[Soda Ash Knowledge] Question of the Day (130) February 10, 2010

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Please hide replies; otherwise, no scoring will be given in principle. Edited posts will not be scored. Specific hiding method: http://bbs.hcbbs.com/viewthread.php?tid=492556&highlight=%D2%FE%B2 %D8 The topic for this issue is taken from the book “Question Bank for Vocational Training of Technical Workers – Operators in Soda Ash Production”; the electronic version of this book can be downloaded at: http://bbs.hcbbs.com/thread-13140-1-2.html

I. Multiple-choice questions:
1. The characteristics of the ammonia absorption process include: ( )
A. High-efficiency cooling equipment and low-temperature cooling water are used for ammonia absorption.
B. Ammonia absorption can take place under negative pressure, which also allows the distillation of ammonia to occur under negative pressure, thereby reducing steam consumption during this process.
C. The ammonia concentration should not be too high, to avoid blockages in the equipment and pipelines.
D. The ammonia absorption process is related to the methods used in brine purification.

2. Water vapor cannot be cooled before entering the ammonia absorption system, in order to prevent crystals from blocking the gas pipelines. This is because: ( )
A. Solid (NH4)2CO3·H2O forms.
B. Solid NH4HCO3 forms.
C. Solid NH4COONH2 forms.

3. The main components of ammonium salt cement include: ( )
A. NaCl
B. Na2CO3
C. CaCO3
D. MgCO3