noun
definition
A former name of niobium.
Examples of columbium in a Sentence
Chemically related to vanadium are the two elements tantalum and columbium or niobium.
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.
Columbium hydride, CbH, is obtained as a greyish metallic powder, when the double fluoride, CbF 5, 2 KF, is reduced with sodium.
Columbium trichloride, CbC1 3, is obtained in needles or crystalline crusts, when the vapour of the pentachloride is slowly passed through a red-hot tube.
Columbium pentachloride, CbC1 5, is obtained in yellow needles when a mixture of the pentoxide and sugar charcoal is heated in a current of air-free chlorine.
Columbium pentafluoride, CbF5, is obtained when the pentoxide is dissolved in hydrofluoric acid.
Columbium oxysulphide, CbOS 3, is obtained as a dark bronze coloured powder when the pentoxide is heated to a white heat in a current of carbon bisulphide vapour; or by gently heating the oxychloride in a current of sulphuretted hydrogen.
A heavy white precipitate, consisting of ammonium chloride and columbium nitride, is thrown down, and the ammonium chloride is removed by washing it out with hot water, when the columbium nitride remains as an amorphous residue (Hall and Smith, loc. cit.).
In 1809 he proved the elementary character of columbium (niobium) and titanium.
Of minerals containing this element mention may be made of cassiterite or tinstone, Sn02, tin pyrites, Cu 4 SnS 4 + (Fe,Zn) 2 SnS 4; the metal also occurs in some epidotes, and in company with columbium, tantalum and other metals.
Its history is intermixed with that of columbium.
Wollaston unsuccessfully endeavoured to show that columbium and tantalum were identical.
Blomstrand, and others, especially of Marignac, proved the identity of columbium, dianium and niobium, and that ilmenium was a mixture of columbium and tantalum.
Its double salts with the alkaline fluorides are very important, and serve for the separation of the metal from columbium and titanium.
Columbium pentoxide (columbic acid), Cb205, is obtained from columbite, after the removal of tantalum (see above).
Columbium nitride, Cb3N5 (?), is formed when dry ammonia gas is passed into an ethereal solution of the chloride.
In its chemical relationships tantalum is associated with vanadium, columbium and didymium in a sub-group of the periodic classification.