H_2O_2氧解褐煤产腐植酸的试验研究

[目的]探讨H2O2氧解褐煤产腐植酸的最佳工艺条件。[方法]采用H2O2降解云南曲靖褐煤制备黄腐酸,提取了褐煤及氧化残煤中的腐植酸,并利用pH分级法分出主要组分,对褐煤降解前后所提取的腐植酸进行了化学组成分析。[结果]对黄腐酸产率影响最大的因素是煤与氧化剂质量比,其次是氧化降解温度,H2O2浓度影响最小。优化工艺条件为:煤与H2O2质量比1∶0.60,氧化降解温度45℃,氧化降解时间210 min,H2O2浓度为20%。在最佳工艺条件下,黄腐酸的产率达20.40%。腐植酸官能团含量分析及红外光谱结果表明,降解产物黄腐酸中总酸性基团、羧基含量显著提高;OHA中的活性官能团含量及主要组分的沉淀酸度都较HA中的高。[结论]该研究为褐煤制备优质腐植酸提供了一种新的方法。

Experimental Study on the Production of Humic Acids from Brown Coal Using Hydrogen Peroxide

[Objective] The study aimed to discuss the optimal conditions of producing humic acids from brown coal using hydrogen peroxide.[Method] Fulvic acid(FA) was prepared by using the brown coal from Qujing,Yunnan Province,and humic acids were extracted from the original brown coal and its residues respectively,then the dominate constituents of humic acids were obtained by using pH grading method,finally their chemical compositions were characterized by Fourier transform infrared spectrometry and functional group content.[Result] Coal-oxidant ratio affected the yield of FA most obviously,followed by oxidization temperature,and oxidant concentration had no obvious effect.The optimum conditions were determined as follows:coal-oxidant ratio was 1∶ 0.60,oxidization temperature was 45 ℃,oxidization duration was 210 min,and the concentration of hydrogen peroxide was 15%.Under the conditions,the yield of FA was up to 20.40%.Analysis of component properties indicated that the content of carboxyl and total acidic group in FA was improved obviously,and the content of active functional groups in OHA was higher than that of HA,while the dominate constituents of OHA during precipitation needed higher pH compared with those of HA.[Conclusion] The research provided a new method to prepare good humic acids using brown coal.