@dawgfather Sorry but I don't agree with your interpretation that LRS has an 80% recovery rate.
On my reading of the report LRS did well in only losing 12% of the material as fines (and 10% of the lithia units). 88% of the material and 90% of the lithia unit were then put through HLS tests where there was then a recovery rate of 80.5%. Of course LRS would put an emphasis on this 80.5% figure but the key words are bolded "
Heavy Liquid Separation (“HLS”) was able to recover an average of 80.5% of the Li2O into a concentrate grading a very high average of 6.30% Li2O" IMO this recovery rate is of the material presented to the HLS test, not of the overall material including fines. I made the same interpretation mistake on the first few HLS test reports I'd read until I realised what was happening. This is incidentally why if you look at any multi-project comparative recovery rate chart its only DMS+Flotation or Flotation only that gets to 78-80% recovery rates. To achieve 80.5% from DMS only you would both need both fines down at 10% or less and circa 90% DMS recovery rates. I've seen a project with over 90% modelled HLS recovery rates but they had 20.9% of the lithia units lost as fines and were therefore "only" reporting a 72.6% overall recovery rate.
To get back to the LRS project recovery rate you need to factor back in the 10% of lithia units from which there is a 0% recovery rate - the fines that won't work effectively in a DMS circuit. Once this is done you get back to a very respectable 72.45% recovery rate for LRS which is incidentally very close to what Core modelled in its DFS (71.7%). Some commentators suggest lowering the test results by a few percent to reflect real world rather than lab result conditions. I'm sure you can see what would happen if you took a few more percent of 72.45% and how it would compare to Core's DFS. The problem is that sometimes these DFS results are not replicated in reality and the gap is wider than just a few percent and that's the issue facing Core.
If Core started with 1.4% material and had 40% as 1.1% fines, then its also got 60% as 1.6% crushed material ready to go to the DMS. An annoyingly high 31.4% of the lithia units are lost as fines (.44/1.40). If there is a 70% recovery rate from this crushed material then the overall recovery rate is 48%. Original ore: (40*1.1%+60*1.6%)/100=1.40%. Material entering the DMS 60*1.6%*70%=0.672. Overall recovery rate 0.672/1.40=48%.
If Core can improve the DMS performance from perhaps 70% in the theoretical example above to 80% then it would match the HLS test results that LRS reported. That would however only pull recovery rates up to 55% due to all the fines. To get them higher needs either less fines or recoveries from the fines.
