Background

• This report has been based on my knowledge, without consulting Chalice or any of the other PGE coys – while my knowledge is dated, having mined these types of orebody underground with Implats in 1976/7, visiting/analysed them in Union Corp/Implats & Gencor Head Office & for brokers in South Africa, producing a ~100p guide to Sth Africa’s Platinum Sector in 1985, & a rating in PGE analysis to 1988, and again visiting and analysing in the early 2000s under Eagle Research/ERA in South Africa and Zimbabwe.
• From a few historic (then uneconomic for various reasons) possible PGE orebodies like FME / Future Metals’ Panton Sill, UFO (AIM) Alien Metals’ (after sale by ARV 70% & PGM 30%) Munni Munni, POD / Podium’s Parks Reef, and GAL / Galileo’s Jimberlana Dyke, recent PGE discoveries have been made in W Australia since 2020 by CHN / Chalice at Gonneville in March 2020, CPN / Caspin at Yarabrook Hill in May 2021 (both in the Julimar Province), and by GAL / Galileo at Callisto in May 2022 (near Jimberlana).
• Comparisons are being made on the basis of equivalent Palladium, equivalent Nickel, 2Es to 6Es, plus comparisons to Southern Africa’s PGE orebodies - and a number of analysts appear to be struggling to analyse orebodies that can produce 10 minerals, along with broad assumptions involving autoclaves and hydrometallurgical recovery of oxide material – whereas the standard Southern African treatment (for >50 years) is to ignore the oxide and float the harder rock sulphides to a concentrate.
• PGE orebody analysis can be simplified, its metallurgy / processing mostly simplified, production capability more easily understood, and comparisons between various PGE companies on a more level internationally understood playing field. This report focuses initially on analysis based on some assumptions applicable to most PGE orebodies, followed by more geological detail, mining and processing the possible “porridge-like magmatic orebodies”, that are very different to gold mineralisation.

1. Analysing a PGE orebody – eg CHN’s Gonneville.
1.1 Stockpile the Oxide :

• One of the possible misunderstood issues is viewing PGE mineralisation/orebodies like gold mineralisation - as in treat the oxide first and then the sulphide because of high recoveries in gold oxidation, whereas PGEs appear to be more like nickel mineralisation – ie altered/difficult to treat in oxide – with flotation recoveries often in the 30% to 50% area providing the PGEs haven’t altered to salts or the nickel altered to violarite and caught fire from spontaneous combustion when stacked on surface (I have seen it – it can cook/alter further too) - so PGEs in oxide are often stockpiled and possibly blended later. CHN has stated its oxide depth is ~25m (coincidentally the same as Implats Rustenburg, Sth Africa).
• PGE companies have usually targeted the main game – the higher grade “lodes” of sulphide mineralisation, and stockpiled or left behind the lower grade “porridge” between the higher grades. (Note : PGE described as porridge because the cooled “skins” of higher grade resemble cooling/freezing the top layer of boiling porridge - often contain domes, bubbles & potholes (from burst bubbles/domes).

1.2 Pick the Primary PGM and Compare :

• A typical PGE orebody has 6 PGMs (Pt/Platinum, Pd/Palladium, Rh/Rhodium, Ru/Ruthenium, Ir/Iridium & Os/Osmium) and Au/Gold for 7 PGEs, plus Ni/Nickel, Cu/Copper & Co/Cobalt. Comparisons with other PGE coys / orebodies are made on the basis of adding the g/t grades of the highest priced elements – hence 2E (Pt + Pd), 3E (Pt + Pd + Au), or 4E (Pt + Pd + Au + Rh), regardless of the different prices (Ru, Ir & Os are usually omitted because their prices are regarded as too low). A fairer comparison imo is to multiply the Rh grade by 8 and add it to the 3E grade for a 3E Equiv grade (though this is not common).
• Chalice has used Equiv(alent) Ni (possibly because it has higher nickel grades than Sth Africa, but few other PGE coys use that measure), and Equiv(alent) Pd for Gonneville – but again it’s not common - though some use Equiv Pt. However, the main comparison measures used internationally are 2E, 3E or 4E as in Table 1. Along with the Primary PGM based on Pt > Pd or Pd > Pt in g/t.