Purification of H2SO4 of pickling bath contaminated by Fe(II) ions using electrodialysis process

摘要

We used in this work electrodialysis (ED) to remove the iron (II) ions of sulfuric acid pickling bath. This technique has proven very useful and effective in our study. Indeed, it allowed us to demonstrate the effect of various parameters (current density, the nature of the membrane and the concentration of Fe (II)) on the efficiency of the electrodialysis process. The results obtained show that the treatment rate increases with increasing the current density in the range 1 to 20 mA.cm~(-2). However, increasing up to 30 mA.cm~(-2) led to a clogging of the membrane, involving a substantial increase in the electrical resistance of the system. Moreover the increase in concentration of iron ions in the feed compartment to 52g.L~(-1) improves the purification rate 70.17%. The study of the influence of the membrane nature has shown that the CMX membrane more effectively than CMV and two Nafion 117 membranes. In parallel with the treatment process is also studied the possibility to refocus sulfuric acid was studied a removal mechanism iron ions and sulfates of the study define the solution for species that might exist in the system Fe -H2SO4 - H2O. It is clear from this analysis that the purification of the solution (Fe (II) -H2SO4) processing will be based on the elimination of Fe~(2+) ions and HSO_4~-. A purification mechanism of the solution based on the transfer of species through the ion exchange membranes has been proposed.