INVESTIGATION OF THE POSSIBILITY OF REDUCING THE CIRCULATION OF VOLATILE COMPOUNDS IN A ROTARY KILN OF A DRY PRODUCTION METHOD

Abstract

The article considers a method of reducing the circulation of volatile compounds – sulfur, potassium, sodium compounds that can accumulate in the clinker burning system, circulate and lead to the formation of growths and deposits in the calciner, preheater and the loading part of the rotary kiln. The number of circulating compounds in the rotary kiln can be reduced by decreasing their degree of sublimation by converting them to less volatile compounds and removing these compounds from the firing system together with the clinker. In this case, it is necessary to provide a certain molar ratio between alkaline compounds and sulfur oxide, which depends on which compound will leave the burning system together with clinker. The introduction of potassium carbonate reduces the sublimation of sulfur oxide by 16 %, and sodium carbonate-by 45 %, due to the transfer of carbonates to less sublimable sulfates. The change of cement properties – setting time and strength, under the influence of compounds coming out with the clinker is shown. The start of setting of the cement paste is reduced by 41 %, the end of setting by 26 % with an increase in the ratio between alkaline compounds and sulfur oxide. The strength of cement in the initial period of hardening increases, and at the age of 28 days – decreases.