Laterite Leach Tests

ANSTO Minerals Report C1206 to Lagoon Creek Resources – Westmoreland Deposits
tests on Junnagunna and Redtree where uranium was still being leached after 12 hours. This
may be due to the elevated iron levels in solution enhancing reaction kinetics.
Residue Grade (ppm U 3O 8)
300
250
200
150
100
50
0
0 5 10 15 20 25 30
Leaching Time (h)
Junnagunna Redtree Bulk Composite
FIGURE 5.2 Residue Profiles at 550 mV
The final solutions for the individual tests are compared to the bulk leach final solution in
Table 5.4.
The Bulk Leach was conducted over 12 hours, whereas the leaches on the individual ores
were conducted over 24 hours. The expected final solution values were calculated using the
analyses from the individual tests and the fraction of the ore used to make the composite, to
produce a weighted average. When the weighted average after 12 hours is compared to the
actual bulk leach solution it can be seen that, generally, the expected value from the weighted
average is lower than the actual bulk solution, and that the values are much closer when the
weighted average after 24 hours is used. The reason for this is unclear.
TABLE 5.4
Product Solution Comparisons (mg/L)
Test Time Al Ca Fe Fe 3+ K Mg Mn Na P S Si U
Junnagunna LC5 C 12 h 506 388 3017 2882 152 247 680 359 63 6700 592 1233
Redtree LC6 B 568 193 2620 2461 160 162 662 317 41 6630 632 1351
Jack LC16 A 158 107 1310 759 112 34 58 49 47 2788 231 803
Junnagunna LC5 C 24 h 804 427 4020 2499 272 369 657 380 66 7870 681 1417
Redtree LC6 B 698 204 3090 1902 248 195 579 291 42 6260 580 1473
Jack LC16 A 228 120 1427 846 172 32 98 65 41 2788 231 803
Bulk leach Actual 12 h 609 312 5350 5016 236 170 3750 86 79 9910 589 1208
Expected* 12 h 422 227 2339 2066 143 149 481 247 50 4982 406 1234
24 h 586 248 2866 1762 232 199 454 249 49 5688 503 1248
* weighted averages from individual leach tests
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