Silver Electrolytic Refining Equipment

1. Casting silver anode plate: the silver electrolytic process requires that the coarse silver is cast into the anode plate, and the cast silver anode plate is inserted into the silver automatic electrolytic equipment for the subsequent electrolytic process. Therefore, before raw silver enters the electrolytic process, the anode plate casting process must be carried out.
2. Preparation of silver electrolyte and recovery of waste electrolyte: the process of making silver nitrate solution and mixing silver and nitric acid in water is called liquid making. The liquid can be prepared by reaction of pure silver with nitric acid. The reaction equation of silver and nitric acid is as follows:
Ag + 2 hno3 – > AgNO3 + NO2 write + H2O
When the impurity content of electrolyte is too high, sodium chloride is added to the waste electrolyte, and sodium chloride reacts with silver nitrate to form silver chloride precipitation. The resulting silver chloride is precipitated back into the silver bucket for silver precipitation, and the coarse silver obtained after filtration is carried out for melting and casting electrolysis.
3. Silver electrolysis: clean the anode rod, conductive bar, electrolytic hook surface, put in the anode plate, and then adjust the current and voltage of the silver electrolytic unit to the specified value, open the automatic scraping system, in the process of electrolysis only one person to check whether the electrolytic work is normal.
4. cleaning and drying: the electrolyzed silver is scraped out by the automatic scraper system. After the electrolyzation is finished, the material valve is opened to clean and dry the produced silver powder and cast into the required silver ingot.
5. Purifying electrolyte: Slowly stir NaOH into the waste electrolyte or silver-containing waste liquid in the silver bucket, adjust the pH, filter, obtain silver oxide reserve, waste liquid for waste liquid treatment. Add the waste electrolyte into the electrolyte purifying kettle, then slowly stir in Ag2O, adjust the pH of the electrolyte, and observe the electrolyte by sampling for several times until the
electrolyte becomes colorless and transparent. Finally, HNO3 is added to the solution, the pH is adjusted to the original pH, and the silver nitrate solution is obtained through filtration.
6. anode mud treatment: Add nitric acid to the anode mud, nitric acid can dissolve other metals except gold in the anode mud, then add NaCl to the solution, silver nitrate reaction with NaCl, generate AgCl precipitation, add iron powder to the precipitation, replace the coarse silver, and then take the coarse silver to melt cast anode plate.