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By F. T. Cawood

The distinction between real estate ownership and that of interests in the property is fundamental to the appraisal of mineral properties. This distinction affects the nature and understanding of security of tenure and, consequently, the perception of what constitutes fair value. Legal matters are a particular concern because of their influence on security of tenure, ownership definition and use restrictions. The dynamics of the market and the complex interrelationships between the factors of production define value at a specific point in time for the bundle of rights, interests and assets that constitute a mineral property. Because each mineral property is unique, physically immobile and of a wasting nature, its usefulness to its owner and society must be optimized. The US Appraisal Institute (2001) classified the forces that affect land use as the cultural, political and economic attitudes of society. These forces culminate in laws that often dictate the purposes for doing appraisals. Once the legal definition of the asset is understood, valuers can decide on the valuation process that will support the final valuation approach.

Jan 1, 2004

By D. T. G. Emmett

[ ] South Africa, by a wide margin, is blessed with the largest known world reserves of platinum. The optimal use of these resources for the benefit of all South Africa?s peoples is a goal shared by industry, government and all South Africans. The challenge is to grow the industry in accordance with demand growth and thus to manage a long-term stable growth pattern for PGM usage world-wide. Amplats and the South African producers are well able to meet this challenge [ ] South Africa plays a critical role in the provision of Platinum Group Metals for world markets. In fact no other country has the productive capacity nor the geological reserves to supply the world?s platinum needs. The world required some 5 million ounces of Platinum in 1997 and South Africa supplied a full 74% thereof. The second major supplier, Russia provided a further 18% of world demand, primarily as a by-product of nickel production. Amplats satisfied about 37% of total world demand followed by Impala 20% and Lonhro at 12%.

Jan 1, 1998

By J. A. L. Napier

An analytical solution to the best choice of cutoff grade for a mine is deduced for an assumed model of selective mining. It is found that this choice is determined by the constancy of a special function, the Hamiltonian, over the life of the mine. It is suggested that the appropriate constant value for this function should be determined by the expected long-term average of the paylimit. In that case, the optimum profile can be calculated at each point in time according to the prevailing working cost and product price. In particular, a decision can be made between operation at the true paylimit or at the subsidized paylimit implied by either the lease and tax formulas or the assistance formula for gold mines. It is also shown how the basic formulation can be extended for 'use in the determination of the optimum joint paylimit for two products over the life of the mine.

Jan 1, 1983

By C. A. Ozturk

The compressive strength of rock (sc) has an important effect on design of structures in rock engineering. Compressive strength can be determined in the laboratory using the uniaxial compressive strength (UCS) test. Some other index tests, such as the point load test, are also used, particularly when suitable samples for UCS are not available. The quantification of rock texture has introduced a new method in rock engineering for estimating the mechanical and physical properties of rock materials from microscopic investigations. The aim of this study is to quantify rock texture to estimate rock strength from the texture coefficient (TC), which is determined from a statistical assessment of thin section images. Rock texture is quantified by twelve different images from a single thin section to increase the reliability of texture analysis. A data-set is prepared to investigate correlations between TC and sc. The statistical correlations are computed after classifying of the rock samples based on their lithology as well as grain features. Equations derived based on the results of this study are used to predict the approximate value of compressive strength from the texture coefficient. This method is particularly useful for preliminary studies in rock engineering projects prior to detailed site investigation.

Jan 1, 2014

By L. Rademan

The kinetic leaching behaviour of a low-grade surface gold ore and a high-grade reef ore were evaluated to determine the achievable gold recovery from these ores and particularly mixtures of these ores. The reef ore material has a head grade of 13.40 g/t with a relative standard deviation of 3%, and the unprocessed surface ore material a head grade of 0.43 g/t with a relative standard deviation of 15.6%. It is concluded that the kinetic leaching behaviour of these free milling gold ores during cyanidation, is not influenced by mixing of reef and surface ore material. No statistically significant relationship exists between the achievable recovery by direct cyanidation and the head grade of the material fed. No ideal ratio of surface ore to reef ore could be established. It is recommended that these materials should be processed simultaneously to minimize the costs, security risks, and losses incurred in transportation.

Jan 1, 2012

By H. Yilmaz

Tensile strength testing has been one of the most common physical property testing methods of thin spray-on liner (TSL) products worldwide. However, the variety of products tested has been insufficient for comparison purposes. Specimen preparation procedures and test parameters such as curing time and loading rate are not reported well. Comprehensive tensile strength testing on 20TSL products and one plain shotcrete brand was performed over 28days of curing period. Detailed information on the test procedures with particular attention on the important aspects during sample preparation and test execution are provided. As expected, the tensile strength increases with increasing curing period. The test results make the categorization and comparison of liner products possible.

Jan 1, 2010

By M. A. Hermanus

This paper examines the occupational health and safety performance (OHS) of the South African mining sector against the backdrop of changes in the composition of the sector, international trends in OHS performance, and the agreement on OHS milestones and targets by mining stakeholders at the Mine Health and Safety Summit of 2003. Although OHS performance has improved, progress is slow and there is need for significant rather than incremental change if the targets are to be realized. Since 2003, fatalities and injuries are 20?25% short of annual milestones and not all commodities show consistent improvement. Statistics on occupational health impacts are unavailable, but noise and respirable dust levels are known to be high in mines, with much work lying ahead to address exposures at source. Trends in regulating and addressing OHS hazards are discussed with reference to the notion of ?systems-thinking? and the targets. Efforts to improve OHS and to respond to changes in the sector are constrained by a lack of training and consistency in risk management, guidance for junior, small and artisanal miners, and holistic approaches to risk. For example, treating risk holistically would involve taking proper account of contractors and women in the workplace, and attending to human factors and ergonomics.

Jan 1, 2007

By A. M. Starfield

SYNOPSIS A description is given of a new computer programme that has been developed for the rapid computation of the changes in temperature and humidity of air passing through mine airways. The programme enables the ventilation engineer to calculate air temperature increases along airways with an ease that is comparable with that of looking up a set of graphs or tables in an engineering hand-book. The pertinent information for a particular airway can be fed to the computer either on a standard punched card, or by typing directly into the computer at a remote terminal teletype unit.

By C. Daly

The Faculty of Engineering at the University of New South Wales (UNSW) offers a core first-year engineering design and innovation course, ENGG1000, undertaken during the first and second semesters. This course is highly regarded in the sense that it provides an introduction to many concepts and activities that students will experience over the four-year minimum for which they are undergraduates at UNSW. Approximately 1400 students enrol in the semester 1 course across the Faculty, typically 80 of which undertake the Mining Engineering stream. Students in teams of between six and eight design and construct a physical model to represent an aspect of their chosen discipline. For example, in 2013 the mining engineers designed and built a model dragline. This paper concentrates a major aspect of the course ? the involvement of team members in group activities and the development of the associated skills of peer assessment and peer review as the course progresses over a period of 12 weeks. The term ?peer assessment? in this paper refers to the requirement for students to assess the design components of their peers. This course has a structured requirement in terms of how a successful design is a result of a sound design process rather than a ?try and see? approach. Each student must describe in detail the process they undertook to achieve their final design ? hence the approach is independent of the discipline and/or project selected. Peer review is a process whereby students review the contribution of their team members to the overall design. This activity encourages team involvement and interaction. The final assessment mark can be moderated by the outcome of this peer review, although it is run twice during the semester. The first ?run? is for feedback only during week six and hence no moderation is undertaken. It was found through consultation with students and from questionnaires that both processes are well accepted and highly regarded by students, as they give them a degree of ownership of the assessment process. In addition, the processes provide rapid and relevant feedback on the progress of individual students. Peer review and peer assessment are also considered to be very valuable tools for use in courses in succeeding years. For instance, many of the courses in mining engineering rely heavily on group assessment tasks.

Jan 1, 2014

By C. Daly

"The Faculty of Engineering at the University of New South Wales (UNSW) offers a core first-year engineering design and innovation course,ENGG1000, undertaken during the first and second semesters. This course is highly regarded in the sense that it provides an introduction to many concepts and activities that students will experience over the four-year minimum for which they are undergraduates at UNSW. Approximately 1400 students enrol in the semester 1 course across the Faculty, typically 80 of which undertake the Mining Engineering stream. Students in teams of between six and eight design and construct a physical model to represent an aspect of their chosen discipline. For example, in 2013 the mining engineers designed and built a model dragline. This paper concentrates a major aspect of the course - the involvement of team members in group activities and the development of the associated skills of peer assessment and peer review as the course progresses over a period of 12 weeks.The term ‘peer assessment’ in this paper refers to the requirement for students to assess the design components of their peers. This course has a structured requirement in terms of how a successful design is a result of a sound design process rather than a ‘try and see’ approach. Each student must describe in detail the process they undertook to achieve their final design - hence the approach is independent of the discipline and/or project selected.Peer review is a process whereby students review the contribution of their team members to the overall design. This activity encourages team involvement and interaction. The final assessment mark can be moderated by the outcome of this peer review, although it is run twice during the semester. The first ‘run’ is for feedback only during week six and hence no moderation is undertaken.It was found through consultation with students and from questionnaires that both processes are well accepted and highly regarded by students, as they give them a degree of ownership of the assessment process. In addition, the processes provide rapid and relevant feedback on the progress of individual students.Peer review and peer assessment are also considered to be very valuable tools for use in courses in succeeding years. For instance, many of the courses in mining engineering rely heavily on group assessment tasks."

Jan 1, 2014

By V. Tathavadkar

Worldwide TiO2is extracted from natural ilmenite, rutile, and anatase minerals via the sulphateand chloride processes. The sulphate process generates large volumes of less toxic wastes, whereas the chloride process, including the ilmenite-chloride process of DuPont, yields much lower volume of wastes, which are highly toxic and hazardous. The treatment and disposal of such hazardous chloride wastes is both expensive and difficult in terms of long-term monitoring. Besides the waste management and disposal, there is also a shortage of high-grade titanium dioxide minerals in nature, which consequently yields much larger tonnages of sulphate and chloride wastes. In the present investigation we report the results of an alternative titaniferous mineral beneficiation process based on soda ash roasting of minerals. Compared to the conventional processes for beneficiation of TiO2- ores, the alkali roasting of titaniferous offers several advantages including the zero process wastes. In the soda ash roasting process, the mineral is mixed with sodium carbonate and heated above 1023 K in air. The oxidative roasting of ores yields several complex alkali compounds, some of which produce a liquid mixture above 1123 K. In this paper, we have attempted to characterize the composition and physical chemistry of alkali-rich liquid phase. The phase equilibria in the Ti-(M:Fe)-Na-O system are evaluated and compared with the phases formed as a result of roasting reaction. The experimental results revealed that the composition of complex alkali liquid at the reaction interface plays an important role in determining the transport of O2-ions and decomposition of ilmenite. The roles of the crystal structure of mineral phases and their energetics are also emphasized in controlling their decomposition during alkali roasting. The presence of molten alkali in controlling the partitioning of water-soluble alkali salts and insoluble sodium titanate is also explained. Keywords: ilmenite, anatase, alkali roasting, phase equilibria.

Jan 1, 2004

By D. Ksinsik, R. Boisvert, D. Leblanc

Casting, cooling and crushing/sieving of ferroalloys has followed a well-established pattern in the whole ferroalloys industry for many years. Usually liquid metal or alloys are cast into flat open moulds of various shapes and forms, and after solidification the product is removed from such mould to further cool down to a temperature where subsequent handling steps are feasible. Common to all mechanical product fractioning is the generation of dust and fine size material with lower product value. For almost 10 years, Bécancour Silicon has investigated alternative roads to improve technology and/or reduce or solve problems related to those disadvantages. Since 1995 Bécancour Silicon operates a special silicon granulation plant targeted to product for the chemical treatment/conversion of silicon for silicones production. Prior to the development of the granulation process, various systems had been evaluated, among others the vibrating casting bed, now in operation elsewhere but judged inappropriate because of the tapping volumes to be handled at Bécancour Silicon and other disadvantages. After evaluation of all aspects of heat transfer, radiation, and conductivity in relation to transfer media and within the product, a novel system was designed and built.

Jan 1, 2004

By J. M. Garcia

This paper highlights several management practices from the oil and gas industry to support the proposition that financial performance in the finite, non-renewable resource business relates more to upstream rather than downstream activities. Based on the analysis of nine oil and gas companies, this study supports a previous study involving fourteen mining companies that showed reserves growth is one of the main levers of value creation in mining. Interestingly, this study also finds that the oil and gas industry has been historically more profitable than mining. The reason, it is argued, is that oil and gas companies count on management practices that focus primarily on the upstream segments of the business, compared to the traditional downstream focus of mining. This paper delves into these ideas to conclude that what mining may need to improve its competitive advantage is a new organizational framework. Another conclusion is that the upstream management focus is vital not only for strategy formulation in the resource business, but also for policy formulation in economies based on the export of finite, non-renewable resources.

Jan 1, 2011

The South African Institute for Mining and Metallurgy celebrated its 95th anniversary with a banquet at The Carlton on Friday, 2nd June, 1989. This event was attended by 600 people, including the Presidents of AS&TS, constituent societies, and other kindred bodies, together with members and their guests. The guest speaker was Mr Muray Hofmeyr, Chairman of the Johannesburg Consolidated Investment Company Limited, who gave an interesting and thought-provoking talk entitled 'Will we still be the best in the year 2001'

Jan 1, 1989

1. Book reviews Underwater tools, by Donald J. Hackman and Don W. Candy. Columbus (D.S.A.), Battelle Press, 1981. 152 pp. $32,95. Reviewer: B. Schmitz Uranium exploration case histories. Proceedings of Advisory Group Meeting Vienna, IAEA, 1981. Price: Austrian schillings 630. Reviewer: E. C. Kostlin Jet cutting technology, a review and bibliography, edited by Robin Brown. Published by BHRA Fluid Engineering, Cranfield, Bedford MK430AJ, England. Reviewer: D. O'Beirne 2. New Books Proceedings, Twelfth Congress of the Council of Mining and Metallurgical Institutions, by H. W. Glen (editor.) Johannesburg, The South African Institute of Mining and Metallurgy, 1982. 2 vols., 1060 pp. R78,85 (air-mail RI53,85). Amborite. Johannesburg, De Beers Industrial Diamond Division (P.O. Box 916), 1982. 6 pp. Free of charge. 3. New Journal BHRA Fluid Engineering has announced its new journal World Ports and Harbour Abstracts and the associated newsletter World Ports and Harbour News, which are issued from January 1983. The Abstracts is published bi-monthly and costs £60 in the V.K. and E.E.C., and £72 elsewhere. 4. Mintek reports Report 2134D On-line analysis, by X-ray diffraction, of fluorsparcontaining slurries. (First published 30th Sep., 1981.) Report 2135D A preliminary on-line analysis, by X-ray diffraction, of pyrite-containing slurries. (First published 30th Sep., 1981.) Report M28 The measurement of flow velocity distribution in fluids. Report M34 The determination, by atomic-absorption spectrophotometryusing electrothermal atomization, of platinum,palladium, rhodium, ruthenium, and iridium. Report M45 Two computer programmes for the calculation of massand heat balances in the production of high-carbon ferromanganese. Report M50 The development of an on-line gold analyser. Report M54 Major amounts of mercury in native gold from upper Witwatersrand sediments. Report M55 A new robust method for the treatment of analytical data. Report M57 The hydrometallurgical treatment of liquors generated by the leaching of a low-grade matte. Awards for inventions For inventing devices of exceptional value to the mining industry, two mining men were presented with awards in Johannesburg on 25th November, 1982, under the Chamber of Mines' Ideas and Suggestions Scheme. Mr W. W. Malan, President of the Chamber of Mines, made the presentations.

Jan 1, 1983

Dr T. F. Muller (Honorary President): "Mr President, gentlemen. May I congratulate the Institute on its 75th birthday, and your President on his comprehensive review of the Institute's 75 years. It is an interesting commentary on the affairs of the Institute that your President should refer to a speech made by a founder member 25 years ago on the occasion of your 50th Anniversary and then say there is no need to repeat what was given there, but that he would confine his remarks to bringing the Institute's history up to date. To me this suggests a remarkable continuity of thought and ideals-a welcome island of stability in an ever-changing world. One can somehow picture another future President, perhaps one of the younger and tougher members here today, doing the same thing in 25 years when you celebrate your centenary-and again someone doing the same in the year 2094 when your Institute is 200 years old! I hope they will recognise their debt to the early pioneers of the Institute gathered here today. In any event, this review of the fine achievements of the past 75 years is certain of an honoured place in the annals of the society. Here is a record of the onward march of technology in South Africa and a tribute to a long line of mining engineers, of chemists, metallurgists and geologists who made a greater contribution to the well-being and the prosperity of South Africans than South Africans generally are aware. Your Institute started off as a 'gold and cyanide club', peopled largely by chemists and metallurgists who made a signal contribution to the industry from the earliest times. Despite the addition to their ranks of ever-growing numbers of mining engineers, the metallurgist members have continued to make notable contributions. One recalls, for example, the manner in which they rose to the occasion to resolve the problems associated with the establishment of the uranium industry in this country. The creation of a major industry based on the existence of low grade uranium ores in the conglomerate reefs of our low grade goldfields is a classic example of the manner in which a new large industry can be rapidly created through the combined endeavours of all concerned. I noted with pleasure your remark, Mr President, that members of the Institute would like to keep up to date with recent progress in nuclear fuel matters and that members should be given the opportunity to study developments in their journal. I am sure that the National Institute of Metallurgy which conducts fuel research on behalf of the Atomic Energy Board and of the Uranium industry, and NUFCOR, which co-ordinates the uranium research programme, would be glad to co-operate if invited by the Institute to make periodical contributions to its journal. You have referred to the building up of our research organization and its dynamic approach to mining problems. I understand that the expenditure of the mineral industries on research exceeds one-third of the entire research expenditure of the private sector. South Africa is in the forefront of mining development and the focus of world attention is on the achievements of our scientists and mining engineers. We can look forward to continued advances in mining technology based on their vision and expertise. I share your disappointment, Mr President, that the Base Metals Division has ceased to exist; and that there is a resultant dearth of papers offered to the Institute on these important sections of mining and metallurgy. We are seeing some remarkable developments in the mining and beneficiation of base minerals, and it is in this area that I see the greatest potential for future expansion. If we can grasp the opportunities

By Nareetsile S., J. Kabwe

In the past few years Orapa and Letlhakane Mines have investigated various new technologies to enhance and improve production. The goal has been to improve productivity, reduce operating costs and make the mines more profitable The advent of Global Positioning Systems (GPS) in the early ’80s brought about the realization of this concept. Orapa and Letlhakane Mines started using GPS in 1999 and it is now used atLetlhakane mine for surveying, vehicle tracking and dispatching and for floor control system. Orapa Mine uses GPS in surveying, floor control and drill navigation. It will also be used for vehicle tracking and dispatching in mid-2001 following the installation of a fleet management and control system. The introduction of GPS at both Orapa and Letlhakane mines have improved productivity and reduced operating costs in the areas of drilling, topographic survey and floor control. In vehicle tracking and dispatching GPS has allowed for real-time information management for timeous decision-making which optimized fleet run time hours.

Sep 1, 2001

By T. Szendrei, S. Tose

The fracturing and movement of rock that occurs in the vicinity of a stemmed borehole charge in open pit mining operations are described by examining the effects of the emitted stress waves – shock and elastic – and the expansion of high-pressure detonation product gases. Three principal modes of momentum transfer to fractured rock are identified, all linked to gas expansion work. This work can be delivered radially (burden), axially (stemming), and in the collar zone (cratering). Flyrock is generated under unusual combinations of blast parameters and rock properties. Although infrequent and seldom predictable, the generation of flyrock can nonetheless be interpreted and modelled in terms of the principal mechanisms of rock projection described in this study. The physical processes underlying these principal mechanisms are identified and will permit the development of predictive models for flyrock velocities.

Dec 13, 2023

By O. F. Ochonogor

Laser metal deposition (LMD) is an additive manufacturing technique whereby a stream of metal powder is consolidated by a focused laser beam on the surface of a substrate or engineering component. The interaction zone between the laser beam and powder particles is scanned superficially, generating tracks of deposited material. The tracks are overlapped in a deposition strategy in accordance with slices of a CAD model. Successive layers of material are built up to fabricate a near net shape part. In this work, the technique is used to fabricate metal matrix composites (MMCs) by using an elementally blended feedstock combining metal and ceramic powders in the melt pool, which melt and solidify to create the required morphology. Ti6Al4V + TiC MMCs were produced with 10, 20, and 30 vol.% reinforcing ceramic, and Zr + TiC MMCs were fabricated with 10, 20, and 30 vol.% TiC. The deposited thin walls were analysed using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and indentation testing. In both systems, the analysis revealed the presence of partially melted TiC particles embedded in the metal matrix along with fine dendrites of re-solidified ceramic. The dendritic structures in the Ti-based composites were confirmed as TiC, whereas in the Zr-based composite the Zr metal reacts with theTiC to form ZrC, leaving Ti in solid solution. Both the MMCs show an increase in microhardness with increasing ceramic (carbide)content, reaching a peak HV0.1 value of 500 in the Zr- based MMC and HV0.1 of 550 in the Ti based MMC.

Jan 1, 2012

Models are used in engineering to reproduce reality as faithfully as possible so that the expected response of a system for given actions or inputs can be determined. In the field of rock engineering, both empirically based and numerical models are widely used to determine the likely response of the rock surrounding excavations. Many of the empirical models are developed from statistical analysis of case histories or from direct observation; however, empirical models are limited because they should be used only within the range of conditions of the observational database. Synergy exists between empirical and numerical models, because empirical models can be used to calibrate and validate numerical models. The empirical approach can benefit from the capability of numerical models to investigate specific mechanisms, which would not be possible using observations alone. Two cases are presented in which the synergy between empirical and numerical models is demonstrated. The first case examines the analysis of discontinuity effects on the strength of slender pillars in limestone mines, and the second case evaluates the effects of stress orientation on coal mine entry stability. It is concluded that numerical model calibration and verification comprises an important first stage in the successful application of models in rock engineering design. Application of numerical models allows mechanisms and interactions of various parameters to be analysed, greatly improving the understanding of the system. The improved understanding can be used to extend the application of empirical design methods, resulting in improved safety and efficiency of rock engineering designs.

Jan 1, 2014