Scrap Gold Blog


Wednesday, 13 April 2016

Extract gold for recycling using bacteria?!

Selling your scrap gold jewellery for extra cash is easy – easy for you and easy for industry to get at the precious metal it contains and reuse it. But it’s hasn’t been such an easy job for people who are recycling gold from electronic waste – until now.

The tried and tested method of extracting scrap gold from old computers and mobile phones involves using dangerous chemicals including cyanide and acids which actually dissolve the precious metals. The gold is then recovered from the chemicals by passing an electric current through the liquid.

Cyanide, which is also used in gold mines to get at the bullion, can be a safety nightmare, with many levels of security put in place to stop the poisonous fumes from escaping.

But now a team at the National University of Singapore has come up with a safer and more environmentally-friendly technology that uses bacteria usually found in soil to do the job.

They’ve created big pools containing the bacteria that can remove gold from old electronic equipment in a week. Although the hazardous chemicals can do the same thing in an hour, the pools containing the bacteria can be used again and again. And they also have the benefit of leaving the gold whole – unlike chemicals, which dissolve it.

The team is three years into a five year project to prove the new idea and they’re working with Singapore electronic waste company Cimelia to refine it. The project itself is costing around $2 million (£1.4 million).

The plant manager’s, Mr Nagendra, told the Straits Times: "We have every intention to use this new technology in our electronic waste recycling process upon the successful completion of the project."

It just shows how badly the industry needs scrap gold if it’s prepared to spend millions on new ways to extract it.

So, if you do have any broken or unwanted gold jewellery tucked away that you think isn’t really worth anything, it might be worth reconsidering.