陕西黄陵风化煤中腐植酸的提取工艺

The humic acid extraction process of Huangling weathered coal in Shaanxi province

为研究不同提取工艺对腐植酸提取率的影响,以陕西黄陵风化煤为原料,盐酸活化处理风化煤,再分别采用碱溶酸析、氧解、催化法提取腐植酸,确定最佳工艺条件.结果表明风化煤经过盐酸活化后,游离腐植酸增加,使腐植酸提取效果增强,其中盐酸质量分数18%,活化时间25min时,活化效果最佳.以腐植酸提取率为指标,碱溶酸析法最佳提取条件为:18%的盐酸煮沸25min,碱液浓度0.8mol/L,固液比1∶12,沸水浴时间60min;氧解法最佳提取条件为:22%的过氧化氢,0.5mol/L的碱溶液,1∶8的固液比和30min的沸水浴;催化法最佳提取条件为:以NHPI为催化剂,0.3mol/L的碱液,1∶10的固液比和30min的沸水浴时间.3种方法中催化法提取的腐植酸E_4/E_6值最小,后期以催化法提取腐植酸为最佳.

In order to study the effect of different humic acid extraction process on the extraction rate,the Huangling weathered coal in Shaanxi province is taken as the raw material.The hydrochloric acid is first used to activate weathered coal.Then the humic acid is extracted from the weathering coal through the three methods of alkali soluble acid,oxygen and catalytic methods to determine the optimum extraction process respectively.The results indicate that the free humic acid of weathered coal is increased after hydrochloric acid activation and the extraction rate of humic acid is increased.The activation efficiency is the best when the 18% hydrochloric acid concentration and 25 min activation.The optimum process condition of highest extraction rate by acid soluble alkali chromatography method is 18% of hydrochloric acid,25 min boiling time,0.8 mol/L NaOH concentration,1∶12ratio of solid to liquid,60 min boiling water bath.The optimum process condition of oxygen method is 22% hydrogen peroxide,0.5mol/L alkali solution,1∶8ratio and 30 min boiling water bath time.The optimum process condition of catalytic method is using NHPI catalyst,0.3 mol/L NaOH,1∶10ratio and 30 min boiling water bath time.The E4/E6 value of catalytic method is smallest and the catalytic method can be used to extract the humic acid later.