Schematic drawing of a puddling furnace

The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. Pig iron contains high amounts of carbon and other impurities, making it brittle. The puddling furnace burns off these impurities to produce a malleable low-carbon steel. It is the process of manually handling and stirring the iron during and after this process that gives us the name "wrought". Invented by Peter Onions and patented by Henry Cort in 1783–4, the puddling process, along with the blast furnace, led to a massive increase in the amount of iron being produced every year. Schematic drawing of a puddling furnace. ... Schematic drawing of a puddling furnace. ... By the mid 20th century humans had achieved a level of technological mastery sufficient to leave the surface of the planet for the first time and explore space. ... A wrought iron railing in Troy, New York. ... Pig iron is raw iron, the immediate product of smelting iron ore with coke and limestone in a blast furnace. ... Blast furnace diagram A blast furnace is a type of furnace for smelting metal ore. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... A patent is a set of exclusive rights granted by a state to a person for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or composition of matter (substance) (known as an invention) which is new, inventive, and... During the Industrial Revolution in England, Henry Cort began refining iron from pig iron to wrought iron using innovative production systems. ...

The furnace was constructed to pull the hot air over the iron without it coming into direct contact with the fuel, a system generally known as a reverberatory furnace or open-hearth process. After lighting and being brought to a low temperature, the furnace is prepared for use by "fettling", painting the grate and walls around it with iron oxides, typically hematite. Iron is then placed on the grate, normally about 600 lb, and allowed to melt on top, mixing with the oxides. The mixture is then stirred vigorously with a "rabbling-bar", a long iron rod with a hook formed into one end. This causes the oxygen from the oxides to react with impurities in the pig iron, notably silicon, manganese and to some degree sulfur and phosphorus, which form gases and are removed out the chimney. A reverbatory furnace is a metallurgical or process furnace which characteristically isolates the material being processed from contact with the fuel, but not from contact with the combustion gases. ... Hematite (AE) or haematite (BE) is the mineral form of Iron (III) oxide, (Fe2O3), one of several iron oxides. ... The pound is the name of a number of units of mass, all in the range of 300 to 600 grams. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... This article is about the chemical element. ... A chimney is a system for venting hot gases and smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. ...

More fuel is then added and the temperature raised. The iron completely melts and the carbon starts to burn off as well. The carbon dioxide formed in this process causes the slag to "puff up" on top, giving the rabbler a visual indication of the progress of the combustion. As the carbon burns off the melting temperature of the mixture rises, so the furnace has to be continually fed during this process. Eventually the carbon is mostly burned off and the iron forms into a spongy plastic material, indication that the process is complete and the material can be removed. General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... For the Transformers character, see Slag (Transformer). ...

The hook on the end of the bar is then used to pull out large "puddle-balls" of the material, about 40 kg each. These are then hammered using a steam hammer to weld shut internal cracks, while breaking off chunks of impurities. The iron is then re-heated and rolled out into flat bars or round rods. The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... The steam hammer is a power-driven hammer used in forgings. ...

The puddling furnace was also used as the first step in making crucible steel as well (see cementation process). Crucible steel describes a number of different techniques for making steel alloy by slowly heating and cooling iron and carbon (typically in the form of charcoal) in a crucible. ... The cementation process is a obsolete technique for making steel. ...

Both processes, and the puddling furnace, were displaced with the introduction of the Bessemer Process, which produced similar quality steels for a fraction of the cost and time. For comparison, an average size charge for a puddling furnace was 600 lb, for a Bessemer converter it is 15 short tons. Wrought iron was made from the Bessemer Process as well. Bessemer converter, schematic diagram The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron. ... The short ton is a unit of mass equal to 907. ...