A Study on the Development of Refractories for Carbon Black Reactor

Abstract

High alumina refractories are manufactured with high quality raw materials and normally possess good hot properties and can be lined in operation zones with critical conditions. However, certain application areas require very high specifications. An example is the carbon black reactor which operates beyond 2000°C. Here, conventional high alumina refractories do not give good performance and life. In the present study, an attempt has been made to study the development of refractories suitable for use in carbon black reactor. Zirconia is added to high alumina refractories to improve its thermo mechanical properties and spalling resistance. Transformation toughening due to tetragonal to monoclinic phase change in zirconia is utilized for the improvement of properties. Zirconia can be obtained from many sources. The raw materials selected have an important bearing on the properties of the final product. Three different sources of zirconia were used to optimize zirconia. This was followed by optimization of reactive alumina. Reactive alumina has very fine particle size which helps to achieve better sintering and reduces porosity. Hot properties were further improved by the addition of chrome oxide. Physical, thermal and thermo – mechanical properties, critical to operating conditions in the carbon black reactor, were studied and reported in this thesis.