The issues you have raised around tin/tantulum been a byproduct in the concentrate (i.e. a credit like cobalt credits in nickel concentrates) versus a separate product I think is a key issue, one which management will need to grapple with in a design/test capacity of the infrastructure it needs in a process flowsheet noting 6% grade spodumene needs to be low iron.
I cannot see tin/tantulum ever been recovered as a byproduct within the 6% grade spodumene concentrate itself that is sold to end customers - it will need to be a separate product (and the key here is to avoid double handling you need a technological solution so that you can attain both from the same ore within the same process flowsheet (not same facilities, facilities added to a spodumene faciity) rather than treating tailings to attain the other etc). That is there will be no recoverable byproducts within the 6% grade spodumene that is sold IMO.
I recognise @dr_manhatten
may have a different view but I feel this is going to boil down to a technological solution.
This question for tin/tantulum has never really been dealt with in a spodumene process because they have never been valuable minerals together in the past (as is the case now). Now, when I raised this issue many moons ago I did stipulate that there was movement in this field - i.e. trying to recover spodumene and other minerals in the same process (but sold as separate products - their own dedicated concentrates) as against treating tailings so as to avoid double handling - but test work incomplete (or not published). Refer to this post of April last year when I was a non holder - became a holder in July where I was doing some research into what some companies were doing in the area: Post #:
22762997
It really boils down to technological development, and I am sure it can be done because the concept of separation doesn't appear a difficult concept IMO. If you think about brine producers they can produce both potassium chloride and spodumene concentrate as
separate products from essentially the one process flowsheet, albeit the flowsheet itself has different stages/spheres within it, so I suspect it can be done here too.
The minimum I would be hoping for is that the initial screening and light scale crushing process of the initial ore fed into the process can initially be separated after that process into i.) principal spodumene ore; ii.) other, where other could contain spodumene and other mineral and iii.) possible junk.
Note: when someone says a core is 1.6% Li20 they are essentially saying 20% of that core is spodumene (theoretical core of spodumene is 8.03%, so 1.6/8.03 = 20%).
Principal spodumene category ore:
For this category, it would be a relatively straightforward process flowsheet that takes ore to the gravity separators or the grinding stage (note screening and light crushing has already occurred) depending on coarseness (and even if goes to grinding after that it would still end up going to the gravity separators). A key at the grinding and gravity separator stage is whether any of the residual tin/tantulum can be separated out to ultimately move to a
separate filtering process (rather than also end up in tailing from that process) where other concentrates such as tin can be produced/derived - PLS one to watch (see below).
The spodumene derived after the gravity separators itself goes to your stock standard separate floatation processes, including some form of magnetic separation at that point as well, from which ultimately your 6% grade spodumene is derived. Any tin/tantulum in the spodumene concentrate itself at that point, and there will be very little if any, will be deemed an impurity by end buyers IMO btw given the need to keep iron low (as high iron is a large cost to carbonate processors for removing it- it is not recoverable in the spodumene given the first stage of the roasting process in producing lithium carbonate is 1050 degrees celsius and the idea is to keep spodumene with low iron).
The other category and possible junk ore
Furthermore and where the bulk of the tin/tantulum units inthe ore will be IMO is in this 'other ore'. If AVZ has a technical solution in its process flow sheet in the normal course of events this would end up as tailings, but if don't want tailings then you need to develop technology within a process flowsheet at a high level that can further crush this 'other ore' and using various stages of Heavy Media Separation. The first obvious stage would be to send the crap to the tailings, whilst keeping 'anything good' within this secondary process (essentially outside the spodumene process). The second stage of the flowsheet would also involve sending the good grade spod you have also found in this secomdary porcess back into the grinding facilities (see above) that ultimately go to the gravity separators (see above) - in other words AVZ would want this secondary process in any event to avoid sending too much spod to the tailings as well because not all the ore that will be fed initially into the spodumene making process will be deemed great ore (albeit AVZ could surprise given its ore is actually quite high grade to start with). In this seperate secondary process attached to the spodumene process, you have dedicated filtering system to derive your tin and tantulum concentrate.
This is how I think PLS is prodominantly seeking to recover tantalite from its operation thus producing a tantalite concentrate and separate 6% grade spodumene from is process flowsheets (two separate products inconcentrate form). This will be an interesting test case (obviously they feel they have found a tech solution for that within the process flowsheet they are using to avoid double handling to get the maximum benefits from their ore feed).
As I said the technology is progressing, certainly PLS one to watch here given its process flow sheet is going to be unique, given at Greenbushes they use the different dedicated pit options etc etc.
Long winded post that might be useful or not. Anyway, the post took two VBs to write.
All IMO IMO IMO IMO IMO
