METHOD OF DETERMINING IMPURITIES IN STONE AND BROWN COAL AND PEAT Russian patent published in 2017 - IPC G01N23/22 

FIELD: chemistry.

SUBSTANCE: sample is fused with potassium hydroxide at a sample to sample ratio of 1:(10-20) with gradual heating of the sample with a smooth to 646-654°C for 1-1.5 hours and aging at 646-654°C for 5 min. Further, the cooled melt is treated with hot deionized water at a ratio of the initial sample to the water of 1:(400-500). The resulting solution with precipitate is treated with concentrated hydrochloric acid on heating at the ratio of the initial sample weighed to acid 1:(120-240) until the precipitate is completely dissolved. The solution is diluted with deionized water to the ratio of the initial sample to water 1:(300-2000) and the impurity element content is determined by the atomic emission method with inductively coupled plasma.

EFFECT: use of the method makes it possible to determine the impurity content in stone and brown coal and peat with high accuracy.

1 tbl, 1 ex