SAIMM Journal - February 2016 Contents Journal Comment—Mining Business Optimization 2015 by M. Woodhall President's Corner—Cooperative human social behaviour by R.T. Jones Obituary—Reflections on the life of Robbie Robinson by R.D. Beck Papers – Mining Business Optimization Conference Post-pit optimization strategic alignment by M.F. Breed and D. van Heerden This paper describes and discusses the selection of an alternative cut-off grade as a strategic intervention. It involves changing the cut-off grade, and effectively increasing the head grade to gain a strategic advantage with a clear understanding of the financial value impact. Impact of discount rates on cut-off grades for narrow tabular gold deposits by C. Birch The purpose of this study was to establish the impact of discount rates on cut-off grades for narrow, tabular gold deposits. A simple financial model was created that links the ore flow, block listing, and the cash flow, allowing the cut-off grade to be optimized considering how the cost -of -capital and chosen discount rate affect the cash flow. The results from the model were found to be comparable to the current cut-off grades obtained from the mine's proprietary optimizer program. Business optimization for platinum mining projects and operations by P.J. Petit This paper describes a mining case study that applies business optimization as a methodology to optimize both short- and long-term targets. Business optimization increased the NPV by 14.7% by challenging conventional decision-making associated with maximizing business value by including environmental externalities within the life of project A simultaneous mining and mineral processing optimization and sustainability evaluation prepared during a platinum project prefeasibility study by S.F. Burks The case study consisted of a review of the prefeasibility study designs and cost estimates for a platinum group metal project in South Africa. Value chain optimization and sustainability studies were carried out simultaneously to identify potential value uplifts and guide the owner's team as it moves into the feasibility study phase of this project. Application of manufacturing management and improvement methodologies in the southern African mining industry by J.O. Claassen A study was conducted on the business management and improvement methods used at 22 operating mines in southern Africa. It is argued that successful mining business management and improvement depends on management's ability to effectively deal with mining industry-specific requirements, the integration of the geology- mining-plant system, and the implementation of systemic flow-based principles in all aspects of mining. Monitoring ore loss and dilution for mine-to-mill integration in deep gold mines: a survey-based investigation by L. Xingwana The purpose of this study was to understand how ore loss and dilution affect the mine call factor with the aim of subsequently improving the quality of ore mined and the feed to the mill. A case study revealed that ore fragmentation, underground accumulation of ore, and dilution have a significant influence on the mine call factor and mine output Papers Of General Interest Anomaly enhancement in 2D electrical resistivity imaging method using a residual resistivity technique by A. Amini and H. Ramazi A study was carried out in a karstic area in western Iran to detect the location and geometry of probable cavities by conventional resistivity inversion and residual resistivity (RR)-based inversion. The results showed that the anomalous zones are better highlighted in the RR-based inversion images compared with the conventional inversion images. Determination of mineral matter and elemental composition of individual macerals in coals from Highveld mines by R.H. Matjie, Z. Li, C.R. Ward, J.R. Bunt, and C.A. Strydom A number of conventional and advanced analytical techniques were integrated and cross-checked to provide a detailed characterization of coals from the Highveld coalfield in South Africa in order to better understand the mineralogical and chemical properties of the individual coal sources that are blended as feedstocks for combustion and carbon conversion processes. Testing for heterogeneity in complex mining environments by J.O. Claassen A study performed at several operating mines suggests that the impact of heterogeneous or variable geological, mining, and plant processing environments on overall mining value chain performance may not be a key focus area at these operations. The findings reflect a high relative variability in the geological and processing environments and the mining operator's inability to effectively deal with the sources and consequences of variability. A focus on heterogeneity in complex mining operations may significantly enhance overall performance. Stochastic simulation of the Fox kimberlitic diamond pipe, Ekati mine, Northwest Territories, Canada by L. Robles-Stefoni and R. Dimitrakopoulos Two multiple-point simulation methods were tested for modelling the geology of a diamond pipe at the Ekati mine. The validation of the simulation results showed a reasonable reproduction of the geometry and data proportions for all the geological units considered. Study of the pyrolysis kinetics of Datong coal using a sectioning method by R. Du, K. Wu, X. Yuan, D. Xu, and C. Chao A sectioning method was used to overcome certain shortcomings of the traditional methods used in studying the pyrolysis of coal. The temperature range was divided into three intervals, and three corresponding models of reaction established to study the different stages of the pyrolysis process. Effect of crushing on near-gravity material distribution in different size fractions of an Indian non-coking coal by S. Mohanta, B. Sahoo, I.D. Behera, and S. Pradhan Two numerical indices, namely 'near gravity material index' and 'index of washability', are used to quantify the distribution of the near-gravity material in different density classes and to evaluate the degree of difficulty involved in the coal washing process. Regards Kelly Matthee Journal & Subscriptions Co-Ordinator Telephone: +27 11 834 1273 Facsimile: 086 585 2901 E-mail kelly@saimm.co.za |