Studies of the sintering method of ash and slag waste for the production of alumina from self-disintegrating sinters

The goal of this research is to select the optimal composition of the sintering charge of ash and slag waste for maximum extraction of alumina and obtaining self-disintegrating sinters of a given chemical composition. Experiments have shown that sintering of ash and slag waste using two-component charges makes it possible to extract alumina from sinters by no more than 60 %. The highest sintering rates were made using three-component charges. So, when sintering ash and slag waste from Almaty TPP-2 on a three-component charge of the composition CaO:SiO₂ = 2; Na₂O:(Al₂O₃+Fe₂O₃) = 1 at a duration of 60 min and a temperature of 1200 °C, alumina extraction was 83.68 %, under the same conditions, alumina extraction of 87.07 % was obtained during sintering of ash and slag waste from the Eurasian Energy Corporation, and alumina extraction was 90.2 % during sintering of ash and slag waste obtained after preliminary chemical activation. As a result of the conducted research on sintering of ash and slag waste in a three-component charge system, a self-disintegrating sinter of the following chemical composition was obtained, %: Na₂O - 0.07; CaO - 26.88; SiO₂ - 2.06; Fe₂O₃ - 5.01; Al₂O₃- 5.059.