SU36412A1 - The method of cleaning solutions of nickel salts - Google Patents

Description

According to the proposed method of purifying solutions of nickel salts, nickel oxide hydrate or a mixture of this hydrate with nickel oxide is used as an active oxidant of iron. Nickel oxide hydrate, due to the enormous active surface, very rapidly oxidizes iron and at the same time neutralizes the solution being purified, is a precipitator for hydroxides. In addition, nickel oxide hydrate has the advantage of other precipitators (nickel oxide hydrate, etc.), in the sense that cobalt in the form of hydroxide precipitates out of solution simultaneously with iron.

To precipitate iron, hydrated oxide hydrate is applied in water in the form of a thick but free flowing pulp. The latter is introduced in small portions into the solution, first before the oxidation of iron, and then until the solution is completely neutralized by heating to 70-80 ° C and continuously stirring with air. Iron hydroxide precipitates first, and with prolonged heating and addition, an excess of nickel oxide hydrate cobalt precipitates, as well as copper, if its content in the solution is small.

-svb.:. J.; -

Nickel oxide hydrate is obtained by electrolytic oxidation of nitrous oxide hydrate obtained by chemical njrreM or by the known method of electrolysis of nickel matte.

In the latter case, the anodes of Feinstein (or black nickel) with a low content of iron (up to 0) and copper (up to 0,) are subjected to electrolysis in a 20 / ohm solution of sodium chloride.

The electrolysis, with continuous mixing with air, continues until the nickel content in the hydrate pulp that forms reaches 50 g per 1 liter. The hydrate pulp is transferred to another oxidation bath. The oxidative bath (coal) is located horizontally at the bottom of the bath. The cathode of iron or nickel wire mesh is located above the anode.

The chlorine green nickel hydrate released at the anode chlorine is oxidized to black oxide hydroxide. The oxidation continues to the desired degree, depending on the content of iron and free acid in the solution being purified. The resulting precipitate of nickel oxide hydrate or (in the case of incomplete oxidation) a mixture of nitrates of oxide and oxide

It is filtered out and, depending on its further use, can be directly used in the process of electrolysis purification or should be: REMOVED from sodium chloride when purifying nickel solutions for the preparation of salts. The filtrate (sodium chloride solution), nov is used as an electrolyte. . :. ,

the subject of the invention ..

A method of purifying a solution of sodium salts, especially iron, with the latter being converted into an oxide compound, characterized in that nickel hydroxide or a mixture of hydrate with nickel oxide hydrate is introduced into the solutions.