Rapid acid extraction of bituminous coal for the determination of phosphorus

Abstract

A rapid acid extraction method for the determination of phosphorus in coal is described. Coal is weighed into polypropylene bottles, hydrofluoric and hydrochloric acids are added and the resulting mixture is heated in a microwave oven. Boric acid is then added to complex the fluoride. Phosphorus is determined by spectrophotometry, as the molybdovanadate complex, in an aliquot of the acid extract. This method is a rapid alternative to the commonly used methods, which require the prior oxidation of coal. A comparison of results for the analysis of 22 coals by this method and a standard method indicate that the proposed method is accurate.