Some Non-Ferrous Metals | ||||
Name | Composition | Properties | Uses | |
Aluminium | Pure Metal | Greyish-White, soft, malleable, conductive to heat and electricity, It is corrosion resistant. It can be welded but this is difficult. Needs special processes. | Aircraft, boats, window frames, saucepans, packaging and insulation, pistons and cranks. | |
Aluminium alloys-Dur |
Aluminium +4% Copper+1% Manganese | Ductile, Malleable, Work Hardens. | Aircraft and vehicle parts. | |
Copper | Pure metal | Red, tough, ductile, High electrical conductor, corrosion resistant, Can work hard or cold. Needs frequent annealing. | Electrical wire, cables and conductors, water and central heating pipes and cylinders. Printed circuit boards, roofs. | |
Brass | 65% copper +35%zinc. | Very corrosive, yellow in colour, tarnishes very easily. Harder than copper. Good electrical conductor. | Castings, ornaments, valves,forgings. | |
Lead | Pure metal | The heaviest common metal. Soft, malleable, bright and shiny when new but quickly oxidizes to a dull grey. Resistant to corrosion. | Protection against X-Ray machines. Paints, roof coverings, flashings. | |
Zinc | Pure metal | A layer of oxide protects it from corrosion, bluish-white, easily worked. | Makes brass. Coating for steel galvanized corrugated iron roofing, tanks, buckets, rust-proof paints | |
Tin | Pure metal | White and soft, corrosion resistant. | Tinplate, making bronze. | |
Gilding metal | 85% copper+15% zinc. | Corrosion resistant, golden colour, enamels well. | Beaten metalwork, jewellery. |
Some Ferrous Metals | ||||
Name | Composition | Properties | Uses | |
Mild Steel | 0.15 to0.30% carbon | Tough, high tensile strength, ductile. Because of low carbon content it can not be hardened and tempered. It must be case hardened. | girders, Plates, nuts and bolts, general purpose. | |
High Speed Steel | medium carbon, tungsten, chromium and vanadium. | Can be hardened and tempered. Can be brittle. Retains hardness at high temperatures. | Cutting tools for lathes. | |
Stainless Steel | 18% chromium, and 8% nickel added. | Corrosion resistant | Kitchen draining boards. Pipes, cutlery, aircraft. | |
High Tensile Steel | Low carbon steel,, nickel,and chromium. | Very strong and very tough. | Gears, shafts, engine parts. | |
High Carbon Steel | 0.70% to 1.40% carbon. | The hardest of the carbon steels. Less ductile, tough and malleable. | Chisels, hammers, drills, files, lathe tools, taps and dies. | |
Medium Carbon Steels | 0.30% to 0.70% carbon. | Stronger and harder than mild steels. Less ductile, tough and malleable. | Metal ropes, wire, garden tools, springs. | |
Cast Iron | Remelted pig iron with small amounts of scrap steel. | Hard, brittle, strong, cheap, self-lubricating.
Whitecast iron, grey cast iron, malleable cast iron. |
Heavy crushing machinery. Car cylinder blocks, vices, machine tool parts, brake drums, machine handle and gear wheels, plumbing fitments. |
Non-ferrous metal
In metallurgy, a non-ferrous metal is a metal that is not ferrous, that is, any metal, including alloys, that does not contain iron in appreciable amounts. Generally more expensive than ferrous metals, non-ferrous metals are used because of desirable properties such as low weight (e.g., aluminum), higher conductivity (e.g., copper), non-magnetic property or resistance to corrosion (e.g., zinc). Some non-ferrous materials are also used in the iron and steel industries. For example, bauxite is used as flux for blast furnaces, while others such as wolframite, pyrolusite and chromite are used in making ferrous alloys.
Important non-ferrous metals include aluminium, copper and the alloy brass, lead, nickel, tin, titanium, and zinc. Precious metals such as gold, silver and platinum are also classified as non-ferrous. Exotic or rare metals such as cobalt, mercury, tungsten, arsenic, beryllium, bismuth, cerium, cadmium, niobium, indium, gallium, germanium, lithium, selenium, tantalum, tellurium, vanadium, and zirconium are also non-ferrous. They are usually obtained through minerals such as sulfides, carbonates, and silicates. Non-ferrous metals are usually refined through electrolysis.
Ferrous metal recycling
The steel industry has been actively recycling for more than 150 years, in large part because it is economically advantageous to do so. It is cheaper to recycle steel than to mine iron ore and manipulate it through the production process to form new steel. Steel does not lose any of its inherent physical properties during the recycling process, and has drastically reduced energy and material requirements compared with refinement from iron ore. The energy saved by recycling reduces the annual energy consumption of the industry by about 75%, which is enough to power eighteen million homes for one year. According to the International Resource Panel's Metal Stocks in Society report, the per capita stock of steel in use in Australia, Canada, the European Union EU15, Norway, Switzerland, Japan, New Zealand and the USA combined is 7085kg (about 860 million people in 2005).
Basic oxygen steelmaking (BOS) uses between 25 and 35% recycled steel to make new steel. BOS steel usually contains lower concentrations of residual elements such as copper, nickel and molybdenum and is therefore more malleable than electric arc furnace (EAF) steel and is often used to make automotive fenders, tin cans, industrial drums or any product with a large degree of cold working. EAF steelmaking uses almost 100% recycled steel. This steel contains greater concentrations of residual elements that cannot be removed through the application of oxygen and lime. It is used to make structural beams, plates, reinforcing bar and other products that require little cold working. Downcycling of steel by hard-to-separate impurities such as copper or tin can only be prevented by well-aimed scrap selection or dilution by pure steel. Recycling one metric ton (1,000 kilograms) of steel saves 1.1 metric tons of iron ore, 630 kilograms of coal, and 55 kilograms of limestone.