Introduction to Aqua Regia
The aqua regia refining process is used to refine gold alloys using a combination of acids and chemical products. The aqua regia solution consists of a mixture of hydrochloric acid HCL and nitric acid HNO3.
The refining process can be broken down into several steps:
- Analysis of the gold to be refined
- Production of Au grains or thin strips
- Refining process
- Separation and recovery of the AgCl
- Precipitation of the gold
- Filter and rinsing of the gold powder
- Analysis of the refined gold
- Melting of the Au into final required form
- Very compact plant
- Easy handling
- Low operation costs
- No harmful fumes
- No gold losses
- Automatic acid loading
Refining using Aqua Regia
Best suited for gold with an initial purity of at least 600/1000. Initial purities below this value can reduce the production capacity as well as increase process times.
Recommended maximum silver content: 10-12 %. Percentages above these values can reduce production capacity as well as increase process times.
The gold should be either melted into fine grains – using a melting furnace and a grain tank – or very thin strips.
Strips are ideal due to their large surface area and complete dissolution when emerged in the aqua regia solution.
Grains, due to their irregular shape and size, are more difficult to dissolve and often leave leftovers in the reactor. On the other hand, they are quicker to produce than strips.
- Anti-acid polypropylene hood containing all the necessary equipment. Designed to recover acid losses
- Electric heater with potentiometer
- Pyrex reactor with fume condenser
- Filter unit on wheels with a compressed air diaphragm pump to transfer the solutions
- Gold cementation tank
- Graduated tanks for HCl and HNO3. Acid transfer from the reactors by vacuum.
- PPl tray acid containers (HCl and HNO3) are stored.
- Compressed air diaphragm pumpto transfer the solutions
- Polyethylene tanks, fitted onto a trolley to store king waters.
- Metering pumps to transfer the acids into the reactors.
- Condensers in pyrex glass.
The above system can be customized upon request of the customer, the photos submitted are just one example of the many possible system solutions.
Based on the needs of the customer is possible to create customized systems, with suitable characteristics for the process requirements.
|Power supply||Single phase||Three phase||Three phase||Three phase||Three phase||Three phase|
|POWER||1 kW||2.5 kW||7 kW||5.3 kW||7 kW||8 kW|
|Refining capacity* (kg/9h)||3 Kg||6 Kg||12 Kg||20 Kg||22 Kg||32 Kg|
|Weight||85 Kg||290 Kg||550 Kg||450 Kg||500 Kg||500 Kg|
* The daily refining capacity is referred to gold alloys having a gold minimum content of 600/1000 and a silver maximum content of 100/1000.