NEW SOURCES OF RADIUM
In 1921, a rich deposit of pitchblende was discovered in the province of Ontario, Canada. Since 1921 there has been a rather considerable exportation of radioactive minerals from Madagascar; and in 1922 deposits of uranium oxide (U3O8) were discovered in Switzerland. During the same year an unknown Belgian traveler sold to a curio dealer a strange stone picked up in the Congo. The dealer sold it to the British Museum. Upon examination the stone was found to be radioactive. Belgian geologists were immediately informed, and a Belgian mission was sent to the Katanga district, where the stone was found. Two veins of chalcolite (torbernite) containing substances rich in radium were soon located by the geologists, one near the Portuguese frontier. Chalcolite, the crystallized phosphate of copper and uranium, is twice as active as uranium.
The newly discovered mineral has been given the name “curite,” in honor of Mme. Curie, the discoverer of radium. These deposits are now known to be the richest in the world. And, what is hardly less important, the radium may be isolated by simple dissolution in nitric acid, even in the cold. It is also readily dissolved in warm hydrochloric acid. Only 15 tons of the ore need to be treated to produce a gram of radium.
Curite is found in three forms, as translucent reddish brown needle-like crystals; as compact saccharoid crystalline aggregates, orange in color; and as orange-colored earthy masses surrounding the preceding variety. The chemical composition is expressed by the formula 2(PbO)5(UO3)4(H2O).
In 1924 a pitchblende deposit, very rich in radium, was discovered in Ferghana, in Russian Turkestan. Soviet Russia is now mining the ore and extracting the radium, which is kept at the Radium Institute of the Academy of Science.
Curiously enough, more than $500,000 worth of radium has been added to the world’s store of this valuable element by “boiling down” British cannons used in the World War. No fewer than five grams—less than a tablespoonful—have been secured by British scientists by this process. The radium is stored in a lead safe weighing almost two tons—a container which was invented by a Dr. Kuss, and the composition of which is known only to himself. One of the greatest difficulties of scientists has been to find some material which would prevent the constant bombardment of the radium rays.
One important result of these recent discoveries—especially that of the Congo deposits—is that the price of radium dropped $30,000 a gram, and sells now at the rate of $70,000 a gram instead of some $100,000. The Standard Chemical Company of Denver, Colorado, has been obliged to close down its three-story laboratory, which until the close of the year 1922 had, for several years previously, been producing a million dollars’ worth of radium annually. The Paradox Valley carnotite ore cannot be worked in competition with the rich deposits of the Belgian Congo. It has been stated that five pounds annually could be produced from these Congo deposits. The Colorado company had been selling at the rate of $58,500,000 a pound. The Congo company can profitably sell the precious element at $29,250,000 less a pound.
So, unless war breaks out again to prevent shipments from abroad, the United States of America will produce no more radium for a long while to come.