Deactivation of Coal Oxidation by Mixtures Based on Portland Cement

The change in surface properties of long-flame coal of limited metamorphic development on steeping with mixtures based on Portland cement is considered. The passivating liquids employed are the filtrate and suspension of cement solution used in grouting the bottom of mine workings. Treatment of coal with mineralized cement mixtures transforms surface groups that may be oxidized to groups that cannot be oxidized. The mineral layer formed on the coal surface prevents the development of oxidation. The results indicate that cement suspensions may be used to reduce the oxidation of the coal's contact surface in mine workings.