Recovery of Zinc and Nickel from Waste Phosphate Liquor.
U S Pat 3 649 220 1972 Mar; :
Zinc is selectively extracted from automobile assembly plant wastes in a batch or continuous process with di(2-ethylhexyl)phosphoric acid (I) in an organic diluent such as kerosine. Nickel is extracted from the raffinate of the zn extraction with dinonylnaphthalenesulfinic acid (II) in an organic diluent. The i exists as a dimer (rh)2 and zn(r4h2)org + 2h+aq results. The II exists as a polymer with ni x-2rx org and 2h+aq resulting. The ph of the solution should be between 3.0 and 4.0 For efficient zn extraction. Thus, a 100 ml solution containing zn 1.34, Ni 1.0, And po4 3.8 G/l was adjusted to ph 4.5 With naoh. A 100 ml volume of this solution and 100 ml of extractant of 20 vol pct I in kerosine was mixed in a 500-ml separatory funnel with mechanical shaking for 20 min. The organic and aqueous phases were separated and 100 ml of the extractant, comprising 8 vol pct of II in a 4:6 mixture of butyl ether and heptane are mixed with the raffinate from the zn extraction by the same procedure described above. The organic phases were then separately stripped with 100 ml of 15 pct h2so4 by mechanical soaking for 20 min in a 500-ml separatory funnel. A 99.5 pct zn and 98.5 pct ni extraction resulted.
U.S. Pat. 3,649,220; Mar. 14, 1972; Chem. Abstr. 76:144,654H