| Popis: |
This is an article in the field of ceramics and composites. In order to effectively treat and resource utilize lateritic nickel slag, this study used lateritic nickel slags as raw materials and measured the pH value of leaching solution, metal leaching concentration, material unconfined compressive strength, dry shrinkage, elastic modulus, permeability coefficient and other indexes of the cementing material formed by cement solidification, and analyzed the feasibility of using it as backfill material for construction land or highway construction engineering materials. The results show that the cementitious material is made of waste slag (dry basis) 92%, PO42.5 cement 5%, bentonite 3%, PAC 0.5% and water, the pH value of leaching solution is about 8.45, the concentration of leaching metal ions is less than 0.1 mg/L, the unconfined compressive strength is 1.47 MPa, the modulus of elasticity is 1196 MPa, the permeability coefficient is 8.77×10-7 cm/s, and the dry shrinkage resistance is good. It can be used as backfill material for construction land or highway construction engineering. The raw soil cementitious material made of 92% raw soil (dry basis), 5% PO42.5 cement, 3% bentonite, 0.02% additional CHF and 5%～8% water has better dry shrinkage resistance. It can be used as the surface layer of large volume cementitious material to resist dry shrinkage cracks caused by long-term contact with dry air, protect the waste slag cementitious material in the lower layer and ensure the overall stability of cementitious materials. The above research provides a new way for the comprehensive utilization of laterite nickel slags, and lays a theoretical foundation for the research and engineering practice of waste slag as backfill materials or highway building materials. |
