In the earth's crust of lead (Plumbum, Pb) contains 0.0016%. It is practically never found in its pure form — it is mainly part of various ores, of which there are more than a hundred today. The most common of these is galena — lead sulfide (PbS) — the main source of lead in the world. It is mainly produced in the United States, Russia, Canada, Australia and Mexico. Galena is also presumably present on Venus, together with bismuth sulfide, forming the surface layer of some elevations.
The following minerals are less common than lead sulfide:
In addition to lead itself, lead ores also contain other metals, including noble ones (gold, silver). It is believed that the combination of these elements was the impetus for the development of lead metallurgy. To purify precious metals from impurities, they were alloyed with lead and calcined at high temperatures. During the roasting process, lead and other impurities were oxidized. The resulting compounds were blown away by a stream of air — a bar of refined gold or silver remained at the bottom of the melting furnace.
Lead smelting was one of the first metallurgical processes known to mankind. As early as the 4th millennium BC, lead was used to cast sculptures, make medallions and leads, and mint money. In ancient Egypt, lead was used as a cosmetic product: black lead sulfide was used for eyeliner, and a mixture of lead oxide and slaked lime was used to give hair a blue-black color.
Lead was most actively used in the pre-industrial world in ancient Rome. At that time, this metal was mined up to 80,000 tons per year and was carried out in Central Europe, Greece, Spain and Roman Britain. Lead was mainly used to build an inexpensive and reliable pipeline in Rome and adjacent provincial cities. It was also used in cosmetology in the production of powders, blush and mascara, as condiments and preservatives in cooking and winemaking, for making lead, bronze and brass coins and for counterfeiting silver and gold banknotes.
Modern industry uses tens of millions of tons of lead per year, but this is not always new smelted metal. More than 90% of lead products are recycled. And the better a country collects this metal, the more recyclable materials cover production needs. For example, in the US, only 20% of the lead used is a new metal; in the EU, this figure reaches 40%.
Today, 80% of all lead, both recyclable materials and new metal, is used for the manufacture of batteries, including for alternative energy systems. Their production is much cheaper than lithium batteries, and lead batteries themselves have a significantly longer life span: at operating temperatures from 38°C to 42°C, after 3,000 operating cycles, the capacity of the lead battery decreases by only 10%, and the estimated service life is 15-20 years, which corresponds to the minimum period of operation of solar panels.
The second place in the industrial use of lead is rolled steel: for manufacture cold-rolled belts, sheets and pipes consume approximately 6% of all metal used. 5% of lead is used to make pigments, including lead murik, a material used to paint the underwater part of ships and protects iron from corrosion. 3% is used to produce explosives, shells, shots and bullets, 2% to smelt various steels and alloys, including precision, 1% — for the manufacture of cable sheaths. The remaining 3% are used in crystal smelting and manufacturing products for protection against electromagnetic radiation: protective suits, lining elements for X-ray rooms and nuclear reactors.
One of the most common heavy metal poisoning in the world is lead poisoning. But this became known relatively recently. Back in the 70-80s of the last century, lead was actively used as an additive for gasoline, using it to increase the octane number of fuel. During the combustion of fuel, lead particles entered the atmosphere, thereby polluting it. When inhaling polluted air, the substance accumulated in the body, which led to chronic intoxication. The lesions affected all parts of the brain and peripheral nervous system; muscle and circulatory system function were impaired.
Historians also attribute some of the diseases of the Russian tsars to lead poisoning. Built in the Moscow Kremlin in 1633, the water supply system was made entirely of lead. According to scientists, he was the cause of death for most of the children of Tsar Alexei Mikhailovich the Quiet (Peter I's father). The “poisoned” water supply system lasted just over a hundred years and was destroyed during the Troitsk Fire at the end of May 1737.
Today, they are trying to limit the use of lead in the world by replacing it with alternative metals, tightening the requirements for the disposal of lead products and increasing control over industrial safety. But so far, about 0.5 million tons of this toxic substance enter the world's oceans every year. Fortunately, the low solubility of lead compounds prevents the accumulation of large amounts of metal in water: in the oceans, the lead concentration does not exceed 0.03 μg/liter, which corresponds to the maximum allowable concentration of this substance established by environmentalists.
