Saturated aqueous solutions in Potash industry. Modeling of - - PowerPoint PPT Presentation

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Dec 15, 2023 114 likes •431 views

Saturated aqueous solutions in Potash industry. Modeling of properties and composition Sergei Panasiuk, Ph.D. Chief mineral process specialist WorleyParsons Canada, Minerals & Metals Potash any potassium compound (KCl

SLIDE 1

 Saturated aqueous solutions in Potash

industry. Modeling of properties and composition

 Sergei Panasiuk, Ph.D.

Chief mineral process specialist



WorleyParsons Canada, Minerals & Metals

SLIDE 2

 Potash – any potassium compound (KCl – most common).  Potash = “pot ashes” old method of making K2CO3 by

leaching of wood ashes, evaporating the resulting solution in iron pots.

 The first U.S patent issued in 1790 and sighed by G.

Washington. “in the making of Pot ash … by new Apparatus

and Process”.

SLIDE 3

Samuel Hopkins “…making of Pot ash and Pearl ash by a new Apparatus and Process”

In 1791, Government of Lower Canada (Quebec) issued “letter of reward” to Hopkins for his improved method. Regarded as the first “patent” issued in Canada.

SLIDE 4

SLIDE 5

Potassium minerals

Mineral Composition K2O, % Chlorides:

Sylvinite KCl · NaCl mixture 28 Sylvite KCl 63 Carnalite KCl · MgCl2 · H2O 17 Kainite 4KCl · 4MgSO4 · 11H2O 19 Hanksite KCl · 9Na2SO4 · 2Na2CO3 3

Sulphates:

Polyhalite K2SO4 · 2MgSO4 · 2CaSO4 · 2H2O 16 Langeinite K2SO4 · 2MgSO4 23 Leonite K2SO4 · MgSO4 · 4H2O 26 Schoenite K2SO4 · MgSO4 · 6H2O 23 Krugite K2SO4 · MgSO4 · 4CaSO4 · 2H2O 11 Glaserite 3K2SO4 · Na2SO4 43 Syngenite K2SO4 · CaSO4 · H2O 29 Aphthitalite (K,Na)2SO4· 30 Kalinite KAl(SO4)2 · 11H2O 10 Alunite K2Al6(OH)12 · (SO4)4 11

Nitrates:

Niter KNO3 47

Mines (Canada, USA, Russia) - 96% Evaporating ponds (USA, Jordan, Israel) - 3% NEW

SLIDE 6

Potash deposits composition

Dead Sea KCl·NaCl K2SO4·2MgSO4 Seawater

SLIDE 7

KCl-NaCl mining 1000m deep

SLIDE 8

Surface mining Dead Sea

SLIDE 9

Block Flow Diagram – Potash Solution Mine

Solubility:

Flotation (salts and amines)
U/G solution mining
Brine evaporation
KCl crystallization
Brine U/G injection

Density:

U/G solution mining
Evaporation/crystallization
Brine U/G injection

Vapor pressure and composition:

Evaporation/crystallization
Exhaust gas scrubbers
Dryers

Boiling point elevation:

Evaporation/crystallization
Dryers

SLIDE 10

SLIDE 11

KC l- NaCl - MgCl2 - H2O

SLIDE 12

METSIM(PFD KCl centrifuges)

SLIDE 13

METSIM solubility equilibrium

SLIDE 14

METSIM – Equilibrium functions

SLIDE 15

KC l- NaCl - H2O

OLI NaCls KCls NaCl – KCl invariant

SLIDE 16

KC l- NaCl - H2O

5 10 15 20 25 30 35 5 10 15 20 25 30 35 40

NaCl, weight % KCl, weight %

OLI data

0C 25C 50C 75C 100C 150C NaCl KCl NaCl + KCl

SLIDE 17

KC l- NaCl -H2O invariant solubility

NaCl KCl

SLIDE 18

Solution mine

NaCl saturated KCl depleted KCl -NaCl NaCl NaCl 65 °C 55 °C NaCl saturated KCl saturated 1500 m depth

SLIDE 19

Solution mine

NaCl KCl ΔC (KCl)

SLIDE 20

Solution mine with evaporaton

NaCl KCl ΔC (KCl) ΔC (NaCl) ΔCevp (KCl)

SLIDE 21

Saskatchewan solution mine

NaCl KCl ΔC (KCl) ΔC (NaCl) ΔCevp (KCl) ΔCfr (KCl)

SLIDE 22

KC l- NaCl - MgCl2 - H2O

NaCl + KCl 100 g/ L MgCl2 20 g/ L MgCl2 0 g/ L MgCl2

SLIDE 23

KC l- NaCl - CaSO4 - H2O

SLIDE 24

pH of vapor condensate

Vapor: HCl-H2O

SLIDE 25

No problems?

OLI predicts proper pH for the vapor condensate from evaporators but not for dryers.

1

MgCl2·2H2O = MgOHCl + HCl + H2O t > 135 °C

SLIDE 26

Problem 2

NaCl saturated KCl depleted KCl -NaCl NaCl NaCl 65 °C 55 °C NaCl saturated KCl saturated 1500 m depth

SLIDE 27

Oversaturation

Reality - >10% undersaturation for KCl

SLIDE 28

Problem 3. Complexity

SLIDE 29

Process Flow Diagrams (Dryers)

SLIDE 30

Dynamic process simulation

SLIDE 31

Conclusions:

Potash industry requires accurate prediction of solubility in system

K-Na-Mg-Cl-SO4-H2O system

Predictions of the brine density, boiling point elevation, viscosity,

vapor pressure and compositions are also very important

METSIM uses polynomial functions to approximate some of the

brine parameters

OLI is capable to predict all required brine properties in the wide

range of conditions

OLI and METSIM predictions of the brine properties are very

similar in the narrow range of the most common potash industry applications.

Computer simulation of the large industrial projects requires to use

 Saturated aqueous solutions in Potash

 Sergei Panasiuk, Ph.D.

 Potash – any potassium compound (KCl – most common).  Potash = “pot ashes” old method of making K2CO3 by

leaching of wood ashes, evaporating the resulting solution in iron pots.

 The first U.S patent issued in 1790 and sighed by G.

and Process”.

Samuel Hopkins “…making of Pot ash and Pearl ash by a new Apparatus and Process”

In 1791, Government of Lower Canada (Quebec) issued “letter of reward” to Hopkins for his improved method. Regarded as the first “patent” issued in Canada.

Potassium minerals

Potash deposits composition

KCl-NaCl mining 1000m deep

Surface mining Dead Sea

Block Flow Diagram – Potash Solution Mine

KC l- NaCl - MgCl2 - H2O

METSIM(PFD KCl centrifuges)

METSIM solubility equilibrium

METSIM – Equilibrium functions

KC l- NaCl - H2O

KC l- NaCl - H2O

KC l- NaCl -H2O invariant solubility

Solution mine

Solution mine

Solution mine with evaporaton

Saskatchewan solution mine

KC l- NaCl - MgCl2 - H2O

KC l- NaCl - CaSO4 - H2O

pH of vapor condensate

No problems?

1

Problem 2

Oversaturation

Problem 3. Complexity

Process Flow Diagrams (Dryers)

Dynamic process simulation

Conclusions:

K-Na-Mg-Cl-SO4-H2O system

vapor pressure and compositions are also very important

brine parameters

range of conditions

similar in the narrow range of the most common potash industry applications.

some simplifications of OLI approach