METHOD OF PROCESSING LEATHER WASTES INTO LEATHER POWDER Russian patent published in 2000 - IPC

FIELD: leather industry; applicable in utilization of leather wastes. SUBSTANCE: wastes of natural leather are preliminarily ground to obtain particles sizing 0.5-5 mm. Added to ground leather is hydrolyzing agent in the form of lime or its mixture with salts of alkali metals with total content of hydrolyzing agent of 2-6% of dry collagen and content of lime in hydrolyzing mixture of not less than 50%. Then wastes are moistened to content of 80-100 wt.p of water for 100 wt.p. of collagen. Prior to grinding, moistened wastes are rolled at temperature of 15-35 C for 5-15 min and drying of wastes at temperature of 110-150 C. Further on embrittled wastes are ground on ball or vibratory mills of any design to obtain particles sizing 3-30 mcm. EFFECT: higher quality of grinding of natural leather wastes; increased product yield and quality; excluded formation of sewage waters from waste processing; reduced power consumption for waste drying. 1 tbl, 12 ex