The use of the Eschka method for the determination of high sulphur contents

It is shown that the incineration period for determining sulphur in coal can be reduced, in a well ventilated muffle, to I hour at 775–800°, for a 1‐g. sample with 4 g. of Eschka mixture. The same time can be used for high sulphur contents with 0° i‐g. samples. The essential feature in obtaining complete precipitation of the sulphate ion is to ensure adequate excess of barium chloride of which 10 ml. of 10% BaCl2,2H2O is adequate for sulphur up to 0·08 g., a similar excess being obtained by using 10 ml. with 0·1‐g. samples for sulphur contents of 8–80%. For sulphur contents higher than 80%, 0·1–g. samples, with 70% excess of barium chloride, should be used. It is shown that the barium sulphate precipitate is most quickly and accurately determined by igniting the wet filter‐paper in a well ventilated muffle, with precautions to avoid shock‐heating.