煤泥氧化制备腐植酸的实验研究

发布时间：2018-05-02 09:09

  本文选题：煤泥 + 氧化　； 参考：《西安科技大学》2015年硕士论文

【摘要】：随着原煤入选量的提高,煤泥的产量也在增大。目前主要是电厂燃烧或露天堆放,这不仅对环境造成了污染,而且是资源的浪费。利用煤泥制备腐植酸,解决煤泥利用单一的问题同时也提高了其经济价值。本课题研究黄陵煤泥氧化制备腐植酸。首先通过酸洗除掉煤泥中金属离子,测定预处理后盐酸溶液中金属离子的量,确定最佳盐酸溶液的pH值;然后再进行空气加热和H_2O_2氧化,滴定法测定氧化后煤泥中腐植酸的含量,确定最佳氧化方式;最后,通过NaOH提取氧化煤泥中腐植酸,加入盐酸或强酸型阳离子交换树脂进行酸析获得腐植酸产品。在煤泥预处理实验中,pH值1的盐酸溶液处理效果较好,可以除掉煤泥中大约3%的金属离子(Fe、Al、Mg、Ca)。在煤泥的氧化实验中,采用两种方式对其进行氧化,一是空气中加热氧化,氧化温度310℃,氧化时间6h,煤泥中腐植酸总量为34.64%;二是H_2O_2氧化,用30%H_2O_2氧化煤泥,氧化温度40℃,氧化时间48h,煤泥中腐植酸总量为2.21%。明显空气中加热氧化较好。以黄陵煤泥为原料,碱溶酸沉法制备腐植酸实验中,通过单因素实验,研究了氧化温度、氧化时间、碱液浓度、固液比、反应时间、反应温度、酸析pH对腐植酸产率的影响;通过正交试验确定最优条件。制备腐植酸的优化工艺条件为氧化温度310℃,氧化时间6h,碱液浓度1.5%,风化煤和碱液的固液比1:25,反应温度95℃,反应时间2h,酸化pH值1.5,腐植酸产率为26.84%。正交试验中,影响腐植酸的产率因素排序依次为:碱液浓度、氧化时间、氧化温度、提取温度、提取时间。碱溶-强酸型阳离子交换树脂制备腐植酸实验中,最优条件下腐植酸产率为24.37%。通过红外光谱、紫外光谱分析确定制备产品为腐植酸,再将其进行成份分离,结果表明制备的腐植酸中黑腐酸含量达到95%以上。碱溶酸沉法制备的腐植酸的纯度为85.4%,总酸性为7.761mmol/g羧基含量为5.625mmol/g羟基含量为2.136mmol/g,灰分含量为4.56%;碱溶-强酸型阳离子交换树脂法制备的腐植酸纯度为92.54%,总酸性为8.013mmol/g,羧基含量为5.804mmol/g,羟基含量为2.209mmol/g,灰分含量为2.44%。
[Abstract]:With the increase of raw coal content, the output of coal slime is also increasing. At present, power plant combustion or open-air stacking, which not only pollutes the environment, but also a waste of resources. The preparation of humic acid from coal slime solves the problem of single utilization of slime and improves its economic value. The preparation of humic acid by oxidation of Huangling coal slime was studied in this paper. First, the metal ions in the coal slime were removed by acid washing, the amount of metal ions in the hydrochloric acid solution was determined after pretreatment, the pH value of the best hydrochloric acid solution was determined, and then the air was heated and H_2O_2 oxidized. The content of humic acid in the oxidized slime was determined by titration, and the best oxidation method was determined. Finally, humic acid was extracted from oxidized slime by NaOH, and the humic acid product was obtained by adding hydrochloric acid or strong acid cationic exchange resin. In the coal slime pretreatment experiment, the hydrochloric acid solution with pH value 1 has a good treatment effect, and about 3% of the metal ions in the slime can be removed. In the oxidation experiment of coal slime, it is oxidized in two ways, one is heated oxidation in air, the oxidation temperature is 310 鈩，

本文编号：1833276