Knowledge

Lead

Lead is one of the chemical elements known by the symbol pb, which has the atomic number 82. Lead is found in nature in the form of a mineral called galena. Shiny / flexible / very soft / highly malleable metal lead with low electrical conductivity and heavy and toxic element with a dull gray color. This real metal is highly resistant to decay and is therefore used to store corrosive liquids (such as sulfuric acid). It can be hardened by adding small amounts of antimony or other metals to lead. This metal has the most applications after iron, aluminum, copper and zinc. When freshly shaved, the lead is bluish white but turns dark gray when exposed to air. Lead is used in building structures, lead acid capacitors, bullets and pellets, and is also part of solder, pewter and fusible alloys. Lead is the heaviest stable element that alloys with many metals. Alloys made of tin, copper, arsenic, antimony, bismuth, cadmium and sodium are all of great industrial importance. applications Primary applications of lead include: building structures, pigments used in ceramic glazes, and water pipes. Typical applications of lead include: in lead-acid batteries, in electronic components, cable sheaths, ammunition, ceramics, leaded glass, lead pipes The most important applications of lead metal are: The main ingredient in lead-acid batteries is lead, which is widely used in car batteries. These batteries use lead alone or lead with another metal, usually antimony. Lead sheets are used to prevent water intrusion, insulation, roofing and metal cladding in construction, and its high density makes it an effective material for sound insulation applications, and lead-bearing steel for radiation protection. Used. Lead pipes are used to transport corrosive chemicals in chemical plants due to their corrosion resistance properties. Lead has been widely used in the paint industry, white lead is the most widely used as lead pigment, and other important pigments include base lead sulfate and lead chromate. Due to their high ductility, relatively low temperature and corrosion resistance, lead alloys are used as cover materials for high voltage cables in various environments including industrial, marine, soil and chemical materials. Lead is used to make bearings, solders and anti-friction metals. Soft soldering is mainly done with lead-tin alloys with or without antimony. One of the major applications of this metal is in computers and televisions, which protects the viewer’s eyes from radiation. Features of lead metal High flexibility and ductility Corrosion resistant Low melting temperature Very high density Abundance of metal Method of production of lead metal Currently, more than 75% of the world’s lead is produced this way. Lead production is done in the following three steps: Zinter and clearing stage At this stage, the lead concentrate is heated so that the sulfur compounds are mainly converted to lead oxide and volatiles and unstable compounds are removed from the concentrate. Melting and reduction stage At this stage, the purified concentrate with the help of melting and coking aids enters the blast furnace and is formed by blowing oxygen and heating regenerating gases and converting various lead compounds to pure lead. Lead enters the molten phase and impurities go into the slag with the overhead of the structures. Purification stage The lead grade from the blast furnace is about 97%. To increase the grade to 99.9%, at this stage impurities such as Zn; Cd; Ag; Cu are removed. Applications Manufacture of pipes and water tanks, roofing, tin, wire, power cable sheathing, ammunition and weapons, glass, plastic, battery, rubber, metal alloys, paint, matches, chemical industry, Lead chambers, evaporation sources, pesticides, car fuel and printing letters, fittings and dental fillings. In 2014, lead production worldwide increased due to the use of lead-acid batteries. There are two different production categories for lead: primary production from minerals and secondary production from scrap metal. In 2014, 4.58 million tons of lead were generated from primary production and 5.64 million tons from secondary production. The top three producers of lead concentrate extracted that year were China, Australia and the United States, respectively. [2] The top three producers of refined lead were China, the United States and India. [2] Primary and secondary lead production processes are similar. Some primary production plants are now completing their operations with lead scrap, and this trend is likely to increase in the future. If appropriate methods are used, lead obtained through secondary processes cannot be detected from lead obtained through primary processes. Scrap lead from the building construction industry is usually relatively clean and re-melted without the need for smelting, although some refinement is required; Therefore, secondary lead production is cheaper than primary production in terms of energy requirements by nearly 50% or more. [3] Although lead metal is not used in many previous applications today, this non-corrosive metal is actually very useful in products that retain highly acidic materials. For example, lead is used to make tanks that contain corrosive liquids such as sulfuric acid. They are also used to make lead acid batteries

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