Pulp and Paper Multiple Choice Questions on “Causticizing Process”.
1. What is a green liquor clarifier?
a) It is a settling tank used to remove dregs by evaporation
b) It is a settling tank used to remove dregs by condensation
c) It is a settling tank used to remove dregs by metamorphism
d) It is a settling tank used to remove dregs by sedimentation
Answer: d
Clarification: It’s a settling tank used to remove dregs by sedimentation before the green liquor is recausticized.
2. What’s a Slaker in Causticizing process?
a) It is a chemical reactor where lime is mixed with black liquor
b) It is a chemical reactor where lime is mixed with brown liquor
c) It is a chemical reactor where lime is mixed with green liquor
d) It is a chemical reactor where lime is mixed with red liquor
Answer: c
Clarification: It’s a chemical reactor where lime’s mixed with green liquor. The reaction temperature is 99-105 degree celcius.
3. Which of the following is a slaking reaction?
a) CaO+H2Oandrarr;Ca(OH)2
b) Na2SO4+4Candrarr;Na2S+4CO
c) 2C+ O2andrarr;2CO
d) CO+1/2 O2andrarr;CO2
Answer: a
Clarification: Slake formation takes place as calcium oxide is made to react with water to produce calcium hydroxide.
4. The lime kiln is a chemical reactor in which lime mud CaO, a process known as calcining.
a) True
b) False
Answer: a
Clarification: The lime kiln is a chemical reactor in which lime mud CaO, a process known as calcining.
5. What is the hidden part?
specific energy consumption=(energy to kiln)/(_________)
a) Ca output
b) CaO output
c) CO2 output
d) CO output
Answer: b
Clarification: The amount of energy required to process the lime is indicated by the specific energy consumption, often reported as Btu/ton.
6. What is the hidden part?
Lime availability= (CaO)/(__________)
a) Caustic
b) Lime
c) Water
d) CO2
Answer: b
Clarification: The purity of the lime is given by the lime available.
7. Salt cake is the make-up chemical for the Kraft process that is used to replace steams lost in pulping.
a) True
b) False
Answer: a
Clarification: Salt cake is the make-up chemical for the Kraft process that is used to replace chemicals lost in pulping.
8. __________ is the collection of waste N.S.S.C liquor and burning it in a nearby Kraft mill.
a) Cross over
b) Cross recovery
c) Bend over
d) Bend recovery
Answer: b
Clarification: Cross recovery is the collection of waste N.S.S.C liquor and burning it in a nearby Kraft mill.
9. ____________ oxides aren’t emitted to a large extent because the CaO is a good scavenger for the highly acidic forms of these compounds and CaSO3 and CaSo4.
a) Sulphur
b) Carbon
c) Calcium
d) Magnesium
Answer: a
Clarification: Supfur oxides aren’t emitted to a large extent because the CaO is a very good scavenger for the highly acidic forms of these compounds and CaSO3
and CaSO4
.
10. __________ formation within the lime kiln is a part of the territory and could be catastrophic?
a) Kink
b) Mask
c) Ring
d) Lumps
Answer: c
Clarification: Ring formation within the lime kiln is part of the territory. If it becomes a severe problem, expensive shutdowns may result.
>