In order to study the basic reactions in the coal gasification by molten iron, the influence of sulphur or phosphorus on the rate of dissolution of graphite from rotating graphite cylinders into liquid iron alloys was investigated. The experiments were conducted in a temperature range of 1573–1773 K with rotational speed varying from 1.67 s⁻¹ to 65 s⁻¹. Two kinds of electrode-grade graphite (non-graphitic and graphitic carbon) were used. The results are summarized as follows:
(1) Phosphorus decreased the overall mass transfer coefficient k, the reduction of which was presumed to be due to the effect of phosphorus adsorption on the graphite/iron interface.
(2) Sulphur decreased k more than phosphorus, suggesting a more intensive surface activeness of sulphur. Particularly in the case of non-graphitic carbon, k extremely diminished.