Cement Chemistry cement cement cement cement

cement

1. 1Cement Technology Course
CEMENT TECHNOLOGY COURSE NO 58

2. 2Cement Technology Course
CEMENT TECHNOLOGY COURSE NO 58
CHEMISTRY OF PORTLAND CEMENT CLINKER
0930 -10.15PART 1 Graeme Moir
1015 -10.35INTRODUCTION TO CHEMISTRY
OF CEMENT (RESUME) Andrew Rogers
10.35 -10.50COFFEE
10.50 -11.45PART 2 Graeme Moir
11.45 -12.30SYNDICATE WORK
12.30 -1315LUNCH

3. 3Cement Technology Course
Chemistry of Portland Cement Clinker
•Nature of Portland Cement.
•Clinkering reactions
•Control ratios (LSF, SR,AR)
•Raw mix mineralogy and homogeneity
•Minor constituents
•Determination of chemical and compound
composition
•Special clinkers

4. 4Cement Technology Course
The nature of cement
•Cement manufacture is a basic chemical
process industry.
•It is relatively impure material and the
impurities can have a marked influence on
properties.
•It is seen as a relatively “cheap” commodity.
•Customers have increasingly sophisticated
expectations.
•Consistency of properties is vital.

5. 5Cement Technology CoursePatent for Portland Cement granted to J Aspdin
W Aspdin bottle kiln plant at Northfleet
J Grant introduced tensile strength test for cement
Tube grinding mills for cement.
Rotary kilns introduced.
1820
1840
1860
1880
1900
British (BS 12) and ASTM (C9) Standards published
Method for carbonate of lime developed
LANDMARKS IN PORTLAND CEMENT PRODUCTION

6. 6Cement Technology Course
Precalciner process developed
High efficiency separator introduced for cement grinding
X-ray fluorescence ( XRF) rapid chemical analysis
1920
1940
1960
1980
2000
Automatic kiln control using expert systems (Linkman)
Suspension preheater process introduced
Lepol (nodule) process introduced
Introduction of pneumatic blending silos for raw meal
First electrostatic precipitator installed on cement works
Paper sacks introduced for cement
High pressure roll press for cement pregrinding
New horizontal cement mill technology
LANDMARKS IN PORTLAND CEMENT PRODUCTION (CONT)
Multistage combustion -emission control

7. 7Cement Technology CourseIncrease in Cement 28 day Strength Levels
from 1843 to 2001
Test mortar 1 part cement, 3 parts sand
Stored under water for 28 days.
NOTE :- Compressive strength scale not linear.
1850 1900 1950
1.75
3.5
7
14
28
56
112
Date
Compressive strength Nmm
-2
2000
Figure 2

8. 8Cement Technology CourseOUTLINE OF CEMENT MANUFACTURING PROCESS
STACK


DUST
REMOVAL
RAW
MATERIAL
STORAGE
RAW MIX
GRINDING
BLENDING
&
STORAGE
GYPSUM
CLINKER
STORAGE
CEMENT
GRINDING
MILL
PACKING
PLANT
ROTARY
KILN
BAG &
BULK
CLINKER
COOLER
PREHEATER
FAN
COAL
MILL
Pulverised
coal
Air
COAL
CEMENT
STORAGE
SILOS
Clinker
DUST
RETURN
TO
PROCESS
LIMESTONE
QUARRY
CRUSHING SHALE
QUARRY
Blue Circle
Cement

9. 9Cement Technology Course
Sources Of Cement “Chemicals”
The sources of the basic chemicals required for
cement production are normally described as :
•Primary or calcareous for the main source of
Calcium.
•Secondary or argillaeous for the source of the
other main three.
•Tertiary for purchased chemical “adjusters”.

10. 10Cement Technology Course
Primary Materials
•Limestone
•Chalk
•Marl/Cement rock

11. 11Cement Technology Course
Secondary Materials
•Shales
•Clays
•Sand
•Siltstones

12. 12Cement Technology Course
Tertiary Materials
•Sands
•Iron Ore
•Bauxite
•Industrial by-products e.g. fly ash

13. 13Cement Technology Course
Cement Chemist’s Notation
For simplicity, cement chemists tend to
use a “shorthand” when describing the
chemical formulae of the compounds
present in cement clinker.

14. 14Cement Technology Course
Cement Chemist’s Notation
The four principal elements are
described thus:
C Ca (Calcium)
S Si (Silicon)
A Al (Aluminium)
F Fe (Iron)

15. 15Cement Technology CourseS
AF
C
Chemical Composition of Portland Cement Clinker
Typical Chemical Analysis
Main
Constituents
SiO
Al O
Fe O
CaO
Cement
S
A
F
C
%
21.1
5.6
3.0
65.5
95.2
Chemist's
Shorthand
2
23
23
Minor Constituents
Mn O
P O
TiO
MgO
SO
Loss on
K O
Na O
Fluorine
Chloride
(S)
0.05
0.15
0.30
1.50
1.20
0.50
0.72
0.18
0.04
0.02
4.67
%
ignition
23
25
2
3
-
2
2
Minor
Constituents
Trace elements 0.01

16. 16Cement Technology CourseCOMPOSITION OF THE EARTH'S CRUST
The most abundant elements in the earth's crust and
ElementChemical symbol% by weight
oxygen
silicon
aluminium
iron
calcium
sodium
potassium
O
Si
Al
Fe
Ca
Na
K
49.2
25.7
7.5
4.7
3.4
2.6
2.4
Total 95.5
Expressed as oxides:-
oxide
Chemical
% by weight
silica
alumina
iron oxide
lime
SiO
Al O
Fe O
CaO
55.2
14.2
6.7
4.8
atmosphere are:-
These four oxides typically account for 95% of the
chemical composition of Portland cement clinker.
Cement chemist's
S
A
F
C
symbolshorthand
2
2
2
3
3
FIGURE 4

17. 17Cement Technology CoursePORTLAND CEMENT MANUFACTURE
LIMESTONE
(CHALK)
~ 80 PARTS
+
SHALE
(CLAY)
~ 20 PARTS
HEAT TO
PARTIAL
MELTING
CLINKER
~ 95 PARTS
GYPSUM
~ 5 PARTS
GRIND FINELY
PORTLAND CEMENT

18. 18Cement Technology CourseTYPICAL CHEMICAL ANALYSES OF MATERIALS
LIMESTONE
(95% CaCO )
3
SHALE
MILL
RAW
FEED
KILN
CO GAS
CLINKER
COAL
15% ASH
S
A
F
C
51.7
26.4
9.5
1.6
S
A
F
C
20.9
5.6
3.0
65.7
S
A
F
C
13.2
3.4
1.9
43.0
S
A
F
C
3.3
0.7
0.2
53.5
S
A
F
C
52.8
14.2
8.7
1.0
c 80 PARTSc 20 PARTS
2
% %
%
%
%
Cement Chemist's abbreviations
S - SiOF - Fe O
A - Al OC - CaO
2 2
32
3

19. 19Cement Technology CourseINFLUENCE OF COAL ASH LEVEL ON PROPORTIONS
OF LIMESTONE AND SHALE IN RAW MIX
C 53.5C 1.0C 1.6
LIMESTONE
S 3.3
A 0.7
F 0.2
SHALE
S 52.8
A 14.2
F 8.7
COAL ASH
S 51.7
A 26.4
F 9.5
% % %
CLINKER
COAL ASH PARTICLES
THE COAL ASH MUST BE HOMOGENEOUSLY INCORPORATED INTO THE CLINKER
051015202530
78
79
80
81
82
83
84
22
21
20
19
18
17
% ASH IN COAL
% LIMESTONE % SHALE
16
DRY PROCESS
WET PROCESS

20. 20Cement Technology Course
Principal Compounds
The four major components of cement
clinker are:
C
3S orTri-Calcium Silicate orAlite
C
2S orDi-Calcium Silicate orBelite
C
3A orTri-Calcium Aluminate
C
4AF orTetra-Calcium Alumino-Ferrite

21. 21Cement Technology CourseAlO O OAl
Ca O Ca O
Ca O
CaAlO
326
or
3CaO. Al O
23
or
C A
3
O O OFe
O O
O O
O O
CaAlFeO
4 2 210
or
4CaO.Al O .Fe O
23 23
or
C AF
4
PROPORTIONS OF CALCIUM, ALUMINIUM, IRON
AND OXYGEN ATOMS IN C3A AND C4AF
Note. the arrangement of the atoms shown does not attempt
to illustrate the actual crystalline structure.
C A
3
C AF
4
One formula unit consists of :
3 atoms of calcium (Ca)
2 atom of aluminium (Al)
6 atoms of oxygen (O)
One formula unit consists of :One formula unit consists of :
4 atoms of calcium (Ca)
2 atoms of aluminium (Al)
2 atoms of iron (Fe)
10 atoms of oxygen (O)
FIGURE 7
O
O O
O
O
CaSiO
3 5
or
3CaO.SiO
2
or
CS
3
O
O
SiO O
CaSiO
2 4
or
2CaO.SiO
2
or
CS
2
PROPORTIONS OF CALCIUM, SILICON AND
OXYGEN ATOMS IN C3S AND C2S
Note. the arrangement of the atoms shown does not attempt
to illustrate the actual crystalline structure.
One formula unit consists of :
3 atoms of calcium (Ca)
1 atom of silicon (Si)
5 atoms of oxygen (O)
C S
C S
3
2
One formula unit consists of :
2 atoms of calcium (Ca)
1 atom of silicon (Si)
4 atoms of oxygen (O)
FIGURE 8
Ca
Ca Ca
Ca Ca
OAl Al
Al Al
Fe
Ca
Ca
Ca
Ca
Si

22. 22Cement Technology CourseSCHEMATIC ILLUSTRATION OF CLINKER MINERALS AS OXIDES
C S
C S
3
2
C
S
S
FIGURE 10
CC
C
C
C
C A
3
C AF
4
A
CC
C
AF
CC
CC

23. 23Cement Technology CourseFIGURE 9
CURRENT LEVELS OF THE PRINCIPAL CLINKER MINERALS
SHORTHAND
NOMENCLATURE
C S
C S
C A
C AF
CHEMICAL
FORMULA
3CaO.SiO
or Ca SiO
2CaO.SiO
or Ca SiO
3CaO.Al O
or Ca Al O
4CaO.Al O .Fe O
or Ca Al Fe O
MINERAL
NAME
Alite
Belite
Aluminate
Ferrite
TYPICAL LEVEL
IN BLUE CIRCLE
58
18
10
9
RANGE FOUND
50 - 60
14 - 24
7 - 12
7 - 10
3
2
35
2
2
24
3
23
326
4
2323
42210
CEMENT CLINKERS
IN BLUE CIRCLE
CEMENT CLINKERS
% %

24. 24Cement Technology Course114
13
42
4816
125918
All the calcium is accounted for.
The proportions of the clinker minerals are:-
C4AF 1 part
C3A 1 part
C2S 2 parts
C3S 16 parts
In weight % this corresponds to:-
C4AF 10%
C3A 6%
C4AF
C3A
C2S
C3S
FACS
C2S 8%
C3S 76% CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCC
SSSSSSSSSS
SSSSSSSS
AAF
LSF 98
SR 3.0
AR 1.3
A. UNSATURATED MIX
ILLUSTRATION OF OXIDE PROPORTIONS IN A
TYPICAL RAW MIX

25. 25Cement Technology Course114
13
5418
26118
The additional lime reacts with the C2S and converts it to C3S
The proportions of the clinker minerals are:-
C4AF 1 part
C3A 1 partC3S 18 parts
In weight % this corresponds to:-
C4AF 10%
C3A 6%
C4AF
C3A
C2S
C3S
FACS
C2S nil
C3S 84%
1
ILLUSTRATION OF OXIDE PROPORTIONS IN A
TYPICAL RAW MIXCCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCC
SSSSSSSSSS
SSSSSSSS
AAF
LSF 101
SR 3.0
AR 1.3
B. SATURATED MIX - 2 UNITS OF
LIME (C) ADDED
CC

26. 26Cement Technology CourseCCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCC
SSSSSSSSSS
SSSSSSSS
AAF
LSF 104
SR 3.0
AR 1.3
C. OVER-SATURATED MIX - 2
FURTHER UNITS OF LIME (C)
ADDED
CCCC 114
13
5418
126318
The proportions of the clinker minerals are:-
C4AF 1 part
C3A 1 partC3S 18 parts
In weight % this corresponds to:-
C4AF 10%
C3A 6%
C4AF
C3A
C2S
C3S
FACS
C2S nil
C3S 82%
C (Free lime)2
Free lime 2%
There is no silica available to react with the additional lime
and this remains uncombined in the form of free lime.
ILLUSTRATION OF OXIDE PROPORTIONS IN A
TYPICAL RAW MIX

27. 27Cement Technology CourseCCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCCC
CCCCCCCCC
SSSSSSSSSS
SSSSSSSS
AAF CCCCCCCCC
C
C
C
C
C
C
C
C
C
C
CC
C
C
C
C
C
C
C
C
CC
C
C
C
C
C
CCC
C
C
C
C
CC
C
C
C
C
CC
C
CC
C
C
CC
S
S
Mix must be homogeneous
S
S
SS
SS
C
S
SS
SSS
SSS
S
A
A
F THE RAW MIX MUST BE THOROUGHLY BLENDED

28. 28Cement Technology Course
THE CLINKERING
REACTIONS

29. 29Cement Technology Courselimestone
CaCo3
silica
SiO2
shale/clay
(Al2O3 and SiO2)
iron oxide
Fe2O3
SCHEMATIC ILLUSTRATION OF RAW MIX
PRIOR TO HEAT TREATMENT
50 MICRONS (0.05 mm)
Note, for clarity this schematic illustration only shows
relatively large particles. In an actual raw mix a much higher
proportion of finer particles would be present.

30. 30Cement Technology CourseFIGURE 16
SEQUENCE OF FORMATION OF CALCIUM SILICATES IN A ROTARY KILN
MATERIAL TEMPERATURE
600
800
1000
1200
1400
1600
T C
0
C S
C S
FREE LIME
QUARTZ
CaCO
3
3
2
CALCINING ZONE BURNING ZONE
MOLTEN FLUX
APPEARS
CRYSTALLISATION OF FLUX
TO YIELD C A & C AF
3 4
MOVEMENT OF MATERIAL
RELATIVE
WEIGHT
COOLING ZONE

31. 31Cement Technology CourseSCHEMATIC ILLUSTRATION OF REACTIONS
FOLLOWING HEAT TREATMENT TO 1000 DEG C
Reaction at point of contact
between CaO and silica
to form C2S
Reaction between shale and
CaO to form C12A7 and C2S
Reaction between CaO and
iron oxide to form C2F
(ferrite)
50 MICRONS (0.05 mm)
Decarbonated limestone (CaO)
note cracks/porosity introduced
as a result of ~ 50% loss in mass
and other intermediate compounds
which are not found in the final clinker.

32. 32Cement Technology CourseLiquid phase
molten C3A and C4AF
(Molten mixture of shale,
iron oxide and lime)
lime
unreacted silicaC2Spore
SCHEMATIC ILLUSTRATION OF REACTION
BETWEEN LIMESTONE (LIME) PARTICLE AND
SAND (SILICA) PARTICLE AT 1300 DEG C
5 MICRONS (0.005 mm)
C3S
silica
dissolves
crystallises
from flux
lime
dissolves in
flux and moves
to silica

33. 33Cement Technology CourseC3S
Unreacted C2S
Molten C3A and C4AF
Residual free lime
pore space
SCHEMATIC ILLUSTRATION OF REACTION
BETWEEN LIMESTONE (LIME) PARTICLE AND
SAND (SILICA) PARTICLE AT 1400 DEG C
5 MICRONS (0.005 mm)
pore

34. 34Cement Technology CourseTYPICAL COMBINABILITY CURVES
012345
1,350
1,400
1,450
1,500
1,550
FREE LIME %
TEMPERATURE DEG C
Difficult combinability
Easy combinability
temperature
temperature
Combinability
Combinability

35. 35Cement Technology CourseINFLUENCE OF RAW MIX FINENESS
012345
1,350
1,400
1,450
1,500
1,550
FREE LIME %
TEMPERATURE DEG C
5% PLUS 90 MICRONS
15% PLUS 90 MICRONS
25% PLUS 90 MICRONS
temperature
Combinability

36. 36Cement Technology CourseSCHEMATIC ILLUSTRATION OF CLINKER AT 1400 DEG C
50 MICRONS (0.05 mm)
C3S Free lime cluster
C2S cluster
Clinker flux
(molten C3A and C4AF)

37. 37Cement Technology CourseSCHEMATIC ILLUSTRATION OF CLINKER FIRED TO 1400 DEG C
AND COOLED TO AMBIANT TEMPERATURE
C3S Free lime cluster C2S cluster
C4AF (Ferrite) C3A (aluminate)
Note, the well formed and relatively large C3A and C4AF crystals
indicate that the clinker has been relatively slowly cooled
50 MICRONS (0.05 mm)

38. 38Cement Technology Course
CLINKER NODULES EMBEDDED IN EPOXY RESIN
CUT, POLISHED AND ETCHED WITH ACID

39. 39Cement Technology Course
GOOD QUALITY CLINKER
SMALL UNIFORMLY SIZED C3S AND C2S

40. 40Cement Technology Course
C2S CLUSTER CAUSED BY COARSE SILICA IN
RAW MIX

41. 41Cement Technology Course
NON UNIFORM COAL ASH DISTRIBUTION

42. 42Cement Technology Course
NON UNIFORM COAL ASH DISTRIBUTION
LEADING TO C2S CLUSTERS

43. 43Cement Technology Course
SLOWLY COOLED CLINKER
C3A C4AF
C2S forming
from C3S

44. 44Cement Technology Course
RAPIDLY COOLED CLINKER

45. 45Cement Technology Course
For optimum clinker quality:-
•The kiln feed chemistry must be of low
variability
•The raw meal must be adequately ground
•The coal ash must be uniformly
incorporated into the clinker
•The clinker must be rapidly cooled from
the burning zone temperature

46. 46Cement Technology Course
THE CONTROL RATIOS

47. 48Cement Technology Course
Control Ratios
The three principal ratios used in the
cement industry are:
LSF or Lime Saturation factor
SR or Silica Ratio
AR or Alumina Ratio

48. 49Cement Technology Course
Lime Saturation Factor
Lime Saturation Factor is a
means of describing the capacity
of the other three major elements
to totally use up the lime
(Calcium).

49. 50Cement Technology Course
Calculation of LSF
S x 2.8+A x 1.2+F x 0.65
C x 100
LSF =

50. 51Cement Technology CoursePROPORTIONS OF CLINKER MINERALS
80859095100105
0
10
20
30
40
50
60
70
Wt.%
C3S
C3A
C4AF
C2S
SR 2.5
AR 2.5
LSF %

51. 52Cement Technology CourseBURNING TEMPERATURE REQUIRED TO
REDUCE CLINKER FREE LIME BELOW 2%
9092949698100
1300
1350
1400
1450
1500
1550
LSF %
T°C
15% PLUS
90 MICRONS
10% PLUS
90 MICRONS

52. 53Cement Technology Course
Silica Ratio
Silica Ratio is a method of describing
the amount of Silica that is present in
the mix with respect to the amounts of
Alumina and Iron

53. 54Cement Technology Course
Alumina Ratio
This ratio defines the
proportion of Alumina to Iron.

54. 55Cement Technology Course
Calculations of SR and AR
S
A+F
SR =
AR =
A
F

55. 56Cement Technology CoursePROPORTIONS OF CLINKER MINERALS
11.522.533.54
0
10
20
30
40
50
60
70
SR
Wt.%
C3S
C3A
C4AF
C2S
LSF 100
AR 2.5

56. 57Cement Technology CourseBURNING TEMPERATURE REQUIRED TO
REDUCE CLINKER FREE LIME BELOW 2%
22.533.54
1300
1350
1400
1450
1500
1550
SR
T°C
LSF 98
LSF 95

57. 58Cement Technology CoursePROPORTIONS OF CLINKER MINERALS
0.511.522.53
0
10
20
30
40
50
60
70
Wt.%
C3S
C3A
C4AF
C2S AR

58. 59Cement Technology CourseBURNING TEMPERATURE REQUIRED TO
REDUCE CLINKER FREE LIME BELOW 2%
0.511.522.53
1350
1400
1450
1500
1550
AR
T°C
SR 3.0
SR 2.5
SR 2.0

59. 60Cement Technology CourseSENSITIVITY OF CLINKER PARAMETERS AND
MINERAL PROPORTIONS TO CHANGES IN CHEMISTRY
S
A
F
C
LSF
SR
AR
TARGET
MIX
20.9
5.6
3.0
65.7
97.8
2.43
1.87
( -0.2)
(+0.2)
MINOR
VARIATION
20.7
5.5
3.0
65.9
98.9
2.41
1.87
( -0.5)
(+0.5)
MAJOR
VARIATION
20.4
5.6
3.0
66.2
100.6
2.37
1.87
C S
C S
C A
C AF
67
9
10
9
69
7
10
9
73
3
10
9
Potential phase composition
3
2
3
4
FIGURE 26

60. 61Cement Technology Course
Strengths of clinker minerals
0
15
30
45
60
75
0.1 1 10 100 1000
Days
Strength mPa
C3S C2S C3A C4AF Clinker

61. 62Cement Technology CourseBCC WORKS 1976
949698100
1.5
2
2.5
3
3.5
4
LSF
SR
ABERTHAW
MAGHERMORNE
SUNDON
MASONS
NORMAN
NORTHFLEET
SWANSCOMBE
SHOREHAM
HOPE
HOLBOROUGH
PLYMSTOCK
WEARDALE
OXFORD
CAULDON
WESTBURY
COOKSTOWN
DUNBAR
HUMBER
KIRTON
WORKS STILL
IN PRODUCTION
WORKS NOW
CLOSED
LINDSEY
FIGURE 27

62. 63Cement Technology CourseBCC WORKS 1997
94 96 98 100
1.5
2
2.5
3
3.5
4
LSF
SR
ABERTHAW
MASONS
PLYMSTOCK
CAULDON
NORTHFLEET
HOPE
COOKSTOWN
DUNBAR
WEARDALE
WESTBURY
FIGURE 27

63. 64Cement Technology Course
BCC WORKS 2000
94 96 98 100
1.5
2
2.5
3
3.5
4
LSF
SR
ABERTHAW
CAULDON
NORTHFLEET
HOPE
COOKSTOWN
DUNBAR
WEARDALE
WESTBURY
FIGURE 27

64. 65Cement Technology Course
•Requirement of national customers
(RMC Ltd, Tarmac, Pioneer etc.) for
cement to have the same properties
throughout the UK
•Optimisation of kiln operation
(particularly dry process/precalciner
kilns)
WHY HAS LSF AND SR
RANGE NARROWED?

65. 66Cement Technology CourseCLINKER OXIDE RATIOS AND COMPOUND COMPOSITION OF UK AND US WORKS
DATA FOR JANUARY TO DECEMBER 1997
94 96 98 100
1.5
2
2.5
3
3.5
4
LSF
SR
92
CLINKER LSF AND SR
40 45 50 55 60 65 70
6
8
10
12
14
C3S
C3A
ABERTHAW
CAULDON
COOKSTOWN
DUNBAR
HOPE
MASONS
NORTHFLEET
PLYMSTOCK
WEARDALE
WESTBURY
ATLANTA
HARLEYVILLE
TULSA
ROBERTA
RAVENA
CLINKER C3S AND C3A
ATLANTA
HARLEYVILLE
TULSA
ROBERTA
RAVENA
ABERTHAW
MASONS
PLYMSTOCK
CAULDON
NORTHFLEET
HOPE
COOKSTOWN
DUNBAR
WEARDALE
WESTBURY
BOWMANVILLE
ST MARYS
BOWMANVILLE
ST MARYS
FIGURE 28

66. 67Cement Technology Course949698100
1.5
2
2.5
3
3.5
4
LSF
SR
92
CLINKER LSF AND SR PLANTS OUTSIDE UK AND US
DATA FOR 2000
EWEKORO
SAGAMUASHAKA
RAWANG
KANTHAN
LANGKAWIMILAKI
VOLOS
HALKIS
FORTUNE
REPUBLIC
ILIGAN
ALEXANDRIA
UK PLANTS
US PLANTS

67. 68Cement Technology CourseLIMESTONE
S 3.1
A 0.7
F 0.2
C 53.7
LSF 549
SR 3.15
AR 2.54
MIX 1
S 13.2
A 5.4
F 1.9
C 42.9
LSF 96
SR 1.80
AR 2.85
SHALE
S 50.6
A 22.9
F 7.9
C 2.8
LSF 1.6
SR 1.64
AR 2.88
S 14.1
A 4.1
F 1.5
C 43.7
LSF 96
SR 2.50
AR 2.72
LIMESTONE
S 3.1
A 0.7
F 0.2
C 53.7
LSF 549
SR 3.15
AR 2.54
MIX 2
S 15.9
A 1.6
F 0.8
C 45.2
LSF 96
SR 6.12
AR 2.20
SAND
S 82.4
A 7.4
F 3.6
C 1.0
LSF 0.4
SR 7.53
AR 2.06
ILLUSTRATION OF RAW MATERIAL PROPORTIONING CALCULATIONS
79%21% 84%16%
65%35%
Final mix proportion Limestone : Shale : Sand
80.6013.755.65
Figure 29

68. 69Cement Technology Course
RAW MIX MINERALOGY AND HOMOGENEITY

69. 70Cement Technology CourseFIGURE 30
1.522.533.544.5
1350
1400
1450
1500
1550
SR
COMBINABILITY TEMPERATURE C
1.522.533.544.5
1350
1400
1450
1500
1550
SR
(b)(a)
VARIATION OF COMBINABILITY TEMPERATURE OF WORKS MATERIALS WITH SILICA RATIO
LSF 96%, residue on 90 micron sieve 8%.
AR ratios between 1.1 and 2.8 AR ratios between 1.8 and 2.2
0

70. 71Cement Technology CourseLIMESTONE
S 3.3
A 0.7
F 0.2
C 53.5
SHALE
S 52.8
A 14.2
F 8.7
C 1.0
COAL ASH
S 51.7
A 26.4
F 9.5
C 1.6
% % %
051015202530
% ASH IN COAL
115
105
110
100
95
120
KILN
FEED
LSF
WET PROCESS
DRY PROCESS
INFLUENCE OF COAL ASH LEVEL ON KILN FEED
LSF REQUIRED FOR CLINKER LSF OF 97%
CLINKER
COAL ASH PARTICLES
THE COAL ASH MUST BE HOMOGENEOUSLY INCORPORATED INTO THE CLINKER
FIGURE 31

71. 72Cement Technology CourseLSF 110
Coal ash
deposited on
surface of nodule
LSF 50%
LSF 70%
LSF 90%
NEED TO BURN HARD
TO TRANSPORT LIME AND
SILICA AND REDUCE FREE
LIME TO ACCEPTABLE LEVEL
ILLUSTRATION OF COAL ASH HETEROGENEITY
FIGURE 32
KILN FEED

72. 73Cement Technology CourseLSF 80%
FREE LIME 0.2%
LSF 90%
FREE LIME 0.5%
LSF 100%
FREE LIME 1%
LSF 110%
FREE LIME 6%
Average free lime of nodule = 1.1%
Although free lime level of bulk clinker sample is satisfactory
clinker 'quality' is poor and cement strength properties will
be poorer than indicated by overall chemistry.
Many free lime clusters
CLINKER

73. 74Cement Technology Course
MINOR CONSTITUENTS

74. 75Cement Technology CourseINFLUENCE OF MOST COMMONLY ENCOUNTERED
MINOR CONSTITUENTS ON MANUFACTURING PROCESS
Minor
Constituents
Na O
K O
SO
Range of Levels
in UK Clinker
0.07 - 0.22
0.52 - 1.1
0.5 - 1.5
Influence on
Process
Responsible for
build-ups and
blockages in dry
process and
precalciner plants.
Can 'blind' the bed
in Lepol kilns.
An excess of either
alkalis or SO can
cause difficulties
with clinker
combination.
2
2
3
3
%

75. 76Cement Technology CourseINFLUENCE OF MOST COMMONLY ENCOUNTERED
MINOR CONSTITUENTS ON MANUFACTURING PROCES (CONT)
Fluorine
Chloride
MgO
0.01 - 0.20
0.005 - 0.05
0.8 - 2.5
Greatly assists
clinker combination
by virtue of
mineralising action.
Causes build-ups in
in dry process kilns.
Impairs efficiency
of precipitations on
wet plants.
Slight fluxing action.
Trace Metals5- 100 ppmEnvironment.
Loss of refractories.

76. 77Cement Technology CourseLEVELS OF MINOR CONSTITUENTS IN UK CLINKERS
DATA FOR 2000
ABERTHAW
CAULDON
COOKSTOWN
DUNBAR
HOPE
NORTHFLEET
WEARDALE
WESTBURY
0
0.5
1
1.5
2
2.5
3
K2O
Na2O
SO3
MgO
F2

77. 78Cement Technology CourseLEVELS OF MINOR CONSTITUENTS IN NORTH AMERICAN CLINKERS
DATA FOR 2000
ATLANTA
BOWMANVILLE
HARLEYVILLE
RAVENA
ROBERTA
ST MARYS
TULSA
0
1
2
3
4
K2O
Na2O
SO3
MgO

78. 79Cement Technology CourseLEVELS OF MINOR CONSTITUENTS IN OVERSEAS CLINKERS
DATA FOR 2000
EWEKORO
SAGAMU
ASHAKA
ATHI RIVER
ZIMBABWE
HALKIS
VOLOS IIMA
MILAKI IILA
ALEXANDRIA
0
1
2
3
4
K2O
Na2O
SO3
MgO

79. 80Cement Technology CourseLEVELS OF MINOR CONSTITUENTS IN OVERSEAS CLINKERS
DATA FOR 2000
RAWANG
KANTHAN
LANGKAWI
FORTUNE
REPUBLIC
ILIGAN
EL MELON
0
0.5
1
1.5
2
2.5
3
K2O
Na2O
SO3
MgO

80. 81Cement Technology CourseINFLUENCE OF SO3 ON COMBINABILITY
0 1 2 3 4 5 6
0
2
4
6
8
10
SO3 IN EXCESS OF ALKALIS
(NO ADDED Na2O OR K20)
SO3 ADDED AS K2SO4
FIRING TEMPERATURE 1450 DEG C
FIGURE 35
FREE LIME %
RAW MIX SO3 %

81. 82Cement Technology CourseINFLUENCE OF RAW MIX SO3 AND FLUORIDE ON
COMBINABILITY
COMBINABILITY IS TEMPERATURE REQUIRED TO ACHIEVE
A CLINKER FREE LIME OF 2%.
0 1 2 3 4
0
0.1
0.2
0.3
RAW MIX SO3
RAW MIX F2
1550
1470
1450
1460
1440
1460
1440
1370
15001470
1460
1450
1440
1400
1350
Raw mix LSF - 99%
SR 2.57 & AR 2.53
FIGURE 36

82. 83Cement Technology Course
Limits of volatile toxic metals
Element Max clinker basis (PPM)
As (Arsenic) 300
Cd (Cadmium) 10
Co (Cobalt) 100
Cr (Chromium) 70
Cu Copper) 1000
Hg (Mercury) 2.0
Pb (Lead) 350
Sb (Antimony) 300
Se (Selenium) 50
Tl (Thallium) 5.0

83. 84Cement Technology Course
DETERMINATION OF
CHEMICAL COMPOSITION

84. 85Cement Technology CourseX-ray tube
pressed
disc or
glass bead
detector
primary
X-rays
fluorescence
x-rays
data
CrusherGrinding
mill
High
pressure
press
Fusion
furnace
pressed
disc
glass
bead
mix with flux
Sample
of clinker
Sample of
raw meal or cement
crystal
OUTLINE OF X-RAY FLUORESCENCE ANALYSIS
FIGURE 37

85. 86Cement Technology Course
SPECIAL CLINKERS

86. 87Cement Technology CourseTYPICAL COMPOSITION OF ORDINARY, WHITE
AND SULPHATE RESISTING PORTLAND CEMENTS
Ordinary
Portland
Cement
Sulphate
Resisting
Portland
Cement
White
Portland
Cement
20.2
0.6
5.1
2.3
65.2
1.3
2.7
0.11
0.77
1.3
1.5
98.7
2.7
2.2
60
13
10
7
19.9
0.4
3.6
5.1
64.3
2.1
2.2
0.10
0.50
1.3
2.0
99.1
2.3
0.7
62
10
0.9
15.5
0.07
1.9
0.3
69.1
0.55
2.1
0.14
0.02
0.85
2.3
95
11.2
6.3
66
21
5
1
SiO
Insoluble residue
Al O
Fe O
CaO
MgO
SO
Na O
K O
Loss on Ignition
Free Lime
LSF
SR
AR
C S
C S
C A
C AF
Calculated mineral composition
2
2
2
3
3
3
2
2
3
2
3
4
% % %
24.6
FIGURE 38

87. 88Cement Technology Course
•Portland cement consists mainly of
calcium silicates
•The main (primary) raw material is a
source of lime such as limestone or chalk
•Secondary (and tertiary) materials provide
silica, alumina and iron oxide
•The raw mix must be ground to a fineness
which is appropriate for the raw materials
and thoroughly blended -coarse silica
particles must be avoided
SUMMARY

88. 89Cement Technology Course
SUMMARY (cont)
•The fuel must be ground to the required
fineness and absorbed uniformly in the clinker
•Reducing conditions must be avoided
•The clinker should be cooled rapidly from the
burning zone
•Portland cement contains 4 minerals in the
following typical proportions:
C
3S50 -60% C
3A7 -12%
C
2S 14 -24% C4AF 7 -10%

89. 90Cement Technology Course
SUMMARY (cont)
•The raw mix and clinker chemistry is
controlled using the ratios of LSF, SR and AR
•Differences in clinker chemistry between
works have reduced over the years
•C3S is more reactive than C2S and is mainly
responsible for strength development up to 14
days
•The levels of certain minor constituents must
be closely controlled to optimise production
and ensure satisfactory cement properties
•The potential environmental impact of raw
materials must be considered