ANA FLÁVIA BARCELOS ANDRADE, SONIA DENISE FERREIRA ROCHA
CAROLINA MARIA FERREIRA DOS SANTOS, The effect of caustic magnesia natural impurities on magnesium oxide hydroxylation(2017)SDRP Journal Of Nanotechnology & Material Science 2(1)
This paper aims to evaluate the kinetics of hydroxylation for two distinct magnesias regarding their purity from Brazilian mineral sources: A – 92.44wt% and B – 98.20wt% of MgO. The magnesias were characterized and hydroxylated in a CSTR (1,0L) under: 80°C, stirring rate of 950rpm and 30%w/w of solids, in triplicate. The results showed that the presence of natural impurities in caustic magnesia hindered the advance of the reaction, but not at the beginning, when the hydroxylation was similar for both samples, what is associated with the similar values of their surface area. The reaction stabilization was observed after two hours for both samples: Sample A – 35.15%; Sample B – 46.43%. The natural impurities of caustic magnesia influenced the development of hydroxylation after 30 minutes, causing a retardant effect probably due to their behavior as a physical-chemical barrier, hindering the ions diffusion though the solid matrix.