Preparation of high-performance lightweight materials based on the phosphogypsum-inorganic material system

Abstract

Phosphogypsum (PG) is a typical solid waste of the phosphorus chemical industry, The existing stock in the world has exceeded 5.6 billion tons, and its resource utilization rate is less than 30%. In order to improve the resource utilization rate of PG, this paper explores the prospect of PG and inorganic material composite systems in the large-scale absorption and utilization of PG, inorganic materials mainly include S95 slag powder(S95), fly ash (FA), Quicklime (QL) and ordinary Portland cement (OPC). The pretreatment of phosphogypsum is mainly to calcine at high temperature, the gradient of an H2O2 foaming agent affected the mechanical characteristics of a binary concrete system based on PG was explored based on the optimum mix ratio of PG and inorganic substance to formed four different binary concrete systems. The experimental results show that in the binary concrete system, when the addition amount of S95, FA, QL, and OPC was 20%, 13%, 6%, and 26%, respectively, they show significant comprehensive performance, OPC has the most significant effect. The optimum addition of H2O2 to the four binary concrete systems is 0.2%, 0.4%, 0.6%, and 0.6%, respectively. The mechanical properties of the system are less affected by the foaming agent, and found an increase in its flexural strength from 4.5 MPa to 4.75 MPa, softening coefficient from 0.88 to 0.99, and compressive strength from 16.3 MPa to 17.3 MPa. This research greatly reduces the difficulty of phosphogypsum resource treatment and provides basic theoretical support for a large amount of phosphogypsum consumption.