Search Documents

NOTICES The Institution of Mining and Metallurgy The Institution is to hold a one day meeting entitled "Sampling in the mineral and metallurgical processing industries" at Imperial College, London, on 2nd July, 1973. International Conference on Air Pollution This Conference is organised by the Department of Health and the National Association for clean air. Consas 74 The Fifth Conference of Southern African Surveyorswill be held in Salisbury, Rhodesia, from 3rd to 9th February, 1974.

By A. Morley

It is difficult to evaluate exploration properties in a manner that is transparent, repeatable and easily re-calculated to cater for different geological interpretations, but the risk-based assessment methodology, the Geological Risk Method, developed and described by Lord et al (2001) attempts to satisfy all these criteria. This paper examines a case study example based on valuations of exploration projects conducted by SRK Consulting using this methodology, and describes some of the advantages and limitations of the method.

Jan 1, 2007

Results from a study undertaken at a Transvaal colliery on the feasibility of undermining an urban development by conventional bord-and-pillar mining operations in the No. 4 Seam of the Highveld Coalfield are discussed. Surface ground vibrations above production sections were measured, analysed, and then compared with well-accepted guidelines so that the expected effects of vibration on inhabitants and surface structures could be determined. The measurement and scaling of ground vibration from blasting are outlined, and the effects on humans and structures are discussed. It is concluded that residential areas can be safely undermined by conventional drilling and blasting techniques provided certain simple guidelines are followed.

Jan 1, 1987

By J. D. Koch

The past ten years or so have seen many changes in the methods and approach adopted for projects in the metallurgical and mining industry in South Africa. These changes have led to an increased use by operating companies of the project and construction management services offered by engineering contracting companies. For a variety of reasons, this development has been slower in the metallurgical industry than in other areas of production, but that industry is also now showing an increasing trend in this direction.

Jan 1, 1981

By O. G. Pauw

The relationships between mill power and pebble load, bulk density of the load, and circulating load were investigated on the pebble mills in the grinding circuit at Buffelsfontein Gold Mine. This paper describes the most significant relationships among the operating and control variables on the plant, and illustrates these by reference to experimental data gathered from the plant during operation. The results were used for the development of very successful multivariable peak-seeking controllers for the pebble load and bulk density of the load on these pebble mills. The peak-seeking control algorithms are described in detail. The control system has operated successfully at Buffelsfontein for more than 18 months and is still in operation.

Jan 1, 1985

By J P. van Dyk

The dramatic strengthening of the rand against the dollar as well as a decline in quantity and quality of locally available concentrates have had a dramatic impact on Zincor?s operations during the previous two years. Zincor has responded with the implementation of a number of technical improvements to the process to decrease cost and increase revenue and plant flexibility. Among the initiatives is the pre-leaching and pelletising of the zinc concentrate, de-bottlenecking and process improvements in the leach and purification circuits, the introduction of cathode washing and automated cathode stacking in the cell house and the installation of a new furnace to produce pre-alloyed jumbos. This paper will describe these initiatives and others that Zincor have recently taken to stay competitive in changing global base metals market.

Jan 1, 2005

By D. J. Bosman

The impoved densification of sludge from neutralized acid mine drainage. by D. J. BOSMAN, B.Sc., (Member) The paper describes an investigation aimed at finding a solution to the accumulation of acid mine drainage in the old workings at Coronation Collieries, Kromdraai. The problem involved the neutralization of the acid in the water, without the large volumes of sludge and the large amounts of dissolved solids that usually result from neutralization. Pilot-plant work on the site using a limeneutralization process developed at Bethlehem Steel Corporation (U.S.A.) showed this to be a feasible method. A sludge of 22 per cent density was obtained under optimum operating parameters. The amount of suspended solids in the overflow water was very high, but this does not give rise to concern because the full-scale plant at Kromdraai will practise secondary sedimentation by running the thickener overflow through large dams with a theoretical retention time of 25 days. An analysis of the theory underlying the process is also made.

Jan 4, 1974

By C. S. Erasmus, L. C. Woollacott

The distribution of gold loaded onto carbon particles from a carbon-in-pulp operation was measured by neutron activation analysis. The nature of the distribution is examined, and the implications for operating plants and CIP simulators are discussed.

Jan 1, 1992

By D. M. Meyer, K. Auerswald

The production of electrolytic manganese in South Africa by M. HARRIS, Pr. Eng., B.Se. (Eng.) (Fellow), D. M. MEYER, Pr. Eng., B.Se. (Meeh. Eng.) (Visitor), and K. AUERSWALD (Visitor) The decision to construct the first electrolytic manganese plant in South Africa was important and farreaching. After evaluating the results of the pilot plant operation, the first South African producer, Electrolytic Metal Corporation (Emcor), established a plant in Krugersdorp. Initially, there were many process problems that had to be InvestIgated, and, after these had been solved and many operating parameters had been established, manganese was successfully produced. When the Delta Manganese plant in Nelspruit was planned, cognizance was taken of the fact that, if peak efficiencies were to be maintained, the process must be operated between fairly narrow parameters. Instrumentation was therefore installed to control the process automatically wherever possible. The main features of the Delta Manganese operation are outlined, with a brief description of each stage of the process from ore milling through to electrowinning and packing of the metal. It is concluded that much benefit can be obtained from further research work into process improvements and into the exact effect of certain variables on plant and current efficiency.

Jan 2, 1977

By H. M. Friede

A study was made of the smelting process in two experimental furnaces patterned on Iron Age furnaces excavated at Melville Koppies Nature Reserve, Johannesburg. In a number of smelting experiments, the influences of air supply, temperature, time of operation, fuel consumption, and other operational factors were investigated. Metallurgical and metallographic aspects of the furnace operation and smelting products are discussed, and the experiments are compared with similar research work conducted in Europe and Africa.

Jan 1, 1984

A modified germanium recovery process in conventional zinc metallurgy, based on the understanding that ferric hydroxide has strong ability to coprecipitate germanium element, was presented. The relaxed lab-scale experiments were conducted to evaluate its technological feasibility. The experimental results obtained show the new process has great competitive advantage over the conventional one.

Jan 1, 2008

By R. W. O. Kersten

The main objective of The South African Institute of Mining and Metalurgy is to identify the needs of the mineral and metals sector of the South African economy, and to initiate the means by which the requirements for technology and scientific knowledge can be satisfied. To achieve this, the Institute organizes schools to promote technology transfer and to satisfy the needs of its members for continuing education by the exchange of technical information, the communication of ideas, and the identification of technological problem areas.

Jan 1, 1986

By A. Cambitsis

We show that the prioritization of business improvement and performance management decisions may be significantly improved by taking into account the systemic effects of changes made in a single process area. To do so we build a model of a mining value chain, taking into account consequential downtime that arises from downstream and upstream starvation and choking effects of each activity. Introducing the concept of internal capacity, this approach yields insight into the relative importance of key metrics such as loading and hauling rates. We suggest that a holistic view of this type should be a core component of business improvement and performance management decisions. Keywords value driver trees, production constraints, throughput analysis, capacity analysis, TOC (Theory of Constraints), activity interdependencies, unit cost reduction.

Oct 1, 2013

By M. C. van Blerck

This paper reviews the current mining taxes in South Africa, discussing the recommendations of the Mantis Technical Committee, the measures already implemented, and the future outlook. It is concluded that the tax burden imposed on individuals and on the corporate sector should be reduced, and that the taxation of al economic sectors should be neutral. The reforms implemented in 1989 and 1990 are expected to continue, and it is thought that, if the State commits itself to tax neutrality and reduces the ordinary rate of company tax to 40 per cent, the rate of mining taxes will also be lower. Ring-fencing is expected to be reduced further and the rules for capital safe-havens to be refined.

Jan 1, 1990

The FSPE Award for Services to the Engineering Profession was awarded to Or Francis George Hill at a ceremony held in January of this year by the Federation of Societies of Professional Engineers. The following is an abridged version of the citation made by Professor A.N. Brown, President of FSPE, and of Or Hill?s reply. Achievements. It is indeed fitting that such a distinguished group of people have gathered on this special occasion to honour and pay tribute to Or Pinkey Hill

Jan 1, 1988

By L. Wade

Laboratory testing of the self-heating propensity of coal, using crossing-point temperature and differential thermal analysis techniques, involves the frequent recording of several temperatures. The volume of data and the desire for high accuracy of measurements motivates an automated recording system. The data which are recorded must be adjusted for calibration factors and the results presented in both graphical and tabular form. The paper describes hardware and software features of a computerised system which is being used to establish the relative propensity to self-heating of a wide variety of coals.

Jan 1, 1987

By SAIMM Journal

COLLOQUIUM ON COMMINUTION The Institute has arranged a colloquium on the above topic to be held on 13th March, 1973, at Kelvin House. The following papers will be presented: 'Peripheral Discharge Mill', by A. H. Mokken, Union Corporation Limited

Jan 1, 1974

By E. P. Gush

Diamonds, an enigma in a mineral resource sense. Chemically, diamonds are no more than carbon crystals in a cubic system-formed one might add under conditions of great pressure and temperature. They have certain physical properties which are fairly unique. They are very hard, they have a high refractive index, they luminesce, some of them fluoresce, they have a high specific gravity, they don't wet and they are a good conductor of heat. In a way, a rather clinical set of qualities. Of course, these qualities are what give diamonds their use and their beauty. It is on the emotional side that they get complex and stir memories of legends, of beauty, of wealth and romance, of war, happiness, bad luck and curses. It is on the emotional side that the value of a diamond is established, if such a thing is possible. Diamonds are extremely varied, there are more than 5000 categories into which they are sorted, so there is room at each point across the spectrum for their individualities to emerge, and accordingly their attractiveness to each buyer is unique.

Jan 1, 1994

From 19 November 1996, South African companies will be able to manage the impact their activities have on the environment in terms of international standards. The establishment of a registration scheme for environmental management systems was formally announced by the South African Bureau of Standards (SABS) (19 November 1996). At a function held at the SABS head office in Pretoria, Dr Jean du Plessis, President of the SABS, announced the launch of the SABS ISO 14001 registration scheme which is based upon ISO 14001, 'the internationally recognized yardstick for environmental management'.

Jan 1, 1997

The following are available from Metal Bulletin Books Ltd, Park House, Park Terrace, Worcester Park, Surrey KT4 7HY, England. . World aluminium-a Metal Bulletin databook. 2nd ed. 1990. £71.50 surface, £76.50 airmail. This is a compendium of information listing salient details of companies mining bauxite and producing alumina, primary aluminium, secondary ingot, master alloys, and semi-fabricated products; aluminium trading companies; and a memoranda section listing associations, brand names, and other useful information. It is a userfriendly international reference book for aluminium buyers, traders, and producers.

Jan 1, 1991