煤炭专用采样方案分析

Analysis on special sampling schemes of coal

对煤炭专用采样方案中采样精密度的指定、煤变异性的确定和子样数目的估算等主要问题进行了分析。分析表明:采样精密度值可根据国家标准的规定值或推荐值指定或比其更小,但不可任意指定过小的采样精密度值,以免实际采样中无法实现;不建议采用VI=20和VPT=0.2来确定煤的变异性,最好进行各被采样煤的变异性的实际测定;当批煤被划分成多个采样单元并需估算子样数目是否足够时,应进行采样精密度的核验以证明能否符合预期精密度的要求。

The main problems of special sampling schemes of coal, such as designated sampling precision, determination of coal variability and estimates of the number of sub-samples, were analysed in this paper. It was demonstrated that the precision of sampling values could be designated as the specified value or the recommended value according to the national standards or be smaller than them, but the too small sampling precision value should not be recommended arbitrarily so that it was too difficult to meet the requirement of precision in practice. Then, it was not recommended to determine the variability of coal by factors valuing at VI = 20 and Vp-r = 0.2. it was best to determine the actual variability of coal of samples one by one instead. When the batch of coal was divided into multiple sampling units and it was necessary to estimate and judge the number of subsamples if it was enough or not, the sampling precision should be verified in order to meet the expected precision requirements.