The Source Of Aluminium

Northern Advocate, 22 July 1939, Page 6 (Supplement)

The Source Of Aluminium

Commercially unknown less than 100 years ago, aluminium, so familiar in every household to-day, was a product of no apparent importance until well within the last 50 years. It is derived from the bauxite, an iron ore that occurs in many parts of the world. It has the appearance of clay, but is much harder, and its colour ranges from grey to brown, and even red and pink. Rocklike in substance, it is quarried, methods ranging with the nature of the deposit. In the reduction of the clay to aluminium great heat—about 1000 degrees centigrade—is required, and as ample electric power must be available, accessibility to such a supply is often the deciding factor in the location of plants. Alumimuxii in its “straight” condition is little used in engineering, its constitution being such that though lightness is abundantly present

The Light Metal

strength is absent. Consequently it is always allowed with some other metal —mostly Copper—the alloys going under various trade names. Some ol them giv'-' roughly the strength of steel weile retaining approximately one-third of the weight. Pure aluminium has a specific gravity of 2.7 as compared with the figures of 7.8 for mild steel. Besides its advantage of lightness, aluminium and the aluminium alloys are wonderful conductors of heat, giving a decided advantage in such engine parts as the cylinder head, pistons, crankcases, etc. Both aluminium and its alloys are easily machined. There is no danger of aluminium ever running short. It is abundant, being computed at 31.9 per cent., as compared with iron 19.9 per cent, in the earth’s make-up to a depth of 10 miles. There is no fear of ever burning up the aluminium supply.