SEPARATION OF ILMENITE FROM RAW SAND OR MINERAL CONCENTRATES INCLUDING SEPARATION BY DENSITY, MAGNETIC SEPARATION AND A FLUIDISED BED ROAST

摘要

PCT No. PCT/AU91/00401 Sec. 371 Date Mar. 1, 1993 Sec. 102(e) Date Mar. 1, 1993 PCT Filed Aug. 28, 1991 PCT Pub. No. WO92/04121 PCT Pub. Date Mar. 19, 1992A process for enhancing ilmenite from deposits of mineral sands or mineral concentrates comprises a single stage fluidized bed magnetizing roast (16). A temperature of 650 DEG C.-900 DEG C. in an excess of a carbonaceous fuel (such as coal/char, CO or hydrocarbon) is used to provide an atmosphere in which the oxygen potential is controlled resulting in a consistently high magnetic susceptibility product. Roasting has been used before but the current process requires a lower intensity magnetic separation stage (18) and provides improved recovery (even of tailings produced by prior art roasting process). Annealing (17) of the roasted product improves the resultant magnetic susceptibility. Ilmenites having inclusions or selvedges of silicate minerals are further improved by employing a grinding step after magnetic separation prior to slagging or use as synthetic rutile feedstock. The roasting stage potentiates the ilmenite for leaching in the production of synthetic rutile.