The Electrochemical Synthesis Of Potassium Ferrate

Potassium ferrate(VI)(K2FeO4) has a high oxidation state, and it is friendly to environment, so it becomes popular as soon as it appears the first time.K2FeO4 has a very good oxidizability, it releases much atom O when it solutes in the water. And it can kill the pathogenic bacteria and virus in the water efficiently. In the same time, itself will be revert to the new Fe(OH)3 which is a very good kind of inorganic flocculant, Fe(OH)3 can efficiently remove micro suspended solids in the water. As a new green environmental-friendly oxidation, potassium ferrate(VI) show a remark-able application prospect in many fields. In recent years, there are many researches about treating potassium ferrate(VI) as a kind of anode positive materia in a green power source, and it shows its priority in the electrochemical performance. Presently there is three production methods of potassium ferrate(VI), they are pypocholoride oxidation, thermal eroxidation, electrolysis. Electrolysis is most possible used to industy in theory, but in fact none is used in the factory, the main reason is the production concentration is very low and the production is hard to collect; besides potassium ferrate(VI) has a poor stability and hard to reserve and transport. In this paper, the study is focus on preparing K2FeO4 by means of eletrolysis.By using the thin iron gauze as working anode, we can get enough K2FeO4 product of high concentration and good purity in a comparatively short time by means of electrolyzing with a current density of 100mA/cm2.In order to achieve the best process of preparing K2FeO4 via electrolysis, I focus my study on the influence of electrolyte composition, system temperature, the current density of anode, electrolysis time and additives on the current efficiency of electrolysis. the experiment results showed:the rise of temperature is a remarkable way to increase the current efficiency; the current of preparing K2FeO2 is obviously higher than other concentration when taking 16mol/L KOH solution as the electrolyte; it is a efficient way to accumulate a big mount of K2FeO4 product in a short time by electrolyzing with a high current density; the concentration of K2FeO4 reaches the max after about 2h. From the experiment the best process of electrolysis are:16M KOH,100mA/cm2,60℃,2h. It is good for increasing the current efficiency when the additives propotion of Na2SiO3:KI. KBr is 1:1:1.The feasibility study of recycling used electrolyte is done to realize the aim of green chemisty by filtering the used electrolyte an adding new solid KOH, the used electrolyte can be put on production again. The K2FeO4 product which is get from electrolysis should immediately remove the water and alkaline in order to ensure the stability of K2FeO4.The purity of solid K2FeO4 can reach 95% after recrystallization, dehydration and dealkalization.