Novel TiO2-doped MgCr2O4 with high infrared radiation property and low Cr6+ formation for high-temperature furnaces energy-saving

MgCr 2 O 4 is a potential infrared radiation material for high-temperature furnaces energy-saving. However, poisonous Cr 6+ is easily formed in MgCr 2 O 4 -based materials during the preparation process, which is harmful to the environment. In this study, TiO 2 -doped MgCr 2 O 4 materials were prepared at 1600 ℃ by solid-phase sintering method. The effects of TiO 2 as a dopant on the infrared radiation properties of MgCr 2 O 4 and the leaching concentration of Cr 6+ were investigated, and the mechanism was discussed. Results show that the emissivity of MgCr 2 O 4 in both near-infrared and mid-infrared bands is enhanced with the increase of TiO 2 content, and the specimen MgCr 1.6 Ti 0.4 O 4.2 has the highest average emissivity in the 0.8–2.5 μm and 2.5–10.0 μm bands, which are 0.82 and 0.87, respectively. Moreover, the addition of TiO 2 significantly reduces the Cr 6+ content of MgCr 2 O 4 , with the Cr 6+ removal rate of MgCr 1.6 Ti 0.4 O 4.2 up to 84.2 %.