Distillation

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Distillation

• Start with a partially fermented product
  (containing some EtOH)
• Through a process of heating, vapor production,
  and condensation, solution with higher EtOH is
  produced
• HOW??

2
Ethanol-Water Phase Diagram
3
Magma

• Differentiate magma based on its chemical
  composition ? felsic vs. mafic

4
Melt Composition freezing T

• Liquid magma freezes into crystals ? the
  composition of what freezes first is governed by
  the melts composition
• Analogous to the composition of seawater ice ?
  icebergs are composed of pure water pure water
  freezes first, leaving the concentrated brine
  behind
• In magmas ? More silica lower T more Ca,
  Mghigher T
• Silica polymerization also affected by T and how
  much Si there is!

5

• Discontinous series Structures change, harder
  to re-equilibrate
• Continuous Series ? plag re-equilibrates quicker
  and if not is a continuum in composition rather
  than a change in mineral as T decreases

rock
Mg2
Fe2
cooling
Mg2
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Silicate structures
nesosilicates
phyllosilicates
sorosilicates
inosilicates
cyclosilictaes
tectosilicates
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Melt-crystal equilibrium 1

• When crystal comes out of melt, some ions go in
  easier ? more Ca rich crystals form 1st
• Precipitated crystals react with cooling liquid,
  eventually will re-equilibrate back, totallly
  cooled magma xstals show same composition
• Magma at composition X (30 Ca, 70 Na) cools ?
  first xstal bytownite

X
liquidus
solidus
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Melt-crystal equilibrium 1

• Magma at composition X (30 Ca, 70 Na) cools ?
  first crystal bytownite (73 Ca, 27 Na)
• This shifts the composition of the remaining melt
  such that it is more Na-rich (Y)
• What would be the next crystal to precipitate?
• Finally, the last bit would crystallize from Z

X
Y
Z
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Melt-crystal equilibrium 1b

• Precipitated crystals react with cooling liquid,
  eventually will re-equilibrate back, totally
  cooled magma xstals show same composition
• UNLESS it cools so quickly the xstal becomes
  zoned or the early precipitates are segregated
  and removed from contact with the bulk of the
  melt

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Why arent all feldspars zoned?

• Kinetics, segregation
• IF there is sufficient time, the crystals will
  re-equilibrate with the magma they are in and
  reflect the total Na-Ca content of the magma
• IF not, then different minerals of different
  composition will be present in zoned plagioclase
  or segregated from each other physically

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Melt-crystal equilibrium 2 - miscibility

• 2 component mixing and separation ? chicken soup
  analogy, cools and separates
• Fat and liquid can crystallize separately if
  cooled slowly
• Miscibility Gap no single phase is stable
• SOUP of X composition cooled in fridge Y vs
  freezer Z

100
SOUP
X
Temperature (ºC)
50
Y
0
fats
ice
Miscibility Gap
Z
-20
10
70
30
90
50
Water
Fat
fat in soup
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Melt-crystal equilibrium 2 - miscibility

• 2 component mixing and separation ? chicken soup
  analogy, cools and separates
• Fat and liquid can crystallize separately if
  cooled slowly
• Miscibility Gap no single mineral is stable in
  a composition range for x temperature

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Equilibrium

• Need a description of a minerals equilibrium
  with its surroundings
• For igneous minerals, this equilibrium is with
  the melt (magma) it forms from or is a
  representation of the Temperature and Pressure of
  formation