Search Documents

By T. C. Huber

The southern African region has a high concentration of mineral resources and supplies much of the world?s platinum demand. As a result, the international community watches South Africa to understand the impact of supply on global markets. An analysis of supply certainty and risk plays a key role in the future of growing demand in various sectors. The southern African platinum industry experienced substantial growth in the early part of the 21st century, resulting in bullish forecasts for growth during the period of 2000?2006. However, southern African platinum producers saw a significant drop in production over the following three years as a result of many dynamic factors in operations and the global economy. Between 2006 and 2009 there was a million-ounce shortfall between forecast and actual production. This was raised as a concern at the Fourth International Platinum Conference in 2010 by Stephen Forrest during his keynote address, specifically regarding the lack of understanding in the market of the causes of this shortfall and any action that was being taken to address them. This paper reviews publicly available information in the media and corporate reports and communications for the period January 2006 to December 2009. In addition, several interviews were held with key stakeholders in the industry to provide further perspective. The paper then highlights the main reasons that are reported to have affected the loss in production over the period and discusses the possible implications of the information that the mining industry does and does not disclose regarding platinum supply.

Jan 1, 2012

By X. M. Prévost

The reassessment of coal reserves has become a matter of urgency and has come as a result of the present situation of the industry, in the context of globalized coal economies, as well as new mining legislation and the advantages and difficulties of domestic coal suppliers. The de Jager report concerning coal reserves, released twenty years ago, can no longer be used as an estimate for accurately forecasting South Africa’s future coal production. The new reserve and resource study will promote the diversification of energy sources and provide a clearer view of the future of coal mining in the country. With plans to increase South Africa’s coal export capacity to approximately 84 million tons by 2005, it is uncertain whether the country really has sufficient reserves to meet this expansion, as well as satisfy the projected increase in inland demand. The face of South Africa’s coal industry and by association, the economy of our coal-dependent country, are both set to change. This is mainly due to factors such as the demise of most of the large collieries over the last approximately twenty years, growing numbers of economic empowerment producers, the emergence of strong competition in the export market, the dawn of Clean Coal Technologies (CCTs) and the Kyoto Protocol The paper will attempt to dispel some of the current myths about coalfields and reserves and highlight potential areas of high quality coal reserves, available mainly to new entrants in the industry. Keywords: Central Basin, Clean coal technologies, Coal combustion, Coal exports, Coalfields, coalLink, Coal reserves, Coal resources, Coal processing, Colliery, Economic empowerment, Discards, Fluidized bed combustion, Low-ash coal, Metallurgical coal, Power generation, Pulverized fuel, Reserve blocks, Richards Bay Coal Terminal, Run-of-mine production, Saleable production, SAMREC Code, South Dunes Coal Terminal, Steam coal, Synthetic fuels.

Jan 1, 2003

By F. H. Deist, M. P. Roberts

"The Collieries Research Laboratory of the Chamber of Mines of South Africa is developing a coherent system of programs to aid in the full spectrum of activities arising in the planning of new as well as operating mining enterprises. It is the purpose of this paper to describe the design and application of two subsystems in the complex.One of these subsystems is an initial version of a production simulator. This program draws upon a model of a mining enterprise and simulates the operational and financial aspects of a set of alternative mine production plans.These plans are specified in terms of proposed sequences of operations. Details such as reserves, production rates, resource requirements and so on, are taken from the model.Physically, the model takes the form of a cross-referenced data base, maintained by means of a general file maintenance system which is another subsystem described.The paper concludes with a description and analysis of the first practical application of the two programs."

Jan 1, 2014

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 P. W. J. Delport, E. Du Toit

Investing in a mining venture can be risky and stakeholders need transparent, unbiased reports to understand the Mineral Resources and Mineral Reserves a mining company holds. Readability and textual choice can be used consciously to manipulate perceptions, or it can be done unconsciously. This exploratory study investigates the readability and textual choice of supplementary Mineral Resources and Mineral Reserves Reports of companies listed on the Johannesburg Stock Exchange. The results indicate that narrative manipulation occurs in these reports through word choices that make the reports difficult to read, as well as specific narrative selections. This reduces the informational value of the reports. The results of the study will be useful to various stakeholders, such as mining company management, investors, investment specialists, financial analysts, and even employees and the general community, who all use these reports to make important decisions. It is also useful for the preparers of the Mineral Resources and Mineral Reserves Reports, Competent Persons, and other technical specialists to be aware of readability and that certain textual choices can affect the interpretation of these reports. It is recommended that bodies such as the JSE and the SAMREC and SAMVAL Code committees consider adding a plain language requirement to regulations, guidelines, and codes to ensure transparent, unbiased, and objective reports.

Mar 1, 2021

By B. M. Thethwayo

Graphite blocks are currently used in the concentrate - slag zone in primary PGM smelters, and can possibly be extended to the matte zone. This project evaluates the interaction between synthetic matte and graphite blocks on a laboratory scale. Static crucible tests were performed where graphite crucibles (prepared from standard and high-grade graphite) were filled with synthetic matte (27.7 per cent S ? 46.1 per cent Fe ? 17.0 per cent Ni ? 9.2 per cent Cu) and heated to 1550°C for different time periods (1?5 days). Matte penetration was evaluated using a SEM, while graphite dissolution was evaluated by measuring the carbon content of the matte with a LECO carbon analyser. Matte penetrated into standard grade graphite up to approximately 2 mm, while matte infiltration into the high grade graphite was limited to the immediate hot face. The saturation solubility of graphite in the synthetic matte at 1550°C was 0.43 per cent. Copper, iron, nickel, and sulphur were detected in an accretion that formed in the water-cooled part of the furnace. This accretion consists of mainly Cu-S and Cu-Fe-S based phases.

Jan 1, 2012

High pressure grinding technology has gained further interest in various industries. So far in the mining industry, machines are in operation in diamond mines and iron ore applications. In gold and copper ore processing, test work has been conducted showing considerable operational and process benefits. Similar benefits can be expected from HPGR applications in the platinum industry due to the preferred ore breakage along grain boundaries, thus liberating the PGE particles. This paper will provide an update on the state of high pressure grinding roll technology. Developments in the design of high pressure grinding rolls, for minimized maintenance requirements and availability just as high as conventional mills, will be presented. Plant flow sheets and concepts will be discussed, which allow for a reduction of capital and operating cost in comparison to existing two-stage milling circuits.

Jan 1, 2004

By F. Qunfei, W. Laijun, X. Lyu, A. Cosmos, L Huijuan, Z. Jinggang, G. Yao

In this paper, four cyanide-utilising bacteria strains were isolated from a gold mine tailings pond, in the Hexi gold mine (Shandong), China. Based on the analysis of 16S rRNA gene sequence, four strains were identified as Aeromonas hydrophila strain C1, Bacillus mojavensis strain C3, Shewanella oneidensis strain C2, and Aeromonas media strain C4. Based on the cyanide detoxification efficiencies results of the four strains, Bacillus mojavensis C3 had the highest detoxification rate and was selected to assess its efficiency to detoxify cyanide in gold mine tailings at different pH (9.5, 10.5, and 11.6) using cyanide as the sole carbon and nitrogen sources. Strain C3 was capable of detoxifying 46.5mg/L of cyanide-containing gold mine tailings at all tested pH ranges at 30oC, 196 rpm after 15 d. The amounts of cyanide detoxified were 87.5%, 84.1%, and 73.5% at initial pH 9.5, 10.5, and 11.6, respectively. The highest cyanide detoxification was observed at pH 9.5. The viable cells growths in the samples were 5.7E+09CFU/mL, 4.9E+09CFU/mL, and 2.7E+09CFU/mL at pH 9.5, 10.5, and 11.6, respectively. Free ammonia concentrations were observed as a byproduct of the biodetoxification process. The residual ammonia concentration in the sample was observed at 0.35 mg/L, 0.33 mg/L, and 0.62 mg/L at pH 9.5, 10.5, and 11.6, respectively. The highest residual ammonia concentration was noticed at pH 11.6. The amount of cyanide removed by mixed culture strains C3 and C4 was 94.6% and showed a residual free ammonia concentration of 2.6mg/L, as biodetoxification byproduct after 120 h. The pure culture Bacillus mojavensis strain C3 and its mixed culture strains exhibited higher potential to detoxify cyanide-containing gold mine tailings at alkaline pH values and could be cultivated to detoxify gold mine effluents at large-scale. Keywords: Bacteria strain, cyanide, detoxification efficiency, gold mine tailings

Jan 1, 2020

By D. Marcotte, R. V. Dutaut

"In mineral resource evaluations, geostatistical methods known as global change of support allow prediction of the theoretical histogram and gradetonnage curves prior to interpolations or simulations of grades. Two methods commonly used by professionals to guide the choice of interpolation parameters and assess results are the discrete Gaussian model (DGM) and the indirect lognormal correction (IndLog). These models rely upon an estimate of the dispersion variance of the blocks, which is derived by numerical integration of the variogram model over a discretized block. Due to difficulties in obtaining well-formed traditional experimental variograms (especially in the presence of outliers and limited clustered data), many professionals prefer to use ‘normalized’ variograms such as correlogram (non-ergodic variogram), pairwise-relative, or variogram of the normal score transform. A series of simulations with different grade distributions and variogram models are used to assess the performances and robustness of the various variogram estimators with respect to the DGM and IndLog global change of support. Our results show that the traditional variogram, the correlogram, and normal score variogram have better performances, compared to pairwise, for both DGM and IndLog. Moreover, DGM provided better results than IndLog for the grade distributions that are not strictly lognormal. These findings provide valuable guides for geostatistics practitioners. IntroductionWhen reporting resource estimates,practitioners are required to follow generalstandards described in the NI43-101 (CIMguidelines), JORC, or SAMREC codes. One cangenerally recognize three main parts directlyrelated to the block model:•,Pre-processing: exploratory data analysis (EDA), domaining, capping, compositing, declustering, variography•,Processing: block size, neighbourhood, interpolation types (linear or nonlinear)•,Post-processing: classification, reporting.Pre-processing aims to simplify and strengthen the processing step. Ideally, domaining, capping. and compositing is aimed at defining a single homogenous population. During the processing phase, a common practice is to use a block size corresponding to the planned selective mining unit (SMU). In most precious metal deposits (gold, notably), the SMU size is frequently smaller than the recommended half data spacing (Journel and Huijbregts 1978), resulting in high estimation variance and either a high degree of smoothing if the regression slope is managed or a high degree of conditional bias if it is not. Most actual resource estimates are made using block sizes between one-quarter to one-sixth of the average data spacing, sometimes even smaller. In addition to the block size, the interpolation choices for the neighbourhood selection and interpolator (e.g. inverse distance (ID) or ordinary kriging) are often based on the Qualified Person’s (the QP) experience and some basic validation plots that often do not consider the conditional bias (e.g. trends or SWATHs plots, which are designed to compare two sets of population using a one-dimensional graph)."

Jan 1, 2018

By V. Sheikhzadeh, S. M. H. Haddad, M. Saghaeian, N. Esmaeili, R. Hejazi

One of the most significant features of iron ore concentrate (pelletising feed) is the specific surface area (SSA) that affects the achievement of desirable pellet properties. There are various methods to determine this parameters and currently, the most common is the Blaine air permeability method. However, due to the simplified assumptions including spherical and identical particles and 50% bed porosity, the Blain test does not provide accurate results. In fact, these two suppositions are far from reality. In this research, comparison of SSA measurement ways are investigated, containing laser diffraction testing and Blaine air permeability, on samples with different SSA, obtained from Ball mill and high pressure grinding rolls (HPGR). The output data showed that the calculated amounts of SSA by means of laser analysis were far greater than any other one. Furthermore, in the same results of Blaine air permeability tests on samples comminuted by different grinding methods, it was observed that the SSA figures from the laser diffraction method for HPGR products were almost 800 units greater than Ball mill ones. Keywords: Pelletising feed, specific surface area, Blaine air permeability, laser diffraction testing

Jan 1, 2020

By T. S. Golosinski

The paper reviews current status of online education related to mining, and reports on the online Master of Engineering programme in Mining Engineering that is offered at the University of Missouri-Rolla since 2001. Keywords: Online education, learning, teaching, mining engineering, mining education online

Jan 1, 2003

By P. Saayman

The mining industry has much potential for automation. A great deal of work has been done on this subject and is still ongoing. With automation comes the possibility for optimization, because more information is available and actions can be repeated with more accuracy. This paper looks at possible solutions to the problem of optimizing the autonomous vehicle dispatch system in an underground mine. Possible optimization strategies are evaluated using a simulated environment. The majority of the results indicate that improvements on current methods are possible. Keywords: mining automation, simulation, vehicles, dispatching strategy, optimization.

Jan 1, 2006

The first annual student prizegiving function of the South African Institute of Mining and Metallurgy was held in the Dorothy Susskind Auditorium, University of the Witwatersrand, on Thursday, 26th May, 1977. The address (see opposite page) was given by Dr M. G. Atmore, a director of Anglo American Corporation and Vice-President of the Institute.

Jan 1, 1977

By Sylvie Poirier

Researchers at Natural Resources Canada (NRCan) CANMET Mining and Mineral Sciences Laboratories (CANMET-MMSL) and Mining Technologies International (MTI) have designed and built a hybrid diesel-electric mining loader that is the first of its kind to be developed for underground mines. Diesel equipment is popular because of its mobility and most mining operations are reluctant to replace it with tethered electrical equipment despite the obvious elimination of diesel contaminants and significantly lower heat generation (? 35% of an equivalent diesel). However, a diesel-electric vehicle, being currently evaluated by CANMET-MMSL, could be beneficial. In this unit, a constant load diesel generator feeds batteries which, in turn, powers electrical motors that drive the equipment. In a hybrid diesel-electric unit, the constant load diesel generator can be optimized for minimal emissions and hence lower dilution air requirements. This paper will present the project status and the anticipated benefits for mining operations through the application of this technology.

Jan 1, 2008

By B. I. Matshediso, J. Kaavera, E. Shemang, T. K. Dintwe, L. S. Teseletso, K. Fichani

The minerals sector continues to draw attention from policy makers who would want to see both old and new mineral projects add value to the minerals in the host country. The current technological development in the leaching of manganese oxide ores to produce a high-purity manganese sulphate monohydrate, a compound that is used in the manufacture of batteries for electric vehicles or long-life storage cells for the renewable energy market, has led to junior mining companies spearheading this technology in new projects across the globe. In this paper, we researched the high-purity manganese sulphate monohydrate project pipeline and used projected production volumes and C1 cash costs to construct the industry supply curve for six projects, including the K.Hill project owned by Giyani Metals Corporation near Kanye, in the southern part of Botswana. The aim was to determine the ideal conditions that would provide a comparative advantage for further local value addition to high-purity manganese sulphate monohydrate and to the end user product. The results showed that while the estimated C1 cash costs would place the K.Hill project as the second highest cost producer from among five projects, it would nonetheless have healthy profit margins due to the high projected price of high-purity manganese sulphate monohydrate. The study recommended policy options, which, if implemented, could further encourage the exploitation and value addition of battery metals in Botswana.

May 27, 2025

By T. Nyakudarika

The Unki Platinum Mines concentrator, employing an MF2 circuit configuration which includes fully-autogenous primary milling of run-of-mine (ROM) ore, was commissioned in November 2010. The project was Anglo American Platinum?s first PGM concentrator in Zimbabwe and would form a significant contribution to the group?s platinum production. The project financials demonstrated that the project was operating-cost sensitive. After reviewing the metallurgical testwork, mineralogical examinations, and the history of similar operations, it became apparent that the Unki ore characteristics rendered it amenable to autogenous milling. The primary ball mill, structurally designed for 30 per cent steel load, could be operated at the required initial phase throughput with fully-autogenous primary milling, realizing savings in both power requirements and grinding media consumption. The original mill sizing had been done with fully-autogenous milling in mind, but allowing for flexibility and mitigation in case of varied mining fragmentation. Since attaining steady state, target grinds have been achieved. This paper looks at the Unki ore characterization programme, design considerations, and the operational and control philosophy for a successful comminution circuit, and discusses the design to produce a flexible, low opex, mitigated comminution and overall MF2 flowsheet that is easily expanded in line with the potential for optimum exploitation of the orebody.

Jan 1, 2012

Introducing your Council. Mr J. S. Freer, Pr. Eng., after matriculating at Michaelhouse in 1944, obtained a B.8c. degree in chemistry and biology (1948) and a B.Sc. (Hons.) in chemistry (1949) from the University of the Witwatersrand. Mr G. C. Thompson matriculated at Dale College in 1951. He then attended the University of the Witwatersrand, where he obtained a B.8c. (Min. Eng.) in 1959. Mr P. T. Fewell was born and educated in the United Kingdom. After obtaining the degree of Bachelor of Engineering (Mining) in 1958 at Sheffield University, he emigrated to South Africa. DtP. R. Jochens, Pr. Eng., has been a member of Council since 1974, serving as President in 1980-1981.

Jan 1, 1984

By P. Valicek

Anglo American Platinum Limited is constantly striving to improve safety and productivity. There are many different initiatives taking place within the organization in order to ensure continued safe operation and profitable ounces for the future. One of the opportunities and potential growth areas that has been identified and is being explored is that of mechanization. In order to do this, the approach that has been adopted by Anglo American Platinum is to fully understand and analyse the current mechanized mining methods. Once each configuration is fully understood, the method can then be optimized and new mining technologies and systems can be developed to overcome the current shortfalls. This paper will discuss a methodology that was developed by Anglo American Platinum (in conjunction with Cyest Corporation) and adopted to optimize the mechanized mining layout and fleet configuration, and will also present the final findings of the study. Due to the impracticability of piloting every possible option in the workplace, extensive modelling and simulation exercises were conducted to determine realistic parameters for productivity and value. The study resulted in a full understanding of mechanized mining systems and their associated layout. From the results of the study a mining / logistic layout was developed which highlighted the following opportunities: 1. Create safe operations through the reduction of personnel in the ?high-risk zone? of stopes 2. Separate machines and personnel by use of remotely operated machines 3. Create focused mining on primary development from the production stoping, thus having dedicated teams on development and stoping. 4. Develop primary development ahead of the stoping activity. This enables: a) Understanding of the geology and subsequent implementation of the correct b) technology (?fit-for-purpose?) required to mine that area based upon this geological knowledge c) Ability to install tipping points ahead of stoping, creating ?immediate stoping reserves?, thus increasing flexibility and reducing production risk d) Improved productivity by having adequate faces available and reduction in re-development to establish faces. 5. Quicker return on Investment due to recovering revenue from ?on-reef development? 6. The layout allows flexibility between stope sections enabling better ?resource sharing? 7. Optimize the long-term ratio of machine makeup of the fleet in relation to the production outputs 8. Creates an agile mining layout allowing rapid response to market pressures. The findings and work presented in this paper is currently being implemented at different test sites within Anglo American Platinum and will demonstrate that improved safety and productivity can be achieved through the adoption of mechanization.

Jan 1, 2012

By T. Bui, T. Wallmach, S. B. Blancher, A. Back, M. Pierre, V. Delarue, A. Kanzari

This study investigates nickel laterite porosity and its impact on geometallurgical modelling. We performed a detailed mineralogical study on a set of Ni-laterite samples originating from New Caledonia. Samples were analysed after heavy liquid separation by automated SEM (QEMSCAN®). Laboratory and QEMSCAN® modelling results do not correlate well. Ideal physical mineral properties such as mineral densities used in QEMSCAN® modelling do not match the actual physical densities of minerals. The presence of empty or water-filled pores can represent important amounts in minerals and change the overall density of a particle. An adequate modelling of real density separation of minerals and particles should consider the water-filled pores. The first step towards a better simulation was to integrate pores larger than 10 μm in diameter filled with water (density of 1 g/cm3) in the QEMSCAN® database. The results approached, but did not match the physical laboratory results. The second step was to identify nanometer to micrometer sized pores, which could not be identified by QEMSCAN®. It was possible to identify nanometric pores in enstatite, Fe-oxides, serpentine, talc and quartz, and radial aggregates of fibrous Fe-oxyhydroxides with high resolution SEM (HR-SEM). The quantification of those micro-sized pores was performed on 2D HR-SEM images using image-processing techniques developed in Python to calculate the nanometer to micrometer scale pores in each mineral. Despite the limitation of converting 2D imaging into 3D objects, in our case pore sizes and porosities, we were able to calculate a mean value of porosity for each mineral. The integration of this porosity in the calculation of particle densities yielded a good match between the QEMSCAN® model and the laboratory experiment results. Despite the complexity of a strongly weathered material, such as Ni-laterites, a good knowledge of the ore makes it possible to build reliable processing models. Keywords: Mineralogy, geometallurgy, nickel laterites, SEM, QEMSCAN®, porosity, density

Jan 1, 2020

By J. R. L. Read, A. N. Ogden

This paper describes mining industry funded research that is being undertaken to address the critical gaps and uncertainties in our knowledge so that we can develop new approaches and create more effective ways for predicting the reliability of rock slopes in large open pit mines. It is envisaged that this research will not only lead to more effective pit slope design but further reduce the potential for unforseen geotechnical risks by enabling the geotechnician to communicate the risks more effectively with management and to optimise site specific control measures. To achieve this, several research tasks are in hand. The first is to accurately represent the structured rock mass with a 3D computer model (Siromodel) that creates polyhedral blocks from structural distribution data characterised by position, orientation and persistence. Siromodel is being coupled with particle flow and other numerical codes to evaluate how the structured rock mass deforms in the stress environment of an open pit and how a candidate failure surface may propagate through the dilating rock mass along the path of the least shear and/or tension resistance. A beta version of the Siromodel software has been distributed to 20 Sponsor mine sites for technical evaluation. The end state is to develop methods of analysis that characterise the reliability of a described candidate surface, and the probability of the candidate surface propagating to failure, recognising that the rock mass strength may well be defined in a different way than before.

Jan 1, 2006