5.5 Phase diagrams of three-component systems ---ternary phase diagrams ( ) T or ( ) P ( ) T,P.

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5.5 Phase diagrams of three- component systems ---ternary phase diagrams 1, 4 f Φ 1 Φ 3 * f 1 Φ 2 * * f 3, F 32 C Φ ( ) T or ( ) P ( ) T, P

Transcript of 5.5 Phase diagrams of three-component systems ---ternary phase diagrams ( ) T or ( ) P ( ) T,P.

5.5 Phase diagrams of three-component systems ---ternary phase diagrams

1, 4f Φ

1Φ 3* f

1Φ 2** f

3, F 3 2C Φ

( )T or ( )P

( )T,P

The Gibbs Triangle

Equilateral triangle coordinates

1''' cbacba

a'b'c'

O, content point

Content of A in the system

Content of B in the system

Content of A in the system

Mass fraction

22%B, 36%C, 42%A

'

'

''

''

b

c

b

c

5.5.1 Composition characters for equilateral triangle coordinates

d,e,f the mass fractions of A are equal

Points on AD line,

On line AD, D’ is closer to A than D, the mass fraction of A in D’ is more than that in D

OEOD ED mm

The level rule for three-component systems

D+E O O must be on the line DE

Tie line

A BAS bSm m

S b

Sb

The mass fraction of A decrease, mA of A is separated from S (Φ=2, L+A)

mA of A is added into the system

Centre-of-gravity rule of three-components system

D + E + F H

5.5.2 Partly miscible three-components liquid system

a1-a4,

b1-b4,

a1-b1, a2-b2,a3-b3….. conjugate solution

O:isothermal consolute point

aob:binoal curve

B: H2O:Butanol:CH3COOH=30%:30%:40%=A+C

A: 43%:22%:35%

C: 14%:63%:23%

A:C = 23:18

T - x1 , x2

Two phase

Single phase

There are one couple of partly miscible components

Two couples of partly miscible components

Vinyl cyanide(A)

water(B)

ethanol(C)

Two-phase

Single phase

Two-phase

Single phase L1

Single phase L2

There are three couples of partly miscible components

Vinyl cyanide(A)

water(B)

ether(C)

Single phase

Two-phase

** 0f C Φ

Two-phase

Φ=1 Φ=3 D,E, F

Separation of liquid mixtures by extraction

Extraction Column

5.5.3 Ternary water-salts systems

Φ=1 L

Φ=2 B(s), L Φ=2

C(s), L

Φ=3, B(s), C(s), FΦ=3, the saturation solution of B and C

How to get pure B from mixtures of B and C

Q-----R(L+B)

OHKNONaNO 233

T=298KT=373K

Effect of temperature on phase diagram

Purification of salt

X(KNO3+NaNO3)…..D(298K)+KNO3…D(373K)…

X’: W……D‘……y……D

5.5.4 Three-component system containing threebinary eutectic points

T-x

Pb-Sn-Bi trinary system

1 2 3 , , E E E

Φ=1, L

Φ=2, L+Pb

Φ=2, L+Sn

Φ=2, L+Bi

Triple point

Bi/Sn, Sn/Pb, Pb/Bi

Φ=3, L+Bi(S)+Sn(S)

Eutectic T decrease

E4, L+Bi(S)+Sn(S)+Pb(S)

Φ=3, L+Pb(S)+Sn(S)

T decrease:

A(Φ=1,L)…

L+Bi(S)

L+Bi(S)+Sn(S)

L+Bi(S)+Sn(S)+Pb(S)

Φ=4, f=0

The composition variation path

5.6 The surfactant/oil/water trinary system

Homework

Y: P188 39

Review the whole chapter