Laterite Leach Tests

Thickening and Vacuum Filtration Evaluation of Westmoreland Uranium Leach Residue Slurry
Laramide Resources
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5.2 Thickener Size Evaluation
Based on the static settling data detailed in Section 4.4, the dynamic settling data
detailed in section 4.6 the filter leaf test results, and the underflow slurry yield
stress results, the size of High Rate Thickener to process 30 t/h of Westmoreland
Leach Residue solids has been calculated. The results of these calculations are
summarised in Table 5.2.
Table 5.2 – Westmoreland Leach Residue - High Rate Thickener Sizing
May 2011
Parameters High Rate Thickener
Thickener Feed Tonnage t/h 30
Feed Solids % w/w 45
Feedwell Solids % w/w 7.5
Flocculant Addition Rate g/t 50 - 100
Free Settling Rate m/h 30
Rise Rate m/h 4.1
Underflow Solids % w/w 60 - 61
Underflow Yield Stress @ 60 – 61% Pa 14 – 19 Pa
Settling Flux t/m 2 h 0.38
Thickener Diameter m 10 m φ
Number of Thickeners 1
The testwork indicated the target feed rate of 30 t/h of Westmoreland Leach
Residue solids can be thickened to 60% – 61% w/w in a 10m φ Eimco High Rate
Thickener.
CONFIDENTIAL Page 15