Flotation cannot change the purity of the discrete graphite particle. i dont agree about your comment about grinding down to your hearts content since producing too small a particle size is both expensive and detrimental to recovery. Also what if the impurity is just as hydrophobic as the graphite surface? Your not going to separate these items by flotation.
The beauty of mns flakes is that the impurities are not finely intergrown within the graphite and thus dont need the chemical or thermal treatment steps to achieve the high purity grades outlined in their announcement. I don't believe the announcement is hype and the additional opex and capex costs (due to the more intensive floatation and longer milling times) have been factored into the bankable feasibility study which is one of the main reason we saw an increase in capex and opex between the prefeasibility and feasibility study
