RE:Economics of lower grade sulphide projectsEndzone "Copper is produced low grade so why not nickel sulphide ?"
You are correct, nickel sulphide even in very low levels such as here, can sometimes be economically processed. The problem with the CNC cores is that in many of their cores there is ZERO sulphur. These are not sulphides, the small amounts of nickel present is locked in a silicate matrix and cannot be processed by conventional flotation. Where I work hign grade nickel ore is 2%. You should talk to a metallurgist.