硅酸钾碱液水热合成针状硅灰石反应历程  

Hydrothermal Synthesis of Acicular Wollastonite from Potassium Silicate Solution

作　　者：罗征[1,2] 马鸿文 杨静[1] 

机构地区：[1]中国地质大学(北京)材料科学与工程学院,北京100083 [2]昊青新材(北京)技术有限公司,北京100083

出　　处：《硅酸盐学报》2017年第11期1679-1685,共7页Journal of The Chinese Ceramic Society

基　　金：中国地质调查项目(12120113087700);中央高校基本科研业务费(53200859555)资助项目

摘　　要：利用钾长石–KOH–H_2O体系分解反应所得硅酸钾碱液合成针状硬硅钙石,用作合成硅灰石的前驱体。采用OLI Analyzer 9.2软件模拟K2O–CaO–SiO_2–H_2O体系化学平衡,预测了合成硬硅钙石的初始CaO/SiO_2摩尔比、反应温度和液固比范围。在此基础上通过单因素实验,确定了合成硬硅钙石的优化条件。反应历程为:水合硅酸钙→雪硅钙石→雪硅钙石+硬硅钙石→硬硅钙石。合成的硅灰石保持了硬硅钙石的针状形貌,分散较均匀,长约10~15μm,直径约300 nm,长径比约40,符合建材行业一级品标准。Xonotlite, as a precursor for synthesizing acicular wollastonite, was synthesized using K-feldspar alkai-leaching filtrate as a silicon source. The chemical equilibrium in the system of K2O-CaO-SiO2-H2O was simulated by a thermodynamical soRware named OLI Analyzer 9.2, predicting the effects of initial CaO/SiO2 molar ratio, reaction temperature, and liquid-solid ratio as well. The optimal conditions and reaction process of synthesis of xonotlite were determined at the predicted parameters. The reaction process ofxonotlite from the alkai-leaching filtrate is calcium silicate hydrate → tobermorite → tobermorite ＋ xonotlite → xonotlite. The size of resultant acicular wollastonite is 10-15 μm in length and approximately 300 nm in diameter, and the product is conformed as a prime standard material in building materials industry.

关 键 词：钾长石 硬硅钙石 硅灰石 绿色合成 

分 类 号：TQ443.5[化学工程—化学肥料工业]