Recovery of ammonium sulphate - by treating waste sulphuric acid from acetylene purificn. with ammonia until no more impurities separate out

摘要

The recovery of ammonium sulphate (I) from waste sulphuric acid (II) resulting from the purification of crude acetylene obtd. from calcium carbide which has been washed with sulphuric acid and which contains water, phosphoric acid and with inorganic impurities like sulphur cpds. comprises (a) reacting with 40-70% of the amt. of ammonia needed for complete conversion to (I), until a 2nd liq. phase has formed which contains the organic cpds. and which forms above the (I) and (II) rich phase; (b) sepg. the two phases; (c) further reacting the (I) and (II) rich phase with ammonia until almost complete conversion to (I). The process utilises the dark-brown to black, unpleasant-smelling waste (II), resulting from the purification of crude acetylene.