问题 问答题 论述题

碱金属循环积聚给高炉生产带来什么害处?防治措施有哪些?

答案

参考答案:

害处有:

(1)气化上升的碱金属在较低温度的炉墙上冷凝,黏结,进而发展成炉瘤。

(2)部分上升的碱金属与焦炭作用,降低焦炭强度,增大焦炭的反应性,也降低焦炭的热强度,导致在下降过程中破损,另外也影响料柱的透气性。

(3)部分碱蒸气与矿石作用,引起料块膨胀和爆裂,对球团矿的影响尢为严重。降低矿石的软熔温度,造成软熔温度带上移和变厚。

(4)进入耐火砖衬,造成膨胀或是炉壳开裂,当在炉缸耐火砖内积累还能造成炉底炉缸烧穿。防治措施有利用炉渣排碱、严格控制碱金属入炉量、选用抗碱侵蚀能力强的耐火材料等。

应用设计题
单项选择题

Many in the Middle East have difficulty in adjusting themselves to the new situation created by the departure of the imperial powers. For the first time in almost 200 years, the rulers and people of the Middle East have to accept the final responsibility for their own affairs, to make their own mistakes and to accept the consequences. This is difficult to internalize, even to perceive, after so long a period. For the entire lifetimes of those who formulate and conduct policy at the present time and of their predecessors for many generations, vital decisions were made elsewhere, ultimate control lay elsewhere, and the principal task of statesmanship and diplomacy was as far as possible to avoid or reduce the dangers of this situation and to exploit such opportunities as it might from time to time offer. It is very difficult to forsake the habits not just of a lifetime but of a whole era of history. The difficulty is much greater when alien cultural, social and economic preeminence continues and even increases, despite the ending of alien political and military domination.

Military and to a growing extent political intervention by the West has indeed ended, but the impact of its science and culture, its technology, amenities and institutions remains and even increases. As in other parts of the non-Western world, this impact has been and will be enormous. In these circumstances, it is natural that Middle Easterners should continue to assume—and proceed on the assumption—that real responsibility and decision still lie elsewhere. In its crudest form, this belief leads to wild and strange conspiracy theories directed against those whom they regard as their enemies—Israel, and more generally the Jews, the United States, and more generally the West. No theory is too absurd to be asserted or too preposterous to be widely and instantly believed. Even among more responsible statesmen and analysts, a similar belief in alien power, albeit in a less crude form, often seems to guide both analysis and policy. Some even go so far as to invite outside intervention, presumable in the belief that only outside powers have the capacity to make and enforce decisions. A case in point is the constant appeal to the United States to involve itself in the Arab Israel conflict, oddly coupled with the repeated accusation of "American imperialism. "

This state of mind is likely to continue for some time, with appeals for support or even intervention to the United States, to Russia and even to the European Union. In time, no doubt, Middle Eastern governments and people will learn how to use this window of opportunity to the best advantage—that is, of course, if the window remains open long enough.

The word "this" in the third sentence of Paragraph 1 refers to()

A. the departure of the imperial powers

B. the final responsibility of the Middle Eastern countries for their own affairs

C.the consequence created by the departure of the imperial powers

D. the fact that the Middle Eastern countries have to be responsible for their own affairs