基于空间变异性的IDW矿石品位估值改进方法

Improved IDW method for ore grade estimation based on spatial variation

为满足距离反比加权(IDW)插值方法在矿石品位估值中的应用,对IDW方法进行了改进.通过地质统计学中的变异函数理论分析钻孔样品数据中元素品位的空间变异性,根据矿体形态计算矿体走向、倾向和厚度3个相互垂直方向的定向变异函数,进而使用3个方向和相应变异函数的变程值确定搜索椭球体的参数.采用八分圆空间分区搜索方法对每个八分扇区内参与插值的样品个数加以限制,从而减少样品数据聚类效应;根据钻孔勘探网度,将空间搜索范围以及钻孔工程数与储量等级进行对应,实现矿石资源级别分类.通过C++语言在HOOPS三维可视化平台编程实现了该方法和计算结果的可视化,以某铜矿实例说明该方法的具体步骤.结果表明该方法简单有效,能够得到很好的估值结果.

Aiming at the inverse distance weighting（IDW） method for ore grade estimation,we improved the original IDW method.Spatial variation of grade values belong to the sample data was analyzed with geostatistic variogram theory.According to the shape of ore body,three dimensional variogram models in the direction of strike,dip and thickness were calculated.And then these three directions and range values of variogram models were used to define the parameters of search ellipsoid.An octant searching scheme with constraint of sample count in per octant was carried out for reducing clustering effects of the sample data.On the basis of the density of exploration grid,the search area and number of drill hole were considered to classify the resource and ore reserve.This method was implemented by using C＋＋language on the Hoops platform for three dimensional visualization.The workflow of the ore grade estimation using this improved IDW method was summarized by the example of a copper mine.The results show that this improved method is simple and effective.Moreover,it can produce good ore grade estimation.