The selective depression effect and mechanism of the organic depressant sodium dimethyl dithiocarbamate (SDD) on pyrite in the flotation system of chalcopyrite and pyrite at low alkalinity (pH 8.5) were investigated. The results of single mineral microflotation tests indicated that the recovery efficiency of pyrite decreased from 80.23% to 39.18% after SDD was added, while the recovery efficiency of chalcopyrite decreased from 97.74% to 93.07%. This indicates that SDD has a clear selective depression effect on pyrite, but it has little depression effect on chalcopyrite. X-ray photoelectron spectroscopy (XPS) showed that at low alkalinity (pH 8.5), SDD chemical adsorbed on the surface of pyrite to form water-insoluble complexes, the flotability of pyrite surface was decreased. However, adsorption of SDD on the surface of chalcopyrite was weaker than that on pyrite, which increases the flotability difference between the two surfaces and leads to selective depression of pyrite.

研究了低碱度（pH 8.5）黄铜矿和黄铁矿浮选体系中有机抑制剂二甲基二硫代氨基甲酸钠（SDD）对黄铁矿的选择性抑制作用及机理。单矿物微浮选试验结果表明，加入SDD后黄铁矿的回收率从80.23%下降到39.18%，而黄铜矿的回收率从97.74%下降到93.07%。这表明SDD对黄铁矿有明显的选择性抑制作用，而对黄铜矿的抑制作用很小。X射线光电子能谱（XPS）表明，在低碱度（pH 8.5）下，SDD化学物质吸附在黄铁矿表面形成不溶于水的络合物，降低了黄铁矿表面的可浮性。然而，