RE: Curis extracts up to 89% copper from Florence ISR LABORATORY TEST RESULTS
Feed Leach Rinse Calculated Cumulative
Test No. H2SO4 cycle cycle head assay extraction
(g/L) (days) (days) (% Cu) (% Cu)
Box 1 5 152 43 0.46 47.47
Box 5 5 158 38 1.22 44.76
Box 9 5 186 46 0.77 63.51
Box 13 5 176 37 0.26 32.94
Box 2 10 151 77 1.00 88.72
Box 3 10 152 43 0.58 81.32
Box 6 10 151 77 0.32 71.68
Box 7 10 154 42 0.52 59.79
Box 10 10 134 78 0.36 63.54
Box 11 10 186 46 0.87 84.26
Box 14 10 134 78 0.42 47.79
Box 15 10 219 8 0.44 68.48
Box 4 20 152 78 0.49 34.74
Box 8 20 154 78 0.74 77.01
Box 12 20 176 37 0.45 48.30
Box 16 20 218 8 0.17 66.95
"These results suggest a mid-range sulphuric acid feed of between eight to 10 grams per litre is likely to be optimal for the Florence copper project to achieve maximum possible recoveries," commented Mr. Johnson.
ISR TEST RESULTS BY H2SO4 CONCENTRATION
Average feed H2SO4 Average extraction
(g/L) (% Cu)
5 47.17
10 70.70
20 56.75