摘要 |
<p>The invention proposes a process for producing electrolytic lead and elemental sulfur from galena, characterized in that it comprises the following steps: (a) Galena is leached with an acidic aqueous solution of ferric fluoborate, with ferrous fluoborate, lead fluoborate and elemental sulfur being formed according to the reaction: 2 Fe(BF4)3 + PbS -> 2 Fe(BF4)2 + Pb(BF4)2 + S (b) the solid residue, composed by elemental sulfur and galena gangue is filtered off; (c) the solution of ferrous fluoborate and lead fluoborate coming from the (a) step is sent to a diaphragm electolytic cell, wherein pure lead is deposited at the cathode and at the anode ferrous ion is oxidated to ferric ion; (d) the solution of ferric fluoborate regenerated at the anode in said (c) step is recycled to said (a) step of galena leaching. By operating under suitable conditions, lead can be selectively dissolved and separated from the other metals small amounts of which are contained in galena together with said lead. Sulfur produced by the reaction can be separated from the gangue by extraction with a solvent, or by flotation.</p> |