On the correlation of the weight per cent ash of coals and their silicon content

Abstract

The high-temperature ash levels of some typical American bituminous coals can be rapidly estimated with a median standard error of ≈1.7 wt% ash (absolute) by means of a simple rectilinear correlation of wt% silicon with wt% ash. Approximately equivalent correlations are obtained regardless of whether silicon content is determined by instrumental fast neutron activation analysis (FNAA), X-ray fluorescence (XRF), or slurry-injection atomic absorption spectrometry (SIAAS). In contrast to some earlier reports, logarithmic correlations do not produce improved estimates. Correlations are not significantly improved by selecting coals within one rank or from one geographical area.