| 英文摘要 |
The first-year projects of this research studied the best parameters of separation technologies of physical sieving and selective precipitation employed to recover the zinc-manganese powders from wasted zinc-manganese batteries and alkaline batteries. Examined data from our laboratory of zinc-manganese powder resulted in 4.8% of organic residues, 42.65% for manganese (55.06% of manganese dioxide equivalent), 26.66% for zinc (33.17% of zinc oxide equivalent), 6.97% for others oxides (mainly potassium, iron, silicon, et al.). The best roasting condition is 750℃ for 1 hour. The produced zinc-manganese powders could match the quality specification of soil conditioner or fertilizer, once the magnetic separation process lower the content of Fe below 1%. Sieving process with 200 mesh screen produced partitions with weight ratio 6:4 of larger particle size partition and smaller particle size. The larger particle size partition is high-zinc-content which composed of 27-29% of zinc, and the smaller particle size partition is high-manganese-content which composed of 38-52% of manganese. The selective precipitation process used 6% NH4OH as precipitation agent. Ferrous ion was precipitated at pH 4. After filtration the supernatant liquor was adjusted to pH 7, and zinc ion was precipitated as zinc hydroxide until pH 7. After another filtration, the supernatant liquor was adjusted to pH 10 along with increasing the temperature up to 40℃, and also included the addition of H2O2. Meanwhile the manganese ion was precipitated as manganese hydroxide until pH 10. The recovery ratio of zinc and manganese was 88.64% and 86.90%, respectively. The purity of zinc and manganese was 94.63% and 98.17%, respectively. The technologies developed by this research can also be applied to the separation and recovery of other mixed metal waste.
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