Cobalt Demand, page-45

This issue is actually at the core of Mt Thirsty's mis-understood and under-appreciated market value.

The unusual nature of the MT deposit allows for a process design that is very cheap and fast, and millions of dollars have already been spent on independently conducted and audited studies and lab testing testing to prove this planned approach. Before this process was developed however Capex was going to be around $800million. Then with the revised approach that figure was reduced to $65-70 million. Unfortunately there is still a lot of old info around relating to the much higher capex - so it's confusing.

See below - the key bits are in bold. best to read through all the docs on the Mt T website to understand the whole picture.



3.1 Mineable Reserve

The geological resource to mineable reserve conversion rate for similar cobalt/nickel oxide deposits is typically 85%. This high conversion rate is due to the narrow grade range, considerable thickness and relatively flat lying disposition of this style of deposit. We anticipate a similar conversion rate at Mt Thirsty.

4. Process Development
Initial test work and flowsheet development was focused on low temperature atmospheric leaching of both cobalt and nickel at high acid concentrations which gave high metal extractions (+90% Co and +80% Ni) but at uneconomic capital and operating costs at prevailing metal prices (Solarbat: this was the 800mil Capex approach) . This work was carried out by Independent Metallurgical Operations (IMO) and is summarized below. During the test work it was noted in diagnostic analysis of feed and tails samples that 85- 90% of the cobalt was contained in the manganese mineral asbolane, which was less than 1% of the feed. Subsequent test work by RMDSTEM was then focused on selective leaching of this fraction of the ore using sulphur dioxide gas in an atmospheric, low temperature (<5oC), low time (<8hrs) agitated leach. Larger scale laboratory tests
confirmed the validity of this approach. The results of this work are summarised below.

4.1 IMO Testwork

In July 2009 the MTJV engaged Independent Metallurgical Operations (IMO) to perform a process development study which mainly involved metallurgical testwork, interpretation and flowsheet development. At the completion of the process development study in February 2010 a single flowsheet (Figure 7) had been identified and accepted for advanced process development. Testwork indicated this flowsheet was capable of extracting over 90% of the contained cobalt and around 80% of the contained nickel from the resource (Figure
5). IMO’s testwork was carried out on various bulk samples comprising drill chips, diamond core and material dug from shallow pits.

4.2 IMO Process Description and Flowsheet

A novel method for leaching the ore at atmospheric conditions was developed by IMO specifically for the Mt Thirsty Cobalt Deposit which has some unusual mineralogy compared to typical oxide deposits. Conditions are controlled within the leaching process to reduce manganese minerals contained within the ore while allowing leached impurities such as iron to precipitate as jarosite during the leaching stage. Jarosite precipitation allows removal of a major impurity from solution in a form which is easy to settle and regenerates acid. Downstream processing consists of separating the leach residue solids from the pregnant leach solution in a conventional counter current decantation circuit. The very good solid liquid separation properties of the leach residues produced allow for low flocculent consumption and high underflow densities.