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By W. A. Hodgson

"In order to be able to map the variation in the concentration of elements in soils, it is necessary to sample at intervals that will give adequate coverage of the area and will allow determination of the rate of fluctuation of concentration with distance in any environment. This rate of fluctuation with distance can be referred to as the continuity of concentration.The continuity of concentration in soils varies according to the chemical characteristics of the element being considered, the underlying rock type or orebody and in response to the dispersion processes that operated during soil formation. Within any environment there is a maximum distance between sampling points within which adjacent sample values are related. This distance, the critical sampling interval, can be determined by means of a correlograrm.Where the sampling grid has been chosen to provide an adequate coverage over unmineralized rock, adjacent samples being related, anomalies may be missed if the element continuity in the anomaly is less than in the background. Results show that a knowledge of the critical sampling interval of the environment being examined may used to select a more efficient sampling pattern for a geochemical survey."

Jan 1, 2014

By M. Kumral, S. Hmoud

Optimising the configuration of infill drill holes is an important step during mineral exploration campaigns. However, this optimisation process encompassing all possible drilling configurations within a mineral deposit is highly combinatorial and hard to solve in a reasonable time. This paper proposes using spatial clustering algorithms to divide the orebody into contiguous zones and target the best zones with infill drilling in order to reduce the size of this optimisation problem. Several clustering algorithms are assessed in a spatial context on hypothetical datasets. This evaluation shows that the hierarchical density-based spatial clustering application with noise (HDBSCAN) algorithm can be used in combination with the uniform manifold approximation and projection (UMAP) dimensionality reduction algorithm to identify contiguous zones in the orebody.

Sep 1, 2021

By Z. Botha

Sheryl Sandberg, the COO of Facebook, published a book titled 'Lean In', where she invites women to sit at the table. In summary, to 'sit at the table' entails not only embracing opportunity, but to actively seek out opportunities in leadership positions. Sandberg points out that, unfortunately, apart from institutional obstacles, a woman's own perceived limitations have a negative impact on her leadership ambitions. To create an environment where diversity will flourish, where everyone has a seat at the table and everyone has a voice, safety must be established first. To establish safety within a diverse team, there is power in relationships and connections. This study will first and foremost review theories in literature as to why diversity and inclusion are so important and the value that diversity brings to our industry. The study also recommends a few focus areas for improving diversity and inclusion in the industry.

Sep 1, 2022

1. New books Extractionmetallurgy'81. London, Institution of Mining and Metallurgy, 1981. 441 pp. $40. Structures and properties of engineering alloys, by W. F. Smith. London, McGraw-Hill, 1981. 512 pp. R89,65. Rock and mineral analysis, by W. M. Johnson and J. A. Maxwell (editors). 2nd ed. New York, Wiley, 1981. 424 pp. $40. Mining methods and equipment, by Mining Information Services. London, McGraw-Hill, 1981. 218 pp. International directory of acronyms in library, information and computer sciences, by P. M. Vaillancourt. New York, Bowker Publishing Co., 1980.516 pp. 2. New journals Trends in analytical chemistry (TRAC), Amsterdam, Elsevier, 12 issues per year. Subs. for Volume I (16 issues) D.H 95.50. Engineering management international, Amsterdam, Elsevier, 4 issues per year. V.S. $32.50, D.H. 70.00. 3. Mineral policy sector publications Mineral Bulletin MR 188. Vanadium: an imported mineral commodity. $3.60. Mineral Bulletin MR 190. Canadian mines: 1980 perspective. $3.00. Canadian mineral survey 1980, by the staff of Mineral Policy and Energy Sectors. $1.00. 4. NIM reports Report 2090 Observations made during the dig-out of a 48 MV A ferrochromium furnace. Report 2110 The investigation of a fracture on one side of a skip bridle in a mine shaft. Report 2111 Pilot-plant tests for the recovery of chromite and the noble metals from the UG-2 Reef at Maandagshoek. Report 2112 The behaviour of UG-2 chromite concentrates during smeUing. Report 2113 M uUivariable control of a milling circuit at East Driefontein Gold Mine. Report 2115 Estimation of material variation in powdered materials Report 2116 Optimum operation of a direct-reading spectrometer with excitation by a 5 kW inductively coupled plasma torch. Report 2121 Five robust indicators of central value. Report 2124 The direct determination, by differential pulse anodicstripping voUammetry at the thin mercury-film electrode,of cadmium, lead, and copper. Report 2127 The preparation of a reference material of South African zirconium concentrate from Richards Bay. Report 2128 The determination, by differential pulse anodic-stripping voltammetry at the thin mercury-film electrode, of cadmium and thallium in six NIMROC reference materials Report 2130 The organizing of conferences. Research grant The Board of Directors of International Precious Metals Institute in conjunction with Gemini Industries, Inc., a California-based refiner of precious metals, recently announced a Gemini Research Grant of $3000 will be awarded annually to a graduate student who is pursuing studies in metallurgy, chemical processes as it pertains to precious metals, or materials sciences, and who is performing or planning research studies in the precious metals. Accidents and diseases The Third International Colloquium for the Prevention of Occupational Accidents and Diseases in the Iron and Metal Industry is to be held on 15th and 16th June, 1982, in Palma de Mallorca, Spain.

Jan 1, 1981

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 O. K. H. Sheff

An editorial in the April 1990 edition of Mining Magazine is worth a wider audience in South Africa, particularly as the SAIMM enters its own centenary decade and the process of change in the minerals industry world-wide makes increasing demands on the professionalism of its leaders. The editorial considers the changing status of engineers, who up to the 1880s had been held in high regard by society. Alumina and bauxite Economists forecast a slower economic growth rate in 1990, but expect continued increase in demand for aluminum at a 3 per cent annual rate during the decade. Structural and numerical analysis Struceng & Femcad (structural analysis and finiteelement method) is a conference and exhibition that is to be held in Grenoble (France) on 17th and 18th October, 1990. It is sponsored by the Institute for Industrial Technology Transfer (ITT-International).

Jan 1, 1990

"I have been involved in the refractory industry for many years and at some time or another I have designed materials, tested materials, manufactured materials, installed materials, in fact I have done everything except actually chemically analyzed a refractory material.So I would not even begin to tell you how to analyse a refractory material. I'm sure everyone here knows more about chemical analysis than I do.However you could regard me as a customer with and perhaps the insights I have developed may help in putting the role of chemical analysis in the Refractories into perspective.For a start, let's take a step back and ask why we test refractories. The refractories handbook of the American Foundry Association gives four reasons:1. To determine appropriate specification.2. For quality control, to ensure conformance to specifications.3. To provide special property information not available elsewhere.4. For postmortem analysis to determine property changes in service and provideinformation that can point the way to better service.I want to discuss these points with regard to the role of chemical analysis and in particular the abuse of in house chemical analysis facilities. Let me talk first about detelmining appropriate specifications. Most refractory products are made from alumino-silicate raw materials.The phase diagram for alumino and silica is as follows:"

Jan 1, 2014

By A. W. S. Schumann

A. W. S. Schumann The first reason for todays success lies in the very high standard which was set by our speakers today and I think that we owe a very special vote of thanks to Messrs P. M. C. Wilson, A. A. Oakes, M. J. Deats, A. C. Coetzee, R. E. Burnton and J. G. Ferguson. This, however, cannot account for the fact that there was a tremendous response even before anyone knew who was going to speak or what they were going to speak about. I suggest that the response was enthusiastic because people expected a more informal gathering with a greater opportunity for feedback, for an exchange of views and for questions and answers. The very popularity of the idea has defeated its own ends to some extent. This gathering is too big and many people must have been left with questions unanswered. Possibly one should arrange for a number of meeting places-there are many in the Chamber and the surrounding mining houses-and then have separate meetings in the morning with joint reporting session in the afternoon. Alternatively, we could have a symposium after the colloquium, using Webster's definition of a symposium as as 'a drinking party of merry fellows'. We all know that it is easy to discuss mining into the small hours. Obviously one cannot summarise todays papers and discussions, but I would like to make a few comments on technical matters and after that I would like to speak for a moment about what I see as major trends or tendencies which arise from discussions of this nature. Regarding the question of placing a village on a mine or away from a mine, I would mention that there is quite a body of literature on the adverse sociological effects on the development of children in any community in which the great majority of parents share the same occupation. It is something to be avoided if possible. We discussed the concept of the moving stockpile. If this is proved to be successful, it could save a considerable amount of money for Escom who could then avoid the construction of very large and costly staithes which are now regarded as parts of power stations. One does not see why both a moving stockpile and a staith should be necessary. By the way, speaking of Escom, I see that Mr Bob Scott is here; he has stopped pulling my leg by saying that we sell stone to Escom; perhaps someone has told him that if this is true, it must be the cheapest stone you can buy in this country. My next point relates to the use of epidiascope. It struck me again that this instrument which provides a visual image to accompany your message, can be very effective if it is properly used. These papers speak of a great deal of hard work which went into their preparation, and one really feels that the authors should have taken a few minutes more to prepare their drawings specifically for the epidiascope. There should be nothing on the drawing which is not necessary to illustrate a particular point and there should be nothing on the drawing which is not visible from the back of the hall. In particular, if one cannot read the figures along the sides, then one

The February General Meeting of the Institute was held in Kelvin House, Johannesburg, on 19th February, 1969 at 4.30 p.m. Mr R. C. J. Goode (President) was in the Chair. There were also present forty-six Members, including Messrs H. E. Cross, A. R. C. Fowler, P. Lambooy, D. G. Maxwell, Dr J. T. McIntyre, Messrs J. A. Nixon, V. C. Robinson and P. W. J. van Rensburg (Council Members), Messrs G. Abdinor, H. F. Allan, R. E. Barnes, M. M. Bayley, J. K. Boyd, R. R. M. Cousens, R. E. F. Cowley, D. Savile Davis, H. J. Davisson, C. T. Fenton, J. Fergusson, J. Fritz, M. L. Fitzgerald, J. M. Gosnell, J. C. Hall, S. A. Hancox, D. M. Jamieson, Dr D. G. Krige, Messrs J. E. V. Leeuwen, A. Louw, C. F. Louw, B. H. L. Leach, R. B. MacGillivray, C. S. McPhail, E. Margo, G. G. Nicolson, E. Pavitt, M. P. Pearse, F. O. Read, Dr M. D. G. Salamon, Dr H. S. Sichel, Messrs D. Storrar, S. G. Taussig, A. H. Taute, E. B. Viljoen and P. A. von Wielligh. Sixteen Associate Members, including Messrs S. T. Baron, W. M. Fitzpatrick, M. R. Fuller-Good, P. R. Garcia, H. G. Gericke, P. D. Hatfield, R. Hemp, G. S. Lee, Miss V. E. Marting, Messrs A. H. Munro, R. C. Power, O. F. Rheeder, G. C. Thompson and N. Zolezzi. Two Graduates, Messrs D. Bosley and J. C. Sutherland. Three Affiliates, Messrs R. K. Briggs, A. B. Cook and G. M. Thain. One Student, Mr P. W. Henrard. Twenty-three Visitors, including Messrs N. J. W. Bell, R. G. Bushell, A. Bryan, J. F. Cillie, C. M. de Beer, Dr F. H. Deist, Messrs D. S. Drake, P. G. du Plessis, R. W. Hodgson, D. M. Hawkins, S. C. H. Kearns, M. D. Labuschagne, L. Munro,R. Murchison and L. Robinson. Secretary, Mr D. C. Visser. Total present: Ninety-two. OBITUARIES The President: "It is my sad duty to announce the death of the following members of the Institute. Edward Frank Jud Bulman, Life Member, who joined the Institute in 1931 and passed away on 7th November, 1968. Elmar Fenton Chapin, Member, who joined the Institute in 1941 and passed away on 17th November, 1968. Solly Rabinowitz Rabson, Member, who joined the Institute in 1944 and passed away on 13th February, 1969. Mr. Rabson was the holder of two certificates of merit for papers presented to the Institute.

By D White, L. Lorenzen

Sampling and metallurgical testwork during various phases of engineering studies is of paramount importance for a robust processing plant design. When developing a process flowsheet, risks in achieving desirable financial outcomes are minimised by ensuring that appropriate sampling and adequate metallurgical testwork support the engineering and cost estimation at each phase of project development. The quality and type of samples used for metallurgical testwork are just as important as the metallurgical testwork itself. The key characteristic required of any sample is that it represents some defined portion of a mineral deposit. Representivity should consider the spatial orientation, lithology, alteration, degree of oxidation, mineralogy, and competency of the ore such as hardness and abrasiveness. Statistically representative sampling procedures and an appropriate metallurgical testwork program should be designed to bring metallurgical understanding up to feasibility study standard and to give a basis for process plant design. The authors have observed that the quality of sampling and quantity of metallurgical testwork carried out during the various phases of engineering studies are often insufficient to truly support a robust plant design. Some designs are based on benchmarks of apparently similar ore bodies or rely on buoyant metal prices supporting cash flows until rectifications can be implemented. The paper will discuss important aspects of sampling and testwork required for engineering studies in designing process plants. Keywords: Sampling, metallurgical testwork, studies, design

Jan 1, 2020

By A. Mainza, I. Govender, Elbasher M. E. Ahmed

A mechanistic description of axial segregation in rotating drum flows remains an open question. Consequently, optimal mixing of grinding balls and rocks for efficient breakage, maximum production of fines, and slurry transport is seldom achieved. Experimental and numerical studies of granular mixtures in rotating drums identify alternating axial bands that eventually coarsen in the long-term limit. Most models of axial segregation are limited to binary mixtures and cannot always predict the logarithmic coarsening effects observed experimentally. A key missing factor is a robust description of the axial free surface profile that is valid across a wide range of flow regimes. We present a practical model of the axial free surface profile by linking it to readily-derived geometric features of the cross-sectional S-shaped free surface profile. A parametric study shows good agreement with experimental measurements reported in the literature and heuristically valid trends.

May 1, 2021

Primary roof support represents the first line of defence against rockrelated falls of ground in underground mines, and improper utilization or misunderstanding of the applicability and behaviour of primary support can be costly from a safety standpoint. This is a major concern for underground mines, as roof support is the single most costly expense from a mining operational perspective. This is further backed by the evidence that, in the USA, hundreds of injuries and fatalities still occur each year because of rib, roof, and massive roof falls. Additionally, the fully-grouted passive rebar, fully-grouted tension rebar, and resin-assisted mechanical anchor bolts, which constitute a large portion (89%) of the 68 million bolts installed each year in underground mines in the USA can vary in cost quite dramatically. To mitigate this concern a study was conducted in 2010 by the National Institute of Occupational Safety and Health, in conjunction with Southern Illinois University of Carbondale, to assess the performance of primary roofbolts in underground coal mines for improved safety and cost. This was accomplished using underground roofbolt monitoring solutions, field data, and numerical modelling to better understand the quasi-static behaviour of underground coal mine roofs and the response behaviour of the bolts. In particular, over 170 instrumented extensometers, closure meters, shear meters, fully-grouted passive rebar, fully-grouted tension rebar, and resin-assisted mechanical roofbolts were installed at three coal mines across the USA. Of these three mines, two used the room and pillar extraction method and the other used the longwall extraction method. There was no evidence to indicate a difference in performance of the active primary roofbolts compared with the passive primary roofbolts. Additionally, in the initial loading phase, the active bolts showed no difference in loading, indicating that tension bleed-off is of more of a concern than originally thought. Lastly, for the initial computer modelling studies, challenges still remain in obtaining a good match to the in situ bolt measurements and replicating the discontinuous roof rock and in situ bolt behaviour over time.

Jan 1, 2014

By C. A. Green, M. A. T. Cocquerel, R. T. Gates

"Engineering studies by Selection Trust, Limited, initially in connection with the development of a copper and nickel deposit for Bamangwato Concessions, Limited, and subsequently for several other clients, have required a large number of metallurgical design calculations. The flash smelting process, developed by Outokumpu Oy in Finland, has been selected as the most suitable method for these projects and the computer programs described in this paper have been developed to facilitate the computation.The data required by the programs arc the chemical and mineralogical analyses of the concentrate, gangue and flux materials and the specification of possible fuels. The required grade of furnace matte is set as the main design parameter and the programs calculate detailed heat and material balances for the smelting process."

Jan 1, 2014

By R. Mumbi, M. Peart, E. Arinaitwe, B. Mbao, J. Zulu

Since 1925, xanthates have been widely used in sulfide flotation due to their low cost, ease of manufacture, and ability to float most value species. However, the industry's increasing need for safer and more selective alternatives, driven by low head grades, poor-quality, difficult-to-process ore with complex mineralogy, and stricter environmental regulations, has led to the development of Solvay's AERO® XR series of collectors. These custom-formulated products are based on greener chemistries and offer metallurgical benefits that are similar to or better than those of xanthates, without the safety concerns. Developed through Solvay's Flotation Matrix (FM) 100 approach, the XR series collectors are suitable for a wide range of applications, including the processing of Cu, Zn, and Cu-Ni, as well as the flotation of precious metals. This paper will highlight the differences between xanthates and XR series collectors, and present case studies of their successful commercial application at various global operations.

Jan 1, 2023

By Y. Ren, B. Yang

The magnetic field characteristics due to electromagnetic stirring in the secondary cooling zone of an extra-thick slab during continuous casting are numerically determined using Maxwell's equations, with particular emphasis on the distribution of magnetic induction intensity and electromagnetic force, as well as the influence of process parameters on the magnetic field. The orientation of the electromagnetic force is the same when the electromagnetic stirrers at the 30° and 60° posistions of the arc-shaped slab are powered in the same direction; otherwise, the orientation is opposite. The magnetic induction at the centre of the section of the stirrer's central axis at the 30° positio, as well as the current, frequency, and fitting formulae, are as follows: B = {0.075I.(1/A)-0.3} mT and B = {-1.75f.(1/Hz)+22} mT. The electromagnetic force and current fitting formula at the central point of the B-B section is F = {0.03168I2.(1/A2)-03.762I.(1/A)+326.7} N/m3, and the fitting formula of electromagnetic force and frequency at the centre point is divided into two segments. The first takes the form of a parabola: = {-21((f-4.3).(1/Hz)2)+970} N/m3, and the second segment is negative linear: F = {-1.65f.(1/Hz)+51.5} N/m3.

Apr 16, 2024

The nature of metallurgical engineering?applying and optimising chemical and physical processing of ores into useful materials?is reviewed. Important trends that shape the context in which metallurgical engineers practise are identified ? increased global production of primary metals, declining prices, environmental constraints, and increased property requirements of materials. A successful department of metallurgical engineering is one which employs a team of academic leaders to develop graduate engineers who are productive across the full range of metallurgical processing. Keywords: metallurgical engineering, primary metals, commodity prices, processing

Jan 1, 2003

By I. Serepa, N. C. Steenkamp

Investigations were conducted to determine the condition and stability of the existing decline at amine in the Kalahari Manganese Field, Northern Cape Province, South Africa. During the inspection of the decline, voids were identified behind the concrete lining on the hangingwall and sidewalls over a total linear distance of 230 m. The voids did not provide confinement and, as a result, self-mining was occurring behind the lining. Water was flowing into the decline, over a total linear distance of 100 m, at areas where the decline intersected incompetent rock units, causing softening of the concrete lining and deterioration of the surrounding rock mass. Further damage to the concrete lining was caused by expansion and contraction of the wet red clay unit. Remedial work comprised void filling and water sealing to prevent further deterioration of the decline and ensure that it remained operable for the remainder of the life of mine. Void filling was accomplished by drilling rows of holes along the decline to access the voids and filling the voids with foam. This was followed by the sealing with polymer fluids. Telescopic pipes were also installed to allow water to drain off. A visual inspection was conducted and check-holes were drilled to assess the quality of the remedial work. The void filling material had penetrated cracks in the concrete lining, and areas where voids were intersected by check-holes were re-filled. Additional holes were drilled to re-seal areas that were still wet. The remedial work was completed successfully, as all voids were filled and stability achieved without compromising the concrete lining. The ingress of groundwater was also reduced to some residual dampness.

Mar 2, 2022

By R. Weber

Methane explosions in underground coal mines are a major concern across the mining industry. After the Pike River disaster, Arnot Coal became even more aware of the explosion risk. To determine whether Arnot has adequate precautions against a methane explosion, such as the one that led to the Pike River disaster, a literature survey covering the causes of the incident and what preventative measures should have been in place was conducted. Many different methane explosion prevention methods were evaluated, as well as codes of practice. Based on the findings, Arnot?s measures to prevent conditions favourable for a methane explosion were evaluated.

Jan 1, 2014

By D. N. Esfahani, K. Khazen, M. Mohammadi

Electrowinning is one of the nickel recovery processes from solutions obtained from the leaching of nickel sources. Every year significant amounts of nickel products are used in various industrial processes and daily life, such as catalysts or batteries, which are a valuable source of nickel for recovery. Nickel purity is also very important in the electrowinning process, because the amount of impurities in nickel such as sulphur, if greater than 100 ppm, make it unsuitable for use in catalysts and plating. Because sulfur is intrinsic to the sulphate electrowinning system, we needed to investigate parameters that can affect the quality and purity of nickel. In this regard, experiments were performed in static and circulating electrowinning processes. A monitoring and circulation system was designed and built to measure voltage, current and temperature as well as to circulate the solution in the system at a specified rate. It was then observed that nickel ion concentration, pH, using the circulation system and additives, were factors affecting the purity and quality of nickel, and in the best case the amount of sulphur in nickel was below 100 ppm. Keywords: Nickel, electrowinning, sulphur impurity

Jan 1, 2020

By A. Brodt, I. Mezhibovsky

The traditional vertical transportation systems deliver both gangue and useful mineral. The extraction of the desired minerals requires the construction of mineral processing and waste management plants, driving production costs, and often creating a negative environmental impact. The proposed technology is an integration of mineral processing within the transportation system. The mined rock is crushed and then loaded into a vertical lifting system filled with heavy media, with an intermediate density between the mineral and the waste rock. Driven by gravity separation, the desired mineral floats to the earth's surface, while the waste sinks. Delivered minerals and sunk waste is extracted from the heavy media and is then regenerated to a dry state. The useful mineral should be suitable for further use, and the waste used for backfilling. Remained residues of the heavy media may be recycled and reused in the vertical transportation system. Trials of the proposed process in a pilot format have confirmed economic and environmental advantages over traditional methods of transportation and mineral processing technologies. Keywords: Gravitational processes of mineral processing, separation in heavy media, vertical transportation to earth's surface by floating up

Jan 1, 2020