Ref.: MmeCa12-003

In-situ high temperature XRD and TEM study of the thermal behavior of K-birnessite obtained from Mn tailings (Carajas Mineral Province, Brazil)

Apresentador: Rosiellen Monteiro Soares

Autores (Instituição): FIGUEIRA, B.A.(UNIVERSIDADE FEDERAL DO PARÁ); Soares, R.M.(Universidade Federal do Pará); Sousa, M.D.(universidade federal do pará); Barreto, I.A.(Universidade Federal do Pará); Choque Fernandez, O.J.(Instituto Federal de Educação, Ciência e Tecnologia do Pará); da Silva, G.J.(UFPA); Reis, A.S.(UNIVERSIDADE FEDERAL DO PARÁ);

Resumo:
Birnessite is an important Mn oxide phase with a layered structure formed by MnO6 building blocks with cations and H2O molecules in the interlamellar space. Its applications range from batteries to catalysis and adsorption of inorganic and organic pollutants. The final material synthesized was characterized using analytical techniques such as SEM, TEM and in situ XRD to monitor the lamellar phase at high temperatures. The results showed that the Mn tailings were successfully converted into K-birnessite under hydrothermal conditions, with a platy-like morphology and average size of 90 nm and thermal stability above 900º C, with maintenance of the layered structure, despite intense losses of H2O molecules and interlamellar K+ ions.