Preparation Of Ferrate (vi) And Its Fe (vi) Conversion Of Fe (iv)

The ferrate is the oxo acid salt of Fe(Ⅵ).It has the extremely strong oxidizing power. The ferrate can be used as the oxidant of the organic synthesis for its very high selectivity; as the watertreament agents because it has the excellent purification, disinfection, decolourization functions, and the second pollution can't be caused; as electrode material of "green"battery because of its high discharged capability and discharged voltage. But in the course of preparing, his producing rate is relatively lower, so it is not apply on a large scale in reality. Basis on the traditional classical hypochlorite oxidation process, make helpful improvement to experiment course , optimize laboratory conditions of preparing ferrate(Ⅵ), improve the producing rate of ferrate. This has positive meanings to practical application of ferrate(Ⅵ).First, compared with the Ferrate(Ⅵ) preparation method only through oxidation by hypochlorite, when the system is under radiation with CO2 laser which provides10.6 μ m, 10W infrared ray, the reaction rate can be accelerated, productive rate of FeO42- increment of 20%-30%, with the maximum concentration of FeO42- 0.22mol/L; and we analyze the basic principle of the reaction system which lie in the laser illumination, explain the theory reason accord with experimental result.Second, the traditional oxidation process is that Fe(Ⅲ) compound is put into the high-alkali solution of sodium hypochlorite and produces the ferrate(Ⅵ) solution. In this article ,ferric chloride is converted into potassium fluoferrite and produce the ferrate(Ⅵ) solution. The results are that the productive rate will obviously be improved ,the stability is strengthened. The best conditions are: Ferric chloride and potassium fluoride was mixed in a mole ratio of 1:9 to produce potassium fluoferrite, which was put into the high-alkali solution of sodium hypochlorite at constant temperature 45 ℃ for 90min,the product concentration of Ferrate(Ⅵ)solution can reach about 0.2mol/L.Third, The ferrate solution has the instability, people usually think that the ferrate would resolve and product Fe3+ or Fe(OH)3 automatically in the sour, alkaline conditions. This work traced the different concentration alkaline solution which included ClO- and no ClO- by the visual spectrum method, we studied the change process of ferrate(Ⅵ) and found while the Fe(Ⅵ) converse the Fe( OH)3, there still product the green solution of Fe(Ⅵ), the essential condition ofthe reaction is that [OH-]≥ 6mol/L. ClO- will make conversion rate fall and production concentration rise in the solution. Fe(Ⅳ) solution can exist in solution but can not decompose. This offers a new understanding for the decomposition conversion of ferrate(Ⅵ) in the solution.Finally, in the base cognition of the Fe(Ⅳ) solution' property , we study the production of Fe(Ⅳ) solution, and make sure the production conditions.