High-purity gold 99.999% is needed in industries such as semiconductors and healthcare, etc.
As the follow 3 steps, we could produce 99.999% Super Purity Gold by electrolysis process.
Step 1: Cast Gold to be Anodes
99.99 % gold is placed in a medium-frequency melting furnace (as shown in the figure) to smelt and cast into gold electrolytic anode plates. The maximum melting temperature of the medium-frequency furnace is 1600℃, and the melting time of a single furnace is 10 minutes. A crucible is used, along with a gold anode mold.
Stpe 2. Electrolyte Preparation
The gold electrolyte is prepared using a aqua regia gold dissolving reactor. Take 99.99% gold powder and add aqua regia to fully dissolve it. After dissolution, filter out the insoluble residue and add the solution to the electrolytic cell, diluting it to 150g/ L.
When the impurity ions in the electrolyte exceed the standard, the electrolyte needs to be replaced. When replacing the electrolyte, anhydrous sodium sulfite should be used to recover the gold in the waste electrolyte. The recycled gold powder is recast into anode plates and enters the gold electrolysis process.
Step 3. Electrolytic Refining
The cast gold (99.99% ) anode plates are hung into the electrolytic cell. The electrolyte is replenished to the circulating liquid level with a 2:1 hydrochloric acid solution to keep the solution stable. Then, the electrolysis is started and inspected regularly.
After the electrolysis is completed, the electrolysis is turned off, the cathode plates are removed, and the 99.999% Super Purity Gold precipitated on the cathode plates is washed off and collected for washing and drying.
WhatsApp us