Effect of thermal treatment time on structure and properties of infrared radiation coating prepared by copper slag
Copper slag,as a solid waste generated during the copper smelting process,is often stacked,occupying land resources and polluting the environment.Its resource utilization is increasingly receiving widespread attention in China and overseas.To solve this problem,the infrared radiation coating was pre-pared at 1 200 ℃ with copper slag as the main raw material,terpineol as the film forming agent,ethyl cellu-lose as the thickening agent,and high alumina bricks as the substrate material of the infrared radiation coating.Effects of the heat treatment time(0.5,2,4,and 8 h)on the microstructure and emissivity at room temperature and 400 ℃ were studied.The results show that the coating is well combined with the high alu-mina brick substrate,with heat treatment time prolonging,the coating gradually becomes dense;after heat treatment at 1 200 ℃ for 8 h,the near-infrared(0.8-2.5 μm)emissivity of the coating reaches the maxi-mum(0.862);after heat treatment for 4 h,the emissivity increases and reaches the maximum(0.928)after heat treatment in the mid-infrared(2.5-25 μm)wave range;after heat treatment for different times,the emissivity of the coating fired at 400 ℃ in 1-22 μm wave range increases continually and is higher than 0.93.Combined with practical applications,the optimal heat treatment time is 4 h.