Abstract: The influence of sodium hexmetaphasphate, trisodium phosphate and sodium pyrophosphate on the dispersion of ultra-fine hematite and collophanite were studied by the sedimentation experiments. The results indicated that in the natural pH of distilled water, three phosphate on hematite dispersion is better than that on collophanite；For different dispersion targets, different phosphate content is required to achieve a good dispersion performance. To increase the alkalinity of the media can improve the effect of insufficient sodium hexametaphosphate on the dispersion of hematite and collophanite and insufficient trisodium phosphate on the dispersion of collophanite. The dispersion order of three phosphate-dispersants for hematite is as follows：trisodium phosphate and sodium pyrophosphate>sodium hexametaphosphate；the dispersion order for collophanite is as follows：sodium pyrophosphate>trisodium phosphate>sodium hexametaphosphate.

Key words: Hematite, Collophanite, Dispersion, Sodium hexametaphosphate, Trisodium phosphate, Sodium pyrophosphate