Zeta Potential, Particle Size Distribution and Separation Efficiency Data of SiO2 and ZnO Particles during Magnetic Seeded Filtration Experiments with SiO2-MAG

General Information

1. SiO2: Material: Quartz, Manufacturer: Quarzwerke GmbH, Product Name: SF800
2. ZnO: Material: ZnO, Manufacturer: Quarzwerke GmbH, Product Name: Silatherm
3. SiO2-MAG: Material: SiO2 / Fe3O4 composite, Manufacturer: Microparticles GmbH, Product Name: SiO2-MAG-AR1062

Particle Size Distribution

For SiO2-MAG the distribution was measured with an analytical disc centrifuge (CPS Instruments), while ZnO and SiO2 were measured by laser diffraction (Helos, Sympatec).

Zeta Potential

All zeta potentials were measured at constant ionic strength I = 0.1M and constant volumetric particle concentration cv = 3.75e−3 vol-%.

Magnetic Seeded Filtration Experiments

Two individual studies (A and B) were performed. A mono-disperse silica-magnetite composite (SiO2-MAG) was used as magnetic seed material, while the non-magnetic particle system was varied between a poly-disperse SiO2 and poly-disperse ZnO powder. Stock suspensions of the dry particle systems were prepared by sonification with the Digital Sonifier 450 fromBranson Ultrasonics Co. (conditioning). A sample of the stock suspension P_0 was taken and its actual concentration determined, taking deviations in preparation into account. Subsequently, the respective volumes of the stock suspensions to achieve the desired volume concentrations c_v were transferred into a snap-on lid vial. The suspension parameters ionic strength I and pH were adjusted by addition of 2M NaCl solution and 0.5M HCl or NaOH solution respectively. Finally, the experimental volume was filled to V=3mL with ultrapure water. The suspension was agitated for the agglomeration time t_A in the laboratory shaker Vortex Genius 3 from IKA GmbH. After agglomeration, a ferromagnetic separation matrix was immersed in the suspension and the vial was positioned next to a permanent magnet. Magnetic separation was performed for t_S=2min. A representative sample P_E was taken from the non-separated suspension and sonified again in order achieve comparable levels of dispersity. Samples P_0 and P_E were analyzed via UV-VIS spectroscopy and the volume concentrations were determined through previously performed, substance- and system-specific calibrations. Separation success is quantified via the separation efficiency of the non-magnetic component defined as A_NM = 1 - (c_v,NM,E / c_v,NM,0). All experiments were measured in triplicate and the resulting standard deviation of the separation efficiency is also supplied.

Note

For more information on magnetic seeded filtration refer to publications by Rhein et al.