GB/T 22279-2008Guide for development of certified reference materials for the composition analysis and the physical property measurements of coal (English PDF)

3.1 Candidate choice of coal samples

3.1.1

Candidate samples should be suitable for the intended use, easy to obtain and copy, and its basic characteristics (content, coal or matrix composition, etc.) and application areas

The daily test object is similar, and the characteristics of the undetermined characteristics have longer-term stability. Copy candidate coal samples of the species and the main characteristics of the amount should be with the original

The standard material as close as possible.

3.1.2

series of coal composition analysis and physical characteristics of the standard sample candidate coal sample to be determined quantitative values should be reasonable to meet the requirements

The content of the gradient, as much as possible to cover a larger measurement range.

3.1.3

Generally, a candidate coal sample shall be taken from the same coal type or the same batch of commodity coal at the same mine site; if necessary,

However, both coal and matrix are similar to the two kinds of coal preparation.

3.1.4

Candidate coal samples should be sufficient in quantity to meet the usage during the life and market needs.

3.1.5

candidate coal samples before preparation or before the preparation of the required particle size, should be extracted 1-2 samples for pre-detection of the value of the characteristics to be determined, if the determination

Similar to the expected target value, the sample preparation step can be followed; if the measured value and the expected target value vary widely, measures should be taken (re-mining

Select candidate coal samples, or coal samples with the same matrix) to make the candidate coal sample to be determined the magnitude of the expected value is close to the expected value.

3.2 Sample Preparation

3.2.1

Sample preparation and packaging should be in line with the requirements of GB 474, and the ambient temperature does not exceed 30 °C, the relative humidity of not more than 75% of the sample

Indoor.

3.2.2

According to the nature and quantity of selected coal samples, as well as the nature of the value to be quantified, choose a reasonable broken, drying, screening, mixing and shrinking division sequence. The coal samples with too high water content should be prepared after proper drying. The samples with the required particle size range should be prepared by stepwise crushing method.

3.2.3

Sample size should be consistent with the method of quantitative measurement requirements.

3.2.4

prepared to the appropriate size of the coal sample, should take effective blending methods, such as rotating in a ball mill for a certain period of time or repeated pile reactor doped

Times and make it fully mixed, and placed at room temperature for a sufficient time to reach the air dry state and then sub-packaging to the smallest unit. To be

Determined by the characteristics of coal samples oxidative deterioration significantly affected the sample should be as much as possible in the same day, up to no more than two days to complete the packing.