Abstract: There is high content of calcic gangue mineral in a low grade tungsten and molybdenum ore in Luanchuan Henan，the efficiency of scheelite roughing from the tailings of molybdenum separation at room temperature is very low，which greatly increases the reagent dosage of heating selection and increases the difficulty in improving the grade of WO₃ in concentrate.Experiments on the inhibition effect of sodium silicate，acidified sodium silicate and ATM respectively，and the synergistic effect of the acidified sodium silicate with ATM are carried out.The results show that the order of inhibition effect is ATM > acidified sodium silicate > odium silicate，when the three kinds of inhibitors are used alone；ATM and acidified sodium silicate used at the same time can play a synergistic effect.With the dosage of ATM + acidified sodium silicate 20 + 300 g/t，and compared that with no use of the inhibitor，the rough concentrate grade of WO₃ increases from 0.62% to 1.42%，and the recovery increased significantly，which creates conditions for improving the quality of concentrate and reducing cost subsequently.

Key words: Scheelite roughing, Rough concentrate grade of WO₃, Composite inhibitor, ATM+acidified sodium silicate