Geopolymer synthesis by utilizing lead or zinc smelting slag and its tailing as raw materials

In order to realize the recycling of the secondary resources,the investigation of geopolymer synthesis was presented utilizing lead or zinc smelting slag and its tailing as the main Si-Al source materials.Firstly,the smelting slag and its tailing was pre-grinded,so as to enhance its reactivity.Then the pre-grinded smelting slag and tailings blended with the compound activators composed of sodium silicate and desulfurized gypsum was further grinded.Geopolymer samples were prepared by compressed-casting technology.As the results showed,the highest 3-day,7-day and 28-day compressive strength of geopolymer samples were 24.67 MPa,27.69 MPa and 32.81 MPa respectively when the dosage of sodium silicate was about 14wt%and the desulfurized gypsum was about 8wt%.SEM,XRD and FT-IR analysis of samples indicated that the geopolymer with dense microstructure composed of homogenous gel and acicular AFt crystal was obtained using lead or zinc smelting slag and tailing as raw materials.The different phases were closely combined in the geopolymer structure and the strength was found to be enhanced.