hydrometallurgical method for precipitation of iron in the form of hematite from bleach solutions containing nickel, colbate and iron

摘要

HYDRO-METALLURGICAL METHOD FOR THE PRECIPITATION OF IRON IN THE FORM OF HEMATITE FROM SOLUTIONS OF LEATHER CONTAINING NICKEL, COBALT AND IRON, as it is a hydrometallurgical method for the precipitation of iron in the form of hematite from leach solutions containing nickel, and iron, characterized by the steps of: i) pre-neutralization (12) of the bleach solution with the addition of a neutralizing agent (14); ii) oxidation of ferrous sulphate to ferric sulphate (16) spreading air or oxygen in the solution resulting from step (i) at high temperature; (iii) adjustment of the free acid and pH of the solution resulting from step (ii) at levels suitable for the precipitation of hematite; iv) addition of hematite granules in the solution resulting from step (iii), keeping the solution in these conditions for a period of time such as to substantially complete the conversion of ferric sulfate to hematite precipitate; v) filtration or thickening (24) of the solution from step (iv) to remove the hematite precipitate; vi) recycling a portion of the hematite precipitate from step (v) to step (iv) as hematite granules; and vii) recovery of nickel and cobalt (26) from the filtered solution.