Tin, Lead, Zinc, Aluminum: Metallurgy, Properties, and Uses

Tin: Metallurgy, Properties, and Applications

Pyrometallurgical Reduction of Cassiterite

Cassiterite is processed in a reverberatory furnace where tin is reduced by raw coke and subsequently refined.

Electrolytic Recovery of Tin

This process involves inserting crude tin into a sodium hydroxide solution, which dissolves the tin. The metal is then obtained by electrolysis of the solution.

Applications of Tin

Pure tin is used to form alloys such as bronze, and in applications like metal welding, metal printing, antifriction alloys, and low melting point alloys.

Lead: Characteristics, Metallurgy, and Refining

Properties of Lead

Lead is a bluish-gray metal, known for being heavy and soft.

Metallurgy of Lead

Galena is often used as the starting material. Rich and finely divided galena is subjected to roasting, converting it into lead monoxide. It is then processed into metallic lead in a blast furnace where coke is introduced, acting as both fuel and reductant. The molten metal and slag fall into the crucible, from which they are separated and removed. The lead thus obtained is called bullion lead and contains impurities such as copper, tin, arsenic, antimony, bismuth, and silver. Electrolytic refining is then performed to purify it further.

Zinc: Properties, Production, and Uses

Characteristics of Zinc

Zinc is a white-colored metal, very brittle at ordinary temperatures. It becomes malleable between 120-150 °C and brittle again between 200-300 °C. While it oxidizes in moist air, it offers good resistance to corrosion.

Zinc Metallurgy

Zinc is mainly produced from sulfide, oxide, and carbonate ores. First, sulfide and carbonate minerals are transformed into oxides. Carbonates are heated in the absence of oxygen, and sulfides are subjected to roasting. The resulting zinc oxide is then reduced with carbon in an electric furnace. The zinc obtained by this method is called Spelter.

Zinc Alloys

Common zinc alloys include:

• Brass
• Bronze
• Nickel Silver (Alpaca)

Applications of Zinc

Zinc is widely used for:

• Roofing sheets
• Gutters and water downspouts
• Buckets and water tanks
• As a protective or galvanized layer for other metals
• In dry cell batteries

Aluminum: Properties and Extraction

Characteristics of Aluminum

Aluminum is one of the main components of the Earth's crust. It is a silvery-white metal. Its melting point is low, its thermal conductivity is high, it has a strong affinity for oxygen, and possesses high malleability and ductility.

Metallurgy of Aluminum

Separation of Alumina

Alumina is extracted from bauxite. Impurities in the bauxite can be separated from sodium aluminate by filtration. Alumina hydrate, obtained from this process, becomes anhydrous alumina upon calcination.