noun
definition
A chemical element (symbol Bi) with an atomic number of 83: a brittle silvery-white metal.
definition
A single atom of this element.
Examples of bismuth in a Sentence
There are veins of bismuth near Sodaville.
As another instance of this kind, the decomposition of bismuth chloride by water may be cited.
Manganese ore is mined for export, and bismuth is reported to have been discovered.
The large Hall effect in bismuth was discovered by Righi, Journ.
Bismuth is known to exist in all the Australian states, but up to the present time it has been mined for only in three states, viz.
If a very large quantity of water be added, the chloride is entirely decomposed in the manner represented by the equation BiC1 3 -fOH, = BiOCI -F2HC1, Bismuth chloride.
Most metals form carbonates (aluminium and chromium are exceptions), the alkali metals yielding both acid and normal carbonates of the types Mhco 3 and M 2 CO 3 (M = one atom of a monovalent metal); whilst bismuth, copper and magnesium appear only to form basic carbonates.
By the joint action of water and air, thallium, lead, bismuth are oxidized, with formation of more or less sparingly soluble hydroxides (ThHO, PbH 2 O 2, BiH303), which, in the presence of carbonic acid, pass into still less soluble basic carbonates.
Bismuth is similarly attacked, but slowly, at a white heat.
Bismuth and antimony give (the latter very readily) sesquioxide (Bi 2 O 3 and Sb203, the latter being capable of passing into Sb204).
Moreover, zinc and bismuth were confused, and the word spiauter (the modern spelter) was indiscriminately given to both these metals.
Within these limits are to be found most of the minerals known - gold, silver, quicksilver, copper, lead, zinc, iron, manganese, wolfram, bismuth, thorium, vanadium; mica, coal, &c. On or near the coast are coal, salt, sulphur, borax, nitrates and petroleum.
It may conveniently be extended to similar mixtures of sulphur and selenium or tellurium, of bismuth and sulphur, of copper and cuprous oxide, and of iron and carbon, in fact to all cases in which substances can be made to mix in varying proportions without very marked indication of chemical action.
Spring has shown that by compressing a finely divided mixture of i 5 parts of bismuth, 8 parts of lead, 4 parts of tin and 3 parts of cadmium, an alloy is pro duced which melts at ioo C., that is, much below the meltingpoint of any of the four metals.
Various compounds of the alkali metals with bismuth, antimony, tin and lead have been prepared in a pure state.
Alloys represented by points on Ee, when they begin to solidify, deposit crystals of lead and bismuth simultaneously; Ee is a eutectic line, as also are E'e and E"e.
In the cases of aluminium dissolved in tin and of mercury or bismuth in lead, it is at least probable that the molecules in solution are Al 2j Hg 2 and Bit respectively, while tin in lead appears to form a molecule of the type Sn4.
The presence of minute quantities of cadmium, lead, bismuth, antimony, arsenic, tin, tellurium and zinc renders gold brittle, 2 ' 0 15th part of one of the three metals first named being sufficient to produce that quality.
A native gold amalgam is found as a rarity in California, and bismuth from South America is sometimes rich in gold.
It appears that amalgamation is often impeded by the tarnish found on the surface of the gold when it is associated with sulphur, arsenic, bismuth, antimony or tellurium.
It is necessary to remove as completely as possible any lead, tin, bismuth, antimony, arsenic and tellurium, impurities which impair the properties of gold and silver, by an oxidizing fusion, e.g.
In this process all the anode metals pass into solution except iridium and other refractory metals of that group, which remain as metals, and silver, which is converted into insoluble chloride; lead and bismuth form chloride and oxychloride respectively, and these dissolve until the bath is saturated with them, and then precipitate with the silver in the tank.
The principal source of bismuth is the native metal, which is occasionally met with as a mineral, usually in reticulated and arborescent shapes or as foliated and granular masses with a crystalline fracture.
Bismuth occurs in metalliferous veins traversing gneiss or clay-slate, and is usually associated with ores of silver and cobalt.
It is the chief commercial source of bismuth.
The oxide, bismuth ochre, Bi 2 O 3, and the sulphide, bismuth glance or bismuthite, are also of commercial importance.
The former is found, generally mixed with iron, copper and arsenic oxides, in Bohemia, Siberia, Cornwall, France (Meymac) and other localities; it also occurs admixed with bismuth carbonate and hydrate.
Bismuth is extracted from its ores by dry, wet, or electro-metallurgical methods, the choice depending upon the composition of the ore and economic conditions.
The extraction from ores in which the bismuth is present in the metallic condition may be accomplished by a simple liquation, or melting, in which the temperature is just sufficient to melt the bismuth, or by a complete fusion of the ore.
The fusion process is preferably carried out in crucible furnaces; shaft furnaces are unsatisfactory on account of the disintegrating action of the molten bismuth on the furnace linings.
A certain amount of bismuth sulphate is always formed during the calcination; this is subsequently reduced to the sulphide and ultimately to the metal in the fusion.
Calcination in reverberatory furnaces and a subsequent smelting in the same type of furnace with the addition of about 3% of coal, lime, soda and fluorspar, has been adopted for treating the Bolivian ores, which generally contain the sulphides of bismuth, copper, iron, antimony, lead and a little silver.
The lowest layer of the molten mass is principally metallic bismuth, the succeeding layers are a bismuth copper matte, which is subsequently worked up, and a slag.
In the wet process the ores, in which the bismuth is present as oxide or carbonate, are dissolved out with hydrochloric acid, or, if the bismuth is to be extracted from a matte or alloy, the solvent employed is aqua regia or strong sulphuric acid.
The solution of metallic chlorides or sulphates so obtained is precipitated by iron, the metallic bismuth filtered, washed with water, pressed in canvas bags, and finally fused in graphite crucibles, the surface being protected by a layer of charcoal.
Another process consists in adding water to the solution and so precipitating the bismuth as oxychloride, which is then converted into the metal.
A dry method of purification consists in a liquation on a hearth of peculiar construction, which occasions the separation of the unreduced bismuth sulphide and the bulk of the other impurities.
Hampe prepared chemically pure bismuth by fusing the metal with sodium carbonate and sulphur, dissolving the bismuth sulphide so formed in nitric acid, precipitating the bismuth as the basic nitrate, redissolving this salt in nitric acid, and then precipitating with ammonia.
The bismuth hydroxide so obtained is finally reduced by hydrogen.
Bismuth is a very brittle metal with a white crystalline fracture and a characteristic reddish-white colour.
In the last case it becomes coated with a greyish-black layer of an oxide (dioxide (?)), at a red heat the layer consists of the trioxide (B1203), and is yellow or green in the case of pure bismuth, and violet or blue if impure; at a bright red heat it burns with a bluish flame to the trioxide.
Bismuth combines directly with the halogens, and the elements of the sulphur group. It readily dissolves in nitric acid, aqua regia, and hot sulphuric acid, but tardily in hot hydrochloric acid.
Bismuth readily forms alloys with other metals.
A brittle potassium alloy of silver-white colour and lamellar fracture is obtained by calcining 20 parts of bismuth with 16 of cream of tartar at a strong red heat.
When present in other metals, even in very small quantity, bismuth renders them brittle and impairs their electrical conductivity.
Bismuth forms four oxides, of which the trioxide, B1203, is the most important.
This compound occurs in nature as bismuth ochre, and may be prepared artificially by oxidizing the metal at a red heat, or by heating the carbonate, nitrate or hydrate.
The hydrate, Bi(OH) 3 i is obtained as a white powder by adding potash to a solution of a bismuth salt.
Bismuth dioxide, BiO or Bi 2 O 2, is said to be formed by the limited oxidation of the metal, and as a brown precipitate by adding mixed solutions of bismuth and stannous chlorides to a solution of caustic potash.
Bismuth tetroxide, Bi 2 O 4, sometimes termed bismuth bismuthate, is obtained by melting bismuth trioxide with potash, or by igniting bismuth trioxide with potash and potassium chlorate.