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By Garforth W.

The chairman announced the new government duties of the out-going President, Sir Thomas Holland, and the formation of a new standing committee on mining to advise the Advisory Council for Scientific and Industrial Research on suitable projects for grants. Some of the potential lines for investigation into the best methods of winning and presenting coal in the best commercial condition include wasteful practices in operating steam boilers, national loss due to neglecting recovery of coal by-products, and the leaving of large areas of coal for fear of spontaneous combustion or as boundary pillars and support

Dec 1, 1916

By M. J. Matos, W. Patruk

The correct version of Equation 1 is represented and Tables 3 and 6 are revised to consider all size fractions, including those coarser than 300 micrometres, in calculating the total liberation from King's fractional liberation

Jun 18, 1905

By Fearnside W. G.

Further 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., 1915, vol. L, p. 573 and discussion vol. L., p. 109 and 608, comprised a brief written contribution by Faulds A.

Dec 1, 1916

By Hickling G.

Discussion at the Manchester Geological and Mining Society's general meeting held in Manchester, February 8th 1916, with Mr. Leonard R. Fletcher, President, in the chair, of papers previously published in Trans. Inst. Min. Engrs.,1915, vol. L, p.322 and p.328. Included are a written contribution by Ollerenshaw W. and oral discussion by the author, Gerrard J., Paton J.D., Smith S.A., Stephenson H., Dixon H.O., Pickup W., Fletcher L.R. and Atherton H.S.

Dec 1, 1916

By M. C. Amiri

The plant produces 130 kg slag per tonne of crude steel, to add to the basic oxygen steel-making converter slag stockpile of around 2 500 000 t. The slags contain 1.81% V2O5, which can be rendered water-soluble by salt roasting with NaCl and an alkali such as Na2CO3. Preliminary tests gave less than 3% V recovery from slag under optimum roasting conditions when NaCl, NaCO3 or Na2SO4 was used, but showed that sodium phosphate could make all the V water-soluble when roasted with slag in a ratio of 3:1 at 1 100-1 200 degrees C. Almost complete leaching was obtained within 2 h with water at boiling point. Sodium vanadate was precipitated by acidifying the leach liquor with HCl to a pH of about 2.2

Jun 21, 1905

By A. Policard

The question, of the pathogenesis of pneumokoniosis is very important not only from the social and economic points of view but also from the purely biological. The study of the pathogenesis of the disease leads to fascinating problems of cytology and cytochemistry. Two problems present themselves for examination from an analytical and critical point of view: 1. The first reactions of the alveolar walls to inhaled dusts. 2. The precise nature of the action of mineral dusts.

Jan 1, 1947

By G. Mellgren, O. Mellgren

The conductivity of a solution is often used industrially to control the salt concentrations of reacting systems, normally using electrodes made of glass fitted with platinised platinum electrodes. When a standard platinum conductivity electrode was used to control the acid fed to the leaching circuit for an ilmenite flotation concentrate at Titania, Norway, a deposit of calcium sulphate (containing some calcium phosphate) covered both the platinum electrode and the external glass fitting, rendering the electrode inefficient in the course of a few minutes. A new electrode consisting of a casing, two measuring tubes and an electrode stem is described and illustrated. A significant advantage of its design is that the useful range of conductivity measurement can be adjusted by adjusting the concentration of the electrolyte in the electrode. It has been in use at Titania for about four years with an electrolyte consisting of 0-1 n HCI. It is robust and demands little maintenance.

Dec 1, 1971

By Ruddle R. W.

Although copper has been smelted for many years, relatively small attempt has been made in the past to examine the fundamental physical chemistry of the processes involved. Therefore, technological developments apart, slow progress has been made with the development of improved or new principles of smelting. The methods at present in use in the majority of the world’s smelters are essentially those employed at the beginning of the present century; it is significant that many of the textbooks on copper smelting, written some 50 years ago, are still regarded as standard works. The book is divided into seven chapters. In the first the fundamentals of modern smelting processes are briefly outlined for easy understanding of the subsequent sections, while the next two chapters are confined to the more theoretical aspects of the constitution of mattes and slags. Some problems of considerable practical importance are discussed in the remaining four chapters; these are (1) magnetite formation, (2) copper losses during smelting, (3) the recovery of sulphur from the smokes produced during smelting, and (4) the elimination of impurities. A collection of thermodynamic data relevant to copper pyrometallurgy is presented in an appendix, and, for the convenience of readers not well acquainted with thermodynamics, a brief explanation of the thermodynamic terms and methods employed is given in a second appendix

Jan 1, 1953

By D. H. Watkinson

Paper presented at the IAGOD international symposium on mineralisation related to mafic and ultramafic rocks held in Orleans, France, 1-3 September 1993. Part of the contact of the 4b orebody with the enclosing Murray granite is characterised by the presence of recrystallised and biotitic Sudbury Breccia; in places the contact is faulted and sheared. In other areas of the contact partly silicified granite contains disseminated chalcopyrite and quartz-chalcopyrite veins with other minor minerals. Both ore and veins contain platinum group minerals (PGM); predominant PGM are michenerite, kotulskite, merenskyite and sperrylite with Au, galena and Bi-tellurides. At some silicified-granite contacts Mn-rich garnets, some containing inclusions of PGM and quartz, are associated with biotite + epidote + stilpnomelane + quartz. PGM and Au also occur within Cl-rich biotite and ferropyrosmalite in massive sulphide and in siliceous ore. Quartz, chalcopyrite and feldspar in the contact rocks and in veins contain abundant, highly saline fluid inclusions. Studies showed that the fluids were trapped at intermediate temperatures. The 4b orebody is surrounded by a sheath of brecciated granite but is close to the Contact Sublayer. During and after emplacement of sulphide magma, saline formational fluid that was resident in the breccia interacted with hot massive sulphides in and near the Sublayer and remobilised Cu, Au and PGE. This fluid reacted with cooler rocks and ore in footwall fractures, enriching the 4b protore and producing the adjacent Cu- and PGE-enriched quartz veins. Exploration for Cu and PGE enrichment in footwall rocks of the Sudbury South Range is warranted not only in zones of magmatic ore in the Contact Sublayer but also in fractures and permeable units within Sudbury Breccia

Jun 16, 1905

By C. A. Pickles

Mixtures of silver chloride and copper chloride are produced during gold refining by the Miller process. A study was carried out into the reduction with iron of a synthetic Miller chloride containing 13.64 mass% Ag and 2.42 mass% Cu. The effects of smelting temperature and time and of additions of iron and borax were investigated. The results were interpreted in terms of metal recovery and quality. Temperature did not have a significant effect on metal recovery above the melting point of the metal product. Borax additions reduced vapour losses and improved metal recovery. With excess iron it was possible to achieve silver recoveries of about 100% and copper recoveries of about 70%. The metal product contained on average 76.1 mass% Ag, 7.5 mass% Cu and 12.8 mass% Fe.

Jan 4, 1993

By F. G. Bell, S. E. T. Bullock

The investigation was undertaken as part of the environmental management programme that must be implemented on mine closure. It involved sampling and analysis of water from boreholes, the tin mine workings, trenches and pits as well as soil and dumps. Both ground- and surface water in the immediate vicinity of the mine was found to have been affected to varying degrees, mainly due to acid drainage from the pyrite dumps. Metal ions and toxic salts are taken into solution with increased acidity and precipitated in the soil when the pH rises again; there are concentrations of metal ions in the soils around the main dumps, but these do not seem to pose a major threat in a regional context. The low groundwater gradients, together with the dyke system in the vicinity of the main dumps and the impermeable nature of the Boschoffsberg rocks, make it unlikely that affected groundwater will migrate further than 1 000 m to the north and north-east. Nonetheless, it has been decided to remove the pyrite dumps

Dec 1, 1995

By V. Distler, E. F. Stumpfl

Paper presented at the IAGOD international symposium on mineralisation related to mafic and ultramafic rocks held in Orleans, France, 1-3 September 1993. The massif contains large chromite bodies of "Alpine-type", ophiolitic affinity. Orebodies reach thicknesses of 150 m and sizes of more than 150 000 000 t chromite ore with average grades of 55-60 wt% Cr2O3. Chromites in the Main ore field are low-Al, high-Cr spinels which exhibit some variation in their Mg-Fe distribution. This differs markedly from high-Al spinels in peridotite host rocks and in narrow chromite pods which occur in the western and northern parts of the massif. Chromites carry silicate inclusions, often hydrous silicates such as amphibole. Chromites in massive chromitites contain micron size inclusions of platinum group minerals (PGM). Composite grains containing two PGM and, occasionally, a hydrous silicate are common. Os-Ir alloys rimmed by PGM sulpharsenides occur in narrow serpentine veinlets that cut chromite and are evidence for the reconcentration of PGE concomitant with introduction of As, probably during serpentinisation. Whole-rock PGE contents are highest in massive chromitites of Diamond Pearl mine (totals of 500 ppb). Chondrite-normalised PGE patterns of chromitites show negative slopes which are typical for ophiolitic, podiform chromitites in mantle sequences. The PGE patterns of host rocks are flat and rather depleted compared with those of chondrites and chromitites. Petrological data from unaltered host peridotites suggest a high temperature overprint leading to sub-solidus re-equilibration of olivine and spinel and to the growth of pargasitic and edenitic amphiboles

Jun 16, 1905

By D. A. White

A simple model for hydrocyclone classification based on the crowding theory first put forward by Fahlstrom is presented. This is a mechanistic theory that postulates that the behaviour of a hydrocyclone is the result of an ordered process that is independent of its dimensions. The main variables that describe the process are the fractions of feed solids and water that are ejected from the underflow. A simple model is developed from basic properties of the classification process and is compared with theory. Agreement is good but improves when the cyclone has a high solids content

Dec 1, 1991

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 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 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 Gibson J.

The writer hopes to prove that the economical tram is of even greater importance than, say, the economical engine, and as no difficult and involved calculations are required, and all the governing facts are simple and well known, the former is more easily attainable than the latter. In the first section of this paper the factors that determine the size and the construction of the tram are examined; whilst in the second section the road on which it runs is dealt with

Dec 1, 1916

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 K. M. Kinealy, A. R. Ramsden, D. H. French

A negative correlation exists between sphalerite composition and gold content when gold is transported as Au(HS)2(-); however, there are spatial and temporal differences within a single deposit. A previous model for the formation of volcanogenic massive-sulphide deposits within thermally intensifying and waning hydrothermal sytems in much the same way as is observed around modern sea-floor vents is supported. The results also emphasise that recognition of the mechanisms of gold transport in ancient deposits depends critically on an understanding of their mineralogy and stratigraphy

Jan 1, 1991