问题 问答题 简答题

高铝和高铁配料方案在立窑煅烧中有何特点?

答案

参考答案:

立窑配料有高铝阿利特和高铁阿利特之分。所谓高铝阿利特方案,即熟料中Al2O3含量较高,相应铝率较高,C3A含量也较高。而高铁阿利特方案,则熟料中Fe2O3含量较高,铝率较低,C4AF含量较多。通常熟料中Al2O3含量大于6.5%称为高铝配料,

熟料中Fe2O3含量大于4.5%称高铁配料。高铝方案有熟料早期强度高,底火较结实,

并容易稳定,烧成温度较宽等优点,但有增强熟料液相粘度和在较低温度下液相较大,以及卡窑、炼边及结窑事故不容易处理等缺点。

采用高铁方案时,由于Fe2O3含量增加,可增加熟料的早期液相和降低液相粘度,

但烧成温度变窄,易结大块且底火较脆弱,同时被CO还原的FeO含量也随之增多,使FeO的危害加剧。当铁含量高时,中部高温层受上部料层压力而变形时间长,变形量大,使中部料层基本上处于低温煅烧,没有达到高温就进入十分缓慢的冷却过程,因而造成C3S的分解,使质量下降。

对于机械立窑,当煤的热值高,灰分较低,操作水平较高,风机的风压较高时,可采用高铝方案。而普通立窑如煤质较差,采用高铝方案就难以使煅烧正常,宜采用高铁方案。

问答题 简答题
单项选择题

Abortion. The word alone causes civil conversation to flee the room. This is largely because the pro-choice and pro-life positions are being defined by their extremes, by those who scream accusations instead of arguments.

More reasonable voices and concerns, on both sides of the fence, are given little attention.

For example, pro-life extremists seem unwilling to draw distinctions between some abortions and others, such as those resulting from rape with an underage child. They would make no exception in the recent real-life case of a woman who discovered in her fifth month that her baby would be born dead due to severe disabilities.

On the other hand, pro-choice extremists within feminism insist on holding inconsistent positions. The pregnant woman has an unquestionable fight to abort, they claim. Yet if the biological father has no say whatsoever over the woman’s choice, is it reasonable to impose legal obligations upon him for child support Can absolute legal obligation adhere without some sort of corresponding legal rights

The only hope for progress in the abortion dialogue lies in the great excluded middle, in the voices of average people who see something wrong with a young girl forced to bear the baby of a rapist.

Any commentary on abortion should include a statement of the writer’s position. I represent what seems to be a growing "middle ground" in pro-choice opinion. Legally, I believe in the right of every human being to medically control everything under his or her own skin. Many things people have a legal right to do, however, seem clearly wrong to me. adultery, lying to friends, walking past someone who is bleeding on the street. Some forms of abortion fall into that category. Morally speaking, my doubts have become so extreme that I could not undergo the procedure past the first three months and I would attempt to dissuade friends from doing so.

Fanatics on both sides are using reprehensible and deceitful tactics. An honest dialogue on abortion must start by re-setting the stage, by denouncing the approaches that block communication.

The author doubts the legal right to lie to friends as well as the one to ().

A. abort a fetus in its fifth month

B. view the photos of late-term abortion

C. give birth to a baby in one’s teenage

D. dispose of what ever under one’s skin