Abstract: According to the features of dense soda ash produced through solid phase hydration process, combining with the main factors affecting product quality in production,the influences of mass ratio of soda to water and different additives on product′s white content and particle size etc.were studied.Results showed that the particle size and white content of dense soda ash were better when the mass ratio of soda to water was 1 ∶0.45,the mass concentration of MgCl₂ additive was 30～60 mg/L,or the mass concentration of CaCl₂ was 40 mg/L,or the mixed mass concentration of MgCl₂ and CaCl₂ was 50 mg/L,or the mass fraction of iron was 0.000 8% and the mass concentraion of MgCl₂ was 40 mg/L while the iron mixing with magnesium.

Key words: solid phase hydration process, dense soda ash, white content, particle size