PURPOSE: To obtain coke having a high strength and suitable for use in blast furnaces, by a method wherein the particle size of feedstocks such as coal is controlled so as to make an index, expressed by a specified expression, a numerically small value, and the feedstock is introduced into a coke oven.
CONSTITUTION: Each feedstock such as coal is ground and the particle size of the ground feedstock is controlled so as to make an index D expressed by the expression (wherein N is the total number of feedstocks; Fi is the weight ratio of the i-th blending species ; X is the softening melting characteristic value of the whole feedstock; Xi is the softening melting characteristic value of the i-th blending species; Piα is the weight % of the residue through αmm mesh size in the i-th blending species) a numerically small value. Then the feedstock is introduced into a coke oven. As the αmm mesh size, 3mm is usually preferred. The figure shows that the smaller the index D is made, the higher is the strength of coke obtd.
EFFECT: Grinding energy can be saved.
MIYAGAWA TSUGIO
TANIHARA HIDETAROU
