Chinese scientists recover 98% of gold from old phones in 20 minutes at low cost
The process achieves over 98.2 percent gold leaching efficiency at room temperature.
By
Jan 08, 2026 03:48 PM EST
Chinese researchers have discovered a fast, low-cost and environmentally cleaner method for extracting gold from electronic waste, that could significantly reshape e-waste recycling worldwide and reduce the need for traditional mining.
The novel technique, that can extract gold from discarded electronics in under 20 minutes
at room temperature was developed by researchers from the Guangzhou Institute of Energy Conversion under the Chinese Academy of Sciences and South China University of Technology.
The team reported that the new process costs about one-third of current market prices for gold recovery which makes it the most cost-efficient method reported to date.
It also achieves more than 98.2 percent gold leaching efficiency from waste CPUs (central processing units) in old mobile phones and PCBs (printed circuit boards) from home appliances at room temperature.
Fast, cheap gold recycling
Electronic waste, or e-waste, is one of the fastest growing solid waste streams in the world. As per the
(WHO), the annual generation of e-waste is rising by 2.6 million tons. It is expected to climb to 82 million tons by 2030.
The most common e-waste items include computers, large household appliances, mobile phones and medical equipment. These items contain small but valuable amounts of
, including gold (Au) and palladium (Pd) which are widely used for their excellent conductivity, stability and corrosion resistance.
Meanwhile, conventional
often rely on toxic chemicals such as cyanide, posing serious environmental and health risks. To address the challenge the team developed a process based on a self-catalytic leaching mechanism.
The mechanism eliminates the need for corrosive reagents or external catalysts. In contrast it uses a simple aqueous solution of potassium peroxymonosulfate (PMS) and potassium chloride (KCl).
When the solution comes into contact with
surfaces, the metals themselves behave as catalysts. On the metal surface, PMS and chloride ions (Cl⁻) are activated, producing highly reactive oxidants such as singlet oxygen and hypochlorous acid.
These oxidants then break down the metal atoms, and allow the chloride ions to bind to them and dissolve them into the solution for easy recovery. For the study, the team carried out quenching experiments and spectroscopic analysis.
Reinventing gold extraction
The researchers noted that the method achieves over 98.2 percent gold leaching efficiency from waste central processing units (CPUs) and printed circuit boards (PCBs), along with a 93.4 percent palladium recovery rate.
This means that processing just 22 lbs (10 kilograms) of discarded circuit boards can yield around 1.4 grams of gold at a total cost of roughly USD 72. This is equal to about USD 1,455 per ounce, which is far below current market prices.
For comparison,
in early January exceeded USD 4.400 per ounce for the first time in history. They’re expected to hit
per ounce by the end of the decade.
Apart from cost savings, the new process consumes approximately 62.5 percent less energy than conventional techniques. It also cuts reagent costs by more than 93 percent compared to cyanide-based methods.
Moreover, it produces far less secondary waster, like toxic sludge. After leaching, the dissolved metals can be recovered through straightforward reduction and purification steps to obtain high-purity gold.