Partitioning of perrhenate anion by aqueous two-phase systems using design of experiments methodology

Sustainable Extraction and Separation of Rhenium and Molybdenum from Model Copper Mining Effluents Using a Polymeric Aqueous Two-Phase System

“…The ATPS phase diagram formed by CuSO 4 -PEG 4000-H 2 O, taken by Claros et al and presented in Figure S1, was used as the starting point for metal partition tests. The effect of pH, temperature, and PEG 4000 and CuSO 4 concentrations on the partition of the ReO 4 – anion was previously reported . In light of these results, the composition of the ATPS CuSO 4 -polymer-H 2 O was kept constant at 13 wt.%-13.7 wt.%-73.3 wt.% (total system mass of 20 g) at the conditions of T = 35 °C and pH 2 for all extraction tests.…”

“…The partition of MoO 4 2– in ATPS composed of the nonionic surfactant Triton-100 and (NH 4 ) 2 SO 4 is strongly dependent on the pH of the aqueous solution due to the change of molybdate speciation and the formation of species with variable charge densities . Previously reported results on the mechanism of ATPS formation with CuSO 4 in the presence of MoO 4 2– and ReO 4 – , respectively, as a function of pH and temperature serve as the basis for this work. , In the ATPS composed of CuSO 4 -PEG 4000-H 2 O, a maximal molybdenum extraction of 93% was achieved in the pH range 1.5–2.5 at T = 35 °C . In contrast, temperature and pH did not have a significant effect on rhenium partitioning, and optimal rhenium extraction was obtained by increasing the PEG 4000 and CuSO 4 concentration, yielding a final ATPS composition of 13.7 wt.% PEG 4000 and 13 wt.% CuSO 4 …”

“…, respectively, as a function of pH and temperature serve as the basis for this work. 16,17 In the ATPS composed of CuSO 4 -PEG 4000-H 2 O, a maximal molybdenum extraction of 93% was achieved in the pH range 1.5−2.5 at T = 35 °C. 17 In contrast, temperature and pH did not have a significant effect on rhenium partitioning, and optimal rhenium extraction was obtained by increasing the PEG 4000 and CuSO 4 concentration, yielding a final ATPS composition of 13.7 wt.% PEG 4000 and 13 wt.% CuSO 4 .…”

“…17 In contrast, temperature and pH did not have a significant effect on rhenium partitioning, and optimal rhenium extraction was obtained by increasing the PEG 4000 and CuSO 4 concentration, yielding a final ATPS composition of 13.7 wt.% PEG 4000 and 13 wt.% CuSO 4 . 16 In the present study, the ability of PEG and polypropylene glycol (PPG) in CuSO 4 solutions to extract polyoxomolybdates and ReO 4 − is assessed, and a simple and efficient method for the separation of rhenium from molybdenum is proposed. First, the partition behavior for rhenium and molybdenum as well as their mutual selectivity was determined as a function of salt additive addition, molecular weight and nature of the polymer.…”

“…The effect of pH, temperature, and PEG 4000 and CuSO 4 concentrations on the partition of the ReO 4 − anion was previously reported. 16 In light of these results, the composition of the ATPS CuSO To further complement this, the effect of strong electrolytes as additives as well as the hydrophobicity of the polymer-rich phase on the distribution and selectivity of Mo and Re extraction was studied. The additives used were the chloride salts LiCl, NaCl, and KCl.…”