Electrolytic method for recovery of lead from scrap batteries. Scale-up study using 20-liter multielectrode cell.
Lee-AY; Cole-ER Jr.; Paulson-DL
Rolla, MO: U.S. Department of the Interior, Bureau of Mines, RI 8857, 1984 Jan; :1-20
Prior work at the Bureau of Mines resulted in the successful development of a bench-scale, combination electrorefining-electrowinning method for recycling the lead from scrap batteries using waste fluosilicic acid (H2SiF6) as electrolyte. This paper describes larger scale experiments. Anodes cast from scrap battery lead were electrorefined in a 20-l multielectrode cell for 3 to 7 days. The anodes, containing 2 to 2.5 pct antimony, were ideal for obtaining firm and adherent slime blankets. Cathode deposits, assaying 99.99 pct Pb, were obtained, with current efficiencies near 99 pct. Sludge leaching was done in 100-l tanks followed by filtering in 61 cm square vacuum pan filters. Lead of greater than 99.99-pct purity was recovered from the filtrate by electrowinning in a 20-l multi-electrode cell using insoluble PbO2-Tti (lead dioxide-coated titanium anodes and pure lead cathodes. The fluosilicic acid electrolyte depleted in lead was repeatedly recycled to leach more sludge, and there was no problem with impurity buildup. The amount of PbO2 formed on the anodes during electrowinning was less than 1 pct of the total lead deposited on the cathodes, as long as the phosphorus concentration in the electrolyte was greater than 1.3 G/l. Emissions of lead in air were less than 10 ug/m3, well below the proposed OSHA limit of 50 ug/m3.
Materials-recovery; Lead-Metal; Electric-batteries; Electrowinning; Electrorefining
IH; Report of Investigations
NTIS Accession No.
Rolla, MO: U.S. Department of the Interior, Bureau of Mines, RI 8857