Computer thermodynamic modeling of the producing silicon alloys from the Kentau Combined Heat and Power Plant ash

Abstract

The article presents the results of studies on the production of silicon alloys from the Kentau Combined Heat and Power Plant ash by the computer thermodynamic modeling method using the HSC-6.0-Chemistry software package. The effect of temperature (from 500 °C to 2000 °C) and the amount of carbon (from 30% to 40% of the ash mass) on the equilibrium distribution degree of elements between the condensed and gas phases, the grade of resulting ferroalloys. In the system under consideration, the formation of FeSi25 ferrosilicon occurs in the temperature range of 1500-1530 °C, and FeSi45 ferrosilicon-at the temperature of 1610-1700 °C; FS50 ferrosilicon is formed in the temperature range of 1700-1900 °C in the presence of 30% of carbon. The formation of FeSi45A10 ferrosilicoaluminium is possible at 2000 °C and 30% of carbon, in this case the concentrations of the metals in the alloy are 46.51% of Si, 8.57% of Al; 42.27% of Fe. FeSi45A15 ferrosilicoaluminium is formed in the system at 40% of carbon and 2000 °C; the elements’ concentrations in the alloy are 45.62% of Si, 14.76% of Al, 37.29% of Fe. Processing of 1 tonne of the ash makes it possible to produce 459 kg of FeSi45A10 ferrosilicon