Surface modification of carborundum (SiC) particles with a modifying agent, with simultaneous ultrafine comminution in an air jet mill, was studied in this work. The production rate of SiC and the viscosity of the SiC-paraffin oil suspension were used to evaluate the performance of comminution and modification. The experimental results indicated that the modifying agent bonded onto the surface of the SiC to form an organic layer in the integrated process of modification and comminution. The types and content of modifying agents and the temperature of the compressed air have a great effect on the performance of ultrafine modified SiC, and there are some contradictory aspects between modification and comminution in the integrated process. According to the targets of both surface modification and ultrafine comminution, the optimum temperature of compressed air and feed rate of the modifying agent solution was 60 degrees C and 2 ml/min respectively, when the modifying agent A-151 was adopted to obtain the modified ultrafine SiC in one step. (C) 2011 Elsevier Ltd. All rights reserved.