It is good to see a thread with so much information. Considering...

It is good to see a thread with so much information. Considering that there are different battery compositions around and that there is a difference between scrap and black mass I think the following steps might be the way to go to market:

1. Immediate!: Scrap material can already be purified and recycled immediately. The growing number of giga-factories will have this sector alone already with a tremendous market size. This is a no brainer. Recycle the scrap at cheap price and but the anode material that has the exact specifications you want directly back into the production process.
2. Medium term: Focus on the recycling on black mass from a single battery type. There were several material tested initially. Which black mass gave the best results? Choose those and optimise until the material is ready to be used in the closed-loop again.
3. Redo with other types of batteries.

It might be that one will be able to find a "one fits all" purification step, it might however be that different batteries will need a slightly different purification set-up. As everyone is aware the amount of batteries produced in the next years will be ginormous. The amount of different battery chemistry will however be limited. So nothing speaks against having recycling lines / plants specific for each battery chemistry or anode material. Licencing might also be a very good option. One of the beauty of going down this path is that manufactures would be getting back exactly "their" anode material. Which might well be a quite specific mix of natural/synthetic.