| 摘要 |
1318422 Electrolytically producing MhO 2 NIPPON KOKAN KK 19 Aug 1970 [25 Aug 1969] 40006/70 Heading C7B MnO 2 for dry cells is produced by direct current electrolysis using an aqueous electrolyte comprising 10-40 g/lMn<SP>2+</SP> and 400-600 g/l free H 2 SO 4 at a temperature of 30-50‹C. and an anodic current density of 30-75 A/dm<SP>2</SP>. The resulting MnO 2 is subjected to a heat-treatment at 50- 100‹ C. for 0À5-4 hours in an electrolyte containing 400-600 g/l of free H 2 SO 4 . For the electrolysis, the anode may be of Pb, Pb alloy or PbO 2 and the solution may be agitated. Slurry containing MnO 2 and Mn<SP>3+</SP> may be continuously discharged from the electrolytic cell and filtered. The filtrate is heated to hydrolyze the Mn<SP>3+</SP> and produce more MnO 2 . Spent filtrate may be supplied to a leaching tank for preparing solution for electrolysis and some MnO 2 may be returned to the electrolytic cell as seeds. |
