A process for the treatment of nacl - saturated, kcl -, mgcl deep 2 -, mgso deep 4 - containing, in order to obtain a solutions on mgcl deep 2 has been swivelled up aet preferential solution

摘要

Treatment of satd. NaCl solns. contg. KCl, MgCl2 and MgSO4, for the prepn. of a highly satd. soln. of MgCl2 contg. a reduced amt. of KCl, Nacl and MgSO4, plus high-grade KCl and K2SO4. The novelty is (a) soln. is decomposed with re-cycled carnallite salt to give a soln. contg. up to 300 g/l MgCl2 by enrichment with MgCl2 and also MgSO4 from the evaporated sa (b) KCl from (a) and the residual NaCl are removed as a moist decompsn. sa (c) soln. is heated to 90-130 degrees C and evaporated almost to saturation with KCl and NaCl, and re-cycled langbeinite seed crystals added to remove supersatd. MgSO4 so the soln. contains 25-55 g/l MgSO4; (d) the langbeinite obtd., free from NaCl and KCl is re-used in stage (c), and the soln. evaporated at 80-95 degrees C, cooled to 25-40 degrees C to obtain soln. and the salt for re-cycling. The conc. solns. of MgCl2 are used for mfg. Mg metal and Mg cpds.