Nickel/copper recovery - from iron-contg sulphides by oxidising in aqs suspension

摘要

Ni in Ni-contg. sulphide minerals is separated from Cu sulphide minerals, both minerals being present in combination with Fe sulphides of formula FexSx+1 (where x is 1) by (a) forming in an autoclave an aqs. suspension of Ni, Cu, and Fe sulphide minerals, (b) pressurising the suspension with a free oxygen contg. atmos. having a partial oxygen pressure of =3 esp. 3-30 at. (c) holding the suspension at 80-110 degrees C (d) maintaining the suspension in intensive motion to form a uniform dispersion of solids, ensure max. oxygen transfer from the atmos. to the aqs. suspension, selectively convert iron sulphides into elementary sulphur and iron oxide, and the Ni-contg. sulphides into N sulphate, which dissolves in the aqs. suspension, (e) terminating the oxidn. reaction after a considerable part of the Fe sulphides and Ni-contg. sulphides are oxidised, while the Cu sulphides remain essentially unoxidised, (f) recovering Ni from the Ni sulphate soln. and (g) recovering the Cu sulphide minerals to produce a Cu sulphide mineral concentrate of good quality.