| 摘要 |
<p>PURPOSE:To recover Zn as ZnCl2 by dissolving waste Mn dry cells with a basic ammonium carbonate soln., then oxidizing the soln. to precipitate ZnCO3 and subjecting the soln. to a hydrochloric acid treatment. CONSTITUTION:The exterior packages of the used waste Mn dry cells are removed and the contents are put into a first dissolving chamber 4. The basic ammonium carbonate soln. 8A contg. 80 to 300g/l NH4 and 80 to 140g/l CO3 is put into this camber to dissolve Zn. The soln. is put into a first settling chamber 5 where the soln. is separated to a supernatant liquid 6A and a settled slurry 6B. The supernatant liquid 6A is put into an oxidizing chamber 7 where an oxide 12, such as air, is blown to oxidize the soln.; thereafter, the soln. is separated by a filter 13 to a filtrate 14B and settled cake 14A. The filtrate 14B is supplied to an ammonia distillation column 15 where the NH3 is released and the ZnCo3 is precipitated. The soln. is supplied through a filter 31 to a hydrochloric acid reaction vessel 18 where the Zn is made into a ZnCl2 slurry 21. ZnCl2 flakes 23 are recovered in a boiling kettle 22. The ZnCl2 flakes 23 are pulverized by a pulverizer 24 and are then sent to an Mn dry cell production stage 27.</p> |
