Abstract: In view of the poor adsorption selectivity of collectors on the surface of diaspore and kaolinite,three different types of polyacrylamide inhibitors were added to adjust the selective adsorption difference of collectors on the surface of minerals. The effect of inhibitor type on the adsorption capacity difference and interaction change of the collector propylene bisdodecylamide propyl dimethyl ammonium chloride (DAPDPAC) on the mineral surface,and the effect of the inhibitor on the flotation of the two minerals were studied. The flotation test results showed that compared with nonionic polyacrylamide (NPAM) and anionic polyacrylamide (APAM),cationic polyacrylamide (CPAM) showed a significant difference in flotation adjustment of the two minerals by the collector. When the concentration of CPAM was 80 mg/ L,the recovery rate of diaspore was significantly inhibited,while the recovery rate of kaolinite was almost unchanged. In the acidic to weakly alkaline environment,diaspore and kaolinite could be well separated by flotation. The results of infrared spectroscopy showed that the addition of inhibitor CPAM effectively hindered the adsorption of DAPDPAC on the surface of diaspore,while the adsorption on the surface of kaolinite did not change significantly. The results of adsorption capacity,Zeta potential and XPS tests showed that when the dosage of CPAM was more than 80 mg/ L,the difference of adsorption capacity of DAPDPAC on the surface of diaspore and kaolinite remained above 9. 76×10-7 mol/ g. Therefore,CPAM can effectively regulate the selective adsorption of DAPDPAC on the surface of diaspore and kaolinite,which is beneficial to strengthen the flotation separation of diaspore and kaolinite by DAPDPAC.

Key words: diaspore,kaolinite,reverse flotation,inhibitor