A bloomery is a type of furnace once widely used for smelting iron from its oxides. A furnace is a device used for Heating The name derives from Latin fornax, Oven. Chemical reduction, or smelting, is a form of Extractive metallurgy. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Altogether there are sixteen known Iron Oxides and oxyhydroxides The bloomery was the earliest form of smelter capable of smelting iron. A bloomery's product is a porous mass of iron and slag called a bloom. Slag is the By-product of Smelting Ore to purify Metals They can be considered to be a mixture of metal Oxides however This mix of slag and iron in the bloom is termed sponge iron, which is usually consolidated (shingled) and further forged into wrought iron. Sponge iron is the product created when Iron ore is reduced to metallic Iron, usually with some kind of Carbon ( Charcoal, etc at Shingling was a stage in the production of bar iron or Steel, in the finery and puddling processes A forge is the workplace of a smith or a Blacksmith. A forge is sometimes referred to as a smithy. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron. The bloomery has now largely been superseded by the blast furnace, which produces pig iron. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux

Structure and process

A bloomery consists of a pit or chimney with heat-resistant walls made of earth, clay, or stone. A chimney is a system for venting hot Flue gases or Smoke from a Boiler, Stove, Furnace or Fireplace to the outside Near the bottom, one or more clay pipes enter through the side walls. These pipes, called tuyères, allow air to enter the furnace, either by natural draft, or forced with a bellows. A tuyere is a Tube, Nozzle or Pipe through which Air is blown into a Furnace or Hearth. A bellows is a device for delivering pressurized Air in a controlled quantity to a controlled location An opening at the bottom of the bloomery may be used to remove the bloom, or the bloomery can be tipped over and the bloom removed from the top.

The first step taken before the bloomery can be used is the preparation of the charcoal and the iron ore. Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted The charcoal is produced by heating wood to produce the nearly pure carbon fuel needed for the refining process. The ore is broken into small pieces and roasted in a fire to remove any moisture in the ore. Any large impurities in the ore can be crushed and removed. Since slag from previous blooms may have a high iron content, slag from previous blooms can be broken up and recycled into the bloomery with the new ore.

In operation, the bloomery is preheated by burning charcoal, and once hot, iron ore and additional charcoal are introduced through the top, in a roughly one to one ratio. Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted Inside the furnace, carbon monoxide from the incomplete combustion of the charcoal reduces the iron oxides in the ore to metallic iron, without melting the ore; this allows the bloomery to operate at lower temperatures than the melting temperature of the ore. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state As the desired product of a bloomery is iron which is easily forgeable, nearly pure, and with a low carbon content, the temperature and ratio of charcoal to iron ore must be carefully controlled to keep the iron from absorbing too much carbon and thus become unforgeable. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Limestone can also be added to the charge (about 10% of the ore weight) as a flux, to remove impurities. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 In Metallurgy, a flux is a chemical cleaning agent which facilitates Soldering, Brazing, and Welding by removing Oxidation from

The small particles of iron produced in this way fall to the bottom of the furnace and become welded together to form a spongy mass of the bloom. The bottom of the furnace also fills with molten slag, often consisting of fayalite, a compound of silicon, oxygen and iron mixed with other impurities from the ore. Fayalite (Fe2SiO4 is the Iron rich end-member of the Olivine solid-solution series Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Because the bloom is highly porous, and its open spaces are full of slag, the bloom must later be reheated and beaten with a hammer to drive the molten slag out of it. Iron treated this way is said to be wrought, and the resulting nearly pure iron wrought iron. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron.

History

See also: Early iron smelting

Iron appears to have been smelted in the west as early as 3000 BC, but bronze smiths, not being familiar with iron, did not put it to use until much later. Chemical reduction, or smelting, is a form of Extractive metallurgy. The 30th century BC is a Century which lasted from the year 3000 BC to 2901 BC In the west, iron began to be used around 1200 BC, presumably as a replacement for bronze, which was becoming harder to come by due to shortages in copper and tin. Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50

The onset of the Iron Age in most parts of the world coincides with the first widespread use of the bloomery. This article is about the archaeological period known as the Iron Age for the mythological Iron Age see Ages of Man. While earlier examples of iron are found, their high nickel content indicates that this is meteoric iron. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Other early samples of iron may have been produced by accidental introduction of iron ore in bronze smelting operations. Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus

China has long been considered the exception: by 5th century BC, metalworkers in the southern state of Wu had invented the blast furnace, and the means to both cast iron and to decarburize the carbon-rich pig iron produced in a blast furnace to a low-carbon, wrought iron-like material. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National The 5th century BC started the first day of 500 BC and ended the last day of 401 BC. Wu (吳 was a state during the Spring and Autumn Period in China. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux It was thought that the Chinese skipped the bloomery process completely, starting with the blast furnace and the finery forge to get wrought iron. Iron tapped from the Blast furnace is Pig iron, and contains significant amounts of Carbon and Silicon. Recent evidence, however, shows that bloomeries were used earlier in China, migrating in from the west as early as 800 BC, before being supplanted by the locally developed blast furnace.

Early bloomeries were relatively small, smelting less than 1 kg of iron with each firing. Medieval Europe saw the construction of progressively larger bloomeries, leveling off at around 15 kg on average, though exceptions did exist. The use of waterwheels to power the bellows allowed the bloomery to become larger and hotter; European average bloom sizes quickly rose to 300 kg, where they leveled off through the demise of the bloomery. A water wheel is a means of extracting power from the flow (or fall of water otherwise known as Hydropower. Water powered bellows and larger bloomeries also increased the heat to the point where the iron could melt; this was not considered desirable because it allowed carbon to diffuse into the molten iron, producing unworkable pig iron. Molten iron was not desirable until the advent of the blast furnace.

In England and Wales, despite the arrival of the blast furnace in the Weald in about 1491, bloomery forges (probably using water-power for a hammer as well as the bellows) were operating in the west Midland region beyond 1580. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland The Weald (wɪəld is the name given to a physiographic area in south-east England situated between the parallel Chalk Escarpments of the North In Furness and Cumberland, they operated into the early 17th century and the last one in England (near Garstang) did not close until about 1770. Furness (ˈfɘˑnəs is a Peninsula in the southern part of Cumbria, in north-west England. Cumberland is one of the 39 Historic counties of England. It formed an administrative county from 1889 to 1974 (excluding Carlisle from 1915 and now forms part of As a means of recording the passage of Time, the 17th Century was that Century which lasted from 1601 - 1700 in the Gregorian calendar Garstang is a town parish within the Wyre borough of Lancashire, England. Year 1770 ( MDCCLXX) was a Common year starting on Monday (see link for calendar of the Gregorian calendar (or a Common year starting on Friday ^[1] It survived in Spain and southern France as Catalan Forges to the mid 19th century, in Austria as the stuckofen to 1775. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. This article is about the country For a topic outline on this subject see List of basic France topics. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Austria (Österreich ( officially the Republic of Austria (Republik Österreich In Adirondacks, New York, new bloomeries using the hot blast technique were built in the 19th century. The Adirondack Mountains are a Mountain range located in the northeastern part of New York, that runs through Clinton, Essex, Franklin New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous Hot blast refers to the preheating of air blown into a Blast furnace or other metallurgical process The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar ^[2]

References

External links

• Technology and archaeology of the earliest iron smelting and smithing
• Rockbridge bloomery
• WIRG experimental bloomery
• Precursors of the blast furnace
• Roger Smith's article on bloomery construction
• How Stuff Works
• The Smelter's Art Experimental Iron Production at The Rockbridge Bloomery
• Early use of iron in China