race to the finish line, page-39

LTL,
Here are just a couple of points for you to ponder.
When people talk about grade in mineral processing plants they mean amount of payable mineral in ore or concentrate. They don’t mean value which is what you appear to be confusing it with.

The report you’re quoting is not necessarily correct in that it doesn’t always follow that the proportions of the valuable minerals are the same in feed as they are in concentrate, there are many reasons for this to be incorrect, to name just a couple there are grinding characteristics of the minerals in the case of flotation plants and mineral SG in the case of HMS plants. For the sake of CUX’s case we’ll assume the article to be more or less correct though – I’ll get back to this.

It does not also follow that lower FEED grade gives lower CONCENTRATE grade. Generally speaking what a lower feed grade means is that you will need more stages of concentrate cleaning to achieve the higher concentrate grade. What usually follows from that is the more stages of cleaning then the recovery of valuable mineral to concentrate will fall. Recovery to con is inversely proportional to concentrate grade, i.e. higher con grade, lower recovery and vice versa.

The importance of a higher concentrate grade is usually related to 2 things, transporting the con and tailings/waste for the refinery to dispose of. If CUX were to build a refinery at their mine, as an example, they probably would not be as keen to make a higher grade concentrate at the expense of recovery. Recovery is king – you get more from the ore that has a fixed cost to dig up and run through your plant. There is a definite point that is crossed though if you focus too much on recovery; it then becomes too expensive to recover the valuable metal from concentrate due to transport/treatment costs etc.
Now if CUX produces a 35% REO concentrate then they will still have 18% of that 35% as HRE.

So your maths has clearly gotten better, as it can be seen that 1 T of CUX con yields 63kg of HREO and 287kg of LREO. Viability, well who knows but having that proportion of LRE doesn’t make it unviable by itself alone. LYC has even lower proportions of HRE than that. Viability depends on many factors – how much ore you have, what grade is that ore, can it be mined economically, can the minerals be recovered in a payable manner etc.

The good thing CUX has going for it is that the ore DOES have a simple method of mining, needs no grinding circuit and has a fairly simple method of concentration and has plenty of ore. Whether they have enough grade in the ground to economically mine, build a plant and treat it is debatable. If we take the case of your beloved NTU, it is treatable, has a slightly more complex and more expensive method of treatment and so far they haven’t got a clue what the grade of the ore is or how much of it exists.

Both projects have question marks over them.