基于多维概率分布的多金属矿床储量估算模型

Reserve evaluation model of polymetallic deposits based on multidimensional probability distributions

为解决不同边界品位下多金属矿床的储量快速估算问题,针对多金属矿床有用组分之间具有相关性的特点,基于多维概率分布函数建立了多金属矿床储量估算数学模型.以某金铜矿床为例,分析证明了矿床中金、铜品位的概率密度呈对数正态分布,并对金、铜品位分布的相关性特征进行检验.在此基础上将一维概率密度扩展至多维,建立了金铜矿床品位分布的多维概率密度函数,得出了不同边界品位下矿床保有的资源储量,并进行了可靠性验证.结果表明,模型的计算误差在10%以内,符合储量管理的精度要求.

A mathematical model was built up to realize a quick reserve evaluation of polymetallic deposits based on a multidimensional probability distribution function in view of that there exists a certain correlation between valuable components in the polymetallie deposits. The model was verified by studying a gold-copper deposit ease. In the case, it was proved that the probability density of both Au and Cu grades obeys a logarithmic normal distribution, based on which the correlation between them was verified. Then a function of the muhidimensional probability distribution of grades in the gold-copper deposit was established after the probability density distribution was expanded from one-dimension to muhi-dimension. The corresponding reserves for different cut-off grades were calculated with the help of the function. The model was proved reliable for the calculation error was less than 10% , which is an accepted accuracy for reserve evaluations.