Mineral sands is a margin business driven by revenue v costs....

Mineral sands is a margin business driven by revenue v costs.
The main issues are product quality and pricing, grade and assemblage. Scale is important too. Every mine is different but Iluka's model has been to seek margins from zircon, rutile and high grade ilmenite. It also produced synthetic rutile. They have small but high grade mines with good margins which require high annualised sustaining capital. Compare their EBIT and EBITDA numbers and you will see what I mean.
SFX are not in production and are closing in on a PFS so it's early days. But they are hoping for long life margins from zircon and lower grade ilmenite.
So other than being in Australia and the zircon they are different beasts.
The question of oversupply really comes back to product quality and production. If their zircon and ilmenite is good quality compared to its competitors then it will be sold and command a decent price. Only time will tell.
You need to do your own research but hopefully this is a starting point for you.