The following issues should be clarified before calculation:
Different grades of ferrosilicon due to different smelting temperatures, so the calculation of the excess of carbon and silicon recovery is also different. Ferrosilicon smelting temperature is lower, carbon and silicon ground ferrosilicon smelting temperature is higher, the loss of carbon and silicon is greater, so the excess of carbon is calculated at 10%, the recovery rate of silicon is calculated at 92%.
2. Atomic weight, molecular weight calculation
According to the periodic table of chemical elements can be known as the atomic weight of silicon 28, the atomic weight of carbon is 12, the atomic weight of oxygen is 16, so the molecular weight of SiO2 is 28 + 16 × 2 = 60.
100 kilograms of silica contains SiO2: 100 × 98% = 98 kilograms.
Ferrosilicon smelting reaction formula: SiO2 + 2C = Si + 2CO
SiO2 and 2C molecular weight: 28 + 2 × 16 = 60 2 × 12 = 24
90 kilograms of SiO2 pure carbon amount is: 24/60 × 98 = 39.2 kilograms
We use coke containing 84% carbon, 39.2 kilograms of pure carbon converted to coke, it is: 100 / 84 × 39.2 = 46.6 kilograms
Smelting 75 ferrosilicon, the coke burnout is about 10%, so the coke intake is:
46.6 × 100/90 = 51.7 kg ≡ 52 kg
The water content in the coke is about 5% to 15%. Experience proves that for every 1% increase in coke content, 0.6 kg of coke should be added accordingly. If the coke content is calculated as 5%, the actual amount of coke added will be: 52+52×5%×0.6≈54kg
Simplifying the above and the calculation formula, the amount of coke added for smelting 75 ferrosilicon for 100 kilograms of stone would be:
100×SiO2×24/60×C%×0.90=Coke addition (kg)
Where SiO2-carbon dioxide content of silicon in the %
C%-% fixed carbon content in coke
0.9-Carbon utilization rate (10% due to carbon burnout).
24 and 60- molecular weights of 2 carbon and carbon dioxide silicon, respectively.
The amount of coke added, calculated using the simplified formula, is not the actual amount needed, but is increased according to the coke content.
(2) Calculation of the amount of coke added to the coke for smelting 45 ferrosilicon
This is the same as the smelting of 75 ferrosilicon coke addition calculation, no big difference, only because of the low temperature of the furnace, coke burn loss is less, according to the calculation of 7%. Applying the simplified formula above, the coke addition is calculated as:
Coke addition = 100×SiO2%×24/60×C%×0.93
Where 0.93 is the utilization rate of coke (because 45 ferrosilicon coke casting loss of 7%) Substituting the composition of raw materials into the above formula.
Coke added = 100 x 0.98 x 24/60 x 0.84 x 0.93 = 50 kilograms
For example: the water content in the coke is calculated at 5%, the actual amount of coke added is.
50+50×5%×0.6=52 kilograms
