Researchers Isolate Copper- Extracting Bacteria

meckardt writes "Using biological processes to retrieve metals from a subtrate has been at best a topic of science fiction. However, in today's news a Japanese-Chilean research firm reported a breakthrough in developing new technology that uses bacteria to extract copper from poor quality mineral at a low cost."

Comments

Re:Gold, silver, etc.?

[Kevin Burtch]

Actually, yes.

Error in story

[barakn]

meckardt writes "Using biological processes to retrieve metals from a subtrate has been at best a topic of science fiction."

Bacteria have been used in the copper and iron mining industries for a long time, especially for the sulfide ores. There's a diagram in the 6th edition (1991) of Biology of Microorganisms by Brock and Madigan, p. 650, of the microbial leaching of copper sulfide minerals. Water containing a ferric sulfate solution is dribbled over a pile of copper sulfide ore. Using oxygen or ferric iron and water, bacteria oxidize the copper into the soluble Cu2+, with ferrous iron, water and sulfate as byproducts. The water moves to a non-biological stage where the Cu2+ is reduced to metal by reacting with iron scrap metal. The iron is oxidized to the soluble ferrous form. In the last stage, another microbe, Thiobacillus ferrooxidans, oxidizes the ferrous ions to ferric ions, and the ferric sulfate solution is pumped back to the top of the hill (occasionally sulfuric acid is added).