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By G. R. Marchant, B. K. Loveday

"A mathematical model has been developed for flotation circuit simulation. This model was designed to investigate the effect of varying the circulating loads and to determine whether an improvement in overall efficiency could be gained by a size separation prior to flotation.Model parameters were obtained by regression to plant data. Highly correlated parameters in the model were combined to reduce the number of parameters so that the need for excessive data gathering was eliminated. Mass balance smoothing was used to obtain a consistent data set for regression.The results of the simulation indicate that for the same grade of concentrate, an increase in copper recovery of 0.6 per cent may be Possible by increasing the circulating loads. The results of the simulation also indicated that recleaning of the plus 200-mesh material may be beneficiaL."

Jan 1, 2014

ADVANCES IN EXTRACTION METALLURGY AND REFINING A symposium organised by the Institution of Mining and Metallurgy will be held in London from 4th to 6th October, 1971. Particulars can be obtained from: The Secretary, Institution of Mining and Metallurgy, 44 Portland Place, London WIN 4BR, ENGLAND. ICAMC -71 - HUNGARY The Third International Conference on Automatic Control of Mines and Collieries will be held at Balantsfured, Hungary from 27th to 30th September, 1971. Further particulars can be obtained from: ICAMC - 71, Budapest 3, P.O. Box 115, HUNGARY. AUSTRALIAN INSTITUTE OF MINING AND METALLURGY Illawarra Branch A symposium on "Blast Furnace Injection" is to be held at Wollongong University College from 15th to 17th February, 1972. About 20 papers on various aspects of blast furnace injection will be presented, including two on nonferrous furnaces. Further particulars may be obtained from: N. Standish, Chairman, Symposium Committee, Wollongong University, Australia 2600.

By A. E. Landsberg, K. C. Corin, G. Stroebel, J. A. Miller, M. Becker, H. J. J. Gordon

Geometallurgy represents an integrated approach to mine planning and operation whereby the naturally occurring ore variability and its effects on all key downstream activities in the mine life cycle are considered. Process mineralogy is one of the key components of this integrated approach. This paper focuses on understanding some of the mineralogical variability across the Swartberg Cu-Pb-Zn sulfide ore in South Africa and its consequent effects on flotation performance. This process mineralogy project is motivated by the planned changeover and expansion of the Black Mountain Mines concentrator to process solely Swartberg ore compared to the run-of-mine blend currently being treated at the plant. Eight samples spanning the main lithological units of the ore body are described using quantitative mineral-textural data and bulk sulfide batch flotation performance to establish five process mineralogical or geometallurgical units comprising: quartz-pyroxmangite-magnetite, quartz-amphibolemagnetite, quartz-magnetite, garnet-magnetite-quartzite and mica-quartzite ores. Important mineralogical characteristics affecting Cu, Pb and Zn recovery, grade and selectivity specific to the different ore samples are discussed. Ultimately, the use of ore-specific process mineralogical and geometallurgical knowledge allows for better mine planning and plant optimisation. Keywords: Flotation, polymetallic base metal sulfide ore, process mineralogy, ore variability

Jan 1, 2020

By X. H. Li, Q. Zhang, X. Fei

Bauxite residue known as red mud (RM) is a by-product produced in massive quantities during alumina production by the Bayer process with a utilisation rate of less than 5%. A large amount of RM accumulated and produced continuously has had a seriously adverse impact on the surrounding ecological environment. The application of RM in building materials is considered to be the most effective and thorough way to make RM harmless and recycle resources for the reason that adding RM to concrete as a mineral admixture could not only consume a lot of RM, but also save cement and other energy-consuming industrial products. In this paper, the adaptability to cement and aggregate of RM was studied. The results showed that the compressive strength and flexural strength of concrete using ordinary Portland cement, slag Portland cement or fly ash Portland cement as cementing material showed different trends with the increase of the amount of RM. The influence rules of RM on the compressive strength of Portland cement, slag Portland cement and fly ash Portland cement concrete were similar, whether for silicate aggregate or carbonate aggregate. RM has a negative correlation to the flexural strength of silicate aggregate-ordinary Portland cement concrete, but a positive correlation to silicate aggregate-slag Portland cement, silicate aggregate-fly ash Portland Cement. RM promoted the formation of calcium carbonate crystals and inhibited the formation of ettringite and calcium hydroxide crystals in the matrix while ordinary Portland cement, Portland cement and fly ash Portland cement were used as cementing materials. This study provided support for the use of RM in concrete, the reduction of solid waste storage, and the saving of high energy consumption cement as well. Keywords: Red mud, cement, aggregate, adaptability, mechanical properties, mineral composition

Jan 1, 2020

By M. Mpofu, M. van Schoor, T. Kgarume, H. Grobler

The South African mining industry has committed to achieving a state of zero harm for its workforce, with a strong emphasis on worker health and safety. Among the major safety concerns are falls of ground, a leading cause of injuries and fatalities. Ground-penetrating radar, a non-destructive geophysical method, is recognised for its ability to image structures, fractures, and geological features within the rock mass. However, ground penetrating radar data is often acquired in local coordinates, posing challenges for visualisation in mine computer-aided design or three-dimensional visualisation software. This study explores the pivotal role of light detection and ranging data in transforming ground penetrating radar data from local survey coordinates to absolute mine coordinates. A comprehensive georeferencing methodology is presented, providing the stepwise progression from the initial georeferencing of ground penetrating radar data to the ultimate integration of ground penetrating radar and light detection and ranging datasets, resulting in the creation of a ground penetrating radar-light detection and ranging three-dimensional model. The proposed approach not only facilitates the integration of but also offers a practical means of visualising the integrated datasets within commonly used computer-aided design or three-dimensional visualisation software. An essential aspect of this integration is the adoption of non-proprietary data formats, specifically American Standard Code for Information Interchange text files, ensuring broader accessibility and compatibility. The potential for integrating diverse datasets to construct insightful models of the underground mining environment is illustrated. Integration of different datasets has the potential to offer a holistic understanding of the mining environment, providing essential information to decision-makers.

Jul 23, 2025

By Dick Minnitt

Large-scale variability in process plants and process control can be identified and controlled through disaggregating the overall variability in a process stream. Conventional statistics and Statistical Process Control (SPC) fail to address the concept of stream heterogeneity, therefore fail to identify and distinguish between the various sources of variability in a process stream. A modified set of 445 data from a process plant is used as an example to explain the benefits of variography in process control. Large-scale variability, usually in the form of product composition cycles and chemical cyclic variations may be manifest throughout a sampling system or a process plant, but this type of variability is most easily discernable in one-dimensional process streams. The Moving Average is a powerful tool for identifying large and small scale variability and cyclical behaviour in process streams, while the variogram is a custom built tool that allows the components of variability to be identified and resolved. The positions in the variogram at which the different variance can be read and the nomenclature of these types of variability is described. The transfer of variances converted to standard deviations to the Control Charts, allows an operator to appreciate the appropriateness of Upper and Lower control and specification limits. The overall contribution of the various sources of variability is represented in a pie diagram.

Jan 1, 2007

Professor H.R. Philips was born in South Wales. After graduating with a B.Sc. degree in electrical engineering from the University of Bristol, he joined the National Coal Board's management training programme. Mr B. Moore was born in Coventry, England. He matriculated at Bablake School and then atended Birmingham University, obtaining a B.Sc. Mining Engineering degree in 1953. Professor J .S.J. (J annie) van Deventer matriculated at Swelendam High School. He studied chemical engineering at the University of Stelenbosch, and obtained the degrees of Hons. B. Ing. in 1978 and Ph.D. (Ing.) in 1985. Professor M.D. Brayshaw received most of his education in England but obtained his Ph.D. (Eng.) at the University of Natal. Rock fragmentation by blasting The Third International Symposium of Rock Fragmentation by Blasting will be held in Brisbane, Australia, from 26th to 31st August, 1990. The Third International Symposium of Rock Fragmentation by Blasting is designed to inform delegates on the state of the art in explosives and blasting technology, and to build on the standards of excellence set by the previous symposia in Lulea, Sweden (1983) and Keystone, Colorado (1987). Delegates with an operational, technical, or research focus on blasting will gain from this interactive symposium. Recent journal Mineral resources engineering, edited by C. T. Shaw, T.L. Car, and M. Karmis. London, Taylor & Francis, 1989. Published quarterly. US $107 per year. Risk management The Cost Engineering Association of Southern Africa (CEASA) is to hold its 3rd Biennial Symposium at Indaba, Midrand, on 25th and 26th January 1990. The title of the Symposium is Risk Management in Promotion of Capital Projects. The present political and economic environment in South Africa is characterized by a lack of financial resources, and of technical and management skills, on the part of project owners, designers, and contractors/ vendors.

Jan 1, 1989

By A. Dienenthal

"The casthouse floor has always been one of the most dangerous working places on a blast furnace or a ferro-alloy/nonferrous furnace. Apart from working in an atmosphere including toxic gases, fumes, and dust, the workers have to perform hard and heavy manual work close to runners and ladles filled with hot liquid metal and slag.Before the invention and installation of tapping equipment the tap-holes were opened and closed manually. Opening was done by means of steel bars and sledgehammers, whereas the tap-hole was closed by repeatedly ramming small amounts of clay or refractory material into the tap-hole, again with the help of long, heavy bars. In addition, on blast furnaces the blast had to be stopped, since it was impossible to close the tap-hole properly against the blast furnace pressure. This stoppage of the blast resulted in regular losses of production. Around 1900 a major change in technology occurred. Samuel W. Vaughen, superintendent of the blast furnace department of the Cambria Iron company at Johnstown, Pennsylvania (USA), invented the first clay gun in 1895 (Wiley, 1896) (Figure 1)."

Jan 1, 2014

By Jannie Maree, Dieks Theron, Ryneth Nengovhela, Patrick Hlabela

In extracting base metals from ore bodies, sulphide as well as oxide, the main environmental concern is sulphur, whether in the form of sulphurous gases or sulphate in liquid form. Generally sulphur is in over supply in developed countries mainly because of strict legislation to capture it. In developing countries on the other hand there is usually a shortage of sulphur because of less strict environmental legislation. Africa falls in this second category and the African continent imports substantial amounts of sulphur despite the fact that large quantities of sulphur is emitted by smelters, thermal power stations, coal mines, fertilizer manufacturers and others. Other than making acid from gaseous emissions, existing methods to capture sulphur from gaseous and liquid effluents are uneconomical and it ends up in the environment either as ammonium sulphate (from gaseous effluents) or as gypsum (from liquid effluents). The CSIR?s Environmentek and Pyroserv has developed a process whereby gaseous sulphur emissions and sulphates in liquid effluents can be economically captured and converted into elemental sulphur and metal carbonates. The elemental sulphur is of high purity as it is precipitated from a gas stream and is readily marketable. The metal carbonates (barium or calcium) can be recycled back to the process or marketed. The only harmful byproduct of the process is carbon dioxide. Should natural gas or methane be available the carbon dioxide could be reduced by about one third. Should solar, wind or hydro energy be available to generate hydrogen the carbon dioxide emissions would be zero. Employing this technology could make Africa independent of sulphur imports and furthermore reduce the impact of acid rain and seepage of sulfate from gypsum and other waste dumps into the environment.

Jan 1, 2005

By G. T. van Rooyen

The susceptibility of a low-alloy steel that has been hardened and tempered-826 M40 (EN26)-to embrittlement by strain aging during service was simulated by artificial aging of specimens at 100°C. It was found that the brittle transition temperature of both monotonic and cyclically strained material was increased by only about 25°C as a result of strain aging. It is concluded that the susceptibility of low-alloy steels in the hardened, tempered condition is less than that of low-carbon steel, and that such steels qualify for exemption of the periodic 'annealing' required by the Mines and Works Act.

Jan 1, 1986

By A. Navarra, A. Quelopana

The mine production scheduling problem (MPSP) has been studied since the 1960s, and remains an active area of computational research. In extending the concepts of the MPSP, the automated mine may now be regarded as a hierarchical intelligent agent in which the bottom layer consists of distributed robotic equipment, while strategic functionality occupies the higher layers. Here we present a disambiguation of artificial intelligence, machine learning, computational optimization, and automation within the mining context. Specifically, the Q-learning algorithm has been adapted to generate the initial solutions for a high-performing strategic mine planning algorithm, originally developed by Lamghari, Dimitrakopoulos and Ferland, based on the variable neighbourhood descent (VND) metaheuristic. The hierarchical intelligent agent is presented as an integrative conceptual platform, defining the interaction between our new Q-learning adaptation and Lamghari’s VND, and potentially other hierarchically controlled components of an artificially intelligent mine, having various degrees of automation. Sample computations involving Q-learning and VND are presented.

Dec 1, 2021

By X. M. Prévost

The reassessment of coal reserves has become a matter of urgency and has come as a result of the present situation of the industry, in the context of globalized coal economies, as well as new mining legislation and the advantages and difficulties of domestic coal suppliers. The de Jager report concerning coal reserves, released twenty years ago, can no longer be used as an estimate for accurately forecasting South Africa’s future coal production. The new reserve and resource study will promote the diversification of energy sources and provide a clearer view of the future of coal mining in the country. With plans to increase South Africa’s coal export capacity to approximately 84 million tons by 2005, it is uncertain whether the country really has sufficient reserves to meet this expansion, as well as satisfy the projected increase in inland demand. The face of South Africa’s coal industry and by association, the economy of our coal-dependent country, are both set to change. This is mainly due to factors such as the demise of most of the large collieries over the last approximately twenty years, growing numbers of economic empowerment producers, the emergence of strong competition in the export market, the dawn of Clean Coal Technologies (CCTs) and the Kyoto Protocol The paper will attempt to dispel some of the current myths about coalfields and reserves and highlight potential areas of high quality coal reserves, available mainly to new entrants in the industry. Keywords: Central Basin, Clean coal technologies, Coal combustion, Coal exports, Coalfields, coalLink, Coal reserves, Coal resources, Coal processing, Colliery, Economic empowerment, Discards, Fluidized bed combustion, Low-ash coal, Metallurgical coal, Power generation, Pulverized fuel, Reserve blocks, Richards Bay Coal Terminal, Run-of-mine production, Saleable production, SAMREC Code, South Dunes Coal Terminal, Steam coal, Synthetic fuels.

Jan 1, 2003

By D. O’Beirne

Union Corporation are experimenting with a high-pressure water jet to remove blasted rock from short panels. The advantages are that the jet provides a highly efficient, flexible, and mobile cleaning tool that eliminates much of the lashing. Cost estimates show it to compare favourably with the existing system, with potential savings of 30 cents per ton milled. Equipment and method trials are continuing with the ultimate objective of eliminating hand lashing entirely while retaining the flexibility of the present method of mining.

Jan 1, 1979

By J. W. de Kock

The estimation of some properties of South African coals from proximate analyses by J. W. de KOCK, Pr. Eng., Ph.D. (Chem. Eng.) Cantab. (Fellow) and J-P. FRANZIDIS, B.Sc. (Chem. Eng.) (Visitor) Correlations have been obtained whereby calorific values, ultimate analyses, and Hardgrove Indices can be estimated from proximate analyses of South African coals. This has been done by the application of stepwise multiple linear-regression analyses of a mass of data published by the Fuel Research Institute.

By J. D. Koch

A 'project' is defined here as a process in which an idea is developed from its inception until either it is discarded or the product of the idea has been accepted by the ultimate user. The phases in a project, particularly the early phases, are examined, and project organization is described and contrasted with a functional line-management type of organization. Emphasis is placed on comprehensive definition, which is vitally important to the achievement of the goals of time, cost, and quality set for a project.

Jan 1, 1981

By P. J. Barton, N. F. Peverett

A brief review of the development and ultimate design of the Model 16 Photometric Sorter is given, including the differences between it and its predecessor, the Model 13, which is currently in operation at Doornfontein. A description of the West Driefontein sorting plant is given, together with the rationale of its design. The installation programme for the sorters is described, and current operating and maintenance procedures are discussed. Operating results are tabulated and compared with the original test results. Operating costs are also discussed.

Jan 1, 1980

By Marek Dworzanowski

Dense medium separation (DMS) is critical to the operation of coal and diamond beneficiation plants. It is also utilised in iron ore, manganese, chromite and andalusite beneficiation as well as pre-concentration for platinum-bearing UG2 ore. Gravity concentration plays an important role in the processing of diamonds, coal, gold, platinum, titanium minerals, zircon, chromite, iron ore and manganese. The DMS and Gravity Concentration operations and technology in South Africa conference will focus on the operation of DMS and Gravity Concentration circuits in the South African Mining Industry. The current status of the technologies and equipment employed will be presented as well as future developments. The conference was set up to showcase South African DMS and Gravity Concentration operations and provide a forum where operators, technology and equipment suppliers can engage in knowledge sharing. The papers cover a wide spectrum of topics, including descriptions of operations, optimisation projects, new capital projects, equipment applications, process monitoring and process selection. Most commodities and unit processes associated with DMS and Gravity Concentration are covered. The conference venue was selected to be the CSIR Convention Centre in Pretoria. The CSIR has contributed to DMS research in South Africa and it is located not far from many coal, diamond, gold, platinum and chrome mines that extensively utilise DMS and Gravity Concentration in their beneficiation plants. I believe that the papers and presentations submitted for this conference will provide a valuable future reference for DMS and Gravity Concentration, thus making the work of all the contributors to this conference highly rewarding and worthwhile.

Jan 1, 2006

This paper sets out to consider a specific type of corrosion protection system, which is referred to as a Duplex Coating system. The dictionary describes a duplex system as consisting of two elements or a “twofold” composition. The duplex system described in this presentation is such a two-part corrosion protection coating, viz, hot dip galvanizing as the firm base or primer, followed by a top paint system designed to combat severe corrosive environmental conditions encountered in nature. In principle, the duplex system is a cost effective and balanced, designed coating that is suited to the environmental conditions and service life requirements.

Jan 1, 2009

By N. Wagner, P. den Hoed, J. D. Steenkamp, S. Soqinase

In pyrometallurgical processes, metal oxides are reduced from molten slag through carbothermic reduction. It is of interest to evaluate the reactivity of the carbonaceous materials towards substances such as slag. Characterization techniques such as coal petrography can provide insight into the influence of feed coal properties and how they potentially dictate reductant performance. This study aimed to compare the petrographically determined organic composition of coal to reductant reactivity. Two South African medium-rank C bituminous coals and one anthracite sample were investigated together with high-carbon ferromanganese industrial slag. The reductant reactivity tests were conducted at 1500°C in a muffle furnace to assess the potential of carbonaceous reductant in reacting with the main slag components. SEM-EDS was applied to understand the extent of MnO (and to a lesser extent, SiO2) reduction from the slag. Coal 2, consisting of a greater proportion of vitrinite (59.5 vol% on a mineral matter-free basis and 54.7 vol% including mineral matter) was the most reactive reductant. The anthracite sample, with the highest inert maceral proportions (71.8 vol% including mineral matter and 76.8 vol% on a mineral matter-free basis), was the least reactive reductant.

Feb 6, 2023

By J. J. Cilliers, J-A. Lamamy, J. N. Rasera, K. Hadler

Production of oxygen on the moon can be achieved by reduction of lunar soil. One such reduction technology, hydrogen reduction, favours a high proportion of ilmenite in the feedstock. Ilmenite is present in lunar soil as a minor mineral phase, but it can be upgraded using electrostatic separation. This study presents the results of a preliminary investigation into the operating parameters and sensitivities of a free-fall electrostatic mineral separator for lunar applications. Samples of ballotini and ilmenite as well as simple binary mixtures of the two were tribocharged on copper and passed through a uniform electrostatic field. The field is varied to change the electrostatic force acting on the particles. The proportion of material reporting to the positive electrode collectors, negative electrode collectors or the central collector was measured to determine the separation performance. The data confirmed that the charge transferred from the tribocharger to each species is in agreement with the triboelectric series; ballotini was found to charge positively on copper and ilmenite negatively. Particle-particle contacts were dominant, however, resulting in a somewhat symmetrical particle distribution in the collectors. These findings indicate that the copper tribocharger design requires optimisation in order to substantially increase particle-wall contacts. Four binary mixtures with feed grades of ilmenite ranging from 5% to 20% were prepared and tested. This study found that a higher ilmenite head grade resulted in a higher concentrate grade (26.3% from a head grade of 20%) with low recovery (3.4%). In contrast, the lower feed grade resulted in a low concentrate grade but higher recovery. The mass yield of ilmenite was 1.4 times greater for the highest-grade feed than for the lowest. A subsequent study into the reprocessing of middling fraction found a nearly constant relationship between cumulative grade and recovery. This is the first investigation into the effect of feed grade on the concentrate grade and recovery for lunar mineral processing. Keywords: Lunar resources, beneficiation, electrostatic, SRU, ISRU

Jan 1, 2020