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By H. W. Glen

The National Institute for Metallurgy - usually referred to as NIM - has become the Council for Mineral Technology, or Mintek. The Honourable F. W. de Klerk, Minister of Mineral and Energy Affairs, announced the change of name at the official opening of the main entrance to Mintek's premises on 30th October, 1981. Awards for bravery Two men who disregarded the dangers of fiercely burning timber and falling rocks to douse an underground fire, using their hard hats to scoop water from a drain, received the Chamber of Mines Award for bravery at a ceremony held at West Driefontein Gold Mine near the end of October.

Jan 1, 1981

By John Freer

On 25th November, 1983, nearly forty members of The South African Institute of Mining and Metallurgy, together with Doris Gardner and Judith Money from Kelvin House, travelled by luxury motor coach to Secunda, there to visit the coal-mining and conversion operations of Sasol Limited.

Jan 1, 1984

By J. Rabe

Tasked with developing a flow sheet for a new resource, one typically turns the experts for help. The advice of an expert can be invaluable in reducing the time and costs associated with characterizing an ore (not to mention extracting maximum information from limited samples). While guiding and optimizing a metallurgical concept study requires a certain skill set, selling a project is something different. The metallurgical specialist is usually not responsible for sharing the results of investigations with potential investors. However, the person responsible for selling the project can ensure that a metallurgical concept study is conducted thoroughly and responsibly without having the ability to do the work, while being sufficiently familiar with the metallurgical aspects to authoritatively sell the project. The process of identifying suitable process routes through to constructing a concept flow sheet and mass balance is discussed as a basic example. From basic mineralogical information and a thorough literature survey, the most likely beneficiation routes can be identified and targeted testing conducted. The final top size will depend on the required product properties (mainly grade), the selected beneficiation technology, and the ore?s liberation properties. Once the required top size has been identified, comminution options can be evaluated. Once again, literature surveys can be used to supplement concept-level comminution property information, and select possible equipment and circuit configurations. Marketing, material handling, and logistics-related information can be used to determine required dewatering technologies. At this stage, enough information is available to develop a concept mass balance and conduct basic equipment sizing..

Jan 1, 2014

By JOURNAL SAIMM

SYMPOSIUM ON PELLETS AND GRANULES During October 1974, the Newcastle branch of the Australasian Institute of Mining and Metallurgy is to hold a symposium on pelletizing and granulation, with particular reference to the iron ore, fertilizer, and cement industries.

Jan 12, 1973

By G. Pienaar

The South African Institute of Mining and Metallurgy held a Colloquium on High-strength Low-alloy Steels on 27th October, 1983, at the Vaal Triangle Technikon, Vanderbijlpark. The Colloquium was attended by some 170 delegates.

Jan 1, 1984

By N. Reddy

The influence of local geology and rock mass characteristics on deformations during a rockburst caused by a controlled blast was studied. This was done by means of visual examination, mapping and photography both before and after the blast. We found that the ejected material was bounded mostly by fractures associated with the bow-wave fracturing and bedding surfaces and that existed prior to the blast. Most of the damage was caused by shake-out. This information is important input for the design of rockburst resistant support systems under conditions of moderate stress.

Jan 1, 2001

By J. Whitford

The established crown pillar extraction method at Gold Fields Australia Ltd.’s Crusader Mine, leads to the significant dilution and poor recovery of ore due to caving of the overlying loose rockfill. The application of selectively injecting specifically developed ‘FB200’ ettringite (calcium sulphoaluminate hydrate) type cement grout into loose rockfill to form a stabilised rockfill material, enables an artificial crown pillar to stabilise the surrounding rock mass and prevent caving of the overlying loose rockfill during crown pillar extraction. Investigation of the geomechanical criteria for crown pillar extraction beneath stabilised rockfill has enabled the safe and efficient extraction of two crown pillars at the Crusader Mine. La méthode actuelle d'extraction des piliers horizontaux à la mine Crusader dont la propriétaire est le Goldfields Australia Ltd amène à une dilution sensible du minerai, à cause de l'effondrement du remblai peu compacté qui se trouve au-dessus. Par moyen d'injection sélective du coulis de ciment FB200 ettringite (sulfoaluminate de calcium hydraté) qui a été développé spécifiquement pour cette application, un pilier artificiel est crée et celui-ci empêche l'effondrement du remblai pendant l'extraction du pilier de minerai au-dessous. A la suite des études géotechniques de la méthode, deux piliers horizontaux à la mine Crusader ont été extraites, de manière efficace et sûr. Die feststehende Krone Pfeiler Extraktionsmethode beim Crusader Mine von Gold Fields Australien GmbH, führt wegen caving des overlying lockerer rockfill zur bedeutungsvollen Verdünnung und schlechtem Wiederfinden des Erzes. Der Antrag, ausdrücklich entwickelten 'FB200' ettringite selektiv zu spritzen, (Kalzium-sulphoaluminate-Hydrat) Art kittet Mörtelschlamm in lockeren rockfill, um ein stabilisiertes rockfill-Material zu bilden, ermöglicht einem künstlichen Kronenpfeiler, die umliegende Steinmasse zu stabilisieren und caving des overlying während des Kronenpfeilerherausziehens lockeren rockfill zu verhindern. Untersuchung der geomechanical-Kriterien für Kronenpfeilerherausziehen unter stabilisiertem rockfill hat dem sicheren und tüchtigen Herausziehen von zwei Kronenpfeilern beim Crusader Mine ermöglicht.

Jan 1, 2003

By M. Ksiazek

Keywords: Thermal conductivity, thermal diffusivity, flash method, specific heat capacity, manganese ore Manganese ferro-alloys manufacturing involves a combination of quality raw materials and an energy source to produce high-quality products with low energy consumption. The thermal properties of manganese raw materials such as ores, sinters, and briquettes, are among the many factors that determine the amount of energy needed for processing. Thermal expansion, thermal diffusivity, conductivity, and apparent specific heat capacity of solid samples and compacted powder samples of manganese ores were examined from room temperature to 1000 °C. The effect of porosity (of the materials used) on the thermal properties was also investigated. The laser flash method and a pushrod dilatometer were used.

Jan 1, 2011

By J. Little

It is common practice for underground mine plans to be created sequentially, where results from one planning process form the input data for another. While this is practical for manual methods, computerized optimization techniques should consider an integrated approach to creating the global mine plan. This is because optimizing an individual mine planning process, such as stope layouts, introduces a likelihood of increasing costs or decreasing revenues associated with other areas, such as production scheduling, as harmful decisions must be balanced. Considering the interaction and influence that individual underground mine planning processes have on each other during optimization will provide more profitable results than if these are ignored. Optimization techniques for stope layouts and production scheduling are reviewed. An integer programming model is proposed that allows for either integrated or isolated optimization. Both approaches are separately applied to a block model. The results demonstrate the model?s ability to produce optimal long-term sublevel stoping mine plans and the benefits of using an integrated approach. Keywords underground mine optimization, stope layouts, underground production scheduling, integer programming, mathematical programming application.

Oct 1, 2013

By P. Rice, A. Photolo, A. C. Barnard

Introduction -Sampling Tool Project (STP) -History -Results to date -Costs -Questions

Jan 1, 2005

Comminution is a vital part of minerals extraction, and therefore of the South African economy. The high cost and throughput-limiting nature of comminution forms a strong motivation for research directed at improving the efficiency of the process. Building on a ten year background of fundamental charge motion research, a new formal UCT flotation and communication group has been formed. The group is also moving strongly into the field of milling circuit modelling and simulation, based on close links formed with the Julius Kruttschnitt Mineral Research Centre (JKMRC) of Australia, and an international collaborative research programme.

Jan 1, 1998

By Ch. Schroeder, F. Collin, R. Charlier, Y. J. Cui

The paper proposes two numerical models ot the mechanical behaviour of chalk. First, an elasto-plastic constitutive law reproduces the different plastic mechanisms of the chalk and the influence of pore fluids by introducing the concept of suction. Secondly, a model able to reproduce time dependence behaviour. Eventually, the paper gives a simulation of an academic reservoir during depletion and waterflooding phase. Der Artikel stellt zwei numerische Modelle des mechanischen Verhaltens der Kreide vor. Das erste ist ein elasto-plastisches Modell, das verschiedene plastische Mechanismen der Kreide und den Einfluss von Porenflüssigkeit, unter dem Begriff der Suktion, reproduziert. Das zweite Modell berücksichtigt darüberhinaus das zeitabhängige Verhalten. Schliesslich zeigt die Veröffentlichung eine Simulation einer theoretischen Lagerstätte während der Entleerung und der Wasserinjektion. L'article propose deux modèles numériques du comportement mécanique de la craie. Le premier est une loi élasto-plastique qui reproduit les différents mécanismes plastiques de la craie et l'influence du fluide interstitiel par l'introduction de la notion de succion. Le second est un modèle prenant en compte les effets différés. Enfin, l'article présente une simulation d'un réservoir académique durant les phases de déplétion et d'injection d'eau.

Jan 1, 2003

By G. M. Wright

We are only as good as we are perceived to be by others and, whilst there is every opportunity to revise and polish our written works, there are no second chances with a spoken presentation. At every level, conferences and seminars have been metaphorical graveyards for many an academic reputation.

Jan 1, 1990

By M. Abdellatif

Keywords: Magnesium, pyrometallurgy, Mintek Extensive testwork on atmospheric thermal magnesium production has highlighted certain important fundamental and operational factors that have a major influence on magnesium extraction and its extraction rate, the condensation efficiency of magnesium, as well as on the quality of the condensed metal. The possible impact of these factors on the selection and preparation of raw materials, recipe choice, furnace electrical energy consumption, and on the refining requirements of the crude magnesium is discussed. Selected pilot plant operational and metallurgical data are also presented.

Jan 1, 2006

By S. K. Murphy, K. B. Le Bron, A. K. Ward, S. Hayes, T. Rangasamy

A process for evaluating different options for extraction of mining blocks is presented. The process is described and an example of the application of the process to a case study is presented. Un procédé pour évaluer différentes options pour l’extraction de blocs d’exploitation est présenté. Le procédé est décrit et un exemple de l’application du procédé à un cas particulier est présenté. Ein Prozeß für das Auswerten der unterschiedlichen Optionen für die Extraktion von Abbaublöcken wird dargestellt. Der Prozeß wird beschrieben und ein Beispiel der Anwendung des Prozesses zu einer Fallstudie wird dargestellt.

Jan 1, 2003

By R. Scott

This article describes and evaluates the establishment of Kuyasa Mining including the search for a suitable deposit, the ongoing lack of finance, and market constraints. Despite the dramatic initial growth and success of their Ikhwezi Colliery near Delmas, Mpumalanga, Kuyasa?s experiences offer some sobering arguments for significant changes to mineral rights ownership, the attitude of financial institutions and government policy if South Africa is to have a dynamic and successful junior and small-scale mining sector.

Jan 1, 1998

By M. F. Dlamini

The hydrodynamics of a hydrocyclone present a complex internal flow structure, the numerical simulation of which remains a non-trivial task. We report on three-dimensional water-only computational fluid dynamics (CFD) hydrocyclone flow field predictions and highlight some of the issues concerned with the development of a CFD model incorporating an air core. The potential for the application of CFD as a hydrocyclone design tool is also discussed. Physically realistic velocity profile predictions were obtained, which challenge the classical account of the hydrocyclone radial particle classification mechanism. A pressure field distribution consistent with literature reports was also predicted. Keywords: hydrocyclone, computational fluid dynamics (CFD),classification mechanism

Jan 1, 2005

The 108th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at The Country Club, Johannesburg, Napier Road, Auckland Park on Thursday, 11 August, 2005. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations, also to recipients of awards, senior members of industry, Honorary Life Fellows, past-presidents, our members and other guests, among them the following: Dr Con Fauconnier, President, Chamber of Mines of South Africa Prof. Jay Barton, President, The Geological Society of South Africa V. Townshend, President, Institute of Certificated Mechanical and Electric Engineering, South Africa M. Livingstone-Blevins, President, Institute of Certificated Mechanical and Electrical Engineers, South Africa Prof. B. Lacquet, President, South African Institute of Electrical Engineers Dr F. Malan, President, South African National Institute of Rock Engineering

Jan 1, 2005

By B. J. du Plessis

Automation of the conventional grinding circuits of Palabora Mining Company (PMC) required that adequate instrumentation and a control system had to be put in place, after which extensive testing had to be done to evaluate different grinding control strategies. The objective was either to optimize the particle size from the grinding circuit, or to increase milling circuit throughput while maintaining particle size at existing levels. Prior to automation of the process as described below the circuits were controlled manually. No on-line information on cyclone feed densities, cyclone feed flow or cyclone overflow particle size was available. This type of control relied heavily on interpretation of the process parameters by the operator and on his ability to make informed decisions on what the set points should be. An integral component of the automation process was the installation of a SCADA package (SysCad SDX) for implementing the on-line control strategy. A self-correcting model for prediction of cyclone particle size was developed and implemented on the SDX. The model is calibrated using values from the particle size analysers while they are operational. If the particle size analysers choke or fail for any reason, the model continues to provide a good estimate of the particle size. This technique ensures that a continuous particle size indication is available compared to the intermittent reading from the instrument. The continuous signal allows particle size to be used as a process variable for control purposes. A strategy was developed and implemented which allows for the production of a controlled grind size from the conventional milling circuit to the flotation circuit. The grinding control strategy allows for the control of particle size from the individual cyclone overflows. This strategy allows the operator of the process to increase or decrease production rate by specifying a coarser or finer grind size required for flotation.

Jan 1, 2001

By G. L. Smith

Central to the success of any mining company is the ability to manage capital investment effectively so as to ensure acceptable stakeholder returns within an overall strategic context. Critical to this process is the effective selection and implementation of a strategically aligned project portfolio that enables optimal resource exploitation while operating within mandated bounds and identified constraints. Consideration is given to the strategic long-term planning process, an investment prioritization methodology and specific tools and techniques based on the discounted cash flow philosophy.

Jan 1, 2007