Abstract
A contamination which occurs during the process of grinding coke as a result of abrasion of the grinding due to the hardness of coke in property is fairly well known, but despite this, no satisfactory and rapid method has been recommended for practical use up to now. Monthly average result of Fe2O3 in the ash of lump coke was higher by about three percent than in the ash of coal charged into coke-ovens. After the authors made several investigations, they found that iron came into the sample as a contamination from the crushing apparatus by hard motion of grinding.
The authors reached the conclusion that the use of an agate-mortar was the most ideal method, but was not suitable for daily practice as the process took long time. At the authors works, the sample obtained was crushed on "backing board". The use of magnet for the removal of such contamination was almost satisfactory but needed a troublesome procedure and wasted part of the sample.
Therefore, grinding of coke by a pounding method gave the minimum error and was found to to be the most recommendable.
