Lopoliths and carbonatite pipes...15 Mar 2018 10:33
1. Given the TREO (total rare earth oxides) figures that Rainbow have released (47% to 67%), the narrow veins currently being mined must be almost pure bastnasite, with only a little monazite and a few impurities mixed in.
2. If the Kiyenzi lopolith checks out, all 500,000 tonnes of it, there's every reason to suppose that it is made up of more or less the same stuff as the narrow veins (and the boulders discovered downslope nearby). It really would be a billion dollar rock - even using pretty pessimistic assumptions, I calculate that Rainbow would make more than $400m pure profit from simply digging it out, grinding it up, and selling it as concentrate.
3. The four carbonatite pipes (intrusions of magmatic material) also being drilled will contain at least 50% carbonatite material (by definition) plus silicates. We can hope for yet undiscovered rare earth mineralisation as vein systems on the aureole of the pipes and also rare earth presence inside the pipes. But, inevitably, this will grade lower TREO than the current vein systems, and it will probably require a more industrialised kind of mining and a more complex processing plant. It's just possible that the carbonatite pipes also contain some other valuable elements in commercial quantities - such as niobium, tantalum, or thorium.
4. The carbonatite pipes are sizeable objects - the biggest has a diameter of approx. 2700 metres. Their thickness for now is unknown, but judging by comparable examples, they could easily drop down 100m in a rough funnel shape. So though the grade may be lower, the actual amount of rare earths the pipes contain may be very large.
As always, grateful for any feedback.
The company is presenting next week (22nd, I think) at a Proactive Investors evening. It's just possible we may get an RNS with partial drill results before that. It would certainly give them something to talk about!