【摘要】 本研究以粉煤灰（CFA）为原料，通过碱熔-水热法实现了高活性可溶性硅的提取与纳米级羟基硅酸钙（CSH）的可控制备，为煤基固废的高值化利用提供了可行路径。具体流程包括：采用Na₂CO₃作为活化剂，在850℃煅烧2 h，煅烧产物与水以固液比1∶10溶解，80℃水浴90 min后固液分离，得到提硅液，硅提取率为45.7%；提硅液与CaCl₂在80℃水浴中反应3 h，成功合成CSH。缓释研究表明：所制备的CSH在柠檬酸溶液中硅释放行为符合Higuchi扩散模型，最大硅缓释浓度为350 mg/L；在不同pH值环境下CSH亦表现出持续释放特性，当pH值为6和8时，硅缓释浓度在第3天分别达到150与100 mg/L。本研究实现了CFA的低成本资源化转化，制备的CSH对推动固废绿色资源化利用和农业可持续发展具有重要意义。更多还原

【Abstract】 This study utilized coal fly ash（CFA） as raw material to achieve the extraction of highly reactive soluble silicon and the controllable synthesis of nano-sized calcium silicate hydrate（CSH） through an alkali fusion-hydrothermal method, providing a feasible pathway for the high-value utilization of coal-based solid waste. The specific procedure included: using Na₂ CO₃ as an activator and calcining at 850 ℃ for 2 h. The calcined product was dissolved in water at a solid-liquid ratio of 1∶10. After 90 min in an 80 ℃ water bath, solid-liquid separation yielded a silicon extraction solution. This process achieves a silicon extraction rate of 45. 7%. The silicon extraction solution was then reacted with CaCl₂ in an 80 ℃ water bath for 3 h to successfully synthesize CSH. Slow-release studies demonstrate that the silicon release behavior of the as-prepared CSH in citric acid solution follows the Higuchi diffusion model, with a maximum silicon slow-release concentration of 350 mg/L. It also exhibits continuous release characteristics under different pH conditions, at pH value of 6 and 8, the silicon slow-release concentration reached 150 and 100 mg/L, respectively, on the third day. This research achieves the low-cost resource conversion of CFA, and the prepared CSH holds promise for promoting the green resource utilization of solid waste and the sustainable development of agriculture.更多还原