Abstract: Effect of an additive on the oxidative roasting process of South Africa chromite was investigated.The effects of al?鄄 kali ratio（ratio of the actual amount to theoretical amount of sodium carbonate），additive dosage（mass fraction of additive on chromite），roasting temperature and roasting time etc.on the leaching rates of chromium and aluminum in the leaching process of the roasted mixture were studied.The results indicated that the additive could significantly promote the oxidative decompo?鄄 sition of chromite，remarkably reduce the roasting temperature，and effectively inhibit the leaching of aluminum from the roasted mixture.Under the conditions of alkali ratio of 1.1，additive dosage of 30%，roasting temperature of 950 ℃ and roasting time of 2.5 h， the leaching rates of chromium and aluminum were 98% and 24%，respectively，and the mass fraction of chromium oxide in the chromite processing residue was achieved about 1%.

Key words: chromite；oxidative roasting；chromite leaching rate；additive