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While some of the practical details of ilmenite smelting are not well documented, there is a substantial body of literature on the principles of ilmenite smelting, and the behaviour of solidified titania slag. This information is summarized, focusing on the basic reactions, departure from equilibrium, the behaviour of impurities, and reactions of solidified slag. The emphasis is on the South African operations.

Jan 1, 2007

In the wake of the financial crisis that affected world markets in 2002, there has been an increasing international focus on corporate governance. Various corporate governance codes of practice have been introduced, such as the Sarbanes-Oxley legislation in the USA, the Combined Code in the UK, and King III in South Africa. This focus on corporate governance has increased since the most recent financial crisis in 2008, the effects of which are still being felt world-wide. In the mining and minerals industry, reliable metal accounting is essential to sound corporate governance and is also becoming a focus of increased attention and concern, particularly as the figures generated by the metal accounting system feed directly into the financial accounts of mining companies. Mass measurement, sampling, and analysis provide the input data for the metal accounting system and sound corporate governance requires that the procedures used are based on best practice and that the data generated is accurate and handled correctly, transparently, and consistently to produce the accounting reports. The AMIRA Code of Practice for Metal Accounting has been widely adopted in the industry as a means to achieve this, and the compilers of the Code have conducted numerous metal accounting audits at operations, both in South Africa and abroad. These audits have shown that there is a real need for such a code of practice. Keywords metal accounting, AMIRA Code, corporate governance, risk management.

Jan 1, 2014

By E. Minnaar, P. J. Cilliers, M. Bellino, L. M. Roux, R. Dye

The classic technique to remove impurities in a cobalt stream is selective precipitation. This is usually followed by re-leaching to produce an advanced electrolyte for cobalt electrowinning. Although this technique ensures an adequate cobalt concentration in the electrowinning circuit, some of the consequences include unwanted losses through the numerous selective precipitation steps resulting in lower recoveries. One plant that currently utilizes selective precipitation is the Luilu Metallurgical Plant (Luilu) in the Democratic Republic of the Congo. This paper evaluates the benefits of using solvent extraction technology as a purification step in the Luilu Process with the aim of further increasing the overall cobalt recovery and to ensure that a suitable cobalt concentration in the advanced electrolyte is achieved. The implementation of a solvent extraction-electrowinning process is found to be beneficial in terms of achieving improved recoveries and cobalt cathode quality, however there are many other factors that impact the success of converting from the classic precipitation process used at Luilu.

Jan 1, 2007

By S. Duma

The main sulphide zone (MSZ) of the Great Dyke is cryptic and without obvious stratigraphic markers. Although there are trends in the dimensions of the PGE and base metal profiles across the Hartley Complex, the profiles are invariant within a particular mining area. Ratios derived from these profiles are used to interpret diamond drill cores drilled ahead of underground development. Detailed logging of oriented core shows the exact position and attitude of intersected faults. Metal ratios are used to estimate fault throw to within 25 cm. It is possible to draw detailed sections showing the extent of ground disturbance well ahead of mining. The method has been confirmed by mining and by drilling inclined holes through the fault blocks. Keywords: main sulphide zone, Hartley Complex, Great Dyke, Zimbabwe, platinum, Palladium, Nickel.

Jan 1, 2004

By S. K. Lahiri, K. C. Ghanta

Design of industrial slurry pipelines is usually performed by applying semi-empirical procedures, requiring a significant experimental study for each project. The mechanisms of suspension flow are not yet completely understood and existing predictive models cover only some aspects of uniform or closely graded particle slurry flows. This paper presents a computational technique for prediction of the velocity and concentration profile in slurry pipelines based on computational fluid dynamics. This model gives numerical solutions for the concentration and velocity distributions in the pipeline cross-section. The model prediction and experimental concentration and velocity profiles were found to be in good agreement. Keywords: pressure drop; concentration profile; particle diffusivity; slurry flow.

Jan 1, 2007

By R. Haldenwang, R. Erasmus, P. T. Slatter, R. P. Chhabra

Notches are used routinely for measuring the flow rate of water with free surface flows. As far as can be ascertained, no work has been done to investigate the performance of these flow rate measurement devices for non-Newtonian suspensions. The Flow Process Research Centre at the Cape Peninsula University of Technology has investigated the flow rate of kaolin and bentonite suspensions from a tank for two notch shapes, namely rectangular and triangular, and for 3 different concentrations of each suspension. The notches were calibrated using water and then the kaolin and bentonite suspensions were tested in them. The rheological characterisation of the fluids was done with a Paar Physica MC-1 rotary viscometer fitted with a cup and roughened bob. Analysis of the results shows a significant increase in discharge coefficient with increase in concentration, and the discharge coefficient has been correlated to the yield stress. This is the first such study, and further investigation is needed to confirm and extend these findings.

Jan 1, 2007

By R. P. King

A class of gravity separation unit operations in ore-dressing relies for its operation on the production of a stratified bed. Heavier material gravitates downwards, and separation is achieved by splitting the ore horizontally, with the recovery of a dense stream and a lighter stream. The important ore-dressing unit operations that fall in this class are the jig, the Reichert cone and the pinched sluice. A new quantitative model based on Mayer's potential theory is developed here. This model is developed completely for the simple case of binary mono-size particulate materials, but the extension to units operating with feed material distributed over particle size and density is discussed in principle. The model can be used to predict the performance of these units and is very suitable for simulation. The model is tested successfully against experimental data obtained from a batch jig and a Reichert cone.

Jan 1, 1987

By D. G. Krige

The problem addressed is that of estimating grade differences between sub- divisions of a new gold mining prospect when only borehole results are available. Such differential grade estimates are required in choosing the best area for initial production, and in defining the grade profile over the mine's life for purposes of feasibility studies. It is also often necessary to differentiate between the grades and hence the values of subareas, owned by separate companies, for the purpose of fixing relative share participation percentages in the new mining company. It is shown that exaggerated grade differentials will be obtained from grade estimates of the subareas based only on boreholes within each such subarea, respectively, and that it would be more realistic to apply some 'smoothing', preferably by kriging. This is feasible because the lognormal-de Wijsian model can be used to give an indication of the spatial structure for the boreholes, even where they are spaced far apart; also the degree of 'smoothing' indicated is shown to be relatively insensitive to inaccurate estimates of the relevant semivariogram parameters.

Jan 1, 1987

By F. Reyes, M. Hilden, G. Forbes, M. Yahyaei

Since AlphaGo defeated the best human player in the game of Go in 2016 - something thought to be an impossible achievement - machine learning, deep learning and reinforcement learning have caught the attention of scientists, the media and the general public alike. This recent development in machine learning (let us remember that neural networks have been available for decades now) opens new possibilities in the areas of modelling and process control. However, little has been reported in the minerals processing industry about these new possibilities and opportunities. This paper presents and introduces the topic of reinforcement learning and the different platforms that allow its implementation. The paper shows the consequences of using reinforcement learning for the specific area of process control and optimisation. As an example, the authors present the use of reinforcement learning for the control of a SAG mill closed with a pebble crusher using industrial data from an operation. A comparison with advanced model-based process control is provided, showing the benefits and shortcomings of reinforcement learning as a new control and optimisation technique. Keywords: Reinforcement learning, deep learning, process control, process optimisation

Jan 1, 2020

THE BRITISH COUNCIL AWARDS 1971-1972 The British Council invites applications from permanent residents of the Republic of South Africa and South West Africa, for the following awards: SCHOLARSHIPS Scholarships are available to such permanent residents who hold university degrees or comparable professional qualifications. The scholarships are tenable for postgraduate study at universities and other educational establishments in Britain for the academic year of approximately ten months beginning 1st October, 1971. BURSARIES Bursaries are available to such permanent residents who hold university degrees or who, being already established in their professions or trades, hold other qualifications. The bursaries are tenable at British educational institutions or other suitable establishments in Britain for a course of training, study or research lasting not less than two months or more than six. The British Council may, at its discretion, bear the cost of single or return fares to Britain. The closing date for applications is 31st July, 1970. TRAVEL GRANTS Travel grants each of £300 are available in respect of journeys to Britain undertaken between 1st April, 1971 and 31st March, 1972 and are provided to facilitate visits to British universities by persons holding staff appointments or graduate research posts at South African universities. Visits must normally be of at least six months duration. The closing date for applications is 31st October, 1970. For further particulars and the relevant application forms please write stating the type of award for which you wish to apply to: The Cultural Attache, British Embassy, Pretoria. THE SECOND INTERNATIONAL CONFERENCE ON THE PROPERTIES OF LIQUID METALS Tokyo, September 1972 The Second International Conference on the Properties of Liquid Metals will be held under the auspices of The Japan Institute of Metals and The Physical Society of Japan from 3rd to 8th September, 1972 in Tokyo. The purpose of this conference is to continue and extend the efforts towards the objective of the First International Conference on the Properties of Liquid Metals at Brookhaven, 1966. The tentative Conference subjects presently planned are: Structure of Liquid Metals and Alloys; Atomic Transport Properties (Diffusion, Viscosity, etc.); Electronic States and Transport Properties; Thermodynamical Properties; Melting and Phase Transitions. Correspondence regarding the Conference and the request for the First Notice should be addressed to: Professor S. Takeuchi, Chairman of the Organizing Committee, The Research Institute for Iron, Steel and Other Metals, Tohoku University, Sendai, 980, Japan. PROCEEDINGS OF THE NINTH COMMONWEALTH MINING AND METALLURGICAL CONGRESS 1969 Volume 4 of the Proceedings of the Ninth Commonwealth Mining and Metallurgical Congress 1969- Physical and fabrication metallurgy-contains the 24 papers presented under this general heading at the Congress. Also included are discussion, authors' replies, name and subject indexes, and plenary addresses by Sir Val Duncan, O.B.E. and Sir Ronald L. Prain, O.B.E.

By P. G. Van Der Walt

This paper deals with the reticulation of deslimed tailings from surface to the stope face underground. Reference is made to the experience gained at the pilot plants operating on four of the gold mines administered by Gold Fields of South Africa, as well as at the full-scale system at East Driefontein which was commissioned recently. Mine-wide backfill systems are currently being installed on five other mines administered by Gold Fields. These six full-scale systems are capable of handling more than 270 000 tons of backfill solids per month. The type of reticulation system chosen, the selection of flowrates and the composition of the slurry, as well as the selection of the appropriate pipes and ancillary equipment are discussed. Both theoretical and practical aspects are taken into consideration. Other aspects covered include the design of underground storage dams and communication systems.

Jan 1, 1988

By K. F. Lane

Mine planning is a complex function and also a vital one. The quality of the planning has a profound effect on the efficiency and the economics of every mining operation. It is therefore important that the function should not be reliant upon only a few techniques but should have command of an orchestra of them. Then the most appropriate can be selected for each application or, if it is advantageous, a group can be employed in concert. This paper introduces peripheral algebra as a set of techniques which should be included in the mine planning orchestra. Its objective is primarily to stimulate more development not only of these techniques but also others of a similar kind which will increase the effectiveness of mine planning.

Jan 1, 1987

By B. Sergeant

Any study of the contentious subject of nationalization can ultimately be reduced to a sombre analysis of the simultaneous, and very different, interests of capital, labour, and government. Each of these interests attempts to maximize its objectives, subject to checks and balances provided, in an ideal system, by a country's executive government, legislature, and judiciary. Where even one of the three interests goes out of control, the consequences can be disastrous. The case histories show that when this occurs, the most common culprit is government, or its proxy, such as a dictator. At the other extreme, the case studies indicate that the optimum outcome occurs when capital, labour, and government are 'ring fenced' from each other: each enjoys its rights, but is also subject to duties. 'Conflicts of interest' between the three entities are ideally avoided to the maximum possible extent. The case studies include several salient instances from both the DRC (Gécamines, La Générale des Carrières et des Mines) and Zambia, along with Ghana and Chile. Further instances are examined in South Africa (gold), India (Coal of India), Brazil (Petrobras), Venezuela (Petróleos de Venezuela), Sweden (Luossavaara-Kiirunavaara Aktiebolag), Mauritania (Société Nationale Industrielle et Minière), Norway (Norsk Hydro), Botswana (Debswana), and Namibia (Namdeb). The article concludes broadly that South Africa's minerals sector is not ready for nationalization.

Jan 1, 2013

By J. Tikka, E. Bäcklund, N. -O. Lindfors

Tornados are the most violent weather events in the world, and we have all seen the forces and phenomena created by tornados in nature. Airgrinder AB has been working with a material treatment technology, which most easily could be described as an artificial tornado. The process consists principally of one air fan providing a high-velocity airstream that enters a mechanical cyclone. When the gas enters the cyclone, an outer vortex is created. This outer vortex rotates next to the cyclone wall, and at the bottom of the cyclone funnel the gas stream is turned and an inner vortex is created. The control of the air flow is tuned by a special device on top of the cyclone. The gas outlet is at the top of the cyclone and the material outlet at the bottom. The material is fed through a feeding device into the air stream channel prior to the inlet into the cyclone. The process is basically an improved grinding and dehydrating system, which is very efficient and environmentally friendly and can even be employed with very sticky materials. Also due to its rotating comminution, the material particles become rounded during grinding, hence more free flowing and easier to handle. MEFOS has already tested more than 30 different applications in the pilot equipment. The materials tested range from metallurgical slags containing 2?3% moisture to sludges with up to70% moisture. This technology has a potentially strong impact on mineral beneficiation, including the drying of sticky fine-grained materials, improved and selective gas scrubbing and the manufacture of free flowing powders.

Jan 1, 2007

P.W.D. ROSTER OF CONSULTING ENGINEERS (Extract from a letter from the Secretary for Public Works) In recent years a large number of professional engineers has entered the consulting field. Although the names of most of these have been placed on the Department's roster of consulting engineers either as a result of representations made by the South African Association of Consulting Engineers or by applying direct to the Department there are still some who seem to think that canvassing through an influential person is necessary to obtain commissions from the Department. The Department's roster is open to all registered professional engineers who are suitably experienced to undertake consulting work and commissions are awarded strictly on merit. I shall appreciate it, therefore, if registered professional engineers who wish to be considered for commissions by the Department could be advised that they must apply, in the first instance, to be placed on the Department's roster. On receipt of such an application a questionnaire listing all the information required by the Department will be forwarded to the applicants for completion and returning to the Department for record purposes. All names which appear on the roster are taken into account when a commission has to be awarded, due consideration being given to factors such as geographical position, seniority, capability and compatibility. AMERICAN SOCIETY OF MINING ENGINEERS 1970 FALL MEETING AND EXHIBIT The Secretary for Commerce has passed to us a letter received from the American Society of Mining Engineers, reading as follows: "We would be delighted to have South Africa attend our meeting next year and to exhibit some of their mining equipment in our Technological Information Exchange. The 1970 SME Fall Meeting and Exhibit will be held in St. Louis, Mo., October 21-23, 1970, at the Kiel Auditorium. The AIME WorId Conference on Lead & Zinc Mining and Metallurgy will be an integral part of our meeting-and an added incentive to attend. It should be understood that we discourage the showing of actual mining equipment and encourage the manufacturers and suppliers to send their engineers to man the booths. We hope that the exhibits will endeavour to put across their story by means of photographs, drawings, models and literature, rather than by display of prototypes of the actual equipment. We will be happy to welcome manufacturerers from South Africa as well as the mining engineers who, from time to time, have registered at our meetings." For further particulars, interested parties may write to the Society of Mining Engineers, 345 East 47th Street, New York, N.Y. 10077, D.S.A.

By Sh. Arshadnejad

Stress analysis in a rock medium is essential to determine the stress concentration between two consecutive circular holes and prediction of fracture behaviour. When two consecutive circular holes in a hard rock medium such as granite are loaded internally by the pressure of non-explosive expansion material (NEEM), stress concentration occurs between the holes which then causes the rock to fracture. In this work, finite element (FE) analysis using Phase2 code was employed to study the stress concentration between two consecutive circular holes under internal pressure induced by NEEM. Effects of different hole diameters and spacings, rock properties and NEEM pressures have been analysed. The data gained from the numerical analysis and analytical solutions were then used to develop two models. These models were then modified by using the FE data and polynomial regression analysis. The developed analytical models showed to be in a very good agreement with the FE analysis. Hence, the developed models can be used with confidence to determine stress distribution and concentration factors around two consecutive circular holes in a hard and brittle rock which are loaded internally by the pressure induced from the NEEM. Keywords Finite element method, non-explosive, quarry mining, stress concentration..

Jan 1, 2011

By M. Gholinejad

Applying non-explosive expansion material (NEEM) is one of the safest methods for rock fracturing, especially in a hard rock quarry. An experimental study was conducted to determine the pressure exerted by NEEM in a hole, which is necessary for analysing rock fracturing, particularly in a numerical modelling. Stress distribution was developed in a thick-wall cylinder in order to measure the tangential strain on the external boundary. In the experiments, nine pipes of different materials and varying diameters were selected and then loaded internally with a general type of NEEM. Through electrical strain gauges, the tangential strains were recorded on the external boundary of the pipes. The results obtained from these tests and existing data from previous researchers were utilized for the statistical analysis. A new experimentally-derived formula is proposed for determining the pressure exerted by NEEM by multiple parameter regression with a high correlation coefficient. The proposed model has a nonlinear form with three independent parameters i.e. the hole diameter, the time, and the modulus of elasticity of the material.

Jan 1, 2012

By Luis Rudolphy, Pekka Tähkiö

"Flotation plant design, construction and start-up can be challenging tasks, because multiple factors and disciplines have to be combined in an efficient manner, in order to execute a project that meets the technical, financial and timeframe expectations. Key considerations that need to be addressed when designing a flotation plant are process requirements, equipment integrability, automation, and up- and downstream processes/designs. Furthermore, several other lifecycle factors need to be considered, such as servicing and maintainability, operational costs, future expansions and decommissioning, among others. To address these challenges, Outotec has developed a new approach to designing flotation plants that targets eliminating most of the inherent risks that can be found in these types of projects. The new Outotec® plant is a fully modular approach in which the above-mentioned challenges have been taken into consideration in the design phase. As a result, the cPlant concept can give several benefits for new and experienced companies involved in the minerals processing business, such as lower risk investments, fast and cost-efficient flotation plant delivery, faster ramp-up period, easy plant expansions, fully automated processes and operation and maintenance ease. As well, dismantling and transportation of the cPlant to a new location is easy and fast, hence the new cPlant concept makes possible to exploit small, short-lifespan ore deposits and also retreat old tailings ponds that might contain valuable minerals and where the ore quantities are limited. Furthermore, cPlant is easily implemented for brownfields and temporary expansions during bigger expansions."

Jan 1, 2015

Rock fall accidents continue to be the main causes of fatalities in the mining industry. The occurrence of rock falls in supported stopes implies a failure of the support system. The failure of the support system in turn implies a failure in design. In this paper, ethical issues associated with engineering design are discussed, with particular relevance to stope support design. A risk approach is introduced that will allow designs to be carried out that are compatible with the acceptable risk defined by the mining company management. The implementation of this approach would overcome the ethical shortcomings of current support design practices.

Jan 1, 2007

By R. E. Phillips, L. A. Cramer, R. T. Jones

Atomaer (Pty) Ltd is a technology-driven company with interests in Western Australian nickel. Atomaer (RSA) Pty Ltd is a process technology company operating in Southern Africa. It is a subsidiary of Atomaer Holdings Pty Limited (Atomaer), which has operating companies in Australia, Africa, South America, and Europe. In addition, Atomaer has substantial shareholdings in Braemore Resources Plc, a nickel company with interests in sulphide nickel projects in Western Australia and Southern Africa listed on the Alternative Investment Market of London Stock Exchange (AIM); Mintails Limited, a gold company with interests in gold operations in South Africa listed on the Australia Stock Exchange; and Brinkley Mining Plc, a uranium company with interests in Southern Africa listed on the AIM. Independence Platinum Limited (IPt) has been formed by Atomaer to undertake the commercial development and exploitation of Mintek's ConRoast technology with the strategic objective of providing independent smelting and refining facilities with lower capital and operating costs for the treatment and processing of platinum concentrates, including those with high chrome and/or nickel and/or low platinum group metal values, for the development of platinum projects by junior resource companies in South Africa. The platinum mines of South Africa have traditionally exploited the Merensky Reef of the Bushveld Complex for platinum production. However, the mining of this reef is reaching depths that require significant vertical shaft systems and costly refrigeration for access to the ore bodies at deeper levels. In the past decade, all of the platinum producers have begun to mine the UG2 reef because of its cheaper mining costs. UG2 ore usually has lower platinum group metal contents and higher chrome values. The new junior resource companies have gained access primarily to UG2 reefs. Consequently, platinum mining is becoming more UG2-based and the resulting concentrates contain high levels of chromitite. UG2 concentrates are difficult to smelt in the current six-in-line submerged arc furnaces, and this leads to increased capital and operating costs for those smelting operations. The platinum mines of South Africa produce the majority of the world's platinum metal used in automotive catalysts and jewellery. As the platinum market is forecast to grow at a healthy rate into the future, the SA producers Anglo Platinum, Impala, Lonmin, and Northam are planning to expand mining operations in the next decade. Furthermore, a number of smaller new producers who are accessing other mineral resources are entering the buoyant market and will produce platinum concentrates for purchase or toll treatment. Hence, a shortage in both smelting and refining capacities is anticipated. Further smelting and refining facilities independent of the major platinum producers will be required in South Africa by 2010. Mintek's ConRoast technology is best suited to fill the need to treat a high proportion of UG2 concentrates in a cost-effective and technically efficient manner. Atomaer base metals technology has been developed for rapid leaching of nickel and other base metals from alloy. Significant reductions in capital and operating costs are expected from the combination of the two advances in process technology compared with that installed at the existing smelters and refineries that were established over 20 years ago. Independence Platinum will be listed on AIM and the Johannesburg Stock Exchange (JSE) in 2007, and developed as an independent, vertically-integrated platinum company using its independent smelting and base metals refining facilities as a strategic platform to promote the development and mining of platinum projects by junior resource companies in South Africa through technical co-operation, strategic alliances, joint ventures, off-take, toll-refining, and marketing agreements.

Jan 1, 2006