Damages of Refractory Bricks in Cement Rotary Kiln

Abstract

In Japan, various wastes are used in cement rotary kilns as raw materials or fuel, and their types and throughput has increased recently. More usage of wastes causes rapid wear of basic bricks. According to postmortem analysis data of used basic bricks in the burning zone and the transition zone of cement rotary kilns, causes of the brick wear were studied. In the burning zone, thermal spalling would occur during heating-up and initial operation period and/or heavy erosion would take place in service. In the transition zone, bonding strength of the heated surface-layer of the basic bricks was lowered by repetitive temperature fluctuation and the reaction with sulfur oxide. Then the deteriorated bricks were exposed to external stress and spalling takes place.
Wear mechanisms of the bricks in the burning and the transition zones of cement rotary kilns were presented and the reaction of the bricks with sulfur oxide was especially noticed.