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By G. D. Nicholls

There have been very few attempts to isolate the various factors that contribute to the overall imprecision of geochemical analytical procedures, due in part to the difficulty of distinguishing between them. The technique of spark source mass spectrography permits a ready distinction between the contributions to overall precision from sampling error and instrumental and other errors. With conventional methods of sample preparation for this technique sampling difficulties are responsible for 80-90 per cent of the overall imprecision. Examination of the probable location of the major difficulties in sample preparation indicates that the preliminary stage of grinding, mixing and extraction of a first aliquot (about 1/100 of the original sample) is generally perfectly adequate. The difficulty lies in the subsequent stages of sample preparation. Dry mixing techniques are unlikely to give good precision if the sub-samples actually examined by the analytical technique are less than 10 mg in amount. Solution techniques are less prone to sampling difficulty. Fusion techniques, unless conducted with great care, can produce more difficulty than dry mixing. Sample preparation is critical to the success of many analytical procedures. Selection of appropriate sample preparation techniques requires just as much care as the selection of techniques for the actual analysis.

Dec 1, 1971

Discussion of the papers with a written contribution and authors' written replies.

Jan 1, 1947

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

By H. B. Bell, L. C. Smith

Measurements have been made of the activity of 'FeO' in 'Fe0'-Mn0-Ti02 melts at 1475 degrees C. The results obtained are discussed in terms of ideal mixing of titanates and in terms of a regular solution model. On the basis of the regular solution model activities of Ti02 and MnO in the Fe0-Mn0-Ti02 and Mn0-Ti02 systems have been derived. The data have been shown to be consistent with the liquidus lines in the phase systems. Examples are given of the application of the data to slag-metal equilibria, being used to derive slag-metal data between liquid iron and Fe0-Mn0-Ti02 slags

Dec 1, 1971

By S. Y. Ezz

Report of discussion at February, 1971, IMM general meeting (Chairman : M. J. Cahalan, President) of a paper published in Transactions/ Section C (Mineral Processing & Extractive Metallurgy), vol. 79, September, 1970, pp. C226-C233 with contributions by Wild R. and Astier J. on fluidised bed reduction of iron ore fines

Dec 1, 1971

By M. G. Fleming, F. Warner, R. W. Boswell, M. J. Cahalan

The annual dinner of the Institution was held at the Savoy Hotel, London W.C.2, on 22 April, 1971. The President, Mr. M. J. Cahalan, was in the Chair; members and guests numbered 320. The toasts of The Queen and Queen Elizabeth The Queen Mother, Prince Philip The Duke of Edinburgh, The Prince of Wales, and the other Members of the Royal Family were proposed and loyally honoured. R.W. Boswell proposed the toast of the Institution of Mining and Metallurgy, the president responded, Professor M.G. Fleming proposed the toast of the guests and Sir Frederick Warner replied

Dec 1, 1971

By T. A. A. Quarm

The concept of a continuous zinc smelting process which employs submerged combustion of coal char for both heating and reduction is described. An estimate of the results of smelting a marmatitic zinc concentrate indicates that both the operating and construction costs would be lower than those incurred in processes now in commercial operation. The results of smelting a complex zinc-copper concentrate are also estimated, but no simple commercial process exists with which they can be compared

Dec 1, 1971

By S. V. Shiraishi, H. B. Bell

Report of discussion at February, 1971, IMM general meeting (Chairman: M. J. Cahalan, President) of a paper published in Transactions/Section C (Mineral Processing & Extractive Metallurgy), vol. 79, June, 1970, pp. C120-C127, with a contribution by Wright P.A. on the miscibility gap

Dec 1, 1971

By C. P. Summerhayes, J. W. G. Gilbey, S. Henley, G. P. Glasby, J. J. T. Harvey, J. Larsson, O. Akiman, A. G. Brown

Abstracts are presented from six University of London, one University of Nottingham and one University of Durham PhD theses

Dec 1, 1971

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 W. R. Donaghue, R. L. Robinson, C. Scott

Whilst spontaneous combustion has never been considered a major problem in south Durham, certain collieries in the area have a history of heatings and precautions are essential. Three collieries are affected - Shotton, Vane Tempest and Seaham - and in the case of the last two, there are huge areas of high quality coal to work under conditions where spontaneous combustion is a real hazard. The seam being extracted has an immediate roof in goaf left by the incomplete extraction of a contiguous seam worked before the turn of the century. The presence of residual coal stocks and old roadways and cavities adds to the difficulty of preventing unwanted air movement. The main preventive measures adopted are the construction of airtight gateside packs and the use of sprayed surface coatings in the gate. Sampling systems and sampling points are described and, in particular the field of continuous monitoring from the surface is examined. The resulting possibility of a quantitative as well as qualitative assessment of the preventative measures required is discussed.

May 23, 1905

By E. L. Evans

The historical development of South Yorkshire mining is traced and note made of the liability to generate spontaneous combustion of some of the seams which have been worked. The liability factor is analysed firstly as an inherent property in the material of a coal seam, and secondly as a circumstance of a situation in which access is provided for the air necessary to sustain oxidation. The geological settings in which incidents of heatings have been known to occur is discussed and conditions favouring a natural pre-disposition to spontaneous oxidation exposed, particularly the effect of argillaceous material overlying the seam. An extensive strata-dynamic study follows to demonstrate the situations in which stray air currents tend to impinge on readily oxidizable material. Prevention techniques are indicated as the identification of strata-dynamic situations in which air access to broken coal is induced and thereafter th operational action to seal off the voids which have been opened up so as to exclude air from the broken coal. Measures to reduce the tendency for ventilating air to short circuit across waste voids, and to obviate deflection of air into packs are outlined. The importance of face and roadway design features is demonstrated and the consequences of practices inimical to good control of spontaneous combustion are related. Discussions on means of detection and also on the sealant materials available are included.

May 23, 1905

Discussion 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, of a paper published in Trans. Inst. Min. Engrs., 1916, vol. L., page 509, comprised a written contribution by O'Shea L.T.

Dec 1, 1916

By ed. comp., S. H. White, A. J. Naldrett, P. R. Simpson

Peter Simpson's introduction, Tony Naldrett's concluding remarks and discussion by Prof. White of D.M.A. Flight's report of the proceedings are presented from the conference held in Keyworth, UK, in April 1992

Apr 1, 1995

Two of the most important economies in coal-washing are in the actual washing of the coal and in a proper lay-out to reduce to a minimum the cost of labour for handling and washing. A guarantee is usually required for turning out a washed coal containing not more than 2% of free dirt and a resulting refuse with not more than 2% of free coal; any plant that gives results within such guarantees can he considered economical, provided that there are no other losses during the washing process. Various drainage arrangements and washery lay-outs are illustrated and discussed with respect to drainage, bunkers, sieves, settling tanks and conveyors and two further points considered: siding accommodation, which may become quite important with washeries of large capacity especially when the coal is brought in railway-wagons; and the irregularity with which the coal arrives. (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)

Dec 1, 1916

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

Jan 1, 1984

By L. R. Chimimba

"The Trojan nickel deposit occurs within a pile of ultramafic lavas subjected to a lower amphibolite grade of metamorphism. The lavas form part of the Upper Greenstones (Bulawayan Group) of the Mazoe greenstone belt. The nickel mineralization occurs as disseminated, massive and near-massive sulphides. The massive and near-massive ore occurs along the basal contact of the serpentinite units and is overlain by the more abundant disseminated ore, which occurs within the serpentinite. The main sulphide minerals are pyrrhotite. pentlandite and chalcopvrite. Minor amounts of millerite and pvrite are present. The Ni : Cu ratio in all three types of ore averages 15:1.The intercumulus nature of sulphides in the near-massive ore and similar textures occasionally seen in the disseminated ore indicates a magmatic origin of the mineralization. The basal position of the near-massive and massive ore suggests that the sul­ phides settled out under gravity during the emplacement and crystallization of a peridotitic magma. The deposit has been deformed and some of the primary massive ore has been remobilized into veins and breccias. The disseminated mineralization now occurs mainly as blebs of sulphides intergrown with silicate minerals or as stringers of sulphides between foliation planes in the serpentinite."

Jan 1, 1984

By J. A. Saunders, E. L. Rowan

It is now widely accepted that the metal-rich waters found in the oil wells are possible present-day analogues of the mineralising solutions that formed the Mississippi Valley-type (MVT) deposits throughout mid-continental USA and elsewhere. A study characterising the trace-metal content provides additional circumstantial evidence for a genetic link between sediment-hosted mineral deposits and basin brines: Ag, Co, Ni, As and Mo, detected in the scale, are locally present in accessory minerals in MVT deposits and the levels of Ag found in the wells support the conclusion that sedimentary sources for silver should be considered in evaluating the origin of Pb-Zn-Ag deposits in sedimentary terrains

Jun 12, 1905

By B. Denby

sintered ores, to be removed by a pneumatic,

Apr 1, 1995