Effect of Iron(III) ions on rutile flotation: Surface properties and adsorption mechanism

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2024-09, Vol.697, p.134343, Article 134343
• Main Authors: Zhang, Xinyu, Ren, Liuyi, Bao, Shenxu, Zhang, Yimin
• Format: Article
• Language: English
• Subjects: Activation mechanism; adsorption; Benzohydroxamic acid; contact angle; hydrophobicity; iron; Iron ions; Rutile flotation; slurries; X-ray photoelectron spectroscopy; zeta potential
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2024.134343

Various studies have shown that the presence of metal ions in the slurry can significantly impact flotation. However, it was still uncertain how iron, a typical metal ion, affected rutile flotation. Micro-flotation experiments, x-ray photoelectron spectroscopy, icp-oes, solution chemistry calculation, zeta potential and contact angle test were used to explore the effect of iron ions on the surface properties and floatability of rutile in this investigation. Micro-flotation results showed that iron ions not only substantially increased the rutile flotation recovery from 42.27 % to 75.69 % at pH = 4, but also converted the optimal pH of flotation from a point (pH = 4) to a platform (pH = 4–8). Solution chemistry calculations indicated that iron ions could form complexes with hydroxyl to produce FeOH2+, which reacted with benzohydroxamic acid (BHA) to create [Fe(C7H6NO2)2]+ at pH=4–7. The analysis conducted through X-ray photoelectron spectroscopy, coupled with the results obtained from contact angle measurements, revealed that the complex [Fe(C7H6NO2)2]+ had the capability to engage with Ti-OH groups, improving the hydrophobicity of rutile surface. Zeta potential analysis results further illustrated that Fe3+/BHA complexes reinforce the adsorption of BHA and iron ions onto rutile surface by the formation of [Fe(C7H6NO2)2]+. In addition, the O1s peak fitting results and ICP-OES analysis results proved that at the same pH, 60 mg/L was the optimal concentration for iron ion activation, which may be limited by Saturated adsorption capacity of [Fe(C7H6NO2)2]+. [Display omitted] •Iron ions can efficiently activate rutile in the pH=4–7 range.•The influence mechanism of Fe3+ on rutile surface varies with pH.•[Fe(C7H6NO2)2]+ is the effective component activated group.•Iron ions in slurry would help us save pH regulators.•It provided scientific direction for rutile and gangue separation.