Liquid chlorination leaching of secondary nickel anode mud

The nickel anode mud produced by a factory is smelted by fire method to produce an anode plate for secondary electrolysis and enrichment. The secondary electrolysis was carried out in a separate electrolysis system using an initial electrolyte containing 200 g/L of sulfuric acid at a cell voltage of 3 V and a current density of 250 A/m ² . During the process, the copper dissolved in the anode is precipitated on the copper cathode sheet, and after the nickel is dissolved, nickel sulfate is introduced into the solution. After about 7 days, a solution containing 90 g/L of nickel, 0.5 g/L of copper, and 10-15 g/L of free sulfuric acid can be produced and sent to obtain crystalline nickel sulfate. Copper cathode smelting copper anode plate.

Secondary output electrolytic nickel anode sludge containing a platinum group metal 0.15% to 0.2% of the total, according to the solid-liquid ratio 1:4 added 2.5 ~ 3mol / LHCl and 10% NaCl solution, was heated to 70 deg.] C Left and right, stirred and oxidized by chlorine gas, the produced 40% silver- containing slag is sent to the copper anode mud section for treatment.

After heating the chlorination solution to 80-90 ° C for 3 h, add copper wire for 2 to 3 hours. Output concentrate with 60g / L sulfuric acid leaching of copper removal HSR and then calcined at 600 ℃ selenium selenium dioxide was volatilized, the final precious metal concentrate containing platinum 40% to 50%. In order to obtain a relatively pure platinum concentrate, it is also possible to reduce the gold with sulfur dioxide before the copper wire is replaced.