英文科學(xué)讀本 第二冊(cè)·Lesson 22 Iron Ore

Lesson 22 Iron Ore

Do you know, Norah, said Willie, "which is the best of all the metals?"

I should think gold is the best, said his sister; "it is worth so much money, and is so bright and beautiful."

No, said Will, "gold is not the best metal. Iron is the best, because it is so useful. Teacher says it is the King of Metals. We see more things made of iron than of any other metal. Here comes Fred. Suppose we have a chat about iron now."

All right, said Fred, "I'm ready. Where did this iron poker come from at first, Norah?"

The iron was dug out of great pits in the earth, called mines, said Norah. "That is why we say iron is a mineral."

That's right, said Fred, "but the iron was then only like a rough stone. It was called iron-ore or iron-stone. Much has to be done to make it fit for use.

The iron-stone is first mixed with coal, and piled in great heaps in the open air. The heaps are set on fire and left to burn for days. This is called roasting the ore. It burns away the sulphur and some of the other useless parts of the ore. The roasted iron-stone is next put into the blast furnace. This great furnace is made of solid stone and brick work, built in the form of a cone or sugar-loaf. Just think of a great sugar-loaf seventy feet high, Norah.

Teacher showed us a picture of a blast Furnace, said Will. "It was so easy to understand all about it from the picture. It looked as if the great furnace had been cut down through the middle, from the top of the cone to the ground.

There was a gallery all round the top, and we could see the men on the gallery wheeling barrows filled with iron-stone and fuel. The furnace is always fed from the top. Every half hour the men throw in their barrow-loads of iron-ore, coke, and lime. The furnace burns day and night, and is never once allowed to go out for years.

I suppose the great heat melts the iron in the ore, said Norah, "for iron is fusible."

Quite right, little sister, said Fred, "and the melted iron sinks to the bottom of the furnace, because it is heavier than the other substances."

SUMMARY

Iron is the "king of metals." Iron-stone or iron-ore is dug out of the earth. It is first mixed with coal, and roasted in great heaps. Then it is smelted in the blast furnace with coal, coke, and lime. The enormous heat melts the iron of the ore, and it sinks to the bottom of the furnace as a thick, red-hot liquid. All the useless parts of the ore float on the top of the liquid iron.