Wireframe-Free Geological Modelling – An Oxymoron or a Value Proposition?

摘要

Effi ciency demands that mine geologists devote the most time to tasks where they can have thernbiggest effect on production. One of the most time-consuming tasks is geological interpretation ofrnthe orebody and turning this into a block model for the planning engineers.rnThe current best practice for mines that require a geologically constrained resource modelrninvolves capturing the interpretation of geologists as three-dimensional (3D) wireframes.rnHowever, there is signifi cant overhead in the production of valid wireframes from sectional andrnplan interpretations. This overhead consists of the mundane tasks of digitising polylines, thenrnbuilding 3D wireframes and validating them. While software can simplify this task, the currentrnprocess is not the best use of a geologist’s time. Under time pressure exerted by planning engineersrnand the time required for modelling from polylines, geologists are forced to roll-up the presence ofrnother elements or impurities into the interpretation and encode them in the polylines, even thoughrnit is often desirable to consider these other factors separately.rnWhile it might seem unlikely that mine geologists can produce constrained geological modelsrnwithout the intermediary of wireframes, the technology to accomplish this is getting closer.rnIn this paper, the results of a trial at the Savage River magnetite mine, which is owned andrnoperated by Grange Resources Ltd, are reported. The trial was for a ‘direct-to-block’ implicitrngeological modelling method. The focus was on creating a geological attributed block model fromrndrill hole geological log data; resource estimates were not determined. The categories modelledrnwere air, waste, low-grade ore, medium-grade ore, and high-grade ore. The block model outputsrneither resulted in a proportional block model (categories expressed as percentages withinrnequivolumetric blocks) or a sub-blocked model (parent block and one sub-block), which is thernpreferred block model output at the Savage River mine. When compared to the traditional bestrnpractice modelling method, which takes 43 work days, the wireframe-free modelling method tookrnonly 26 hours from initial modelling, using both exploration and grade control data. An updaternusing appended drill hole data is achievable within one day. These results represent time savingsrnof more than one order of magnitude compared to the traditional workfl ow, and, as such, thesernfi gures merit serious consideration for the use of the direct-to-block modelling approach at otherrnoperations.rnWith these time savings, geological and estimation models can be kept updated constantly;rngeologists will not need to set aside two months for quarterly or half-yearly modelling of the drillrnhole data for resource review. Such dramatic time savings will allow for the better use of highlyrnskilled geologists, who are in short supply in the current market, and will also impact directly onrndownstream mining engineering workfl ows.