Abstract:The effect of sulfur on evaporation salt discharge from sodium aluminate solution bearing Na2C2O4 was studied by adding different amount of Na2SO4 and Na2S respectively. The results show that when concentration of sodium oxalate is NS=6 g/L, sodium sulfate exerts effect on crystallization of Na2CO3, sulfur salt, Na2C2O4 and NaAlO2 in sodium aluminate solution. Salting-out rate and brine rate rises with increase of adding amount. With Ns=6 g/L, brine rate is 92.02%, and there are Na2CO3, Na2C2O4, NaAlO2?1.25H2O, Na2SO4, Na6CO3(SO4)2, and Na4(SO4)1.39(CO3)0.61 in evaporation residue. Adding sodium sulfide can also improve salting-out rate and brine rate with limited effect. With Ns=6 g/L, brine rate is as only as 71.71%, and crystal phase are Na2CO3, Na2C2O4, NaAlO2?1.25H2O, Na2S, Na2S2O3, and Na2SO3, etc, with no double salt crystallization. With increase of adding amount of sodium sulfide, suction filter time is growing, difficulty of row of salt enhances, and sodium sulphide remains in solution with continuing harm to production. It is necessary to apply oxidant to oxidize sodium sulphide to sodium sulfate to discharge more salts.