Agree with that - we are all still learning but understanding...

Agree with that - we are all still learning but understanding the formula is critical when comparing deposits.  Whether coincidence I actually do get to their exact answer for the 2nd row, and in terms of the top row I get to their answer adjusting mass yield to 48% (using the red in the graph) hence why I feel the top line has an error given I get the exact answer on the 2nd row.  Unless it is a fluke. 

If you use the traditional method of calcs you might see in other minerals for getting to tonnes, you don't get the answers because what is been said is that the vanadium not in the magnetite is not recoverable in a vanadium process (which is different to what you might expect in other minerals hence the new concept of mass yield in vanadium).   I was hoping @Process1 might shed some light on what I did above (or anyone else) but understanding that diagram by AVL gives you a handle (albeit as I said whilst I get to the exact answer 2nd row, I don't on the first row unless I adjust mass yield - note the red bar in the diagram in the first row is nowhere near 60% so my confusion there and assumption). 

All IMO and rechecked over a VB