Abstract: Based on the theory of nucleation and agglomeration growth in crystallography，as well as neutralization aluminum removal method，the theoretical basis for removing the aluminum in the production of chromium salt was provided.The influences of temperature，seed coefficient，degree of acidification，and neutralization time on the settlement properties were investigated.The results showed that：by controlling the conditions of neutralization，i.e.temperature of 70~90 ℃，seed mass of 0.3 g，stirring speed of 400 r/min，dropwise adding 1.5 mL sulfuric acid with mass fraction of 50%，and neutralization time of about 2 h，aluminum mud with moisture content of 35%~45%（mass fraction） and aluminum-free slurry with good settlement properties could both be obtained.

Key words: chromate production, neutralization, chromate aluminum removal, sedimentation-filtration