Laterite Leach Tests

ANSTO Minerals Report C1206 to Lagoon Creek Resources – Westmoreland Deposits
For most elements, the actual solution values are close to the weighted averages after 24
hours. The exceptions are as follows:
• Higher Fe: as mentioned earlier this was due to the mild steel grinding media and mill
components partly dissolving in the leach.
• Higher Mn: due to pyrolusite being used as the oxidant.
• Lower Na: in the individual tests LC5 C and LC6 B sodium permanganate was used as
the oxidant, thereby artificially raising the sodium levels in the product solutions.
• Higher S: due to the extra acid added due to the metallic iron dissolving. Also
pyrolusite dissolution consumes acid, thereby increasing the sulphate tenor of the
solution.
5.3.2 Vendor Settling and Filtration Results
A summary of the FLSmidth settling test results are given in Table 5.5 (and compared with
the ANSTO settling test results) and a summary of the filtration test results are given in Table
5.6. The detailed report from FLSmidth has been included as Appendix J.
TABLE 5.5
Settling Test Results
Parameter FLSmidth Junnagunna Redtree
Thickener feed tonnage (t/h) 30 30 30
Feed solids (wt%) 45
Feedwell solids (wt%) 7.5 7.5 6.6
Flocculant addition rate* (g/t) 50-100 62.5 71.6
Flocculant type 800HP E 10 E 10
Rise rate (m/h) 4.1
Free settling rate (m/h) 30 5.9 5.9
Expected underflow solids (wt%) 60-61
Underflow stress yield (Pa) 14-19
Flux rate (t/m 2 /h) 0.38 0.103 0.142
Thickener diameter (m) 10 19.3 16.4
Number of thickeners 1
* Magnafloc 800HP for FLSmidth tests, Magnafloc for ANSTO tests
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