Texto completo de evento
Reaction behavior of magnesium orthotitanate and calcium titanate with compounds of portland cement and their use in a chrome-free refractory
Autor
FERREIRA, LEONARDO C.
RODRIGUES, JOSE de A.
BERNARDI, LAURO T.
BALDO, JOAO B.
BRESSIANI, JOSE C.
PROCEEDINGS OF UNIFIED INTERNATIONAL TECHNICAL CONFERENCE ON REFRACTORIES; BIENNIAL WORLDWIDE CONGRESS, 10th
Resumen
In this work magnesium orthotitanate (Mg2TiO4)
and calcium titanate (CaTiO3) were submitted
individually to a reaction with CaO, Ca2SiO4, Ca3SiO5,
Ca3Al2O6 and Ca4Al2Fe2O10 in an electric furnace at
1450??C for 2.5 hours. The powder X-ray diffraction
analysis revealed the formation of calcium titanate
during the reaction of magnesium orthotitanate with
most of the Portland cement phases. By other hand,
calcium titanate was not affected when in contact with
Portland cement phases. These results opened a great
possibility in exploring both phases in a new chromefree
refractory. In a second step of this research, a
magnesia-magnesium orthotitanate-calcium titanate
refractory brick was produced and compared with a
standard magnesia-spinel refractory brick. Both
formulations were evaluated in thermal spalling
resistance test, apparent porosity, bulk density, true
specific gravity, water absorption, total porosity,
chemical analysis, elastic modulus, thermal expansion
coefficient and coating adherence test associated with
scanning electronic microscopy. Refractories of
magnesia-magnesium orthotitanate-calcium titanate
system presented excellent coat adherence result
maintaining the same level of thermal spalling
resistance when compared with a standard magnesiaspinel
refractory.