Gold ore desorption electrolysis process and equipment

In the process of gold ore dressing, desorption electrolysis is a key process step for extracting gold from gold-loaded carbon, which plays a vital role in improving the recovery rate of gold and ensuring the efficient utilization of gold mine resources. It is specially used to extract gold from gold-loaded carbon adsorbed with gold cyanide complex. This process uses high temperature and high pressure environment to promote the separation of gold from gold-loaded carbon and deposit and recover it in the subsequent electrolysis link. It is a key node to realize the transformation of gold from complex ore system to high-purity product. Let's learn about gold ore desorption electrolysis process together.

Regarding desorption electrolysis, we divide it into two parts: analysis and electrolysis for detailed introduction.

Desorption of gold

The desorption of gold is to put the gold-loaded carbon into the analysis solution to make the gold desorb from the carbon surface into the solution. The process is to use chemical reaction to desorb gold from the gold-loaded carbon.

1. Principle of gold ore desorption

The principle is that in the early stage of gold ore beneficiation, activated carbon, due to its huge specific surface area and special pore structure, shows a strong adsorption capacity for gold-cyanide complex [Au(CN)^₂⁻], thereby achieving the enrichment of gold on gold-loaded carbon. Under temperature and high pressure conditions, anions that are easily adsorbed by activated carbon are added to the mixed system of gold-loaded carbon and desorption liquid. These anions can compete with the gold-cyanide complex for adsorption sites on the surface of activated carbon with stronger adsorption affinity, and then displace [Au(CN)^₂⁻] from the gold-loaded carbon, allowing it to re-enter the solution and complete the gold desorption process.

2. Gold desorption equipment

Analysis tower: used to accommodate the analysis solution and gold-loaded carbon, provide sufficient contact time to ensure the analysis effect, have good sealing performance and thermal insulation performance, and are usually equipped with a stirring device inside to promote the full mixing of gold-loaded carbon and desorption liquid and improve the desorption efficiency.

Heating system: Provides the required high temperature environment. The heating device is connected to the temperature control system and can accurately adjust the temperature in the desorption tank and electrolytic cell according to the process requirements.

Stirring system: Ensures sufficient mixing between the analytical solution and the gold-loaded carbon to improve the analytical efficiency.

3. Common reagents for gold desorption

High temperature and high pressure analysis: Use a mixed solution of NaCN and NaOH to analyze gold under high temperature and high pressure conditions. This method is efficient, but energy consumption is large.

Zadra method: Use low concentration NaCN and NaOH solutions to analyze gold at room temperature and pressure. Although the efficiency is slightly lower, the operation is simple and the cost is low.

AARL method: Use high concentration NaCN and NaOH solutions and add ethanol as an auxiliary agent to improve the analytical efficiency. This method is suitable for processing high-grade gold-loaded carbon.

Inco method: Use a mixed solution of copper sulfate and sulfuric acid for analysis, which is suitable for certain specific types of gold-loaded carbon.

Electrolysis of gold

The electrolysis of gold is to pass the analyzed gold-containing solution through the electrolytic cell, and reduce the gold ions to metallic gold under the action of current and deposit them on the cathode.

1. Principle of gold electrolysis

The principle is to build an electric field at the positive and negative poles through an external DC power supply. When the current passes through the precious liquid, the ions in the solution move in a directional manner, [Au(CN)₂⁻] migrates to the anode under the action of the electric field, and other cations migrate to the cathode. On the cathode surface, a reduction reaction occurs, and the gold ions in [Au(CN)₂⁻] gain electrons and are reduced to metallic gold atoms, which are then deposited on the cathode surface. As the electrolysis continues, gold atoms continue to accumulate at the cathode, eventually forming a gold layer with a certain thickness and purity, realizing the transformation and recovery of gold from the solution phase to the solid phase.

2. Gold electrolysis equipment

Electrolytic cell: The electrolytic cell is the main equipment in the electrolysis process, consisting of a fixed part, a moving part, a cathode and an anode. The fixed part and the moving part are made of carbon steel and are equipped with a non-detachable insulation cover with good corrosion resistance.

Anode: Insoluble materials such as lead plates or titanium plates are usually used to prevent the anode material from dissolving into the solution.

Cathode: Stainless steel plate or titanium plate is often used as cathode, and a layer of silver can be plated on the surface to improve conductivity and gold deposition efficiency.

Power supply: Provide DC power supply, and the current intensity is adjusted according to the design and production requirements of the electrolytic cell.

Pressure control device: including safety valve, pressure sensor, pressure regulating valve, etc., which can monitor the system pressure in real time, and stabilize the pressure within the set range by adjusting the intake or exhaust volume to ensure the safe operation of the equipment.

The above is an introduction to the gold mine desorption electrolysis process and related equipment. In the actual ore dressing plant, how to use desorption electrolysis or whether desorption electrolysis is needed depends on the properties of the gold ore. Therefore, it is necessary to conduct ore dressing test analysis first, and then design a suitable gold mine gold extraction technology based on the actual situation to obtain an ideal gold recovery rate.