Molybdenum

“ Molybdenum Green. A clear malachite green colour, when dried, is produced from molybdate of soda and potash-chrome-alum, or from the molybdate and alum with ammonia. Being more expensive than the chrome oxides and not better, its introduction, for use by artists, would be attended with no advantage.
There is likewise obtainable a copper molybdate, by adding neutral molybdate of soda in excess to sulphate of copper. The precipitate is a very pale green colour, flocculent at first, but crystalline after washing. Like the chrome molybdate it would be superfluous as a pigment. ”

“ Pure copper, alloyed with 0•5 per cent of chromium, assumes a double resistance and suffers less change than copper in contact with moist air.
Molybdenum, previously unfused, can also be obtained in notable quantities. By heating, in a continuous electric furnace, a mixture of oxide of molybdenum and charcoal, a melting of the metal is obtained which flows readily and can be easily molded. It furnishes a definite carburet, very well crystallized. It is refined by a new heating in the electric furnace, with an excess of oxide of molybdenum. ”

“ The a of beryllium, the b of calcium and strontium, and d of calcium, the e and f of strontium, are all there; j in chromium is the same as the central sphere in the b ovoid. In the central globe, k, is a pair of triangles as in hydrogen, consisting of only six atoms, which on the meta level revolve round each other, and break up into two duads and two units on the hyper.
Molybdenum (Plate VIII, 6) .
Molybdenum presents us with only two new forms, and these are merely four-atomed tetrahedra, occurring in pairs as object and image. All the other bodies have already been analysed. ”

“ The announcement is also made that the staff of the department of mining of the University of Toronto have discovered a process by which low-grade concentrates of molybdenite can be made at little cost. Molybdenite is used for hardening and toughening steel, and it is most useful in he manufacture of high-speed tools. Quebec is a larger producer, but the need for molybdenite is great, and the new process will, it is stated, render available the deposits of low-grade molybdenum ore which have been discovered in Manitoba and British Columbia. ”

“ One pound of this metal will impart more resiliency to steel than three or four pounds of tungsten. The molybdenum steel, because it does not easily crack, is said to be serviceable for armor-piercing shells, gun linings, air-plane struts, automobile axles and propeller shafts. In combination with its rival as a tungsten-molybdenum alloy it is capable of taking the place of the intolerably expensive platinum, for it resists corrosion when used for spark plugs and tooth plugs. European steel men have taken to molybdenum more than Americans. ”

“ Acids do not act on it—that is, it does not liberate hydrogen from them, not even from hydrochloric acid—but strong sulphuric acid disengages sulphurous anhydride, forming a brown mass, containing a lower oxide of molybdenum. Alkalis in solution do not act on molybdenum, but when fused [297] with it hydrogen is given off, which shows, as does its whole character, the acid properties of the metal. The properties of tungsten are almost identical; it is infusible, has an iron-grey colour, is exceedingly hard, so that it even scratches glass. ”

“ Molybdenum, mol-ib-dē′num, n. a rare metal of a silvery-white colour—also Molybdē′na.—ns. Molyb′date, a compound of molybdic acid with a base; Molybdē′nite, sulphide of molybdenum.—adjs. Molybdē′nous, Molyb′dic.—n. Molybdō′sis, lead-poisoning. [L.,—Gr.,—molybdos, lead.]
Mome, mōm, n. (obs.) a buffoon: a stupid person. [O. Fr.,—L.,—Gr. Mōmos, god of mirth.]
Moment, mō′ment, n. moving cause or force: importance in effect: value, consequence: the smallest portion of time in which a movement can be made: an instant: the precise point of time, the right opportunity: (math.) ”

“ Molybdenum trichloride, MoCl3, is obtained when the pentachloride is heated to a temperature of about 250° C. in a current of hydrogen. It forms red crusts, is insoluble in cold water, but is decomposed by boiling water. It is easily soluble in hot nitric acid. ”

“ The Primos Chemical Co. has since 1919 been taken over by the Vanadium Products Corporation, affiliated with the Bethlehem Steel Corporation. The Molybdenum Products Co., Denver, Colorado, which owns a part of the molybdenum deposit on the slope of Bartlett Mountain, near Climax, and operates a 200-ton mill, is a subsidiary of E. J. Longyear Co., exploring engineers, of Minneapolis, Minnesota. Both companies are owned by American stockholders.
In Canada and Australia it is certain that no one large interest has control, as the ore comes from a number of more or less independent small mines. ”

“ A promising method after previous separation by molybdenum is the one proposed by Pemberton, but it has not yet come into general use. For small quantities of phosphoric acid or of phosphorus, such as are found in steels and irons, the method of Emmerton, either as originally proposed or as modified by Dudley and Noyes, is in frequent use. Where volumetric methods are applied to products separated by molybdic solution, the essential feature of the analytical work is to secure a yellow precipitate of constant composition. ”

“ The second difference is in the composition of the molybdate solution employed. The official molybdate solution contains about sixty grams [Pg 110] of molybdenum trioxid in a liter while the Pemberton solution contains sixty-six grams. There is therefore not much difference in strength. The absence of nitric acid, however, from the Pemberton solution favors the deposition of the molybdic acid when heat is applied. Kilgore, therefore, conducts the analysis as follows: The solution of the sample is made according to the official nitric and hydrochloric acid method for total phosphoric acid. ”

“ In all these three cases the elements of smaller atomic weight (chromium, molybdenum, and tungsten) are able, in their higher grades of oxidation, to give acid oxides having the properties of distinct but feebly energetic acids (in the lower oxides they give bases) , whilst the elements of greater atomic weight (zinc, cadmium, mercury) , even in their higher grades of oxidation, only give bases, although with feebly developed basic properties. The platinum metals present the same intermediate properties such as we have already seen in iron and the elements of the eighth group. ”

“ The natural transition from titanium and vanadium to copper and zinc by means of the elements of the iron group is demonstrated by all the properties of these elements, and in exactly the same manner a transition from zirconium, niobium, and molybdenum to silver, cadmium, and indium, through ruthenium, rhodium, and palladium, is in perfect accordance with fact and with the magnitude of the atomic weights, as also is the position of osmium, iridium, and platinum between tantalum and tungsten on the one side, and gold and mercury on the other. ”

“ All the neutral acetates, except those of molybdenum and tungsten, are more or less soluble in water, several so much so as to be uncrystallizable; many dissolve in alcohol; they suffer decomposition at a dull red heat, and by distillation, at that temperature, yield acetone and water, or acetone and acetic acid, and leave a carbonaceous residuum; at a full red-heat, those of potassium, sodium, barium, strontium, calcium, and magnesium, are converted into carbonates, whilst the other metallic acetates leave behind the pure metal, or its oxide. ”

“ In the pure oxidation flame, a clear yellowish glass is formed; but as soon as the reduction flame reaches it, or the point of the blue cone touches it, the color of the bead changes to a brown, which, finally, after a little longer blowing, becomes quite dark, and loses its transparency. The cause of this is, that the molybdenic acid is very easily reduced to a lower degree of oxidation, or to the oxide of molybdenum. The flame of oxidation will again convert this oxide into the acid, and this conversion is a good test of the progress of the student in the use of the blowpipe. ”

“ The metallic oxide is reduced; the metal unites with the carbon, producing a crystalline carbide, and the oxygen combines with the calcium to form lime. By this method M. Moissan has obtained crystallized carbides of aluminum, manganese, tungsten, molybdenum, titanium, and chromium. In case the metal does not give a combination with carbon, it is obtained in free state as a melted button. There have been reduced in this way by carbide of calcium, to form free metals, the oxides of lead, bismuth, and tin. ”

“ Chromium and its analogues, besides the oxides RO3, also form lower grades of oxidation RO2, R2O3, and the same is seen in uranium; it forms UO3, UO2, U2O3 and their compounds. (3) Molybdenum and tungsten, in being reduced from RO3, easily and frequently give an intermediate oxide of a blue colour, and uranium shows the same property; giving the so-called green oxide which, according to present views, must be regarded as U3O8 = UO22UO3, analogous to Mo3O8. (4) The higher chlorides, RCl6, possible for the elements of this group, are either unstable (WCl6) or do not exist at all (Cr) ”

“ In Mexico the large molybdenum deposit in the Sahuaripa district of eastern Sonora is owned by George Fast, of Douglas, Arizona. The Lucky Tiger-Combination Gold Mining Co., of Kansas City, Mo., (American) owns the deposits in the Montezuma district. Another American company has acquired deposits near Poza, Sonora, about 20 miles north of Hermosillo. A deposit located 35 miles from the port of Topolabampo, northwestern Sinaloa, is owned by an American. The Compañia Minera Aurora y Anexas, operating molybdenum mines near Coyame and Marquez, northeastern Chihuahua, is owned by the Madero estate. ”

“ But not only is the combining power or valency (atomicity) of the elements different, it is also observed that one element may combine with another in several proportions, or that its valency may vary; for example, phosphorus forms two chlorides represented by the formulae PCl3 and PCl5, nitrogen the series of oxides represented by the formulae N2O, NO, (N2O3) , N2O4, N2O5, molybdenum forms the chlorides MoCl2, MoCl3, MoCl4, MoCl5, MoCl6 (?) , and tungsten the chlorides WCl2, WCl4, WCl5, WCl6. ”

“ The anhydrides of the acids are also insoluble in water, but as colloids are sometimes held in solution, just like those of titanic and molybdic acids. Furthermore, niobium is in every respect the nearest analogue of molybdenum, and tantalum of tungsten. Niobium is obtained by reducing the double fluoride of niobium and sodium, with sodium. It is difficult to obtain in a pure state. It is a metal on which hydrochloric acid acts with some energy, as also does hydrofluoric acid mixed with nitric acid, and also a boiling solution of caustic potash. ”

“ Sodium, also, is of growing importance, both for cheapening the production of aluminum, and as a powerful weapon of research. The manufacture of magnesium, which was a curiosity in 1849, has become an important industry. We may confidently expect to see barium and calcium produced on a large scale as soon as their utility has been demonstrated by research. Minerals containing molybdenum are not rare; and the metal could probably be produced as cheaply as tin if a use were to be found for it. ”

“ These are of great importance, and include manganese, chromium, nickel, tungsten, vanadium, antimony, molybdenum, uranium, and zirconium. Radium is closely associated with uranium and is considered with it. Closely allied with zirconium are thorium and mesothorium, and their treatment therefore closely follows that of zirconium.
The next great group is that of the major metals, other than iron and the ferro-alloy metals: copper, lead, zinc, tin and mercury, and aluminum. Aluminum ores are used not only as sources of the metal, but for the manufacture of refractories and abrasives. ”

“ It forms a grey coloured powder of specific gravity 9·01; it is malleable, and not as hard as glass. It is rapidly oxidized on heating to a temperature of 500°–600° C., and also when fused with nitre or potassium chlorate. It is soluble in dilute nitric acid, and in concentrated sulphuric acid; in the latter case with the formation of a blue solution which on heating becomes colourless, molybdenum trioxide being formed with the liberation of sulphur dioxide. ”

“ 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. ”

“ In the molybdate method the rapid precipitation from solutions at 65° was found to give unsatisfactory results and it was found necessary to conduct the process at temperatures between 40° and 50°. With a relative excess of nitric or a relative deficiency of molybdic acid some phosphoric acid may easily escape precipitation. The chief [Pg 70] objection to precipitating at 65° is found in the fact that in presence of considerable iron and alumina some of these bodies may be found in the yellow precipitate, whence they pass to the final ammonium magnesium phosphate. ”