钠钙协同活化煤矸石长效硅肥的制备及释放特性

许洪飞; 周建民; 税永红; 苏灵

文章摘要

钠钙协同活化煤矸石长效硅肥的制备及释放特性

Preparation and release characteristics of long-lasting silicon fertilizer for coal gangue activated by sodiumcalcium synergy

Received:January 13, 2025

DOI：10.13254/j.jare.2025.0034

中文关键词: 煤矸石，有效硅，活化，毒性

英文关键词: coal gangue, effective silicon, activation, toxicity

基金项目:四川省科技计划项目（2021YFG0262）；成都纺织高等专科学校人才资助项目（RCXM22003）；成都纺织高等专科学校重点研发项目（2022fzlkb05）

Author Name	Affiliation	E-mail
Xu Hongfei	Key Laboratory of Solid Waste Ecological Low Carbon Resource Utilization, Chengdu Textile College, Chengdu 611756, China Chengdu Xinchen New Material Technology Co., Ltd., Chengdu 611400, China
Zhou Jianmin	Key Laboratory of Solid Waste Ecological Low Carbon Resource Utilization, Chengdu Textile College, Chengdu 611756, China School of Environmental Science and Engineering, Southwest Jiaotong University, Chengdu 611756, China	zhjm12805@126.com
Shui Yonghong	Key Laboratory of Solid Waste Ecological Low Carbon Resource Utilization, Chengdu Textile College, Chengdu 611756, China	fxsyh@qq.com
Su Ling	Key Laboratory of Solid Waste Ecological Low Carbon Resource Utilization, Chengdu Textile College, Chengdu 611756, China

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中文摘要:

针对煤矸石堆积污染与低碳硅肥原料资源短缺问题，本研究采用钠-钙协同热活化煤矸石制备长效缓释型硅肥，通过SEM、FTIR、XRD多尺度表征，揭示了活化过程的物相重构机制与界面演化规律；结合释放动力学模型评估了有效硅的释放特性，并解析了重金属环境风险。结果表明：煅烧温度为1 000℃，Na₂CO₃∶ CaCO₃∶煤矸石质量比为0.3∶0.3∶1，保温时间为140 min条件下，样品中的有效硅含量达到41.25%，活化率为81.14%；助剂协同热活化使煤矸石形成松散多孔结构；高温下活性SiO₂与不稳定偏高岭石经与助剂发生配位重组，生成了霞石、沸石、硅酸钙等酸溶性新物相，驱动硅的高效溶出。释放动力学研究表明，七次多项式方程较Logistic方程更精准表征有效硅释放量与时间的定量关系（R²>0.99），证实其长效缓释特性。重金属释放毒性测试显示，Cu²⁺、Zn²⁺、Pb²⁺、Cr⁶⁺最大释放浓度分别为0.167 mg·L^-1、0.431 mg·L^-1、42.6 μg·L^-1和5.445 mg·L^-1，符合《肥料中有毒有害物质的限量要求》（GB 38400—2019）限值要求。本研究为煤矸石高附加值综合利用开辟了高效新途径。

英文摘要:

To address the issues of environmental pollution from coal gangue accumulation and the shortage of raw materials for low-carbon silicon fertilizers, this study proposed the use of sodium –calcium synergistic thermal activation of coal gangue to prepare a long-acting, slow-release silicon fertilizer. Through multi-scale characterization methods including SEM, FTIR, and XRD, the study revealed the mechanisms of phase reconstruction and interfacial evolution during the activation process. The release characteristics of available silicon were evaluated using release kinetics models, and the environmental risks associated with heavy metals were also analyzed. The results showed that under optimal conditions：calcination temperature of 1 000 ℃, a mass ratio of Na₂CO₃∶CaCO₃∶coal gangue of 0.3∶0.3∶1, and a holding time of 140 minutes, the available silicon content reached 41.25%, with an activation rate of 81.14%. The synergistic activation with additives led to the formation of a loose, porous structure in the coal gangue. Unde high temperature active SiO 2 coordinated with unstable metakaolinite, and additives through coordination, resulting in the formation of acid-soluble new phases such as nepheline, zeolite, and calcium silicate, which significantly enhanced silicon dissolution.Release kinetics analysis demonstrated that a seventh-order polynomial equation provided a better quantitative fit for the relationship between available silicon release and time（R²>0.99）compared with the Logistic model, confirming the slow-release characteristics of the fertilizer. Toxicity tests on heavy metal leaching revealed maximum concentrations of Cu²⁺（0.167 mg·L^-1）, Cr⁶⁺（5.445 mg·L^-1）, Pb²⁺（42.6 μg·L^-1）, and Zn²⁺（0.431 mg·L^-1）, all compliant with the limits specified in Limitation Requirements of Toxic and Harmful Substance in Fertilizers（GB 38400—2019）. This research provides a highly efficient approach for the high-value utilization of coal gangue.

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