Electrochemical dissolving method for noble metal

[0027] Take a platinum sheet with a thickness of 0.5-1mm, cut it into 125mm×30mm (weight 20g) as an electrode, put it into a beaker filled with 200ml 12NHCl to form an electrolytic cell. An alternating current of 6.5 volts and 25 A was applied to the electrolytic cell. After passing through the current, pass cooling water around the beaker to control the temperature of the electrolytic cell at 25°C. A large number of tiny bubbles are generated on the electrode surface, and the color of hydrochloric acid gradually turns yellow, from light to dark. After 3 hours, the platinum electrode was taken out, washed, dried, and weighed. A total of 9.72 grams of platinum was dissolved. The dissolution rate of platinum is 0.060 g Pt / cm 2 .Hour.

[0031] Replace the beaker with a φ15mm U-shaped tube, apply an alternating current of 60 volts and 4.6 amps to the electrolytic cell, and stop the reaction after 3 hours. The dissolution rate of platinum is 0.0015g Pt / cm 2 .Hour.

[0033] Except changing the concentration of hydrochloric acid, other conditions are the same as in Example 1, and the test results are listed in Table 1.

[0034] Hydrochloric acid concentration

[0035] The results in Table 1 show that the higher the concentration of hydrochloric acid, the higher the dissolution rate of metal Pt.