问题 问答题 简答题

生铁铸块使用什么设备?

答案

参考答案:

高炉炼出的生铁主要是直接以液态用铁水罐运送炼钢厂使用。在炼钢时不需要铁水,冶炼铸造生铁和只有高炉炼铁生产的铁水,需要用铸铁机铸成铁块。大中型炼铁厂都建有专门的铸铁车间,小高炉则将铸铁机建在出铁场上,出铁时直接铸成铁块,极少数小铁厂还有在出铁场上用铁模铸块的。铸铁机是一种倾斜向上装有铁模和链板的循环链带式机,它由一列或两列带有铸铁模的链带(具有传动机构和拉紧装置)、铸铁模喷浆器,冷却铸铁模及生铁块喷水装置等组成。铸铁机分为固定辊轮式(链带沿着装在不动支架上的辊轮运动)和移动辊轮式(辊轮

固定在链环上,链带运行时,辊轮沿导轨运动),现代结构的一般为固定辊轮式。铸入铁水的铁模在向上运行一段距离后(一般为全长的1/3)铁水表面冷凝后,开始喷水冷却(耗水量在1.0~1.5t/t),当链条运行到上端翻转时,已经凝固的铁块脱离铁模,落入运送车上,空链带从铸铁机下面返回,途中由喷浆器向铁模喷一层1~2mm的石灰或混合浆,以防止粘模。

单项选择题

Industrial pollution is not only a problem for the countries of Europe and North America but also an extremely serious problem in some developing countries. For these countries, economic growth is a very important aim. They want to introduce industries, and so they put few controls on the industries which cause pollution.
Cubatao, an industrial town of 85 000 people in Brazil, is an example of the connection between industrial development and pollution. In 1954, Cubatao had no industry. Today it has more than twenty large factories, which produce many pollutants. The people of the town are suffering from the poisonous matter in their environment and the bad effects can be clearly seen. Birth shortcomings are extremely common. Among children and adults, lung problems are sometimes twelve times more common in Cubatao than in other places.
It is true that Brazil, like many other countries, has laws against pollution, but these laws are not enforced strictly enough. It is cheaper for companies to take no notice of the laws and pay the fines than to buy the expensive equipment that will reduce the pollution. It is clear, therefore, that economic growth is more important to the government than to the health of the workers. However, the responsibility does not completely lie with the Brazilian government. The example of Cubatao shows that international companies are not acting in a responsible way either. A number of the factories in the town are owned by large companies from France, Italy, and the US. They are doing things in Brazil that they would not be able to do at home. If they caused the same amount of pollution at home, they would be severely punished or even put out of business.

Why do some foreign companies like to set up their plants in Brazil

A. The investment environment in Brazil is suitable for them.
B. They will not be severely punished if they cause pollution in Brazil.
C. They can make much money because they do not have to pay Brazilian workers much.
D. They can act in an irresponsible way in Brazil because there are no pollution laws there.

多项选择题