A systematic review of mixing technology for recycling waste tailings as cemented paste backfill in mines of China

The development of industry is inseparable from the support of mining, but mining processes consume huge energy, and huge tailings emissions can make a significant impact on the environment. In the past decades, mining industry has also developed many technologies that are related to mineral energy management, of which cemented paste backfill (CPB) is one of the representative technologies. CPB has been successfully applied to mine ground control and tailings management. In the CPB technology, the mixing process is key to achieving materials with a good final quality and controlled properties. However, in the preparation process, mixed homogeneity of the CPB is hard to achieve due to fine tailings, high solid volume fraction, and high viscosity. Most of the research focused on the effect of mixing ingredients on CPB properties rather than on the preparation process of the CPB. Therefor, it is vital to improve the performance and reduce the production cost of CPB by optimizing the mixing process. This review summarizes the current studies on the mixing technology of the CPB and its application status in China. Then it compares the advantages and disadvantages of various mixing equipment and discusses the latest research findings and research hotspots in paste preparation. Finally, the challenges and development trends of mixing technology are concluded based on the relevant application cases in China for the purpose of promoting cement-based material mixing technology development.