Abstract: The humic acid with average particle size of 60 nm was prepared by alkali-solution and acid-isolation and high shearing technology using weathered coal as raw material.The optimum condition to prepare nanoscale humic acid was obtained through orthogonal experiment：reaction temperature 60℃，reaction time 150 min，ammonia concentration 25%(mass)，solid-to-liquid ratio 1∶10，and addition amount of crystalization adjusting agent 0.15% of the total reaction solution.The size distribution，chemical structure，crystallization properties，morphology，specific surface area of nanometer humic acid were characterized by laser particle size analyzer，FTIR，GPC,XRD，SEM，and specific surface area analyzer(BET).The results showed that the particle size of the sample was well distributed，meanwhile，the sample had good dispersion，the average particle size was 60 nm，specific surface area was 110.31 m2·g-1,and relative molecular weight was 119.Double bonds in the structure，specific surface area and functional groups increased obviously.

Key words: nanoscale humic acid, crystalization adjusting agent, particle size, weathered coal, alkali-solution and acid-isolation

摘要： 以风化煤为原料，采用碱溶酸析沉淀法配加高剪切技术制备了平均粒径为60 nm的腐殖酸。通过正交实验得出制备纳米腐殖酸最优化工艺条件为:反应温度60℃，反应时间150 min，氨水质量分数25%，固液比1∶10，晶粒调整剂加入量为反应溶液质量的0.15%，并用激光粒度分析仪、红外光谱仪(FTIR)、凝胶色谱分析仪(GPC)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)及比表面积分析仪(BET)对产物纳米腐殖酸的粒径分布、化学结构、结晶性能、分子量大小、形貌、比表面积等进行表征。结果表明:粒度分布均匀，分散性良好，平均粒径为60 nm，比表面积为110.31 m2·g-1，数均相对分子量为119，且双键结构和官能团含量明显增加，形状呈球形，比表面积增大，分子质量减小。

关键词: 纳米腐殖酸, 晶粒调整剂, 粒径, 风化煤, 碱溶酸析沉淀法