Education of the republic of uzbekistan tashkent state technical university named after islam karimov

2Zn
О∙SiO
2
+ 2CO + O
2
= 2ZnO + SiO
2 
+
+ 2CO
2
 
Figure 6. Diagram of the change in the 
value of the free energy of the reaction 
2Zn
О∙
SiO
2
 + CaO = CaSiO
3
+ 2ZnO 
2ZnО∙SiO
2
+ CaO =CaО∙SiO
2
+ 2ZnO
(7) 
ZnО∙Fe
2
O
3
+ CaO =CaО∙Fe
2
O
3
+ ZnO
(8) 
CaO + SiO
2
=CaО∙SiO
2
(9) 
CaO + Fe
2
O
3
=CaО∙Fe
2
O
3
(10) 
The thermodynamic substantiation of the possibility of the above reactions (7), (8), (9), 
and (10) at the temperatures of oxidative firing in the RL furnace are determined by the change 
in the value of the free energy of the reactions. The results of thermodynamic calculations are 
shown in Figures 6, 7, 8, 9, respectively. 
The thermodynamic substantiation of the reactions of the interaction of the charge 
components according to the proposed mechanism has been carried out. The optimal firing 
temperature and the amount of additional component CaCO
3
added to the firing charge were 
selected. 
Both (9, 10) these reactions actively proceed in the temperature range of 400-700 °C, 
while the formation of ferrites in zinc silicates occurs at 950-1050 °C. 

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Geological Engineering
134 
Figure 7. Diagram of the change in the 
value of the free energy of the reaction 
Zn
О∙Fe
2
O
3
 + CaO =Ca
О∙
Fe
2