Gold plating recovery method and process

Gold plating recovery method and process

Gold plating is a common metal processing technology that can coat the metal surface with a metal film, which can improve its appearance and texture, increase its corrosion resistance and wear resistance. In daily life, gold plating is widely used in jewelry, watches, decorations, and other fields. Due to the increase in usage time or other reasons, the gold plating layer may wear or peel off and need to be recycled.

Gold plating recycling is an important environmental protection task. By rationally selecting applicable methods and processes, metal resources can be effectively recycled and the impact on the environment can be reduced. Mechanical removal, chemical dissolution, and electrolysis are commonly used gold plating recycling methods. Each method has its applicable scenarios and operating steps. In practical applications, appropriate methods should be selected according to specific circumstances, and safe operating procedures should be followed to ensure the safety and effectiveness of the recycling process. Commonly used gold plating recycling methods and processes are:

Mechanical removal is a common gold-plated recycling method that removes the gold-plated layer on the metal surface through physical force. This method is suitable for gold-plated items with larger areas, such as metal ornaments, utensils, etc. The specific steps are as follows:

1. Preparation: First, prepare the required tools and equipment, such as sandpaper, grinding wheels, grinding heads, etc. At the same time, ensure that the operating environment is well ventilated to avoid the generation of harmful gases.

2. Surface grinding: Use fine sandpaper or grinding heads to gently grind the surface of the gold-plated object until the gold layer is completely removed. Pay attention to control the strength and angle to avoid damage to the object itself.

3. Polishing: After grinding, use a polishing machine or polishing cloth to polish the object to restore its gloss and smoothness. Polishing can remove scratches and roughness that may be generated during the grinding process.

4. Cleaning and maintenance: Then, rinse the object with clean water to ensure that the residue generated during the grinding and polishing process is removed. Subsequently, use a suitable metal care agent to maintain the object to extend its service life.

Chemical dissolution is a commonly used gold plating recovery method that uses chemical reactions to dissolve the gold layer and separate the metal. This method is suitable for the recovery of small gold-plated items and metal scraps. The specific steps are as follows:

1. Acidic dissolution: Select an appropriate acidic solution, such as nitric acid or hydrochloric acid, and soak the gold-plated items in it. The acidic solution can react with the gold layer to produce soluble gold salts.

2. Filtration separation: After the gold layer is dissolved, filter the solution to remove insoluble impurities and residual base metal. The filtrate will contain gold salts.

3. Reduction precipitation: Reduce the gold salt to metal precipitate by adding a reducing agent (such as sulfur dioxide) or electrochemical methods. The metal precipitate can be used for subsequent processing and purification.

4. Purification treatment: Purify the metal precipitate to remove other impurities and gold salt residues. Common purification methods include solvent extraction, electrolysis and distillation.

Electrolysis is an efficient gold plating recovery method that uses electrochemical reactions to separate the gold layer from the base metal. This method is suitable for items with small metal surface areas and require highly accurate control. The specific steps are as follows:

1. Construct an electrolytic cell: Prepare an electrolytic cell containing an appropriate electrolyte. The electrolyte can be a solution containing a gold salt.

2. Electrolysis operation: Xi'an Transformer Recycling Company said that the gold-plated item is used as the anode (the anode is the gold-plated layer) and placed in the electrolyte. At the same time, set a suitable cathode, usually a non-reactive material such as stainless steel.

3. Apply current: By connecting the power supply, applying appropriate current and voltage, the gold layer in the electrolyte is precipitated on the anode and pure metal is formed on the cathode.

4. Collect metal: Collect the precipitated metal for subsequent processing and purification.