The purpose of this study is to address the problem of discharge of distiller waste from Solvay process, and at the same time, to realize the production of soda ash from Glauber’s salt — natural ores containing sodium sulfate, or industrial byproduct sodium sulfate. Half-saturated and near-saturated brines were prepared by reacting simulated distiller wastes — aqueous solutions containing calcium chloride and sodium chloride, with sodium sulfate. Experimental results show that the dissolution of sodium sulfate controls the reaction rate and the final composition of the brines. Temperature plays a key role in promoting the dissolution of sodium sulfate therefore to the reaction result, especially to the preparation of near-saturated brine. With equivalent sodium sulfate, more than 90 percent of the Ca2+ can be deleted. The precipitate (gypsum or anhydrite) can be used to produce cement or other construction materials.