Thermodynamic simulation of silicon and iron reduction and zinc and lead distillation in zincoligonite ore-carbon systems

This article is devoted to theoretical investigations into the thermodynamic simulation of a zincoligonite ore (Zhairem deposite, Kazakhstan)-carbon systems in the temperature ranges from 1000 to 3000 K and pressure range from 0.001 to 0.1 MPa using the Astra bundled software based on the entropy maximum principle. It is revealed that an increase in the amount of deoxidizer in the charge results in a decrease in the degree of conversion of silicon to elemental Si because of an increase in its conversion to carbides. The lower deoxidizer content results in an increase in the silicon fraction converted to SiO at the practically complete absence of reduced elemental Si. When reducing pressure in the system from 0.1 to 0.001 MPa, temperatures for the complete conversion of zinc (1500–1200 K) and lead (1900–1500 K) and for the beginning of silicon formation (2300–1900 K) decrease. The noticeable (>50%) formation of elemental Si at P = 0.001 MPa can be attained at T ≈ 2450 K.