Removal of heavy metals from solid or liq. effluents

摘要

Processing of solid or liq. effluents contg. heavy metals comprises: (a) treating a liq. effluent or liq. extract of a solid effluent with a reducing agent to obtain a process soln.; (b) contacting the process soln. with a solvent in a first extraction vessel, where the solvent is capable of selectively extracting heavy metals, anions and alkali(ne earth)metals and comprises an organophosphorus extractant and a hydrocarbon; (c) passing the organic phase from (b) to a second extraction vessel and contacting it with an aq. soln. capable of extracting heavy metals from the organic phase; (d) contacting the aq. phase from (c) with a pptn. capable of precipitating. all the heavy metals in the form of insoluble and vitrifiable chemical species; (e) filtering off the ppte. and washing it with water; (f) recycling the filtrate from (e) for addn. to the process soln. from (a); and (g) vitrifying the ppte. from (e).