Tin, a soft white metal, was one of the first metals that humans learned to work with. Scientists believe that tin was mined much earlier than iron was first found.
Some archeological finds confirm that tin mines on the territory of present Iraq worked already four thousand years ago. Tin was traded: merchants exchanged it for gold and precious stones. In nature, tin is contained in the oxide of tin ore cassiterite, a mineral whose deposits are found in Southeast Asia, South America, Australia, and China.
According to historians and archaeologists, tin was first discovered, most likely by accident, in overburdened deposits of cassiterite. Ancient mines with waste slag were found in southwestern Britain. Pewter is very rare among the items discovered from Ancient Rome and Greece, which supports the assumption that this metal was expensive.
Pewter is mentioned in works of Arabic literature from the eighth to ninth centuries, as well as in medieval describes travel and significant discoveries. In Bohemia and Saxony, tin was mined in the 12th century.
Interestingly, long before people mined, pure tin, bronze, an alloy of tin and copper, was invented. According to some data, bronze manned is as early as 2500 BC.
Tin exists in ores together with copper, which is why smelting produced not pure copper but its alloy with tin, i.e. bronze. Tin as an accidental impurity can be found in copper utensils of Egyptian pharaohs, made in 2000 BC.
Chemical properties of tin
Tin is inert to water and oxygen at room temperature. The metal also coats with a thin oxide film in the open air. It is the chemical inertness of tin under normal conditions that have made the metal popular with tin container manufacturers.
Sulphuric and hydrochloric acids, when diluted, affect tin extremely slowly, while in a concentrated form they dissolve it when heated. When combined with hydrochloric acid, tin chloride is produced; when reacted with sulphuric acid, tin sulfate is produced.
Reacting with dilute nitric acid produces tin nitrate; reacting with concentrated nitric acid produces insoluble acid. Tin compounds are of great industrial importance: they are used in the production of galvanic coatings.
Applications of tin
This silvery-white soft metal can be rolled into a thin foil. Tin does not rust, so it is widely used in a variety of applications. Metal is most commonly used to make containers. When pewter is finely coated on another metal, it gives the surface a distinctive shine and smoothness.
This property of tin is used in the manufacture of tin cans. Tin is often used as an anti-corrosion coating. More than a third of the tin mined in the world today, is used in the production of food and beverage containers. Tin cans, familiar to everyone, are made of steel coated with a layer of tin no thicker than 0.4 µm.
Another third of the tin mines goes into the production of solder, an alloy with lead in various proportions. Soldiers are used in electrical engineering and for soldering pipelines. Such alloys may contain up to 97% of tin, copper, and antimony, which increases the hardness and strength of the alloy.
Tin mixed with antimony is used to make tableware (primarily Frazier). Industry uses tin in various chemical compounds.