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By H. L. Willett

Wrapping up the symposium, covers incidence of spontaneous combustion in British mines, assessment of liability to spontaneous combustion, precautions, rate of advance, starting a line of a coalface, local heatings at roadsides, burying packs, coal headings, retreating longwall, detection and sealant coatings.

May 23, 1905

Thermodynamical data of importance in connection with copper smelting have been reviewed and a collection of the most reliable information is presented in Tables XXV-XXVIII and Figs. 67 and 6 8 (folding plate). The data given in these figures and tables consists of (i) graphs and equations showing the variations in the temperature range 0-2000°C. of the standard free energies of formation of most of the oxides and sulphides met with in copper smelting (Table XXV and Fig. 67); (ii) equations showing the temperature variation of the free energy of formation of iron silicates (Table XXVI); (iii) graphs showing the variation with temperature in the range 1000°-1600°C. of the standard free energies of the principal reactions occurring in the smelter (Fig. 6 8 ); (iv) the standard heats of formation at 1200°C. of the main iron and copper compounds and gases reacting in the smelter (Table XXVII); (v) the standard heats of reaction at 1200°C. of a few of the reactions for which the free energy relationships were given in Fig. 6 8 (Table XXVIII). The data presented are discussed in more detail.

Jan 1, 1953

By G. B. Hooper, G. A. Ferguson

The technical capabilities and user-friendliness of the major computer-aided mining design software systems are reviewed. Recent experiences with three systems are outlined to indicate the practical problems that arise. The examples were: Microlynx software from Lynx Geosystems at the Great Dyke platinum mine in Zimbabwe; Lynx software from Lynx Geosystems at a copper mine in central Africa; and PC-MINE software from Gemcom Services at an open-pit gold project in Western Australia. Difficulties in the use of mining design software has led to an alternative approach. Falconbridge, Canada, has developed an integrated mine-planning system on a CAD platform that encompasses ore reserve estimation, stope design, development layout and survey control. Future directions of computer-aided mining design using this basis are discussed. A major advantage of using mainstream software packages, such as spreadsheets, databases and CAD programs, is that most engineers and geologists are experienced in handling such systems in the normal course of their work.

Jan 12, 1992

Discussion at the North of England Institute of Mining and Mechanical Engineers' general meeting held in Newcastle-upon-Tyne, 8th April 1916, on the paper published in Trans. I.Min.E., vol.LI, 1916, p.72-90, included written contributions on size and gauge standardisation by Lupton A., Peck W.R., Dean S., Mayer R.W. and Ashworth J., with the author's written response, and by Bulman H.F. and Brown M.

Dec 1, 1916

By Gibson J.

Further 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.72-84, included a written contribution by Parfitt I.C. and the author's written replies to this and previous discussion

Dec 1, 1916

By Ruddle R. W.

An outline account is given of the smelting of copper and the chemistry of the process. A table provides compositions of the more important minerals from which copper is won by smelting. Roasting is discussed as is smelting using reverberatory furnaces, blast furnaces and flash smelting. A brief discussion of converting covers the upright (Great Falls) converter and the horizontal (Peirce-Smith) converter.

Jan 1, 1953

By M J. Thomson, P T. Burgin

The economic growth of Hong Kong and adjacent territories in Southern China is, to a considerable extent, dependant on air transportation, but the present Kai Tak Airport is incapable of expansion to meet future needs. After years of study, agreement was reached to build a new airport on the island of Chek Lap Kok, some 34 km remote from Hong Kong, with an ultimate capacity of 87M passengers and 8.9 Ml of cargo per annum. Apart from the building of the airport and its associated infrastructure (including a new town), other similar massive construction works have been necessary in the form of land reclamation from the sea and existing outer lying islands. The construction of bridges, tunnels, railways and highways are also an integral part of the project. The paper provides a broad overview of the concepts of the scheme (called The Airport Core Programme) and highlights some of the major operations and equipment being used in the projects, whose cost at 1992 prices was reckoned to he Hong Kong (HR)$l63hn.

Jan 7, 1997

By M. W. Davies, P. N. Smith

The activity of MnO has been measured in the system CaF2-MnO at 1773 and 1873 K and in the system CaF2-CaO-MnO at 1773 K by the method of equilibration with platinum. Large positive deviations from ideal solution laws have been found, but these became less as the lime content rose. The loss of a volatile component made activity measurements impossible in the CaF2-AI203-MnO system, but the boundaries of a two-liquid region have been measured at 1773 K.

Dec 1, 1971

By J. Cech

Discussion is presented of a decision-making support method for the spacing of ore passes along a long vein orebody and the division of the orebody into convenient stopes for future mining operations. The method was tested on a Slovak siderite deposit and also on some hypothetical cases with the objective of obtaining more general results

Jun 18, 1905

By Jones R. G.

Dr Pat Foster, Senior Lecturer in Mining Engineering at the UK's Camborne School of Mines, talks to Rhiannon Garth Jones about mining safety around the world, education and the future of the industry

Feb 1, 2015

By J. E. Rouse, D. L. Buchanan

"During the emplacement of the Bushveld Complex in the Potgietersrus area magma reacted with the original floor rocks— Archaean granite or Malmani dolomite and overlying Penge handed ironstone or sedimentary rocks of the Pretoria Series. The complex sequence of sulphide-rich mafic rocks that formed along the contact is known as the Platreef. Associated with the sul­ phide mineralization are important concentrations of platinum-group metals, copper and nickel. Xenoliths of Malmani dolo­ mite have been incorporated into the Platreef and previous work has suggested that anhydrite is likely to have been present in the dolomite. The sedimentarv-derived sulphur thus introduced into the magma exercised an important control on the forma­ tion of the sulphides.Petrographic studies on the Platreef rocks from the Tweefontein area indicate that the original magma reacted with the banded ironstone to form iron-rich pyroxenites. In the Turfspruit area, to the south, the footwall rocks consist of sediments of the Timeball Hill Series. Original argillaceous rocks have been metamorphosed to cordierite-, corundum- and spinel-bearing hornfelses. Graphite was present in the contact zone in both the Tweefontein and Turfspruit areas. Anhydrite-bearing hornfels rocks are also present on Turfspruit.The Platreef rocks that overlie the corundum- and spinel-bearing hornfelses on Turfspruit are peridotitie, and pyroxenites are present in areas underlain by cordierite-bearing hornfels. The absence of orthopyroxene in the peridotite is probably indicative of low silica activity in the original magma. The pyroxenites have, however, undergone silica contamination from the underlying more siliceous cordierite hornfels.Carbon isotope studies indicate that the graphite in the Tweefontein and Turfspruit samples represents organic material orig­ inally associated with the footwall sediments. Sulphur isotope determinations on the anhydrite-bearing floor rocks indicate that this phase is clearly of sedimentary origin and was probably derived from an evaporitic unit within the carbonate sequence. This provides firm support for a model of ore genesis that involved the introduction of additional sulphur into the Bushveld magma. Isotope studies on sulphides associated with the banded ironstone and graphite indicate that these units were not the source of additional sulphur. Experimental studies predict, however, that a magma contaminated with iron- and carbon-rich material would have a high sulphur-carrying capacity. Where additional sulphur is available the magma would achieve saturation early in its crystallization history and precipitate an immiscible sulphide phase. Experimental work has also shown that sulphide precipi­ tation can be triggered by the introduction of salic material into a magma close to sulphur saturation. This mechanism probably played a role in the control of the sulphide mineralization in the Turfspruit area."

Jan 1, 1984

By A. L. W. Lips, B. P. J. Stevens, T. J. R. Bareley, E. Rothery, S. H. White

B.P.J. Stevens contributes a further response to the authors' earlier lengthy reply regarding their paper published in Trans.IMM B, vol.104, 1995, p.B1-B17, contending that despite the positive contribution clarifying their interpretations they perpetrate some misquotations, attempt to rewrite history and fail to understand the New South Wales Geological Survey's stratigraphic interpretation of the Broken Hill area. The paper's authors, in their further response, robustly defend their views, insisting that Stevens tends to misquote or take out of context what they have written and reiterating their findings that Zn is tectonically stacked above Pb at the north end of the orebody, that the written development of the stratigraphic interpretation is as they have stated, that shearing has attenuated or removed fold limbs in the Broken Hill block and that the 1:100 000 stratigraphic map reveals that magnetic anomalies are oblique to and truncated by the Geological Survey's interpreted stratigraphic boundaries

Jun 19, 1905

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

By Winmill T. F.

Among the various theories proposed to account for the spontaneous ignjtion of coal, one which has at times been very strongly held is that the initial heating is due to the oxidation of iron pyrites. From the results described in this paper, it is possible to calculate roughly the rate of spontaneous heating of a specimen of finely-divided pyrites, on the assumption that all the heat developed is used in raising the temperature of the pyrites, and that none is lost. It is clear that where finely-divided pyrites occurs in considerable proportion among coal, it may be the chief factor in originating combustion, but that pyrites can only be the cause of a heating when it is present in considerable proportion, and in a very finely-divided state

Dec 1, 1916

By B. Sonmez, B. Aksanl, S. Ersaym, I. F. Erkal, S. L. Ergun

The comminution circuit at the plant has experienced severe problems arising from a feed containing much larger amounts of clay and having a higher moisture content than expected. Three solutions were proposed: replacement of the crushing circuit by tooth roll-type crushers; using washing drums; and introducing primary autogenous/semi-autogenous millling instead of crushing. Computer simulations studied the effects of the first two solutions on the circuit capacity. Laboratory and industrial scale ball mill batch grinding tests were carried out. The parameters of a kinetic model were determined. The ball mill circuit was sampled and operating model parameters were calculated. The ability of batch grinding parameters to represent the operating conditions was studied. Tests failed to find acceptable model parameters, but parameters from an industrial size batch mill were found to be suitable for simulation studies. The simulations indicated that a continuous feed of -12 mm provided by tooth roll crushers would maintain the desired capacity. Increasing the feed size to -25 mm would reduce the capacity by 8-15%. The use of washing drums could also solve the capacity problem, but small fluctuations in water flow rates might result in problems of excess water in the grinding circuit.

Jan 4, 1993

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 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 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 N T. Byrom

This paper is essentially in two parts. It describes how risk assessment fits into the overall framework of the activities required to control risk effectively within an occupational health and safety (OH&S) management system. It then goes on to describe the assessment of an OH&S system by the process of auditing.

Jan 7, 1996

By E. H. W. Hornbrook, P. W. B. Friske

Paper presented at the 28th International Geological Congress, Washington DC, July 1989 (International geochemical mapping sessions). The objective of the programme is to establish and maintain a nationally consistent geochemical drainage database. Towards this end systematic surveys have been conducted since 1973. To date more than 200 surveys have been completed to the required standards, representing 180 000 sites and covering about 2 100 000 km2 throughout Canada

Jun 13, 1905