Rapid Coal Analysis. Part II: Slurry Atomization DCP Emission Analysis of NBS Coal

A McCrone Micronising Mill is used to wet grind NBS bituminous coal to a median particle diameter of 5.7 μm within 10 min. The finely divided coal slurry is immediately nebulized without sieving into a three-electrode DCP for accurate trace element determinations within 15 min overall elapsed time. Three important parameters contribute to near-quantitative elemental recovery without the use of wet or dry ashing, matrix matching, standard additions, or correction factors. These parameters are: (1) extremely small coal particle size, (2) spray chamber conditions favoring unusually efficient aerosal mass transport, and (3) high particle atomization efficiencies characteristic of the hot DCP. Near-unity response factors are observed for the rapid DCP emission determination of trace metals in finely divided coal slurry. Calibration may therefore be performed simply with aqueous standards. The slurry method gives near quantitative agreement between experimental and certified values for Cr, Cu, Mg, Mn, Ni, and Pb in NBS bituminous coal.