Aluminium & Non-Ferrous Foundries
Casting Aluminium and Non-Ferrous Metals
Non-ferrous foundries serve critical industrial sectors by producing cast components from metals that do not contain iron. These non-ferrous metals-such as aluminium, copper, zinc, lead, nickel, and tin-are valued for their corrosion resistance, non-magnetic properties and high malleability, which are superior to that of ferrous metals. Aluminium is the most important of non-ferrous metals and is the third most abundant element in the Earth's crust, found in over 270 different minerals.
Foundries working with non-ferrous metals require specialised high-temperature technologies, including melting furnaces, transfer vessels and thermal linings that are engineered to meet the unique chemical and mechanical demands of non-ferrous casting processes.
The discovery and isolation of aluminium
Various compounds containing aluminium were used in pottery, dye-making and medicine for several thousand years before the metal itself was isolated in pure form. During the first half of the nineteenth century, scientists succeeded in producing only small amounts of aluminium, which was then regarded as a precious metal, comparable to gold and silver. Large-scale production remained commercially unviable until the 1880s.
From bauxite to aluminium: The Hall-Héroult process
The first step toward commercial production was the ability to extract alumina, or aluminium oxide, from the mineral bauxite. This development was initially driven by the need to fix dyes in textile manufacturing. While alumina has various industrial uses in its own right, it can also be smelted into aluminium using the Hall-Héroult electrolytic process. This process is named after Charles Martin Hall, an American, and Paul Héroult, a Frenchman, who independently arrived at the same method at the same time.
Aluminium properties and industrial applications
Aluminium is lightweight, an excellent conductor of electricity, non-sparking when struck, and naturally corrosion-resistant. These characteristics have led it to become the second most widely used metal globally after steel. It has replaced copper and cast iron in cookware, is used in the construction of aircraft and automotive applications, features in the building and construction sector, supports electrical infrastructure, and is found in beverage cans and other food packaging materials.
Non-ferrous metals used in foundries
Other non-ferrous metals used extensively in industry include copper, zinc, lead, nickel, and tin, often referred to as base metals. Copper is well known for its excellent electrical conductivity. Around two-thirds of all copper is used in electrical applications, while another quarter is used in pipework, as it inhibits the growth of bacteria in water systems. Zinc is widely used to apply a corrosion-resistant coating to steel (galvanisation). When combined with copper, it forms brass, and it also appears in consumer products such as sunscreens and deodorants.
Lead is extremely soft and easy to work with. Historically used in pipework and paints, it has largely been replaced due to health concerns. Today, around 80% of lead is used in battery manufacturing. It also plays a role in radiation shielding, optical applications, and roofing. Most nickel is used in the production of stainless steel, but it is also found in batteries and magnets, especially for energy and electronics applications. Tin is widely used in soldering and as tinplate, which protects steel and other metals from corrosion, especially in food-safe packaging.