Aqueous Biphase Extraction for Processing of Fine Coal

The opposite effect of temperature on polyethylene glycol-based aqueous biphasic systems versus aqueous biphasic extraction chromatographic resins

“…The temperature dependant thermodynamic parameters can be obtained by fitting the temperature dependant data to the quadratic equation below (Eq. (8)) to obtain the parameters a, b, and c.…”

“…For this reason, we also evaluated the thermodynamic quantities by fitting the experimental data to Eq. (8) in order to derive the temperature dependent thermodynamic parameters. Thus, in this case not only are H • and S • temperature dependent but the equation also allows us to calculate the change in heat capacity using Eqs.…”

“…The driving force behind separation in a polymer-salt ABS is not completely understood, although phase separation may be due to water structuring and the partial dehydration of the polymer chain within the two phases [1,2,4]. Recently, a wide range of applications of the polymer-salt ABS in the separation of organic molecules, metal ions, radiochemicals, and the recovery of nanoparticulate matter and minerals have been demonstrated [5][6][7][8][9][10][11][12][13]. ABS may be thought of as relatively benign separation media since they are made of water and rather innocuous polymers such as PEG.…”

Partitioning behavior of silica in the Triton X-100/dextran/water aqueous biphasic system

“…The work in our laboratory seeks to investigate the feasibility of employing aqueous biphase extraction as a new separation technology for ultrafine inorganic particle processing [25][26][27]. As in conventional oil/water liquid-liquid extraction [28][29][30], the basic principle behind the selective partitioning of inorganic particles in aqueous biphase systems is the physicochemical interaction between the solid surface and the liquid solution.…”

“…In contrast, a hydrophobic particle, e.g., graphite, will be concentrated in the top phase [11]. It has also been found that pH adjustment can be effective in controlling the partitioning behavior of metal sulfide particles, e.g., pyrite (FeS 2 ), since their surfaces are oxidized in aqueous solution to form different products whose relative concentrations are determined by the solution pH [25,26]. Below pH 5, pyrite particles transfer into the top polymerrich phase; under these relatively acidic conditions, the surface reacts to form a hydrophobic metal-depleted product (Fe 1−x S 2 ).…”