SOLUTIONS IN FTPulp

 

[FILE]

[FTPulp-Melt]

Base:                  FTPulp

Phase:                Salt liquid

Full Name:          MeltA, MeltB, MeltC or Melt?

 

 

 

Components:                                       

FTPulp-MeltA: NaCl, Na2CO3, Na2SO4, NaOH, Na2S, KCl, K2CO3, K2SO4, KOH, K2S

 

FTPulp-MeltB:  NaCl, Na2CO3, Na2SO4, Na2S2O7, Na2S3O10, Na2O, Na2O2, NaOH, KCl, K2CO3, K2SO4, K2S2O7, K2S3O10, K2O, K2O2, KOH

 

FTPulp-MeltC: Na2S, Na2S2, Na2S3, Na2S4, Na2S5, Na2S6, Na2S7, Na2S8, Na, K2S, K2S2, K2S3, K2S4, K2S5, K2S6, K2S7, K2S8, K

 

FTPulp-Melt?:  NaCl, Na2CO3, Na2SO4, Na2S2O7, Na2S3O10, Na2O, Na2O2, NaOH, Na2S, Na2S2, Na2S3, Na2S4, Na2S5, Na2S6, Na2S7, Na2S8, Na, KCl, K2CO3, K2SO4, K2S2O7, K2S3O10, K2O, K2O2, KOH, K2S, K2S2, K2S3, K2S4, K2S5, K2S6, K2S7, K2S8, K

Selection Type: I (possible 2-phase immiscibility)

 

 

FTPulp-MeltA corresponds to the liquid phase of the major salts found in the recovery boiler. The subsystem NaCl-Na2CO3-Na2SO4-KCl-K2CO3-K2SO4 in  FTPulp-MeltA is identical to that in FTsalt-SALT.

 

FTPulp-MeltB contains acidic sulfates, such as Na2S2O7 and K2S2O7 in the liquid phase but no reduced sulphur species (such as Na2S and Na2S2) for corrosion related processes.

 

FTPulp-MeltC contains polysulfide species, Na2Sn and K2Sn (n>1) in the liquid phase and metallic alkali, but no oxygen-containing species.

 

 FTPulp-Melt? contains all above-mentioned species in the liquid phase but an optimization of the whole system has not been made.

 

 

The Modified Quasichemical Model in the Quadruplet Approximation has been used for this solution.  The model assumes a non-random mixing of elemental cations and anions on their respective sublattices.  1st and 2nd nearest-neighbour short-range ordering is calculated by the model by modifying the configurational entropy as a function of 1st and 2nd nearest-neighbour pair energies.

 

Cations:  Na+, K+

 

Anions: Cl-, CO32-, SO42-, S2O72-, S3O102- S2-, S22-, S32-, S42-, S52-, S62- S62-, S82-, O2-, O22- and Va-(charged vacancy)

 

 

SOLID SOLUTIONS IN FTPULP

 

[FTPulp-Hexa]      Na,K//SO4,CO3,S(ss)

A SOLID ALKALI SULFATE/CARBONATE/SULFIDE SOLUTION

 

 

Na,K//SO4,CO3,S dilute in both Na2S and K2S (the mole fractions of Na2S and K2S are both < 0.5).

 

High-temperature, hexagonal Na2SO4-K2SO4- Na2CO3-K2CO3-Na2S-K2S solid solution.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-ORTA]      K,Na//CO3,SO4(ss)

A SOLID ALKALI CARBONATE/SULFATE SOLUTION

 

Na2SO4 with Na2CO3, K2SO4 and K2CO3 in solution

Orthorhombic low temperature modification.

 

Calculated composition must be rich in Na2SO4 to be valid.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-ORTB]      K,Na//CO3,SO4(ss)

A SOLID ALKALI CARBONATE/SULFATE SOLUTION

 

K2SO4 with Na2CO3, Na2SO4 and K2CO3 in solution

Orthorhombic low temperature modification.

 

Calculated composition must be rich in K2SO4 to be valid.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-KCO]      K,Na//CO3,SO4(ss)

A SOLID ALKALI CARBONATE/SULFATE SOLUTION

 

K2CO3 with Na2CO3, K2SO4 and Na2SO4 in solution (mole fraction of K2CO3 > 0.4).

 

Low temperature modification.

Calculated composition must be rich in K2CO3 to be valid.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-NKCB]      K,Na//CO3,SO4(ss)

A SOLID ALKALI CARBONATE/SULFATE SOLUTION

 

Na2CO3 with K2CO3, K2SO4 and Na2SO4 in solution (mole fraction of K2CO3 > 0.4).

 

Low temperature modification.

Calculated composition must be rich in Na2CO3 to be valid.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-NKCA]      K,Na//CO3,SO4(ss)

A SOLID ALKALI CARBONATE/SULFATE SOLUTION

 

Na2CO3 with K2CO3, K2SO4 and Na2SO4 in solution (mole fraction of K2CO3 > 0.4).

 

Very-low temperature modification.

Calculated composition must be rich in Na2CO3 to be valid.

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-Gsrt]      K3Na(SO4)2

SOLID NON-STOICHIOMETRIC K3Na(1+x)(SO4)2

 

Dilute solid solution of (Na2SO4)2 in K3Na(SO4)2.

 

 

 

[FTPulp-NPYR]      (Na,K)2S2O7(ss)

A SOLID ALKALI PYROSULFATE

 

Na2S2O7 with K2S2O7 in solution

Calculated composition must be rich in Na2S2O7 to be valid.

 

 

[FTPulp-LPYR]      (K,Na)2S2O7(ss)

A SOLID ALKALI PYROSULFATE

 

K2S2O7 with Na2S2O7 in solution

Calculated composition must be rich in K2S2O7 to be valid.

 

 

 

[FTPulp-ALKA]      BCC Na-K

A Na-K BCC SOLID SOLUTION

 

Solid solution of BCC Na-K

Possible miscibility gaps. Use I option.

 

 

 

[FTPulp-NAKS]      (K,Na)2S(ss)

A SOLID ALKALI SULFIDE SOLUTION

 

Solid solution of Na2S-K2S

Possible miscibility gaps. Use I option.

 

 

 

[FTPulp-KNS2]      (K,Na)2S2(ss)

A SOLID ALKALI DISULFIDE SOLUTION

 

Solid solution of Na2S2-K2S2

Possible miscibility gaps. Use I option.

 

 

 

[FTPulp-ACl]      K,Na//Cl,OH(ss)

A SOLID ALKALI CHLORIDE SOLUTION

 

Solid solution of NaCl-KCl partially dissolving NaOH-KOH

Possible miscibility gaps. Use J option.

 

 

 

[FTPulp-AOH]      (K,Na)OH(ss)

A SOLID ALKALI HYDROXIDE SOLUTION

 

Solid solution of NaOH-KOH

Possible miscibility gaps. Use I option.