Effect of aluminum-chromium slag addition amount on the performance of recycled castables

In order to develop the monolithic refractory materials for the lining of Ausmelt furnaces and meanwhile achieve the recycling of aluminum-chromium slag, a waste slag of the ferroalloy smelting industry, fused magnesia was used as the main raw material. A certain amount of treated aluminum-chromium waste slag was added to replace magnesia-chrome raw materials. These were thoroughly mixed with alumina micropowder and aluminate cement binder in a mixer, then poured into molds. After curing and firing, magnesia-alumina-chromium castables were produced. The experimental results show that when the addition amount (w) of aluminum chrome slag is 15%, the recycled castable possesses a comparatively dense structure, good strength at room temperature, resistance to thermal shock, and resistance to slag corrosion, making it an ideal addition amount. Through comparison with the performance of the currently used magnesia-chrome bricks in the Ausmelt furnace, the recycled castable has the basic conditions to replace the refractory lining materials of the Ausmelt furnace.