学术文化活动

报告题目：The potential of turning low-grade UK clays into supplementary cementitious materials for producing low-carbon cements

主 讲：白云 教授

时 间：4月24日 上午10：30

地 点：C2-318

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白云，2004年博士毕业于英国贝尔法斯特女王大学 (Queen’s University Belfast)， 并于2004-2007年在英国谢菲尔德大学(The University of Sheffield) 工程材料系从事博士后研究工作。2007年受聘于英国贝尔法斯特女王大学担任土木工程讲师(Lecturer in Civil Engineering) 职位。2012年起任职伦敦大学学院（University College London, 简称UCL）土木、环境和测绘系(Department of Civil, Environmental & Geomatic Engineering)，先后担任材料方向高级讲师 (Senior Lecturer in Materials) 及Reader in Materials，并于2018年晋升为建筑材料讲席教授(Chair in Construction Materials)。白云教授现为英国高等教育学会 (FHEA)，英国混凝土学会(FICT)及英国材料、矿物及采矿学会(FIMMM)的会士, 伦敦大学学院先进和创新材料中心主任。曾先后担任UCL土木、环境和测绘系土工及材料学部主任及土木工程副主任。主持及参与科研项目20余项, 主持并参与组织国际学术会议近60余次，发表学术论文近180余篇。主要从事新型低碳胶凝材料、混凝土结构耐久性和核废料固化等方面的研究。

报告主要内容：波特兰水泥年产量达41亿吨，预计2050年增长12%-13%，其生产因熟料制造的石灰石脱碳和能源消耗将释放全球5%-7%的二氧化碳，通过辅助胶凝材料（SCMs）替代熟料是关键减碳途径。全球丰富的粘土资源有望推进新型SCMs用以缓解传统材料短缺的问题，本讲座针对煅烧低品位粘土在低碳水泥中的应用效果，深入探讨了其开发过程中的技术机遇与产业化挑战。

As the most important material for human being, Portland Cement (PC), with an estimated annual production of 4.1 billion tonnes and projected increase by 12-13% by 2050, is responsible for approximately 5-7% of global CO2 emission. As the embodied CO2 emission arising from PC is mainly attributed to the production of clinker due to the decarbonation of limestone and consumption of large amounts of fuel and energy, one of the most effective approaches to reducing the carbon footprint of PC is to replace clinker with supplementary cementitious materials (SCMs), such as fly ash and ground granulated blast furnace slag (GGBS) which are the by-products from thermal power plants and steel industry, respectively. However, with the closing down of the last coal-fired thermal power plant and shutdown of the final blast furnace at Tata Steel’s plant in the UK both on 30th September 2024, the UK construction industry is currently facing imminent crisis due to the serious shortage of traditional SCMs, such as fly ash and GGBS. Alternative sources of SCMs are, therefore, desperately required to sustain the UK's production of low carbon cements.

Unlike the availability of fly ash and GGBS which are heavily dependent upon the relevant industry, clay resources are abundant on this planet. Clay is a raw material common to three foundation industries, namely, cement, ceramics and paper. Higher-grade clays such as China clay are extracted for the manufacture of white ceramics and paper. Medium-grade clays are extracted to manufacture ceramics such as bricks and tiles, whereas lower-grade clays are extracted and utilised by the UK cement industry to produce Portland cement clinker. Waste derived clay material is generated during the extraction of higher-grade clays and through the production and use of medium-grade clays (waste bricks/brick fines).

This presentation will report the key findings from a £1.4M Innovate UK ISCF TFI large collaborative R&D project which explored the potential of turning waste derived low-grade UK clays into alternative SCMs to develop novel low-carbon cements. The results show that most of these low-grade clays contain a variety of clay minerals (e.g., kaolinite, illite and montmorillonite) and the type and content of these mineral vary depending on their origin. In addition, considerable amounts of impurities also exist, including calcite, quartz and pyrite. However, under optimal calcination conditions, the reactivity of these low-grade UK clays can be enhanced, showing comparable, and even better, performance in compressive strength than fly ash blended cement. Based on the results obtained from this project, the opportunities and challenges of developing low-carbon cements with calcined low-grade clays will also be discussed.