Abstract: In order to promote the high-value utilization of bulk solid waste such as iron tailings,a polymer grouting material based on iron tailings was prepared by using silicon-aluminum iron tailings in northern Hebei as raw material and water glass as alkali activator. Taking the iron tailings content,alkali equivalent and water glass modulus as the influencing factors, the effects of various factors on the working and mechanical properties of the slurry were investigated by single factor test and response surface method,and the ratio was optimized by multi-objective optimization. The results show that the increase of iron tailings content reduces the fluidity and compressive strength of the slurry, but contributes to the development of the later strength of the slurry. The suitable alkaline environment has a positive synergistic effect on the growth of slurry strength. The interaction between iron tailings content and alkali equivalent has a significant effect on the fluidity and compressive strength of the slurry. When the iron tailings content is 40%,the alkali equivalent is 5. 68%,and the water glass modulus is 1. 56,the comprehensive performance of the grouting material is the best. The geopolymerization reaction of iron tailings,slag and fly ash under the action of activator produces C-S-H gel and AFt crystal. At the same time,some iron tailings particles are filled between the pores,making the overall structure more dense. 

Key words: iron tailings,alkali activator,geopolymer,grouting materials,response surface methodology,hydration mechanism