高铁酸钾的电化学制备

发布时间：2018-06-04 20:20

  本文选题：高铁酸钾 + 电解法　； 参考：《上海应用技术学院》2015年硕士论文

【摘要】：高铁酸钾(K2Fe04),以其超高的氧化价,还原产物的无毒性,自一出世就受到化学家的广泛关注。K2FeO4具有很强的氧化性,溶于水中能释放大量的原子氧,从而非常有效地杀灭水中的病菌和病毒。与此同时,自身被还原成新生态的Fe(OH)3。这是一种品质优良的无机絮凝剂,能高效地除去水中的微细悬浮物。高铁酸钾作为新型、绿色、环保氧化剂,在众多领域具有十分诱人的应用前景。目前高铁酸钾的制备方法主要有次氯酸盐氧化法,高温过氧化法,电解法。电解法由于操作简单,对设备的要求低,环境友好,且产物中的杂质种类少等优点而广受关注。理论上,电解法是最有希望进行工业化生产的制备方法,但工业化生产尚未展开,主要因为电解法得到产品浓度低,后续提纯困难；电解反应的电流效率低,耗能大；且高铁酸钾稳定性差,难以储存运输。本文主要研究的集中于探讨电解法制备高铁酸钾的各个影响因素。在以细铁丝网为阳极材料,在电流密度为100mA/cm2下进行电解,可在较大的电流密度下电解较短时间内,得到浓度较高,纯度较大的高铁酸钾产品。为得到最佳的电解制备工艺,研究了电解液组成、电解体系温度、阳极电流密度、电解时间、添加剂等工艺条件对电解制备高铁酸钾的电流效率的影响。从实验结果得出：温度的升高能显著提高电解过程的电流效率；当以16mol/L的KOH溶液作为电解质时,高铁酸钾的生成效率明显高于其他浓度；在电解过程中采用大电流密度能够短时间内有效积累高铁酸钾产品；产物浓度在2h左右达到最大。实验结果表明：以16mol/LKOH为电解质,阳极电流密度100mA/cm2,电解体系温度60℃,电解2h为电解过程的最佳工艺条件。在过电解液中加入NaSiO3:KI:KBr比例为1：1：1的添加剂时,能提高电解的电流效率。对回收的电解液进行了循环使用的可行性研究。经过过滤,补充氢氧化钾固体后,回收的电解液可重新投入生产,达到绿色化学的目的。电解得到的固体高铁酸钾应立即过滤或离心分离,并及时脱水脱碱才能保证高铁酸钾的稳定性。粗产品通过重结晶,脱水,脱碱后,产品纯度能达到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，

本文编号：1978704