Effects of CO2 on the zeta potential of hematite

►Sparging hematite slurry with CO2 caused a magnitude reduction in zeta potential vs. pH curve. ►Double layer compress effects do not fully account for zeta potential changes. ►Literature review points to formation of hematite/carbonate complexes. ►Zeta potential of hematite sparged with CO2 similar to siderite. ►Phenomenon observed in both laboratory and plant samples.