Its name comes from the Latin “Plumbum”. Plumbum , commonly known as Lead, was present in all the Metal Ages and played an important role in the industrial and scientific progress.
Its properties have made it one of the most used metals in industry in the Greek and Roman eras.
What is plumbum ?
Commonly known as Lead , Plumbum is a chemical element with atomic number 82 and its symbol Pb. It belongs to the 14th Group and 6th period table of elements.
Soft metal,heavy and malleable, bluish-white color is just cut and dark gray when exposed to air.
Generally, it is not found free in nature, but has been known since from the remotest antiquity. It was discovered in ancient times (in Anatolia were found lead beads dating to 6500 BC).
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lead mining in ancient times
The main lead production centers in the ancient world were in Attica (mines of Laurion piomboargentifero), Macedonia, Cyprus, Rhodes, Gaul, Britain (where, according to reports Pliny he produced in such abundance that a law prohibiting more than a certain amount fabricate), in southern Spain, in Africa, in Etruria, in Sardinia, the island of Elba, Capraia, the Balearics, the Cassiteriti islands. The silver-bearing lead mines of Cartagena occupied in Roman times forty thousand slaves. The extraction was done by subjecting long-treating the ore, typically galena, and the metal was then put on the market in bars and ingots, marked by the brand stamped workshop or names of emperors, prosecutors or private. The lead and silver were obtained for the most part from the fusion of galena (Mineral composed of lead sulfide).
The roasting transformed galena, litharge and part in part to lead sulfate, while with the fusion, obtained by increasing the temperature, when it reached the right degree of desulphurisation, the lead was obtained. The treatment was performed in primitive ovens built of clay and stones. In many places of the Roman Empire, such as in Britain, the ovens were built on the hillsides in order to use the prevailing winds for draw. The crude lead, called plumbum, contained from 45 to 80 ounces of silver per ton.
To extract the galena the Romans warmed in a special oven with a jet of hot air to oxidize the lead that was separately below.
This process may be repeated until the silver content does not reach the percentage comprised between 1 and 2 percent. The alloy thus obtained can be so coppellata to obtain the silver, and the litharge formed can again be transferred to the melting furnace.
plumbing in ancient rome
The use of lead was tied in antiquity for different purposes; the coverage of the roofs of houses with lead goes back to ancient times: a notable example was the palace of Constantinople, built by the Emperor Constantine.
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Very old also the use of lead for roof gutters, blacks wells or to schedule blocks of metal to stone.
Because of the resistance to corrosion and due to its flexibility it has been widely used for hydraulic works and construction of buildings and ships.
Its low melting point has made welding material; moreover, in many cultures, alone or as an alloy, it was used to mint coins.
The use of lead in the artistic field was always limited and circumscribed, due to difficulties of processing, mostly of minor crafts.
One of the most important historical applications of lead was the water pipes of Rome. Lead pipes were fabricated in 3-metre (10-foot) lengths and in as many as 15 standard diameters.
Many of these pipes, still in excellent condition, have been uncovered in modern-day Rome and England. The Roman word plumbum, denoting lead water spouts and connectors, is the origin of the English word plumbing and of the element’s symbol, Pb.
is lead dangerous ?
Marcus Vitruvius Pollio, a 1st-century-bce Roman architect and engineer, warned about the use of lead pipes for conveying water, recommending that clay pipes be used instead. Vitruvius also referred in his writing to the poor colour of the workers in lead factories of that day, noting that the fumes from molten lead destroy the “vigour of the blood.”
On the other hand, there were many who believed lead to have favourable medical qualities.
Pliny, a Roman scholar of the 1st century, wrote that lead could be used for the removal of scars, as a liniment, or as an ingredient in plasters for ulcers and the eyes, among other health applications.
how lead was used THROUGHOUT history ?
Many churches and major buildings constructed in the 15th and 16th centuries provide examples of lead employed as a roofing material and for water conveyance. Indeed, the stained-glass windows of many cathedrals and castles of this period were made possible by the use of lead cames that held the glass elements together in a magnificent unity of colours and shapes.
In 1859 a French physicist, Gaston Planté, discovered that pairs of lead oxide and lead metal electrodes, when immersed in a sulfuric acid electrolyte, generated electrical energy and could subsequently be recharged. A series of further technical improvements by other investigators led to commercial production of lead-acid storage batteries by 1889.
The huge growth of battery markets in the 20th century (eventually consuming about 75 percent of the world’s lead production) largely paralleled the rise of the automobile, in which batteries found application for starting, lighting, and ignition.
Another prominent lead product was tetraethyl lead, a gasoline additive invented in 1921 in the United States to solve “knocking” problems that had become commonplace with the development of high-compression engines operating at high temperatures. Soon after reaching its peak 50 years later, the use of this lead compound declined in the United States as the installation of catalytic converters became mandatory on the exhaust systems of all American passenger cars.
By the early 21st century, China was leading the world in both primary and secondary lead refining. Other top lead refiners include the United States, the United Kingdom, Germany, and India.
Info sources: https://en.wikipedia.org/wiki/Lead