Study On Properties Of Lithium Slag-slag Base Composite Cementitious Material And Its Application In Curing Agent

In recent years,due to the rapid development of new energy vehicles and digital electronic products,the demand for lithium products is gradually increasing,followed by the production of lithium slag,a by-product of lithium extraction process,is also increasing.The accumulation of lithium slag not only occupies a large amount of land area,but also causes pollution to the environment.Based on this situation,the problem of lithium slag stacking can be solved if lithium slag can be "turned into treasure" and applied to building materials.In this paper,the influence of activation methods(mechanical activation,thermal activation and composite activation)on the mechanical properties of lithium slagcement cementification material is studied in depth.Through orthogonal test,the optimal activation process is as follows: grinding time 45 min,calcination temperature650℃,calcination time 90 min.The activated lithium slag was combined with mineral powder and cement in different proportions to form lithium slag-slag-cement ternary cementative material.The mechanical properties,porosity,phase composition and microscopic morphology of the lithium slag-slag cementative material were studied by universal testing machine,mercury injection meter,X-ray diffractometer and scanning electron microscope.Based on the mechanical properties of the samples and the content of lithium slag,it is concluded that the properties of K-2 and K-5 samples are better,and their compressive strength is above 42.5MPa and 32.5MPa,respectively,and the content of lithium slag is 16% and 40%,respectively.Lithium slag-slag-cement ternary cementitious material was used as curing agent to prepare copper tailings unfired bricks.The compressive strength,water absorption and softening properties of unfired brick with copper tailings containing 10%,15%,20% and 25% curing agent were studied.Based on the mechanical properties of unfired brick,the results show that the best forming process of unfired brick is 11% moisture content and 50 MPa forming pressure.Among them,the properties of the unfired bricks with 25% K-2 content and20% K-5 content and 25% K-5 content meet the requirements of the standard "Nonsintered waste Tailings Brick"(JC/T 422-2007).