Abstract
In order to establish the commercial use of the closed-circuit crushing system for the coal charge using the new vertical centrifugal screen, the crushing conditions and their effect on coke strength were investigated.In size control of the coal charge, the crushing of inert components to a specified fineness had been the major consideration so far.However, it has now been found that setting an upper limit for the sizing of reactive components is also an important factor in the forming of coke.On the basis of these results, the new, two-stage, closed-circuit crushing system (CPC-P: Coal Preparation Control Process) was proposed.
By applying this system to the manufacture of coke, it is possible to obtain coke with higher strength than the conventional crushing process by 2 digits on the drum index DI15: 5, and by 1 digits on the former SOVACO process.This high strength is due to the increased uniformity and bulk density of the coal charge, and the higher uniformity of coke texture.As a result, 5-10% of good-caking American coal can be replaced with low-rank or high inert coal.
