Key Success Factors for a Good Project, page-28

On a basic level, yeah that’s my understanding. It’s a little more complex than that though. The current processes mean that mechanical separation of impurities alone for BKT feedstock cannot produce battery grade graphite.
I can’t remember the exact source (it may have come from his patent), but FH mentioned that anywhere from 5-15 stages of cleaner floatation can produce a clean enough concentrate, whereas Nachu feedstock was somewhat unique in that it only requires three stages with less grinding.
The vendor selection test work with AUSENCO saw confirmation of the BFS proposed 99+%TGC concentrates and identified that additional stages of cleaner floatation could move the observed purity levels to 99.9%, in some cases meeting battery grade quality form the mine gate.
BKT may add further cleaner stages to their process flowsheet to produce higher quality concentrates, but at each stage there are additional variables to consider (for MNS too) i.e.

what impact does an additional cleaner stage have on overall costs per tonne (BKT’s process already has 4 stages of cleaner)?
how is the process recovery affected and would it require a higher ROM ore throughput to achieve equal quantity output?
what impact does excessive grinding have on the crystallinity?
trade-off between higher realised revenue (for higher purity) vs. higher processing costs etc…

What works in the lab is different to commercial scale and doesn’t necessarily translate. The lower increase to TGC% from the spheronising step for BKT’s feedstock compared to Nachu feedstock suggests to me at they are nearing the limit for what they can achieve mechanically without additional purification steps, at least at the commercial scale. There may yet be improvements though