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VII COLOQUIOS DE DIRECTORES Y TÉCNICOS DE FÁBRICAS DE CEMENTO, Málaga, 17, 18 y 19 de noviembre de 2009

Latest news on the applicationof the Rietveld method toquality control of cements

Ángeles G. De la Torre

[email protected]

University of Málaga, Spain


OutlineRietveld method: History and theoryParameters controlled by XRD & Rietveld

Control-files/turn-keySulphate carriers: gypsum, bassanite or anhydriteAdditions (filler, pozzolans, etc.)Cement storage: syngeniteClinkering process

Conclusions

XRD & Rietveld: more knowledgeAlternative FuelsBlockage of preheatersRaw materials: Gypsum


History1967 Rietveld: neutron diffraction for structure refinementAfter that: X-ray diffractionand also: quantitative phase analysis

Dr. Hugo M. Rietveld

Important goals: Development of fast X-ray detectorsDevelopment of powerful computers


Cement is specified for its properties

The phases (not the elemental composition) determine the mechanical properties

The better control of the clinker phases leads directly to the expected properties

Knowledge of the possible properties leads to a better control in cement blending

Why is XRD important for Clinker and Cement?

Difference curveDifference curve

What does the Rietveld method consist on?Comparison of a calculated and an experimental XRD pattern

X-Rays X-Ray

sX-Rays X-Ray

s


Central laboratories for research supportServicios Centrales de apoyo a la investigación (SCAI)

XRD laboratoryLaboratorio de Difracción de rayos-X

http://www.uma.es/scai/servicios/xrd/xrd.html

XRD specialized analyst Research fellow

Control-files/turn-key

Parameters controlled by XRD & Rietveld

Special situations


It is completely automated

ININ

Software previously adapted by

experts

Rietveld


0

10

20

30

40

50

60

70

80

0 5 10 15 20

Sample

Wt %

C3SC2SC4AFC3ACaOMgOK2SO4K3Na(SO4)2

Work prior to installation of control-file(s):Measure 4-6 samples/control-file @ your diffractometer, (mandatory)Send some grams of additions (filler, pozzolan, slag, …), (optional)



943.9(1)0.7(1)0.9(1)5.2(2)10.9(2)22.5(4)52.2(4)

946.26(3)-1.4(2)5.0(2)11.4(3)12.7(6)62.1(4)

LSFBassanite/%Gypsum/ %aftitalite/ %C3A/ %C4AF / %C2S / %C3S/ %

Sulphate carriers: gypsum, bassanite or anhydrite

Cem1Cem2

3950

4200

Blaine/ cm2g-1

43.5

44.6

R7/ Nm-2

35.8

37.8

R3/ Nm-2

51.1

53.8

R28/ Nm-2

11033.823.1Cem2

8534.128.8Cem1

Setting time/ min

R2/ Nm-2

R1/ Nm-2

XRD & Rietveld

Gypsum

Bassaniteanhydrite

The only way to control and understand setting

Dehydration of gypsum to bassanite/anhydrite on milling process

Or Natural raw material




Additions (filler, pozzolans, etc.)

CEM II B-P

Pozzolan(mixture of amorphous and

crystalline material)

PP

CEM II B-L

Filler (crystalline material)

L

L




Cement storage: syngenite

From: http://www.webmineral.com/

K2Ca(SO4)2·(H2O)

Arcanite + calcium sulphates = syngenite(high humidity)




Clinkering process: From the milling point of view

XRD & Rietveld

Similar LSFHigh amounts of C3S, no free

lime

High mechanical strengths expected at early ages

Clink-2 and Clink-3 OK BUT

Clink-1 develops low mechanical strengths at early ages¡¡¡???



Clinkering process: milling companyXRD & Rietveld Clink-2 and Clink-3 OK

BUTClink-1 develops low mechanical strengths at early ages¡¡¡???

C3S in clink-1 presents high crystallinity and larger

particlesThe split is shown

Thus, C3S is less reactive

Why is more crystalline??Why their particles are bigger?

The clinker was not properly cooled (slowly) and likely overheated.

Only XRD



--1.1 ± 0.1ZnO (zincite)

1.0 ± 0.20.3 ± 0.2*CaMg(CO3)2 (dolomite)

7.3 ± 0.210.8 ± 0.3CaCO3 (calcite)

0.3 ± 0.1*0.8 ± 0.1SiO2 (quartz)

1.1 ± 0.21.3 ± 0.1CaSO4 (anhydrite)

3.8 ± 0.23.8 ± 0.2CaSO4·1/2H2O (bassanite)

6.2 ± 0.35.7 ± 0.3Ca2AlFeO5 (C4AF)

5.8 ± 0.25.3 ± 0.2Ca3Al2O6 (C3A)

9.1 ± 0.58.5 ± 0.5Ca2SiO4 (C2S)

65.5 ± 0.562.4 ± 0.5Ca3SiO5 (C3S)

CEM-2CEM-1Phase

Alternative Fuels%

of a

ltern

ativ

e fu

els

used

in E

urop

e (2

003)

C

3SC

3S

C3S

C3S

C3S

C3S

C4A

FC

3A

calc

ita

ZnO

ZnO

basa

nita

C2S

C3S

C3S

C3S

C3S

C3S

C3S

C4A

FC

3A

calc

ita

ZnO

ZnO

basa

nita

C2S

XRD & Rietveld: more knowledge


Blockage of preheaters

2.1(2)1.6(2)1.9(1)SiO2 (coesite)

1.4(1)1.2(1)1.6(1)MgO

1.5(2)2.7(1)7.5(3)CaCO3

8.5(2)9.0(2)3.4(2)Ca12Al14O33

1.1(1)-7.4(1)CaO

--1.1(2)Ca3Al2O6

6.4(2)5.7(2)9.9(2)Ca4Al2Fe2O10

31.6(4)11.1(3)58.7(4)-Ca2SiO4

2.7(1)1.9(1)-CaS

3.7(2)7.3(3)3.4(2)Ca11(SiO4)4O2S (jasmundite)

--1.1(1)Ca4Al6O12(SO4) (Yeelimite)

2.9(2)0.9(1)1.3(1)CaSO4

21.4(4)36.5(4)2.7(2)Ca5(SiO4)2SO4 (ternesite (sulfo-spurrite))

16.6(5)22.1(4)Ca5(SiO4)2CO3 (spurrite)

321Phases

2.1(2)1.6(2)1.9(1)SiO2 (coesite)

1.4(1)1.2(1)1.6(1)MgO

1.5(2)2.7(1)7.5(3)CaCO3

8.5(2)9.0(2)3.4(2)Ca12Al14O33

1.1(1)-7.4(1)CaO

--1.1(2)Ca3Al2O6

6.4(2)5.7(2)9.9(2)Ca4Al2Fe2O10

31.6(4)11.1(3)58.7(4)-Ca2SiO4

2.7(1)1.9(1)-CaS

3.7(2)7.3(3)3.4(2)Ca11(SiO4)4O2S (jasmundite)

--1.1(1)Ca4Al6O12(SO4) (Yeelimite)

2.9(2)0.9(1)1.3(1)CaSO4

21.4(4)36.5(4)2.7(2)Ca5(SiO4)2SO4 (ternesite (sulfo-spurrite))

16.6(5)22.1(4)Ca5(SiO4)2CO3 (spurrite)

321Phases

C2S

Tern

esite

C2S C

2SC

2S

Spu

rrite

Jasm

undi

te

1

SO3 cycle?Cl-?

A Challenge¡¡



Raw materials: Gypsum

A sample of Gypsum which wasnot suitable for white cements¡¡ Why??

Celestitegives

color to the

gypsum



X-Rays X-Ray

sX-Rays X-Ray

s

XRD & Rietveld for quality control of clinker and cementsFind correlations between mineralogical compositions and performances

XRD & Rietveld @ external specialised laboratories for special situations

Conclusions

Thanks to remaining authors

Miguel A. G. ArandaLaura León-Reina

Héctor Alonso-Llorente

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