If you go to the process flowsheet the initial phase of the ore feed facility is crushing and grinding with magnetic separation especially when you are seeking to get some byproducts out at that stage.
When you have one big pegmatite, you don't have a lot of overburden to remove and/or crap in essentially the screening process before putting them into the ore feed facility. In other words your ore feed becomes a lot cleaner.
When you have several smaller pegamatites/veins with crap in between the layers you can't always screen the lot out. Also, those systems generally have associated gangue, which at worst is a type of clay, or rubbish similar to that, which might be surrounding the ore or embedded between the veins where the body isn't complete. Some will always find its way into the ore feed facility.
The amount of and type gangue, and varibaility of it within the ore body itself, can impact recovery rates and what emerges from your initial cushing and screening stage after magnetic separation for example, before been fed into the more complex parts of the flowsheet, and if not removed to required specsit impacts teh process flow sheet itself. In other words, the pegamatite to gangue ratios/percentages impactsseparation of ore from gangue in the process flowsheet in the initial stages itself and how the 'recovery of the minerals' responses to that process differs depending on teh extent of gangue, for example.
By way of background, when you say an ore body grades 1.6%, what you are saying is 20% of the actual pegmatite rock is spodumene. If it is homogenous/consistent rock it can be dealt with in the processing/ore feed facility. If that rock has a lot of gangue/crap around/embedded within it, it can effect recovery and quality produced.
In terms of the MET tests themselves in my earlier post I am just wondering how the ore was prepared for those tests and how easily the initial preparation can be actually done in a working plant especially for those producers who have a series of viens to mine, rather than one thick pegmatite deposit (i.e. not in the lab). Having solid/large/dense pegmatite in a way does help the issue, and that benefits AVZ at this stage (and Greenbushes as well).
My head hurts as had one too many VBs writing that post so will switch off for a while and read.
Anyway hopefully the above is clear as mud/gangue.
