摘要 |
<p>In a process for the fluidized roasting of finely divided iron sulphides, e.g. pyrites, the temperature and the ratio of oxygen to sulphide material are controlled so that the cinder obtained comprises magnetite and some sulphur is vaporized, and the cinder is separated from the roasting gases to which more oxygen is added to effect complete conversion of the vaporized sulphur to sulphur dioxide in the absence of the cinder. The cinder may be carried away with the roasting gases and separated therefrom in a cyclone separator before the sulphur in the gases is burnt on addition of further oxygen. If arsenic is present in the sulphide material it is vaporized and burnt with the sulphur after removal of the cinder.</p> |