The green process to recover magnesium chloride from the residue solution of a potassium chloride production plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The residue solution contains magnesium chloride above 25 wt-%, potassiumchloride and sodium chloride together below 5 wt-% and a few other ions such as Br−, SO42− and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evaporation-cooling crystallization procedure to produce magnesium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

CdSe nanocrystals (NCs) have great application prospects in various fields due to their novel properties. Some high-cost and toxic materials such as tri-n-octylphosphine oxide (TOPO) are used in the popular method to synthesize CdSe NCs. Based on this, a new low-cost, environmentfriendly and safe solvent was introduced in the synthesis of CdSe NCs in this paper. The prepared CdSe NCs were characterized by ultraviolet-visible spectra (UV-Vis), photoluminescence (PL), transmission electron micrograph (TEM), energy disperse X-ray spectra (EDX) and X-ray diffraction (XRD). The CdSe NCs obtained which show a good PL property are monodisperse, size-tunable and of high crystallinity. It indicates that the new solvent A is a good substitute for the solvent used in the classic route and achieves a greener synthesis of CdSe NCs.

The solubilities of dexibuprofen in five solvents including methanol, n-butyl alcohol, isobutyl alcohol, n-amyl alcohol, and n-octyl alcohol were measured in the temperature range 263.15–293.15 K under atmospheric pressure. The results indicate that the solubilities of dexibuprofen in the selected solvents increase with temperature. The experimental data were correlated by the modified Apelblat model which fit well with the experimental data. The dissolution enthalpy and entropy of both rac-ibuprofen and dexibuprofen were predicted. Moreover, the solubility data of both of them were correlated using two local composition models: NRTL 1 and UNIQUAC. It is indicated that for dexibuprofen, the NRTL 1 model can provide more accurate estimations of the solubility in the solvents of methanol, ethanol and n-propyl alcohol, while both NRTL 1 and UNIQUAC models can provide good estimations of the solubility in other solvents. For the rac-ibuprofen, the UNIQUAC model performs better to estimate the solubility in all the solvents.Highlights► We measured the solubility data and correlated them by the modified Apelblat model. ► The dissolution enthalpy and entropy of both rac-ibuprofen and dexibuprofen were predicted. ► The solubility data were correlated using NRTL 1 and UNIQUAC model. ► The ΔHd, ΔSd and ΔGd values were estimated and analyzed. ► We made the distinctions between the models for the (S)-enantiomer and the racemate.