HEMATITE PRECIPITATION AT ELEVATED TEMPERATURE AND PRESSURE

摘要

A hydrometallurgical method (10) for precipitating iron as hematite at elevated temperature and pressure from a pregnant leach solution ("PLS") (12) containing nickel, cobalt and iron, the method comprising the steps of: (i) leaching a low to medium grade nickel laterite ore to produce a PLS (12) containing nickel, cobalt and ferric iron; (ii) subjecting the PLS (12) to elevated temperatures and pressures for a time sufficient to precipitate iron as hematite; (iii) passing the product of step (ii) through a solids/liquid separation circuit (26) to substantially remove the hematite precipitate, and produce a substantially iron-free, acid containing solution; and (iv) recovering nickel and cobalt from the final substantially iron-free, acid containing solution.