Microwave Roasting of Stainless Steel Dust for Preparation of Black Ceramic Pigments: Effects of Microwave Power and Dwell Time
摘要
To mitigate the hazards associated with stainless steel dust and achieve the circular utilization of metal resources, black ceramic pigments were prepared using microwave-assisted roasting. Meanwhile, the effects of microwave power and dwell time on the phase composition, grain size, absorbance, and chromaticity of black ceramic pigments were investigated. The results show that as the microwave power increases from 2000 W to 4000 W, the L*, a* and b* values change from 33.6, 0.2, 0.2 to 33.7, 0.2, 0.3, and the grain size increases from 119.3938 nm to 218.5077 nm, whereas the absorbance of black pigments does not change much. When the dwell time is increased from 5 min to 40 min, the L*, a*, and b* values decrease from 33.8, 0.8, 0.3 to 33.8, 0.1, 0, respectively, and the grain size increases from 49.5193 nm to 121.6260 nm. Meanwhile, as the dwell time is extended, the absorbance of black ceramic pigments gradually increases. With a microwave power of 2000 W and a dwell time of 40 min, the L*, a*, and b* values of prepared pigments are 33.8, 0.1, and 0, respectively, with a forbidden band width of 0.61 eV and a visible range absorbance of > 94%.