3CaO·2SiO2高温固相反应生成机理及稳定性|裴健男,潘晓林,崔维学,于海燕,涂赣峰-《中国有色金属学报》官方网站|全网首发|论文开放获取

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中国有色金属学报

ZHONGGUO YOUSEJINSHU XUEBAO

第30卷第12期总第261期 2020年12月

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文章编号：1004-0609(2020)-12-2963-08

3CaO·2SiO₂高温固相反应生成机理及稳定性

裴健男^{1, 2}，潘晓林^{1, 2}，崔维学²，于海燕^{1, 2}，涂赣峰^{1, 2}

(1. 东北大学多金属共生矿生态化冶金教育部重点实验室，沈阳 110819；
2. 东北大学冶金学院，沈阳 110819)

摘要: 为了降低烧结法生产氧化铝配钙量和提高生成硅酸钙稳定性，系统研究3CaO·2SiO₂ (C₃S₂)在高温烧结过程中的生成动力学、转变机理以及在铝酸钠溶液中的稳定性。研究表明：在CaO-SiO₂二元体系中，CaO和SiO₂摩尔比(C/S)为1.5:1时物料的非等温烧结过程主要分为CaO·SiO₂ (CS)和2CaO·SiO₂ (C₂S)的生成与转化、CS和C₂S转化成C₃S₂以及C₃S₂分解为C₂S_.和CS三个阶段；在1460 ℃保温1 h时，烧结产物中C₃S₂含量达到最大，为75.6%；延长保温时间促进C₃S₂的生成，并降低C₃S₂的生成温度。C₃S₂的生成反应控制步骤为二级化学反应控制，其活化能为339.67 kJ/mol，指前因子为1.31×10⁹ s^-1。烧结产物在铝酸钠溶液中的稳定性随着C₃S₂含量的升高而增强，硅酸钙化合物的稳定性顺序为：C₃S₂＞C₂S＞CS。

关键字: 硅酸钙；固相反应；动力学；稳定性；烧结法

Formation mechanism and stability of 3CaO·2SiO₂ during high-temperature solid-state reaction

PEI Jian-nan^{1, 2}, PAN Xiao-lin^{1, 2}, CUI Wei-xue², YU Hai-yan^{1, 2}, TU Gan-feng^{1, 2}

（1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral, Ministry of Education, Northeastern University, Shenyang 110819, China;
2. School of Metallurgy, Northeastern University, Shenyang 110819, China）

Abstract:In order to reduce the lime addition and improve the stability of calcium silicates in alumina production by the sinter process, the formation kinetics, transformation mechanism and stability of 3CaO·2SiO₂(C₃S₂) during high- temperature sintering process were investigated. The results show that the non-isothermal sintering process can be divided into three stages in the CaO-SiO₂ binary system with the CaO to SiO₂ molar ratio (C/S) of 1.5:1, the formation and transformation of CaO·SiO₂ (CS) and 2CaO·SiO₂ (C₂S), the transformation of CS and C₂S into C₃S₂, and the decomposition of C₃S₂ into C₂S and CS. The content of C₃S₂ in the sintered product reaches the highest value of 75.6% when the sintering temperature is 1460 ℃ and the holding time is 1 h. The prolonging of holding time can promote the formation of C₃S₂ and reduce its generation temperature. The formation process of C₃S₂ follows the second-order chemical reaction model, and the corresponding apparent activation energy and the pre-exponential factor are 339.67 kJ/mol and 1.31×10⁹ s^-1, respectively. The stability of the sintered products in sodium aluminate solution increases with the increase of C₃S₂ content, and the stability order of calcium silicate compounds is C₃S₂＞C₂S＞CS.

Key words: calcium silicate; solid state reaction; formation kinetics; stability; sinter process

ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK

ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW