Abstract:Effects of several coupling agents on oil absorption value and active index of organizing modification red mud powder were comparatively studied to obtain the optimum coupling agent and its usage conditions. The experimental results show that FH-1(NDZ-101 DL-411-D) compound coupling agent has the best modified effect on red mud. The optimum modification conditions include dosage of FH-1 of 1.0%~1.2% of red mud mass, modification temperature of 120~150 ℃, and modification time of 0.5~1 h. The modified red mud with oil absorption of 30 mL below per 100 g powder and activation index of 95%~97% can be used as inorganic mineral filler to prepare organic composite materials.