Using Iraqi materials to produce lining refractories with international standards
In this study dense high alumina refractories were manufactured according to DIN51053 standards and characterizations (physical, mechanical, and thermal) of fired specimens were investigated. The mixtures of specimens were prepared from different weight percentages of (kaolinite, bauxite with additives of alumina to all mixture ratio). The aims of this study was to benefit of local raw materials to produced high alumina refractory characterized by low porosity, in addition to manufacture thermal insulation to use as lining in different industrial furnaces, and enhance the thermal insulation, thermal stability, and mechanical properties of high alumina refractory by adding alumina. From the results it have been obtained high alumina refractory with high compressive strength, high thermal stability, and thermal insulation also have characterized by low porosities and high bulk density.
Silica-Alumina Refractory Synthesis based on Moroccan Granitic Geo-Materials
Andalusite rich schist until now has not been utilized to produce refractory. In this work, refractory materials were elaborated from alumina-silica geomaterials related to granitoids and their direct surrounding rocks (kaolin clay and andalusite riche schist). Characterization evolution on heating was investigated in a composition (80% kaolinitic clay, 20% andalusite rich schist). The evolution of mullite was examined by SEM (scanning electron microscopy) and XRD (X-ray diffraction). The thermal shock test showed that the refractory sample has a good thermal shock resistance.
Sintering and Mechanical Properties of Stoichiometric Mullite
Stoichiometric mullite powder (3Al2O3·2SiO2) prepared by spray pyrolysis and sintered at 1650°C attained 95% of theoretical density. The flexural strength was 360 MPa at room temperature and decreased slightly at 1400°C. A fairly high KIc value (2.8 MN/m3/2) was obtained. These mechanical properties can be attributed to the highly homogeneous stoichiometric composition of the raw powder.