电解锰渣陶粒共烧结温度影响机理研究

Influence Mechanism of EMR Ceramsite Co-sintering Temperature

基于探究电解锰渣制备陶粒最佳资源化处置途径,关注烧结温度对陶粒制备工艺的影响因素水平。以电解锰渣(EMR)、粉煤灰(CFA)、珍珠岩(P)为原料,采用不同共烧结温度制备陶粒,探究共烧结温度对陶粒物理性能的影响。通过XRD、SEM-EDS、TG-DTG-DSC技术手段表征陶粒物相组成、微观结构及元素分布、物相转变,分析共烧结温度对陶粒性能的关键作用机理。结果表明,共烧结温度升高对筒压强度具有增效,对1 h吸水率、软化系数、球形系数具有减效,最佳共烧结温度为1160℃。分析显示:EMR中二水石膏在共烧结过程中发生分解与排气,产生CaO。硅灰石和钙铝黄长石发生晶型转变产生钙长石,提高了陶粒的强度,且钙长石的含量与共烧结温度和筒压强度成正比。在共烧结过程中,“过烧”出现的液相包覆晶体会提高陶粒强度,但陶粒球体变形却导致真气孔率有所下降。共烧结陶粒通过形成锰钙辉石来实现Mn的固化,陶粒浸出毒性固化率为99.92%,且无放射性。因此,利用EMR制备陶粒是安全可靠的。

Based on the exploration of the best resource disposal approach for ceramsite preparation from electrolytic manganese slag, the influence factor level of sintering temperature on ceramsite preparation process was concerned. It is of great significance to explore the influence of sintering temperature on ceramsite preparation process. In this work, electrolytic manganese residue(EMR), coal fly ash(CFA) and perlite(P) were used as raw materials to prepare ceramsite at different co-sintering temperatures to explore the influence of co-sintering temperature on the physical properties of ceramsite. XRD, SEM-EDS and TG-DTG-DSC were used to characterize the phase composition, microstructure, element distribution and phase transition of ceramics, and the mechanism of co-sintering temperature on the properties of ceramics was analyzed. The results show that the increase of co-sintering temperature can enhance the pressure strength of cylinder, and reduce the 1 h water absorption, softening coefficient and spherical coefficient. The optimal co-sintering temperature is 1 160 ℃. In EMR, gypsum dissolves and exhauts gas during co-sintering, resulting in the generation of CaO. The crystalline transformation of wollastonite and gehlenite produces anorthite, which increases the strength of ceramsite, and the content of anorthite is proportional to the co-sintering temperature and the pressure strength of cylinder. In the co-sintering process, the liquid phase of ‘overfiring’ coats the crystal, which can further improve the strength of ceramsite, but due to the ceramsite sphere deformation, its comprehensive performance is reduced. The solidification of Mn is realized by the formation of bustamite calcian in co-sintered ceramsite. The solidification rate of ceramsite leaching toxicity test is 99.92%, and there is no radioactivity. Therefore, the preparation of ceramsite by EMR is safe and reliable.