Orebody Models Research Articles

A Critical Survey of the Existing Stope Layout Optimization Techniques

The analysis of algorithms to optimize the geometry of the stope limits in underground mines is performed on the block orebody models, and its results are reported. The scopes of application of the existing methods and algorithms are given.

Detailed Orebody Mapping using Borehole Radar

Detailed orebody delineation on a mine scale is usually carried out predominantly by the interpretation of information from drillhole core and cuttings. Inaccurate interpolations between drillholes can result in dilution and ore loss. This paper presents examples of the use of borehole radar to provide more continuous maps of nickel sulphide orebody outlines in Western Australia. These examples show that these maps can substantially reduce the uncertainty of orebody models resulting in improved mine plans, reduced dilution and improved ore recovery.The data presented were collected with the GeoMole borehole radar system. This system is not directional. However, by combining information from other sources, the 3D locations of the reflectors that are imaged can often be accurately estimated and the potential errors quantified. Difficulties have been encountered when the system has been operated in salt water filled holes but good results have been obtained in these holes after they have been flushed with fresh water. The system has also been used in updipping holes up to 120 m long.The results obtained to date indicate that substantial cost benefits can be obtained at some mine sites by incorporating borehole radar surveys into the ore delineation process.

Conditional simulation algorithms for modelling orebody uncertainty in open pit optimisation

Conditional simulation is a class of Monte Carlo techniques that can be used to generate equally probable representations of in-situ orebody variability. Contrary to the traditional smooth orebody models, conditionally simulated orebodies provide the tools to quantify uncertainty in grade variability and the resulting effects on various aspects of open pit design and planning. This paper outlines a general framework for modelling uncertainty and assessing geological risk, presents currently used geostatistical simulation algorithms, and presents examples.

Quantifying differences between computer models of orebody shapes

Abstract Several different methods have been used for the representation of orebody shapes in computer systems including serial-slice, gridded seam, regular block, mathematical functions, solid geometry, and boundary representation models. The accuracy and precison of such models are affected by factors such as errors associated with the original data used, natural variations, errors in data capture and processing, etc. In order to asses the relative importance of such factors it is necessary to quantify differences in accuracy and precision between different model structures. To meet this objective a new technique which relies on statistical study of a series of sample lines, intersecting two or more different orebody models, is proposed. Application of this technique on orebody models at the Neves-Corvo copper-tin deposits in southern Portugal suggested that in certain circumstances regular block models can give very poor estimates of the total volume of materials of different geological types. In addition it was shown quantitatively that shape interpretations close to the plane of drill-sections are better, in terms of accuracy and precision, than interpretations for zones falling between the drill-section planes.

The application of DATAMINE in kaolin resource management

Abstract The computerized reserve evaluation system developed in house for ECCI’s UK kaolin operations served well from 1981 to 1987 but, with an evolving data base and increasingly more sophisticated demands placed upon it, its limitations became ever more apparent. It was clear that to maintain the system and develop it at the required pace was not feasible. Therefore the decision to replace it with a proprietary system was taken and DATAMINE was installed in July 1988. The new system has been installed to operate in parallel with the ECLIPSE ground modelling system which has been in operation at ECCI since early 1985 and has made significant impact in the fields of surveying, mapping and of quarry and tip design. At the present time, 900f the Mid Cornwall China Clay region has been mapped using this system and topographic update is readily available in digital format for quick assimilation into DATAMINE, speeding up model construction immeasurably. The application of DATAMINE is discussed in terms of its role as a tool in resource management and the construction of orebody models for primary kaolin deposits is briefly described. In order that the system could be made more specific to ECCI’s kaolin operations, a series of macros have been developed which essentially customize DATAMINE to ECCI’s specific requirement whilst maintaining total flexibility. These macros are described in broad outline and this serves to illustrate how the system is being applied in this particular situation. The ultimate goal is to provide a comprehensive and flexible overview of ECCI’s kaolin resources in SW England. This overview, coupled with a mineral extraction and debris disposal schedule, is a key component in the cost effective management of ECCI’s mineral business.