Abstract:With the increasingly strict environmental protection regulations and the need for green development of mines, the reuse of beneficiation wastewater is the only way for the development of mines. The reuse of beneficiation wastewater inevitably introduces residual agents, such as flocculant polyacrylamide (PAM), into the flotation process, which further affects the flotation of minerals, such as pyrite flotation. This study investigated the effect of anionic polyacrylamide (APAM) on the flotation behavior of pyrite and revealed its mechanism. The results showed that APAM significantly reduces the flotation recovery of pyrite, which was not conducive to the recovery of pyrite. A large amount of APAM was adsorbed on the surface of pyrite, which hindered the adsorption of the subsequent collector potassium ethyl xanthate (KEX), thus depressing the flotation of pyrite. APAM was chemically adsorbed on the surface of pyrite. APAM interacted with the Fe_³⁺ active site in the oxidation products (FeOOH, Fe₂(SO₄)₃) on the surface of pyrite through the amide group in the molecular structure, and then adsorbed on the surface of pyrite to depress mineral flotation.