Hematra-crysta Flashcards
Crystallization may occur as
A. Formation of solid particles in a vapor
B. Formation of solid particles from a liquid melt
C. Formation of solid crystals from a solution
D. All of the above
D
It is a measure of the quantity of solids actually present in solution as compared to the quantity that is in equilibrium with the solution
A. Saturation point
B. Saturation-Equilibrium point
C. Supersaturation
D. Crystallization point
C
Crystallization cannot occur without supersaturation?
A. Always true
B. False
C. Depends on the solution
D. Depends on the feed temperature
A
A step in crystallization wherein it occurs due to the presence of crystals of the crystallizing species.
A. Primary Nucleation
B. Heterogeneous Nucleation
C. Secondary Nucleation
D. Crystal Growth
C
It is the two-phase mixture of mother liquor and crystals of all sizes,
which
occupies the
crystallizer and is withdrawn as product.
A. Nucleate
B. Magma
C. Hydrate
D. Secondary nucleate
B
Type of solubility curve wherein solubility increases
increases at a certain
transition point while the solubility of the hydrate decreases as temperature increases.
А. Туре І
В. Туре ||
С. Туре III
D. Type IV
D
Type I - Solubility increases with temperature and there are no hydrates or water of crystallization.
Type II - Solubility increases with temperature but curve is marked woth extreme flatness
Type III - Solubility increasing fairly rapid with temperature but it is characterized by breaks and indicates different hydrates or water of crystallization.
Type IV - Unusual Curve; Solubility increases at a certain transition point while the solubility of the hydrate decreases as temperature increases.
A continuous crystallizer consists of an open round bottomed-trough, 24-in wide by 10 ft long, and containing a long ribbon mixer that turns at about 7 rpm.
A. Agitated Batch Crystallizer
B. Swenson Walker Crystallizer
C. Salting Evaporator
D. Oslo Crystallizer
B
The following are the methods of generating supersaturation except:
A. Evaporation
B. Cooling
C. Reaction
D. Compression
D
This unit is particularly well adapted to the production of large-sized uniform crystals that are usually rounded.
A. Agitated Batch Crystallizer
B. Swenson Walker Crystallizer
C. Salting Evaporator
D. Oslo Crystallizer
D
It states that if all crystals in magma grow in supersaturation field and at the same temperature and if all crystal grow from birth at a rate governed by the supersaturation, then all crystals are not only invariant but also have the same growth rate that is independent of size.
A. delta L law of crystals
B. delta H law of crystals
C. delta P law of crystals
D. Equilibrium saturation law
A
A type of crystallizer wherein it is used in applications in which excessive nucleation occurs
A. Forced Circulation
B. Oslo
C. Draft Tube Baffle
D. Vacuum
C
Crystallizer that is particularly useful when processing materials that tend to grow on the walls of continuous crystallization equipment
A. Swenson Walker
B. Oslo
C. Draft Tube Baffle
D. Vacuum
D
A method of supersaturation generation wherein it uses vessel walls, internal coils, or by pumping mother liquor through an external heat exchanger. This is used when solubility changes significantly with temperature and when the feed stream is near saturation at high temperature.
A. Cooling
B. Evaporation
C. Reaction
D. Drowning out
A
Another method wherein pressure is reduced to form a boiling zone at the top of the vessel.
A. Cooling
B. Evaporation
C. Reaction
D. Drowning out
B
Miscible solvent is added resulting in a mixture in which product is less soluble.
A. Cooling
B. Evaporation
C. Reaction
D. Drowning out
D
