Abstract: In order to delineate the ore-body in the three-dimensional visualization environment to establish the three-dimensional model of ore-body,the method of automatic delineation method of the single engineering ore-body is analyzed.According to the data of drillhole,samples analysis,survey and geological lithology,the three-dimensional drillhole model is establihsed by caculating the drillhole spatial trajectory and drillhole attribute data.Based on the three-dimensional drillhole model,according to the industrial indexes of deposit (including cutoff grade,minimum mining thickness,rock eliminating thickness,minimum industrial grade,minimum meter percent,et al),the drillhole samples of three-dimensional space are composited,the grade of composite sampels grade are calculated by the length of the drillhole samples or the weighted average values of the product of samples length and specfic gravity.The vector of thickness direction is calculated by the dip direction and dip angle of ore-body,the vectors of each ore-bodies are calculated based on the spatial trajectory of the three-dimensional drillhole model.The true thickness of ore-body is proposed by the vector that is obtained by projecting the vector of each ore-bodies to the thickness direction.The ore-body delineation methods based on the single index of cuttoff grade and the two indexes of cuttoff grade and minimum industrial grade are implemented.The ore-body delineation methods proposed in this papaer is tested by the drillhole data of a copper mine in Yunnan province,the results show that the ore-bodies can be delineated effectively based on the given industrial indexes by adopting the single engineering ore-body delineation method,therefore,the ore-body delineation method proposed in this paper is good for improving the precise and working efficiency of ore-body delineation.

Key words: Three-dimensional model of drillhole, Ore-body delineation, Grade composition, True thickness, Industrial index of ore-body