henry bessemer was the american who independently discovered the process to remove impurities by blasts of cold air blown through heated iron.
henry bessemer was the american who independently discovered the process to remove impurities by blasts of cold air blown through heated iron.
what american independently discovered  the process to remove impurities by blasts of cold air blown through heated iron?
henry bessemer
throughout the 18th and early 19th centuries, the english steelmakers produced blister and crucible steel which required specialized equipment like finery forges and puddling furnaces and cost over £50 per long ton. in the 18th century, innovations like steamboats, railroads, and guns increased demand for wrought iron and steel. the mount savage iron works in maryland was the largest in the united states in the late 1840s, and the first in the nation to produce heavy rails for the construction of railroads. in the 1850s, american william kelly and englishman henry bessemer independently discovered that air blown through the molten iron increases its temperature by oxidizing the carbon and separating additional impurities into the slag. the kelly-bessemer process, because it reduces the amount of coke needed for blasting and increases the quality of the finished iron, revolutionized the mass production of high-quality steel and facilitated a drastic drop in steel prices and expansion of its availability.
technological and industrial history of the united states
benjamin huntsman was one of the first to begin adding other metals to steel. his process of making crucible steel, invented in 1740, was the first time steel was able to be fully melted in a crucible. huntsman had already been using various fluxes to help remove impurities from steel, and soon began adding a manganese-rich pig-iron called "spiegeleisen", which greatly reduced the presence of impurities in his steel. in 1816, a german researcher carl j. b. karsten noted that adding fairly large amounts of manganese to iron would increase its hardness without affecting its malleability and toughness, but the mix was not homogeneous and the results of the experiment were not considered to be reliable. "and no one understood that the real reason why the iron mined in noricum produced such superb steel lay in the fact that it contained a small amount of manganese uncontaminated by phosphorus, arsenic, or sulphur, and so was the raw material of manganese steel." in 1860, sir henry bessemer, trying to perfect his bessemer process of steel making, found that adding "spiegeleisen" to the steel after it was blown helped to remove excess sulfur and oxygen. sulfur combines with iron to form a sulfide that has a lower melting point than steel, causing weak spots, which prevented hot rolling. manganese is usually added to most modern steels in small amounts because of its powerful ability to remove impurities.
mangalloy