Grinding Characteristics and Gelling Activity of Siliceous Iron Ore Tailings Under Different Activation Modes

Mechanical activation is a commonly used method to improve the activity of tailings，and adding chemical activators to the grinding system is a more effective method. Five types of activators were used to compare and analyze the grinding characteristics and early gelation activity of siliceous iron ore tailings（IOTs）using single and composite methods. Iron ore tailings powder was prepared by mechanical activation and mechanochemical activation，and the grinding characteristics of IOTs after grinding were measured，including specific surface area，particle size distribution（PSD），and gelation activity at 3，7，28 d. The hydration products were analyzed by using XRD and SEM. The conclusion shows that the addition of various activators can increase the specific surface area of IOTs within the same grinding time，and the mechanical chemical activation with the addition of composite activators at 90 minutes of grinding can increase by up to 30. 43% compared with mechanical activation. The addition of activators improves the grinding efficiency of IOTs，resulting in a narrower PSD range. The strength increase of cementitious system in the early stage of hydration is mainly due to the fact that activator can promote the formation of ettringite，while the strength increase in the later stage is due to the improvement of tailings activity. This study is of great significance for the efficient utilization of siliceous iron ore tailings. © 2024 Northeast University. All rights reserved.