Lead Metal

Lead rarely occurs naturally but is often associated with zinc, silver, and copper ores as it is extracted alongside these metals. The primary source of lead metal is sulphide ore, particularly galena (PbS), which contains 86.6% lead content. Other commercially mined lead minerals include cerussite (PbCO3) and anglesite (PbSO4). More than 95% of all lead is derived from these three minerals, but a significant portion is obtained through recycling, particularly from automobile batteries.

Properties of Lead

Lead, represented by the symbol Pb, has several key properties. Its boiling point is approximately 1,740°C, and its melting point is 327.5°C. The colour of solid lead is bluish white, with a density of 11,340 kg/m³ at 20°C. It falls under the classification of metallic elements and is insoluble in water. Lead has an atomic number of 82 and an atomic weight of 207.2 gm (1). It remains stable under ordinary conditions of use and storage.

Lead boasts a bluish-white lustre but forms a dull, grey layer of basic carbonate on exposure to air, protecting it from further oxidation or corrosion. With a low tensile strength and relatively poor electrical conductivity, lead’s face-centred cubic crystalline structure makes it easily cast, joined, and shaped. Its high density makes it suitable for shielding against sound, vibrations, and radiation, commonly used for protecting users of computers and TV screens. Lead is used in metallic form or as lead compounds in lead glasses, providing valuable properties in relation to colour and glass-forming ability.