To improve low-temperature flotation behavior of the refractory low-grade scheelite ores from Henan, a combined collector HQ-3 (95%FX-6+5%PEG-2000) was developed to enhance the low-temperature flotation separation between scheelite and calcium-containing gangue minerals, and then flotation tests were conducted to determine reagent regime suitable for such scheelite. On that basis, a closed-circuit flotation test by adopting a flowchart consisting of low-temperature roughing and high-temperature cleaning was performed at a temperature ranging from 5 ℃ to 10 ℃, with 1 800 g/t of sodium carbonate as the regulator, 750 g/t of water glass as the depressant and 260 g/t of HQ-3 as the collector in the roughing stage. As a result, a scheelite concentrate grading 28.06% WO₃ was obtained at 85.15% recovery. It is shown that compared with FX-6, the combined collector HQ-3 can improve the recovery of WO₃ from the roughing stage at a low temperature by 10.89 percentage points.

tungsten  /  scheelite  /  flotation  /  low-temperature flotation  /  FX-6  /  reagent compounding  /  HQ-3  /  tungsten concentrate  /  collector