Journal of Chemical and Engineering Data, Vol.57, No.5, 1449-1455, 2012
Solubilities of Ammonia and Ammonium Chloride in Ammoniated and Nonammoniated Methanol and Ethylene Glycol between 298 K and 353 K
The solubility of ammonia (NH3) and ammonium chloride (NH4Cl) in the systems NH3-CH3OH, NH3-C2H6O2, NH4Cl-CH3OH, NH4Cl-C2H6O2, NH3-NH4Cl-CH3OH, NH3-NH4Cl-C2H6O2, and NH3-NH4Cl-C2H6O2 + 8 % CH3OH are reported for temperature conditions relevant to the crystallization of pure magnesium chloride hexammoniate (MgCl2 center dot 6NH(3)) within the Australian Magnesium (AM) process. The solubility of NH3 in anhydrous methanol and ethylene glycol decreased within the temperature range 298 K to 333 K. The solubility of NH4Cl in methanol increased from 3.3 % at 298 K to 3.7 % at 313 K, and in ethylene glycol the NH4Cl solubility increased approximately linearly with temperature between 313 K and 353 K extending from 9.7 % to 11.9 %, respectively. The solubility of NH4Cl in saturated ammoniated methanol at 298 K was 7.9 % with a corresponding NH3 content of 15.0 %. At 313 K it was 5.5 %, while the NH3 content was approximately 9 %. The solubility of NH4Cl in saturated ammoniated ethylene glycol at 313 K, 323 K, and 333 K was 11.0%, 11.7%, and 13.2%, respectively. The results for the systems NH3-NH4Cl in C2H6O2 and CH3OH indicate that minor amounts of NH4Cl, formed during MgCl2 center dot 6NH(3) crystallization, will dissolve in ammoniated ethylene glycol and ammoniated methanol and ensure an NH4Cl-free hexammoniate product.