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Metal Extraction from Aqueous Solutions With Liquid Emulsion Membranes.
Paper in Proceedings X Inter-American Conf on Material Tech San Antonio Texas, 1989 Apr; :8 pages
The Bureau of Mines is investigating a new technology involving the use of unsupported liquid emulsion membranes (lem) for the extraction of metals from aqueous solutions. A review is given of literature that describes the emulsion membrane technique and its possible applications both as a process recovery method for metals and as a waste water treatment method. Preliminary laboratory-scale research with lem for the extraction of cu from acidic dilute solutions (2.5 and 0.3 G/l cu) has yielded encouraging results. In single-stage batch tests, emulsion membranes extracted up to 94 pct of the cu from solutions without ph adjustment and 99.7 pct when the ph was maintained at about 2.5. Simulated two-stage crosscurrent and countercurrent circuit tests resulted in cu levels in the raffinates of only 3 and 4 ppm, respectively. These residual cu levels represent about 99.8 pct extraction from solutions without ph adjustment. An electrostatic coalescer is used to break the copper- loaded emulsion for recovery of the separated component phases. Up to 95 pct of the trapping solution (strip solution) containing the extracted copper was separated from the organic phase of the emulsion membrane. The recovered organic phase can be recycled without apparent problems.
Paper in Proceedings, X Inter-American Conf. on Material Tech., San Antonio, Texas, Apr. 17-21, 1989