煤泥氧化制備腐植酸的實(shí)驗(yàn)研究
發(fā)布時(shí)間:2018-05-02 09:09
本文選題:煤泥 + 氧化 ; 參考:《西安科技大學(xué)》2015年碩士論文
【摘要】:隨著原煤入選量的提高,煤泥的產(chǎn)量也在增大。目前主要是電廠燃燒或露天堆放,這不僅對環(huán)境造成了污染,而且是資源的浪費(fèi)。利用煤泥制備腐植酸,解決煤泥利用單一的問題同時(shí)也提高了其經(jīng)濟(jì)價(jià)值。本課題研究黃陵煤泥氧化制備腐植酸。首先通過酸洗除掉煤泥中金屬離子,測定預(yù)處理后鹽酸溶液中金屬離子的量,確定最佳鹽酸溶液的pH值;然后再進(jìn)行空氣加熱和H_2O_2氧化,滴定法測定氧化后煤泥中腐植酸的含量,確定最佳氧化方式;最后,通過NaOH提取氧化煤泥中腐植酸,加入鹽酸或強(qiáng)酸型陽離子交換樹脂進(jìn)行酸析獲得腐植酸產(chǎn)品。在煤泥預(yù)處理實(shí)驗(yàn)中,pH值1的鹽酸溶液處理效果較好,可以除掉煤泥中大約3%的金屬離子(Fe、Al、Mg、Ca)。在煤泥的氧化實(shí)驗(yàn)中,采用兩種方式對其進(jìn)行氧化,一是空氣中加熱氧化,氧化溫度310℃,氧化時(shí)間6h,煤泥中腐植酸總量為34.64%;二是H_2O_2氧化,用30%H_2O_2氧化煤泥,氧化溫度40℃,氧化時(shí)間48h,煤泥中腐植酸總量為2.21%。明顯空氣中加熱氧化較好。以黃陵煤泥為原料,堿溶酸沉法制備腐植酸實(shí)驗(yàn)中,通過單因素實(shí)驗(yàn),研究了氧化溫度、氧化時(shí)間、堿液濃度、固液比、反應(yīng)時(shí)間、反應(yīng)溫度、酸析pH對腐植酸產(chǎn)率的影響;通過正交試驗(yàn)確定最優(yōu)條件。制備腐植酸的優(yōu)化工藝條件為氧化溫度310℃,氧化時(shí)間6h,堿液濃度1.5%,風(fēng)化煤和堿液的固液比1:25,反應(yīng)溫度95℃,反應(yīng)時(shí)間2h,酸化pH值1.5,腐植酸產(chǎn)率為26.84%。正交試驗(yàn)中,影響腐植酸的產(chǎn)率因素排序依次為:堿液濃度、氧化時(shí)間、氧化溫度、提取溫度、提取時(shí)間。堿溶-強(qiáng)酸型陽離子交換樹脂制備腐植酸實(shí)驗(yàn)中,最優(yōu)條件下腐植酸產(chǎn)率為24.37%。通過紅外光譜、紫外光譜分析確定制備產(chǎn)品為腐植酸,再將其進(jìn)行成份分離,結(jié)果表明制備的腐植酸中黑腐酸含量達(dá)到95%以上。堿溶酸沉法制備的腐植酸的純度為85.4%,總酸性為7.761mmol/g羧基含量為5.625mmol/g羥基含量為2.136mmol/g,灰分含量為4.56%;堿溶-強(qiáng)酸型陽離子交換樹脂法制備的腐植酸純度為92.54%,總酸性為8.013mmol/g,羧基含量為5.804mmol/g,羥基含量為2.209mmol/g,灰分含量為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,
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