Abstract: Thermal decomposition of NaNH4CrO4•2H2O was studied by means of thermogravimetric analysis (TG),differential thermogravimetric (DTG), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results showed that the thermal decomposition of NaNH4CrO4•2H2O proceeds in three steps, i.e., the release of crystal water at temperature from 50 ℃ to 95 ℃ at first, the formation of the intermediates sodium chromate and ammonium dichromate with the partial release of ammonia at temperature from 100 ℃ to 180 ℃,and the complete elimination of ammonia from 215 ℃ to 385 ℃ .In flowing ambient and suitable temperature（400～790 ℃）,the final decomposition product was mostly sodium dichromate. This leads to a cleaner process for sodium dichromate production.

Key words: NaNH₄CrO₄•, 2H₂O, Thermal decomposition, Cleaner process