the student s of the group ЕМ – 10 1/9 Yuhno A . Muravyov E.

1. Rational Technology of Fe-Si 45 Production Process the studentsof the groupЕМ – 10 1/9 Yuhno A.Muravyov E.

2. The alloy characteristics and use • Ferrosilicon is alloy of silicon and iron. It is mainly used as a dioxidant and alloying element in producing steel. Fe-Si 45 requirements

4. The charge materials characteristics. Metallurgical quartzite. Fraction requirements Metallurgical quartzite requirements

5. Physico-chemical basis of the process SiO2 + SiFe = 2SiO; SiO + C= Si+ CO. As an intermediate product formed at 1700 оC carbide silicon is SiO + 2C= SiС+ CO. At the appropriate temperature silicon carbide destroys iron: SiС+ Fe = FeSi+ C For that part of the silicon which forms iron silicide the reaction is : SiO2 + 2C = Si + 2CO2 Si+ Fe= FeSi _____________________________________________ SiO2 + 2C + Fe = FeSi+ 2CO2 Figure 1.1 - Diagram of the Fe-Si

6. Physico-chemical process • Theoretical temperature of the recovery silica with carbon by reaction: SiO2 + 2C = Si + 2CO is(ΔGo = 0 at T = 1962 K),and eutectic temperature in the systemFeO - SiO2 T = 1451K. • The reaction of silicon recovery from silica using solid carbon is performed by the total reaction : SiO2 + 2CО= 2CO2 + Si; ∆H = 306,18 kJ/mol 2CO2+ 2C= 4CO; ∆H = 345,392 kJ/mol SiO2 + 2C = Si + 2CO; ∆H = 651,572 kJ/mol • During the silica process the pressure on the throat is equal to atmospheric and in the area of silicon recovery it is a bit higher than atmospheric. Due to the iron which dissolves silicon in the reaction zone the balance shifts to the right and recovery of the silica starts at 1150 оC.

7. The mechanism of recovery in three-phase furnaces. • the formation of silicon carbide by the interaction of silica dioxide with quartzite and solid carbon from coke; • retention by coke carbon gaseous silicon monoxide , which is formed in the lower high-temperature horizon of the throat and rises to the upper horizon. As a result of this reaction silicon carbide is produced; • the exothermic reaction of disproportionation. This is the process of disintegration of gaseous silicon monoxide, carbon coke which has not been detained on silicon and fine (powdered) silica.

8. Selection and justification of technology

9. The features of carbon as a reductant: 1)carbon monoxide in astate of gas all the time allocated from the furnace, so achieved a high degree of extraction of the lead element from the ore (up to of 95-98%);

10. 2) Affinity of carbon relative to oxygen increases with increasing temperature, which makes it possible to restore various oxides; 3) Carbon is a cheap reductant. As carbon reductant elements can be used: coke, nut coke, anthracite, wood sawdust, peat coke and pitch;

11. Parameters of the normal run of the furnace

12. The technological process is characterized by: • Even gas evolution on the entire surface of the throat. • Absence of dark sintered areas and local excessive gassing – “fistulas”. • Even chargefall near the electrodes and in the triangle between them. • Stable submergence of electrodes deep in the charge. • Stable downloading of charge. • Regularly output of rare movable slag in each output of the melt.