Complete sepn. of metal-coated plastics and paper - by treatment at above 35 deg. C with soln. of strong electrolyte, pref. calcium chloride, followed by sink-float sepn. in same liq.

摘要

A sink-float process is claimed for the complete sepn. of metal-coated plastics or paper with particle size below 1.5 mm (I). The process involves treating (I) at above 35 deg.C with an aq. soln. of a strong inorganic electrolyte, pref. CaCl2 soln., which also serves as sepn. medium for the sink-float fractionation. Pref., aq. solns. of other strong electrolytes can be used, e.g. NaCl, NaNO3, MgCl2 or FeCl3, or a mixt. thereof. USE/ADVANTAGE - The process is useful, e.g. for sepg. waste materials contg. (I), esp. Al-coated plastic or paper packaging materials. A simple, low-cost, environmentally harmless process is provided for the complete sepn. of (I) with high throughput and low energy consumption (contrast prior-art processes using air separators, organic solvents, etc.). There is no chemical reaction with the electrolyte soln., and the sepd. component of (I) can be re-used without expensive purificn.