Modification of poorly clinkering DG coal

In a recent issue of this journal, Malyi described experiments on the modification of DG coal for its subsequent use in coking batch in place of G coal. Analysis of that paper shows that, contrary to Malyi’s statements, there is no shortage of G coal, because the Donets Basin comfortably meets the demand. The model mixture that Malyi uses for modification is complex in composition and contains considerable sulfur. He does not state its properties or the available reserves. Malyi’s ideas regarding the pyrolysis of coal are shown to be very contradictory, while his experimental data prompt skepticism, since the measured ash content, total sulfur content, and clinkering properties of the batch differ from those calculated on the basis of the properties and proportions of the batch components. When using batch that contains modified DG coal in place of G coal, the coke yield is reduced, and its quality is impaired. These findings support the conclusion that Malyi’s research is unnecessary, unpromising, and unworthy of further consideration.