t of solids and as can be seen from fig3 amp 4 nickel extraction was greater than 50 while cobalt extraction was 55 for the finer size 75 u03bcm 1 mm reject material and 35 for the coarser size 1 6 mm reject material in both cases the extraction of both nickel and cobalt was still increasing after 14 days the nickel and cobalt tenor of the pregnant solutions is high reflecting the good extraction levels achieved these along with the major impurity levels are shown in table 2 solution concentrations approaching 5 g l ni are comparable with those obtained from the hpal process or the atmospheric leaching process and this solution would be directly applicable to feed to a solution purification and hydroxide precipitation circuit with remaining metal values of 0 25 ni and 0 013 co in the heap leach rejects this represent 75 and 70 nickel and cobalt recovery respectively after taking into account the original beneficiation recovery of around 57 5 and 45 8 respectively and is a major improvement in overall recovered metal from the ore the size fractions of the laterite ore beneficiation low grade rejects samples used in example 1 were recombined in their respective proportions in the original ore for the following testwork to produce a test sample for both the limonite and the saprolite low grade rejects the analysis of the composite samples is shown in table 3 samples of each reject limonite and saprolite ore were loaded.