Corundum-mullite castable for zinc oxide rotary kiln and preparation method of corundum-mullite castable

Abstract

The invention relates to a corundum-mullite castable for a zinc oxide rotary kiln and a preparation method of the corundum-mullite castable. According to the technical scheme, the preparation method comprises the following steps: firstly, taking 40 to 60 weight percent of porous corundum-barium aluminate particles, 10 to 20 weight percent of mullite particles, 5 to 15 weight percent of zirconium mullite fine powder, 5 to 15 weight percent of white corundum fine powder, 5 to 15 weight percent of sillimanite fine powder, 5 to 10 weight percent of silicon oxide micro powder, 1 to 5 weight percent of samarium oxide fine powder, 1 to 5 weight percent of barium sulfate fine powder, 1 to 5 weight percent of sialon fine powder and 1 to 2 weight percent of titanium silicon carbide fine powder as raw materials; and adding 0.02-0.08 wt% of a water reducing agent, 1-4wt% of calcium aluminate cement and 7-15wt% of water into the raw materials, uniformly stirring, and carrying out vibration molding, thereby obtaining the corundum-mullite castable for the zinc oxide rotary kiln. The corundum-mullite castable for the zinc oxide rotary kiln prepared by the invention has the characteristics of environmental friendliness, low heat conductivity coefficient, good wear resistance, high thermal shock resistance and excellent erosion resistance.

Description

technical field [0001] The invention belongs to the technical field of castables for zinc oxide rotary kilns. Specifically relates to a corundum-mullite castable for a zinc oxide rotary kiln and a preparation method thereof. Background technique [0002] Zinc oxide rotary kiln is an equipment for recovering zinc oxide in zinc-containing slag, which belongs to high-temperature pyrometallurgy equipment. The service conditions of the lining hot surface refractories are relatively harsh, such as high temperature in the furnace, high concentration of corrosive gases such as alkali, zinc and sulfur dioxide, and the lining hot surface refractories are also subject to airflow erosion and severe fluctuations in furnace temperature. In order to ensure the stable operation of the rotary kiln, it is required that the high temperature strength and thermal shock resistance of the lining hot surface refractory material should be good, and it should also have good wear resistance and gas p...

AI Technical Summary

Problems solved by technology

However, magnesia-alumina-chrome bricks not only have high apparent porosity, low strength and poor wear resistance, but also have poor thermal shock resistance due to high thermal expansion coefficient.

During the long-term use, it is found that the erosive gas easily penetrates into the interior of the magnesia-alumina-chrome brick along the brick joints and pores, changing the structure of the refractory material, coupled with the effect of air flow erosion and thermal stress, part of the refractory material is separated from the brick body, forming peeling, resulting in brick failure. serious damage to the body

In addition, the high thermal conductivity of magnesia-aluminum-chrome bricks leads to serious heat dissipation in the kiln body; trivalent chromium will be converted into carcinogenic hexavalent chromium ions during use, which seriously threatens the health of humans and animals

"A aluminum-chromium-zirconium-silicon composite brick for the reaction zone of a zinc oxide rotary kiln and its preparation method" (CN112299826A) patented technology, using plate-shaped corundum, fused chromium-aluminum spinel, silicon carbide, zirconia and alumina superfine powder Al-Cr-Zr-Zr-Si composite bricks for zinc oxide rotary kiln are produced by mixing and pressing molding as raw materials. The main disadvantage of this technology is that the fused chromium-aluminum spinel used will pose a greater threat to human health and safety. Moreover, the brick uses dense plate-shaped corundum as the main raw material, which has poor thermal shock resistance and high thermal conductivity. In addition, it is difficult to densify the brick body, and its resistance to gas phase erosion medium permeability is still poor.