Patrick Raether, age 13, of Springfield, Ill., for his question:
HOW IS LEAD USED?
Lead is a metallic element that is widely used in many different ways. It is one of man's most versatile products. And the great weight of lead adds to its usefulness.
Because lead is resistant to many acids, it is used to line the inside of chemical storage tanks. It is also still occasionally used to make water pipes.
Once the face of the lead is tarnished by the action of air, it is safe from all further oxidation. For this reason, lead is useful as a protective covering for telephone and other kinds of cables.
Lead is used for sinkers on fishing nets. And it is also used to make small sinkers for fly casting fishermen.
Lead weights or sounds are used to measure the depth of the ocean. Also, the suits and shoes used by deep sea divers are weighted with lead.
An automobile storage battery uses lots of lead. The battery plates are made from antimony hardened lead.
Lead and lead compounds are used to make medicines and ointments. A doctor will have to prescribe just which lead containing products may be useful in improving your health, if any are needed.
Solder is an easily melted alloy of tin and lead that sticks to all metals except aluminum. This item is one of the most useful in the home workshop.
Lead mixed with tin and a bit of the metal antimony becomes the fine product pewter. Pewter was a popular 18th century product and it is still used today to make classic tableware of great beauty.
Lead monoxide is used to make cut glass, imitation diamonds and pottery glazes.
Lead is used as a shield against the rays given off by radioactive substances. Its great density stops the rays before they can do any harm. Vests of lead are used by X ray technicians.
The principal source of lead is lead sulfide ore, or galena. Lead is also often found in nature mixed with the sulfides of zinc, copper, iron and silver.
Leading lead producing countries of the world are the United States, Canada, Mexico, Australia, the U.S.S.R. and Germany. The most important U.S. lead mines are found in southeastern Missouri, Idaho, Utah, Arizona, Oklahoma, Colorado and Montana.
Metallic lead is taken from various ores by smelting in a blast furnace. After the ore is crushed, it is roasted to drive off any sulfur. The roasted ore goes into a tall furnace with limestone and a small amount of coke for fuel. Compressed air enters from the bottom to keep the coke burning. The hot gases from the burning coke mix with the lead ore, setting free the metallic lead. The lead is drawn off at the bottom.
About 50 percent of the world's lead production is used in the United States. And almost one third of the entire U.S. needs are met by reclaiming the lead from worn out storage batteries.