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By NA NA

A round up of recent industry matters. Davis Derby acquisition of Safecom UEP Ltd. Record Output by Longannet Mine.

Jan 7, 1997

By NA NA

Profile of FOSROC, manufacturers and suppliers of products for the mining industry.

Jan 11, 1996

The Council of the Institution of Mining and Metallurgy submitted the report of the affairs of the Institution for the session 1970-71, and the Statement of Accounts for the year ended 31 December, 1970. The statistics given in the report refer to the calendar year 1970. Details are included of membership, officers, representation on other bodies, honours and distinctions, awards, meetings, publications, library, overseas activities, fellowships and grants, the revenue and expenditure account, the balance sheet, trust fund balances, contributing companies, and schedule of investments

Dec 1, 1971

By C. C. Harris

The two best known graphical methods for presenting and comparing comminution data are obtained by linearising the Gates-Gaudin-Schuhmann and the Rosin-Rammler size distribution equations. It is shown that the Gates-Gaudin-Schuhmann equation can cause excessive congestion in the 50 per cent oversize range and that, overall, the Rosin-Rammler is a better procedure. Examples are given

Dec 1, 1971

By Williams J. A.

"Changes proposed in 1969 to modernize legislation governing the exploitation of mineral deposits in the United Kingdom serve as the basis for a discussion of what is considered to be a desirable framework for future legislative proposals.Proposals with regard to prospecting and exploration, evaluation, and acquisition and exploitation are considered, as are suggestions relating, inter alia, to aerial surveys and land restoration.It is concluded that without legislation along the lines proposed there can be no significant revival of metal mining in Britain."

Dec 30, 1971

By R. M. Honey

An attempt is made to summarise the mining law of England, Wales and Scotland. Attention is also drawn to the recent privatisation of the electric power and gas industries and the intention of the present Government to follow suit as regards coal mining. The subject of mining law is discussed under the headings: minerals or rights that have been nationalised or are vested in the Crown; ownership (of land and mineral rights); special customs; tracing of owners; right of support (arising from mining); ancillary rights and easements; obtaining prospecting and mining rights; planning permission; statutory aids to obtaining rights; notes on the history, law and practices of petroleum (onshore and offshore), gas, coal, prescribed substances, gold and silver; electricity; safety, health and welfare; and technical information and boreholes. A correction in the subsequent issue amends errors on p.A75 and A82 and regrets the publication of misinformation on the availability of grants

May 1, 1991

By W. H. McAllister

The paper considers the geology and the coalfields that comprise the Scottish south area. It traces the history of known sources of spontaneous combustion and indicates the collieries concerned, with the position of the seams in the geological series where heatings have occurred. The methods of work over the years are described. It relates in detail the circumstances surrounding a fire at Bilston Glen Colliery in the Lothian Coalfield, and the heating at Killoch Colliery in the Ayrshire Coalfield, and the steps taken to deal with them. It also describes some of the difficulties in steep seam working. Methods adopted to prevent spontaneous combustion throughout the area are discussed, and some detail of the UNOR gas analyser is given. Finally, it comments on the present techniques in use in the area, particularly at Bilston Glen Colliery, to prevent spontaneous combustion.

May 23, 1905

By Schwartz M.

Respect for mining in Botswana is long-standing. This article looks at Africa's most transparent mining regime and some of its ambitious plans. Botswana's mining industry value is forecast to average 5.2% growth from 2014-2018 with solid growth for the diamond sector and acceleration of coal production. Respect for the country's mining regime is maintained in the Fraser Institute 2014 annual survey where Botswana occupies the 26th position of 122 administrations. Botswana's transparency is illustrated by Mupane gold mine near Francistown, Ghaghoo diamond mine in the Gope area and the Morupule coal mine

Mar 1, 2015

By I S. Lowndes, K. Moloney

Diesel powered equipment is currently used extensively in mining and tunnelling operations around the world due to its mobility, flexibility and through selective application to enhance productivity. However, the increased use of diesel equipment has exacerbated the pollutant load (including heat, humidity, exhaust gases and particulates) placed upon the environmental systems of many underground operations. This expansion in the use of diesel equipment has prom pted researchers to evaluate m easure ment and control technology. This paper reviews the recent research conducted in various countries.

Jan 10, 1996

By J. K. Brimacombe, F. D. Richardson

Studies have been made of interfacial turbulence occurring in reactions in which indium, zinc and cadmium, dissolved in amalgams, are oxidised into aqueous phases by ferric or mercurous ions. It has been found that this turbulence occurs when the concentrations of oxidising ions in the aqueous phase become sufficiently great. These concentrations are the same as those at which the mass-transfer coefficients in the aqueous phase increase sharply when both phases are stirred by gas bubbles rising through them. The effects of gas flow rate on the mass-transfer coefficients for zinc in mercury have been established, and the oxidation of pure mercury has been investigated. The relevance of the work to processes involving liquid metals is discussed

Dec 1, 1971

1994 estimates for Porgera are probable and proven reserves of 58 200 000 t of ore grading 5 g/t Au. Gold mineralisation is related to an intrusive complex emplaced at shallow levels in poorly consolidated sedimentary rocks. The complex is located in a zone of fold-and-thrust deformation, whose formation may have been initiated shortly before emplacement and continues locally today. Abundant primary magnetite in the complex gives an intense, 5 km wide aeromagnetic anomaly. The deposit formed during two main stages of mineralisation, the first related to early magmatic-hydrothermal activity and the second representing later epithermal overprinting centred on the Roamane fault. Hydrothermal alteration followed closely on emplacement indicating a close genetic relationship between magmatism and mineralisation. Both stages of hydrothermal activity post-date and overprint early propylitic alteration. Several factors have acted in unison or sequentially to concentrate metals at the deposit, including an extensional or trans-tensional tectonic setting within an arc or collisional environment, the exsolution of a magmatic hydrothermal fluid prior to sulphur saturation in the melt, the development of the hydrothermal system into one favourable for transporting gold, the action of late-stage faulting in focusing epithermal fluid flow, and the role of dissolved gases in promoting fluid phase separation and high-grade ore deposition

Jun 19, 1905

By E. J. Bolitho

"The paper covers the activities of the Government Miners' Training-Schools. It argues that its success is proved by the steady demand for miners trained at the Schools; by the large numbers of ex-apprentices who hold responsible official positions in the industry; and bv the probable expansion of the organization in the near future to meet the never-ending call for trained personnel."

Jan 1, 1947

By J. Ivon Graham, T. D. Jones

This paper presents methods in use in British coal-mines for the suppression of dust. While the effect of present-day treatment will not be apparent for several years, in pits in South Wales, concentrations as high as 50 gm./1,000 cu. ft. were some years ago fairly common in various operations at or near the coal-face, with an average concentration of 20 gm./1,000 cu. ft. Now the average concentration in what were previously dusty pits is probably not greater than 3 gm./1,000 cu. ft.Nevertheless, every effort must be made to improve conditions still further. In South Wales it is claimed that 99% of the coal-faces requiring treatment have been dealt with either by wet cutting, infusion, or hand-spraying. The extent of the treatment by these methods can be gauged by the fact that the total length of coal-faces now being treated by water infusion in Cardiff and Swansea areas is about 33,000 yds., by wet cutting 25,000 yds., and by hand-spraying nearly 14,000 yds. The influence of methods of mining upon dust production is only mentioned very briefly in this review, and there is no doubt that much more is to be learned concerning this aspect. It can be stated, however, that good mining practice is essential to prevent unnecessary dust production, and the problem of dust in mines will be solved only by the closest co-operation between mine managers, workmen, and scientists.

Jan 1, 1947

By C. M. Lesher, R. R. Keays

"The komatnte-associated Fe-Ni-Cu sulphide mineralization at Kanihalda, Western Australia, is generally believed to be magmatic in origin, but a number of postmagmatic processes significantly modified the original distribution, structure, texture, mineralogy and chemistry of the ores. Two important types of mobilized magmatic sulphides are interpillow/interbreccia sulphides and hydrothermal vein-type sulphides. Interpillow and interbreccia sulphides occur interstitial to pillowed or volcaniclastic footwall metabasalts beneath or adjacent to the stratiform contact ore horizons. They are mineralogically and compositionally similar to massive ores (and are similarly depleted in PGE relative to the compositions of bulk samples of mined ores), but normally do not contain the distinctive chalco-phile ferrochromites characteristic of contact ores. They are interpreted as magmatic sulphides that have been mobilized from the overlying or adjacent massive sulphide layer during peak tectono-nietamorphism.Hydrothermal sulphide-quartz + albite veins also occur in the footwall metabasalt and contain unannealed deformation fabrics indicative of emplacement during retrograde metamorphism. The high Ni and Pd contents of these sulphides (7-13% Ni, up to 70 ppm Pd) indicate that the metals have been derived from the spatially associated komatiites and/or contact ores, consistent with the Pd depletion previously inferred for massive ores. Very low Ir contents and high Pd/Ir ratios of the vein-type sulphides confirm an aqueous transportation-deposition mechanism; hydrothermal transfer of PGE results in strong decoupling of Pd from Ir.There appears to be a complete continuum of sulphide mobilization at Kambalda ranging from whole-scale phy sical dislocation (fault offset ores) and selective mobilization (stringer sulphides) through nietamorphie replacement (interpillow/interbrec- cia sulphides) to jiydrothermal dissolution and redeposition (vein-type sulphides)."

Jan 1, 1984

By G Williams

Discussing equipment, systems of work, the need for updated programmes of local seismic exploration, and developments within the South Wales coalfield.

Jan 1, 1993

By D. Newman

Mineral production in the Highlands and Islands of Scotland during the last ten years has been confined to the sporadic production of industrial minerals—for example marble, anorthosite, limestone, talc and silica. From 1962 onwards there has been an upsurge in mineral exploration in the Highlands, increasing in tempo from 1966 onwards due to the efforts of the Institute of Geological Sciences, the Highlands and Islands Development Board, and private and public companies. Geological, chemical and economic aspects of some of the more interesting mineral prospects are discussed: these include anorthosite, feldspar, magnetite, quartzite and brucite marble. Reference is made to a geochemical survey undertaken in the Rosehall district of Sutherland, the results obtained being summarised. Problems that affect the future of mineral exploration in the Highlands are stated.

Dec 1, 1971

By Li Shibo, C. Halls

The compositions of olivine, pyroxene and chromite from the Proterozoic ultramafic complex are analagous to those of cumulate ultramafic rocks of tholeiitic origin, suggesting that the parent magma may have been tholeiitic rather than komatiitic. The complex contains economically significant Ni-Cu sulphide mineralisation. The high sulphide/silicate ratio is best explained in terms of the segregation of sulphides from a large volume of magma, of which all but the ultramafic cumulate fraction has since been eroded. Platinum-group minerals that have been identified include sperrylite, moncheite, native platinum, froodite, merenskyite, michenerite and Pd-rich pentlandite lamellae exsolved from pyrrhotite. They are characteristically found in close association with chalcopyrite, either along the contacts between hydrosilicate and sulphide grains or in cracks within pentlandite and chalcopyrite, which may also be intergrown with galena. Crystallisation from a Cu-rich residual magmatic liquid also enriched in Pt, Pd, As, Sb, Bi, Te, Zn and Pb is postulated.

Jan 12, 1993

By W. Petruk, M. J. Matos

An aplite ore from Guarda in northern Portugal, containing albite, microcline and quartz and muscovite gangue was studied to identify conditions for extracting the feldspar minerals. The large amounts of quantitative mineralogical data needed to evaluate grinding behaviour were provided by automated image analysis. The images were acquired on polished surfaces by measuring back-scattered electron signals produced with a microprobe. Minerals were identified from X-ray spectra and discriminated by grey level and element-characteristic X-rays. The quantities and size distributions of the minerals were determined by measuring thin sections of unbroken ore to predict the grind required to liberate the feldspars. The ore was then ground to -1.7 mm, polished sections were prepared from sieved fractions and the quantities of mineral species and apparent total liberation were determined by analysis. The predicted and measured liberations were compared and the grinding behaviour of the ore interpreted. In an appended correction, 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 H. L. Paterson, R. R. Keays, M. J. Donaldson, D. J. Boyack, M. F. Smith, J. J. Gresham

"Albite-rich sedimentary rocks that contain abundant Fe sulphides occur in the lower portion of the ultramafic sequence at Kambalda and their broadly antipathetic relationship to most of the nickel orebodies is well documented. These sediments generally contain less than 0.1% Ni, but nickeliferous equivalents with 0.3 to >6% Ni occur locally in close spatial association with more typical volcanic peridotite-associated massive, matrix and disseminated ores. Nickeliferous sediments have been mined at several locations at Kambalda but, collectively, they constitute less than 2% of the total Kambalda nickel reserve. The nickeliferous sediments occur both on the ultramafic-footwall basalt contact and within the lower part of the ultramafic sequence, and are usually less than 5 m thick. They are commonly finely laminated rocks with a cherty appearance, composed essentially of layers of albite+quartz±amphibole, alternating with pyrrhotite+pentlandite±pyrite layers. Some contain a minor amount of carbon. The sediments are only of ore grade (> 1% Ni) immediately adjacent to massive Fe-Ni-Cu sulphides, which are interpreted as normal magmatic ores on the basis of geochemistry and the presence of distinctive ferrochromites. The nickel content of the sediments decreases to background levels (<0.1%) within about 20 m of the massive sulphides. In most locations the massive sulphides clearly have been emplaced tectonically within or adjacent to the sediments, which are commonly highly deformed. Typical nickeliferous sediments contain about 1% Ni, 0.1% Cu, 0.1% Zn, 400 ppb Pd, <0.2 ppb Ir and 10-200 ppb Au. They have lower Ni/Cu (average 10), higher S/Ni (average 6) and higher S/Se (average 11 200) than associated massive sulphides (average 40, 4.8 and 7400, respectively). The Pd/Ir ratio of the nickeliferous sediments (typically > 1000) contrasts markedly with that of associated massive sulphides (average ca 16).The high Pd/Ir values are similar to those which have been reported for hydrothermal Fe-Ni sulphides and barren sulphidic sediments of probable volcanic exhalative origin. They preclude a direct magmatic origin for the sulphides in the nickeliferous sediments, though S/Se and S isotope data indicate a magmatic source for the sulphur. The restriction of nickeliferous sediments to within about 20 m of normal magmatic sulphides and the lack of a widespread Ni dispersion halo suggest local redistribution of originally magmatic Ni. This probably occurred by diffusion and hydrothermal mobilization during deformation and amphibolite-facies metamorphism. Although not totally ruled out, a volcanic exhalative origin for the Ni seems unlikely."

Jan 1, 1984

By J. S. WARWICK, E. J. Browning

Ignitions continue to occur underground, sometimes leading to major explosions. There has been considerable effort in the UK, and more widely in the European Community, to formulate the best ventilation practices and other means of minimising these incidents. Practices and procedures to prevent ignitions are discussed in the light of the risks from current mining methods.

Jan 1, 1993