Influences of process water chemistry on reverse flotation selectivity of iron oxides
Yan Wu 1
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Kunming University of Science and Technology
Dianwen Liu   

Kunming University of Science and Technology
Publication date: 2022-07-04
It is critical for water quality in flotation as it dramatically influences the chemical/electrochemical properties of mineral surfaces and their interactions with reagents. This study aimed to identify the key elements from the recycled water sources affecting the separation efficiency in a typical industrial flotation circuit of iron oxides through a series of flotation tests, zeta potential measurement, etc. The flotation results pointed out that a concentrate with a sharp increase of 6.0% Fe recovery and 2.5% SiO2 content was obtained by using the recycled tailing water in comparison by using fresh water. While a slight uptrend in the grade of Fe but a substantial loss of near 6.5% Fe recovery occurs by using the treated sewage water instead. This could attribute to the ion distributions in these water sources, in which Ca2+, Fen+, Mg2+, or SO42- ions were determined as the key ions influencing the flotation behaviors of the iron ore. But the competitive effects of Fe3+ ions were more significant than the other metal ions. The occurrence of starch deteriorates the dilution of silicates in concentration induced by Fe3+/Fe2+ ions. It can be explained by zeta potential measurement or solution chemistry of those ions, indicating that at 8.5-9.0, the coating of the precipitates of Fe(OH)3(s) induced by iron ions alters a reverse on the zeta potentials of quartz. The presence of SO42- ions acting as a chelating agent of Fen+ ions, however, has a positive role in reducing the possibility of slime coating on silicates.