| 摘要 |
<p>Zinc is recovered from zinciferous mineral sulphides by a process which comprises the steps of dispersing the sulphide in the form of particles in an aqueous acidic sulphate solution to form a slurry, adding sulphuric acid to the slurry to provide sufficient free sulphuric acid to combine with the zinc content of the sulphide as sulphate, reacting the slurry with a free-oxygen containing gas at a temperature below the melting point of sulphur, preferably between 90 DEG C. and 112 DEG C., and under an oxygen partial pressure of above 0,3 atmospheres continuing the reacting at a pH below 2,5 to extract the zinc from the sulphide to form a solution of zinc sulphate, with concurrent oxidation of sulphide sulphur to elemental sulphur, separating elemental sulphur and undissolved residue from the zinc sulphate solution, and recovering zinc from the solution as the metal, for example by electrolysis. The elemental sulphur may also be separated, for example by melting and filtering, and the remaining sulphides returned to the oxidation treatment. Alternatively the slurry may be heated to above the melting point of sulphur after the oxidation to form molten sulphur globules, cooled to solidify the globules which are then separated from the slurry, and the zinc sulphate solution then separated from the undissolved residue.</p> |
