Deposits of copper, tin, iron and tungsten have been discovered, and a variety of other mineral products (graphite, mica, spodumene, coal, petroleum, &c.).
Similar potassium tungsten bronzes are known.
Considerable quantities of the following minerals have been found: barytes (heavy spar), magnetite (magnetic iron ore), and pyrolusite (manganese dioxide) in Humboldt county; roofing slate in Esmeralda county; cinnabar (ore containing quicksilver) in Washoe county; haematite in Elko and Churchill counties; cerussite and galena (lead ores) in Eureka county; and wolframite (a source of tungsten) at Round Mountain, White Pine county.
Again, when tungsten hexachloride is converted into vapour it is decomposed into chlorine and a pentachloride, having a normal vapour density, but as in the majority of its compounds tungsten acts as a hexad, we apparently must regard its pentachloride as a compound in which an odd number of free affinities are disengaged.
Hjelm in 1783, and tungsten by Don Fausto d'Elhuyar; manganese was isolated by J.
Shimizu 3 indicate that Steinmetz's formula holds for nickel and annealed cobalt up to B =3000, for cast cobalt and tungsten steel up to B =8000, and for Swedish iron up to B =18,000, the range being in all cases extended at the temperature of liquid air.
This retardation was still more pronounced in the case of tungsten-steel, which lost its magnetism at 910° and remained nonmagnetic till it was cooled to 570°, a difference of 240°.
They found that the permeability of Swedish iron, tungsten-steel and nickel, when the metals were cooled to - 186°, was diminished in weak fields but increased in strong ones, the field in which the effect of cooling changed its sign being 115 for iron and steel and 580 for nickel.
The hysteresis-loss in Swedish iron was decreased for inductions below about 9000 and increased for higher inductions; in tungsten-steel, nickel and cobalt the hysteresis-loss was always increased by cooling.
The effect of the addition of tungsten in increasing the coercive force is very clearly shown; in two specimens containing respectively 3.44 and 2.35% of tungsten the coercive force was 64.5 and 70.7.
These high values render hardened tungsten-steel particularly suitable for the manufacture of permanent magnets.
2 The results are too numerous to discuss in detail; some of those to which special attention is directed are the following: In Swedish iron and tungsten-steel the change of elastic constants (Young's modulus and rigidity) is generally positive, but its amount is less than 0.5%; changes of Young's modulus and of rigidity are almost identical.
Columbium compounds are usually prepared by fusing columbite with an excess of acid potassium sulphate, boiling out the fused mass with much water, and removing tin and tungsten from the residue by digestion with ammonium sulphide, any iron present being simultaneously converted into ferrous sulphide.
In 1858 he pointed out the isomorphism of the fluostannates and the fluosilicates, thus settling the then vexed question of the composition of silicic acid; and subsequently he studied the fluosalts of zirconium, boron, tungsten, &c., and prepared silicotungstic acid, one of the first examples of the complex inorganic acids.
The fact that energy is being used at so high a rate as Too H.P. on so small a charge of material sufficiently indicates that the furnace is only used for experimental work, or for the fusion of metals which, like tungsten or chromium, can only be melted at temperatures attainable by electrical means.
Steels containing as much as 12% of tungsten are now used as a material for tools intended for turning and planing iron and steel.
It alloys with iron, molybdenum and tungsten, but not with silver or mercury.
In its improved form this meter consists of a single horseshoe permanent magnet formed of tungsten-steel having a strong and constant field.
615,700 was granted March 16 1897, and related principally to the use of aluminium as a reducing agent for the production of carbonfree metals such as cobalt, chromium, magnesium, tungsten, etc., by what is now known as the aluminothermic process.
Of tungsten the United States was in 1907 the greatest producer in the world (1640 tons in a total of 6062).
It is a member of the sixth group in the periodic classification of the elements, being included in the natural family of elements containing molybdenum, tungsten and uranium.
This subject is far from being exhausted, and it is not improbable that the alloy-producing capacity of aluminium may eventually prove its most valuable characteristic. In the meantime, ternary light alloys appear the most satisfactory, and tungsten and copper, or tungsten and nickel, seem to be the best substances to add.
(Tungsten steel and certain classes of manganese steel are malleable only when red-hot.) Normal or carbon steel contains between 0.30 and 2.20% of carbon, enough to make it harden greatly when cooled suddenly, but not enough to prevent it from being usefully malleable when hot.
Tungsten steel, which usually contains from 5 to Io% of tungsten and from 1 to 2% of carbon, is used for magnets, because of its great retentivit.y.
Chrome-tungsten or High-speed Steel.-Steel with a large content of both chromium and tungsten has the very valuable property of " red-hardness," i.e.
This effect of chromium, tungsten and carbon jointly consists essentially in raising the " tempering temperature," i.e.
Tungsten has been applied in the manufacture of filament electric lamps.
Tungsten trioxide, W0 31 occurs in nature as wolframine, a yellow mineral found in Cumberland, Limoges, Connecticut and in North Carolina.
In unlimited supply, important deposits of rich iron ores suitable for smelting purposes; and for the manufacture of steel of certain descriptions abundance of manganese, chrome and tungsten ores are available.
Scheelite, another mineral of tungsten, is also found in Queensland.
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 PC1 3 and PC1 51 nitrogen the series of oxides represented by the formulae N 2 0, NO, (N203), N 2 O 4, N205, molybdenum forms the chlorides MoC1 2, MoC1 3, MoC1 4, MoC1 5, MoCls(?), and tungsten the chlorides WC1 2, WCl 4, WC1 5, WC16.
So long as Mr. Lloyd George was Minister, Dr. Addison was his right-hand man in the strenuous labours of the office, resulting in the enormous multiplication of engines of war, and in the redeeming of many vital industries, fertilizers, tungsten and potash from German control; and when Mr. Lloyd George formed a Government himself in December 1916, he placed him at the head of the department.
Anodic polarization in potassium chloride solution renders molybdenum, niobium, ruthenium, tungsten, and vanadium passive (W.
South-west of the city, has been obtained since 1900 most of the tungsten mined in the United States; the output in 1907 was valued at about $520,000.
Minerals developed slightly, or not at all, are granite, valued at $1500 in 1905; surface salt, in the arid and semiarid regions; nickel and cobalt, in Lemhi county; tungsten, near Murray, Shoshone county; monazite and zircon, in certain sands; and some pumice.
Tungsten is found in wolframite in Boulder county.
TUNGSTEN [[[symbol]] W, atomic weight 184 o (0=16)], a metallic chemical element found in the minerals wolfram, an iron and manganese tungstate, scheelite, a calcium tungstate, stolzite, a lead tungstate, and in some rarer minerals.
Tungsten may be prepared from wolfram by heating the powdered ore with sodium carbonate, extracting the sodium carbonate with water, filtering and adding an acid to precipitate tungstic acid, H 2 W0 4.
Tungsten dioxide, W02, formed on reducing the trioxide by hydrogen at a red heat or a mixture of the trioxide and hydrochloric acid with zinc, or by decomposing the tetrachloride with water, is a brown strongly pyrophoric powder, which must be cooled in hydrogen before being brought into contact with air.
Partial reduction of tungsten trioxide gives blue or purple-red products which are intermediate in composition between the dioxide and trioxide.
Tungsten trioxide forms two acids, tungstic acid, H 2 WO 4, and metatungstic acid, H2W4013; it also gives origin to several series of salts, to which the acids corresponding are unknown.
By partial reduction of the tungstates under certain conditions products are obtained which are insoluble in acids and alkalis and present a bronze-like appearance which earned for them the name of tungsten bronzes.