| 摘要 |
<PICT:0959227/C1/1> Metallic and metal complex ions are recovered from a slurry containing the same in insoluble form together with other insoluble materials by dissolving the metallic component contained in the slurry to form an ionic solution by the addition of a suitable solvent to the slurry; countercurrently contacting the thus treated slurry with an ion exchange resin capable of adsorbing the metallic or metal complex ion while agitating at such a speed that the upper and lower resin layers do not mix with each other and that no drifted flow occurs, the ion exchange reaction being carried out in a liquid passing vessel having a vertically suspended stirrer, and a hopper at its upper end for introducing ion exchange resin, a resin outlet at its lowermost part, a slurry inlet situated at its lower end but above the resin outlet and an outlet situated at its upper end for the overflow of treated slurry containing liquid; regenerating the resin having adsorbed the desired ions; and adding to the resulting solution containing said ions a precipitating agent for ions other than the desired ions and a flocculating agent to assist the precipitation. Copper can be recovered from the slurry resulting from the spinning step for the production of cuprammonium rayon fibre by adding sulphuric acid to the waste water containing copper ions from the spinning step which is placed in vessel 4 (see the Figure) and then passing the resulting copper-containing weakly acidic liquid upwardly through the liquidpassing vessel 1 which contains a cation exchange resin in the ammonium form. As the liquid ascends it is subjected to ion-exchange reaction with the resin which absorbs copper and other metal ions. The resin then passes from outlet 11 to water washing vessel 2 which is filled with water introduced at 14 and the washed resin is then passed to regenerating vessel 3 via outlet 15 and hopper 16. In the regenerating vessel the water-washed resin is countercurrently contacted with an aqueous solution of ammonium sulphate which is introduced at 17 and the regenerated resin ready for re-use is passed to hopper 10 of vessel 1 via outlet 18. Meanwhile the solution containing the desired ions overflows at the top of vessel 3 and is passed to purifying vessel 20 where it is treated with aqueous ammonia to convert the copper ions to tetramine copper sulphate while any other ions are precipitated. The mixture is passed to vessel 22 and a flocculating agent is added and as the precipitate formed deposits the copper to be recovered overflows as tetramine copper sulphate solution. The precipitate 9 is passed into dissolving vessel 4 to be recycled to effect the complete recovery of copper. Metal complex ions such as sodium bichromate may also be recovered using anion-exchange resins. |
