SU384431A1 - Cadmium refining method - Google Patents

Description

(54) METHOD OF CADMY REFINEMENT

one

The invention concerns a cadmium amalgam refining process by successive electrolytic reprecipitation of cadmium from amalgam.

There is a method for refining cadmium in a four-second. electrolyzer with bipolar and gapym electrodes with sequential, epsi trolithic reprecipitation, cadmium J, at that. The refined ironics in the first section are carried out in ammonium non-chloronic acid and in the third. - in chlorine solutions.

This method does not produce high purity cadmium. In addition, after refining, cadmium is released in the form of a bulky, spongy sediment.

The peculiarity of the proposed method is that the refining in the second section is carried out in a bromide electrolyte containing 100-200 g / l of cadmium bromide 150/200 g / l of sodium bromide and 100-5Og / l of hydrobromic acid, the refining in the fourth section is in chloride-chloric acid electrolyte containing. 5O-7O g / l cadmium, 5O-35 g / p hydrochloric acid and 5O-100 g / l perchloric acid, and

during refining, the current density is maintained at 200–1000 a / m.

This method allows to obtain high purity in the form of large crystalline dendrites.

The drawing shows the installation diagram of the proposed method, which can be four times by using the electrochemical electrochemical deposition of cadmles in sec- ons of the electrolyzer. High purity cadmium in the fourth section in chlorine chlorides:;:: lectrite at the ends of the cathode gas: pin in the form of a co-crystalline de; g:}; com, Content: not mercury in refined: c1C) m. cad - s.- is (2-4) 1O%. The separation of mercury from cadmium is carried out by electrolyte in mixed form. loridna-chloroacidic electrolyte. High-purity cadmium dendrites are pressed into plexiglass molds, melted in electric furnaces in a reducing atmosphere, and poured into molds of spectrally pure graphite.

Chemical-spectral analysis of cadmium, screened by the amalgam method, shows that the resulting chemical meets the requirements of the technical conditions imposed on cd brand KD-LLC, and the total content of impurities in the refining process is reduced by 750–1000 times with analysis of 18 elements with Meceii and is (5-7) - 10%, which corresponds to the conditional content of the base metal is not. 99.99993%.

PRI me R. (Amalgamic refining cadmium mart {1-). Refining is carried out in four; .. iui ;; oiajOM electrolyzer made of plexiglass. In a thoroughly washed electrolyzer, mercury of VIEBES purity is charged: 6 O kg of space for the anode and bipolar electrodes. Metal cadmium grade KD-0 is taken in the form of granules, dissolved in a mercury anode at the rate of 5-7 Bes.% Cadmium amalgam. Electrodes containing 4.55 wt.% Cadmium are saturated by sequential electrolysis in sec in the corresponding electrolytes. Ammonium chloro acid solution of the first section contains, g / l: Cd () 100, 100, carried 0 100; The bromide solution of the second section contains, g / l: Cdbr. 100-200, Haber 150-200, HBr 100-50; The chloride solution of the third section contains, g / l: CdCGj 100-250, it contains 70-35 chloride chloride solution of the fourth section.

g / l: C 50-70, HCE 50-35 and HSEO 50100.

The electrolytes of all four sections are cadmium free by sequential electrolysis. The current density on both the anodic and cathodic sides of the bipolar electrodes is 2OO-1000 a / m and the temperature of the electrolytes does not exceed 40 ° C.

Claims (1)

Invention Formula The method of refining cadmium in four sections. an electrolyzer with bipolar amalgam electrodes by successive electrolytic reprecipitation of cadmium, the refining in the first section is carried out in ammonium chloric acid, and in the third section in chloride solutions, in order to increase the purity of cadmium and obtain it in the form of coarse crystal dendrites carried out in a solution containing 100–200 g / l of cadmium bromide, 15O – 2OO g / l of sodium bromide and 1OO – 5O g / l of hydrobromic acid; refining in the fourth section is in a solution containing 50- 70 g / l of cadmium, 50-35 g / l of hydrochloric acid and 50-1OO g / l of perchloric acid, and the current density during the refining process maintains 20O-1OOO a / m.