Salmon sperm transforms rare earth recovery

Separating and recovering rare earth materials is a complicated and expensive process, but one Japanese researcher claims he has discovered a low cost, environmentally friendly extraction alternative.

Yoshio Takahaski, an environmental chemistry professor at Hiroshima University, said a research team which included Japan’s Aisin Cosmos R&D Co. has found that dried salmon sperm is a “low cost and environment-friendly” method to extract rare earth metals, Mineweb reports.

The study built on a 2010 report which determined phosphate groups found on the surface of bacteria can absorb and separate rare earths from the ore 10 times more effectively than the current extraction methods.

Rare earth ores typically contain several of the 17 metals considered essential to manufacturing motors, phone parts and other high-tech products, but separating and recovering the metals proves to be complex because a special type of resin must be used.

Takahaski’s team explored the use of milt, the seminal fluid of fish, which is rich in phosphoric acids and is usually classed as waste, for use in element extraction.

Experimenting with dry, powdered salmon milt, the researchers put it into a beaker containing a rare earth metals solution. What they discovered was that the milt absorbed the rare earth elements as well as bacteria does, particularly the scarce and very expensive elements such as thulium and lutetium.

Unlike bacteria, milt does not have to be cultivated and is easier to preserve in a powdered state.

The findings also indicate that through the chemical enhancement of milt, various other types of rare earth may also be extracted.

Current processing techniques creates radioactive material which has had a polarising affect, especially in regions that have minerals processing plants such as Malaysia.

But the International Atomic Energy Agency said radiation generated from the Malaysian plant is “no cause for concern”.

Rare earths are used in the development of many renewable and environmentally sustainable technologies including wind power, lithium batteries, and electric cars.

Controversial Australian rare earths miner Lynas Corporation began production at its $900 million Malaysian rare-earths plant in December after environmentalist’s legal action resulted in extensive delays.

To date, Lynas has managed to fend off protester’s claims and legal challenges.

Last month Australian Mining reported Lynas was on track to meet its second quarter target of producing 11,000 tonnes per year from its processing plant.

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