St George Mining (ASX:SGQ) said flotation beneficiation testwork at its Araxá project in Brazil generated high-grade niobium concentrates with recovery rates that are comparable to industry standards, according to a Thursday filing with the Australian bourse.

The initial testwork comprised open-circuit flotation and achieved 39.6% niobium pentoxide concentrate grade at 54.3% flotation recovery, and 40.2% niobium pentoxide concentrate grade at 46% flotation recovery, per the filing.

Open-circuit beneficiation testwork also achieved a rare earth concentrate stream with a grade of 15.7% total rare earth oxides.

The next phase will include locked-cycle and recycle flotation testwork to optimize the beneficiation with increased recovery and grades, the company said.

Shares of St George Mining gained 2% in recent Thursday trade.