赤泥基地聚物充填体抗压强度与离子浸出行为研究OA

To investigate the strength characteristics of slag-and red mud-based geopolymer backfill and its ion slow-release behavior in groundwater environments,unconfined compressive strength(UCS)tests were conducted to characterize its mechanical properties.Meanwhile,long-term underground leaching environ-ments were simulated to analyze its chemical dissolution process and ion release patterns.The results show that the 28-day UCS of the specimens exhibits a nonlinear variation trend of first increasing and then decrea-sing with the rise of water-to-solid ratio,reaching a local peak of 2.55 MPa at a water-to-solid ratio of 0.38.In contrast,the UCS shows a monotonic increasing trend with the increase of calcium carbide slag(CCS)dosage,and the strength rises to 2.71 MPa when the CCS dosage reaches 20%by mass.Various multi-di-mensional water quality indicators of the static leachate,including pH,COD,TOC,TDS,UV275 and EC,all present violent fluctuations in the initial stage.With the elapse of time,the active components in the sys-tem gradually reach a dynamic dissolution-precipitation equilibrium,and the skeletal structure of the back-fill becomes stable.However,microscopic tests indicate that structural loosening and fracture have occurred inside the specimens,and the polymeric products show obvious deterioration and degradation,which reflects the adverse effect of long-term leaching on the durability of the material.The research results not only reveal the coupling mechanism of slag-and red mud-based geopolymer backfill in terms of mechanical properties and environmental response,but also provide scientific basis and technical support for the application of such materials to engineering fields,such as ecological environment protection and groundwater preservation.