Abstract： To improve the compatibility of diatomite and rubber matrix, the diatomite powders were modified by the dry method, and the influence of factors on modification effect was researched. The results show that by adding calcium stearate with mass fraction of 5% in modifier and grinding the diatomite at a speed of 28 000 r/min for 1 min, activation degree of the modified diatomite powders reaches 90%, and turbidity reaches 853 NTU. The sample can reach the requirements of rubber fillings.

Keywords: diatomite; surface modification; calcium stearate