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By Xuejing Xie, Tianxiang Ren

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). Standardised stream-sediment sampling procedures have been used in mountainous and hilly terrains. Special sampling procedures were developed for application in remote environments, such as high mountains, desert, semi-desert, karst and loess-covered regions. The diversified analytical methods used in more than 20 analytical laboratories participating in the project have been unified into two multi-element, multi-method analytical systems. A unified data monitoring procedure was developed based on primary and secondary standard samples. To date the project has covered about 4 000 000 km2 and the aim is to complete the coverage within the present decade

May 1, 1991

By P Cochrane

Our ability to generate information and transport it about the planet on super highways of optical fibre is about to change the way in which we communicate, work and live. There is not a single aspect of our future that will go untouched by the communication and computing revolution that Is now upon us. The change we are about to witness will overshadow the impact of the printed word, industrial revolution and physical transport. The next major wave of information technology (TT) development will focus on the delivery of information and experience on demand, in the right form, at the right time, at the right price, to fixed or mobile terminals anywhere, over networks of optical fibre, radio, satellite and optical wireless. Bandwidth, distance and time will no longer be significant cost elements as service and access become dominant.

Jan 7, 1996

By R. R. Liebenberg, M. I. Brittan

The kinetics of the copper segregation process has been investigated. The experimental strategy used to isolate the rate-controlling reaction step is described. This step was found to be the chloridisation of the oxide copper minerals in the ore. The link between the rate of chloridisation and the overall rate of segregation is demonstrated experimentally. The influence on the kinetics of the various parameters in a TORCO system is examined and the implications are discussed

Dec 1, 1971

By R. Phillips

The low concentration of diamond in workable deposits requires very large samples for grade estimation, and results, even then, may be erratic and difficult to interpret. Although the Poisson probability distribution cannot accurately describe the occurrence of diamond, it is suggested that it gives a better estimate of grade than conventional methods, even from single samples. Examples illustrate the simple calculation required.

Dec 1, 1971

By Briggs H.

The illustrated device uses the principle that the lamp can burn with a smaller inlet passage if the air is rich in O2 and that the size of the inlet can be made a measure of O2 percentage. The appliance consists of an adjustable cut-off applied to the inlet of a safety lamp of the improved Gray pattern. Precision is assessed from tables of calibration tests in air contaminated with blackdamp of CO2:N2 composiiton 1:5.67 at temperatures of 40-70 degrees F. Results are presented of tests at St. Germain's colliery, of tests in air contaminated with pure CO2 and of air contaminated with both blackdamp and inflammable gas; published ranges in mine-air blackdamp compositions are tabulated as ranging from 90.06% N2 to 43.90% CO2. When firedamp is present at 1.25-2.5%, its content must first be estimated by means of the cap and a fifth of its value then deducted from the lamp reading for O2

Dec 1, 1916

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. M. Smith

This resume provides an account of the work of the Bureau and it's establishment by an Act of Parliament in August 1916. The Medical Bureau is concerned solely with the administration of the medical provisions of the Act. Its main functions are to conduct and to direct or control the medical examinations provided for in the Act. The paper covers the changes in type of silicosis, classification into the three legal stages of silicosis, cancer of the lung and tuberculosis.

Jan 1, 1947

By T. Sharma, T. C. Rao

Laboratory studies have been carried out on acid leaching as a possible route for the extraction of potassium from glauconitic sandstone. Leaching efficiencies with sulphuric, hydrochloric and nitric acids were investigated. The effects on potassium dissolution of temperature, concentration and type of acid, stirring speed and leaching time were also studied. The results show that it is possible to recover 87.5, 93 and 85% potassium with 5 M H2SO4, HCl and HNO3, respectively. During the initial stages of the sulphuric acid leaching process the chemical reaction at the mineral surface is the rate determining step, whereas during the later stages diffusion through the product layer is rate-controlling. Overall, the process follows a mixed-control model that includes both chemical reaction and diffusion. The activation energy for the dissolution of K was found to be in the range 25.79-106 kJ/mol.

Jan 12, 1992

By Mohammed Ali Shah, Martin Waller

The mining industry depends to a large extent on the availability of high performance equipment. For drilling this means a requirement for well engineered, reliable machines with mechanised handling and widespread utilisation of automatic control. Such machines enable performance optimisation of drilling operations and integration into a high productivity mining system. A review is presented of the current status of drilling technology as applied to the mining and minerals industry. This covers developments in: drill bit materials and design; drilling techniques; machine design; mechanisation; automation; and drilling control. It also covers the ways in which current and future mining methods and practices will influence the applications and demands placed on drilling activities. The probable impact of current research on the industry is discussed.

Jan 12, 1992

By P. W. Edwards

"This paper summarises many experiments conducted, and how in North American industry the use of aluminium in treatment and prevention has been adopted widely. The Pottery Insurance Co., Ltd., made it possible for me to investigate conditions in Canada and the U.S.A., and I thank them for permitting me to submit this short paper- an abstract of my report to them."

Jan 1, 1947

By D. J. Allan, W. R. Wilson

For conventional aerospace aluminium alloys of the 2000 (copper) and 7000 (zinc, magnesium) series the recycling of process scrap from both metal suppliers and aircraft manufacturers is a well-established, worldwide industry. The recent introduction of a new family of alloys that incorporates lithium has posed a new challenge to the recycling industry owing to the high cost of lithium, its high reactivity to the atmosphere and to refractories and its absence from the specifications of all other registered alloys. Various process options for recycling have been identified, but vacuum distillation has been selected as the most cost-effective and technically feasible solution. Experimental work established that the separation of Li from AI-Li scrap is feasible and an industrial process has been designed. The economics of Li recovery are very sensitive to the AI-Li content of the feed material. Owing to the design of aerospace vehicle manufacturing plants it is expected that the swarf will be mixed with other alloys. A method of enriching this feed has been developed that is based on the control of swarf morphology by thermal and mechanical treatments as a precursor to eddy-current separation. After eddy-current separation and vacuum distillation small proportions of Li are retained in the AI residue. The effects of this on the properties of conventional AI-Si shape-casting alloys were investigated and safe threshold levels have been established.

Jan 4, 1993

By A. H. G. Mitchell

Gold-poor and gold-rich porphyry and epithermal gold-silver deposits of Caenozoic and Cretaceous age in the western Pacific and central and eastern Europe are confined to predominantly andesitic continental margins and island arcs. The arc volcanic rocks overlie a complex non-oceanic basement of stacked nappes, the uppermost of which is often ophiolitic. The emplacement of ophiolite triggered a reversal of tectonic polarity, subduction and arc magmatism. Andesitic volcanism and the formation of a strato-volcano were followed by the ascent of magma and porphyry copper mineralisation. Regional propylitic alteration came from convecting, predominantly meteoric fluids. Magmatic degassing caused advanced argillic alteration. This is commonly unmineralised in perched water tables, but may sometimes host high sulphidation gold or enargite gold at deeper levels within the propylitic zone. The onset of extensional stress after the andesitic volcanism allowed meteoric water to circulate to depths of 5 km or more, with consequent cooling of an ascending magma body at depth and the development of low sulphidation epithermal gold mineralisation near and immediately above the sub-volcanic basement surface. All andesitic arcs are mineralised. Regional controls on their ore potential include the level of erosion and geological features in the basement that focus the ascent of fluids. Differences between the mineralisation of the European and the western Pacific arcs may reflect the presence of older, more granitic basements in many of the European arcs.

Jan 12, 1992

The report of the Annual General Meeting of the Institution of Mining and Metallurgy held on Thursday, 20 May, 1971, in the rooms of the Geological Society of London, Burlington House, Piccadilly, London, W.1, at 4 p.m. (Chairman : M. J. Cahalan, President) includes details of awards and prizes presented to William Justin Kroll, Sir Gordon Colvin Lindesay Clark, John Convey, Evert Hoek, Peter Reginald Dawson and Christopher Michael St. John

Dec 1, 1971

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 Eric Forssberg, Vigen Zeng

During mechanical grinding high intensity vibration is emitted that contains information on the mill's operating state. Tests, using a laboratory ball mill, studied the influence of operating parameters on the vibration signature. The parameters studied were: mill speed; powder filling; pulp density; grinding period; and pulp temperature. Vibration signals were detected by an accelerometer, amplified by a vibrometer and recorded onto digital audio tape. A digital oscilloscope converted the signals into IBM-compatible data format. Digital signal processing and multivariate data analysis were carried out with specially developed software. The power spectral density was estimated from the time-domain vibration signal. Four new latent variables were used to describe changes in the vibration spectra. A relationship was established between operating parameters and latent variables which could form the basis of a quick and automatic method of monitoring operating parameters in ball mill grinding.

Jan 4, 1993

By R. J. Pine, J. S. Coggan

Distinct-element modelling has been used to study the mechanisms associated with observed deformation of the western face of the quarry. A complex failure mechanism involving distinct planar surfaces that was proposed for a slope failure in 1967 has been modelled and shown to be plausible. In addition, deep-seated flexural toppling may contribute to the slope instability. Modelling has confirmed the detrimental influence of a raised water-table on the stability of the slope and also indicates that the observed cyclic opening and closing of tension cracks may be attributed to seasonal rise and fall of the groundwater level

Apr 1, 1996

By M. Schwartz

Mining in Argentina is diverse in terms of the number of minerals extracted from the country, but also in terms of the varied approaches and attitudes of mining investors and their trust in the country's individual provinces. Laws are discussed, investment attractiveness and taxation.

Jun 1, 2015

By C. J. V. Wheatley

Recent studies of the mineralisation at Avoca in southeast Ireland, Parys Mountain in Anglesey, and Coniston in the Lake District result in the proposal of a new metallogenetic model for mineral deposits in the Southern Caledonides. A regional pattern of metal zoning exists, an axial belt, including the major copper deposits, being bordered by areas with lead-zinc deposits. Conformable lenticular pyritic zones occur in the central belt, closely associated with acid volcanic sequences and, often, post-dating them. These zones are thought to have been formed in a marine environment, mineral growth taking place below the sediment-water interface, whereas magnetite-rich zones developed under different Eh and pH conditions. Stockworks containing appreciable copper and, in some cases, lead and zinc were developed at a later date, stratigraphically below the pyritic zones, by migrating hydrothermal chloride and metal-rich fluids. Complex lead-zinc-pyrite mineralisation resulted from the reaction between pyritic zones and the final fraction of the hydrothermal fluids. Crosscutting vein-type fissure infilling mineralisation occurs in every mineral field. These deposits apparently comprise a pulsatory metasomatic sequence, closely related to tectono-stratigraphic controls, ore localisation being influenced by the coincidence of suitable structures and pyritic shale horizons. The implications for mineral exploration are considered and it is concluded that the model offers an explanation for the existing pattern of metal zoning; and it may have wide applicability to mineral deposition in geosynclinal sequences.

Dec 1, 1971

By E. C. I. Hammerbeck

"Geological controls and constraints in space and time define the milieu of the nickel deposits of Southern Africa. Primary, magmatic deposits are of two types, e.g. synvolcanic or syntectonic deposits confined to certain orogenic domains, and those related to intracratonic, post-orogenic magmatism, e.g. the Great Dyke, the Bushveld Complex and the Insizwa intrusion. Epigenetic and supergene deposits form a separate, unrelated group and are of minor economic importance.The metallogenic evolution of syntectonic nickel deposits is particularly well illustrated in the Zimbabwean Province, where the relationships between Archaean greenstone development and nickel mineralization are best illustrated. Volumetrically subordinate, nickel-poor greenstones in the 3500 m.y. old Sebakwian Group are followed by more common komatiite development in the Lower Greenstones (3000 m.y.), and, finally, by very significant komatiites with important nickel mineralization in the 2700 m.y. old Upper Greenstones of the Bulawayan Group. Comparable nickel mineralization is not known in the Raapvaal Province, in spite of ubiquitous komatiitic magmatism of the Onverwacht Group (3500 m.y.) and other greenstone sequences. No komatiitic rocks younger than about 3200 m.y. are known in this region, orogenic activity in the Kaapvaal tectonic province having ceased at about 3100 m.y., whereas the Zimbabwe Province remained tectonically active until at least 2600 m.y.The tectonic environment, host-rock petrology and mode of emplacement, as well as some details of the nickel mineralization, are the parameters employed to classify the Southern African magmatic nickel deposits. A rating of the deposits is introduced that reflects the original resources of the deposit, its average nickel content, its mining history and potential to facilitate ready comparison with and assessment of the nickel deposits listed in the classification, as well as some important nickel deposits worldwide."

Jan 1, 1984

By L. T. Matthews, C. E. Loo

During sintering, porous ore particles are easily assimilated by liquid melt. Two simple models of the process are considered: the dissolution of a solid by a liquid and the penetration of a liquid into a porous solid. Laboratory sintering studies covering a range of experimental conditions were undertaken to characterise the assimilation of large particles of ore and flux by melts formed from different mixes of fines. For ores, the process appeared to be complicated by the detachment of fines from the ore surface prior to melt formation, according to the mass of adhering fines and surface roughness of the particle. This delayed the onset of assimilation and sometimes reduced it, although melt penetration was fast and effective. Studies using different temperature profiles suggested that the assimilation of haematite was controlled by the transport of Fe2O3 away from the surface of ore particles. The assimilation of limestone depended more on thermal conditions than on the three magnesia-bearing minerals considered. Changing the composition of the initial melt significantly altered the extent of assimilation of ores and limestone, but again had a less marked effect on the magnesia-bearing fluxes.

Jan 8, 1992