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By F. P. Greyling

The aspect of sustainability of ferroalloy processes has long been a serious matter for consideration in many of the world?s industrialized countries. A number of countries can be named where ferroalloy plants that were once flourishing, have all but disappeared. One of the most important factors playing a role in this type of occurrence is the cost and availability of quality raw materials. Given that all natural resources will be depleted with time, users are compelled to develop new processes that are sustainable in the changing environment. The DC arc smelting furnace is one such process that has proved itself, and has gained increasing popularity over the past two decades. This process, amongst other benefits, directly addresses the use of more readily available and more affordable raw materials in ferroalloy production. Since early in the new millennium, GLPS has been involved in various studies for different clients of furnaces for the production of ferroalloys. Two of these recent studies have culminated in the design, construction and commissioning of DC arc furnaces for the production of ferrochrome. One of these furnaces is a 10 MW unit at Mogale Alloys, and the other a 60 MW unit at the Middelburg plant of Samancor Chrome. This paper discusses the approach taken in the design and construction of these two furnaces, which, although varying significantly in size and capacity, are very similar in many other aspects of their design. Keywords Furnace, DC arc, and ferrochrome.

Jan 1, 2010

By D. Van Dyk

Horizontal rotating mills are being used all over the world in different mineral and power generation industries. David Brown South Africa, with over 140 years of experience in gear manufacture and design, has been supplying these industries with innovative designs at exceptional quality. The gearing systems associated with these industries are challenged daily with operating conditions that are not always fully understood. Failures are therefore experienced, over time in the industry, which cannot always be fully explained. David Brown South Africa has developed a gear monitoring system, the Intelligent Gearing System, in association with Transmission Dynamics (UK), in order to monitor and analyse these operating conditions in real time. The system has been designed on the principles of Six Sigma, incorporating Design for Six Sigma. The purpose with this system design is to monitor the operating conditions on the pinion, record the information and analyse the data in relation to the rate of fatigue damage to the girth gear and pinion. This is done in real time and unattended. The output from the Intelligent Gearing System can be fed back into the operating system of the mill user, in order to display an alarm for operating conditions exceeding the design criteria as well as information on the rate of fatigue damage due to these operating conditions. When the mill operating and the effect on the fatigue life of the mill gearing components, conditions are better understood, mill users can forecast critical spare holding levels with an increased accuracy. The Intelligent Gearing System also allows early actions to remove reasons for system overloads.

Jan 1, 2006

By G. T. Lineberry, C. M. Baird, D. L. Silverstein

The University of Kentucky (UK), with an enrollment of 25,891 in fall 2002, is a comprehensive, public land-grant university located in the Bluegrass Region of Central Kentucky. As the State’s flagship university, UK has long been involved in distance education, first through traditional correspondence courses, followed by use of videotape and satellite delivery in the 1970s and1980s, but soon supplanted by use of interactive television (ITV) and on-line course delivery in the 1990s to date. Today, UK Distance Learning Programs annually administers approximately600 course sections, with services provided to over 5200 enrollees. Courses are offered via six media: interactive video, Internet, on-site, satellite, open-air and cable television, and videotape, with hybrid delivery becoming increasingly popular. The University of Kentucky College of Engineering experience with distance instruction prior to 1985 was limited to videotape non-credit offerings. The Department of Mining Engineering, a small department in terms of numbers of both faculty and students, was a University pioneer in distance education. The first University degree program offered in its entirety by distance delivery(initially by itinerant faculty) was the Master of Mining Engineering. Satellite delivery from Lexington to Cumberland, Kentucky, was a welcomed change of delivery mode in 1987–88,resulting in six hours less travel time for faculty each week. Shortly thereafter, other initiatives directed toward fulfilment of its land-grant mission were undertaken by the College. Use of satellite for course delivery rapidly declined due to limited interactivity, in favour of compressed video and on-site instruction. Classroom sites in the Kentucky Tele-Linking Network (KTLN) now number over 200. The Network links schools, colleges and universities, as well as public and private agencies throughout the State. The KTLN supports voice, video, and data transmission in a uniformly-equipped environment. Beginning in the early 1990s, transfer-critical pre-engineering courses were delivered from Lexington to Kentucky’s community colleges with the largest pre-engineering enrolments. Success was limited, but lessons learned were invaluable. In 1996, the University of Kentucky College of Engineering was asked by the Kentucky Council on Higher Education (the predecessor to the Council on Postsecondary Education) to expand engineering education in Kentucky, first by initiating cooperative B.Sc. degree programmes in Chemical Engineering and Mechanical Engineering on the campus of Paducah Community College (PCC), located 400 km from the UK campus in Lexington. The third partner in these programmes is Murray State University (MuSU), a public regional comprehensive university 80 km south of Paducah. The genesis of the new degree programmes, which were subjected to ABET review in October 2002, as well as a summary of the major accomplishments and challenges of the innovative programmes, will be offered. The limited use of distance technologies for course delivery in these B.Sc. degree programmes will be discussed. A ‘no-spin’ overview of other non-traditional distance-learning ventures within the College of Engineering will be chronicled, with an honest assessment of the motivation for these efforts and, where appropriate, their relative degree of success. Among these ventures are: a BScME and a Master of Engineering programme at Toyota Motor Manufacturing of Kentucky, Georgetown, Kentucky; course exchange in Chemical Engineering between the University of Kentucky and the University of Louisville; an ITV-based Master of Engineering programme for practicing engineers in Kentucky; proposed joint-degree programmes in Civil Engineering and Mechanical Engineering with Western Kentucky University; and a proposed part-time MScME programme in Paducah, Kentucky, with a start date of August 2002, threshold enrolment permitting. Keywords: distance learning, distance education.

Jan 1, 2003

By Kedikilwe Oageng

Effective perimeter control during drilling and blasting is critical not only to blasting results but also to the overall stability of the pit over its entire life span. A pit where perimeter control is not given enough attention when conducting drilling and blasting operations, often experiences over-break or back break beyond final pit wall limits, and therefore has a relatively high probability of failure. Such a pit also becomes unsafe, sometimes not easily accessible, has increased loading costs due to production of oversize, longer cycle times and often problems are encountered when blasting subsequent benches. All these are undesirable consequences, which have negative cost implications. Specialised blasting techniques such as trim blasting and pre-splitting have over the years proved to be effective perimeter control measures. However, the success of these techniques is directly attributable to the time and effort given to the processes. This paper presents results of a project undertaken to monitor, review and optimize the trim blasting and pre-splitting processes at Orapa Diamond Mine in Botswana. The project was specifically incepted to improve the final wall conditions, which continued to deteriorate due to persistent over-break during blasting. The paper also analyses the results obtained against a benchmark of results taken prior to project implementation. Specific blast design parameters which are critical to blasting results were identified as problem areas after auditing of the pre-implementation drilling and blasting practices. These include drill-hole depth, spacing, splitting factor for pre-splits and timing of trim blasts. The impact of different rock types on the results was also studied, and recommendations were made at different phases of the project and results obtained after implementation analysed until optimum results were achieved.

Jan 1, 2008

By L. M. Tavares, T. M. Campos, P. M. Faria, R. M. Carvalho

Recent advances in mechanistic ball mill modelling are expected to allow for more accurate predictions that overcome the well-known limitations of phenomenological approaches, including their inability to predict the effect of liner geometry and their wear, in grinding. Although able to describe continuous operation, the UFRJ model of ball mills has only been validated in the past in mills that operate in batch mode, either in laboratory or pilot scale. The present work demonstrates the application of the mechanistic UFRJ ball mill model to predict fine grinding of iron ore in a pelletising plant in Brazil, the first application of such a mechanistic modelling in continuous mode. It shows that the model provides accurate descriptions of flows after iterations in a closed-circuit with hydrocyclones. Keywords: Ball mill, iron ore, grinding, modelling, particle breakage

Jan 1, 2020

"This study examines the problems faced by open pit mine superintendents who make choices about how to direct their materials, either to the waste dump or to the mill. The paper explores the effects of introducing a 10% sampling error and a 0.9-times to 1.1-times sampling bias on positively skewed distributions for precious and base metals, negatively skewed distributions in the case of bulk commodities, and normal distributions as is the case for coal deposits. Parent distributions for each commodity were created on a 25 x 25 m grid using transformations of gold, iron ore, and coal data-sets, spatially based on a nonconditional Gaussian simulation. Ordinary kriging of grades for the three commodities into a 10 x 10 m grid provided the reference case against which the distributions with the sampling error and sampling bias for the commodities were compared. Imposing cut-off grades on the actual-versus-estimated scatterplots of the three commodities allowed the distributions to be classified into components of waste, dilution, ore, and lost ore. Ordinary kriging of values for each deposit type acted as the reference data-set against which the effects and influence of 10% sampling error and 0.9-times to 1.1-times sampling bias are measured in each deposit type. Indications are that the influence of error and bias is not as significant in gold deposits as it is in iron ore and coal deposits, where the introduction of small amounts of error and bias can severely affect the deposit value.IntroductionThe effects of poor sampling and the financial implications for mining companies, traders in mineral assets, and sellers of metal as dore or commodities is documented in a number of studies, the most notable of which is that by Carasco (2004). He examined the financial impact of poor sampling practices in the Chilean copper industry and found that finacial losses due to poor sampling amounted to hundreds of millions of dollars over the life of a mining operation. Holmes (2004) examined the effects of correct sampling and measurement as the foundations of metallurgical balances, and found that revenues from the sales of large iron ore shipments may be profoundly affected by poor sampling practices. In South Africa the way in which sampling of in situ gold-bearing reefs affects the mine call factor has been an ongoing study since the disparity between the estimation of gold in the reef and the actual gold bullion produced was noted by early investigators such as Beringer (1938), Jackson (1946), Sichel (1947), Harrison (1952), and a number of others."

Jan 1, 2017

By H. J. Le Roux, W. B. Drummond

1. INTRODUCTION We have a moral responsibility towards the world to reduce the harmful deposits we emit into the environment arising from beneficiation technologies. Industry has not willingly spent money to limit these emissions because it affected their profit margin with the end result of emitting harmful elements into the environment. Governments have thus rightly stepped in and enforced systematic reduction of these emissions through legislation. In the past beneficiation of sulphur bearing ores was typically done through hydro-metallurgical concentration, smelting, followed by Sulphur removal by converting processes like the Pierce Smith converter. The latter two processes emitted substantial quantities of Sulphur into the atmosphere. Spiralling costs and legislation have resulted in the quest to develop more efficient and environmentally friendly processes to achieve the same end results. New hydro-metallurgical processes like the ActiVox process has completely eliminated the pyro-metallurgical processes. Kansanshi are also operating a similar process. It however elicits other ground water and spillage pollution hazards and problems of it?s own. Various improvements has also been made to the pyro-metallurgical stages, examples being combined smelting and converting with the Noranda reactor, the Codelco CMT furnace, one step flash smelting/converting or the Mitsubishi continuous smelting, converting and slag cleaning process. The new converting processes are also normally enhanced using oxygen leading to higher SO2 gas strength with only a marginal increase in off-gas volume. These processes have led to better efficiencies and a more controlled environment that reduces pollution, but does not eliminate it completely. The fact that there are still more than 70 existing Pierce Smith converter plants throughout the world that needs to be replaced or upgraded at tremendous capital cost, means that we will have the environmental problems for some time to come. The need thus exists to cost effectively get these existing plants into a state where they meet the new environmental regulations, community and safety requirements. This paper will concentrate on just one aspect of this quest, i.e. reduction/removal of off-gasses emanating from the converting of non ferrous sulphur mattes to achieve higher or specialised grades of refined metals.

Jan 1, 2005

By S. Khoshjavan

In this investigation, the effects of different coal chemical properties were studied to estimate the coal Hardgrove Grindability Index (HGI) values index. An artificial neural network (ANN) method for 300 data-sets was used for evaluating the HGI values. Ten input parameters were used, and the outputs of the models were compared in order to select the best model for this study. A threelayer ANN was found to be optimum with architecture of five neurons in each of the first and second hidden layers, and one neuron in the output layer. The correlation coefficients (R2) for the training and test data were 0.962 and 0.82 respectively. Sensitivity analysis showed that volatile material, carbon, hydrogen, Btu, nitrogen, and fixed carbon (all on a dry basis) have the greatest effect on HGI, and moisture, oxygen (dry), ash (dry), and total sulphur (dry) the least effect. Keywords coal chemical properties, Hardgrove Grindability Index, artificial neural network, back-propagation neural network.

Jun 1, 2013

The Barrick North Mara Mine and the Advanced Systems Group at SGS Minerals collaborated on the implementation of a grinding expert system for the control and optimisation of a single semi autogenous (SAG) mill. Over the last 5 years, grinding expert control has gained wide acceptance by mineral processors. In this paper, two key factors for success are highlighted: the adaptability of the software tools and the interaction with site personnel. Created with SGS?s MET expert console (MEC) toolkit, and running on Gensym?s G2 real time inference software, the North Mara expert logic has been set up to keep a steady and on spec leaching feed slurry while striving to maximize throughput. Leach feed stability was achieved by standardizing operating practices across shifts; a result of successful collaboration with site personnel in developing a consistent control strategy. The strategy maintains the SAG load and power draw in an optimised range by manipulating SAG feed rates and inlet water flow. The project life-cycle was slightly longer than average due to site specific constraints. One of these was the high turnover rate of site?s workforce during the project, coupled with the availability of key staff on site due to the fly in fly out work roster. These constraints called for different, and innovative ways of project commissioning and hand-over. This paper describes details of the control solution, its implementation as well as results and conclusions.

Jan 1, 2009

By G. Chitiyo

Prediction of pothole characteristics is a challenging task, confronting production geologists at the platinum mines of the Bushveld Complex. The frequency, distribution, size, shape, severity and relationship (FDS3R) of potholes has a huge impact on mine planning and scheduling, and consequently cost. It is with this in mind that this study was initiated. Quantitative analysis of potholes indicates that pothole size (area covered) can be described by two partly overlapping lognormal distributions. These are referred to as Populations A (smaller) and B (larger). The range of observed pothole sizes conforms to a simple double exponential growth model based on Newton's Cooling Curve. A third size range of very large potholes (Population C) that could not be modelled properly within the proposed growth model is interpreted as to represent a very early phase of aggressive regional thermo-chemical erosion and potholing. In general, potholes are dominantly quasi circular with only a subordinate tendency of elongation. In the UG2, potholes with elongated forms are more prevalent in the size range between 20 and 500 m diameter. In the Merensky Reef elongated potholes are more common in the size range above 50 m in diameter. Although not distinctly visible, elongation of potholes in both the UG2 and the Merensky Reef show a net north/south orientation. Using shapes of pothole rims and floor areas, documented for the UG2 in the Waterval Shaft area, it is demonstrated that the northern, down-dip edges of potholes have steeper dips than the southern, up-dip edges. Spatial distribution studies using a uniform quadrant method suggest that in both the UG2 and the Merensky Reef, the potholes are randomly distributed, with a tendency towards clustering. Clustering appears to be more prevalent in the smaller Population A potholes. Bearing all findings in mind, it is found that the model of thermo-chemical erosion of the cumulus floor by new influxes of superheated magma best explains the observed data. Partial to complete melting of the cumulate floor occurred in three phases. The first represents the emplacement of hot magma. This magma, due to turbulent flow and high chemical and physical potential, aggressively attacks the existing floor (crystal mush on the magma/floor interface). Regional erosion is manifested by large, often coalescing potholes. During the second phase, when the magma emplacement process ceased and cooling in situ started, two distinct periods of pothole formation ensued. The first is related to rapid cooling along the relatively steep part of the Newton Cooling Curve, when Population B potholes nucleated randomly and grew rapidly with concurrent convective overturn and largely laminar flow condition. The second period of cooling occurred on the shallow-dipping part of the Newton Cooling Curve. Population A pothole growth became more subdued and nucleation appears to have been, at least locally, clustered. The final phase of this proposed 'super magma cycle' was introduced when chromitite crystallization and precipitation terminated pothole formation. This was followed sequentially by pyroxene and plagioclase crystallization to form the typical cyclic units of the Critical Zone. No suitable proxy could be found for the prediction of pothole density of potholes associated with the UG2 (likely due to limited spatial data coverage), and these are best predicted by extrapolation. The Merensky Reef slope index, in contrast, provides a proxy for pothole density, enabling prediction with reasonable confidence. This predictive model has been verified using underground information. The findings made during the course of this investigation have, when implemented, significant impact. Successful implementation will not only allow enhanced resource and reserve definition, but also better mine planning and scheduling.

Jan 1, 2008

In China, thin coal seams are rich in resources but are technically challenging. The mineable reserves in these seams account for 20.4% of the total coal resources, while the current production accounts for only 10.4% of the total annual production. Characteristics such as narrow mining space, low level of mechanization, poor working environment, and high cost of mining, restrict the development of mining safety and efficiency. Recently, fully mechanized mining technology has developed rapidly for thin coal seams, the level of yield and efficiency has reached or exceeded the international standard, and some state-owned key coal mines are considering automation of their mining process. In thin coal seams with hard stone bands that contain concentrations of pyrite, a specialized software, LS-DYNA, is used to calculate the rational blasting parameters that are used in the deep-hole pre-splitting blasting. Using this method the hard stone bands are fractured effectively, and hence increasing the coal productivity. In addition, mining advance rate were increased by enhancing the level of fully mechanized equipment and safety improved by increasing gas drainage from the gas outburst prone seam located some 7 m below the coal horizon. At present, thin coal seam mining technology faces many challenges, including the low level of equipment automation, the low advance rate in mixed coal-rock ground, and the large number of the mine personnel underground. By lowering the labour intensity and improving efficiency through automation and other measures, more efficient working faces can be implemented in thin coal seams.

Jan 1, 2012

Grains are subject to contamination by mycotoxins which are metabolic by-products of various fungi. The fungal infestations produce local concentrations of the mycotoxins thousands of times higher than the average. These facts make the sampling of the grain for assessment of the mean mycotoxin levels potentially very difficult. In the context of sampling theory, this morphology of the infestations creates a very high distributional and intrinsic heterogeneity of the grain shipment. The distributions of mycotoxin concentrations in seaborne shipments that exist at loading and the number and intensity of infestations that develop under shipping conditions are unknown. All grain shipments carry spores that may give rise to mycotoxin-producing colonies; moisture and temperature determine the final extent of the problem. This paper develops the value of the sampling constant with respect to intrinsic heterogeneity based on data on observed Ochratoxin A (OTA) concentrations in individual wheat kernels. A useful relationship between the distribution of mycotoxin concentrations on a kernel to kernel basis and the distribution of concentration over subsamples is developed.

Jan 1, 2009

By J. Gholamnejad

Determination of the optimum production schedules over the life of a mine is a critical mechanism in open pit mine planning procedures. Long-term production scheduling is used to maximize the net present value of the project under technical, financial, and environmental constraints. Mathematical programming models are well suited for optimizing long-term production schedules of open pit mines. There are two approaches to solving long-term production problems: deterministic- and uncertainty- based approaches. Deterministic-based models are unable to deal with grade and geological uncertainties, which are two important sources of risk in mining industries. This may lead to discrepancies between actual production obtained by these algorithms and planning expectations. In this paper, a new binary integer programming model was developed for long-term production scheduling that incorporates geological uncertainty within the orebody. Then, traditional and uncertainty-based models are applied to an iron ore deposit. Results showed that the uncertainty-based approach yields more practical schedules than traditional approaches in terms of production targets.

Jan 1, 2012

By K. Lomberg

In this paper the process of sampling and assaying as it relates in particular to the platinum group elements (PGEs) is presented. A discussion of the geology of PGE deposits is included to provide an understanding of the mineralization that is considered necessary prior to sampling, as this has a direct bearing on the mineral resource estimate and also the selection of an appropriate mining cut. The discussion includes the selection of the sampling technique (drilling or face sampling), the size of the sample relating to the requirements of the laboratory, the potential mining cut, as well as a reference to sampling theory. The selection of an assay technique that is appropriate and will yield the optimal result based on sample turnaround, precision, accuracy, and cost is then considered. Examples are drawn from work undertaken on the Bushveld Complex (Merensky Reef, UG2 Chromitite Layer, Platreef) and Great Dyke (Main Sulphide Zone). A discussion of the appropriate QA/QC programme includes the chain of custody, CRM selection and the QA/QC process. Keywords sampling, assaying, QA/QC, platinum group elements.

Jan 1, 2014

By A. H. Mokken, G. K. I. Blendulf, G. J. C. Young

A study of the arrangements for pulp discharge on pebble mills, and their influence on mill performance by A. H. MOKKEN, B.Sc. (Eng.) (Rand) (Fellow), G. K. I. BLENDULF, M.Sc. (Stockholm) (Member), and G. J. C. YOUNG, B.Sc. (London) (Member) Although used for many years in the gold-mining industry, the conventional pan lifter at the discharge end of a pebble mill has hindered attempts at optimization of speed of rotation and pulp flow. A theoretical approach to flow patterns in pan lifters has pointed to limitations in the capacity of these lifters, with capacity decreasing as speed of rotation is increased. Complete elimination of the pan lifter by the adoption of peripheral or end discharge has resulted in a marked increase in pulp flow and an improvement in power utilization. Assays of the gold content of pulp discharged after a mill stoppage from mills fitted with pan lifters show values well in excess of the current milled grade, which indicates an accumulation of gold particles in the mill and, therefore, a longer retention period. The same could apply to other heavy minerals and metals present in the ore feed or worn off mill linings and metallic grinding media. Examples are osmiridium, fine iron and iron alloys, and copper and sulphide minerals. This phenomenon is attributed to the higher specific gravities of these metals and minerals, causing them to migrate towards the mill shell, from which position they are not readily removed by the lifters at the discharge end of the mill. The close association of gold particles with iron and sulphide minerals in the crevices of mill liners might be conducive to the formation of coatings on the gold. Assays of samples of milled pulp taken from a mill designed for end discharge show a lower accumulation of gold. The accumulation and nature of these gold particles are being studied at present. With increasing diameters of pebble (or autogenous) mills, peripheral or end discharge appears to be the preferred method of pulp removal.

Jan 5, 1975

If the Journal is to fulfill its mandate to the mining and metallurgical industry, it needs to expand its readership and, by implication, membership of The South African Institute of Mining and Metallurgy. This we hope to do by increasing the appeal of the Journal to a wider audience through the inclusion, in addition to our high-quality research papers, of equally high-quality papers, articles, and contributions that will be of interest to our less research-minded members.

Jan 1, 1990

1. Recent books D. K. Hsiao, D. S. Kerr, and S. E. Madnick. Computer security. New York, Academic Press, 1979.276 pp. $18. W. C. J. van Rensburg and S. Bambrick. Economics of the world's mineral industries. Isando, McGrawHill, 1979. R18,95. Soviet metallurgical research 1973-1977. Vo!. 1. Subject index and author index (1963-1972). Vo!. 2. Chronological listing of titles with full bibliographical information (1960-1972). London, Scientific Information Consultants Limited (661 Finchley Road, London NW2 2HN). £24 per set. W. Hoosen. Miners' dictionary. London, Institution of Mining and Metallurgy, 1979. (Reprint.) £11 (£9 for members). G. J. Pitt and G. R. Millward. Coal and modern coalprocessing: an introduction. New York, Academic Press, 1979. 224 pp. $18. D. Stephenson. Rockfill in hydraulic engineering. Amsterdam, Elsevier, 1979. 228 pp. U.S. $45, D.fl.90. 2. NIM reports Report no. 2015 The preparation of synthetic standards for use in instrumental neutron-activation analysis. Report no. 2029 The commissioning of a 5 kW inductively coupled plasma unit for use with a 3,4-metre Ebert spectrograph. Report no. 2032 The Cancer Project: a summary of the computer-aided operation of a 48 MV.A ferrochromium furnace. Report no. 2036 The determination of thallium in ores, concentrates, and metals. Report no. 2040 A solid-state constant-current power unit for the magnetic analyser of the MS702R mass spectrometer. Report no. 2044 The separation and determination of anions by ion chromatography. Computer congress In October 1980, Japan and Australia are hosting the 8th World Computer Congress. This Congress is a triennial event conducted under the sponsorship of the International Federation for Information Processing. INFACON 80 The Second International Ferro-Alloys Congress, organized by IPFEO (Institute of Western European Ferro-alloy Producers), is to be held in Lausanne, Switzerland, on 13th to 16th October, 1980.

Jan 1, 1980

By D. T. Williamson, B. P. Gilbertson

Satellite observation of mine-dump vegetation by B. P. GILBERTSON, M.Sc. (Phys.) (Visitor) and D. T. WILLlAMSON, B.A., LLB., B.A. Hons. (Visitor) NASA's first Earth Resources Technology Satellite (ERTS-I) was launched on 23rd July, 1972, and has subsequently gathered multispectral imagery of most of Southern Africa from an orbital altitude of 900 km. Images of the Witwaters rand area have been studied in an attempt to differentiate between mine dumps having varying degrees of vegetative cover. At this stage it is clear that the various mine dumps can be located and identified, and differences in vegetative cover can be seen and measured. Patterns of vegetative growth, some characteristic to particular dumps, can also be seen.

Jan 2, 1974

Prof C T O'Connor holds the degrees of BSc, BSc Hons, University of Cape Town (UCT), where he started his academic Lecturer in the Department of Physical Chemistry in 1976. Mr P Smith, educated in England and the former Southern Rhodesia, joined Gold Fields of South Africa in 1966 as a Metallurgical Learner Official. After obtaining a BSc Eng at the University of the Witwatersrand in 1972, he returned to Gold Fields. Mr P D K Robinson was born in Zimbabwe, and was educated at Dale College in Kingwilliamstown, matriculating in 1952. He holds a Mine Surveyor's Certificate obtained in 1961) and a Mine Manager's Certificate (obtained in 1966), as well as an EDP from the University of the Witwatersrand.

Jan 1, 1991

By S. Visage

By 1984 Iscor's first direct-reduction plant will be operating at the Vanderbijlpark Works, and for the fin;t time the Corporation will have an alternative method to the blast furnace for producing iron from ore. The performance of Iscor's four-kiln plant, which will be the largest coal-based plant in the world producing sponge iron, will undoubtedly be watched with great interest by steelmakers throughout the world. Beneficiation of tin The Southeast Asia Tin Research and Development (SEATRAD) Centre is a regional oganization, formed by the Governments of Indonesia, Malaysia, and Thailand with assistance from the United Nations, to conduct, coordinate, and promote research and training in the various fields of tin production, including geology, prospecting, mining, mineral processing, and smelting.

Jan 1, 1982