Sodium gold sulfite is a major gold salt used in cyanide-free gold electroplating,but there is no report on the removal and control of chlorine ions in sodium gold sulfite.Sodium gold sulfite solution was prepared in tests,and the adsorption behavior and removal of chlorine ions in gold hydroxide were studied.The gold hydroxide was fully washed with deionized water until no white precipitate was observed when silver nitrate was added to the filtrate.The mass concentration of chlorine ions in the 50 g/L (calculated according to Au) sodium gold sulfite solution prepared was about 220 mg/L.Through the adsorption isotherm curve fitting,the adsorption of chlorine ions by gold hydroxide was fitter into the Langmuir adsorption model.The Gibbs free energy of the adsorption reaction was -18.4 kJ/mol,indicating that the adsorption of chlorine ions was mainly physical adsorption.The chlorine ions in sodium gold sulfite could be further removed by ethanol antisolvent precipitation.The removal rate of chlorine ions by single antisolvent precipitation was about 43 %.After 3 times of antisolvent precipitation,the mass concentration of chlorine ions in the 50 g/L (calculated according to Au) sodium gold sulfite solution was reduced to 40 mg/L.The results of this paper could provide certain theoretical and technical guidance for improving the quality of sodium gold sulfite product,a cyanide-free gold salt.