The latest info on G-200 HP (from Mike Tkach at Homer Laughlin ) is:
The official letter from Imerys has been published stating that the Monticello plant will be closing at the end of the year and G200HP will be gone.
The beneficiation of the soda spar into potassium spar at Spruce Pine did not work out. The plan to bring in feldspar sand and process it in GA did not work out.
They are bringing in 200m spar from Spain in 25kg and short ton bulk bags. You better have a fat wallet as the 25 kg bags are $450/short ton plus delivery.