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By D. R. Wardrop, G. Walton

Paper presented at the UK minerals industry conference held in Leeds, UK, 3-5 April 1995. A description is given of the approach that has been taken to the design of the 550 000 000 t superquarry with a planned life of 60 years that is proposed for development. The quarry has been designed to replicate a corrie and a sea loch and will include excavated slopes more than 570 m high. The main geological and physical controls on the layout and the choice of development method are outlined. The operation phasing is presented and the geotechnical constraints on slope design and the feasibility of alternative quarry limits are discussed. Environmental considerations have been dominant in planning and the quarry has been specifically designed for closure

Jul 1, 1996

By J. M. Jimenez, G. D. Schena, A. J. Cazorla

A full-scale Deister column was operated in parallel with the conventional cleaning bank of cells and a pilot Jameson cell in parallel with the conventional rougher cells. Flotation column performance was appreciably enhanced by use of an improved washing system and an internal launder. The performance of the rougher bank of cells, Jameson cells, cleaner cell bank and column were described by simple linear functions. These allowed calculation of overall circuit recoveries and evaluation of alternative circuits. An evaluation procedure based on a financial criterion is demonstrated with a simplified example, illustrating how revenues and operating margins are often of more concern than concentrate grade and recovery

Jun 18, 1905

By D. M. Evans, D. L. Buchanan

Paper presented at the IAGOD international symposium on mineralisation related to mafic and ultramafic rocks, held in Orleans, France, 1-3 September 1993. The Zinca area was chosen as a suitable location for an investigation of the weathering and secondary dispersion of platinum group metals from the Zone. It was concluded that platinum is immobile while within weathered rock, its mineral phases tending to alter from primary sulphides and tellurides to secondary Pt-Fe alloys. Palladium is variably mobile in weathered rock. In stream sediments Pt occurs mainly as small, dense, discrete particles, giving rise to a nugget effect, whereas Pd probably occurs as much finer particles or chemically adsorbed on to a suitable substrate. Pt shows a rapid decrease in sediments downstream from mineralisation, whereas Pd has a much slower downstream decay

Apr 1, 1994

By T. From

The organisation's mission is to promote research and technological development in processes relevant to the minerals industry by providing expertise, developing and managing jointly funded projects, undertaking commissions and education and establishing and maintaining research and development networks. It was responsible for the administration of the Mining Technology 2000 national programme to reduce production costs per metallic unit by 50% over 5-8 years, which involved 120 projects in all. Technical areas included ore characterisation/delineation and mine planning, rock fragmentation, rock mechanics, maintenance, energy and ventilation, automation and information systems, cut and fill, bulk mining methods, drifting and production-face development. Other projects have been the Ore Geology Related to Prospecting (PIM) programme to raise the standard of ore geology research in Sweden and promote exploration for volcanogenic massive sulphides in three key regions, and a joint research project on ventilation control according to requirement, including development of fan and gas monitoring systems and an improved, adjustable and intelligent fan

Jun 17, 1905

By T R. Marrero, J W. Wilson

This paper presents costs for a coal log pipeline that can transport coal over distances from 50 km to 1500 km. The coal log pipeline (CLP) concept is a new technology in w hich coal is compacted into water impermeable circular cylinders that can be suspended in water flowing through an underground pipe. CLP includes processes to prepare the run-of-mine coal for compaction, the injection of coal logs into a pressurised water-lilled pipeline, the conveyance of the coal through a pipe including special pumping stations, and the treatment of the coal logs and water at the pipeline outlet. An 8 inch (203 mm) pipeline can transport more than 2 Ml of coal per year. CLP components have been extensively tested in bench-scale facilities where these tests have included start up/shutdown steady state flow behaviour, end of pipeline treatment of water and coal log handling, water hammer effects, abrasion of logs and pipeline, coal log manufacture, and other engineering operations. Several sites are being considered in the United States (US) for the first commercial demonstration that will probably take place in 1998. The cost calculations are based on realistic values for all the components of a CLP. including a return on investment. For pipelines of different diameter, values for coal transportation are presented in terms of $(USVtonne as a function of distance.

Jan 10, 1996

By Y. Ichihara, H. Matsumoto, K. Itakura, H. Eguchi, G. Deguchi, K. Sato

Mechanical data from a rockbolt drilling machine, such as torque, thrust, revolution and stroke, are useful for understanding the geological and geomechanical conditions around roadways and hence selecting the optimum bolt type and density. Laboratory experiments showed that the level of torque or thrust reflects differences in rock type, with separation of strata and cracks appearing as a specific pattern. Algorithms of neural networks based on adaptive resonance theory and back-propagation were used to extract the pattern and estimate the location of discontinuities. For field testing in an underground coal mine, a prototype data acquisition system was attached to a portable drilling machine. Several sets of logging data from one locality were combined to construct a two-dimensional model of the strata, from which the slope angles of discontinuity faces could be estimated

Jun 19, 1905

By A. S. W. Kurny, M. Z. Huq

Bangladesh ilmenite is partially altered, containing pseudorutile, rutile and haematite as well as the predominant ilmenite phase. A typical analysis is 39.45% TiO2, 24.19% FeO and 33.0% Fe2O3. Reduction of the ilmenite by charcoal was found to involve two major reactions: conversion of pseudorutile into ilmenite and rutile, and change of ilmenite into metallic iron and rutile. The first, which was much the faster reaction, was responsible for an initial increase in ilmenite content with reduction time at lower temperatures. Apart from these two major reactions, rutile was reduced to lower oxides at 1 100 degrees C with a consequent decrease in its XRD peak height

Jun 19, 1905

By E. Niehuis, J. Y. Kim, H. G. Cramer, S. L. Chryssoulis, K. G. Stowe, C. Bendel

TOF-SIMS was used to detect, identify from parent molecular ions and determine the relative concentrations of collectors sorbed on the surface of mineral particles in concentrate and tailings samples from three Canadian concentrators. In the Kidd Creek Zn circuit, sphalerite lost to tailings carried on average a quarter of the amount of isobutyl xanthate present on that recovered to Zn concentrate; amyl xanthate, which is not reported as added to the circuit, was also detected on floated sphalerite and pyrite. At Brunswick, sphalerite particles lost to the scavenger tailings had ten times less amyl xanthate and isobutyl xanthate than those recovered to the Zn final concentrate, while both xanthates were detected on sphalerite floated to the Cu-Pb cleaner circuit. At Matagami, significantly more isopropyl xanthate and isopropyl dithiophosphate were detected on sphalerite recovered to the final Zn concentrate than on that lost to the Zn rougher tailings

Dec 1, 1995

Jan 1, 1947

By W. Doherty, P. C. Lightfoot, V. A. Fedorenko, N. S. Gorbachev, V. I. Kunilov, A. J. Naldrett, Z. Johan

Paper presented at the conference Economic geology in Europe and beyond II, models for mineral deposits in sedimentary basins, held in Keyworth, UK, 13-14 April 1994. A model is presented which regards the Lower Talnakh- and Talnakh-type intrusions as part of the plumbing system for the overlying lavas. As magma ascended along the Noril'sk-Kharayelakh fault it was forced to spread out within sedimentary strata immediately beneath the obstruction of the accumulated volcanic sequence. Here it was severely depleted in chalcophile elements by sulphides, which were then trapped by their high density and remained behind in the main arteries to form the central, elongated zone of maximum thickness. Subsequent magma also lost Ni, Cu and PGE to the sulphides as it flowed through. The Lower Talnakh-type intrusions represent part of the plumbing system that became blocked at an early stage, before the influx of much mokulaevsky-type magma rich in chalcophile elements. The model accounts for the high metal content of the ores in comparison with the size of their associated intrusions, the extensive metamorphic aureoles, the chalcophile depletion of some overlying volcanic suites, the presence of the ore in near-surface intrusions rather than deep magma chambers, and the sulphur isotopic composition of the ore

Apr 1, 1995

By A. Sutton-Pratt

The African continent has been the most prolific producer of gold since mining began. Although most of this gold has come from South Africa, other countries have also been important contributors in the past. There is currently little production outside South Africa, Ghana and Zimbabwe, but the gradual globalisation of the industry over the past decade has resulted in growing interest in the region which bodes well for its future development. An outline is given of prospects and activity (or lack of it) in South Africa, Lesotho, Swaziland, Zimbabwe, Mozambique, Madagascar, Botswana, Namibia, Zaire, Tanzania, Kenya, Uganda, Rwanda, Burundi, Zambia, Malawi, Angola, Congo, Central African Republic, Gabon, Equatorial Guinea, Ethiopia, Eritrea, Djibouti, Somalia, Sudan, Chad, Libya, Tunisia, Egypt, Algeria, Morocco, Ghana, Ivory Coast, Liberia, Sierra Leone, Guinea, Senegal, Guinea-Bissau, Gambia, Mauritania, Mali, Burkina Faso, Togo, Benin, Niger, Nigeria and Cameroun

Apr 1, 1996

By P. H. Carr, G. G. Marino, K. A. Patel

Extensions to a correctional institution at Wabash Valley, Indiana, required development over abandoned coal-mine workings, at 90 m depth, where subsidence was possible at surface. Backfilling of the flooded mine in critical areas was determined to be the most cost-effective method of limiting the risk of damage to the buildings. Containment grout was first placed in selected entries and cross-cuts of each mine area; the remaining volume was then filled with a readily flowing infill grout. Where a high proportion of an area was taken up by rubble, calcium lignosulphonate was used as a retarder and plasticiser to increase penetration. Grout movement was monitored from adjacent boreholes with an electrical resistivity probe during grouting, while after the work was finished core samples were obtained from verification holes drilled in the backfilled areas

Jun 19, 1905

By J. Temporal

An introduction to the conference material in this issue is given together with the issue contents list, closing remarks by its chairman Dr. J. Temporal, the list of contributors and their companies, and the information that the 26th Sir Julius Wernher memorial lecture had had to be presented by the lecturer's wife, M. Biggart, in his absence due to site problems on the Storebaelt project

Jun 16, 1905

By T. Bennett

Geothermal energy has the potential to provide 20% of the UK's annual average electricity generation capacity requirement. This article discusses the costs and potential benefits.

Jun 1, 2015

By Winmill T. F.

(Paper presented at the Institution of Mining Engineers' general meeting held in London on 8th June 1916.) The conclusions reached in this paper may be summarized briefly as follows: (1) The method of estimating moisture in coal by determining the loss in weight of a sample heated to 105°-110° Cent, in an air-bath for an hour is untrustworthy, the results so obtained being too low. (2) Dried coal has a very considerable power of absorbing moisture, and a sample, after being dried, must be protected instantly if it is to remain free from moisture. (3) A fairly accurate estimation may be made by heating the coal in a current of dry air at 105° to 110° Cent., and collecting the moisture evolved. (4) In cases in which it is proposed to use the dried coal for any further experiments, the drying must be done in the absence of oxygen, and this can be done simply and quickly by the vacuum method now described

Dec 1, 1916

By R. Sweennen, A. Vervoort, J. Caers

A case study is presented of the mechanical behaviour of fractures in the Westphalian A and B siliciclastic succession of mud-, silt- and sandstones with intercalating coal layers in the Campine basin of northeast Belgium. Mining ceased in the area in 1992 and a pilot well was drilled to assess the feasibility of methane extraction by hydraulic fracturing. Work was carried out to study the influence of types of cement fill in fractures on the shear behaviour of the rocks by comparison with that of the coal seams. X-ray computerised tomography was used for visual appraisal and selection of jointed rocks before destructive shear testing was carried out. Two major type of veins were found to be present, one cemented with carbonate and the other with kaolinite or kaolinite/carbonate. Uniaxial compressive strength and shear tests showed that differentiation of the two types of veins was vital in evaluating the strength of the sandstones, as cementing of the fractures by rigid carbonate minerals can reinstate the strength of the rock masses to that of the intact material. Kaolinite was more susceptible to plastic deformation than carbonates

Jun 19, 1905

By Bakker J. de, P. A. Leest, W. L. Dalmijn, H. J. Glass

The test facility at the Delft University of Technology, in the Netherlands, was characterised. Advantages include the possibility of separating particles with high but different densities up to 9 g/cm3, the ease of adjustment to any required separation density and the absence of moving parts. Simultaneous separation of more than two types of particles is possible and the magnetic fluid is safe and convenient to use compared with other heavy liquids. Disadvantages include loss of magnetic fluid with outgoing particles (cost approx US $10/l) and degeneration of fluid due to bacterial activity, reaction with particles and with surroundings. Only non-magnetic materials can be separated, there is limited potential for scaling up and high investment is required on account of the cost of magnets. Future improvements in the design of the apparatus and the properties of the magnetic fluids can only enhance its attractiveness for commercial applications

Jun 18, 1905

By S. L. Gay

The conventional mass-balance equations used as constraints can lead to flow estimate values of zero even though the flow estimates should be some positive number. This is because many of the constraint equations are satisfied if the flow rates are zero. The way to overcome the problem is to use a slightly different form of the equations. For example, rather than use the conservation of flow of solids as a constraint it is better to use the constraint that the percentage of solids going into a unit equals the percentage of solids coming out of the unit. Examples are given using mineral processing data sets from Mount Isa, Queensland, and Red Dog, Alaska

Jun 21, 1905

By Fearnsides W. G.

Discussion at the The Midland Institute of Mining, Civil and Mechanical Engineers' general meeting held in Doncaster on 27th May 1916, on the paper published in Trans. I.Min.E., vol.LI, 1916, p.409-448, included oral contributions by Lupton A. on the mechanisms of subsidence and water egress and by Kendall P.F. on the validity and accuracy of the contour extrapolation technique and the effect of major faults, together with the author's response

Dec 1, 1916

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