书城外语英国学生科学读本
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第65章 红色金属--铜

1.There is only one metal which is red in colour.Its name is copper.On the shores of Lake Superior in North America,lumps of pure copper are found in the rocks;but in Cornwall①,and in Australia,and in many other places,we find copper as an ore②.

COPPER ORE(铜矿石)

2.An ore is a metal united with one or two other substances.Copper ore looks like a stone of a black,or a green,or a red colour.Looking at a lump of the ore,no one would think that there was any copper in it.

①Cornwall,a county in the southwest of England.

②Ore,metal mixed with other substances,as it is dug from the earth.

3.The other substances which are combined①with the copper to form the stony-looking ore are sulphur②,iron,and oxygen③.These substances are got rid of by first roasting the ore in a furnace④,and then smelting or melting it in a much hotter furnace.This is repeated⑤three times,until at last the pure copper is left by itself.

4.The smelting of copper ore is chiefly carried on in the town of Swansea,in South Wales,to which port ships bring copper ore from all parts of the world.

SECTION OF A COPPER MINE,CORNWALL.(康沃尔,铜矿一角)5.Copper can be rolled or hammered out into thin sheets,and so we say that it is malleable.It can also be easily drawn out into wire,and for this reason we call it ductile.Sheet copper is much①Combined,united;joined together.

②Sulphur,a yellow mineral substance.

③Oxygen,a gas,forming part of the air,which supports life and flame.

④Furnace,a close fire-place for melting metals,etc.

⑤Repeated,done over again.

used for covering the bottoms of ships,and for making kettles and saucepans and many other household articles.

6.Copper is a good conductor of electricity①-thatis,it allows electricity to pass along it very easily.When electric lights or electric bells are put up,copper wire is always used.The cables②which are placed on the bottom of the sea to carry telegraph messages from one country to another have copper wires running through them.

7.Copper does not rust or tarnish so quickly as iron when exposed to the air.But if we heat a piece of sheet copper in a clear fire,we shall find that the surface turns black,from the copper rust which forms all over it.

8.Copper is harder than lead,for we cannotscratch it with our finger-nail as we can scratch lead.

TELEGRAPH CABLE

(电报线缆)

But it is not so hard as iron,for it is easily scratched by an iron nail.Copper takes on a fine polish,and the surface of a piece of clean and polished copper is very bright.

SUMMARY

Copper is generally found mixed with other substances,which are got rid of by first roasting and then smelting the ore.Copper ore is brought from all parts of the world to Swansea to be smelted.Copper is malleable and ductile.It is harder than lead,but not so hard as iron.Sheet copper is used for sheathing the bottoms of ships and for making household utensils.Telegraph cables are made with copper wire.

①Electricity,an unseen force possessed by certain substances.

②Cables,ropes made of iron wires.

【中文阅读】

1.世界上只有一种红色金属,它的名字就叫做铜①。在北美苏必利尔湖岸边的岩石中,人们可以看到成块的纯铜。然而,无论是在康沃尔、澳大利亚还是其他众多地区,铜都以矿石的形式存在。

2.某种金属与其他一种或两种物质结合在一起便形成了矿石。铜矿石看起来就是一块黑色、绿色或红色的石头。无论是谁,看到一块铜矿石的话都不会想到其中有铜。

3.与铜结合并形成矿石的其他物质包括硫、铁、氧。去除这些物质的方法是:首先将矿石在熔炉中进行加热,然后再将其放入到温度更高的熔炉之中进行融化。这样的流程需要重复三次,直到最后剩下纯铜②。

4.铜矿的炼化主要在威尔士南部的斯旺西③进行,来自世界各地的铜矿用轮船送到这个港口。

5.经过碾压与捶打,人们就可以把铜制成薄片。因此,我们说,这种金属具有可锻性。通过拉伸,人们就可以获得铜线,因此我们说铜具有延展性④。铜片可以用于覆盖船底以及制造水壶、炖锅与其他居家物品。

6.铜是很好的导电介质,也就是说,电流可以轻易通过这种金属。人们在电灯与电铃中总会使用到铜线。用于在不同国家之间传送电报信息的海底电缆⑤也使用到了铜线。

7.与铁相比,如果暴露在空气之中,铜并不会那么快生锈与褪色。然而,如果我们使用明火对铜片进行加热,那么就会发现其表面从铜锈⑥处开始变黑。

8.铜的硬度比铅要高,因为与铅不同,我们无法用指甲在铜的表面刮出痕迹。不过它的硬度又比不上铁,因为我们可以用铁钉轻松地在铜的表面留下刮痕。铜的抛光性很好,一块经过抛光的纯铜表面能够呈现明亮的光泽。⑦译注①铜:铜的颜色也可以称作紫红色。苏必利尔湖(Lake Superior)是世界上最大的淡水湖,1622年为法国探险家发现,湖名取自法语,意为“上湖”,为美国和加拿大共有。这里的纯铜矿是世界上最大的纯铜矿区。纯铜也叫自然铜,在世界其他一些地区也有分布,但最多的还是矿石。古人在7000年前就开始利用自然铜,冶炼铜矿石的技术是很久以后才出现的。全世界铜矿最丰富的国家是智利。中国有不少著名的铜矿,如安徽铜陵、江西德兴等。

②炼铜:现代冶炼的主要方法是“火法冶炼”,流程是:选矿--用“造锍熔炼”得到冰铜--用“吹炼”得到粗铜--用“氧化精炼”得到高纯度的电解铜。这种方法简便易行,但会造成二氧化硫污染。后来又出现了“湿法冶炼”,可以大大降低冶炼成本,正在逐步推广。

③斯旺西:斯旺西(Swansea)英文意为“天鹅之海”,既是重工业基地,也是旅游胜地。19世纪,斯旺西曾经是英国著名的有色金属(铁、锰、铬以外的金属)冶炼中心,炼铜业尤其有名。此外,斯旺西也是铜的贸易市场。

④可锻性、延展性:“有可锻性”的英语是malleable,“有延展性”的英语是ductile。铜在船底用作防腐蚀的材料。

⑤海底电缆:全世界第一条海底通信电缆1850年敷设在英国和法国之间,1866年又成功敷设了一条横贯大西洋的电缆。安徒生在1871年专门为它写了一篇童话《大海蟒》(The Great Sea Serpent)。中国在1871年也由丹麦“大北电报公司”敷设了一条从海参崴通到上海的电缆。现在的海底通信电缆的材料,除了铜,还用上了光纤。

⑥铜锈:铜生锈是铜和空气中的水、氧气、二氧化碳共同反应的结果。铜锈俗称铜绿,学名是“碱式碳酸铜”,有毒,相信不少读者都在铜制的眼镜架上见过。铜绿遇热会分解成黑色的氧化铜,还有二氧化碳和水。

⑦铜镜:因为铜的抛光效果极好,所以古人一直用铜当作镜子。这里还有一件搞笑的事:我小时候曾经寻思过,为什么书上的铜镜都看不见镜子在哪儿。后来才明白,照片拍的是铜镜背面的花纹,正面是光亮的,要是拍正面,非拍出照相机的影子不可。

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