| 摘要 |
<p>1,144,716. Concentrating rhodium solutions. USTAV NEROSTNYCH SUROVIN. 22 March, 1967 [29 March, 1966], No. 13336/67. Heading C1A. Acid solutions containing low concentrations of rhodium are concentrated by passage through an anion exchange resin in hydroxyl or weak acid form. The resin neutralizes the acid and precipitates the rhodium as a band of rhodium hydroxide and basic rhodium salts which progresses down the column by dissolution in further acid and precipitation on subsequent layers of resin. In this way the rhodium is concentrated into a band on the resin and may be recovered as cationic Rh by eluting with either more acid rhodium solution or dilute sulphuric acid, the resin being subsequently regenerated. The rhodium concentrate may be eluted on to a second similar column to which further such concentrates from the same or different first stage columns are subsequently added producing a still more concentrated band from which the rhodium may be recovered as above. The solutions treated may be rinsing waters which have been used for rinsing objects removed from an electrolytic rhodium plating bath. The rhodium free solutions obtained from the bases of the columns may then be recycled to the rinsing stage.</p> |
