| 摘要: |
| 采用X射线衍射仪（XRD）、扫描电子显微镜能谱（SEM EDS）等确定了循环流化床（CFB）原煤和粉煤灰中钙的赋存物相，并依据不同含钙物相化学反应特性的差异，采用蔗糖和Na2S2O3溶液分步提取法，建立了CFB粉煤灰中含钙物相定量分析方法.结果表明：CFB原煤中钙以白云石形式存在，而CFB粉煤灰中钙的赋存物相为CaO、CaSO4和钙长石；CFB粉煤灰中含钙物相CaO、CaSO4、钙长石的含量分别为503%、245%、544%；CaO和CaSO4大部分存在于CFB粉煤灰表面，钙长石黏附在莫来石及富铁物相表面，且与莫来石共生；钙主要集中在45μm以下粒级的CFB粉煤灰中，其中CaO物相含量达到615%，而58μm以上及45～58μm粒级CFB粉煤灰内CaO物相含量均在100%左右. |
| 关键词: 循环流化床； 粉煤灰 氧化钙 分步提取 赋存状态 |
| DOI：103969/j.issn.1007 9629202103030 |
| 分类号: |
| 基金项目:内蒙古自治区科技重大专项（粉煤灰基土壤调理剂制备及应用示范）；中国工程院咨询研究项目（2019NXZD4）；企业合作项目（粉煤灰中典型重金属赋存规律及安全脱除与处置方法研究） |
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| Occurrence of Calcium in Fly Ash from Circulating Fluidized Bed |
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XIAO Yu1, WANG Xiaohui2, MA Shuhua2, LIU Zhihong1
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1.School of Mining, Guizhou University, Guiyang 550025, China;2.Chinese Academy of Sciences, CAS Key Laboratory for Green Processes and Engineering, Institute of Process Engineering, Beijing 100190, China
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| Abstract: |
| The occurrence phases of calcium in raw coal and fly ash from circulating fluidized bed(CFB) were identified by X ray diffractometer(XRD) and scanning electron microscope energy spectrum(SEM EDS). According to the difference of chemical reaction characteristics of different calcium containing phases, the quantitative analysis method of calcium containing phases in CFB fly ash was established by using the step by step extraction method of sucrose and sodium thiosulfate(Na2S2O3) solution. The calcium in the CFB raw coal exists in the form of dolomite, while in the CFB fly ash in the forms of CaO, CaSO4 and calcium feldspar. The content of CaO, CaSO4 and calcium feldspar in CFB fly ash is 503%, 245% and 544% respectively. It is further found that most of CaO and CaSO4 exist on the surface of fly ash. Calcium feldspar adheres to the surface of a mullite and iron rich phase, and symbiosis with mullite. Calcium is concentrated in the CFB fly ash of 45μm, of which CaO content reaches 615%, while CO content in CFB fly ash greater than 58μm and 4558μm which is about 100%. |
| Key words: circulating fluidized bed fly ash calcium oxide step by step extraction occurrence |
