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FEBRUARY GENERAL MEETING The January General Meeting of the Institute was held in Kelvin House, Johannesburg on 21st January, 1970, at 4.30 p.m. Mr V. C. Robinson (Vice-President) was in the Chair. There were also present eighteen Members, Messrs M. Barcza, A. R. C. Fowler, R. C. J. Goode, Prof J. de V. Lambrechts, Messrs T. C. A. Meyer, J. A. Nixon, V. C. Robinson and P. W. J. van Rensburg (Council Members), C. A. Border, D. F. H. Grave, S. D. Hill, A. F. Lee, W. L. le Roux, C. S. Macphail, D. L Starkey, S. G. Taussig, W. T. L Wayman and Dr A. Whillier. Three Associate Members, Dr M. I. Brittan, Messrs R. Hemp and M. J. Martinson. One Student, Mr R. P. W. Henrard. Two Visitors, Dr N. G. W. Cook and Mr J. B. Smith. Secretary, Mr D. C. Visser. Total present: Twenty-six. 1. OBITUARY The Vice-President: "It is my sad duty to announce the death of the following members of the Institute: Reginald Gordon McConnell, Member, who joined the Institute on 24th April, 1946 and passed away on 26th September, 1969. James Henry Moore, Member, who joined the Institute on 28th February, 1951 and passed away on 2nd January, 1970. As a mark of respect to the memory of the deceased and in sympathy with the bereaved I would ask those present to stand and observe a few moments silence." 2. MINUTES The Vice-President: "May we confirm the Minutes of the General Meetings held on 15th October and 19th November, 1969, as published in the December, 1969 issue of the Journal?" 3. MEMBERSHIP The Vice-President: "I have pleasure in announcing that the names of the under-mentioned candidates, having been published in accordance with By-Law 5.2.2, Council has elected them to membership of the Institute in the following grades: Member: Woodford Anson Gilbert. Associate Members: Michael John Harvey Tonking, Schalk Willem Vorster, Edward Alfred Cole, Johannes Godlieb Bosch. Graduate: Leonard Raymond Kilpatrick. Affiliates: Clive Frere Knight Pouiton, David Philip Ayliff, Kenneth Gillings, Edward Gilbert East. Students: Stirling Graham Low, Petrus Stephanus van der Merwe, Louis Johannes Fourie, Clive Maxwell Winterstein. MEMBERS TRANSFERRED TO A HIGHER GRADE From Associate Member to Member: Albert Arthur Hazell, Neville Martin Hayne. "I welcome the newly elected members to the Institute and congratulate the members who had been transferred to a higher grade. 4. GENERAL BUSINESS The Vice-President: "I wish to announce that except for the student prizes awarded at the November meeting, Council has decided to make no awards for 1969. Are there any further matters to raise under the heading of General? If not, we will proceed to the next item on the agenda which is the presentation of tonight's paper. 5. PAPER FOR PRESENTATION The Vice-President: "Professor Starfield may I call on you to deliver the paper entitled "A rapid method of calculating temperature increases along mine airways". After the presentation of the paper, the Vice-President said: The Vice-President: "Thank you very much, Professor Starfield. Gentlemen, I think that many of you here, who have to do with the design of mines in an age where costs and difficulties generally, are increasing at a rate which we find almost impossible to keep up with, I would agree with you that we are fortunate to have a band of people like Professor Starfield, and others who are dedicated to producing the tools, and methods which we need to sort out these problems. I am sure that you would agree with me, that the old rule-of-thumb methods are finished forever, that we can never go back to the methods which served us in the past, when we were close to the surface and had not met the conditions which we are meeting now, and which we are going to meet in an increasing degree in the future. It is to people like Professor Starfield, with these clear, completely logically described new methods, that we look for the solution of our problems in the future. I think the whole problem of layout of any mine, is one where you can reliably prognosticate what you are likely to find in a variety of circumstances to meet the wide range of things which must happen when you consider the costs in these modern operations. Thank you very much, Professor Starfield, for coming and giving us this paper. Thank you for making plain to me how these mathematical models of yours are used. I am sure that what you have said will be a very valuable addition to the archives of this Institution. Thank you very much, indeed, and Gentlemen, will you please show your appreciation in the normal way." (Applause). Professor J. de V. Lambrechts, Mr R. Hemp and Dr A. Whillier then contributed to the discussion. (These contributions will appear in a later issue of the Journal.) PAPERS OPEN FOR DISCUSSION The Vice-President: "Listed on the agenda are papers open for discussion. I would suggest that anyone wishing to contribute to these papers submit their contributions to the Secretary in writing." CONCLUSION The Vice-President: "I wish to thank members and visitors for their attendance, and now declare the meeting closed." The meeting closed at 5.30 p.m

By F. T. Cawood, T. Chikande, H. R. Phillips

Underground mines require electricity to operate both the main surface fans and auxiliary systems, with primary ventilation systems typically accounting for approximately 40–60% of the mine’s overall electricity consumption. The primary reason for this considerable expense is that most underground ventilation systems are designed for peak demand, regardless of the actual demand, which is commonly dictated by diesel equipment usage in trackless mining operations. Most platinum mines on the Great Dyke in Zimbabwe tend to operate their ventilation systems at this peak level, despite the mine’s air quantity being well in excess of the ‘true’ ventilation needs. This is due to a lack of appropriate ventilation controls. The authors designed and installed a ventilation-on-demand system at one of the bord and pillar platinum mines to minimize the use of redundant air in underground operations. Fourth industrial revolution techniques were applied to the environmental monitoring and tracking systems thereby optimizing air quantity demands. The mine managed to reduce its annual power consumption by 23% through the implementation of manual control and time-of-day scheduling levels of the ventilationon- demand concept. There was also a 6% productivity improvement, mainly attributable to an increased face time as a result of the significant reduction in the re-entry period following a blast. This paper introduces a novel concept of ventilation optimization through digital transformation targeting mainly room and pillar platinum mines. A system was designed, installed, and commissioned, though there is currently an ongoing optimization process to harness the full benefits such as productivity enhancement, reduced power costs, and improved worker health.

Dec 13, 2022

Papers of Interest The following papers may be of interest to members. APCOM The Thirteenth International Symposium on the Application of Operation Research and Computer Techniques for Decision Making in the Mineral Industries will be held at the Technical University CIausthaI, Federal Republic of Germany, from 6th to 11th October, 1975.

Jan 1, 1975

By P. Stefanek, N. Duda, B. Jachni, P. Stefaniak, B. Bursa

The Zelazny Most Tailings Storage Facility (TSF) is the largest reservoir of post–flotation tailings in Europe. The total amount of tailings from the mines in Lubin, Rudna, and Polkowice are stored each year at the disposal facility, which reaches approximately 30 million tons. It is crucial to accurately monitor and maintain such a huge storage facility, for the safety and economics of the entire region. In general, the monitoring network installed at the Zelazny Most TSF includes four groups of components: (a) geotechnical network (VW pore pressure transducers and inclinometers), (b) hydrological network (open piezometers, water level gauges, drainage discharge measurements, (c) geodetic survey network (e.g. surface and in-depth benchmarks, laser measurements, GPS measurements within GEOMOS network and (d) seismic network (e.g. accelerometer stations, cone penetration tests.) Apart from the above, chemical water analyses, tests of soil samples, monitoring of spigotting processes, and monitoring of relief wells’ discharge are also conducted. In total, approximately 2900 monitoring instruments are installed within the area of the Zelazny Most TSF. Such large amounts of data from the various information sources makes manual data analysis by the engineers almost impossible. In this paper we discuss a machine learning driven approach to improve the quality of the monitoring and maintenance of such facilities. We focus on the seismic cone penetration test (SCPT) data analysis. First, we carefully describe the collected data, its quality and availability. Then we discuss possible events that can occur in the TSF that need to be predicted using SCPT. Based on the information obtained in these two steps, the applicability of several machine learning methods is estimated. Some of them are then tested on available historical data. The algorithms described in this article will be further developed in the IlluMINEation project (H2020).

Sep 1, 2021

By C. Musingwini, A. S. Nhleko, M. J. Mahase

"In an environment like the mining industry, which is characterized by different stakeholders with multiple objectives, multi-criteria decision analysis (MCDA) is a useful approach for optimal decision-making. The application of MCDA techniques in the mining industry has predominantly been in mine planning and related problems, although no comprehensive survey has previously been undertaken to establish the application trends. A survey of the use of MCDA techniques was therefore conducted using case studies from the literature. It was noted that often two or more methods are applied to the same problem in order to increase confidence in the solution derived. As the number of criteria and alternatives increases, some methods become inefficient. A combination of the analytic hierarchy process (AHP) method with other MCDA techniques was the most frequently used approach, indicating the efficiency of the AHP method, especially when evaluating problems with more criteria and fewer alternatives. A combination of fuzzy theory with AHP or other methods incorporates uncertainty. The findings from the survey will benefit users applying MCDA techniques to solve mine planning and related problems.IntroductionA country’s natural resources serve the needs of different groups of people within the country. These different groups are collectively known as stakeholders (Herath and Prato, 2006). Stakeholders have different needs, preferences, and expectations, which describe and define the criteria to be considered in decision-making. The options available as solutions describe the alternatives in decisionmaking theory. The criteria and alternatives have to be evaluated simultaneously when making decisions, and this is when multicriteria decision analysis (MCDA) techniques become invaluable (Herath and Prato, 2006) because the human mind is considered to be limited when solving complex and intangible problems with several criteria and alternatives (Saaty, 2007). MCDA techniques belong to a broad group of techniques called multi-criteria decision-making (MCDM) techniques. The other group of techniques within MCDM comprises the multi-objective decision-making (MODM) techniques. MODM techniques are generally used to solve problems with an infinite number of alternatives, while MCDA techniques are generally used to solve problems with a finite number of alternatives (Musingwini, 2010)."

Jan 1, 2016

By G. Asbjörnsson, E. Hulthén, P. Papadopoulou, C. M. Evertsson

Crushing plant managers need to assess, manage, and communicate the environmental impact induced by their crushing plant operations as a step towards the sustainable development of the company. However, performing reliable environmental impact calculations of crushing plants can be challenging when the availability of operational and emission data is low, and when the company’s environmental expertise is not adapted and connected to plant operations (or does not currently exist). To address these challenges, this paper proposes a practical approach where the lifecycle assessment methodology (LCA) is combined with process simulations in a web-based tool. To describe what functionality such a tool should have to be incorporated into a company’s workflow, the system that surrounds a crushing plant is analysed. Further, a case study with a three-stage crushing plant is introduced to showcase how the simulated power draw results produced with the beta version of the tool can be compared to measured sensor data from the crushing plant for one operational day. The results indicate that the simulation tool can provide an adequate estimation of the specific energy for the different material fractions and give an overview of the environmental impact of the process caused by electricity and explosives consumption. Plant managers and operators can use this tool to calculate the environmental impacts of their plant and simulate how different operational strategies influence them. Keywords: LCA, environmental impact, coarse comminution, crushing plant

Jan 1, 2020

By W. W. de Graaf, M. J. Ntsekhe

Klipspruit Colliery is experiencing coal losses, which leads to a negative impact on coal production and subsequently loss in revenue. This study aimed to identify the possible causes of coal losses in the No. 4 upper and lower seams. The objectives were to identify potential sources of coal losses through a literature survey, to identify areas where the coal losses occurred, to determine factors affecting coal losses, and to identify the most cost-effective methods to reduce coal losses. Highwall losses, top-of-coal losses, and coal edge losses were identified as the major areas of coal loss at Klipspruit. These losses were mostly attributed to the drilling and blasting practises of the pre-split, interburden waste, and the coal seams. Recommendations include re-visiting the current pre-split design and the tolerances adopted for the interburden and coal seam drilling and blasting design. It is furthermore recommended that Klipspruit implement a continuous improvement plan for the drilling and blasting and refresher training for the blasting crew and operators.

Jun 10, 2024

The Technical Programme Committee-Metals Technology of The South African Institute of Mining and Metallurgy, in association with its Vaal Triangle Branch, held a one-day colloquium on 18th April, 1989, the theme being 'Ferous Pyrometalurgy: A Challenge for South Africa'. The venue was the Auditorium 100 at the campus of the Vaal Triangle Technikon in Vanderbijlpark. Project and contract management A Project and Contract Management Conference is to be held on 19th and 20th September, 1989, at the C SIR, Pretoria. Powder metallurgy The PM 90 exhibition is to be held in Wembley, London, from 2nd to 6th July, 1990. The wide range of powders, processing machinery, and powder-metallurgy components at the exhibition will reflect the growth in this highly specialist industry. Castings and forgings Exhibition organizers, FMJ International Publications Ltd, are set to build upon the success of Castings & Forgings '88, which was held as a joint event with Pat- Cast '88. Castings & Forgings '89-with Pat-Cast '89- has already generated a high level of interest, which has been reflected in the demand for stands. Furnaces FURNACES '90, the eighth in this series of exhibitions for the thermal-processing industry, will be held in Solihul, West Midlands, England, on 6th and 7th March, 1990.

Jan 1, 1989

By T. Wajima

Recovery of precious metals from hydrochloric solution using sulfur-impregnated carbonaceous adsorbent was examined. Sulfur-impregnated adsorbent with adsorption abilities of precious metals can be prepared from activated carbon using pyrolysis at 600 oC under 10 % H2S gas flow, and the adsorbed Au and Pd were precipitated as metal phase on the surface of the adsorbent. The adsorbents after precious metals adsorption were burned at 700 oC to obtain the residue mainly containing precious metals. The adsorbent was found to be highly efficient and selective for the uptake of precious metals, especially Au, in the presence of excess base metal ions from simulated spent automotive catalyst eluted solution using a column pack test. Keywords: Gold, platinum, palladium, reduction precipitation

Jan 1, 2020

By M. Getz, G. Asbjörnsson, M. Evertsson, E. Clausen

The mining and minerals processing industry is gradually being digitalised to improve efficiency and reduce waste. One aspect of this transition is to ensure that relevant process-data in sufficient quality and quantity is given to the operator in the right format and at the right time to improve decision-making. Augmented reality (AR) can serve as a potential ICT-based support tool for human operators to achieve this goal. With AR, virtual information is combined with the real world in real-time. Therefore, AR technology has the potential to fulfil the need for improved data visualisation in Industry 4.0. This article is the result of a collaborative effort of Chalmers University of Technology and RWTH Aachen University to identify selected state-of-the-art applications of AR that are currently being applied in the mining and minerals industry or selected related industries. This paper aims to show opportunities for the application of AR in the mining and mineral processing industry with selected conceptual applications. This paper concludes with several requirements identified as necessary to implement the conceptual applications of AR in the mining and minerals industry. Keywords: Augmented reality, mining, mineral processing

Jan 1, 2020

By F. L. D. Cloete

he above article by E. Barnea, which appeared in the January 1978 issue of the Journal (vol. 78, no. 6, pp. 143-145), calls for comment in view of the author's claims for the novelty of his proof. He states in his article that its main purpose is to give a mathematically acceptable proof by induction of the 'recently proposed' equation

Jan 1, 1978

By M. J. Nicol

On page 51, the equation numbered.... On page 52, the equation numbered .... On page 53, the arrangement of the equation.... Canadian reports Asbestos by G.O. Vagt.l0 pp. Chromium by D. G. Law-West. 6 pp. Iron and Steel by T. R. Mclnnis. 15 pp. Titanium and Titanium Dioxide by M. A. Boucher. 7 pp. Vanadium by D. Shaw. 7 pp.

Jan 1, 1984

By A. F. van der Merwe, R-D. Taylor, M. Jacobs, F. H. Conradie

Total bound moisture (TBM) is a typical quality indicator of industrial-grade gypsum. This gypsum is comprised of three distinct phases, namely anhydrite, dihydrate, and hemihydrate, of which only the latter is of much industrial use. TBM analysis is a lengthy laboratory procedure, and an artificial neural network (ANN) TBM inference measurement is proposed as a fast and online alternative. An ANN inference model for gypsum TBM based on plant data was developed. The inputs to the network were primarily focused on the plant's calciner, and different network topologies, data divisions, and transfer functions were investigated. Furthermore, the applicability of the TBM value as a quality indicator was investigated based on a gypsum phase analysis. A strong correlation between TBM and the gypsum hemihydrate and anhydrite content was found, validating the plant target TBM of 5.8% as a quality indicator. A network topology consisting of one hidden layer with logarithmic-sigmoid (logsig) and pure linear (purelin) transfer functions showed the best performance (R > 90%).

Oct 3, 2023

By E. M. W. Skinner

Various models of near-surface kimberlite pipe emplacement have been proposed over the years. These include a top-down, phreatomagmatic model, a bottom-up, embryonic pipe model and three top-down explosive dyke models. AU of these models consider kimberlites as essentially the same rock type. However, different kimberlites have different pipe shapes and contain different rock types with very specific mineral assemblages and textures and therefore are likely to have been emplaced by different processes. Some authors have considered local geological differences as the principal reason for the contrasting geology but others argue that, while geological differences might contribute locally the petrographic peculiarities of particular kimberlites may be due mainly to inherent compositional differences specifically in the ratios of juvenile CO2 and H2O.

Jan 1, 2010

By P. Kohler, T. D. Sampson, T. H. Tunley

The Metsep Process for the separation and recovery of zinc, iron, and hydrochloric acid from spent pickle liquors by T. H. TUNLEY, B.Sc. (Ch em. Eng.) (Visitor), P. KOHLER (Visitor), and T. D. SAMPSON, Pr. Eng., B.Sc. (Chem. Eng.), B.Econ. (Visitor) A spray roaster has been installed in the Johannesburg area for the treatment of spent liquors from a variety of small pickling operations. A new process was developed for the processing of the liquor that is contaminated with zinc chloride, and a commercial plant was built incorporating this process. An ionexchange plant separates the zinc from the iron chloride, and a liquid-liquid-extraction plant converts the zinc chloride to zinc sulphate and recovers the hydrochloric acid.

Jan 5, 1976

By M. J. Nicol

An electrochemical investigation of the dissolution of copper, nickel, and copper-nickel alloys in ammonium carbonate solutions by M. J. NICOL, Ph.D., B.Sc. (Hons.) (Wits.) (Visitor) The dissolution of copper and nickel in ammonium carbonate solution was studied by techniques involving electrohemical anodic dissolution and ring-disc electrodes. The rate of oxidation of both copper and nickel by copper (11) was shown to be controlled mainly by diffusion to the surface. Variations in rate with changes in copper (11) concentration, agitation, pH, ammonia concentration, temperature, and copper (I) concentration were investigated and rationalized in terms of their effects on the electrochemical half-reactions involved. Evidence was found for the passivation of nickel and nickel-copper alloys of more than 50 per cent nickel.

Jan 6, 1975

By M. U. Ozbay, D. R. Lougher

An in-situ experimental programme was carried out to improve the understanding of the rockmass and pillar behaviour in moderately deep hard-rock mines. The experiments were carried out at Impala Platinum mines and consisted of precise levelling measurements in the footwall of the reef, stress measurements in pillars, convergence measurements in the stope, and petroscope observations in pillars. The results were analyzed using a computer program in an attempt to quantify the characteristic behaviour of the rockmass as well as the pillars. The measured off-reef displacement data were found to co11fonn to the trends obtained from elastic modelling and the correlation could be improved by modelling the small pillars with reduced modulus to simulate yielding' of the pillars. The stress strain curve obtained from analyzing the in situ results, showed that a 6x 3 xl m pillar yields without significant load shedding at peak stress levels of approximately 208 MPa. The closure measurements confirmed that the mechanism of yielding is mainly that of pillars punching into the foundations. Slight to moderate sidewall fracturing and slabbing might be contributing to yielding, but to a much lesser degree than the former mechanism, as the petroscope observation revealed the existence of an intact region beyond 0,6m from the pillar sides.

Jan 1, 1995

The 96th Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room of the Transvaal Automobile Club in Johannesburg on Wednesday, 11th August, 1993. OBITUARIES The President announced the deaths of the following members of the Institute during the past year. Life Fellow E.F. Laschinger. Other Members R.K. Boright, J.S. Jacobi, R.D. Power, J.H. Cannon, C.J. du Plooy, L.B. Mcrae, C.P. Rossouw, A.L. Sillars, A.W. Heugh, R.K. Briggs, P.J. Stark, and C.S. Stott. As a mark of respect to the memory of the deceased and in sympathy with the bereaved, all rose and observed a moment of silence.

Jan 1, 1993

By H. J. E. Hamel

Some aspects of the deformation behaviour and temperature rise during instantaneous compression loading of high purity aluminium By H. J. E. HAMEL The influence of deformation speed on the deformation behaviour of high purity aluminium was investigated. By varying the initial height-to-diameter ratio a considerable influence on the deformation behaviour could be noticed. Lubrication of the specimen end faces was found to have an influence on the flow behaviour and on the roughness of the specimen interface at pressing platens. The results of temperature measurements during deformation agree with work-hardening behaviour of the specimens. Flow curves calculated with the measured temperature rises do not agree with results obtained at lower strains by other workers. The possible reasons are discussed.

By J. S. Preston

The properties of some recently developed solvent-extraction reagents for the separation of cobalt and nickel sulphate solutions are reported. New commercial extractants based on alkyl phosphonic and alkyl phosphinic acids are described. These reagents show much improved selectivity for cobalt compared with established extractants. Some novel extractants developed at Mintek for the selective recovery of nickel in the presence of cobalt are also described. These reagents, which are based on mixtures of carboxylic acids and non-chelating oximes, are of interest in that no commercial nickel-selective reagents are currently available. Graphs showing metal loading and stripping, and pH-functionality, are presented. together with details of the metal separations achieved in batch countercurrent- extraction experiments with the various reagents.

Jan 1, 1983