【摘要】 本文通过物化分析和统计结构分析方法,考察了风化烟煤、褐煤和亚炭稀硝酸轻度氧解前后HA 和NHA 的官能团与分子结构特征的变化。结果表明,硝酸氧解均使煤结构中羧基和醒基明显增加。对于风化烟煤只发生脂肪侧链和部分芳碳的氧化脱氢反应,而对褐煤则氧解程度较深,以至芳核开环。前者生成的NHA 弱羧基较多,pK 值较低,后者的NHA 则与土壤中HA 的结构特征相似。对不同煤种的氧化-硝化反应过程也作了初步探讨。更多还原

【Abstract】 The humic acid of raw coal and the nitrohumic acid after dilute ni-tric acid oxidation from weathered coal,brown coal and lignite are stu-died by the chemical and electrochemical methods,IR-spectra,~1H-NMR,molecular weight determination,DTG,DTA and statistical structure analysis.A hypothetical model of the average structural units is propos-ed therefrom.The dilute nitric acid oxidation of coals causes the increasing of car-boxylic and quinone groups.For NHA of Lingshi weathered coal,the degree of ring condensation is higher,the content of substituable aroma-tic hydrogen is lower,the earboxylic groups is more and the pK value is lower than those of Huangxian brown coal.This indicates that the for-mer has higher cation exchange capacity.The NHA of either brown coal or lignite is similar to that of soil.Finally the mechanisms of the nitro-oxidation and nitration of HA from different coals are also discussed.更多还原