GB114236A - Process for the Production and Separation of Ammonium Sulphate and Glauber's Salt. - Google Patents

Abstract

114,236. Dawson, H. M. May 12, 1917. Ammonium sulphate; sodium sulphate.-Ammonium sulphate and sodium sulphate are obtained by the absorption of ammonia in a solution of nitre cake or other acid sodium sulphate in water or water and sulphuric acid, and separation of the salts by crystallizing out the sodium sulphate at a low temperature and the ammonium sulphate after concentration. The concentration of the solution after neutralization is adjusted if necessary so that the ratio of water molecules to the molecules of the mixed salts is approximately 1000: 70-80. The solution is then cooled to about 10 to 15‹ C., Glauber's salt separating out. The mother liquor is then concentrated at about 100‹ C. when ammonium sulphate crystallizes out till the molecular ratio of ammonium sulphate to sodium sulphate reaches 2.7. If further evaporated, the salt deposited contains sodium sulphate, but the impure salt is still adapted for use as a fertilizer. If the ratio of sodium sulphate to sulphuric acid in the original solution is relatively high, a more concentrated solution may be employed for absorption of ammonia, and in this case a part of the sodium sulphate is deposited in the anhydrous form. Sodium carbonate or ammonia liquor may be added to the liquor from the saturator to neutralize it before cooling. The mother liquor from the crystallization of ammonium sulphate is suitably diluted and mixed with a solution which is to be cooled for separation of Glauber's salt.