| 摘要 |
<p>A process is described for the partial desulphurization roasting of a variety of zinc bearing sulphide ores or concentrates by adjusting the roaster temperature and residence time in the roaster thus providing an oxygen deficient atmosphere so that the required amount of sulphide retention is maintained. The obtained calcine or calcines are subsequently subject to various chemical and/or physical separation process steps to separate the unreacted sulphides which are, according to certain embodiments of the process, then dead roasted and treated for zinc recovery. In another embodiment, the separated unreacted sulphides are again partially desulphurized in an oxygen deficient atmosphere for subsequent treatment to recover zinc, lead and precious metals. The chemical separation process steps include aqueous sulphur dioxide treatment, dilute sulphuric acid solution treatment and treatment with dilute sulphuric acid containing sulphur dioxide in solution, all conducted in the temperature range of 50 to 75°C. Physical separation process steps include one or more of the flotation and magnetic separation techniques although other physical separation steps may also apply in some instances.</p> |
