20 kg capacity silver refining machine

silver refining process

(1) Cast silver anode plate: the silver electrolysis process requires casting coarse silver into an anode plate, and inserting the cast silver anode plate into the silver automatic electrolysis equipment for subsequent electrolysis. Therefore, the process of casting anode plate must be carried out before the raw crude silver enters the electrolytic process.

(2) Preparation of silver electrolyte and recovery of waste electrolyte: the process of manufacturing silver nitrate solution and mixing silver and nitric acid in water is called liquid making. The liquid can be prepared by reacting pure silver with nitric acid. The reaction equation of silver and nitric acid is as follows:

Ag+2HNO3→AgNO3+NO2↑+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 generated silver chloride precipitation is returned to the silver precipitation barrel for silver precipitation, and the coarse silver obtained after filtration is melted, cast and electrolyzed.

(3) Silver electrolysis: clean the surface of anode rod, conductive bar and electrolytic hook, put it into anode plate, and then adjust the current and voltage of silver electrolysis unit to the specified value, and then start the automatic scraper system. During the electrolysis process, only one person needs to stop to inspect whether the electrolysis is normal.

Figure 3 silver electrolysis equipment

(4) Cleaning and drying: the electrolytic silver is scraped out by the automatic scraper system. After electrolysis, open the discharge valve to clean and dry the produced silver powder and cast it into the required silver ingot.

(5) Purifying electrolyte: slowly stir and add NaOH into the waste electrolyte or silver containing waste liquid in the silver precipitation barrel, adjust the pH, filter, and the obtained silver oxide is used for standby. The waste liquid is treated. Add waste electrolyte into the electrolyte purification kettle, then stir slowly, add Ag2O, adjust the pH of the electrolyte, and take samples for several times to observe the electrolyte until the electrolyte becomes colorless and transparent. Finally, HNO3 is added, the pH is adjusted to the original pH, and filtered to obtain silver nitrate solution.

(6) Anode slime treatment: add nitric acid to the anode slime, which can dissolve other metals in the anode slime except gold, and then add NaCl to the solution. Silver nitrate reacts with NaCl to form AgCl precipitation. Add iron powder to the precipitation to replace coarse silver, and then take the coarse silver to melt and cast the anode plate.

一,设备清单

Wuxi Gremet Machinery has its own production workshop of  8000 square meters and 47 employees. The company The company specializes in smelting, refining and environmental protection of precious metals (gold, silver, platinum, palladium and rhodium), equipment development, technology promotion, production process design and workshop design, general contracting of precious metal refining projects, general contracting of laboratory construction projects, guiding trial production, etc.

Our main products are: high current density silver electrolysis unit, high current density gold electrolysis unit, cyclone electrowinning unit, platinum, palladium and rhodium refining and purification production system equipment, medium frequency furnace, high frequency furnace, gold and silver ingot vacuum ingot casting machine, bead spreader, gold wet refining process equipment, gold mud controlled electrochlorination production system equipment, polypropylene storage tank, flue gas absorption tower Nitrogen oxide flue gas treatment system equipment, gold smelting mould, fire assay ash dish, lead skin for laboratory, special reagent for rhodium refining.
The products authorized for distribution include: titanium reactor, glass reactor, enamel reactor, electrolytic rectifier power supply, glass condenser, chiller, oil press, laser marking machine, steam generator, aluminum tank, anti-corrosion pump valve, hardware electromechanical and other alchemy rooms and common equipment in rare and expensive factories.

Undertake the construction projects of alchemy room, rare and expensive plant and laboratory.

The company has a number of business backbones with rich production experience, who have served as chief engineer, deputy general manager of production, factory director, workshop director and team leader of precious metal smelting and refining enterprises respectively, and can provide the owner with a full set of technical services from factory design, production of non-standard equipment, agency procurement of standard equipment, installation and commissioning, and guiding on-site operation. He has successfully completed the "turnkey" EPC business for many times. So far, the company has successfully completed the construction project of gold and silver refining workshop of more than dozens of enterprises in the industry. Among the enterprises we have cooperated with, 13 gold refining enterprises have obtained the qualification of "providing standard gold ingots" in Shanghai gold exchange, which reflects the company's high technical level and good service quality.
In terms of precious metal refining technology and equipment, environmental protection technology and equipment, the company has 29 authorized patents, 2 pending invention patents and 13 utility model patents. The company was rated as a science and technology enterprise in 2017, a high-tech enterprise in 2018, a member of Environmental Protection Association in 2019 and passed the intellectual property management system certification. In December 2019, the high concentration NOx waste gas treatment device independently developed by our company was recognized as a scientific and technological achievement through the Department of science and technology.

And In Span, Czech, India, North Korea, Uzbekistan，Iran, Tajikistan，Mongolia, Cambodia, Laos, Vietnam, Indonesia, Myanmar, Senegal, Ghana, Ecuador。

We have experience for overses installation and commissioing.