Composites of sintered mullite reinforced corundum granules and method for its preparation

A method for preparing a composite of sintered mullite reinforced corundum granules comprising the following steps:

• a) grinding raw materials comprising at least one clay and at least one alumina source, to obtain ground raw materials having particle size less than 45 microns;
• b) admixing the ground raw materials to obtain an admixture;
• c) granulating the admixture in the presence of at least one binder and at least one fluxing agent to obtain granulated pellet;
• and
• d) sintering the granulated pellet in a temperature range of 1300° C. to 1600° C. to obtain the composite of sintered mullite reinforced corundum granules,
• wherein the binder is at least one selected from a group of binders consisting of bentonite, starch and polyvinyl alcohol;
• wherein the fluxing agent is selected from a group of fluxing agents consisting of potash feldspar and iron ore slime;
• wherein the mullite and the corundum in the composite have interlocking microstructure and said composite consists of 6 wt. % to 80 wt. % of mullite and 10 wt. % to 90 wt. % of corundum;
• and
• wherein said composite has a compression resistance of less than 10% and an acid solubility of less than 7%.