發(fā)布時間：2018-06-04 20:20

  本文選題：高鐵酸鉀 + 電解法��； 參考：《上海應(yīng)用技術(shù)學(xué)院》2015年碩士論文

【摘要】：高鐵酸鉀(K2Fe04),以其超高的氧化價,還原產(chǎn)物的無毒性,自一出世就受到化學(xué)家的廣泛關(guān)注。K2FeO4具有很強(qiáng)的氧化性,溶于水中能釋放大量的原子氧,從而非常有效地殺滅水中的病菌和病毒。與此同時,自身被還原成新生態(tài)的Fe(OH)3。這是一種品質(zhì)優(yōu)良的無機(jī)絮凝劑,能高效地除去水中的微細(xì)懸浮物。高鐵酸鉀作為新型、綠色、環(huán)保氧化劑,在眾多領(lǐng)域具有十分誘人的應(yīng)用前景。目前高鐵酸鉀的制備方法主要有次氯酸鹽氧化法,高溫過氧化法,電解法。電解法由于操作簡單,對設(shè)備的要求低,環(huán)境友好,且產(chǎn)物中的雜質(zhì)種類少等優(yōu)點(diǎn)而廣受關(guān)注。理論上,電解法是最有希望進(jìn)行工業(yè)化生產(chǎn)的制備方法,但工業(yè)化生產(chǎn)尚未展開,主要因?yàn)殡娊夥ǖ玫疆a(chǎn)品濃度低,后續(xù)提純困難；電解反應(yīng)的電流效率低,耗能大；且高鐵酸鉀穩(wěn)定性差,難以儲存運(yùn)輸。本文主要研究的集中于探討電解法制備高鐵酸鉀的各個影響因素。在以細(xì)鐵絲網(wǎng)為陽極材料,在電流密度為100mA/cm2下進(jìn)行電解,可在較大的電流密度下電解較短時間內(nèi),得到濃度較高,純度較大的高鐵酸鉀產(chǎn)品。為得到最佳的電解制備工藝,研究了電解液組成、電解體系溫度、陽極電流密度、電解時間、添加劑等工藝條件對電解制備高鐵酸鉀的電流效率的影響。從實(shí)驗(yàn)結(jié)果得出：溫度的升高能顯著提高電解過程的電流效率；當(dāng)以16mol/L的KOH溶液作為電解質(zhì)時,高鐵酸鉀的生成效率明顯高于其他濃度；在電解過程中采用大電流密度能夠短時間內(nèi)有效積累高鐵酸鉀產(chǎn)品；產(chǎn)物濃度在2h左右達(dá)到最大。實(shí)驗(yàn)結(jié)果表明：以16mol/LKOH為電解質(zhì),陽極電流密度100mA/cm2,電解體系溫度60℃,電解2h為電解過程的最佳工藝條件。在過電解液中加入NaSiO3:KI:KBr比例為1：1：1的添加劑時,能提高電解的電流效率。對回收的電解液進(jìn)行了循環(huán)使用的可行性研究。經(jīng)過過濾,補(bǔ)充氫氧化鉀固體后,回收的電解液可重新投入生產(chǎn),達(dá)到綠色化學(xué)的目的。電解得到的固體高鐵酸鉀應(yīng)立即過濾或離心分離,并及時脫水脫堿才能保證高鐵酸鉀的穩(wěn)定性。粗產(chǎn)品通過重結(jié)晶,脫水,脫堿后,產(chǎn)品純度能達(dá)到95%。
[Abstract]:Potassium ferrate (K2Fe044), with its high oxidation valence and nontoxic reduction products, has been widely concerned by chemists since its birth. K2FeO4 is highly oxidizing and can release a large amount of atomic oxygen in water. This is very effective in killing bacteria and viruses in the water. At the same time, it was reduced to a new ecological Feo OH 3. This is an excellent inorganic flocculant, which can effectively remove fine suspended matter in water. As a new, green and environmentally friendly oxidant, potassium ferrate has a very attractive application prospect in many fields. At present, the main preparation methods of potassium ferrate are hypochlorite oxidation, high temperature peroxidation and electrolysis. Electrolysis has attracted much attention because of its advantages such as simple operation, low requirements for equipment, environmental friendliness, and few kinds of impurities in the products. In theory, electrolysis is the most promising preparation method for industrial production, but the industrial production has not been carried out, mainly because of the low concentration of the product obtained by electrolysis, the difficulty of subsequent purification, the low current efficiency of electrolytic reaction, and the large energy consumption. And potassium ferrate is difficult to store and transport because of its poor stability. In this paper, the main research focused on the preparation of potassium ferrate by electrolysis. When the thin wire mesh is used as anode material and the current density is 100mA/cm2, the potassium ferrate with high concentration and high purity can be obtained by electrolysis in a short time at higher current density. In order to obtain the best electrolytic preparation process, the effects of electrolyte composition, electrolytic system temperature, anode current density, electrolysis time and additives on the current efficiency of electrolytic preparation of potassium ferrate were studied. The experimental results show that the current efficiency of the electrolysis process can be significantly improved by increasing the temperature, and when the KOH solution of 16mol/L is used as the electrolyte, the formation efficiency of potassium ferrate is obviously higher than that of other concentration. The high current density can effectively accumulate potassium ferrate in a short period of time, and the concentration of the product reaches the maximum in about 2 hours. The experimental results show that the optimum process conditions are as follows: 16mol/LKOH as electrolyte, anode current density 100 Ma / cm ~ 2, electrolysis temperature 60 鈩，

本文編號：1978704