Iron - Smelting without Charcoal

The First Blast Furnaces

 

So far, no furnace in Europe had been hot enough to melt iron to a liquid state. All that could be produced was a ‘spongy’ mass from which impurities had to be hammered out. However, design of furnaces improved over the centuries, and about the year 1400 very efficient blast furnaces were introduced by the Germans. They had found that a blast of air from water-powered bellows increased the temperature, though the iron still did not liquify. It became soft and spongy, worked its way down through the burning charcoal, and collected at the bottom of the furnace.

Furnaces were usually built about ten or fifteen feet high, but to economise on fuel a new one was built thirty feet high. Although the internal temperature in this was no higher, the iron arrived at the bottom in a completely liquid state. Not only could the metal be run off into moulds, but many of the impurities (which had previously to be hammered out) separated automatically from the melted iron. The reason for this tremendous stride in metallurgy was simple: the height of the furnace. The soft ‘sponge’ iron took so long to seep down through the charcoal that it absorbed a great deal of carbon. It became carburised, and as the melting point of carburised iron is 350^o C less than ‘sponge’ iron, it became liquid.

By about the year 1600, iron production in Britain was beginning to suffer from lack of fuel. For 3,000 years all iron-smelting, both here and abroad, had been done with charcoal. Charcoal is partly-burned wood. In Britain, timber was running short and it was impossible for the iron-makers to equal the output of a country such as Sweden, where timber was abundant.

Fortunately for Britain a Quaker, Abraham Darby, found a way to do without charcoal altogether. In his iron factory at Coalbrookdale, Shropshire, he made many experiments using coke, and finally succeeded. There were technical difficulties to overcome, and at first Darby kept the process secret for the benefit of his family. Later his methods were adopted throughout Europe. No longer dependant on dwindling forests, Britain remained her position as a leading iron producer.

Task 1.

Phonetic Exercise

Practise after the speaker and learn to pronounce the words given below.

 

liquid /’likwid/; spongy /’sponji/; design /di’zain/; liquify /likwi’fai/; automatically /o:t'‘mжtik'li/; metallurgy /’metl':ji/; carburised /’ka:bjuraizd/; technical /’teknik'l/; throughout / q ru’aut/.

 

Task 2.

Lexical Exercises

Exercise 1. Find the English equivalents for the words and word -

combinations given below.

 

примеси; доменная печь; поток воздуха; жидкое состояние; высотой в десять футов; экономить на топливе; температура внутри печи; большой прогресс в металлургии; поглощать углерод; недостаток топлива; кокс; преуспеть в ч-л; проводить опыты; преодолевать трудности; по всей Европе; воостановить свои позиции.

 

Exercise 2. Match the English words and word-combinations given

below with their Russian equivalents.

 

1. to melt iron to a liquid state 1.удалить примеси

2. to hammer out impurities 2. отделять от

3. efficient blast furnaces 3. точка плавления

4. at the bottom of the furnace 4. сравнять результаты

5. to separate from 5. расплавить железо до жидкого

состояния

6. melting point 6. быть в изобилии

7. to equal the output 7. на благо. ради

8. to be abundant 8. на дне печи

9. for the benefit of 9. высокопроизводительные

доменные печи

Exercise 3. Answer the following questions:

 

1. When did the first blast furnaces appear? 2. What is the work of a blast furnace based on? 3. Does the productivity of blast furnaces depend on their height? 4. Why did iron production in Britain begin to suffer? 5. What did Abraham Darby introduce into the process of iron-making?

 

Exercise 4. Complete the following statements by choosing the answer

which you think fits best. Are the other answers unsuitable?

Why?

 

1. No furnace in Europe could melt iron to a liquid state because:

a) there were too many impurities in it.

b) they were not hot enough.

c) water-powered bellows didn’t work properly.

2. The reason for the tremendous stride in metallurgy was:

a) the height of the furnace.

b) the shape of the furnace.

c) the internal temperature of the furnace.

3. Iron production in Britain began to suffer from:

a) the exhaustion of the deposits of iron ore.

b) political situation.

c)lack of fuel.

4. Abraham Darby succeeded in his experiments to do without charcoal

because:

a) he used coke.

b) he hammered out the impurities.

c) he mixed iron with carbon.

 

Exercise 5. Give a written Russian translation of the following passage.

 

1. In addition the rapid developments in the use of iron and steel during the Industrial Age brought with them greatly increased demand for other metals, particularly copper, tin and lead. Moreover, the demand was not only for greater tonnages but also for a far greater variety of metals. Many of these metals were one hundred years ago little known names in the periodic table, but have now come into prominence and have become marketable commodities. It is accordingly not surprising that there have been more notable advances in metallurgy during the century under review than in the whole history of this ancient art.

 

2. Limestone is included in the furnace because it mixes and combines with sand, clay and stones in the ore. They form a waste material, called slag, which floats on top of the molten metal.

 

 

Task 3.

Focus on Grammar