Production of High Alumina Fire Brick from Iraqi Clay


The importance of refractory materials in various industries such as lining of kilns, furnaces and the need for exploitation of raw materials which are available in Iraqi industries. So this work deal with the exploitation of Iraqi kaolin from Dewechla deposits, as a raw material in the manufacturing of high alumina fire brick.High alumina fire brick specimens (alumina content about 70%) were prepared by semi-dry pressing, then drying and burned at different temperatures 1200,1300, 1400,1500Cᵒ for 2hr soaking time and 100Cᵒ/hr firing rate. Investigations of these specimens show that, the increasing alumina content will increase the strength, the porosity of the fire products, while the hardness, apparent density, water absorption and permanent linear change will decrease. These properties affected by the firing temperature, where the formations of the mullite phase play a governed role in the behavior and properties of the final products. In addition, the results reveal that the fire brick products appear to withstand thermal shock resistance; it can be used as thermal insulator in various industries. The thermal conductivity and density behavior of products containing alumina ˃ 70% are vary as a function of porosity. Thus, the insulating property of the end product can be improved through the porosity and its distribution.