Preparing high purity white carbon black from rice husk.

In this paper, rice husk (RH) was used as raw material to prepare white carbon black, and the key technological parameters of preparing white carbon black from RH were studied through single-factor test, orthogonal experiment, and response surface analysis. Meanwhile, the characteristic of white carbon black was also analyzed. Through orthogonal experiment analysis, it was confirmed that the order of factors affecting the purity of white carbon black was calcination temperature > alkali treatment time > final pH > surfactant. Based on the response surface optimization analysis, the optimum parameters for preparation of white carbon black were as follows: calcination temperature 610°C, alkali treatment time of 2.3 hr, final pH of 10, CTMAB was used as the surfactant. Under this condition, the purity of silica prepared could be reached to 99.39%, and the particle size was uniform, spherical, and well dispersed, which satisfied the requirements of GB/T 34698-2017 standard.