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Abstract

Raw lead to be refined, whether of mineral origin or from reclaiming operations, the particle size of which has been reduced to a range not larger than 50 mm, is leached in a suitable apparatus with a solution of ferric fluoroborate in fluoroboric acid. During the leaching step, lead is dissolved, with ferric fluoroborate being reduced to ferrous fluoroborate according to the following reaction: 2Fe(BF.sub.4).sub.3 +Pb.fwdarw.Pb(BF.sub.4).sub.2 +2Fe(BF.sub.4).sub.2 The leaching apparatus behaves as an external anode installed outside of the cell. The solution resulting from the leaching step is sent to the cathodic compartment of a diaphragm cell in which lead is deposited on a cathode of stainless steel, in compact, highly pure form. The solution that is depleted of lead then is sent to the anodic compartment of the same cell, in which a suitable anode oxidizes ferrous fluoroborate to ferric fluoroborate that can be regenerated to the leaching step.

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