SAETT ATT FRAMSTAELLA EN SUSPENSION AV FAST MATERIAL I HOEG KONCENTRATION, SAERSKILT EN SUSPENSION AV KOL I VATTEN

After preliminary-grinding to a maximum size of 6 mm the coal is micronized by wet milling in a first mill containing water and suspension-stabilizing additives, the weight ratio between the solid and water being comprised within the range of from 35/65 to 60/40 preferably 51/49; the additive content being within the range of from 0.3% to 3% by weight relative of the solid. The aqueous suspension containing the solid is micronized to a maximum size of about 20 mu m and is used as a diluent medium in a second mill; into which is fed a charge constituted by ground solid and by the above mentioned aqueous suspension, the weight ratio between the above mentioned aqueous suspension and the ground solid being within the range of 46/54 to 75/25 preferably 51/49. The milling in the second mill allows a suspension to be obtained, wherein the average size of the micronized solid is substantially unchanged and the product obtained does not require further mixing or water separation stages in order to obtain the suspension at the desired concentration.