foerfarande foer fine grinding of foer filleraendamaal anvaenda materials in vaesentligen dry tillstaand during anvaendning of a mill with campaigned in malmedium and device genomfoerande foer of foerfarandet

摘要

The present invention relates to a method for finely-grinding minerals and similar material intended for use as filler material to a particle size appropriate for this purpose, with the aid of a mill which operates with agitated grinding medium and in which the material is ground in a substantially dry state. The invention is characterized by predetermining the stay time of the material being ground in the mill; maintaining the predetermined stay time partly by discharging ground material from the mill at a predetermined, essentially constant rate, and partly by adjusting the infeed of material to the mill in relation to the quantity of material discharged from the mill such that the amount of material present in the mill increases during the infeed of material thereto; and by interrupting the infeed of material to the mill over a predetermined short period of time when the material reaches a predetermined highest level in said mill. The invention also relates to an arrangement for carrying out the method. This arrangement is characterized in that it includes a first motor-driven device which functions to control the infeed of material, a mill for grinding with the aid of an agitated grinding medium, a perforated disc which functions to separate grinding medium from the ground material leaving the mill, a second motor-driven device which functions to maintain a substantially constant outfeed of ground material from the mill, and a level monitor which is mounted in the upper part of the mill and connected to the motor-driven infeed device. IMAGE