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By M. Gershon

During the exploration phase of mine development, drilling location is in the hands of the geologist, and drilling is spread over the entire domain of the property or deposit boundary. During the mine planning and production phases, however, the mining engineer also needs to use the information obtained from the drilling program. Thus it is important that he/she have some input into the selection of the drillhole locations. Usually, when exploitation will center on one portion of the property for the immediate future, the mine engineer will want to have more of the drilling performed in this area. In the early stages, the purpose of the drilling was to make a decision concerning whether or not to develop a mine. Once the decision is made to proceed with this development, the mine engineer needs to know, with as much confidence as possible, the estimate of the ore grade at each location where mining will occur. This paper addresses the problem of drillhole location for the needs of the mining engineer. The goal is to compare a variety of approaches to drillhole location with a new approach developed by the author. This approach is based on the theory of geostatistics, with the estimation variance used as the quantitative measure of the confidence attained. The goal of the algorithm is to select those locations that minimize the estimation variance subject to constraints on the number of drillholes and the total cost of the drilling program. The kriging equations are used as another set of constraints. The resulting nonlinear optimization model is expressed in terms of binary (0 - 1) decision variables leading to a solution by the branch-and-bound procedure. The algorithm has been applied at a number of operating properties, and practical results and suggestions for implementation are provided.

Jan 1, 1987

By R. J. Mostert

The role of hardenability in the development of high-strength low-alloy (HSLA) steels is discussed. The applicability of the superhardenability treatment. a steel making technique for increased hardenability, to HSLA steels is indicated, and the literature on this treatment is reviewed. Several low-carbon superhardenability HSLA steels were designed by use of published superhardenability multiplying factors. It was found that the hardenability of these low-carbon steels can be increased to the same extent as that of medium-carbon steels. The mechanical properties as determined in normalized bars indicate that the superhardenability treatment can be used successfully in the production of low-carbon hot-rolled HSLA steels.

Jan 1, 1984

By P. E. Hand

SYNOPSIS This paper describes some of the markets for South African coal and their particular coal requirements. It describes how reserves are being used and suggests new strategies to make possible a synergistic ap¬proach that would benefit coal producers and end-users.

Jan 1, 1991

By P. R. Mothemela

The objective of the investigation is to optimize the truck and shovel operations for pre-stripping at New Vaal Colliery by introducing campaign mining. The aim of campaign mining is to improve the efficiency of the loading, hauling, dumping, and maintenance operations which are critical to the success of truck and shovel operations. The current loading (single-sided loading method), hauling, and dumping operations at New Vaal Colliery were found to be inefficient. Time studies were used as a major indicator to highlight the inefficiency of the truck and shovel operations, and it is recommended that an improved loading configuration, hauling, and dumping operations be implemented by using campaign mining. It is also recommended that a service truck be used to maintain the pre-stripping fleet in order to reduce travelling times to the main workshop. As expected, the improved operating conditions will lead to an increase in pre-stripping production.

Jan 1, 2013

By M. Bryson, V. Deeplaul

As a national facility, Mintek?s brief is to conduct high calibre research that allows the most effective utilization of South African resources. The research takes two different forms, with the efforts being directed at both high-risk endeavours that may lead to the development or adoption of new technologies or the reapplication of technologies to potential new operations. Starting in the 80s Mintek began developing a process to upgrade the UG2 ore and invested heavily in projects, equipment and people to service the industry. Some of the highlights of that work that has been conducted here include: ?Development of a milling and flotation process for UG2 ores ?Development of the ?Mintek Process? for maximizing PGM recovery for UG2 ores ?Conversion of the UG2 milling circuits to open circuit ?Development of a robust pilot plant facility for use in plant design studies ?Use of dense media as a waste rejection option ?Use of attritioners in flotation circuits. More recently, and with the future in mind, the following processes are being researched, some of which have already been commercially applied: ?Development of a flowsheet for Platreef ores ?Use of optical sorting technology for upgrading platinum ores ?Use of a mini-plant for reagent optimization studies. Each of the highlights listed above will be discussed in the paper.

Jan 1, 2004

By H. A. D. Kirsten

The skills differential between manpower supply and demand is due to deeply rooted socio- and politico-educational misconceptions that can be remedied only by a concerted cooperative effort on the part of the general public, the State, organized industry, organized engineering, and engineering education. This will require the general public to recognize that the reasons for the shortages in engineering manpower should be regarded as critical. Public perceptions of engineering, of the vocational and educational prospects in engineering, and of the skills required are poor. The spectrum of engineering vocations, the corresponding function profiles, the interaction between the vocations and the relative proportions of the vocations in the engineering team are in general not adequately appreciated. The recruitment and training of students and teaching staff, teaching facilities, educational curricula, practical training, qualifications, professional registration, and financing are aspects of engineering education that should be brought to the attention of all concerned. . In addition, the educational curricula for the various vocations need to be specified clearly and definitively if the overall mission of engineering education is to be properly appreciated. The uncertainties between university and technikon education and the pursuant vocations need to be resolved. This can be done only by defining the respective curricula in terms of the mental skills and scientific techniques required. The remedial actions with regard to the rationalization of engineering education comprise informing of the public; establishment of an active political lobby; revision of existing education policy; rationalization of existing educational infrastructure; promotion, development, and guidance of engineering student intake; financing of engineering education; accelerated creation of new employment opportunities; and monitoring of the supply and demand of high-level manpower. The parties required to nitiate these remedial actions are various State departments and corporations involved in engineering and industry, various departments of education, the Directorate of Technology of the Department of Trade and Industry, organized engineering education, organized engineering, organized industry, and the Human Sciences Research Council. Only if these interest groups actively initiate the various actions under the coordinated guidance of organized engineering wil the required results be achieved. The South African Engineering Association has proposed a comprehensive programme as strategy to solving the problem, and has obtained broad consensus from various State departments, organized engineering education and research, and the private sector. A joint venture between the Foundation for Research Development, the South African Engineering Association, and organized industry has been charged by the State President with the task of launching the programme.

Jan 1, 1991

By P. R. Jochens, D. D. Howat, C. W. Wolhuter

Prof D. D. Howat (Member): I am a man with a grievance this afternoon. The other authors of the paper entered into a conspiracy to ensure that I presented the paper, and finally even had the audacity to say that this was the least that could be expected from me as I had done so little of the other work. Looking at the distinguished audience here that includes some figures who have forgotten more about cement that some of us have ever learned, I realise how right the other authors were. I feel very much cast in the role of the fool who was pushed in where angels fear to tread. I hesitate to say, Sir, that I would not use the word angels in any definition of the authors of this paper. In presenting the paper, may I try to put forward a few simple points about cement that are probably as little known to the majority of the audience as they were to me-at least until very recently. Concrete, made by mixing Portland cement, sand, crushed rock and water is the most widely used constructional material in the world. Generally the production of actual Portland Cement is about two-thirds that of steel and by the time this is formed into concrete the total is about five times the world tonnage of steel produced. A very rough approximation suggests that world consumption of concrete is about one ton per person per annum. Apart from fresh water mankind consumes no other material in such quantities. What mankind originally required was a mortar to be used for joining blocks of stone or bricks. Such mortar was originally made from limestone burned in a kiln and then mixed with water. Production of mortar of this type began over 5,000 years ago. Some samples from pyramids in Egypt have shown this mortar to be in good condition although over 4,500 years old. The progress of technological development was very slow until 1824 when an English bricklayer, Joseph Aspidin, patented a new mortar material which he made by burning limestone and clay together in his kitchen stove. Aspdin called his product 'Portland Cement' because, in colour, it resembled a well-known building stone quarried in the Isle of Portland on the south coast of England. Aspid's same types of raw materials are used today in modern cement production and the product is still referred to as Portland cement. A lime-containing material such as chalk or shell and a clay-type material such as shale, slate or clay itself, are mixed in the required proportions, ground and fed to a kiln where the minimum burning temperature is about 1,500°C. The raw materials react to form hard chunks of a material known as 'clinker'. About 5 per cent of gypsum is added to the clinker and the mixture is then ground to a very fine powder, the function of the gypsum being to control the rate of setting of the concrete. The key oxides in cement production are lime, silica, alumina and iron oxide. The possible reactions occurring during and the products of the burning process are shown in Table I.

Jan 12, 1968

By J. Markgraaff

Because composites offer new solutions to materials problems, they are currently the focus of intense research and development worldwide. However, the natural tendency of users is to remain with tried materials in every situation of material selection. This approach ignores the tremendous advances that have been made in composite materials and their application. These advances enable engineers to tailor composites to suit specific applications such as the demanding needs of mining and industry in South Africa. However, the application of composites, where new and improved components and products are needed or are being developed is often hampered by the limited knowledge and experience of the engineers concerned. This paper presents some of the basic information needed for an appreciation of the terminology, definitions, and properties of various types of composites. It also reviews recent developments in manufacturing technology and product development that may find application in local industries and mining.

Jan 1, 1996

Minutes of the Annual General Meeting Held at Harmony Country Club on Wednesday, 2nd August, 1978, at 7.30 p.m. Mr A. N. Shand (Chairman of the O.F.S. and Klerksdorp Branch) was in the Chair. Also present were:.... Induction of Chairman Mr A. N. Shand introduced Mr H. M. W. Eschenburg by briefly outlining his past career and achievements, and, in calling upon him to take the Chair, wished him a very successful year of office..... Address by the President of the S.A.I.M.M. The Chairman introduced Mr Von Wielligh by outlining his career and achievements. After completing his education, he joined J.C.I. in 1936 as a sampler, and from that time served the company in many capacities, culminating with his appointment to the Board in 1974.....

Jan 1, 1979

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 O. A. W. Strydom, J. C. M. Wethmar, P. R. Jochens, D. D. Howat

Liquidus temperatures in the Cr-Fe-Si system in the composition range representative of ferrochromium-silicide produced in South Africa J. C. M. Wethmar, B.Se. (Eng.) Rand D. D. Howat,U B.Se. (Glas.), Ph.D.. F.I.M. P. R. Joehens, Pr.Eng., M.Sc. (Eng.) Rand, Ph.D., A.I.M. O. A. W. Strydom, M.Sc., Ph.D. Alloys in the composition range of chromium, 20 to 50 per cent, iron, 10 to 30 per cent, and silicon, 25 to 55 per cent, were subjected to both differential thermal analysis and the classical quench method so that the liquidus temperatures of ferrochromium-silicide alloys could be determined. The results are presented as liquidus curves on pseudo-binary sections at various ratios of chromium to iron and as liquidus isotherms in the ternary section.

By R. Ciccu

This paper examine the optimization of a beneficiation plant for recovering marketable barites from crude ores of different characteristics. The plant, part of a mining complex in Sardinia, consists of a jig section integrated with a flotation line. The problem has been studied using a suitable model of the process, based upon experimental and field data pertaining to both the characteristics of the feed material and the performance of machinery. Data have been automatically processed with the aid of a computer to find the optimum setting of each section, in order to maximize profit for each kind of ore separately fed to the plant. Moreover, the advantages of blending the various concentrates - not all of them individually marketable - are also demonstrated. The overall economic result can be improved provided suitable proportions of each kind of ore are fed to the plant. Such information is fundamental for the long-term planning of exploitation of available reserves, and provides guidelines for further prospecting. The paper illustrates the washability characteristics of the ore's and describes in detail the model adopted. The results of data processing are then presented in the form of computer graphs and discussed. Finally, conclusions are drawn regarding the advantages of resorting to Operations Research as an aid to management.

Jan 1, 1987

By J. D. Salter

Most diamonds are liberated from their ores by crushing. Diamond and other coarse grained mineral ores require carefully optimised crushing circuits. Recent advances in computer technology have made possible the on-line capture of crushing plant performance data and, hence, the accurate empirical modelling of the crushing process. Such models are used in simulation studies to determine the optimum operating conditions for a given plant. A system is described which allows operating data from mineral treatment processes to be logged. Up to 16 channels of data may be recorded simultaneously at sampling rates in the kiloHertz range per channel. A data storage and analysis procedure is described which allows the system to make full use of its sampling capabilities.

Jan 1, 1987

By M. Wu, X. Zhao

This paper presents an integrated pipeline transport system for thickened coal sludge, which combines pretreatment and pipeline transport with combustion techniques of thickened coal sludge. The pipeline can transport thickened coal sludge with a sufficiently high solids content (about72%?77%) and high apparent viscosity (about 1 000Pa?S?3,000 Pa?S) directly by pipeline having neither use for water nor an addition agent. The transport distance can be as high as 1 000 metres. In particular, the operating principles, key equipment and technical parameters of this integrated system are examined in this paper. The integrated system effectively causes no pollution to the environment because it is completely sealed, and conserves energy over traditional conveyer designs. Keywords: pipeline transport; integrated system; circulating fluidized bed boiler; thickened coal sludge; high solids content

Jan 1, 2007

By Y. Zhen, N. Topliffe, G. Shou

The typical service life for a long distance slurry pipeline is15 to 25 years. Determination of wear rate for a pipeline could have a high economic impact on the pipeline project. Wear is a combination of chemical corrosion and mechanical abrasion. The contribution of each factor has to be determined project by project. Normally, chemical corrosion dominates the pipe wear in fine slurry pipelines. These pipelines have been designed with a velocity between 1.5 m/s and 2.5 m/s. Solids are suspended with high homogeneity across the pipeline section. Bottom wear is not much greater than the top wear and not sensitive to velocity. The wear pattern in the pipeline transporting medium coarse solids, such as milled ore and tailings, is different. Wear concentrates on the bottom of pipeline and the outer bends, and is more sensitive to flow velocity. Wear distribution along the pipelines is similar.

Jan 1, 2007

By T. Vincent, J. Steele, C. Debrunner, M. Whitehorn

This paper presents current work on the development and use of stereovision for underground mining. Information on the calibration of the cameras and the feature-matching algorithm are presented. This system uses an intensity-based approach that evaluated correspondences along the epipolar line. Once features have been identified and their distance from the cameras computed, a three-dimensional map of the muck pile is developed. The approach used here uses a ray-tracing algorithm. This approach provides an uncertainty measure along with the elevation. A discussion of the use of this modelling information in the control of the LHD is included. Keywords: Robotics, automation, LHD, underground mining, vision sensing, task automation, tele-operation

Sep 1, 2001

ACCUMULATED FUNDS Balance at 30 June 1990 (Loss) income over expenditure for the year (63 154)

Jan 1, 1991

By W. J. Murray

Tests were conducted during the middle of this year to evaluate techniques and the equipment used in a novel continuous mining system for use in narrow reef tabular orebodies. Equipment was designed and supplied to test a mechanized drilling rig, a selection of rock breaking techniques and an integrated rock removal system, mounted on a self-advancing reciprocating flight conveyer. As the rock breaking techniques do not depend on the use of large quantities of conventional explosive the systems and equipment employed here have the potential to run continuously for 24hours per day. Whilst the tests carried out use simple prototype equipment employing established technologies, the long-term objective remains the use of sophisticated machinery capable of running continuously and un-manned, only interrupted by brief service intervals. Keywords: Hydro-fracturing, Rock breaking, Low energy, Propellant, Non-explosive, Safety, Continuous mining, Rocksplitter, Boulder buster, Ro-bust.

Sep 1, 2001

Balance Sheet at 30 June 1989 ACCUMULATED FUNDS Balance at 30 June 1988. Excess of income over expenditure for the year ended 30 June 1989

Jan 1, 1989

Balance Sheet at 30 June 1988 ACCUMULATED FUNDS Balance at 30 June 1987. Excess of income over expenditure for the year ended 30 June 1988

Jan 1, 1988