The interaction among multiple charged particles induced by cations and direct force measurements by AFM

Enhanced removal of scaling cations from oilfield produced water by carrier mineral floatation

This work reports a novel carrier flotation protocol for removing scaling cations from an oilfield produced water source which significantly reduces the collector consumption by employing natural minerals such as quartz, montmorillonite and talcum as the scaling cations carriers. The scaling cations uptake onto all carrier minerals exhibited homogeneous and monolayer adsorption, which was mainly dominated by physisorption. After adding oleate collector, the scaling cations removal rate was further enhanced, which was attributed to its high affinity with the scaling cations. Notably, the talcum flotation process simultaneously offered a high scaling cations removal rate (76.1%) and mineral recovery rate (98.3%), which achieved a sediment yield reduction of 72.2%. By summarizing the characterization results, the scaling cations removal mechanisms were also proposed. Moreover, high regeneration efficiencies (86.1% and 84.8% for quartz and talcum regeneration within three cycles) were achieved by the proposed regeneration protocol. This carrier flotation protocol with its low collector consumption offered technical promise for scaling cations removal from oilfield produced water.

Effect of Ferric Ions on Sulfidization Flotation of Oxidize Digenite Fine Particles and Their Significance

Digenite fine particles are easily oxidized and ferric ions (Fe3+) commonly exist in the flotation pulp of digenite. This study investigated the effect of Fe3+ on the sulfidization flotation of oxidized digenite fine particles using sodium butyl xanthate (SBX) as a collector. The results of microflotation experiments show that the flotation rate and recovery of oxidized digenite fine particles can be improved by adding Na2S and SBX, whereas the existence of large amounts of Fe3+ is not beneficial for the sulfidization flotation of digenite. The results of Fe3+ adsorption, zeta potential, and contact angle measurements indicate that Fe3+ can be adsorbed on the digenite surface mainly in the form of Fe(OH)3, which hinders the adsorption of SBX and significantly reduces the surface hydrophobicity of digenite. X-ray photoelectron spectroscopy analysis further suggests that the poor surface hydrophobicity of digenite in the presence of Fe3+ is due to the production of large amounts of hydrophilic iron and copper oxides/hydroxides on the surface. Furthermore, optical microscopy analysis shows that these hydrophilic species effectively disperse digenite fine particles in the pulp, which eventually leads to the poor floatability of digenite. Therefore, it is necessary to reduce the amount of Fe3+ present in the pulp and adsorbed on digenite surface before sulfidization to realize effective separation of oxidized digenite fine particles and iron sulfide minerals.