Research On Orebody 3D Modeling And Reserves Calculation Key Problems

Available reserves of solid mineral resources and mineralization elements spatial distribution are the foundation of mill run and mining design, directly affect the macro decision of enterprises. Traditional reserves calculation methods approximately calculate orebody volume by simple geometry. Its process is not intuitionistic and its precision is poor. With the development of information technology, reserves calculation based on orebody 3D model is intuitionistic and its result is more precise contrast with traditional calculation. However, it has not mature software with 3D reserves calculation function in our country. Orebody 3D modeling is lack of a unified theory. There are still many problems with reserves calculation basing on orebody 3D model. In this paper the key problems are studied in the process of using adjacent orebody contours to construct 3D orebody model and calculating reserves basing on 3D orebody model.Through research on orebody 3D modeling, this paper introduces a algorithm by two dimensional contours reconstructing three dimensional model. This algorithm is called perimeter projection. If adjacent contours morphological difference is larger and the difference in number of points on contours is more, this algorithm can get well result. The orebody model is more realistic, and its surface is smoothness.Through research on orebody reserves calculation methods, this paper adopts 3D integral and Kriging methods:(1) Basing on orebody 3D modle, this papers uses 3D integral method to calculate reserves. This method uses a number of distance equal and parallel planes to cut orebody. When the distance between adjacent sections is close to zero, the volume sum of between two adjacent planes is approximate to the volume of the orebody. This paper studies the relationship slice spacing and 3D integral method of volume calculation accuracy. The calculation process is simple, intuitive and volume is accurate.(2) Kriging is widely used in reserves calculation, this paper studies experiments variogram calucaltion and neighborhood points of interpolation selection algorithm in the process by using Kriging to calculate reserves:â‘ Through research on experiments variogram calucaltion, this paper studies its efficiency and robustness: Divide algorithm is adopted in the calculation process, under lager samples condition, its efficiency is high and its result is reliable; When samples deviate from normal distribution, this paper processes outliers and applies data transformation, then variogram is calculated by median method etc. and the robustness of calculation result is improved.â‘¡Through research on neighborhood points of interpolation selection, this paper introduces a algorithm of interpolation neighborhood points selection. Through establishing space distribution function of neighborhood points around estimating point, neighborhood points are selected in the process of Kriging calculation. This algorithm not noly considers the distance of estimating point and its neighborhood points in same quadrant but also considers correlation of neighborhood points, therefore neighborhood points selection is more reasonable.On the basis of above research works, this paper adopting VB6.0 for development tools in AutoCAD 2002 platform has developed the 3D reserves calculation system. It has the function of geological exploration data storage and management, and supports Excel documents and manual input. It has data processing function, includes check data errors, outliers processing, borehole track calculation, single project automatic interception, samples statistic analysis. It has 3D modeling of orebody function, includes image registration, geological interpretation, orebody wireframe modeling, orebody block modeling. It has reserve calculation function, includes 3D integral method, inverse distance, ordinary Kriging, logarithmic normal Kriging methods for calculating reserves. System is simple, suit for the geological work habits. Reserve calculation efficiency can be improved by using it. System has been used to construct orebody 3D model in Deng Xigou Pb-Zn mine. This paper has used 3D integral and Kriging methods to calculate reserves. The result shows that this system is simple and convenient to establish orebody 3D model, and reserves calculation result is reliable.