Study on the fluidized bed granulation of fine-grained rutile concentrate

Abstract

The particle size of rutile concentrate in China is too fine to meet the requirement of chlorination process. It needs to be granulated into micelle with the diameter about 100μm before chlorination. The fluidized bed granulation method was used to prepare micelle, and the influence factors on granulation were studied. The results show that the relative high concentration and the increase of spray time are favorable to particle growth. To obtain good granulation performance, the proper concentration of binder solution, filling ratio and spray time were 0.8%, 1.8% and 60min respectively while using carboxymethyl cellulose sodium (CMC) as the binder. The mean diameter of the final product is approximately 103μm with uniform particle size distribution, and the particle sphericity is improved. The granulating mechanism of micelle shows that agglomeration and layering growth coexist during the granulation process. The particle growth is controlled by agglomeration growth at the early stages of granulation, and coating is the main growth manner at the end of granulation.