Van Uden Met test work

Starting a new tread for those interested in historical Gold met test work around recoveries.

Amdel Limited Mineral Services prepared a report in April 2000 that used samples from VUDDH_001 to VUDDH_008. The full report including the individual assay cross-match to the samples is part of the Mindex WAMEX set of reports - Report 61839 for Sep 1999 to Aug 2000.

The TLDR version is that the Van Uden ore has consistently achieved >90% recovery rates if the material is ground to a small particle size like P80 and subjected to bottle roll leach tests. Most of the time recoveries have hit 90% within 8 hours but the laterite sample took the 24 hour period to reach 97% recovery rates. Testing with larger particle sizes has seen a large and sometimes massive drop-off in the recovery rates. Column tests that would replicate heap leaching also have lower recovery rates.

The difficulty of crushing to P80 is its more expensive, however the higher the gold price the less this incremental cost becomes an issue. At current gold prices I suspect the economic option is to take all reasonable actions to maximise recoveries so the optimal choice is transportation to a mill with fine size crushing capability and then achieve a mid-90's recovery rates available from the ore.