Extraction method for the determination of total chlorine in coal

Abstract

A solution of 0.1 M KNO₃ in dimethyl sulphoxide was demonstrated to leach chlorine quantitatively from a variety of coal samples. Analysis of the leachates by ion chromatography confirmed that the chlorine in the coal was entirely in the ionic form. When the extraction was performed in a ball mill, water was found to be a suitable leaching medium; however, the time required for the quantitative extraction of chorine was increased. The combination of this extraction with a subsequent titrimetric determination of chloride provides a convenient alternative to methods that require special equipment such as an oxygen bomb combustion system, particularly when a large number of samples are to be determined.