How the Bessemer Process Works
The Bessemer process works by putting pig iron or wrought iron - iron with many impurities - into a compartment in a large machine called a Bessemer furnace - sometimes known as a blast furnace - which blows air under the converter, under the iron. The air is thrust into a fire set up under the converter. When the flame hits the cold air, the air reaches 3000 degrees Fahrenheit. The heat pulls out all the impurities from the iron, and leaves 99.445% iron, which is the amount of iron in steel. The rest are impurities: 0.294% carbon, 0.014% phosphorous, 0.199% manganese, 0.105% copper, and 0.033% silicon. Because the Bessemer converter could pull out so much of the impurities, found in the iron, the steel was stronger.
“Experts estimate that 2,000,000 tons of steel will be made in Europe and 1,000,000 tons in England at a cost of £30,000,000, whereas, under the old process, it would have cost £150,000,000."
Bessemer Steel,
New York Times, Oct 17, 1880
This was a big step forward because the Bessemer process could make 5 tons of steel in 20-30 minutes. Before that, many industries used wrought iron which was carbon-free, and just add carbon to make steel. However, this process was expensive, and took 10-14 days to make 40 to 50 pounds of steel, which is why the Bessemer process came as such a relief to many industries and businesses.
"By the end of the nineteenth century, world production of steel was approaching 30 million tons, some five hundred times what it had been barely a half-century before, and almost totally supplanting the production of iron, which had slipped to 16% of the volume of its new cousin."
Meet You In Hell: Andrew Carnegie, Henry Clay Frick, and the Bitter Partnership that changed America,
Les Standiford, 2005
"Between 1880 and 1900 U.S. steel production increased from 1.25 million tons to more than 10 million tons."
Steel Industry
Gale Encyclopedia of US Economic History
All photos are courtesy of www.banklands.com