硅酸盐学报

硅质组分赋存状态对熟料烧成及反应动力学的影响

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王金楠 ¹^,² , 张同生 ¹^,² , 韦江雄 ² , 姚凯凯 ³ , 任雪红 ⁴ , 余其俊 ²

硅酸盐学报 | 低碳水泥与固废资源化利用专题—研究论文 2026,54(5): 1673-1684

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硅酸盐学报 |低碳水泥与固废资源化利用专题—研究论文 2026 , 54 (5) : 1673 -1684

硅质组分赋存状态对熟料烧成及反应动力学的影响

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王金楠¹^,², 张同生¹^,², 韦江雄², 姚凯凯³, 任雪红⁴, 余其俊²

作者信息

^1．华南理工大学，亚热带建筑与城市科学全国重点实验室，广州 510640

^2．华南理工大学材料科学与工程学院，广州 510640

^3．中铁（广州）投资发展有限公司，广州 510308

^4．中国建筑材料科学研究总院有限公司，北京 100024

通讯作者:

张同生（1983—），男，博士，研究员。

作者简介:

王金楠（1997—），男，博士研究生。

Role of Calcium Silicate Hydrate as Silicon Source in Clinkering: Mineral Evolution and Kinetics

Jinnan WANG¹^,², Tongsheng ZHANG¹^,², Jiangxiong WEI², Kaikai YAO³, Xuehong REN⁴, Qijun YU²

Affiliations

^1.State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology, Guangzhou 510640, China

^2.School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China

^3.China Railway (Guangzhou) Investment & Development Co., Ltd., Guangzhou 510308, China

^4.China Building Materials Academy Co., Ltd., Beijing 100024, China

Corresponding Author:

Zhang Tongsheng (1983-), male, Ph.D., Researcher. E-mail: mstszhang@scut.edu.cn

Wang Jinnan (1997-), male, Doctoral candidate. E-mail: wangjinnan97@163.com

出版时间: 2026-04-15 doi: 10.14062/j.issn.0454-5648.20260037

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摘要

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再生微粉（Recycled concrete powder, RCP）作为替代原料，可显著降低水泥熟料制备过程的碳排放。RCP中硅质组分的赋存形式与含量差异明显，其对熟料烧成反应路径、矿物形成及动力学行为的影响机制仍有待厘清。鉴于真实RCP组分复杂，本研究聚焦其中硅质组分的两类典型赋存形态［石英与水化硅酸钙（C-S-H）］，通过水热合成的C-S-H逐步替代生料中的SiO₂，系统研究了硅质组分赋存状态对熟料烧成过程及动力学的影响。结果表明：石英为硅质组分时，硅酸二钙（C₂S）初步形成阶段可由相界面反应模型较好描述，反应速率为0.43 min^-1；C-S-H为硅质来源时，C₂S的可检出形成温度由1000~1100 ℃降至900 ℃，且固相反应在主要阶段的动力学更符合Avrami-Erofeev（A2）模型，反应速率提高至7.6 min^-1。随C-S-H对石英替代比例的提高，熟料中硅酸三钙（C₃S）的生成量显著增加；同时C₂S晶粒尺寸由87 nm细化至66 nm，C₃S晶粒尺寸也由160 nm减小至121 nm，且矿物发育更充分、形貌更规整。上述变化可归因于烧成过程中C-S-H再结晶行为，生成的C₂S微晶促进固相反应成核、降低硅酸盐矿物的生成温度并加速固相反应过程，为生料中引入RCP后的配料优化与烧成制度设计提供了动力学与矿物学依据。

关键词

再生微粉 / 水化硅酸钙 / 矿物演变 / 反应动力学

Abstract

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Introduction

In recent years, Portland cement production in China has exceeded 1.8 billion tonnes per year, while CO₂ emissions from limestone decarbonation and fuel combustion remain high (i.e., ≈1.1 billion tonnes), accounting for ~8% of the national total. Replacing limestone with Ca-rich, non-carbonate solid wastes (e.g., recycled concrete powder, RCP) represents a promising pathway toward low-carbon clinker production. The RCP mainly consists of quartz and hardened cement paste. The RCP with higher paste fractions is reported to have lower clinker formation temperatures. Previous studies indicate that Ca(OH)₂, unhydrated clinker particles, and certain minor elements (e.g., S) can facilitate clinkering. C-S-H is a dominant phase in hardened cement paste (>55%). Upon heating (≈500-700 ℃), C-S-H undergoes dehydration and structural depolymerization/rearrangement, potentially generating reactive Ca-Si intermediates that may affect clinkering reactions. However, most previous work treated a hardened cement paste as an integrated entity, and the specific role of C-S-H in governing clinker mineral formation, reaction kinetics, and microstructural evolution remains insufficiently understood.

To decouple the multiphase effects of RCP, this study used synthetic C-S-H to replace quartz, thereby isolating the contribution of C-S-H to clinkering reactions, phase evolution, and kinetics.

Methods

C-S-H was hydrothermally synthesized using Ca(OH)₂ and SiO₂ nanoparticles at a CaO/SiO₂ molar ratio of 1.2. Its thermal evolution was preliminarily characterized by X-ray diffraction (XRD). C-S-H lost a long-range order at ~800 ℃ and recrystallized into C₂S and wollastonite (CS) after heating to 900 ℃. At 1000 ℃, the crystallite sizes were ~15 nm for C₂S and ~50 nm for CS (the Williamson-Hall method).

Five raw meals were designed with a silica modulus (SM) of 2.8, an alumina modulus (IM) of 1.8, and a lime saturation factor (KH) of 0.91. The reference mix used analytical-grade SiO₂ together with CaCO₃, Al₂O₃·2SiO₂·2H₂O, and Fe₂O₃. In the remaining mixes, C-S-H progressively replaced SiO₂ (and the corresponding fraction of CaCO₃), with increasing the silicon substitution ratio of C-S-H to SiO₂ from 25% to 100% (on a Si basis). Pellets (Φ 30 mm × 7 mm) were pressed at 40 MPa, dried at 105 ℃, heated in a muffle furnace at 10 ℃/min to selected temperatures, and followed by air quenching.

The phase evolution of clinkers was quantified by X-ray diffraction (XRD) coupled with Rietveld refinement using the ICSD structure models and ZnO as an internal standard. To suppress the dominant endotherm from CaCO₃ decarbonation and enhance clinkering-related thermal signals at a high temperature, CaO was used instead of CaCO₃ in the tests of thermogravimetry-differential scanning calorimetry (TG-DSC), and the derived kinetic parameters were interpreted comparatively as apparent values. The non-isothermal TG-DSC measurements were performed at 5-20 K/min in N₂, and apparent activation energies and kinetic models were evaluated by the Flynn-Wall-Ozawa (FWO) isoconversional method.

Results and discussion

Introducing C-S-H into raw meals produces a pronounced exothermic peak associated with C₂S formation at ~870 ℃, consistent with the low-temperature decomposition and recrystallization behavior of C-S-H. When quartz serves as a silicon source, C₂S formation kinetics are well described by a phase-boundary-controlled (R3) model, with an apparent activation energy of 540 kJ/mol. In contrast, when C-S-H serves as a silicon source, the best-fit model shifts to the Avrami-Erofeev (A2), and the higher activation energy (797 kJ/mol) can be attributed to a structural rearrangement coupled with C-S-H recrystallization. The Arrhenius analysis further shows that lnA increases from 54.5 to 84.0; accordingly, the instantaneous reaction rate (dα/dt) at α = 0.5 and T = 900 ℃ increases from 0.43 to 7.60 min^-1, indicating a great kinetic compensation effect likely associated with the disordered/nanostructured nature of C-S-H and the enlarged effective reaction interface.

Consistently, the XRD-detectable onset temperature for C₂S formation decreases from 1000-1100 ℃ (quartz) to 900 ℃ (C-S-H), and the C₂S content is increased by 10-24% at the same sintering temperatures (i.e., 900-1300 ℃). The incorporation of C-S-H also increases the C₃S content by 5-15% at 1350-1450 ℃. Moreover, a high defect density of C-S-H and nanocrystal formation during heating contributes to crystallite refinement, reducing the C₂S crystallite size from 87 nm to 66 nm and the C₃S size from 160 nm to 121 nm.

Mechanistically, C-S-H enhances clinker burnability via (i) structural depolymerization/rearrangement at a lower temperatures, (ii) a higher defect density and early formation of nanocrystalline products that promote C₂S/C₃S nucleation, and (iii) a reduced effective CaO transport requirement because C-S-H (at Ca/Si ratio of 1.2) supplies part of the Ca needed for C₂S formation, thereby shortening the effective CaO diffusion distance.

Conclusions

Using C-S-H as a silicon source could markedly accelerate solid-state reaction kinetics (0.43 min^-1→ 7.60 min^-1), lower the XRD-detectable onset temperature of C₂S formation (1000-1100 ℃→ 900 ℃), and promote the formation of both C₂S and C₃S. In addition, the recrystallization products of C-S-H provided abundant nucleation sites and led to refined silicate crystallites. These findings could offer a mechanistic guidance for clinkering with RCP containing high hardened cement paste (C-S-H-rich) fractions toward low-carbon clinker production.

Key words

recycled concrete powder / calcium silicate hydrate / mineral evolution / reaction kinetics

引用本文

王金楠, 张同生, 韦江雄, 姚凯凯, 任雪红, 余其俊. 硅质组分赋存状态对熟料烧成及反应动力学的影响. 硅酸盐学报, 2026 , 54 (5) : 1673 -1684 . DOI: 10.14062/j.issn.0454-5648.20260037

Jinnan WANG, Tongsheng ZHANG, Jiangxiong WEI, Kaikai YAO, Xuehong REN, Qijun YU. Role of Calcium Silicate Hydrate as Silicon Source in Clinkering: Mineral Evolution and Kinetics[J]. Journal of the Chinese Ceramic Society, 2026 , 54 (5) : 1673 -1684 . DOI: 10.14062/j.issn.0454-5648.20260037

基金

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国家自然科学基金项目(52341201; U24A2048)
广州市重点研发项目(2023B03J1280)

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2026年第54卷第5期

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文章信息

doi: 10.14062/j.issn.0454-5648.20260037

接收时间：2026-01-18
首发时间：2026-09-20
出版时间：2026-04-15

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出版历史

收稿日期：2026-01-18
修回日期：2026-02-07

基金

国家自然科学基金项目(52341201; U24A2048)

广州市重点研发项目(2023B03J1280)

作者信息

^1．华南理工大学，亚热带建筑与城市科学全国重点实验室，广州 510640

^2．华南理工大学材料科学与工程学院，广州 510640

^3．中铁（广州）投资发展有限公司，广州 510308

^4．中国建筑材料科学研究总院有限公司，北京 100024

通讯作者:

张同生（1983—），男，博士，研究员。

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https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20260037

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2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

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