Welcome to Sovereign Metals Limited, a beacon of innovation and excellence in the precious metals industry. We are not just a company; we are a movement, a philosophy, a revolution, and a testament to the transformative power of metals.
In our pursuit of excellence, we have acquired Edelweiss Metals Limited, an eminent precious metal refinery incorporated by the esteemed Edelweiss Group in 2012. This acquisition melds the rich legacy and profound experience of Edelweiss Metals Limited with the visionary zeal of Sovereign Metals Limited, creating a synergy that is set to redefine the industry standards.
Sovereign Metals Limited is a preeminent refinery, featuring well-structured manufacturing units equipped with progressive machinery and technologies. Our facilities are constructed with a keen focus on safety, health, and environmental considerations, ensuring a sustainable and responsible operational footprint. Visitors to our refinery experience an uncluttered and secure atmosphere, reinforcing the assurance that every process is handled with the utmost recision and care.
Our production area is standardized, featuring high-tech facilities that align with our vision of merging today’s technology with tomorrow’s trends. We continuously endeavor to upgrade our equipment, furnishings, and environmental controls to stay ahead in the industry and to lead with purpose.
The process of refining gold involves removing impurities from the raw material—whether it is mined ore, scrap jewelry, or industrial waste—to achieve a high level of purity, typically 99.9% (24-karat) or higher.
Gold refineries generally follow a sequence of mechanical and chemical stages to isolate the precious metal.
1. Pre-Processing and Melting
The process begins by weighing and assaying the incoming material to determine its initial gold content.
- Melting: The gold is melted in a high-temperature furnace.
- Sampling: While molten, a small sample is taken to verify the exact purity before the formal refining begins.
- Granulation: The molten metal is often poured into cold water to create small shots or “cornflakes,” which increases the surface area for faster chemical reactions in the next steps.
2. The Miller Process (Chlorination)
For large-scale refining, the Miller process is often the first major chemical step. It can refine gold to about 99.5%purity.
- Mechanism: Gaseous chlorine is bubbled through the molten gold.
- Reaction: Most impurities (like silver, copper, and iron) react with the chlorine to form chlorides. These chlorides either turn into a gas or form a slag layer that floats on top of the liquid gold and is skimmed off.
3. The Wohlwill Process (Electrolysis)
To achieve “four nines” purity (99.99%), the gold undergoes electrolysis.
- Setup: An impure gold bar acts as the anode (positive pole), and a thin sheet of pure gold acts as the cathode(negative pole). Both are submerged in an electrolyte solution of chloroauric acid.
- The Reaction: When an electric current is applied, the gold dissolves from the anode and plates onto the cathode. Impurities like silver form a sludge at the bottom or stay in the solution.
4. Aqua Regia Refining (Wet Chemical Method)
This method is common for smaller refineries or for processing high-purity scrap.
- Dissolution: The gold is dissolved in Aqua Regia (a mixture of nitric acid and hydrochloric acid in a 1:3 ratio).
- Precipitation: Once the gold is in a liquid state, a chemical like sodium metabisulfite is added. This causes the gold to “drop” out of the liquid as a fine brown powder.
- Wash and Dry: The powder is filtered, washed to remove traces of acid, and then dried.
5. Final Casting and Hallmarking
The refined gold powder or cathode sheets are melted one last time.
- Ingots and Bars: The molten pure gold is poured into molds to create bars of specific weights (e.g., 1kg, 10oz, or 400oz London Good Delivery bars).
- Assaying: A final test is conducted to certify the purity.
- Stamping: The refinery stamps the bar with its logo, the weight, and the purity (e.g., 999.9).
Summary of Purity Levels
| Process | Resulting Purity | Common Use |
|---|---|---|
| Miller Process | 99.5% | Investment bars and jewelry |
| Wohlwill Process | 99.99% | High-end electronics and bullion |
| Aqua Regia | 99.9% – 99.99% | Boutique refining and scrap recovery |
www.sovereignmetals.in
English 