大掺量磷石膏基充填材料的制备及性能研究OA

Phosphogypsum is an industrial by-product produced in the production process of wet-process phosphoric acid.Its large stockpiling not only occupies valuable land resources,but also has environmental risks.The high-content phosphogypsum-based filling material was prepared by using carbide slag as alkaline activator and slag-based cement powder.The rheological properties,mechanical properties,durability and leaching toxicity were tested,and the field filling experiment was carried out.The results show that the optimum ratio of high-content phosphogypsum-based filling material is 10%of cement powder,3%of carbide slag and 87%of phosphogypsum.The fluidity of filling slurry prepared under this ratio is 23.2 cm,and the 28 d compressive strength is 4.1 MPa.The leaching indexes of fluoride and heavy metals meet the requirements of the specification.In the field test,the roof contact rate of the filling body is more than 85%,the compressive strength meets the requirements of use,the environmental pollution is controllable,and the comprehensive filling cost is 56.18%lower than that of the traditional cement tailings filling process.The research results can provide technical reference for the large-scale consumption of phosphogypsum.