| 摘要 |
FIELD: metallurgy. ^ SUBSTANCE: procedure consists in separation of coal electrode and zinc cylinder, in flushing and dissolving in sulphuric acid. Also, flushing from ammonia chloride and zinc hydroxide is carried out with 0.2 M solution of sulphuric acid (H2SO4). Upon flushing residue of manganese oxide (IV) (MnO2), oxy-hydroxide of manganese (MnOOH) and coal mass (C) is crumbled in ball mills. Crumbled residue is dissolved in sulphuric solutions of concentration 0.05 mole/l containing 0.05-0.1 mole/l of oxalic acid at ratio of concentrations of ions of manganese and oxalic acid 1:5 at pH=1-2.2 and temperature of solution 80C. Upon dissolving solution is filtered for removal of coal mass. Residues of zinc ions are removed from solution with isoamyl alcohol of 200 ml volume at presence of 2 M solution of ammonia thiocyanate and 0.5 M HCl, and there is performed neutralisation with 0.5 M solution of caustic soda (NaOH). Further, produced solution is evaporated at temperature 100C to obtaining mass of crystalline compounds of composition sodium trioxalomanganate (IV) Na4[Mn(C2O4Çè2-)3] and salt of sodium oxalate (Na2C2O4). Produced mass is baked in atmosphere containing oxygen at temperature 400-500C with production of MnO2 as a final product. ^ EFFECT: raised efficiency and ecological safety of procedure. ^ 4 dwg, 3 tbl, 2 ex |
