Mullite raw material adopting alumina-chrome slag as main ingredient and preparation method thereof

Abstract

The invention relates to a mullite raw material adopting alumina-chrome slag as a main ingredient and a preparation method thereof. According to the technical scheme, the method comprises the steps that the alumina-chrome slag is placed into a muffle furnace, and calcination is performed under the temperature of 700-750 DEG C for 3-5 h to obtain calcined alumina-chrome slag; the calcined alumina-chrome slag, silica powder and aluminite powder are mixed on the basis that the mass ratio of the calcined alumina-chrome slag to the silica powder to the aluminite powder is 100:(16.0-16.5):(2.0-4.5) for 15-20 min, and a mixed material is obtained; the mixed material is placed into an electromagnetic induction furnace, the temperature is increased to 1,800-1,840 DEG C and kept constant for 2-3 h; then, an upper scum layer is separated out, furnace cooling is performed to the room temperature, and crushing is performed to obtain the synthesis mullite raw material adopting the alumina-chrome slag as the main ingredient. The alumina-chrome slag contains main chemical components: 80-85 wt% of Al2O3, 10-15 wt% of Cr2O3 and not larger than 1 wt% of Fe2O3. The technology is simple, the production cost is low, and no special requirement for equipment is needed; the prepared mullite raw material adopting the alumina-chrome slag as the main ingredient is high in refractoriness, good in sintering performance and high in mullite conversion rate.

Description

technical field [0001] The invention belongs to the technical field of synthesizing mullite. Specifically relates to a synthetic mullite raw material with aluminum chromium slag as the main material and a preparation method thereof. Background technique [0002] Aluminum chromium slag is the slag produced by smelting ferrochromium alloy. It uses chromite ore as the main raw material and uses metal Al powder as the reducing agent. It is a widely used and mature industrial technology to prepare ferrochrome alloy through thermite reduction reaction. Compared with ferrochromium alloy, the specific gravity of slag is small, and it floats on the alloy layer to form a slag layer, and the two are easy to separate. However, most enterprises use the discarded slag in the development of refractories after simple crushing and classification, which not only causes a waste of resources, but also causes serious environmental pollution in chromium-containing refractories. [0003] The mai...

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Problems solved by technology

Mullite is synthesized by sintering method, its grain size is small, and there are many defects such as pores, and the process of synthesizing mullite is accompanied by 7~8% volume expansion, which is not conducive to the sintering and densification of mullite; and Mullite is prepared by electromelting. Although the mullite grains grow and develop completely, the energy consumption is relatively large, which undoubtedly increases the preparation cost of mullite raw materials.