CONTROL OF CONCENTRATION OF SLURRY SUPPLIED FROM CLASSIFYING TANK

PURPOSE:To obtain a prescribed concentration of slurry in high efficiency and high accuracy and permit stable scale-removing operation by controlling at least one out of slurry level and stirring speed by feeding grinding material. CONSTITUTION:A concentration (a) of slurry supplied, slurry level (b), and stirring speed (c) are input into a controller 10, and each signal of a slurry concentration setting apparatus 11 and of a memory apparatus 12 related with the slurry concentration and slurry level for each stirring speed is input further, and a stirring-speed adjusting signal (d) and an iron-sand feeding amount adjusting signal (e) are output. The signal (a) of the actually measured value of the slurry concentration is a confirmation signal, and it is not required to be used as control signal. With such an adjusting method, slurry concentration can be adjusted easily. Thus, a prescribed concentration can be secured, and the efficiency of scale-removing operation can be improved.