Bessemer considered the method of converting cast iron to wrought iron. To do this iron ore was added in carefully measured amounts to cast iron. The mixture was heated to the molten stage and the oxygen atoms in the iron ore would combine with the carbon atoms in the cast iron to form carbon monoxide gas which bubbled out and burned off, leaving pure iron behind.
Was there no other way of adding oxygen to burn off the carbon but in the form of iron ore? Why add the oxygen directly as a blast of air? The objections seemed to be that the cold air would cool and solidify the molten iron and stop the whole process.
Bessemer tried it anyway and found that just the reverse was true. The blast of air burned off the carbon and the heat of that burning not only kept the iron molten but, indeed, raised its temperature so no external source of fuel was needed. By stopping the process at the high time Bessemer found he had steel ready-made without the wrought iron step and without spending money on fuel. Steel could be made at a fraction of its previous cost.
In 1856 he announced his discovery. Ironmakers were enthusiastic and invested fortunes in "blast furnaces". Unfortunately matters went awry. The steel produced was a very poor grade and Bessemer was damned as a charlatan. He returned to his experimentation.
It turned out that in his original experiments he had used phosphorus-free ore, but the ironmakers had used phosphorus – containing ore. The Bessemer method would not work if phosphorus was present. Bessemer announced this, but the ironmakers once bitten were twice shy and would not listen. Bessemer borrowed money, therefore, and put up his own steelworks in Sheffield in 1860. He imported phosphorus-free iron ore from Sweden and began to sell high-grade steel for one-tenth the prices of the competition.
With Bessemer and with those after him, such as Siemens, who improved the steelmaking process even further, began the era of cheap steel. It meant the coming of giant ocean liner, of steel-skeletoned skyscrapers, of huge suspension bridges. Bessemer did not invent steel but he did make it available to everyone.
(from I. Asimov's Biographical Encyclopedia of Science and Technology)
Task 1. Lexical exercises
Exercise 1. Match the words on the left with the meanings on the right.
1. an ore a) a material for producing heat or energy (eg coal, oil)
2. a mixture b) a kind of rock, earth, mineral, etc. from which metal can
be mined or extracted: iron ~
3. a fuel c) to make or to become hot: ~ (up) some water
4. tough d) to make or to become solid, hard or firm
5. hard e) to get something, or its use, on the understanding that it
is to be returned: May I ~ your pen?
6. brittle f) something made by mixing: a cough ~. Air as a ~ of gas-
es
7. to heat g) not easy cut, broken or worn out: as ~ as leather
8. to solidify h) contrasted with soft; firm; not yielding to the touch, not
easily cut; solid: as ~ as rock
9. to cool i ) hard but easily broken (eg. coal, ice, glass)
10. a phosphorus k) to make or become cool: The rain has ~ ed the air
11. to borrow l ) a yellow non-metallic, poisonous element like wax (sym-
bol P) which catches fire easily and gives out a faint light
in the dark
Exercise 2. Match the English words and word-combinations given below with their Russian equivalents.
1. fixedconverter a) кованое железо, пудлинговое железо
2. tilting converter b) в расплавленном состоянии
3. cast iron c) углекислый газ
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