570
Y. Sakata
Fig. 1 Flow chart of Chigirishima Refinery
lead is mixed with crude lead from the blast furnace and treated in the copper removal
casting process.
The casted lead anode is refined in the electrolysis process (the Betts method), and
99.995% pure electrolytic lead is obtained. The anode slime containing silver, gold,
and bismuth is treated, and each element is recovered in the by-product process.
As for exhaust gas treatment, the SO 2 gas from the main reaction part of the
sintering process with high SO 2 concentration (>5%–SO 2 ) is treated in the sulfuric
acid process to produce sulfuric acid. The low SO 2 gas generated in the blast furnace,
cupola furnace, and cooling part of the sintering process is treated, and the gypsum
is produced in the desulfurization process.
The Minor Elements in the Waste Lead Battery
The Structure of the Waste Lead Battery
and the Disassembling Line
As shown in Fig. 2, the lead battery can be taken apart into six main parts:
– Lead alloy electrode grid,
– Strap lead alloy connecting the electrodes,
– Top part (the lead alloy external terminal),
– Lead paste (PbO 2 , PbSO 4 ),
– Dilute sulfuric acid electrolyte, and
– Plastic resin case.