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Gold from the Sea?

TEN years ago commercial extraction of any of the score of valuable elements present in theocean was as impossible as alchemy. Today it is an accomplished fact in the production ofbromine, a vital ingredient in the manufacture of anti-knock gasoline.

And I feel safe in predicting that within the next decadeand possibly even within the nextyearwe will be able to recover gold, silver, radium and all the other untold wealth from thesea, says Thomas Midgley, vice president of the Ethyl-Dow Chemical company, whoseresearch promises this modern miracle.

Midgley, who received the William H. Nichols medal of the American Chemical Society for hisdiscovery of knockless gasoline through the application of tetraethyl lead, then continued: Nowthat we have made one dream a reality, it is only a matter of further technical development andrefinement of processes before we make the sea loosen its hold on a fortune so fabulous that itstaggers the imagination.

The process for taking gold from sea water is no more difficult a problem today than was thetask of ex- tracting bromine ten years ago. Tomorrow we shall probably be wondering how weoverlooked some simple discovery that will unlock the door.

In fact, the sea is the greatest storehouse of wealth on the earth. Once the secret of tapping it isknown, it will give man an inexhaustible treasure house of riches he will be able to draw on forthousands of years without striking bottom.

Bromine is used in synthetic chemistry, medicine and the color industry, but its chief value atpresent is in the manufacture of what motorists know as ethyl.* It is a dark reddish-brown non-

metallic liquid never found free in nature but occurring in spring waters, salt deposits and certainsilver ores in addition to sea water. Heretofore it has been commercially prepared from bittern,the residue left after salt has crystallized. The Ethyl-Dow company has been working for yearson the problem of producing bromine directly from sea water, its most logical source.

As everyone knows, sea water is slightly alkaline, Midgley explains. To make it give up its

bromine, it is only necessary to shift it to the acid side. In our plant we accomplish this by addinga small amount of sulphuric acid.

The Ethyl-Dow plant for the production of bromine, near Wilmington, N. C, is a series of sealedchambers in which occurs an amazing metamorphosis through chemical prestidigitation. Located

almost at the oceans edge, the plant draws its raw material through a large canal into whichthe sea water gushes and booms like the surf. In the first chamber the water receives its injectionof sulphuric acid to make the subsequent transformation possible. Then, in another room,chlorine is added. Chlorine and bromine, which is in the water in the form of sodium bromide,are related. The chlorine, however, is the more active and soon joins with the sodium, kickingthe bromine out.

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As soon as the bromine starts to emerge in a combination of gas and solids looking somethinglike smoke, the water is pumped to the top of the bromine towers and poured down in a fan-shaped shower. A current of air is forced through this shower, not strong enough to carry awaythe spray but sufficiently strong to blow the bromine fumes into another chamber. Here a showerof soda-ash solution is sprayed from the roof. The soda ash has an affinity for the bromine,

precipitating bromide-bromate, which is commonly known as mining salt. This is pumped intothe ethylene di-bromide building, where it is made into ethyl fluid.

One factor making the extraction of gold at the Ethyl-Dow plant a probability of the near futureis the theory that in extracting the bromine, the gold content in the sea water becomes ionized, orelectrically conductive. Since gold in its native state in the water exists in the form of a colloidalsuspension, it is much more difficult to remove than bromine, but if it becomes ionized, it couldbe filtered by making it adhere to some cheap chemical substance.

One of the chief obstacles to the profitable extraction of gold from sea water has been theprohibitive cost of pumping. With the water already running through the plant for the elimination

of bromine, gold could be made a by-product. The water pumped up in the course of one day inthe bromine process contains more than $1,000 in gold. It also contains, in varying quantities,radium, silver and many other valuable elements.

There are 600,000,000 pounds of bromine in a cubic mile of water. In the Ethyl-Dow plant,15,000 pounds a day are removed from 30,000,000 gallons of water, or approximately$2,000,000 worth of bromine annually. In that same cubic mile of water there is $10,000,000 ingold and there are approximately 300,000,000 cubic miles of water in the oceans of the world.