| 摘要 |
<p>According to the invention the ore is subjected to a distillation in which the sulphur is liberated together with other volatile species such as arsenic, mercury, selenium, lead etc., and a pyrrhotite residue is left which is then digested with an acid to liberate three streams: one of H2S which is converted into sulphur, another which contains the dissolved iron salts and a third of insoluble matter; zinc sulphide, ferric oxide and the digesting acid are recovered from the iron salt solution, whereas the insoluble fraction is oxidised by sulphating roasting in order then to separate the copper, zinc and part of the iron, elements which are recovered by subsequent treatment of the solution, whereas the residual solid fraction from the leaching is treated with a solution of sodium chloride to separate the silver and lead, the first in the form of oxide or carbonate and the second in the form of sulphide or of metallic lead by cementation on a non-noble metal. The invention applies especially to metallurgy.</p> |
