The first metal discovered was copper, still in prehistory, in the middle east. With the discovery of this material and subsequently of other metals it was possible to develop more efficient tools than those of stone. Thanks to the metal, it was possible to manufacture the wheel. The iron was also discovered in the prehistory, however, the steel, as we know today, was only developed in the year 1856, reaching great repercussion in the industrial environment. This is because steel is more resistant than cast iron and can be produced in large quantities, serving as raw material for various industries. With the technological advancement of the furnaces and the growing demand for products made of iron and steel, the steel industries increased production. However, the growth of this sector also brought an increase in the extraction of wood for coal production and the emission of pollutant gases in the atmosphere by burning charcoal. According to Worldsteel (global iron association), the world production of crude steel in 2014 was 1.66 billion tons, corresponding to a growth of 1.2% compared to the previous year. Iron and steel are found in agriculture (ceilers, harvesters, sowers, plows, etc.), in transport (caminions, cars, ships, planes etc.), in civil construction, in the automobile industry, in packaging, domestic appliances and many other utilities. See below the main types of metals and their applications: - Iron: household utensils, tools, car parts buildings structures, food and beverage cans;- Steel: food cans, automobile parts and steel for construction;- Aluminium: drinking cans and squarries;- Copper: telephone cables and electrical windings and pipelines;- Lead: car batteries and homes;- Nickel: mobile batteries;- Zinc: roofs and batteries;- Mercury: fluorescent lamps and batteries. Composition of Metal Ore are substances found in soils and rocks from where it is possible to extract metals. Some metals, such as iron and copper, are extracted from the ore already in the form to be used. Others, such as steel and bronze, need to be associated with other substances.