PROCESS OF CALCINING LIMESTONE LIME IN A ROTARY KILN

摘要

A process of calcining limestone or hydrated lime by a thermal treatment with hot gases in an oxidizing atmosphere in a rotary kiln through which the kiln atmosphere and the charge are contercurrently conducted and which is fed with fuel through shell burners. The process of the invention is characterized in that different fuels which serve to produce hot gases and which release SO2 and SO3 in different quantities per unit of calorific value are introduced into the rotary kiln in such a manner that the fuel which releases a larger quantity of SO2 and SO3 per unit of calorific value is supplied to the upper portion of the rotary kiln and the fuel which releases a smaller quantity of SO2 and SO3 per unit of calorific value is supplied to the lower portion of the rotary kiln. The advantages of the invention reside mainly in that fuels which release SO2 and SO3 in relatively large quantities may be used to produce a quicklime which has a high reactivity and a low sulfur content in a process which involves low fuel costs and a low structural expenditure.