摘要
以氧氯化锆生产排放的酸性锆硅渣为主要原料,经脱酸除杂得到硅凝胶,按nCaO∶nSiO2=1∶1、W∶S（水/固质量比）=30∶1与消石灰加水混合均匀,采用动态水热法合成硬硅钙石。利用XRD、FT-IR、SEM等方法,研究了硬硅钙石的合成条件和合成机理。结果表明,锆硅渣经消石灰中和水洗可有效脱酸除杂,并可降低硅凝胶的[SiO4]4-聚合度,提高其反应活性。用此硅凝胶作硅源,在200℃下反应6 h即可合成长径比为40~60的纯相纤维状硬硅钙石。反应过程中,硬硅钙石系由CSH凝胶直接转化而成,未经历托贝莫来石相的过渡。
Xonotlite was synthesized from the dynamic hydrothermal reaction of nCaO∶ nSiO2in the molar ratio of 1∶ 1 and the mass ratio of water-solid of 30 ∶ 1 using silica gel from the pretreated byproduct of zirconium oxychloride as silicon source reagent. Synthesis conditions and synthesis mechanism of xonotlite were investigated by XRD, FT-IR and SEM techniques. The results show that the [SiO4]4-polymerization degree of the silica gel treated by lime hydrate neutralization can be reduced,and the reactivity of the gel is enhanced correspondingly. Fibrous xonotlite crystals can be synthesized completely at 200 ℃ for 6 h using so-pretreated gel as Si starting material,the ratio of length-diameter of which is between 40 ~ 60. Furthermore,no tobermorites occurred in the whole procss of synthesis,and the xonotlite was converted derectly from the CSH（i. e. CaO-SiO2-H2O） gel formed by silica and hydrate lime under such experimental conditions.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2014年第4期997-1002,1008,共7页
Journal of Synthetic Crystals
基金
山东省自然科学基金(ZR2012EMM016)
关键词
动态水热法
锆硅渣
硬硅钙石
[SiO4]4-聚合度
合成机理
dynamic hydrothermal method
zirconium silicon residue
xonotlite
polymerization degree of [SiO4]4-
synthesis mechanism
