Chemists located the treasure long ago,
and the knowledge that many valuable elements, including gold, are
found in sea water has nourished a long dream of riches. But try as
they would, no seawater miners could recover precious metals in
practical quantities. Germany's famed Chemist Fritz Haber spent years
after World War I trying to extract gold from the ocean to pay off his
country's war reparations. He failed, and finally gave up the struggle.
But in Angewandte Chemie another German chemist
tells how he took a long step toward success, using subtle modern
techniques. Copper Blue Blood. While Professor Ernst Bayer of Tubingen University
was still a graduate student, he began to study the ability of marine
animals to concentrate some of the rare metals found in sea water. The
sea squirt, Phallusia mamillata, for example, has 1,000,000 times
more vanadium in its blood than the water it lives in; the deep blue
blood of the octopus has 100,000 times as much copper. If sea squirts
and octopuses can do the trick, asked Bayer, why shouldn't human
chemists? From octopus blood he extracted hemocyanin, a protein that picks up
copper because its molecule has a structure that a copper ion fits into
neatly, like a key into a lock. But proteins are hard to handle and
almost impossible to synthesize, so Bayer looked for simpler compounds
that would do the same job. After many tries, he put together a black
granular material that picks up copper and uranium only. When this
“chelating agent” worked well in the laboratory with simulated sea
water, Bayer took it to Naples, put it in a glass column and ran 100
liters of real sea water through it. Then he flushed the
chelating agent with dilute hydrochloric acid. Analysis proved that the
acid had picked up 450 micrograms of copper and 50 micrograms of
uranium, the precise amounts present in 100 liters of Bay of Naples
water. .000000049 Oz. His achievement was impressive, but Bayer had his eye on
the much more difficult feat of capturing the ocean's gold. He
concocted another chelating agent with an appetite for gold and went
back once more to Naples. There he put a pinch of the new compound in
100 liters of sea water and shook the mixture mechanically for twelve
hours. Then he filtered out the chelating agent and washed it with
acid. The result: 1.4 micrograms of gold , the exact
amount in 100 liters of Naples sea water. Dr. Bayer himself is not much interested in the practical aspects of
ocean gold mining, but he suggests that his method be tried in more
favorable places where the water contains more gold than the Bay of
Naples. Placed in a stream of sea water that is being pumped through a
power-station condenser or a desalinization plant, the chelating
compound would work quietly, collecting gold that could be extracted at
intervals by washing with acid.
