煤灰酸浸渣碳分法制备纳米白炭黑性能研究

为实现煤灰渣资源化高效利用，本文以煤灰酸浸提铝后的高硅残渣经焙烧制得的Na₂SiO₃溶液为原料，采用碳分法制取高附加值的纳米白炭黑。通过单因素法，采用比表面积测试法（BET）、邻苯二甲酸二丁酯（DBP）吸油值测定、透射电镜（TEM）、红外光谱分析（FTIR）、X衍射分析（XRD）等分析表征手段，研究不同的实验条件对制得的纳米白炭黑性能的影响，得到碳分法制取纳米白炭黑的最佳实验工况。实验表明，当硅酸钠溶液中SiO₂质量分数为2%、CO₂通气速率为0.5/min、溶液反应温度为65~75℃、反应终点pH为8时，通过陈化、过滤、洗涤、共沸蒸馏、烘干后，可得到粒径为20~40nm、DBP吸油值为3.10mL/g、比表面积为250m²/g、质量分数91.88%的性能最优纳米白炭黑。

Performance study of precipitated nano-silica from acid leaching residue of coal ash by carbonation method

To achieve its resource-oriented utilization of coal ash,The carbonation method was chosen to prepare high value-added nano-silica aerogel with Na₂SiO₃ solution as raw materials by calcinating the acid leaching residue,which was generated after aluminum extraction of coal ash. One-factor method was adopted to explore the preparation factors affecting the product properties through single factor method to get the optimal reaction conditions. Specific surface area test(BET),determination of oil absorption,Transmission electron microscope(TEM),Fourier Transform infrared spectroscopy(FTIR) and X-ray diffraction(XRD) means were used to characterize the properties of nano-silica. The results showed that 2% of SiO₂,0.5min^-1 of CO₂ ventilation,65-75℃ of reaction temperature and 8 of reaction end pH were the optimum reaction conditions of carbonation. Under the optimum conditions and after aging,filtration,lavation,azeotropic distillation and 120℃ drying,the 20-40nm loose nano-silica with 250m²/g specific area,3.10mL/g oil absorption of DBP and 91.88% mass fraction were prepared.