Selective flotation of ilmenite from ilmenite-rutile mixtures

摘要

The surface properties of rutile and ilmenite in aqueous solutions of a cationic collector, hydrogenated tallow amine acetate (HTAA), was investigated by making use of the zeta potential, contact angle, infra-red spectroscopy, and micro-flotation techniques. The zeta potential measurements yielded the isoelectric point (iep) of rutile as pH 3.5 and that of ilmenite as pH 4.4 in the presnece of 10~(-2)M KNO_3. The iep's of rutile and ilmenite in the presence of 10~(-4) M HTAA were found tob e pH 11.2 and pH 11.5, respectively. Micro-flotation tests indicated that the recovery of rutile diminished to zero above pH 11.5 in the presence of 6x10~(-6)M HTAA, while ilmenite kept floating at this pH. A selective separation of ilmenite from ilmenite-rutile mixtures was carried out using 7.5x10~(-6)M HTAA at pH 12. The flotation recovery of ilmenite reached 84 percent while that of rutile remained only at 16 percent.