Removal of chloride ions from acidic solution with antimony oxides

[Display omitted] •The concentration of Cl- can be reduced to 0.38g/L by Sb2O3·xH2O in acidic solution.•C-SbA can achieve low loss of Sb in the adsorption process, and the used C-SbA can be reused after being calcined at 400℃ for 2h.•Loaded adsorbent can be regenerated in the solution with pH is equal or more than 9.5, and the cycle performance of Sb2O3·xH2O is very good.•The Cl- in the regenerated solution was crystallized and precipitated in the form of NaCl without evaporation and concentration, and the purity of NaCl was >99%. After crystallization, the solution was reused in the loaded adsorbent desorption process. This study aims to investigate the removal of Cl- from acidic solution with antimony oxides. The effects of the adsorbent type, reaction time, reaction temperature, Sb/Cl mole ratio and acidity on adsorption performance and the regeneration of loaded adsorbent were systematically studied. The results shows that Sb2O3·xH2O has the highest adsorption rate (97.64%) among Sb2O3·xH2O, Sb2O5·xH2O, Sb2O4·xH2O and Sb2O3 in the solution containing 1.25mol/L H2SO4 under the condition of Sb/Cl mole ratio 3:1 and stirring for 2h at room temperature, and the concentration of Cl- in the acid solution can be reduced to 280mg/L. Then the residual Sb in the adsorbed solution can be decreased from 48.21mg/L to 16.09mg/L by C-SbA which is made by Sb2O5·xH2O. The C-SbA which has been used can be reused after calcining at 400℃ for 2h. The loaded adsorbent was completely regenerated by adding it into NaOH or Na2CO3 solution whose pH is equal or more than 9.5 according to S/L ratio 1:6g/mL and was stirred for 0.5h at room temperature. The Cl- in the regenerated solution was crystallized and precipitated in the form of NaCl without evaporation and concentration according to the common ion effect of Na+, and the purity of NaCl was more than 99%.