General principles of coal mechanization samplingThe purpose of coal sampling and sample preparation is to obtain a test coal sample whose test results can represent the entire batch of sampled coal.
The basic process of sampling and sample preparation is to first collect a considerable amount of coal, that is, the primary sub-samples from many points distributed throughout the batch of coal, and then directly combine or reduce the primary sub-samples into a total sample, Finally, this total sample is made into a required number and type of test coal samples through a series of sample preparation processes.
The basic requirement for sampling is that all particles of the sampled batch of coal may enter the sampling equipment, and each particle has an equal probability of being collected into the sample.
In order to ensure the accuracy of the test results of the obtained samples, the following factors should be considered when sampling:
a) coal variability;
b) the total number of samples taken from the coal;
c) the number of sub-samples of each total sample;
d) The mass of the specimen corresponding to the nominal maximum particle size.