3. PE Pyroprocessing II Training
3
FIRST RULE
Reducing raw mix rejects lowers burning temperature
and grinding energy. This is particularly the case with
siliceous rejects.
This action is also beneficial to strength properties.
Key Figures:
When the amount of 100 µm rejects is reduced from 20 to 10%
the global raw mix cement energy consumption is lowered by
about 4 kWh per ton of cement at a fineness of 350 m²/kg.
Fuel saving for burning
&
Decrease cement specific griding energy
4. PE Pyroprocessing II Training
4
Finer raw mix = Saving kW
at finish grinding
Raw mix CPA HPR
Month
>100µm >200µm Blaine t/h mill R1
February 20.0 2.0 3850 49.0 22.5 35.7 70.0
March 13.0 0.8 3850 52.5 24.0 37.0 71.0
April - May 13.0 0.8 3680 55.5 22.6 37.0 70.0
R2 R28
Contes
5. PE Pyroprocessing II Training
5
SECOND RULE
Short burning zone promote grindability and strength
development.
Key Figures:
The optimum is achieved when the kiln couple is at minimum
compatible with steady operations.
Decrease cement specific griding energy
6. PE Pyroprocessing II Training
6
Shorter burning zone: better grindability
Grindability and burning zone length
Le Teil
30/05/1995 04:00 30/05/1995 12:00 30/05/1995 20:00 31/05/1995 04:00 31/05/1995 12:00
200
250
300
350
400
450
500
Kiln
Amps
50
55
60
65
70
75
80
Kiln amps decrease
Grindability increase
7. PE Pyroprocessing II Training
7
THIRD RULE
Steady production requires an oxidizing atmosphere
because a reducing atmosphere increases
volatilization, causing both "cyclical" operations and
sulfate and alkali fluctuations, hence producing an
irregular clinker.
Stable kiln operation decrease builds-up
Uform cement quality
9. PE Pyroprocessing II Training
9
FOURTH RULE
Increasing the clinker free lime content reduces both
initial and final setting times in the same proportion.
Adding lime also accelerates both initial and final
setting times.
Key Figures:
When free CaO increases from 0.5 to 1.5%, initial set
decreases by about 40 to 50 minutes. This impact may vary
greatly from clinker to clinker (-10 to -100 minutes).
Lime quality (specifically the burning temperature, its
hydration level, etc.) and clinker quality have an influence on
the results obtained.
Customer satisfaction
10. PE Pyroprocessing II Training
10
100
120
140
160
180
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Chaux libre clinker
Initial setting time (mortar)
( min. )
%
Free lime and setting time reduction
St Constant
11. PE Pyroprocessing II Training
11
Normal + 5 % Limestone
Ash 1 2
Free lime 1,10 2,10 2,90 2,50
Blaine 4320 4480 4600 4420
Setting time 175 110 110 135
(mn) 245 180 170 255
Strength EN 24,7 25,3 24,5 24,0
(MPa) 69,1 67,2 66,9 67,2
Steam cured 0,5 3,8 6,0 3,8
80°C (MPa)
%
cm2 /g
initial
final
1d
28d
2h30
5h30 24,1 29,4 25,3 26,7
Limestone injection at the cooler
Val d'Azergues
12. PE Pyroprocessing II Training
12
FIFTH RULE
Increasing clinker C3S (to the detriment of C2S)
improves strength at 1, 2, 3 and 7 days. After 28 days,
the gain may be less because of the C2S contribution.
Key Figures:
+10% C3S +2 to 5 MPa for early strength
Customer satisfaction
13. PE Pyroprocessing II Training
13
Strength = f (C3S)
50.0 55.0 60.0
C3 S
40.0
N/mm
2
15.0
20.0
25.0
45.0
30.0
35.0
45.0
50.0
55.0
60.0
y = 0.4495x - 2.5851
r2 = 0.4284
R-1d
y = 0.5471x + 15.509
r2 = 0.5785
R-7d
y = 0.5816x + 1.4245
r2 = 0.6671
R-2d
y = 0.4166 x + 32.24
r2 = 0.3117
R-28d
- Lab grinding
- Constant sulfates
Villaluenga
14. PE Pyroprocessing II Training
14
SIXTH RULE
+ 10 % C2S + 4 kWh/t
( @ 350 m2/kg )
C2S
A "Hard" to grind:
Increase cement specific griding energy
15. PE Pyroprocessing II Training
15
Lab Cements from Karsdorf ‘ s clinkers
KST = 98
9.8
17.8
26.5
40
50
54
44
30
18.2
11
0
10
20
30
40
50
60
0 10 20 30
Days
KST = 90
9
14.5
23.5
41
54
56
43
24.5
17.3
8.8
0
10
20
30
40
50
60
0 10 20 30
Days
SO3 = 2.3
SO3 = 2.9
MPa
Karsdorf
D
% C3 S +10
% C2 S -10
KWh/t BB10 @ 3500 SSB
KST = 96/98
55
15
41
KST = 90/92
45
25
45 -4
16. PE Pyroprocessing II Training
16
SEVENTH RULE
Alkalies, whatever their form, are never favorable
to 28 day mechanical strength.
Key Figures:
+0.1% Eq Na2O total -1 N/mm² at 28 days
Customer satisfaction
&
Increase cement specific griding energy
17. PE Pyroprocessing II Training
17
45
50
55
60
65
70
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
% Total Alcalies
28
-day
Strength
(MPa)
Influence of Total Alkalies on 28 day
strength
18. PE Pyroprocessing II Training
18
EIGTH RULE
At optimum sulfate content at an early age, soluble
alkalies, especially alkali sulfates, improve early
strength.
Key Figures:
+0.1% Eq Na2O soluble +0.5 to 1.5 N/mm² @ 1 day
Customer satisfaction
19. PE Pyroprocessing II Training
19
1 K2O + 1 SO3 1 K2SO4 SOLUBLE
These soluble alkalies are
Beneficial
for the 1 and 2 days strength
ALKALIES SULFATES
Moles
20. PE Pyroprocessing II Training
20
Plant SSB (m2/kg) 1D (MPa)
Ranteil 400 11.5
375 18.0
Sète 402 11.5
As is
Gypsum addition
As is
Gypsum addition
% SO3 Clinker
0.2
1.1
0.1
1.3
% K2O
Tot
1.15
1.15
0.6
0.6
%Na2O
Tot
0.1
0.1
0.2
0.2 413 17.0
Plant % SO3 Clinker % K2O Total % Na2O Total SSB (m2/kg) 1D str
Martres Gaz 0.20 0.40 0.06 370 12.5
Fuel oil 1.00 350 15.5
La Malle Fuel BTS 0.60 0.95 0.10 360 18.0
Fuel HTS 1.00 340 21.0
Sulfates increase
- Addition in the raw meal
- Increase of fuel sulfur
21. PE Pyroprocessing II Training
21
NINTH RULE
Change of the crystal form of C3A
CUBIC ORTHORHOMBIC
• Worse burnability
• Workability problems
• Sensitivity to aging
• Drop in 28-days strength
ALKALIES and C3A
Customer satisfaction
22. PE Pyroprocessing II Training
22
Na2O + C3A NC8A3
K2O + C2S KC23S12
These alkalies, in conjunction with soluble alkalies
contribute to a reduction of 28 days strength
The excess of alkalies goes
in crystals
…More alkalies than sulfates
23. PE Pyroprocessing II Training
23
% cru
% gypsum SO3 kk
SSB
( cm
2
/ g ) SO3 cem. W / C
Fluidity
(%)
1day str
MPa
Clinker as is 100
0
0,35 3830 2,0 28,6 88 6,5
Gypsum addition 1 97,95
2,05
1,40 3770 2,50 26,0 112 10,5
Gypsum addition 2 96,0
3,95
2,40 3920 2,90 26,2 125 12,5
Cristal form C3A
As is Orthorhombic ( alkalies in cristal )
Gypsed raw mix Cubic ( pure )
Ranteil
Gypsum addition in raw meal (lab test)
24. PE Pyroprocessing II Training
24
SO3kk K20 tot. Na2O tot. SO3
SSB Refus(mm) R 1 j
Après 2’ Après 30’ MPa
As is 0,1 0,37 0,10 2,80 3510 14 29 11,5
Cement (gypsed kk) 2,9 0,56 0,09 2,90 3500 10 19 16,0
Gypsum addition in raw meal
(industrial tests)
Sète
25. PE Pyroprocessing II Training
25
TENTH RULE
If clinker SO3 is increased beyond the
molar saturation of alkalies, an increase in
both clinker fineness and grinding energy
is noted.
Key Figures:
+1% Excess SO3 +5 kWh/t to 350 m²/kg
excess SO3 = SO3 clinker -1.29 (% Eq. Na2O total)
Kiln stability
&
Increase cement specific griding energy
26. PE Pyroprocessing II Training
26
coke coal fuel SO3 kk K2OT Na2OT C/K Mill kW
CPJ 45
F2 F3
1994 47,37 51,01 4,62 0,45 0,75 ~ 0,35 # 0 1,222 38,52
1995 74,14 21,30 3,56 0,95 1,18 ~ 0,35 # 0 1,237 40,29
SO3kk K2OT Na2OT SO3cim Prod SSB # of mill rev
Industriels tests
kk normal 0,1 0,37
Kk (gypsed) 2,9 0,56
0,10 2,8 21 t/h 3150 -
0,09 2,9 17 t/h 2700 -
Lab.tests
kk normal 0,1 0,37
kk (gypsed) 2,9 0,56
0,10 - - 2880 2000
0,09 - - 2580 2000
Excess of Sulfates
* Finish grind kW increase
Sète
Meknès
27. PE Pyroprocessing II Training
27
1991 1992
SO3 kk 0,80 1,45
K2 O 0,89 0,92
Production t / h
(B0) CPA 55
(B3) CPA 55
(B3) CPA HPR
21,6
19,3
14,2
20,3
18,2
13,2
Excess of Sulfates
* Finish grind kW increase
La Couronne
28. PE Pyroprocessing II Training
28
3400
3600
3800
4000
4200
4400
4600
4800
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
SO3 Clinker
Number
of
turns
BB10
y = 1008 x + 3255
R 2 = 0.66
(to reach 350 m2 / kg )
Excess of Sulfates
* Finish grind kW increase
Cantagalo
