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| PAPERS – DANIE KRIGE GEOSTATISTICAL CONFERENCE Resource estimation for deep tabular orebodies the Anglogold Ashanti way by T. Flitton and R. Peattie AngloGold Ashanti (AGA) utilizes a technique termed macro cokriging (MCK), which entails the estimation of mixed support size data together with the application of four-parameter distribution models. The gold value estimation for the Carbon Leader Reef (CLR) on the AGA TauTona Mine is used in this paper as a case study of the technique and to demonstrate its effectiveness through production reconciliation. A test of the appropriateness of the LUC technique in high-nugget Birimian-style gold deposits by E. Maritz A study was undertaken to determine how valid the predicted grade patterns of a typical Birimian- style gold deposit, with high nugget effect and strong short-range variability, might be expected to be. The results showed a satisfactory correlation between the direct kriging ranking of the smallest mining units (based on sparse data) and the grade control model ranking. The LUC technique is therefore considered to be useful for this type of deposit. The practical implementation of uniform conditioning at AngloGold Ashanti African Operations, and a case study as applied for potential underground mining at Nyankanga pit, Geita gold mine, Tanzania by V. Govindsammy This paper outlines the use of uniform conditioning (UC) to provide a robust estimate for use in underground mine planning and published Mineral Resource statements. The process and validation techniques employed for UC are discussed using a case study from an orebody in Tanzania. The UC model, in spite of the inherent lack of local spatial accuracy, can be used to estimate the potential underground stopes with a lower error of estimation than other techniques. Construction of an expert-opinion-based virtual orebody for a diamondiferous linear beach deposit by J. Jacob and C. Prins This paper demonstrates how expert opinion is used to generate a composite probability map for diamond concentration using a greyscale hand-sketching technique. The resultant grade simulation is used to test different sample scenarios and is a first step towards determining an appropriate sampling strategy for the target area. The basic tenets of evaluating the Mineral Resource assets of mining companies, as observed through Professor Danie Krige's pioneering work over half a century by W. Assibey-Bonsu This paper provides a summary of the first Professor Danie Krige Memorial Lecture that was held in 2014, and is a testimony to a man who became a giant not only in the South African mining industry, but indeed worldwide. When should uniform conditioning be applied? by K. Hansmann This paper presents an overview of uniform conditioning and localized uniform conditioning, with discussions around results of the research work that was carried out. PAPERS OF GENERAL INTEREST Optimizing open-pit block scheduling with exposed ore reserveby J. Saavedra-Rosas, E. Jelvez, J. Amaya and N. Morales An orebody is often comprised of several thousands or millions of blocks and the scheduling models for this structure are very complex. In this work, a set of new binary variables, representing which blocks can be declared as exposed ore reserve, in addition to the extraction and processing decisions, is introduced. The model has been coded and tested in a set of standard instances, showing very encouraging results in the generation of operational block schedules. Increasing the value and feasibility of open pit plans by integrating the mining system into the planning process by N. Morales and P. Reyes A model is presented that considers the mine production scheduling coupled with the mining system at different levels of detail. It is shown that it is essential to include the whole range of considerations, variables, and constraints in the planning process. An improved meta-heuristic approach to extraction sequencing and block routing by Y.A. Sari and M. Kumral A new approach to mine production scheduling based on a meta-heuristic approach is proposed. Different meta- heuristic techniques and their applications to mine production scheduling are discussed, and a case study presented that demonstrates how a meta-heuristic approach takes a sub-optimal solution and improves it over time. Multiple cut-off grade optimization by genetic algorithms and comparison with grid search method and dynamic programming by E. Cetin and P.A. Dowd A description of the general problem of cut-off grade optimization for multi-mineral deposits is presented, together with an outline of the use of genetic algorithms, the grid search method, and dynamic programming for optimal cut-off grade schedules for deposits with up to three constituent minerals. The various methods are compared by assessing the results of the implications involved in using them. In situ mining through leaching: experimental methodology for evaluating its implementation and economic considerations by C. Bahamondez, R. Castro, T. Vargas, and E. Arancibia A laboratory model and an experimental protocol were developed to evaluate the implementation of the in situ mining method for copper sulphide deposits and to provide an estimate of the economic value of the method in comparison with conventional mining. Coal quality management model for dome storage (DS-CQMM) by M.A. Badani-Prado, V. Kecojevic, and D. Bogunovic A custom-made, integrated coal quality management model was developed for dome storage (DS-CQMM) at a surface coal mine in the southern USA. The model can be helpful if, for example, the mine needs a specific tonnage with a specific quality in a relatively short time frame, and for blending the coal incoming from the mine with the coal retrieved from the dome. Regards KELLY MATTHEE JOURNAL & SUBSCRIPTIONS CO-ORDINATOR Telephone: +27 11 834 1273 Facsimile: 086 585 2901 E-mail kelly@saimm.co.za | |
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