Potassium ferrate preparation method

Abstract

The invention discloses a process for preparing potassium ferrate. An electrolysis bath is placed inside a water bath kettle with a constant temperature of 15-35DEG C, white cast-iron is placed inside a second groove of an anode chamber of the electrolysis bath, nickel screens as negative electrodes are placed inside a first groove and a third groove, electrolytic solution is NaOH of 14mol per liter, and N2 is sent into the cathode chamber to take off hydrogen. KIO4 of 0.1% and NaCl of 3% are added in the cathode chamber, direct current of 6-7mA per square centimeter is applied for reaction of 2-10 hours, sodium ferrate is prepared via electrolysis, then potassium ferrate solution in the second groove is concentrated via electro-osmosis method between the first groove and the second groove, after 5-10 hours the potassium ferrate solution in the second groove is taken out and added with KOH solid to be stirred for dissolving, after the mixture stands for aging, crude products of the potassium ferrate are obtained via extraction and filtration, and finally the potassium ferrate with high purity is obtained via recrystallization. The invention is simple in preparing process and is pollution-free, and the degree of purity of the prepared potassium ferrate products reaches up to 98%.

Description

technical field [0001] The present invention relates to a kind of iron compound, more particularly to a kind of preparation method of potassium ferrate which can be used as battery material. Background technique [0002] Ferrate is a salt composed of hexavalent ferrate and metal ions, and its general formula is M x FeO 4 . In 1999, Israeli scientist Licht Stuart and others proposed that ferrate can be used as a positive electrode active material, and invented a super-iron battery. The preparation method of ferrate is mainly divided into chemical method and electrochemical method, and chemical method can be divided into hypochlorite oxidation method and peroxide oxidation method. The hypochlorite oxidation method is to use iron salt to generate ferric hydroxide in an alkaline solution, and then use sodium hypochlorite to oxidize Fe. 3+ Oxidize into sodium ferrate, remove the precipitate, add excess potassium hydroxide, and then separate, wash, purify and dry to obtain the...

AI Technical Summary

Problems solved by technology

However, the requirements for the material of the electrolytic cell and diaphragm are relatively high. Metal iron is easily passivated at the anode, sodium ferrate is unstable, and factors such as current density, electrolysis temperature, and electrolysis time will affect the current efficiency.

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