Abstract: Oxygen volume fraction distribution in rotary kiln was studied by numerical simulation（CFD） technology for the importance of oxygen on temperature distribution and increasing chromite oxidation rate during roasting process.The general law of oxygen volume fraction distribution in the air roasting process was analyzed，then the effect of excess-air coefficient，different oxygen volume fractions of inlet wind on temperature distribution and oxygen volume fraction in rotary kiln was discussed.Result indicated that，when excess-air coefficient was 1.7，oxygen volume fraction near wall continually reduced lengthwise along kiln；in this condition oxygen volume fraction of kiln tail gas was about 7.5% and oxygen in rotary kiln tended to distribute evenly after high temperature oxidation area；the proper excess-air coefficient was  about 1.7；with increasing oxygen volume fraction of inlet wind，kiln temperature would obviously rise in the beginning，then decreased slightly.

Key words: chromite, rotary kiln, numerical simulation