الوصف

In the lower part of the furnace, mainly at the tuyeres, the following main processes occur:
(A) combustion of coke carbon
C + O2 = CO2
b) Burning of sulphur in the form of sulphurous iron
2FeS + 3O2 = 2FeO + 2SO2
C) Formation of iron silicate
2 FeO + SiO2 =(FeO)2 × SiO2
Gases containing CO2, SO2, excess oxygen and nitrogen pass up through the charge column. In this way, the gases exchange heat between the charge and them, as well as the interaction of CO2 with the charge carbon. At high temperatures, CO2 and SO2 are reduced by coke carbon and carbon monoxide, carbon disulfide, and carbon sulfuric oxide (COS) are formed):
CO2 + C = 2CO
2SO2 + 5C = 4CO+ CS2
SO2 + 2C = COS+ CO
In the upper horizons of the furnace pyrite decomposes by reaction:
FeS2 = Fe + S2
At a temperature of about ***0 0, the most fusible eutectic from FeS and Cu2S will melt, resulting in a porous mass.
In the pores of this mass, a molten stream of sulfides meets an ascending stream of hot gases and chemical reactions occur, the most important of which are listed below:
a) formation of copper sulfide from copper oxide
2Cu2O + 2FeS +SiO2 = (FeO)2 × SiO2 + 2Cu2S;
b) formation of silicates from iron oxides
3Fe2O3+ FeS + 3,5SiO2 = 3,5(2FeO × SiO2) + SO2;
3Fe3O4+ FeS + 5SiO2 = 5(2FeO × SiO2) + SO2;
C) decomposition of CaCO3 and formation of lime silicate
CaCO3 + SiO2= CaO × SiO2 + CO2;
d) reduction of sulfur dioxide to elemental sulfur
SO2 + C = CO2 + ½ S2