Zinc & Lead

• Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but malleable at 100 to 150°C. It is a reasonable conductor of electricity, and burns in air at high red heat with evolution of white clouds of the oxide.
• Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass (a mixture of copper and zinc). A brass dating from between 1400-1000 BCE has been found in Palestine. An alloy containing 87% zinc was found in prehistoric ruins in Transylvania. The smelting of zinc ores with copper was apparently discovered in Cyprus and was used later by the Romans. Metallic zinc was produced in the 13th century in India by reducing calamine (zinc carbonate, ZnCO₃) with organic substances such as wool. The metal was rediscovered later in Europe. William Champion set up a zinc industry in Bristol (England) in the 1740s. Other plants were established a little later in Belgium and Silesia.

Galvanizing is the process by which zinc is metallurgically bonded to steel, thereby giving the steel the most advanced and cost-effective anti-corrosion coating. Galvanized steel is used wherever corrosion is a threat.

The above photograph shows a zinc galvanized auto body and is from Zinkberatung Ingenieurdienste Gmbh. Brass is a family of copper-zinc alloys. The zinc content of brass ranges from 10% to more than 40%. Besides its traditional use for door handles, lighting fixtures and decorative objects, brass is now an increasingly popular material with architects, interior designers and consumers. The strength and fluidity of diecasting alloys based on high purity zinc make them ideal for thousands of diecasting applications, such as household appliances, precision parts for cars, computers and communications equipment.

Information on Lead:

• Lead has been known for ages and is mentioned in Exodus. Alchemists believed lead to be the oldest metal and associated it with the planet Saturn. They spent a lot of time trying to "transmute" lead into gold.
• Its softness and low melting point make lead very easy to handle and fashion. Its high resistance to corrosion makes it ideal for weatherproofing buildings and for equipment used in the manufacture of acids. Lead's high density makes it particularly appropriate as a shield against radiation in the nuclear industry and in hospitals. For the same reason lead is also good at stopping sound waves and so is used to reduce noise from machinery in factories and from engine rooms on ships.
• However, the most important use of lead today is in the lead-acid battery which provides power in numerous situations. The most familiar use of the lead-acid battery is to start our cars and other vehicles, but they are also used to power electric vehicles and to provide emergency power when the electricity fails.
• At least three-quarters of all lead used goes into products which are suitable for recycling. This is why lead has the highest recycling rate of all the common non-ferrous metals.

More information about lead can be found on the Lead Development Association International website: http://www.ldaint.org