摘要 |
<p>Nonferrous metals such as Cu, Co, Ni, Zn, Mn, Col and Hg are recovered from an iron sulphide ore by a process comprising reacting the ore, sulphatising the nonferrous metals and leaching out their sulphates. The roasting of the ore is affected at 800-1100 degrees C in a fluidised bed to effect the oxidation of iron to F32O3 or Fe3O4 under controlled partial pressure of oxygen. The roated ore is then cooled to 600-750 degrees C (pref. 625-700 degrees C) and subjected to the sulphatisation process in another reactor (preferably in a fludised bed) in the pressure of sulphatising agents comprising iron sulphides, nickel sulphate, sulphuric acid and/or SO3 (the introduction of iron sulphites can be affected by incompletely oxidising them in the roasting stage; the metal sulphates can be supplied by recycling molten liquor from the recovery stage).</p> |