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1. Book review • World mineral statistics 1974 to 1978. Production: Exports: Imports. London, H.M.S.O., Institute of Geological Sciences, 1980. (Reviewer: R. P. King) This edition is the third in a regular series prepared by the Institute of Geological Sciences. It is a useful compilation of statistics on the production, export, and import of fifty-eight different mineral commodities. Each mineral is listed by country, and a table is provided for the annual production, the annual imports, and the annual exports for each commodity included. However, some commodities are treated in considerably more detail; for example, aluminium and bauxite have tables under the following headings: Production of Bauxite, Production of Alumina, Production of Primary Aluminium, Exports of Bauxite, Alumina and Aluminium, Imports of Bauxite, Alumina and Aluminium. The information presented is the latest official information available from primary sources; the compilers have not relied on data from secondary compilations. This publication will be of considerable assistance to all who are concerned with the trading of mineral commodities and their production.

Jan 1, 1981

By A. R. Barnes, A. F. Newall

Keywords: Pyrometallurgy, furnace, smelting, spinel, PGM, phase diagrams As Merensky reef ores are replaced by UG2 ores, chromium levels in PGM smelting furnace feeds have steadily increased. Increased chromium levels lead to operating problems. Attempts to increase the chromium solubility in the slag by a variety of techniques create other difficulties. The authors have developed a technique for removal of the chromium spinel interface along with the matte for subsequent separation outside the smelting furnace by utilising differential solidification in the ladle. The process has been patented internationally with support from the Innovation Fund.

Jan 1, 2006

By Doris Gardner

On Friday, 6th June, 1986, an SAIMM party of32 set out at 06h30 for a tour of Duvha Opencast Colliery, Lesedi Village, and Duvha Power Station-all situated just outside Witbank. Duvha Colliery On arrival at the mine, the party was met by Mr. Colin Kolver, Assistant General Manager, and the guides for the morning. After refreshments had been served, Mr. MacDonald, General Manager, welcomed the tour, and a series of slides on the opencast mine and Lesedi Village were shown.

Jan 1, 1986

The November General Meeting of the Branch was held in the St. Helena Club at 8.00 p.m. on the 17th November, 1970. Mr J. N. Saunders (Chairman) was in the chair. There were also present six fellows, N. A. Honnet, C. J. Isaac, J. G. Kirchner, (Committee Members), J. M. Meyer, S. L. S. Swart and J. W. Wilson; seven members, D. V. Baum, M. de Lange, A. H. Edwards, G. J. G. Emere, E. R. Penny, G. P. Rundle, C. G. J. Vermeulen; six graduates, N. Mayer, H. Miller, E. J. Shillaber, P. J. H. Short, M. H. Smith, T. R. Stromsoe; five associates, M. Andriesse, A. E. Hooper, A. Paschalides, R. L. Solms, W. M. Todd; one student, J. C. Simms and 14 visitors. Apologies for absence were received from Messrs L. O. W. Leimer and G. Y. Nisbet. MINUTES OF THE ANNUAL GENERALMEETING The Minutes of the Annual General Meeting held on the 27th August, 1970, were taken as read. Their adoption, which was proposed by Mr N. A. Honnet and seconded by Mr J. G. Kirchner, was carried unanimously. MINUTES OF THE JULY GENERALMEETING The minutes of the General Meeting held on the 8th July, 1970, were taken as read. Their adoption, which was proposed by Mr C. J. Isaac and seconded by Mr J. G. Kirchner, was carried unanimously. GENERAL BUSINESS Members were advised that no more applications could be entertained for the visit to Western Holdings; they could, however, still apply to visit Welkom Mine and Harmony. TALK The Chairman invited Mr A. Paschalides to deliver his talk on 'Controlled blasting in stopes and new explosives developments'. The presentation proved to be of great interest to the meeting and lively discussion followed the talk. Mr N. A. Honnet proposed a vote of thanks to Mr Paschalides on behalf of all members of the O.F.S. Branch. CLOSURE The Chairman thanked Mr Paschalides for his talk and all present for their attendance, and as this was the last meeting for 1970 he wished all members a Merry Christmas and a Happy New Year. He declared the meeting closed at 9.30 p.m.

By C. N. Harman, N. S. S. Rama Rao

Production of Ferro-alloys through submerged electric arc furnace involves use of electric power as one of the major inputs. Hence the production by this power intensive process can be made economically more competitive if the specific power requirement for smelting each ton of the product is brought down. This becomes all the more necessary where the power cost is comparatively high, like in India. Since the day FACOR started production of Ferro Chrome in 1968, briquetted chromite fines along with lumpy ores were used as feed. Subsequently the increase in the proportion of briquettes and reduction in lumpy ore helped in increasing the use of chromite fines and also brought down the specific power requirement. Meantime FACOR had been closely watching the technical development of use of sintered pellets in Outokumpu and SRC Processes which need still lower specific power. But the high capital requirement for a pelletisation plant kept FACOR from introducing pellets feed to their Ferro chrome furnaces. So this was postponed to be adopted in future. In February 2004 in the ?1st Ferro-Alloys India?, a paper [1] was presented by Dr. Amit Chatterjee. In the questions period after the presentation of the paper there came up a discussion in which it was revealed that with the Indian high grade chrome ores it was not possible to make sufficiently strong pellets, unless a larger percentage of bentonite is used as binder. This is because the Indian high grade Chrome ores have different mineralogy of gangue content compared to low grade ores in Finland and South Africa. Higher usage of bentonite gives rise to higher slag volume and this would result in increased specific power. Since FACOR had plans to go in future for sintered pellets feed, this gave rise to a doubt on success of pelletisation for Indian high-grade chrome ores. This prompted FACOR to take up experimental production of sintered chromite pellets and use of the same in one of their existing furnaces for production of high carbon Ferro chrome. The results are encouraging and are summarized in the paper.

Jan 1, 2007

By C. T. Connor, O&apos

The 10th Annual UCT -US Minerals Processing Symposium was held at the Van Riebeeck Hotel at Gordon's Bay from 31 July to 2 August 1991. The conference was attended by 133 delegates representing a broad cross-section of the mining and metallurgical industry in South Africa. For the first time the Symposium, which was celebrating its 10th anniversary, was extended to two days. A cal for papers was announced and the organizers were inundated with responses resulting in a very full technical programme which consisted of 29 oral and 15 poster presentations.

Jan 1, 1991

By V. Matou?vek

The paper addresses pipe flows of aqueous medium-sand slurries at velocities lower than the deposition-limit velocity. Laboratory test results including measurements of particle concentration distributions are used in order to describe a flow with a (pseudo-) linear concentration gradient above a stationary bed. Particle dispersion within the flow is evaluated and a stratification-ratio equation is formulated, estimating a portion of contact load in the flow. The formula is incorporated in the proposed predictive model for the hydraulic gradient for a medium-sand flow above a stationary bed.

Jan 1, 2007

By V. Matou?ek

The paper addresses pipe flows of aqueous medium-sand slurries at velocities lower than the deposition-limit velocity. Laboratory test results including measurements of particle concentration distributions are used in order to describe a flow with a (pseudo-) linear concentration gradient above a stationary bed. Particle dispersion within the flow is evaluated and a stratification-ratio equation is formulated, estimating a portion of contact load in the flow. The formula is incorporated in the proposed predictive model for the hydraulic gradient for a medium-sand flow above a stationary bed.

Jan 1, 2007

1. Book reviews Mining and metallurgical practices in Australasia. Melbourne, Australian Institute of Mining and Metallurgy, 1981. $40 (incl. surface postage). Reviewer: M. G. Atmore Coal mine ground control, by Syd. S. Peng. 1978. Reviewer: C. F. Engelbrecht Sixth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity, July 31 -August 2, 1979. Pittsburgh, School of Engineering of the University of Pittsburgh, 1980. Reviewer: S. T. J. van Rensburg This book is a useful general reference volume on the topics covered provided a great deal of technical detail is not required from it. It consists of 29 papers, which are arranged under 6 headings. Flotation agents and processes. Technology and applications, edited by M. W. Ranney. Park Ridge, D.S.A., 1980. $48. Reviewer: R. P. King 2. New books Project control manual, by Sven R. Red. 250 pp. in loose-leaf binder. U.S. Al47. (Obtainable from the author at Bray Studios, Windsor Road, Windsor SL45 UG, England.) Manganese deposits, by Supriya Roy. London, Academic Press, 1981. 400 pp. Joint preparation for welding (set of overhead-projector transparencies). Abington (England), The Welding Institute, 1980. £34 per set. Electron micrographs of clay minerals, by T. Sudo,S. Shimoda, R. Yotsumoto, and S. Aita. Amsterdam, Elsevier, 1980. 228 pp. Dfl.150. Weld pool chemistry and metallurgy. Abington (England), The Welding Institute, 1980. 357 pp. $27. 3. New journal ...being known as Gliickauf + Translation, at an annual subscription of 396 DM for 24 issues per year. It is available from Verlag Gliickauf GmbR, D-4300 Essen I, P.O. Box 103945, Federal Republic of Germany. 4. Canadian MRI publications During 1980 the Mineral Policy Sector introduced a new series of reports identified by the prefix MRI. These cover internal studies and analytical works on a wide variety of subjects, that for one reason or another, do not reach the publication stream of the regular series yet may be of interest to readers in this 'unpublished form'. Twenty-four such titles are listed below. Exploration planning A series of professional advancement seminars for the mineral industry is to be held at Rhodes University from 12th to 20th August, 1981. The series, entitled 'Economic Guidelines for Exploration Planning', will be conducted by Professor B. W. Mackenzie, and the attendance will be limited to 30 participants. The seminars are intended Seminar on Geostatistics A seminar for mining executives on Geostatistics and Decision Making in the Mining Industry is to be held in Toronto from 23rd to 25th September, 1981. v

Jan 1, 1981

National Coal Board. Gate belt conveyors. London, H.M.S.O. (Price 95p.) Although the preface of this handy little book states that it has been written for the guidance of miningoperation trainees, it will prove valuable to the practising engineer as well. NIM reports Report no. 1733 A mineralogical investigation of weathered carbonatite from Salpeterkop. (14th Apr., 1975; re-issued 28th Feb., 1978). Report no. 1823 The recovery of gold and pyrite from a residue dump at Crown Mines. (10th Jul., 1976; re-issued 28th Feb., 1976). Report no. 1829 An investigation of weathered carbonatite from Salpeterkop. (20th Jul., 1976; reissued 28th Feb., 1978). Report no. 1932 A BASIC computer programme for the evaluation of intensity data from the Telsec Lab-X-250 Analyser. (12th Jan., 1978). Report no. 1940 The extraction of the noble metals with n-octylaniline,and its application to the analysis of platinum-bearing materials. (30th Jan., 1978). Report no. 1945 Analyses of the NIMROC reference samples for minor and trace elements. (28th Feb., 1978). International futures conference A conference entitled 'The Road Ahead' is being organized by the 1820 Settlers National Monument Foundation to be held in Grahamstown from 3rd to 7th July, 1978. Conference of metallurgists The technical programme has been established for the 17th Annual Conference of Metallurgists sponsored by the Metallurgical Society of the Canadian Institute of Mining and Metallurgy. This year the Conference will be held in Montreal, Quebec, on 27th to 31st August, 1978, together with the 8th Hydrometallurgy Meeting.

Jan 1, 1978

By C. P. Smyth

Large volumes of quantitative geochemical data, presenting a formidable interpretation task to geologists, are generated in the course of exploration drilling for new ore deposits. The incorporation of geological expertise into computer programs developed for the interpretation of this data would improve the speed and accuracy with which it is interpreted. A detailed analysis of the geochemical log interpretation problem, together with a survey of relevant research in Artificial Intelligence and petroleum well- logging techniques, confirms, that artificial intelligence, particularly as developed in the fields of expert systems and pattern recognition, provides techniques for implementing such data interpretation programs. In addition, it provides data analysis techniques significantly more powerful than those currently applied to geochemical data, and very appropriate to the hypothesise and test' character of mineral exploration problem-solving. The conversion of raw borehole log data to meaningful higher level geochemical entities, in terms of which geological reasoning may take place, is a critical step in applying these techniques to log data analysis. A method of achieving this conversion as an exercise in signal-to-symbol transformation is presented.1

Jan 1, 1987

By C. M. Suhr

n order to validate the borehole analysis valuation procedure commonly used in the South African gold mining industry, a simulated orebody was used to create borehole values which would serve as data for the procedure. After confirming the distribution, calculating the variance size of area relationship, estimating the block variance, and calculating a profit measurement for each set, comparisons were made to the known population parameters. Results show only one overall bias (in the estimation of the lognormal third parameter), which is carried throughout the analysis. The remainder of the analysis is unbiased, validating the procedure.

Jan 1, 1987

By Richard J. Robbins

Raise and shaft drilling, a continuing development RICHARD J. ROBBINS* (Visitor) Although the past decade has witnessed many improvements in large-diameter drilling machinery for the boring of raises, there is still room for improvement both in operational use and in the design of equipment. Some of the available machines are described and illustrated, and it is concluded that the possibilities of new systems and designs should continually be re-assessed since the factors that determine their feasibility, such as bore diameter, cutter costs, and penetration rates, are changing rapidly.

By P. Saayman

The mining industry has much potential for automation. A great deal of work has been done on this subject and is still ongoing. With automation comes the possibility for optimization, because more information is available and actions can be repeated with more accuracy. This paper looks at possible solutions to the problem of optimizing the autonomous vehicle dispatch system in an underground mine. Possible optimization strategies are evaluated using a simulated environment. The majority of the results indicate that improvements on current methods are possible. Keywords: mining automation, simulation, vehicles, dispatching strategy, optimization.

Jan 1, 2006

By G. A. Brown

A colloquium on industrial minerals entitled' A Strategy for Growth in the Industrial Minerals Sector' was held at Mintek on 5th November, 1991, under the auspices of the Extractive Metallurgy Sub-Committee of the SAIMM. The SAIMM had not been previously active in the field of industrial minerals, and the programme was designed to appeal to the middle management of mining and manufacturing companies in the industrial-minerals field. A total of 86 registered for the Colloquium, a predominance of the delegates (65 per cent) being non-members of the SAIMM. Two overseas delegates were registered after announcements

Jan 1, 1992

By Nielen van der Merwe

Mr Janisch' s comment' in the August issue on Dick Stacey's remarks about safety factors indeed requires wider debate. The example he quoted to illustrate the successful application of the safety factor concept in coal mining, namely the Salamon formula, is to my knowledge the only recognized application of that concept. Not only that, but that particular formula should be used only for what it was intended, namely to prevent major disasters. It was never intended to indicate long-term pillar stability, and it should not be used for that.

Jan 1, 1993

By F. L. D. Cloete, M. C. Coetzee

This study was aimed at a comparison of the efectiveness of a new axial-flow type of mixer impeller (the Prochem design) with the traditional inclined-blade turbine. The intended application of the mixers was in carbon-in-pulp plants for the extraction of gold from cyanide-leached pulps. The first part of the project involved water and ion-exchange resin, and measurement of the power drawn by the various sizes of impeller to fully suspend the resin. The rate of reaction between the resin and the solution was measured as a function of the power input to the mixer. In the second part of the project, use was made of activated carbon, silver cyanide solutions, and ore pulps. The rate of absorption of silver from the solutions and pulps was determined, as well as the rate of attrition of the activated carbon caused by the various impellers in clear water. The Prochem design of axial-flow impeller was shown to fully suspend solids at only one-quarter of the power requireabyan inclined-blade turbine of similar size. The axial-flow pattern produced was responsible for the more uniform vertical concentration profile of suspended beads produced by the Prochem design. These measurements verified the observations of other researchers that the rate of reaction is not affected by the ;design of impeller provided that al the solids are fully suspended. The Prochem design of impeller therefore achieved the same reaction rate as the conventional turbine at a quarter of the power input. The atrition rates of activated carbon could be correlated, in terms of the energy absorbed, by the same equation for al the impellers. Higher concentrations of activated carbon increased the amount of carbon fines produced. These results emphasize the importance of designing mixers for minimum power consumption.

Jan 1, 1989

By I. E. Teymenson, N Fedunets

Mining-metallurgical complex is the base of any economics and influences directly on practically all branches of world economics. Therefore the task of estimation and selection of investment decisions in mining industry adequate to modern market conditions and the task of decreasing multidimensional alternatives selection uncertainty are very actual. An uncertainty of investment alternatives is explained by a number of reasons, main of which are a presence of several investors types, an unstable situation on the market and an absence of evident relations between appraisal criteria used. Maximum increasing of formalization and objectivity of information technologies applied for an estimation permits to reduce the uncertainty of investment variants estimation. A number of principled innovations, allowing to solve the task of decreasing of multidimensional alternatives selection uncertainty, are introduced into the information technology of estimating and selecting investment decisions in mining-metallurgical branch, developed by us. In the article the necessity of including a cognitive model into developed selection mechanism, which allows to take into consideration inter-influences of used critera, has been grounded. Besides, the forecasting model considering interconnected time rows has been applied for increasing the world conjuncture forecast quality. Further in the article main metrics types have been characterized and application of weighted Chebyshev’s metrics as the most compromised from all studied metrics for variants selecting has been proved, and also the developed procedure of directional search of effective compromise decisions has been described. Brief characteristic of designed instrumental means of multi-criteria variants estimation and selection finalizes the article. In conclusion expedience and efficiency of using the developed information technology for reduction of multidimensional alternatives selection uncertainty have been grounded.

Jan 1, 2003

1. Book reviews Geostatistics for natural resources characterization, edited by G. Verly, M. David, A.G. Journel, and A. Marechal. Hingham (MA 02043, U.S.A.), D. Reidel Publishing Co., 1984. Pt I: 606 pp. Pt 11: 518 pp. U.S.$135,50 per set. Reviewer: D.G. Krige Magnesium, the international perspective, by Peter King. London, Financial Times Business Information Ltd, 1984. £120. 147 pp. Reviewer: D.G. Maxwell 2. Mintek reports Report M156 A kinetic study of the reactions of certain gaseous sulphur compounds with iron. Report MI57 Reaction mechanisms in the reduction of Winterveld chrome spinel with graphite and carbon. Report MI72 Computer programmes for the control and datamanipulation of a sequential X-rayfluorescence spectrometer. Report MI77 A proposed test for the determination of the grindabi/ity of fine materials. Report MI86 A survey of the erosion, corrosion, and abrasion of material-handling systems in the mining and mineralprocessing industry. 3. New journal Advanced materials & processes, issued monthly by American Society for Metals (Metals Park, Ohio 44073, U.S.A.). CIM conference The combined 24th Annual Conference of Metallurgists and the 15th Annual Hydrometallurgical Meeting will be held in Vancouver from 18th to 22nd August, 1985. Light metals The 8th International Light Metals Congress will take place from the 22nd to 26th June, 1987. These meetings, which take place traditionally every few years, are organized by the Austrian Metals Industry Association, the Austrian aluminium industry, and the University for Mining and Metallurgy in Leoben, in collaboration with the Aluminium-Zentrale Diisseldorf. President of AS&TS* Mr Arthur Woodington Reynolds (Sam) took office as President of The Associated Scientific and Technical Societies of South Africa on 28th November, 1984. Sam Reynolds was born in Boksburg on 27th December, 1930, and received his education at Christian Brothers College in Boksburg and at St John's College in Johannesburg. World mining Sweden, Finland, and Norway expect representatives of all mining countries in May-June 1987 to the 13th World Mining Congress in Stockholm. The Swedish Mining Association, the Finnish Association of Mining and Metallurgical Engineers, and The Association of Norwegian Mines will organize the Congress, together with the International Organizing Committee of the World Mining Congress. Sheet metal The German Group of the International Deep Drawing Research Group (IDDRG) will be organizing the 14th Biennial Congress of the IDDRG on 21st to 26th April, 1986, in Cologne and Munich. Safety in mines The 21st International Conference of Safety in Mines Research Institutes is to be held in Sydney from 20th to 25th October, 1985. ILAF A conferences The Instituto Latinoamericano del Fierro y el Acero (ILAFA) has scheduled the following congresses for 1985. Mechanical testing of materials The Deutsche Gesellschaft fiir Metallkunde, together with the Deutschen Verband fiir Materialpriifung and the Fachhochschule Osnabriick, is holding a course on the methods used for the mechanical testing of materials at Osnabriick from 9th to 11th September, 1985. Mine ventilation The Second U.S. Mine Ventilation Symposium will be presented from 23rd to 25th September, 1985, in Reno, Nevada, by the University of Nevada-Reno's Mackay School of Mines and Division of Continuing Education.

Jan 1, 1985

The optimal design of production phases and ultimate pit limit for an open pit mining operation may be generated using conventional or stochastic approaches. Unlike the conventional approach, the stochastic framework accounts for expected variability and uncertainty in metal content by considering a set of equally probable realizations (models) of the orebody. This paper evaluates the performance of a new stochastic network flow approach for the development of optimal phase design and ultimate pit limit using a gold deposit as the case study. The stochastic and conventional frameworks as considered here utilize the maximum flow and Lerchs-Grossman (LG) algorithms, respectively. The LG algorithm is restricted to considering an estimated (average-type) orebody model, while the stochastic maximum flow algorithm is developed to simultaneously use a set of simulated orebody realizations as an input. The case study demonstrates that, when compared to the conventional LG algorithm as used in the industry, the stochastic approach generates a 30 per cent increase in discounted cash flow, a 21 per cent larger ultimate pit limit, and about 7 per cent more metal, while it maintains a consistency in phase size.

Jan 1, 2012