Silicate sorption on ankerite from a standard silicate solution

Abstract

The effect of geological deposition conditions on the durability of glass used for radioactive waste disposal is investigated in this study. Iron mineral compositions or other near-field parameters within the final disposal repository may influence the durability of highly radioactive glass. The experimental study of silicate sorption by natural Ankerite is presented in this article. A preliminary analysis was conducted to determine the difference in silicon concentrations in standard solution in the presence of natural Ankerite utilizing the graphite furnace atomic absorption method. All of the standard solutions were diluted from a saturated silicate stock solution. Natural Ankerite mineral samples collected in Rudabánya, Hungary, demonstrated heavy (H4 SiO4) sorption at their interface. Batch experiments with specific masses of natural Ankerite and silicate solution were conducted to demonstrate a better understanding of silicate reduction in solution due to Ankerite's sorption mechanism, demonstrating that Ankerite has the capacity to uptake silicate. The desorption of adsorbed silicate was investigated, and it was discovered that only very minimal quantities of silicate were returned to the solution, resulting in tiny reversed concentrations of silicate, perhaps indicating chemisorption. The experiment reported the highest averaged adsorption of silicate and the lowest averaged desorption capacities of 98.9 % and 3.7 percent respectively at a higher Ankerite Surface Area to Volume of solution, (SA/V) = 3600 m−1, however the lowest averaged adsorption and the highest averaged desorption capacities of 85.8 % and 8.9 % respectively at a lower SA/V = 480 m−1.