Thermal, mechanical and ultrasonic properties of cemented tailings backfill subjected to microwave radiation

Abstract Cemented tailings backfill (CTB), which is normally prepared by mixing tailings, binder and water, is applied to fill underground mined-out areas for ground control and waste disposal. When the CTB is placed underground, it should quickly gain satisfactory strength to ensure safe and efficient mining production. However, in some high-altitude areas, such as the Qinghai-Tibet Plateau, the low temperature limits the strength development in the CTB. As a result, it is necessary to develop a method, such as microwave technique, to provide fast and effective temperature rise for the CTB. In this paper, the thermal, mechanical and ultrasonic properties of CTB subjected to microwave radiation are studied. The obtained results indicate that the microwave technology can significantly affect the temperature distribution, strength development and structural compactness of the CTB. When the same microwave energy is applied, the thermal, mechanical and ultrasonic behaviors of the CTB vary with different curing age, solid content and binder-to-tailings ratio. The current study reveals that the microwave technique can reliably improve the stability and durability of the prepared CTB structures. Therefore, this study can contribute to a further step for the practical application of the microwave technique to the CTB technology.