Microwave absorbing properties of high titanium slag

Microwave absorbing properties of high titanium slag were investigated by using microwave cavity perturbation technique. High titanium slag containing more than 90% TiO₂ was prepared by carbothermal reduction of ilmenite. The temperature rise curve of high titanium slag in microwave heating process was obtained. Crystalline compounds of high titanium slag before and after microwave irradiation were obtained and characterized by X-ray diffractometry (XRD). Effects of particle size of high titanium slag and mixtures of high titanium slag with different mass fractions of V₂O₅ on microwave absorbing properties were investigated systematically. The results show that high titanium slag has good microwave absorption property; untreated high titanium slag mainly consists of crystalline compounds of anatase and iron titanium oxide, while the microwave-irradiation treated one is mainly composed of crystalline compounds of rutile and iron titanium oxide. Synthetic anatase is transformed completely into rutile at about 1 050 °C for 20 min under microwave irradiation. High frequency shift and low amplitude of voltage make high titanium slag an ideal microwave absorbent. 180 μm of particle size and 10% mass fraction of V₂O₅ are found to be the optimum conditions for microwave absorption. Foundation item: Project(2007CB613606) supported by the Major State Basic Research and Development Program of China; Project(50734007) supported by the National Natural Science Foundation of China