Abstract: Flotation test， adsorption test， and solution chemical calculations were used to investigate the effect of siderite and dolomite on quartz flotation in sodium oleate flotation system. The results of flotation and adsorption tests showed that the effect of siderite on quartz flotation is related to the dissolved siderite species and starch， and siderite significantly influences flotation of quartz in the presence of starch. The negative effect of dolomite on quartz flotation could be whittled by increasing the dosage of sodium oleate. The solution chemical calculations indicated that dissolved siderite species might convert the initial surface of active quartz to CaCO₃ precipitates which can be easily depressed by starch， while the dolomite dissolution is restrained by calcium ions in the solution， which might explain the difference of effects on quartz flotation between dissolved siderite species and dissolved dolomite species.

Key words: quartz, sodium oleate, siderite, dolomite, solution chemistry