It is a non-volatile and almost infusible white powder, which slowly absorbs moisture and carbon dioxide from air, and is readily soluble in dilute acids.
It is a red infusible mass of specific gravity 5.1, and is slowly decomposed by warm water.
Tantalum pentoxide, Ta205, is a white amorphous infusible powder, or it may be crystallized by strongly heating, or by fusing with boron trioxide or microcosmic salt.
When melted the products separate on the bed (which is made of closely packed sand or other infusible substances), according to their density; the lighter earthy matters forming an upper layer of slag are drawn out by the slag hole K at the flue end into an iron wagon or bogie, while the metal subsides to the bottom of the bed, and at the termination of the operation is run out by the tap hole L into moulds or granulated into water.
It is a white amorphous infusible powder, which when strongly heated in sulphuretted hydrogen, yields an oxysulphide.
It is infusible before the gas blowpipe, but in the oxyhydrogen flame fuses to a clear colourless glass, which has a hardness of 5 and specific gravity 2.2.
Hartley has employed it with great success, and in cyanite (a silicate of aluminium) has found a material which is infusible at the temperature of this flame, and is therefore suitable to hold the substance which it is desired to examine.
These bricks are specially used for the roof, fire arches, and other parts subjected to intense heat in reverberatory steel-melting furnaces, and, although infusible under ordinary conditions, are often fairly melted by the heat without fluxing or corrosion after a certain amount of exposure.
It has been found to stand well for the linings of rotatory puddling furnaces, where, under long-continued heating, it changes into a substance as hard and infusible as natural emery.
It is an infusible solid, which is intensely yellow at a red heat, but on cooling becomes white.