General analysis test coal sample preparation procedureGeneral analysis and test coal samples should meet the requirements of national standards related to the determination of general physical and chemical characteristics.
General analysis and test Coal sample preparation is usually carried out in 2 to 3 stages. Each stage consists of drying (when needed), crushing, mixing (when needed) and shrinkage. If necessary, the reduction stage can be increased or decreased according to specific conditions. The particle size of the coal sample and the quality of the reduced coal sample at each stage shall meet the requirements of Table 1.
In order to reduce the error of sample preparation, the reduction stage should be minimized when conditions permit.
The prepared coal samples for general analysis and testing should be filled into coal sample bottles, and the amount of coal samples should not exceed 3/4 of the volume of the coal sample bottles, so that they can be mixed during use.