Corrosion study of glaze-ceramics doped cement-kiln-dust soaked in concentrated HCI

Abstract

NEW glaze-ceramics formulated from industrial waste have been ....... prepared. The method consists of introducing cement-kiln-dust (CKD) in the industrial glaze-ceramics with various ratios (10-50%) together with the addition of 10gm boric acid. The chemical durability of the prepared composite cement-dust-glaze-ceramics (CDGC) is investigated using high concentrations of (2,5 & 8N) HCl acid solutions. CDGC are vitrified by melting for four hours at 1400oC ± 250oC depending on the amount of CKD introduced. Specifically, the experimental results indicate that the introduction of CKD in industrial glaze decreases durability. At high HCl concentrations, the durabilities of the prepared glaze-ceramics are observed to decrease with increasing the percentage of (CKD) until certain limit and almost constancy. The corrosion results are explained according to the ion exchange mechanism and formation or dissociation of the modified depleted layer. Some hollow and jogged areas are observed by SEM which might be interpreted as evidence of local corrosion phenomena. In addition, the pH values of the leachant solutions are measured. The comparison of hardness for the optimum glaze-ceramic and glaze-ceramic derivatives prepared in this study indicates a degradation % in their chemical and physical properties depending on the amount% of CKD introduced. It is observed that the degradation not only depends on the amount of CKD introduced, but also on the strength of the leaching HCl acid solution. Also, the results show that, the prepared glazes have a surface hardness values ranged from 5.5 to 2.5 in the Mohs scale.