Are you suggesting that Ardea is misleading investors by...

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Solarbat

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12/04/22

14:31

Post #: 60808630
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Originally posted by Blythefan: ↑

The Murrin, Cawse, Bulong and other WA komatiite hosted laterites have poorly differentiated limonitic caps with low magnesite but low nickel. The saponite/nontronite/smectite clay in the lower saprolite has higher Ni (to 2%) but MgO of 12%+. At Murrin Murrin, the HPAL autoclave is designed on a blend of these two ore sources, where low acid consumption limonitic laterite is blended with high Ni, high MgO saponite to achieve a good overall Ni for any given acid consumption.

Limonitic laterites consume less sulphuric acid, and can be leached better at low temperature and pressure. The saponite laterites require HPAL. This is because it's essential to remove potassium and aluminium via precipitating jarosite at high pressure and temperature, to remove Fe, K, Al. These elements are a problem when trying to precipitate the Ni-Co metal hydroxides via adding CaO or MgO in the subsequent stage.

Ardea has, itself, a two pronged metallurgical strategy for its laterites where, allegedly, they will have atmospheric leach for the ores that are amenable to it, and HPAL for those that aren't. I cannot say if this is the correct processing strategy. However, there was a open collaborative CSIRO research project on dealing with MgO content in laterites running last year (amongst other issues) and there are some potential solutions to MgO consuming acid, but none of these are commercially ready.

However, my criticism isn't on whether Ardea's laterites will consume >550kg/t H2SO4. It's how the hell they can have a 'magic pudding' situation with REE's, titanium and 'rare metal oxides' in the HPAL process.

The rusted-on barnacles here will blithely ignore the chemistry here, but for example, titanium doesn't readily precipitate away from iron in the sulphuric acid system. Not that anyone should care too much about 800ppm-8,000ppm titanium oxide in the ore. The REE's, if they are indeed present as alkaline volcanic intercalations in the sequence, will be attached to the laterite FeOOH/MnOOH mineralogy, and could possibly be extracted, but they will extract alongside the Ni,Co....K, Al, Fe, Mn, Mg...etc. Separating them explicitly from the leach liquor at high purity is a bit of gymnastics yet to be accomplished.

Even worse is the inclusion of zircon, hafnium and Nb-Ta. No one extracts these with HPAL.

But yeah, as the barnacles say, Ardea "has done some tests". Whoopty doo. Well, guys, what are the results? On what basis does Ardea believe that REE's, or TRMO's are significant intercepts worthy of reporting?

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Are you suggesting that Ardea is misleading investors by downplaying or ignoring worrying issues that could make the project non-viable?

Are you suggesting that state and federal gov agencies who have given their support to Ardea, including the CSIRO, have not done their due diligence? Have not had their mining experts thoroughly examine and assess the project for viability?

Both seem highly unlikely.

ARL Price at posting: $1.81 Sentiment: Buy Disclosure: Held
11 Upvote

2 Great analysis

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