Lead paste was firstly desulfurized
with sodium carbonate, by which, the content of sulfur declined from 7.87% to 0.26%. Then, the desulfurized
lead paste was reduced by charcoal under vacuum. Under the optimized reaction conditions, i.e.,
vacuum thermal reduction at temperature 850 C under 20 Pa for 45 min, a 22.11 102 g cm2 min1
reduction rate, and a 98.13% direct recovery ratio of fine lead (99.77%) had been achieved, respectively.
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