How are precious metals refined

Refining precious metals involves several methods to purify and separate valuable metals from impurities:

Fire Assay: A traditional method using heat and flux to separate metals like gold and silver from impurities.

Aqua Regia: A chemical process using a mix of hydrochloric and nitric acids to dissolve and refine gold and platinum group metals.

Electrolytic Refining: Metals are dissolved and then redeposited as pure metal using an electric current.

Miller Process: Gold is refined by heating it with chlorine gas to remove impurities.

Wet Chemical (Parting) Method: Used for separating gold from silver using nitric acid.

Solvent Extraction: Selective solvents are used to extract specific precious metals like palladium and platinum.

Zone Refining: A high-purity method used for refining metals, often in the semiconductor industry.

Hydrometallurgical Methods: Aqueous solutions are used to extract metals from ores or waste, commonly used in electronic recycling.

These methods ensure the recovery of pure precious metals for reuse in various industries.