Removal of Co2+ and Ni2+ Ions from Aqueous Solutions by Low Cost Synthetics Na-4-mica

A high charged density sodium fluorophlogopite mica Na-4-mica, ideal chemical structure Na4Si4Al4Mg6O20F4.xH2O, was prepared by a simple and economic method using kaolinite as a source for SiO2, Al2O3 and MgO. The prepared mica was characterized by using XRD, DSC and SEM. Na-4-mica was used for removal of Co2+ and Ni+2 ions from aqueous solutions using a stepwise remediation method. The factors affecting the removal efficiency such as pH change during the exchange reaction, particle size of Na-4-mica, initial metal concentration were investigated. The results showed the removal efficiency increased by decreasing the particle size of the mica and initial concentration of the heavy metal in the solution. Na-4 mica showed removal efficiency for Ni2+ ions higher than that for Co2+ ions. This related to the difference in the hydrated ions radii between Co2+ and Ni2+ ions.