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By D. Hanekom

Over the past couple of years, Anglo Platinum has made extensive use of technology within the core disciplines (geology, evaluation, survey, and planning) that collectively form part of mineral resource management (MRM). While these technologies were primarily developed to enable geology, evaluation, survey, and planning to carry out their daily tasks, with the main objective of supporting the mine?s production effort, they have also enhanced the disciplines? ability to produce the required outputs within the annual business planning cycle. Anglo Platinum has developed a very comprehensive business planning process, and these technologies play a vital role in enabling both the quality and quantity of inputs into the process, and also the value-add of the final product. This prompted a question regarding the practical application of the CADSMine software. If we changed our thinking in how we applied the software, would it be possible to further improve on the time taken to deliver a business plan? In changing the current planning approach, would we be able to further simplify the process? Is there a way to reduce the data generated in order to enhance the time taken to do reporting, as the CADSMine software is totally network dependent? Less data should equal faster reporting. This paper focuses on the practical application of the CADSMine software, and demonstrates the value-add to the business planning process that can be gained if the mine design methodology is changed from individual panels to bigger blocks representing a raise line.

Jan 1, 2012

By A. Santana, J. Jankolovits, G. S. Reyes

The flotation of sulfide ores that contain carbonaceous gangue requires significant operational and chemical intervention to achieve suitable metallurgical outcomes. Carbonaceous gangue dilutes concentrate grades, alters the froth behaviour, reduces operational stability, adsorbs reagents, and reduces value recovery. Carbon management processing strategies like preflotation and depression are often presented as point solutions. Moreover, oversimplified mechanisms of carbon depressants belie their complex and nuanced impact on flotation behaviour. Optimising the flotation of carbonaceous sulfide ores requires a holistic consideration of interactions between the carbon management reagents and the processing strategy, ore mineralogy, flotation behaviour, flowsheet, and all other aspects of the flotation system. Examples are shown where conventional, simplistic mechanisms of carbon depressants fail to explain the observed flotation behaviour. The multifaceted impacts of carbon depressants on froth behaviour, collector performance, and value recovery highlight the need for a holistic approach to carbon management. Keywords: Carbon management, carbonaceous ores, sulfide flotation, carbon depressant

Jan 1, 2020

By M. Smit, N. C. J. Dempers, S. Lunkov, C. Saguru, J. Nel

A common method for the recovery of copper is by heap leaching, solvent extraction, and electrowinning. During solvent extraction, the solution is continuously recycled, and it is necessary to remove impurities that build up in the raffinate. For the process investigated in this study, the main impurities include Fe, Co, As, and Zn. Recovery of these impurities can provide economic benefits while adhering to legal and environmental constraints. Such impurities are often removed by precipitation utilizing a neutralizing agent, such as limestone or lime, but it is also possible to remove the impurities by sulfide precipitation. Sodium hydrosulfide (NaHS) is used to selectively precipitate copper, arsenic, and zinc from a solvent-extraction raffinate stream. The resulting sulfide precipitate is bagged and sent to a roaster for further treatment. The design of the sulfide precipitation was investigated to optimize the processing conditions (including temperature, pressure, and residence time), the materials of construction, and the toxicity and explosive nature of the hydrogen sulfide gas produced

Jan 1, 2023

By R. Weideman, K. du Preez

Biological sulfate reduction has become a successful treatment alternative for acid mine drainage and Mintek is developing biological processes for treatment of highsulfate mine waters. Treatment of these high-sulfate waters is achieved by sulfatereducing bacteria that reduce sulfate to produce sulfide as a product, in the form of H2S and HS− at neutral pH. This introduces the opportunity to apply treated effluents from biological treatment processes for the recovery of metals, such as copper, from metallurgical waste streams. This study models the kinetics of copper sulfide precipitation from a complex bioleach liquor. The results indicated a rapid rate of reaction and the formation of covellite, suggesting the potential to use biogenic sulfide to recover copper as a metal sulfide product.

Jan 1, 2023

By M. R. MacIver, M. Pawlik, H. Alizadeh

Treatment of tailings is an integral component of mineral processing. Tailings with a high clay content are a challenge for the mineral processing industry; e.g. the clay slimes produced from production of phosphate in the mid-western United States and the fine tailings produced from oil sands production in western Canada. Dispersants are a commonly used process aid, but their impact on the structure and settling properties of high clay content tailings is not well understood. The paper describes the changes in composition and bitumen release that occur when mature fine tailings (MFT) are treated with a polymeric dispersant (lignosulfonate.) Synchrotron-source computed tomography (CT) was used to obtain high-resolution 3D images of samples prepared at varying dosages of dispersant. The CT method permits a powerful visualisation of the internal structure and composition of the samples. These insights will enhance our understanding of the structural characteristics of mineral tailings relevant to solid-liquid separation by flocculation and thickening. Keywords: Dewatering, dispersion, dispersants, chemical treatment, computed tomography

Jan 1, 2020

By B. Besa, S. Nalukui

Globally, the demand for mineral products is ever increasing. Extraction of these mineral resources results in the continuous production of a huge volume of waste material, including tailing dumps. The mass of tailings usually exceeds the actual resource and often contains hazardous contaminants. This study investigated the effects of tailings disposal on soil, water, and air quality in the Nampundwe area. Water, soil, and dust samples were collected from different locations in the surrounding communities. The constituents analysed in the samples included copper, cobalt, iron, sulfate, and silica. According to the results obtained, some seepages occurred from the tailings impoundment to the shallow aquifer in the area. However, the general water quality meets the Zambia Environmental Management Agency (ZEMA) statutory limits. Recorded concentrations of sulfate (1500 mg/l), copper (1.5 mg/l), cobalt (1.0 mg/l), iron (2.0 mg/l), and silica were between 0.003 mg/l and 705 mg/l, which is far below ZEMA’s statutory limit. Silica concentration was also evident in the air. The highest concentration recorded was 260 ppcc (particle per cubic centimeter) recorded in July 2019 from the northern direction of the tailings dam. The concentration was below the statutory limit of 350 ppcc. The topsoil from the northern part of the tailings recorded a silica dust concentration of 39.9 ppcc. Iron was evident in the underground soil with a concentration of 8.01 ppcc, cobalt 0.005 ppcc, copper 0.051 ppcc, while sulfate was recorded as 0.41 ppcc.

Oct 9, 2024

I appreciate the honour that has been bestowed upon me by my election as President of this Institute. We are starting what I believe will be a challenging year. The first challenge facing the Institute is financial. From the accounts for you will note that the Institute operated at a loss for the first time since 1987. average membership subscription was increased by only 10 per cent, reflecting desire to keep costs down in the minerals industry. The Institute will therefore to rely on other income to meet its budget requirements and break even financially. source of these funds will be the activities of the Technical Programme Committees. disciplines-Mining, Extraction Metallurgy, and Metals Technology are planning programmes for the coming year. I urge al members to increase their support of colloquia schools. Increased membership would also bring in more funds. Please, therefore, encourage colleagues who are not yet members of the Institute to join it.

Jan 1, 1991

By C. Montoya

This paper shows, through a case study, the impact of multivariate grade modelling upon mine design and mine planning. A deposit explored by drill holes is considered, in which the grades of five elements (copper, silver, molybdenum, arsenic, and antimony) are of interest. Forty alternative models of the deposit are constructed by fitting the joint correlation structure of the grade variables and using conditional cosimulation. In addition, a reference model, obtained by averaging the alternative models, is also considered. The study shows that the resulting mine design (final pit characteristics and production schedules) is sensitive to the grade model under consideration, and that the design based on the reference model may not be optimal when compared to the alternative models based on cosimulation. However, when assuming a given long-term plan and extraction sequence, the grades and net present value (NPV) calculated on the reference model are unbiased with respect to those calculated on the alternative models with the same extraction sequence. The latter allow assessing the possible dispersion of the actual grades and NPV around their expected values, and are useful for the planner in order to determine the probability of meeting given production targets and of exceeding or falling short of given threshold grades. Additionally, unlike cosimulation, the separate simulation of each grade variable leads to unrealistic resource models and to biased results in mine design and mine planning. This approach should therefore be avoided, unless the grade variables are spatially uncorrelated.

Jan 1, 2012

By S. Stuurman

Inorganic acids such as sulphuric acid have found use together with certain reducing agents in leaching of copper-cobalt oxide ores. These reagents are not ideal due to the adverse effect the inorganic acids generally have on the environment and the high costs of the reducing agents. In this study a copper-cobalt oxide ore from the Central African Copperbelt was leached in two different environments; sulphuric acid in conjunction with hydrogen peroxide as a reducing agent and tartaric acid. The effects of acid concentration, reducing agent concentration, and temperature were independently determined for both leaching environments. The sulphuric acid concentration was varied between 0.4 M and 1.2 M and the concentration of hydrogen peroxide between 4.0 M and 6.5 M, while the tartaric acid concentration was varied between 0.15 M and 0.35 M. The temperature was varied between 20°C and 50°C. The results showed that the extraction of both copper and cobalt increased with sulphuric acid concentration, reaching a peak at approximately 0.8 M and then decreasing at higher acid concentrations. A similar increase and decrease in metal extraction was observed when the reducing agent was increased. In leaching with tartaric acid, the extraction of cobalt was much higher than that of copper, although extraction of both metals increased with acid concentration. Additions of small amounts of hydrogen peroxide were found to increase cobalt extraction in tartaric acid but had a minimal effect on copper. An increase in the solution temperature had a significant effect in the organic acid environment, with the effect on cobalt extraction being much more pronounced than on copper.

Jan 1, 2014

By S. Soren, K. Deo Mehta, G. Jha

The paper aims to find a sustainable sintering process through cleaner means, in order to achieve the desired outputs with zero environmental impact. At present, sintering has no control over its environmental impacts. These impacts occur when fossil fuels such as coal and coke are used in metallurgical sintering. These fossil fuels are undoubtedly effective in their assigned reducing task, but simultaneously emit about 220 kg of GHGs (greenhouse gases) per tonne of sinter produced. The current attempt has focused on reducing these emission levels by switching from coke to a renewable fuel source such as biomass. Biomass is a cleaner fuel source with a significantly lower emission footprint compared to coke. In the experimental campaign, sawdust and wood-charcoal were used in substitution for coke. Experiments were designed in a progressing substitution to obtain the maximum substitution ability without compromising the sinter properties. Sawdust as raw biomass source optimally substituted 10% of coke. The substitution levels were remarkably higher (30%) for wood charcoal due to its low moisture and high calorific values. A fuel blend with 30% biomass and remaining coke succeeded in producing a sinter with acceptable quality indices. Sinters prepared with or without biomass contribution shared an identical phase transformation and microstructures. In order to to maintain consistency in the process, every effort was made to maintain all operational and process parameters identically, except for the fuelling framework. Keywords: Sintering, sustainable, biomass, GHGs, fuel substitution

Jan 1, 2020

By J. W. D. Groenewald, L. Auret, B. S. Lindner, E. C. Nienaber

Mineral processing plants have complicated control strategies, with different control layers, multiple interacting loops, and feedforward disturbance rejection. The complicated control strategies mean that oscillations can arise and propagate to multiple loops and degrade the control performance. Oscillation detection techniques, such as the spectral envelope method, can be applied to detect oscillations within an observation window. However, the start- and end-points of the oscillations within the observation window cannot be identified with current oscillation detection techniques. The start- and end-points would be useful to label the oscillatory intervals, and then to use these labels to identify process conditions associated with the oscillation. In this paper, a pattern recognition technique, Density-Based Spatial Clustering of Applications with Noise (DBSCAN), was used to label oscillation intervals. An oscillation diagnosis workflow combining spectral envelope and DBSCAN was demonstrated on an industrial case study of oscillations in a flotation circuit concentrate sump. The workflow successfully detected the oscillation, labelled the oscillatory intervals, and enabled accurate root cause analysis. The impact of time series features, namely the signal power ratio () and the oscillation frequency, on the performance and optimal parameter selection of DBSCAN was also investigated. Low oscillation frequencies and low s negatively affected the performance of DBSCAN. Additionally, the results indicated that higher oscillation frequency was related to higher optimal values for the lag parameter. Keywords: Oscillation diagnosis, process monitoring, data mining, clustering, flotation control

Jan 1, 2020

By D. P. Roberts

This investigation aimed to simulate the experiments performed by Nic Gay (Gay, N.C.1976. Fracture growth around openings in large blocks of rock subjected to uniaxial and biaxial compression. International journal of Rock Mechanics and Minining Sciences and Geomechical Abstracts, vol. 13. pp. 231-243) on fracture growth around openings in blocks of rock subjected to uniaxial and biaxial compression, using the Elfen discrete element code. The results of the physical experiments indicated a number of trends that were successfully replicated in the numerical simulations, including crushing ahead of the face, the formation of a sub-vertical tensile fracture at centre-span, the formation of groups of fractures originating from the crushed face zone, the formation of large corner-to-corner fractures which precede sample failure, and linking of slot corner and sample corner fractures leading to sample failure. In addition, other features were apparent that were not reported by Gay. It is believed that these took the form of conjugate shear fractures (as reported by Gay in a previous paper) and other features that may have been altered or inhibited by the presence of pre-existing structure in the physical samples. It was found that the samples, though nominally made up of the same rock type, must have had significantly differing properties. The presence of pre-existing structures may have contributed to this discrepancy. Strain measurements from the physical experiments were reasonably well matched, except where the gauge lay directly in the path of advancing fractures.

Jan 1, 2012

By F. S. A. de Frey, F. C. Kruger

Personnel management has undergone a remarkable change over the course of the past ten years. Personnel departments have played an increasingly important role, which today requires highly trained people and cannot be adequately served by the lesser qualified officials of yesteryear. Changes in the mining industry that stem from the demand for skilled labour to keep pace with technological developments and the mechanization of mines today demand that emphasis should be placed on the maximum utilization of manpower. Maximum utilization of manpower calls for more scientific and effective methods of recruiting, selecting, training, and placing workers so as to offer them the best opportunities for development and promotion, which naturally ensure a minimum labour turnover and eliminate labour unrest. This can be achieved only if well-qualified and properly trained personnel administrators are prepared to accept the challenge and apply themselves purposefully by assisting line mangement with the attainment of the company's corporate objectives.

Jan 1, 1982

By E. Lwamba

The aim of this study was to examine the effect of grain size distribution control of the raw material mixture on the permeability of the green sinter bed and the properties of the produced sinter. This was achieved by evaluating the granulation characteristics of the sinter mixture (moisture content, granulation time and mean granule diameter) in terms of its green bed permeability, and evaluating the productivity of the sinter bed, the coke rate, tumble index (TI), abrasion index (AI), reduction disintegration index(RDI) and reducibility (RI) of the produced sinter. The raw sinter mixtures contained combinations of Thabazimbi iron ore, Sishen iron ore, coke, lime and return fines. The grain size distributions were controlled by removing the ?0.5 mm size fractions of the return fines and coke, and the ?1 mm size fraction of lime. Of the examined mixtures, a mixture of 20 mass% Thabazimbi iron ore, 80 mass% Sishen iron ore and fluxes where the coke, lime and return fines were all sized had the highest granulation effectiveness and permeability. The sintering properties of the mixtures in which the grain size distributions were controlled, were very similar for all the mixtures, but superior to the base case mixture in which the grain size distribution was not controlled. Keywords: Thabazimbi iron ore; Sishen iron ore; granulation, permeability, grain size distribution; sinter.

Jan 1, 2008

By A. K. Raji, E. F. Orumwense, M. O. Ojumu

This research paper introduces a novel passive method for ocean mining using an electricpowered robotic subsea dredging crawler designed to operate in various subsea conditions, including unstructured and rough terrain. The electric-powered robotic subsea dredging crawler is equipped with two driving tracks and features a complex assembly of tank tread chain link, tank tread idler wheels, tank tread sprockets, bronze bushings, motor hub, motor mount, and a 12-volt direct current motor. To evaluate the performance of the electric-powered robotic subsea dredging crawler, it was compared with existing ocean hydraulic exploration crawlers, such as MK3 ROST, in terms of drive performance on an inclined ramp with five angles of inclination (0°, 15°, 20°, 25°, 30°). The experiment aimed to determine the maximum velocity, torque, and efficiency of the crawler at different angles of inclination. The collected data were analysed and plotted using Python, and the effect of the electric-powered robotic subsea dredging crawler’s weight on its driving performance was also considered. The results of this study demonstrate a quadratic relationship between driving performance and inclination angle, which can be used to optimise the electric-powered robotic subsea dredging crawler’s performance for future ocean mining robot drive applications.

Oct 2, 2025

1. Books from Elsevier The folowing are available from Elsevier Applied Science, Crown House, Linton Road, Barking, Essex IGl 8JO, OK. . Driling wastes, edited by F.R. Engelhardt, J.P. Ray, and A.H. Gilam. 1989. 872 pp. £95. Geothermal resources, by R. Bowen. 2nd ed. 1989. 468 pp. £60. The fate and efects of oil in freshwater, edited by J. Green and M.W. Tret. 1989. 340 pp. £42. Mining and the freshwater environment, by Martyn Kely (with contributions by W.J. Alison, A.R. Garman, and C.J. Symon). 1988. 228 pp. £32. 2. Books produced by Metal Buletin The folowing are available from Metal Buletin PLC, Park House, Park Terace, Worcester Park, Surey KT47HY, England. Prices and data 1990. £41 (airmail). Foundry directory and register of forges 1989-1990. £52 (airmail). 2. Canadian Publications The folowing two publications are available from the Canadian Government Publishing Centre, Supply and Services Canada, Otawa, Canada KIA 059. Mining and mineral processing operations in Canada. Mineral Buletin MR 224. $23.70. Canadian minerals yearbook 1989. Review and outlook. Mineral Report 38. $47.95. Technology developments The Mintek Pyrosim Simulator Pyrosim is a computer program for the steady-state simulation of pyrometalurgical processes?.

Jan 1, 1990

By P. J. Foster

This paper summarizes a behavioural safety project undertaken in seven quarries in the UK in order to investigate its applicability as a means of raising the standards of health and safety in the UK quarrying industry. A behavioural safety methodology was developed and trialed at two quarry sites in the UK. During the study the number of unsafe acts and minor accidents had decreased and at one of the quarries there was a 95% reduction in the number of working days lost. It was then introduced at a further five sites of varying sizes and within this focused specifically on lone workers as well as behaviours that affected quality and environmental issues. Positive improvements were noted in most of these operations. The project also looked at the effectiveness of health and safety performance indicators. Here, the common lead and trailing indicators for both safety and health that are commonly used by industry were identified. In consultation with the UK quarrying industry these were then used to identify specific performance measurement criteria that can be used by the quarrying sector to measure performance. Following on from this, a quarry specific health and safety management system specification was developed for large and small quarries.

Jan 1, 2008

By T. Nghipulile, M. Moys, M. Bwalya, H. Simonsen

The quest for efficiency in comminution is an ongoing concern as comminution usually constitutes a major cost component in the metal production industry. Such improvements can be made by circuit optimization or development of more efficient equipment. A novel crusher, known as the rotary offset crusher (ROC), promises to deliver in this space. The ROC was invented in 2002 by Michael Hunt, Henry Simonsen, and Ian Sinclair, but failed to garner enough support to progress to production. The original design concept was recently rekindled, and a laboratory version of the crusher has been built and commissioned at the University of the Witwatersrand. The crusher is simple in design, with two cylindrical discs that are parallel to each other, and, as the name implies, there is an offset between the vertical axes of the discs. The top disc has a conical section on its lower face, and this creates a crushing zone between the opposite faces of the two spinning discs. Centrifugal motion transports particles through the crushing zone. Batch experiments have been conducted with quartz at various crusher settings (discs offset, rotational speed, and vertical exit gap) for various feed size distributions. The indications so far suggest that the disc speed is a key factor affecting the performance. Size reduction ratios as high as 11 were recorded from experiments with quartz at a speed of 830 r/min.

Jan 1, 2021

By C. V. O?Keefe

Volumetric flow and mass flow are two of the critical process parameters needed to understand and control flotation processes, with others being levels, densities, and metal analyses. Both volumetric flow and density measurements can be adversely influenced by entrained air, which will result in artificially high flow readings and artificially low mass flow calculations. Array-based instrumentation has been used successfully to accurately measure both volumetric flow of aerated slurry and the quantity of air entrained within the slurry. The latter measurement has been used to correct density measurements, thus providing an accurate mass flow calculation. A case study involving the use of this technology to measure both flow rates and air entrainment levels at Eland Platinum processing facility (concentrator) will be covered in detail. In addition, with certain traditional flow meters such as electromagnetic meters, erroneous volumetric flow rates can be recorded in the presence of paramagnetic or ferromagnetic material. The use of this array technology to avoid spikes in measurements due to steel fragments passing through the pipe will also be discussed.

Jan 1, 2012

By G. Song, X. Liu

The global coal industry has changed significantly in recent years. In this paper we analyse the coal production and consumption, imports and exports, and coal prices in China and other major coal-producing countries during the past four decades. The analysis shows that global coal production and consumption have declined over the last three years, in striking contrast to the continuous growth for most of the past 35 years. Australia, Indonesia, and Russia have become the world’s major coal providers, while China, India, and the USA, and Germany are the major coal consumers. The world’s, and China‘s, coal industry can be classified into four stages of development: the stable growth phase, stable phase, rapid growth phase, and high-quality phase. Coal prices rose in the world’s four major coal markets in 2016 after four consecutive years of falling prices. The elimination of overcapacity and production-optimizing operations in China could assist in achieving a demand and supply balance.

Aug 8, 2024