Effect of Cu2+/SO42− ions concentration on the adsorption capacity of synthetic mayenite, its application for secondary adsorption process and utilization in cement samples

Abstract

In this work, the effect of the concentration of Cu2+/SO42− ions on the primary adsorption capacity of synthetic mayenite, its thermal stability (after the first adsorption cycle), the application as a new effective secondary adsorption material, and, finally, the utilization in cement samples was examined.It was determined that mayenite samples can be applied for the removal of Cu2+/SO42− ions from the liquid medium; however, the adsorbed amount of Cu2+/SO42− ions and the efficiency of purification depend not only on the properties of the liquid medium, but also on the calcination temperature. It should be highlighted that, after the adsorption process, katoite, ettringite and partial carbonization compounds were formed. The thermal stability of the products after the adsorption processes was investigated within the 350–950 °C temperature range, and the products were later reused in the adsorption process. It was determined that the calcination (after the first adsorption process) of the products had positive influence on the adsorption capacity of Cu2+ ions and SO42− anions. After the second adsorption cycle, ettringite dominated across the entire range of products. The results of our hydration experiments showed that the above mentioned calcination product had a positive effect on the early hydration of Ordinary Portland cement samples. The obtained results were confirmed by X-ray, FT-IR, SEM/EDX, simultaneous thermal and heat release analyses.