水泥窑协同处置技术有望实现含氟污泥的高值化利用,但含氟污泥中含有的CaF2和多种杂质重金属离子都具有一定的矿化作用,容易导致所制备水泥熟料的性能波动且难以稳定控制.鉴于此,探究了含氟污泥中CaF2与多种重金属离子共掺对水泥熟料主要矿物硅酸三钙(C3S)形成及水化特性的协同影响.研究表明:相较于CaF2单掺或多种重金属离子复掺,两者共掺能显著减少C3S中的f-CaO含量,促使C3S由低对称性向高对称性的多晶转变,使颗粒尺寸细化,表观缺陷数量明显增多.CaF2与多种重金属离子共掺可提升C3S的初始水化速率,增大C3S的3d水化放热总量,但会使诱导期结束时间延长约8.1 h.
The synergistic effect of co-doping of fluorine and various heavy metal ions on the formation and hydration process of C2S
The co-processing technology of cement kiln is expected to realize the high-value utilization of fluorine-containing sludge.However,CaF2 and a variety of impurity heavy metal ions containeal in the fluorine-containing sludge has a certain miner-alization effect,which is easy to cause the performance of the prepared cement clinker to fluctuate and difficult to control stably.In view of this,this paper systematically explored the synergistic effect of CaF2 and various heavy metal ions in fluorine-containing sludge on the formation and hydration characteristics of tricalcium silicate(C3S),the main mineral of cement clinker.The results show that compared with CaF2 single doping or multiple heavy metal ions co-doping,the co-doping can significantly reduce the content of f-CaO in C3S,promote the transformation of C3S from low symmetry to high symmetry,refine the particle size,and in-crease the number of apparent defects.The co-doping of CaF2 and various heavy metal ions can increase the initial hydration rate of C2S and increase the total amount of 3 d hydration heat release of C3S,but it will prolong the end time of the induction period(prolonged about 8.1 h).
cement kiln co-processingfluorine-containing sludgetricalcium silicateheavy metal ionshydration reaction
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