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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 M. Thompson, B. Coles, M. Hale

The use in regional geochemical reconnaissance of replicate analysis of natural coatings of iron and manganese oxides on the surface of pebbles in stream sediment is described. Pebble coatings were selectively analysed for their relative contents of absorbed trace elements by ablating a small quantity of the coating with a laser beam and sweeping the aerosol obtained into an inductively coupled plasma atomic emission spectrometer. Using this procedure, a geochemical survey in northwest Wales revealed anomalous concentrations of Cu, Mo, As, Zn, Cd, Pb and Co in the pebble coatings of streams draining the mineralised Coed-y-Brenin diorite and the Dolgellau gold belt.

Jan 4, 1992

By G. I. D. Roach

The leaching, with hydrochloric, sulphuric and perchloric acids, of suspensions and massive specimens of different haematite and goethite samples has been studied. Both accelerating and constant types of leaching curves have been observed. It is concluded that the grain to particle size ratio of the oxide being leached determines which type of leaching curve is obtained, particles containing a large number of individual grains producing the accelerating type of curve

Dec 1, 1971

By Groom P.

Discussion of the paper presented at the Midland Institute of Mining, Civil, and Mechanical Engineers' general meeting held in Leeds, March 21st, 1916, with T. Beach, vice-president, in the chair included contributions by Beach T., Fearnsides W.G., Lloyd W.D., Gill J. and Nadin R.

Dec 1, 1916

By G. R. Chaudhury

Many base metals, such as copper, lead and zinc, are commercially extracted by thermal processing of sulphide concentrates. However, owing to the depletion of high grade sulphide ore reserves and to environmental legislation, efforts have been in progress for some years to develop methods for the extraction of metals from lower-grade oxide ores and secondary resources, and there are now examples of commercial-scale operations.

Dec 1, 1995

By M. Schwartz

Hosting copper, gold, oil and liquefied natural gas, the country is an interesting target for miners. However, remote locations in inhospitable, unusual and difficult terrain cause problems. The government has worked to create a Sovereign Wealth Fund to manage government surpluses from minerals and energy but PNG scores very low among many criteria, including land dispute resolution, as revealed by the 2014 Canadian Fraser Institute in its survey of senior mining personnel.

May 1, 2015

Further discussion at the Mniing Institute of Scotland's annual general meeting held in Glasgow, 8th April 1916, of the paper published in Trans. I.Min.E. vol li, 1916, p.169-186 with discussion p.187-188, included oral and written contributions by McLaren R. and Waddell H.

Dec 1, 1916

By C Selcuk

This item considers the work of the CleanMine consortium on the removal of hard scale from valves via the combined use of controlled acoustic cavitation with guided wave propagation.

Jun 1, 2015

By Fearnsides W. G.

The map shows the sites of collieries and important boreholes in the district, with approximate underground contours of the pre-Permian surface of the Coal-Measures and of the Barnsley Bed

Dec 1, 1916

By Stainier X.

The connexion between the Kent and the Continental coalfields on the one hand and the western British coalfields on the other has been for many years a controversial subject between geologists. These coalfields were once considered as detached portions of a former extensive sheet of Carboniferous deposits, but some geologists seem now to incline to the view that they were never connected. The writer hopes to show that the problem is one of the most difficult of geological investigations; that we are still far from a perfect solution; and that both of the extreme theories must be set aside. The physiography of NW Europe during the Carboniferous, with its various generations of earlier folds, is outlined and the features of the Lower and Upper Carboniferous anticlines and synclines discussed, followed by consideration of the denudation of the coalfields and local descriptions of the Malvernian range and Usk anticline, the Pennine chain, the Shropshire coalfield and the Kent coalfield. An attempt is made to trace the transverse Midland anticlines southwards and to deal with the intervening syncline: for example, if the dissymmetrical profile of the Pennine Chain holds good at its southern end then the syncline west of the chain must be deeper than the syncline east of it (the Kent syncline), and in this syncline the deepest part must be at its south-eastern corner, and therefore south of the diagonal ridge. T here is some actual evidence of the existence of Coal-Measures in this syncline, as the results of the Batsford and Burford borings prove. The hypothetical character of most of the conclusions will prove, beyond any doubt, how fa r geologists still are from a perfect settlement of this problem, and how much this settlement is dependent on the more or less advanced state of knowledge regarding all the geological features of these coalfields and of the surrounding country

Dec 1, 1916

By B. H. Smith

"Most of the discoveries of nickel sulphide deposits in Western Australia have followed the search for gossans. The chances of further discoveries depend on improving our understanding of the cover of strongly leached and transported materials that obscure approximately 85% of the area of the Yilgarn Block that has nickel sulphide mineralization potential. The lateritic profiles that are observed on the Yilgarn Block today were formed over a period of more than 100 m.y. of warm and humid climates. This lateritized land surface has been preserved by induration during subsequent arid climates as well as by the structural stability of the Yilgarn Block.In geochemical surveys of lateritied terrain samples have to be taken from at least the saprolite zone usually by drilling so that confident predictions can be made of the significance of analytical data. Account must be taken of the mineralogy of samples, as well as the nature of the horizon of a laterite profile that is being sampled, owing to the concentrating effects on trace elements of Fe and Mn oxides.Multivariate techniques have been applied successfully to analytical data in gossan recognition when textural evidence is ambiguous. Pathfinder geochemistry has also been used in gossan recognition and the most significant recent advance has come from studies of platinum group metals in nickel sulphides and their dispersion during weathering."

Jan 1, 1984

By G. Richards

Following on from the article in Materials World February 2015 (Asset 997) this article is the second half of a special focus on graphite. It looks at graphite's market prospects over the next few years. Natural graphite is used in refractories, which accounts for ca. 20% of global demand and is forecast to grow by 2-4%/a to 2020, while the largest growth in demand (increases of 10-15%/a) is estimated to come from its application in anodes for lithium-ion batteries, especially those in hybrid electric vehicles. High-grade natural graphite deposits that are either coming back on stream or are in the pipeline are discussed including Woxna mine in Sweden, Bissett Creek project in Ontario, Canada, Balama mine in Mozambique and Lac Knife project in Quebec, Canada

Mar 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 Le Thac Xinh, van Chu Nguyen

In northern Vietnam Ni-Cu sulphide deposits associated with ultramafic rocks are located in several continental rift zones of Permo-Triassic age. In recent years a number of ultramafic bodies have also been discovered in southern Vietnam, but detailed work on sulphide occurrences within these bodies has still to be undertaken. A brief description is given of some N i-C u sulphide deposits that are located in the northern part of the country. Of the depos­ its that have been examined in any detail, those in the Takhoa region are of the greatest economic interest. Ni and Ni-Cu sulphide bodies have, however, also been found in association with the ultramafic rocks.

Jan 1, 1984

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 T. D. Jones

Describes the facilities in South Wales for routine control and research work on all the various aspects of the dust problem. Considers mining and medical research, inspection and control, education, and plans for the future.

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 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

By B. Denby

sintered ores, to be removed by a pneumatic,

Apr 1, 1995