Calculate the coking index using the ash content of blended coal and coke!

Refer to this post: http://bbs.hcbbs.com/thread-421591-1-1.html

Ash content of blended coal/Ash content of coke = Total coking ratio, as the ash content of the blended coal is transferred entirely into the coke.

It is known that the volatile matter content of the coal fed into the furnace is Mad=2.5%, and Vad=25.84%. The volatile matter content of the coke produced from this coal is Vdaf=1.2%, with Ad=12.68%. The coking efficiency can be calculated using the volatile matter contents of the coal and the coke: Kd·j=（100-Vd·m）×100/（100-Vd·j）+Q, where Vd·m and Vd·j represent the dry-base volatile matter contents (%) of the coal and the coke, respectively； The correction factor Q refers to the carbon increase resulting from secondary cracking after the volatiles in coal have escaped; it is related to factors such as the volatiles in the coal fed into the furnace, the structure of the coke oven, and the operating procedures of the coke oven. Typically, Q is set to 1. According to the dry basis conversion formula: Xd = 100 × Xad / (100 – Mad)%, we obtain Vd,m = 25.84 ÷ (100 – 2.5) = 25.84 ÷ 97.5 = 26.5%. Using the formula for converting from dry ash-free basis to dry basis: Vd,j = (100 – Ad,j)% × Vdaf,j, we get Vd,j = (100 – 12.68)% × 1.2% = 1.04784%. Thus, Kd·j = (100 – Vd·m) × 100 / (100 – Vd·j) + Q = (100 – 26.5) × 100 / (100 – 1.04784) + 1 = 73.8 × 100 / 98.95216 + 1 = 75.58%. In some national standards, Q is not set to 1 but is calculated using another formula. Unnamed1.JPG (13.49 KB), 2009-3-21 09:07; Unnamed.JPG (19.41 KB), 2009-3-21 09:07. In that case, Q = 47.1 – 0.58 × 100 × (100 – 26.5) / (100 – 1.04784) = 4.02. Personally, I believe that this calculation yields an overly high value for carbon content, which does not correspond to reality. According to these national standards, the total coking degree should be 75.58% + 3.02% = 78.6%.