TREATMENT OF SLAG FORMED IN COAL GASIFICATION

PURPOSE:To prevent yellow water from being produced, remove malodor of hydrogen sulfide gas and contemplate the effective utilization of slag formed in coal gasification, by mixing a sulfite salt with the formed slag. CONSTITUTION:A sulfite salt is mixed with slag formed in the gasification of coal comprising blowing coal together with a gasifying agent into a molten iron bath and gasifying coal. For this purpose, slag discharged from a coal gasifying furnace is crushed to an appropriate size according to the purpose of use, and then a required amount of the sulfite is added, to convert CaS in the slag into CaS2O3. As said sulfite, calcium sulfite is most preferred. Calcium sulfite is available in large quantities at low cost as a by-product in an exhaust gas-desulfurizing provision for air pollusion prevention. Calcium sulfite is added in an amount which corresponds to a particle size of the slag and contents of CaS and which does not reduce the strength of the slag itself.