中国矿山工程

In the process of mineral reserve estimation, we often come across the processing of samples with exceptionally high grades, and presently there are two common methods for processing exceptionally high grades, namely Traditional Multiplier Method and Mathematical Statistical Method. By taking the sampling data from the general exploration report of Laoyachao IV gold ore body (Phase II) as the research object, this paper employs the horizontal section method to conduct the resource estimation, and in view of the phenomenon where the geological grades obtained by using the multiplier method are usually undesirably high, it also discusses the lower limit value of exceptionally high grade and the reasonableness of the processing result from multiplier method and mathematical statistical method,. The research shows that the multiplier method lacks the theoretical basis of statistics and is only empirical, while mathematical statistics can well take into account the values of relevant statistical characteristics and has mathematical and statistical implications. After the mathematical and statistical processing, the sample grade variation coefficient has been reduced to some extent, the arithmetic mean of the samples is close to and less than the Sichel valuation, the weighted grade is reduced by 0.35g/t, the geological grade after processing is more consistent with the actual conditions of RoM ore, mitigating the influence of the extra high grade samples.