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Even though mechanical pulps are generally not exposed to beating/refining, several mills are refining mechanical pulps to try to cut mechanical fiber even further. Why do you think they do that? (Hint: Think about the big advantage of mechanical fibers besides cost, what do mechanical fibers IMPROVE). 

Which of the following statements are true 

How is the vacuum in a vacuum washer (drum washer) usually generated?

Why is Mg salt added to the oxygen bleaching system?

Describe a forward cleaner. Be sure to address the following questions.  Where is the pulp inlet? Separation is accomplished based on what principles? Where do rejects and accepts exit?

Why is it that you generally have a washing stage after every bleaching stage? Do you normally send the bleach plant effluent to chemical recovery section? If not why not? Where do you send the bleach plant effluent then?

Sort the following bleaching chemicals in the order of their selectivity 

Displacement bleaching  (also called dynamic bleaching) is a technique that allows for rapid bleaching. Why are the reaction rates so much higher in this process.

Summarize the overall functions of the recovery boiler in a Kraft mill (I am looking for three main functions.)

Why is the air supply for the primary air inlet in a recovery boiler generally “starving” the system (not enough air is provided to completely burn organic material to CO2)?