Symbol: Pb
Melting point: 327.5'C
Electron configuration: [Xe]4f145d106s26p2
Atomic number: 82
Atomic mass: 207.2±0.1u


Ore Common Name Formula
Sulphide Galena PbS
Sulphate Anglesite PbSO4
Basic Sulphates Plumbojarosite PbFe6(OH)2(SO4)4
Chlorophosphate Pyromorphite 3Pb3P2O8,PbCl2
Chloroarsenate Mimetite 3Pb3As2O8PbCl2
Chlorovanadate Vanadinite 3Pb3V2O8PbCl2
Chromate Crocosite PbCrO4
Molybdate Wulfenite PbMoO4
Carbonate Cerussite PbCO3

Lead is the heaviest metal in the list of common metals. It is very soft, malleable and ductile. It can be rolled easily. Lead is resistant to corrosion. Many acids have no chemical actions on lead. Because of this character, it is used for water pipes, roof coverings, cable coverings, chemicals and paints. Lead melts at 327'C. Lead is rarely found in native state. Its color is bluish grey. The freshly cut surface shows bright metallic lustre. The surface can be scratched easily. Lead is soluble in nitric acid. Major lead producers of the world are U.S.A, Japan, Russia, Germany, U.K, Canada, Australia, France and India. The countries like Australia, U.S.A, Russia, Canada, Peru, Mexico, South Africa, Morocco, India and Yugoslavia are leading producer lead minerals. The primary ore mineral of lead is Galena. Other important ores are Cerussite and Anglesite. The elements like Zinc and Antimony are associated with lead in ore deposits.

Extraction of Lead

Galena is the most important ore of lead. It contains lead up to 8%. It is always associated with Sphalerite, that is an ore of zinc. The ore of lead is crushed and cleaned by washing. The cleaned ore is concentrated by froath-floatation process. The concentrated ore is separated and dried properly. The ore concentrate is roasted in a reverberatory furnace at moderate temperature. Air is supplied into the furnace during the roasting.

2PbS + SO2 -> 2PbO + 2SO2
PbS + 2O2 -> PbSO4
2PbS + 3O2 -> 2PbO + 2SO2

After the roasting is over, air supply is stopped. Some amount of Galena concentrate is added to the roasted ore. The temperature is increased and the air supply starts. Lead sulphide reacts with Lead Oxide and Lead Sulphate to produce lead metal.

2PbO + PbS -> 3Pb + SO2
PbSO4 + PbS -> 2Pb + 2SO2

The molten metal is collected at the bottom of the furnace. It is separated into ladles and converted into metal castings.