The effects of MgO, Na2O and SO3 on industrial clinkering process: phase composition, polymorphism, microstructure and hydration, using a multidisciplinary approach

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization Pub Date : 2019-09-01 DOI:10.1016/j.matchar.2019.109809

Monica Segata , Nicoletta Marinoni , Matteo Galimberti , Maurizio Marchi , Marco Cantaluppi , Alessandro Pavese , Ángeles G. De la Torre

{"title":"The effects of MgO, Na2O and SO3 on industrial clinkering process: phase composition, polymorphism, microstructure and hydration, using a multidisciplinary approach","authors":"Monica Segata , Nicoletta Marinoni , Matteo Galimberti , Maurizio Marchi , Marco Cantaluppi , Alessandro Pavese , Ángeles G. De la Torre","doi":"10.1016/j.matchar.2019.109809","DOIUrl":null,"url":null,"abstract":"<div>The present investigation deals with how minor elements (their oxides: MgO, Na2O and SO3) in industrial kiln feeds affect (i) chemical reactions upon clinkering, (ii) resulting phase composition and microstructure of clinker, (iii) hydration process during cement production.Our results show that all these points are remarkably sensitive to the combination and interference effects between the minor chemical species mentioned above.Upon clinkering, all the industrial raw meals here used exhibit the same formation temperature and amount of liquid phase. Minor elements are preferentially hosted by secondary phases, such as periclase. Conversely, the growth rate of the main clinker phases (alite and belite) is significantly affected by the nature and combination of minor oxides. MgO and Na2O give a very fast C3S formation rate at T > 1450 K, whereas Na2O and SO3 boost C2SAfter heating, if SO3 occurs in combination with MgO and/or Na2O, it does not inihibit the C3S crystallisation as expected. Rather, it promotes the stabilisation of M1-C3S, thus indirectly influencing the aluminate content, too. MgO increseases the C3S amount and promotes the stabilisation of M3-C3S, when it is in combination with Na2O. Na2O seems to be mainly hosted by calcium aluminate structure, but it does not induce the stabilisation of the orhtorhombic polymorph, as supposed to occur. Such features play a key role in predicting the physical-mechanical performance of a final cement (i.e. rate of hydration and hardening) when used as a bulding material.</div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"155 ","pages":"Article 109809"},"PeriodicalIF":4.8000,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.matchar.2019.109809","citationCount":"19","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Characterization","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1044580319304620","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CHARACTERIZATION & TESTING","Score":null,"Total":0}

引用次数: 19

Abstract

The present investigation deals with how minor elements (their oxides: MgO, Na₂O and SO₃) in industrial kiln feeds affect (i) chemical reactions upon clinkering, (ii) resulting phase composition and microstructure of clinker, (iii) hydration process during cement production.

Our results show that all these points are remarkably sensitive to the combination and interference effects between the minor chemical species mentioned above.

Upon clinkering, all the industrial raw meals here used exhibit the same formation temperature and amount of liquid phase. Minor elements are preferentially hosted by secondary phases, such as periclase. Conversely, the growth rate of the main clinker phases (alite and belite) is significantly affected by the nature and combination of minor oxides. MgO and Na₂O give a very fast C₃S formation rate at T > 1450 K, whereas Na₂O and SO₃ boost C₂S

After heating, if SO₃ occurs in combination with MgO and/or Na₂O, it does not inihibit the C₃S crystallisation as expected. Rather, it promotes the stabilisation of M₁-C₃S, thus indirectly influencing the aluminate content, too. MgO increseases the C₃S amount and promotes the stabilisation of M₃-C₃S, when it is in combination with Na₂O. Na₂O seems to be mainly hosted by calcium aluminate structure, but it does not induce the stabilisation of the orhtorhombic polymorph, as supposed to occur. Such features play a key role in predicting the physical-mechanical performance of a final cement (i.e. rate of hydration and hardening) when used as a bulding material.

查看原文本刊更多论文

MgO、Na2O和SO3对工业熟化过程的影响:相组成、多态性、微观结构和水化

本研究涉及工业窑料中的微量元素(它们的氧化物:MgO、Na2O和SO3)如何影响(i)熟料时的化学反应，(ii)熟料的相组成和微观结构，(iii)水泥生产过程中的水化过程。结果表明，这些点对上述微量化学物质的组合和干扰作用都非常敏感。在结块时，这里所用的所有工业生料都表现出相同的形成温度和液相量。次要元素优先由次生相(如方长石)承载。相反，主要熟料相(阿利石和白来石)的生长速率受少量氧化物的性质和组合的显著影响。MgO和Na2O在T > 1450 K下形成C3S的速度非常快，而Na2O和SO3促进c2s的形成。加热后，如果SO3与MgO和/或Na2O结合，它不会像预期的那样抑制C3S的结晶。相反，它促进了M1-C3S的稳定，从而间接影响了铝酸盐的含量。当MgO与Na2O结合时，增加了C3S的量，促进了M3-C3S的稳定。Na2O似乎主要是由铝酸钙结构承载的，但它并没有像预期的那样诱导正交晶型的稳定。当用作建筑材料时，这些特征在预测最终水泥的物理力学性能(即水化和硬化速率)方面起着关键作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Materials Characterization 工程技术-材料科学：表征与测试

CiteScore

7.60

自引率

8.50%

发文量

746

审稿时长

36 days

期刊介绍： Materials Characterization features original articles and state-of-the-art reviews on theoretical and practical aspects of the structure and behaviour of materials. The Journal focuses on all characterization techniques, including all forms of microscopy (light, electron, acoustic, etc.,) and analysis (especially microanalysis and surface analytical techniques). Developments in both this wide range of techniques and their application to the quantification of the microstructure of materials are essential facets of the Journal. The Journal provides the Materials Scientist/Engineer with up-to-date information on many types of materials with an underlying theme of explaining the behavior of materials using novel approaches. Materials covered by the journal include: Metals & Alloys Ceramics Nanomaterials Biomedical materials Optical materials Composites Natural Materials.