Plate VII.—Geographical distribution of the molybdenum deposits of the world. By R. B. Moore.
SUMMARY
Molybdenum commands attention because of its growing importance as a steel alloy metal. Although the metallurgy and properties of molybdenum steels are not thoroughly understood and their use is not widespread, especially in this country, accumulating evidence indicates that molybdenum will eventually become one of the common alloy metals. It is used in the form of wire as supports for incandescent light filaments and in electrical apparatus, and may become essential in the manufacture of special steels. It cannot be easily replaced in chemistry, and for its other applications it is better and cheaper than other materials.
Up to 1915 practically all of the molybdenum produced came from Queensland, New South Wales, and Norway. At present more important deposits are being developed in Ontario, Quebec, and British Columbia, Canada, and in Colorado, Arizona, New Mexico, and other western states. The mineral is widely distributed and the discovery of additional deposits is likely if the demand is sufficient to encourage prospecting. The United States has deposits large enough to meet all domestic needs and also to produce a surplus for export. Some molybdenum is obtained from Mexico, Peru, and Spain, but the United States, Great Britain (Canada and Australia), and Norway control the important deposits.
The largest molybdenum deposit in the United States, located at Climax, Colorado, is owned by the Climax Molybdenum Co., a subsidiary of the American Metal Co. (formerly German), and by the Molybdenum Products Co., of Denver, an American company. Other deposits in Colorado are owned by the Primos Chemical Co., a company that had strong German connections before the war, but has been taken over by the Vanadium Products Corporation, an American company. Other producing deposits of the United States are owned by American citizens.
The Knaben mines, the most important in Norway, have been owned since 1905 by an English company, but, according to a report, they have been acquired by a Norwegian company. A number of the deposits of northern Mexico are owned by Americans. Others are owned by the Madero estate (Mexican). The Canadian and Australian deposits are controlled by small, independent operators. Both the United States and Great Britain have ample supplies of molybdenum; France produces none and is dependent upon other countries; Germany, which was much interested in molybdenum before the war, probably has no large stocks on hand.
CHAPTER XI
RADIUM AND URANIUM
By R. A. F. Penrose, Jr.
Radium is a metal and is a product of the disintegration in nature of the metal uranium. Both radium and uranium are elements. Radium has been isolated in its metallic state, but is not used in that form and is known better in the form of its salts, among the most important of which, so far as their uses are concerned, are the bromide, chloride and sulphate.
Wherever uranium occurs in nature, radium is associated with it in certain definable quantities. Uranium can contain, however, only a certain maximum amount of radium at a time, and when it has reached this stage, the radium and uranium ratio is said to be in equilibrium. In this condition the amount of radium per gram of uranium has been calculated by Rutherford to be 3.4 × 10⁻⁷ gram. This corresponds to 1 gram of radium element to about 3,000 kilograms of uranium element, or 1 part of radium element to about 3,000,000 parts of uranium element. Uranium minerals as mined are usually impure and carry only a small percentage of uranium elements, so that the ratio between radium and the crude uranium ore may be 1 to several or many times 3,000,000.