高贝利特硫铝酸盐水泥的研究

发布时间：2018-01-25 17:20

本文关键词： 高贝利特-硫铝酸盐水泥贝利特外掺离子活化工业试生产　出处：《武汉理工大学》2013年博士论文　论文类型：学位论文

【摘要】：水泥熟料生产的CO2排放约有65%来自石灰石的碳酸盐分解,仅有35%来自燃料的燃烧排放,基于材料本征的排放特点,通过优化工艺提高能效、辅助胶凝材料使用等措施减排的潜力日益减小,而从水泥基材料组成本身进行创新成为全球研究的焦点。本文通过对熟料矿物的形成温度、形成焓、单位矿物CO2排放量等多重因素进行低钙低碳优化设计,实现了不含高钙矿物-阿利特(C3S)、以贝利特(C2S)和硫铝酸盐(C4A3S)为主导矿物的低能耗、低CO2排放C2S-C4A3S-C4AF三元熟料体系(Belite Calcium Sulfo-Aluminate, BCSA)。通过矿物组成优化匹配及晶体的稳定与活化,制备出性能优于但能耗和排放远低于普通硅酸盐水泥的BCSA水泥。与普通硅酸盐水泥相比,BCSA水泥生产过程中可节约石灰石28%和标煤约16%以上,减少CO2排放20%以上,实现了通过水泥基材料创新达到节能降耗的目的。本文利用XRD、红外光谱IR和SEM等方法,围绕BCSA的矿物组成设计、离子掺杂作用机理、工业试生产及其水泥混凝土性能,主要研究了以下内容： (1)熟料低钙组成设计和高温矿相形成研究确定了熟料低钙低碳矿物组成的原则。由C2S-C4A3S-C4AF三元矿物组成的熟料体系里,CaA3S和C2S分别是熟料的早期强度和中后期强度的来源。研究了C2S、C4A3S和C4AF三种矿物的形成温度和最佳范围,阐明了三种矿物的共存温度区间1250-1350℃。研究了熟料的易烧性、主要熟料矿物C4A3S和C2S的形成和结晶发育状况、以及熟料的物理性能。研究表明,BCSA熟料的最佳烧成温度范围是1280-1320℃,在该温度范围内烧制的熟料具有良好的工作性和物理力学性能。 (2) BCSA熟料矿物优化匹配和熟料／石膏作用机理确定了BCSA熟料矿物组成范围为C2S36-56%, C4A3S32-42%和C4AF5-9%。在上述矿物组成范围内,BCSA熟料具有最佳的物理性能,3天和28天抗压强度分别达到34.3MPa和55.1MPa。研究了BCSA熟料与石膏的相互作用机理。石膏掺量显著影响BCSA水泥的性能,确定了石膏最佳掺量范围为12.5-15%。石膏主要是与C4A3S发生反应形成钙矾石。在浆体结构中,钙矾石与其他水化产物一起形成密实的空间网架结构。 (3)离子掺杂对熟料矿物晶体的稳定与活化机理研究 p晶型C2S水化速率慢,早期强度低,一直影响着这种矿物在熟料中的作用。本文着重研究了提高β-C2S活性的方法和作用机理。研究表明,外掺离子Ba2+、P5+和Zn2+等离子均可进入p-C2S晶格,引起晶格畸变,并且在矿物表面发生富集,使得矿物晶体细化,增强了p-C2S的水化反应活性。同时发现在多种矿物共存的熟料体系中,部分外掺离子进入CSA矿物晶格中,引起晶格畸变,提高了CSA水硬性。β-C2S和C4A3S两种矿物共存时,外掺离子影响其活性的显著性依次为：Ba2+P5+Zn2+B3+。掺入Ba2+的熟料制得的水泥,其28d抗压强度达到69.7MPa,比未掺杂空白样强度提高了15MPa(26.5%)。 (4) BCSA水泥工业试生产关键技术的研究利用现有水泥工艺设备和工业原燃料,全球首次在带五级预热器窑的新型干法生产线上进行了BCSA水泥工业化试生产的关键技术研究,实现了该水泥在新型干法生产线的工业化试生产。确定了工业化制备的主要工艺参数,所生产水泥的3d强度达43.7MPa,28d强度达66.9MPa。 (5) BCSA水泥混凝土力学性能及耐久性研究结果表明,BCSA水泥配制混凝土具有良好的力学性能(抗折抗压强度、劈拉强度、轴心抗压强度等)和耐久性能(包括抗渗性、抗冻性、氯离子渗透性、抗硫酸盐侵蚀性、抗碳化性能、体积稳定性等)。这些性能均优于普通水泥配制的混凝土性能。分析表明,BCSA水泥需水量少,浆体内部孔隙率较低,且水化产物中钙矾石形成过程伴随的微膨胀增加硬化浆体结构的致密度。这是BCSA水泥混凝土具有良好的力学性能和耐久性能的主要原因。
[Abstract]:The emission of CO2 cement clinker production of about 65% from the limestone decomposition of carbonate, only 35% from fuel combustion emissions, emissions based on the intrinsic characteristics of the material, by optimizing the process to improve the energy efficiency and emission reduction of auxiliary cementitious materials using measures such as the potential is reduced, and from the cement-based material composition itself has become the focus of global innovation research.
Based on the formation of clinker temperature, enthalpy of formation, unit of mineral CO2 emissions of multiple factors such as low calcium and low carbon optimization design, to achieve a high calcium containing minerals - Alite (C3S), Baillet (C2S) and sulphoaluminate (C4A3S) for low energy consumption dominant mineral, low emission of CO2 C2S-C4A3S-C4AF three Clinker System (Belite Calcium Sulfo-Aluminate yuan, BCSA). The stability and activation by mineral composition and optimized matching crystal, preparation superior performance but the energy consumption and emissions is much lower than that of ordinary portland cement BCSA cement. Compared with ordinary portland cement, BCSA cement production process can save 28% limestone and coal for about 16% above. To reduce CO2 emissions by more than 20%, to achieve the purpose of saving energy through innovation of cement-based materials.
In this paper, we use XRD, infrared spectroscopy IR and SEM to study the mineral composition design of BCSA, the mechanism of ion doping, industrial trial production and the performance of cement concrete.
(1) study on the design of low calcium composition of clinker and formation of high temperature ore phase
The principle of composition of low calcium and low carbon minerals is determined. CaA3S and C2S are the sources of early strength and mid and late strength of clinker in C2S-C4A3S-C4AF three mineral system.
Study on the formation of C2S, temperature and the best range of C4A3S and C4AF three kinds of minerals, the coexistence of three kinds of mineral temperature range of 1250-1350 C was studied. The clinker burnability, formation and development status of the main C4A3S and C2S clinker mineral crystallization, and clinker physical properties. The results show that the optimum BCSA of clinker burning the temperature range of 1280-1320 DEG C, clinker firing in the temperature range and has good physical and mechanical properties.
(2) optimum matching of mineral mineral in BCSA clinker and mechanism of clinker / gypsum
The mineral composition range of BCSA clinker is C2S36-56%, C4A3S32-42% and C4AF5-9%.. In the above mineral composition range, BCSA clinker has the best physical properties, and the compressive strength reaches 34.3MPa and 55.1MPa. on the 3 day and the 28 day respectively.
The interaction mechanism of BCSA clinker and gypsum. Gypsum significantly affect the properties of BCSA cement, gypsum to determine the optimal dosage range of 12.5-15%. gypsum is mainly reacted to form ettringite and C4A3S. The structure of slurry, ettringite and other hydration products together to form a space truss structure compact.
(3) study on the stability and activation mechanism of ion doping on the crystal of clinker mineral
P crystal C2S hydration rate is slow, low early strength, has influenced the effect of the mineral in clinker. This paper focuses on the methods to improve the effect and mechanism of beta -C2S activity. The study shows that the addition of P5+ and Ba2+ ions, Zn2+ plasma can enter into the p-C2S lattice, cause the distortion of crystal lattice, and the mineral surface the contents of mineral crystal refinement, enhance the hydration activity of p-C2S. At the same time found in a variety of minerals clinker system, part of doped ions into CSA crystal lattice, caused by lattice distortion, improve the CSA hard water. Beta -C2S and C4A3S two kinds of minerals, with significant ion effect the activity is as follows: Ba2+P5+Zn2+B3+.
The compressive strength of the cement prepared by the clinker doped with Ba2+ is 69.7MPa, which is 15MPa (26.5%) higher than that of the undoped blank sample.
(4) research on key technology of test production in BCSA cement industry
Use of the existing cement production equipment and industrial raw fuel, for the first time in the world with five stage preheater kiln NSP production line is carried out research on the key technology of BCSA cement production industrialization, realize the industrialization of the cement in the new dry production line production. The main process parameters for industrial preparation were determined, the production intensity of 3D cement reached 43.7MPa, 28d strength of 66.9MPa.
(5) study on mechanical properties and durability of BCSA cement concrete
The results show that the BCSA cement concrete has good mechanical properties (flexural and compressive strength, splitting tensile strength, axial compressive strength) and durability (including impermeability, frost resistance, chloride ion permeability, sulfate resistance, carbonation resistance, volume stability, etc.). These properties are the properties of concrete better than ordinary cement. The analysis shows that BCSA need less water cement slurry, low porosity, and the hydration products of ettringite formation process with the increase of the density of the micro expansion structure of hardened paste. This is the main reason of BCSA cement concrete has good mechanical properties and durability.

【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TQ172.7

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