焙烧温度对硅酸钙矿化CO_2的影响  

Effect of Calcinations Temperature on Mineralization of CO_2 with Calcium Silicate

作　　者：绳昊一 吕莉[1] 梁斌[1] 李春[1] 袁博[1] 叶龙泼[1] 岳海荣[1] 王昱飞[2] 朱家骅[1] 谢和平[2] 

机构地区：[1]四川大学化学工程学院,四川成都610065 [2]四川大学CCUS与CO2矿化利用研究中心,四川成都610065

出　　处：《矿产综合利用》2015年第5期76-80,共5页Multipurpose Utilization of Mineral Resources

基　　金：国家自然科学基金重点资助项目(21236004;21336004);国家科技支撑项目(2013BAC12B03);教育部CCUS-CO2矿化利用科技攻关项目

摘　　要：基于CO2矿化利用(CMU)的学术思想,提出了钾长石与氯化钙或硫酸钙焙烧提钾/提钾渣矿化固定CO2的技术路线。但是这两种路线得到提钾渣中硅酸钙(主要物相是硅灰石Ca Si O3和假硅灰石Ca3Si3O9)矿化CO2活性有很大的差异。本文考察了焙烧温度对硅酸钙矿化CO2的影响,结果表明,未焙烧硅酸钙矿化CO2转化率达到95%,随着焙烧温度的升高,硅酸钙的转化率逐渐降低,由900℃的82%逐渐降至1300℃的48%。XRD分析表明,焙烧处理使硅灰石逐渐转化成为更易于与CO2反应的假硅灰石;SEM观察发现,焙烧导致非晶态的硅酸钙颗粒晶化与烧结,比表面积显著地降低。上述两种相反的影响中,比表面积降低的不利因素占据了主导,从而降低了硅酸钙矿化CO2反应的活性。Based on the academic thought of carbon capture and utilization（ CMU）,a novel approach to extraction of potassium via high-temperature roasting of insoluble potassium feldspar with industrial waste calcium chloride or calcium sulfate,followed by carbonation of the potassium-depleted residue for sequestration of CO2 was proposed in our previous studies. In these two studies,however,the reactivity for carbonation of calcium silicates（ main phases wollastonite（ CaSiO3） and pseudowollastonite（ Ca3Si3O9）） contained in the residues differed greatly. In this study,the effect of calcinations temperature of calcium silicate on its carbonation was examined. The results demonstrated that compared with 95% of the carbonation conversion of the un-calcined calcium silicate,the conversion declined rapidly to 82% and 48%,respectively,after calcinations at 900°C and 1300°C. The XRD analysis indicated that the calcium silicate transformed gradually from wollastonite to pseudowollastonite,which was easier to be carbonated than wollastonite,with the rising calcinations temperature. On the other hand,it was observed in SEM analysis that the calcinations resulted in the amorphous calcium silicate particles becoming crystalline and sintering,and the specific surface area remarkably decreasing. Among the two opposite effects,the decreasing specific surface area became dominant. Therefore,the calcium silicate reactivity for CO2 sequestration was significantly reduced

关 键 词：CO2矿化 硅灰石 假硅灰石 

分 类 号：TD989[矿业工程—选矿]