基于原料中二氧化硅结晶特性的硅酸盐水泥熟料形成化学

Reduction of energy consumption and improvement of quality of Portland cement clinker can be achieved by optimizing raw materials, optimizing raw meal proportioning and improving equipment. However, little study has been performed in view of the mineralogical characteristics of raw materials, especially siliceous materials. Up to now, the effects of crystal characteristics of SiO2 in siliceous materials on the clinker formation are still unclear. What’s more, many different kinds of siliceous materials are used in cement industry nowdays. So it becomes difficult to improve clinker formation by takeing advantages of the crystal characteristics of siliceous materials. Therefore, based on our previous work, this project will begin with investigation of mineralogical characteristics of various siliceous materials by XRD combined with Rietveld method, and then, the effects of Si-O structure, trace components, quartz content, quartz crystallinity, quartz grain size and phase transformation of quartz on clinker formation, structure and properties, and their relationships will be studied from the CaO-SiO2 binary system(silicate mineral) to CaO - SiO2, Al2O3- Fe2O3 quaternary system(clinker). The results will be helpful for the efficient application of siliceous raw materials in cement industry. It can promote reduction in the energy consumption and improve both quality and output of clinkers. Besides, it will also provide scientific basis for the production and use of other types of cement. The basic theory of cement clinker chemistry will be greatly enriched, having important theoretical and practical values.

优选矿物原料、优化生料配比和改进工艺装备是降低水泥生产能耗、提高熟料质量的有效途径。但从优选矿物原料，尤其是硅质原料入手的此类研究极其缺乏。目前基于硅质原料中二氧化硅（SiO2）结晶特性的熟料形成化学尚不明确。加之当前硅质原料来源复杂、种类繁多。因此，通过硅质原料的矿物特性改善熟料烧成成为难点。为此，申请人在前期工作基础上，采用XRD结合Rietveld方法等，从硅质原料中SiO2结晶特性入手，由CaO-SiO2二元单矿体系，到CaO-SiO2-Al2O3-Fe2O3四元熟料体系，系统研究硅质原料中Si-O结构、微量组分、石英含量 、结晶度、晶粒尺寸及相变等对熟料形成、组成结构及性能的影响及机理，阐明其相互关系。项目成果有助于企业合理高效应用硅质原料、降低熟料能耗、提高熟料质量，并为其他品种水泥的生产及应用提供借鉴。研究成果丰富了水泥熟料化学的应用基础理论，具有重要的理论价值和应用前景。

水泥行业作为我国主要的高能耗、高排放产业，是工业领域节能减排的重点和难点。优选矿物原料、优化生料配比和改进工艺装备是降低水泥生产能耗、提高熟料质量的有效途径。但从优选矿物原料，尤其是硅质原料入手的此类研究极其缺乏。二氧化硅（SiO2）是硅酸盐水泥生料的主要成分，其赋存于原料中的结晶特性对熟料烧成能耗及熟料质量具有决定性的影响。本项目从硅质原料中二氧化硅结晶特性入手，通过广泛收集和表征不同地域和种类硅质原料，结合化学试剂单矿物，系统研究了硅质原料中Si-O结构、微量组分、石英含量、晶型、结晶度及晶粒尺寸对熟料形成、组成结构及性能的影响及机理。结果表明，随着硅质原料中SiO2含量的增加，石英晶体含量增加且尺寸增大；硅酸盐矿物的含量逐渐减少，且其Si-O骨架结构由简单的层链状结构转变为复杂的架状结构。Si-O结构较简单的硅质原料矿物，更容易解聚出[SiO4]四面体，在熟料烧成的固相反应阶段更容易与CaO反应形成C2S，从而促进硅酸盐熟料矿物生成。我国南方原料较北方原料含有更多的高岭石等层链状硅酸盐矿物，更有利于熟料烧成。硅质原料中伴生MgO和K2O等微量组分较外加微量组分对熟料烧成的影响更显著。α-方石英制备的生料易烧性好于α-石英，而石英玻璃在固相反应阶段的反应活性较差，但在液相出现后，其反应活性逐渐提升。项目提出了评价硅质原料反应活性的方法，发现了硅质原料的细度与粉磨时间存在指数函数关系,形成了一种物料的易磨性评价方法和物料细度或粉磨时间的预测方法。项目成果有助于企业合理高效应用硅质原料、降低熟料能耗、提高熟料质量，并为其他品种水泥的生产及应用提供借鉴。研究成果丰富了水泥熟料化学的应用基础理论，具有重要的理论价值和应用前景。