摘要：
In order to solve the problem of bulk solid waste accumulation with the improved utilization, sintered ceramsite were prepared in this study using three brand new bulk solid wastes of the coal-fired fly ash (FA), steel slag (SS) and gold tailings (GT), with corn straw (CS) and SiC as expansion agents. The effects of the FA, SS and GT dosage as well as the different types of expansion agents on the surface morphology and physical properties of the sintered ceramsite were investigated in detail. Additionally, the sintering conditions were optimized by taking the ceramsite doped with SiC as an example. Meanwhile, the micro-morphology and crystalline phase composition of the ceramsite were analyzed by X-ray diffractometer (XRD) and scanning electron microscopy coupled with energy dispersive spectrometer (SEM-EDS). The results showed that the effect of the expansion agent was mainly in changing the size of pores, which thus affected the pore structure. However, there was no significant effect on the type of crystalline phase. Under the optimal conditions of the mass ratio of FA:SS:GT of 5:5:8, sintering temperature of 1170 oC, and sintering duration of 10 min, the prepared ceramsite showed the physical properties of the apparent density of 1552.3-1862.8 kg/m3, bulk density of 767.3-917.8 kg/m3, 24 h water absorption of 0.22-0.81%, and the compressive strength of 7.6-15.6 MPa. At the same time, the prepared ceramsite showed good fixation for the heavy metals to guarantee the feasible application in the construction field.
