Valuable Newspapers

Posted on July 8, 2008

Hold onto that old newspaper, it could be worth its weight in gold. That’s the message from Japanese scientists who say that newsprint is a vital ingredient in a new process for recovering gold and other precious metals from industrial waste metal solutions. They say the treated paper can hold its weight in gold.

Old electronic consumer devices such as computers, televisions and mobile phones are an important source of precious metals, which are used in their manufacture. But recovering the metals isn’t easy and usually requires large quantities of chemicals that are known to damage the environment.

Now a team of Japanese chemists says it can do a similar job using inexpensive and renewable materials by crushing and washing old newspapers and then combining the pulp with a chlorine compound, eventually forming what they call a DMA-paper gel. Finally, this is dried to powder form.

They tested the DMA-paper gel’s ability to bind to, or adsorb, metal using a standard industrial sample consisting of a liquor produced by dissolving old metallic components in hydrochloric acid.

The gel turned out to be highly selective in the metals it adsorbed. It took up over 90% of the gold, platinum and palladium, but almost negligible quantities of copper, zinc and iron.

The nature of the cellulose within the paper allows chemicals to penetrate easily and leads to a high carrying capacity – one kilogram of gel can hold 906 grams of gold.

The gel is said to be reusable after the metal is removed. Another fine example of finding ways to reuse products than having to find ways to dispose of them.