Abstract: The talc powder was modified by using stearic acid, aluminate and titanate, though activation index and contact angle as characterization index, the good surface modification technology were stearic acid, titanate, aluminate content of 3%,2.5%,3%, reaction time of 1.5 h and reaction temperature of 65 ℃.The particle size and topography of modified talc powder and unmodified talc powder were investigated by particle size analysis and scanning electron microscopy, the particle size of the modified talc powder was decreased, and the dispersion was improved.After leaving along for 42 d, the caking rate of carbamide and compound fertilizer without talc powder was 26.79% and 12.96%, and the caking strength was 868.38 N/kg and 1974.11 N/kg.When 3% titanate modified talc power was added as anti-blocking agent, the caking rate of carbamide and compound fertilizer was 0.59% and 0.46%, and the caking strength was 30 N/kg and 40 N/kg.

Key words: talc powder;surface modification;caking rate;caking strength