用倒推方法计算河台金矿级差品位

Calculating the class-difference-grade of Hetai gold mine by reverse deduction method

由于存窿出矿截止品位实质是级差品位的特例，因而在采矿成本、开采贫化率、掘进成本已知的条件下，可以求得备采矿量的级差品位及某个开采阶段矿块的级差品位，当矿块的地质品位不小于级差品位时，该矿块就有开采价值．为了确保矿山的利润水平，选择在黄金价格较高时适当扩大生产规模处理表外矿．

In view of the fact that the limiting grade of a produced ore is a special case of the so called class-difference grade of a mine, the class-difference grade of the prepared reserves, and that of an ore block at a particular exploita- tion phase, can be determined in terms of the mining cost. exploitation dilution rate and digging in cost, if the latter three factors are known. An ore block is said to deserve exploitation, if its geological grade is higher than its class- difference grade. In order to preserve the profit level of a mine, it is necessary to expand the production scale of the mine by exploiting the low - grade ores, when the gold price is rising.