring of this gas are available and are now in use in the UK collieries. The first is the UNOR infra-red gas analyser, which is flameproof and may be used underground; the second is a system of tube bundles, which permits air to be drawn from any critical point in a colliery and analysed on the surface. Each system has its advantages and disadvantages but both provide the colliery manager with far more information on the condition of his pit than could previously be obtained by spot sampling and laboratory analysis. This paper describes the two systems presently in use and assesses likely future developments.

May 23, 1905

By A. Ludkin

The paper presents the history of the occurrence of spontaneous combustion in the north area, together with the associated problems. These are examined and a description is given of the methods used to combat the danger, including the use of modern scientific instrumentation. Detailed reference is made to the underground trials with pack injection and sealant coatings which were carried out at Seafield Colliery following the formation of a working group to assess the performance, in the same underground conditions, of (1) sandbagging, (2) pack injection, (3) surface coating. Based on these trials, an improved and more economical method of prevention has been established. There is, however, still scope for further improvement in techniques which would take into account the problems of gradient, transport, manpower and cost.

May 23, 1905

By M. D. Gibbs, T. N. Smith, B. Verbaan

When heated in the absence of oxygen, pyrite from refractory gold concentrates decomposes endothermically to pyrrhotite, releasing sulphur. The decomposition starts at the particle surface and progresses inwards, leaving an adhering layer of porous pyrrhotite. Use of the conventional shrinking-core model implicitly assumes a negligible partial pressure of sulphur in the bed, but this pressure is in fact at least equal to the equilibrium vapour pressure of sulphur over pyrite, constituting the principal control of the rate of decomposition. Further experiments showed a decrease in reaction rate as the conversion increased. Both phenomena are attributed to the persistence of non-isothermal conditions in the fluidised bed during pyrolysis, caused by the endothermic nature of the reaction and the relatively slow rates of heat transfer to particles and vapour removal from the bed. Equipment must be developed to maximise these two parameters

Jun 19, 1905

By R. F. Bell, Schultz

The paper briefly discusses the nature of spontaneous heating in mines in the Doncaster area, in the period immediately before 1967 and steps taken to prevent and treat such outbreaks. The changes that led to the increased rates of advice of Barnsley Seam faces since 1967 are listed and the effects of these increased rates on the frequency and location of spontaneous combustion are discussed. The change in methods of control required by the increased rate of advance of the faces and the changes in location of outbreaks are described. Some typical heating situations are evaluated. The methods described include the use of air sealants, water gels for filling of voids in wastes, the balancing of pressures across heating areas by pressure chambers, booster fans, and the resiting of air separation doors, and the sealing of air-ways by flooding. The authors discuss the influence of mine layouts on the risks of spontaneous combustion and advocate that future plans should be designed to limit the number of districts at risk when heatings occur.

May 23, 1905

The mineralogical composition of the ore was determined and the mineral phases with which nickel is associated were identified. The ore was prepared by grinding to -420 micrometres and classification into granulometric fractions. Prior to the main series of experiments the effect of agitation rate on nickel recovery was investigated. The influence of sulphuric acid concentration, temperature and particle size on the kinetics of nickel extraction was then studied, both quantitatively and qualitatively, over fixed value intervals. Application of the initial rate method enabled determination both of the order of reaction with respect to sulphuric acid concentration and the activation energy for the dissolution of nickel. The results indicate that a physical mechanism can be ruled out as the rate-determining step in the extraction of nickel from the ore and that a chemical mechanism is more likely

Dec 1, 1991

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

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

"Prior to the publication of the General Report of the Miners' Phthisis Prevention Committee of South Africa in 1916 little attention was paid to the dust hazard and the necessity for its suppression in the underground workings of the Broken Hill mines. Such precautions as were observed for the elimination of dust were related rather to the prevention of lead poisoning, which, in the early days of Broken Hill when large tonnages of lead carbonate ore were being won, was rather prevalent. Ventilation and hygiene followed the general practice in this and most foreign countries.This paper covers incidence and action since 1918, considering medical aspects and operating aspects. "

Jan 1, 1947

By D. F. Ball, P. R. Dawson, J. T. Fitton

Report of discussion at December, 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, September, 1970, pp. C189-96, plus the authors' replies. Contributors included Cohen E., Hope B., Wasse D.G., Shakespeare A.G., Burwood D.S., Jones H.A., Dartnell J., Carter G.C., Henderson T.A., Relf G. and Clark S.W.

Dec 1, 1971

By D. R. Wardrop, P. J. Rowsell, M. D. Waller

D.R. Wardrop agrees that artificial intelligence can contribute significantly to a reduction in both unit and overall well drilling costs but argues for human input to be allowed to overcome the differences encountered on striking the reservoir

Aug 1, 1995

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 M. L. Schmulian

"The Windarra nickel deposits display many of the characteristics that typify Archaean volcanic peridotite-associated nickel sulphide ores of Western Australia. The Fe-Ni-Cu sulphide mineralization, which comprises dominantly disseminated sulphides, occurs at the base of a differentiated ultramafic volcanic pile grading upwards from massive meta-peridotitic flows to thin, locally spinifex-textured meta-picritic units. The entire mafic-ultramafic belt has been subjected to mid-amphibolite- facies metamorphism. The ore-bearing ultramafic is immediately underlain by dominantly sulphide-facies banded iron formation (BIF), which commonly contains nickel sulphides adjacent to its contact with mineralized ultramafic. BIF-hosted ores are formed both by physical remobilization of ultramafic-hosted sulphides and by migration of Ni and Cu into pre-existing iron sulphides.At Mt. Windarra the mineralization comprises eight steeply dipping, steeply plunging elongate oreshoots, which display a marked parallelism with major and minor fold structures in the underlying BIF. Seven of the shoots occur at or close to the base of the ultramafic pile, and are hosted by at least three overlapping flows. The zone of overlap occurs at the northern end of each flow, where picritic ultramafic, representing a dominantly liquid portion of the flow, occupies the basal contact. A gross south- north ultramafic flow direction is inferred. The eighth shoot occurs in a stratigraphically higher position within the ultramafic sequence.At South Windarra at least two overlapping mineralized flows occupy the basal contact, the ore zone having a strike extent three to four times its downdip extent. There is no obvious structural control to the mineralization."

Jan 1, 1984