Johannesburg, South Africa
Johannesburg, South Africa

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Tupper G.B.,University of Cape Town | Govender I.,University of Cape Town | Mainza A.N.,University of Cape Town | Plint N.,Anglo American Platinum Ltd.
Minerals Engineering | Year: 2013

We describe a modelling approach to slurry transport in dynamic beds. Volume and time averaging are combined to obtain a dynamic replacement for the static Ergun equation. Solutions of the resulting dynamic equation are exhibited for a simple charge-motion model, which serves as the prototype for a practical slurry transport model. © 2012 Elsevier Inc. All rights reserved.

Gu Y.,University of Queensland | Schouwstra R.P.,Research Solutions | Rule C.,Anglo American Platinum Ltd.
Minerals Engineering | Year: 2014

Automated mineralogy methods and tools, such as the Mineral Liberation Analyser (MLA) and the QEMSCAN, are now widely used for ore characterization, process design and process optimization. Several case studies published recently demonstrate that large gains can be obtained through grinding and flotation optimization guided by automated mineralogy data. However, since automated mineralogy can only provide the information pointing to where the process gains can be made, it does not directly impact the production gain. Thus the question is often asked: how to value the contribution of automated mineralogy to process improvement at a particular plant. This appears to be a difficult question to answer. On close examination however, it is found that this is essentially a question of the value of information and this is reasonably well documented in various other industries. Hubbard, 2010, in chapter 7 "Measuring the Value of Information", dealt with exactly this type of problem. The value of information is the reduced risk of an investment and opportunity loss. The methods Hubbard developed can be applied to estimate the value of automated mineralogy, as well as metallurgical test work, both producing information that reduces the risk of investment.This paper first introduces Hubbard's theory on the value of information and how to measure it. It then applies his methods to estimate the value of automated mineralogy, using Anglo Platinum's fine grinding project as an example. In the end, a general model is developed to allow the simulation of the value of automated mineralogy in different mining operations constrained by different parameters. © 2014 Elsevier Ltd. All rights reserved.

Fourie H.,Anglo American Platinum Ltd.
Journal of the Southern African Institute of Mining and Metallurgy | Year: 2016

In mechanized mining, poor equipment efficiency (availability, utilization, productivity, and quality) can endanger the success of the operation. This case study will show how an initiative to improve equipment performance developed into a comprehensive turnaround plan for the mine that placed it in the forefront of performance achievement. As part of a company-wide review process, poor overall equipment effectiveness (OEE) was identified as a major reason for the mine not achieving its targets. A project to improve the OEE identified eight improvement areas (elements) that contributed significantly to the poor performances. Measurement metrics were determined for these elements, followed by determination of baseline and target (improved) key performance indicators (KPIs). Cost savings associated with the improved efficiencies were calculated and tracked throughout the project. The mine team determined the specific actions required to achieve the target KPI in each element. These were individuallydeveloped and managed like mini-projectswith allocated responsibility for delivery. The paper will indicate how this OEE improvement initiative triggered an improvement in almost all sections of the mine. Soon after launch, the initiative gathered momentum as the KPIs starting to improve. A visible tracking system exists at the mine and each employee can see the improvements and feel the success. The original eight elements were extended by five more, and the mini-projects grew as participants saw the success of the initiative. This paper concludes that through management and worker involvement, visible measurement and controls, and carefully chosen improvement elements, the mine was turned around. It is now achieving and exceeding its targets, and employee relations and motivation as well as safety have improved considerably. All of these achievements are reflected in the bottom line. © The Southern African Institute of Mining and Metallurgy, 2016.

Hadler K.,Imperial College London | Greyling M.,Anglo American Platinum Ltd. | Plint N.,Anglo American Platinum Ltd. | Cilliers J.J.,Imperial College London
Minerals Engineering | Year: 2012

In recent years, it has been shown that there is a clear link between froth stability and flotation performance. Air recovery is a measure of froth stability, and describes the fraction of air entering a flotation cell that overflows the cell lip as unburst bubbles. Studies have shown that air recovery passes through a peak as flotation cell aeration is increased. Furthermore, when a cell, or bank of cells, is operated at the air rate that yields this Peak Air Recovery (PAR), higher mineral recoveries are obtained, often for a higher concentrate grade. In this paper, the effect of froth depth on air recovery is discussed, particularly with regards to the interaction between air rate and froth depth. Using results obtained from an industrial experimental campaign, it is shown that, at a given air rate, air recovery passes through a peak as froth depth is increased. The froth depth at which PAR is obtained depends on the air rate; for example at lower air rates, the PAR froth depth will be shallower than at higher air rates. In order to operate at the highest air recovery, therefore, froth depth should increase as the air rate increases. Surveys were carried out at a single air rate and three different froth depths, in which air recovery increased with increasing froth depth. These results show that the lowest grades and recoveries were obtained when operating with the shallowest froth, which also yielded the lowest air recoveries, despite giving the highest mass pull. The highest mineral recovery was obtained when operating with the deepest froth. While the relationship between air rate, froth depth and PAR may be complex, the results presented in this paper underline that operating under conditions that yield high air recoveries is the best indicator for obtaining high mineral recoveries. © 2012 Elsevier Ltd. All rights reserved.

Le Bron K.B.,Anglo American Platinum Ltd. | Johnson R.A.,Anglo American Platinum Ltd.
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics | Year: 2012

Historically the extraction ratio on the UG2 reef when mining below Merensky reef pillars has been relatively low, even at shallow depths (less than 500 metres below surface). At depths in excess 1000 metres below surface, extraction is expected to be significantly lower, as a result of the panel collapses that occur on the face area of the UG2 panels mining underneath the Merensky pillars. Inelastic numerical modelling was performed to determine if the use of backfill could improve this extraction ratio and at what depth below surface it is required. © 2012 Taylor & Francis Group, London.

Le Bron K.B.,Anglo American Platinum Ltd. | Johnson R.A.,Anglo American Platinum Ltd.
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics | Year: 2012

An area of shallow UG2 reef underneath existing surface infrastructure has been left un-mined. Permission from the South African Government Department of Mineral Resources must be obtained before the ground can be mined. An underground geotechnical assessment and numerical modelling was completed to determine the influence of mining this ground on the stability of this infrastructure. The deformation criteria (strain and tilt) for different surface structure categories (Stacey and Bakker, 1992) were used in the analysis. © 2012 Taylor & Francis Group, London.

Smith G.L.,Anglo American Platinum Ltd.
Journal of the Southern African Institute of Mining and Metallurgy | Year: 2012

The fundamental challenge facing mineral and metal companies is how to create sustainable value while operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to drive definition of the optimal technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near- and longer-term business environment shifts, i.e. a production mix that allows variation of output to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the concept of strategic long term planning. The core elements of strategic long term planning in the metals and minerals industry, and the relationship between them, are expanded. The strategic long term planning framework is a logic construct that enables delivery of an optimized, strategically-aligned business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes to align decisions and actions on a cyclical basis. © The Southern African Institute of Mining and Metallurgy, 2012.

Nelson L.R.,Anglo American Platinum Ltd.
TMS Annual Meeting | Year: 2014

The historical progression in installed electric furnace smelting capacity of some 1650 calcium, chromium, manganese, nickel and silicon ferro-alloys furnaces is reviewed. Key increases in the inherent installed electrical capacity, often achieved through uprating furnaces, are identified. Possible factors facilitating such advances are explored, including: specific process engineering and pyrometallurgical enhancements (e.g., improved control over the consistency, size and chemical form of raw materials, extents of preheating and pre-reduction delivered into the furnace; and patterns of feed distribution); furnace electrical configuration (AC or DC; immersed, submerged-, shieldedor open-arc); form of electrode (graphite, self-baking or composite); furnace configuration (circular or rectangular; closed or open and 1-, 3- or 6-electrodes); better engineering and equipment designs (e.g., high-intensity cooling) and state of furnace electrical and metallurgical control systems. A view is presented on the prevailing state of evolution of the Mega-scale in ferro-alloy smelting and opportunities for still further improvements.

Rule C.,Anglo American Platinum Ltd. | De Waal H.,Xstrata Technology
METPLANT 2011 - Metallurgical Plant Design and Operating Strategies | Year: 2011

In 2003, Anglo Platinum, in a joint development with Xstrata Technology, installed the world's first 10 000 litre IsaMill™ in a concentrate regrind duty at the Western Limb Tailings Re-treatment Plant. The success of that installation was the enabling event for Anglo Platinum to proceed with a substantial investment in horizontal stirred milling technology. Since 2006 an additional three IsaMills™ in concentrate regrind duties and a further 18 IsaMills™ in the more technically challenging coarse grinding mainstream applications, have been commissioned in group Concentrator operations - bringing the total number of IsaMills™ installed in Anglo Platinum plants to 22. A collaborative approach between Anglo Platinum and Xstrata Technology towards improving milling efficiency and reducing operating costs, through internal mill component wear optimization and operating recipe development, has resulted in further improvements in the overall success of IsaMills™ in the flow sheets of many Anglo Platinum operations. The addition of IsaMills™ in the Anglo Platinum flow sheets has improved plant PGM recoveries by as much as 5%. This paper explores the improvements made to the IsaMills™ flow sheet and mill internal design and shares some of the operating experience with IsaMills™ technology in Anglo Platinum.

Doyle B.A.,Anglo American Platinum Ltd.
Journal of the Mine Ventilation Society of South Africa | Year: 2012

This paper describes various Occupational Hygiene initiatives presently being undertaken at Anglo American Platinum. These initiatives vary between corporate systems generated in order to obtain Group exposure overviews and other practical innovations that add value to the organization and stimulate knowledge and "thinking out the box" skills. Corporate functions require the ability to have a system in place where a Group wide overview can be obtained on the status of the implemented systems of Occupational Hygiene measurements. These overview systems serve to establish a high level of compliance assurance of together with allowing a corporate summary of the status quo on personal exposure measurements. Based on these outcomes, remedial action together with other governance issues can be identified, developed and implemented. Four other interesting initiatives are in progress. These are projects dealing with the possible quantification of gassing cases, the use of a practical noise measuring instrument fitted to a hard hat, an electronic solution to cope with the requirements of the DMR 389 form dealing with records of hazardous work and allowing gas testing/monitoring results to be more accessible. It is stimulating and rewarding to undertake projects such as these as, apart from adding value to the organization and its employees, technical knowledge is challenged and the knowledge base is increased.

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