Hallo Ihuazai
Spodumene has a density of about 3.3 and is (in Bald Hill's case) a dull white/pale green in colour. Pegmatite tailings is brilliant white and has a density of 2.5. DMS is able to very accurately split -25mm+1mm product into a floats and a sinks fraction because the density difference between the two is quite large (0.8 units) The only time there is blurring in the products is when particles containing both minerals enter the cyclone (spodumene occluded within pegmatite matrix) The way to recover this is to recrush floats middlings.
All -1mm is NOT amenable to conventional DMS. It has to be presented to a flotation circuit, in which small bubbles are injected into a slurry mix and reagents added which will cause -1mm spodumene particles to adhere to the bubbles and flow over into a flotation cons circuit.
Paradoxically, lithium itself is so light, it will float in water (density less than one) but its ore is denser than the host rock. The -1mm material can also be recovered by spirals, producing an ultraheavy stream (tin, tantalum and niobium) a heavy stream (spodumene) and a light stream (90% by mass of pegmatite).
I would also strongly advise you to look at Greenbushes, on the Darling Scarp, about 200 kms south of Perth, They have been mining hard rock spodumene for over thirty years and they have always made a handsome profit.