This document provides information on trends in the cement production process, including moving towards larger production units, lower energy consumption, and increased use of alternative fuels. It discusses the history of development of different kiln technologies over time, from wet kilns to modern preheater and precalciner kilns. Details are given on specific kiln systems like the Rotax, SLC, and ILC designs. Charts and diagrams show aspects like typical heat balances and consumption rates for different process stages.

1. 06-08-28
Cement Plant
Cement Plant Pyro
Pyro-
-Technology
Technology
Palle Grydgaard
MSc, Chem. Eng.
Head of Process, PD1-P1
F.L.Smidth A/S
Vigerslev Allé 77 • DK-2500 Valby • Copenhagen • Denmark
Tel +45 36 18 10 00 • Direct line +45 36 18 20 63
Fax +45 36 17 10 91
palle.grydgaard@flsmidth.com

2. 06-08-28
Trends in cement process:
Trends in cement process:
• dry process
• larger production units
> 5.000 t/d up to 12.000 t/d
• lower energy consumption
<720 kcal/kg (<90 l oil/t) and <90 kWh/t
• more alternative materials and fuels
waste (pet coke, tyres, solvents, bone meal etc.)
• more automation for better quality
• more focus on the environment
emissions (NOx, SOx, dust, noise etc.)

3. 06-08-28
Wet Kilns
1898: 1.8x18m
35 tpd
1967: 7.6x232 m
3500 tpd
Preheater kilns
1970: 6.0x96 m
4000 tpd
Precalciner kilns
1984: 5.0x80 m
5500 tpd
1990: 6.0x96 m
≥10,000 tpd
2006: 6.6x93 m
>12.000 tpd
History of kiln capacity development
History of kiln capacity development

4. 06-08-28
Rotax
Rotax-
-2 kiln for 5500 tpd
2 kiln for 5500 tpd

5. 06-08-28
SLC
SLC -
-
Separate
Separate
Line
Line
Calciner
Calciner
10000
10000 t/d
t/d

6. 06-08-28
Kiln heat consumption (1 kcal/kg = 4.18 kJ/kg)
Process kcal/kg
Wet process with chains +/- cross ~1400-1600
Long dry process with chains +/- cross ~1100
1-stage cyclone preheater ~1000
2-stage cyclone preheater ~900
4-stage cyclone preheater ~800
4-stage preheater+precalciner+SFcooler ~735-750
5-stage preheater+precalciner+SFcooler ~710-730
6-stage preheater+precalciner+SFcooler <700

7. 06-08-28
Main Raw Material: Limestone

8. 06-08-28
TYPICAL
Values
Clinker Raw Mix Limestone Clay Iron ore
Mix %dry 83.92 13.31 2.77
SiO2 %
Al2O3 %
Fe2O3 %
CaO %
MgO %
K2O %
Na2O %
LOI %
21.06
4.87
4.70
64.39
1.94
0.57
0.34
13.77
3.19
3.07
42.11
1.27
0.37
0.22
34.61
5.19
1.41
1.34
49.48
1.11
0.16
0.07
39.73
64.06
13.96
5.95
2.18
1.42
1.72
1.03
9.51
32.20
5.22
41.91
10.69
5.41
0.33
1.03
Total 98.83 98.83 98.69 100.00 97.37
LSF %
MS
MA
95.00
2.20
1.04
95.00
2.2
1.04
289.92
1.89
1.05
1.09
3.22
2.36
8.65
0.68
0.12
C3S %
C2S %
C3A %
C4AF %
62.8
13.2
4.95
14.3

9. 06-08-28
Calcination Reactions
CaCO3 = CaO + CO2
Al2O3, 2 SiO2, 2 H2O = Al2O3, 2 SiO2 + 2 H2O

10. 06-08-28
Chemical changes during burning
Liquid phase
Free CaO
CaCO3
Quartz
Clays
C S
2
C S
3
C A
3
C AF
4

11. 06-08-28
ILC
ILC -
- In
In-
-Line Calciner
Line Calciner

12. 06-08-28
SLC
SLC-
-D Separate
D Separate Calciner
Calciner -
- Downflow
Downflow

13. 06-08-28
Modern Dry Process Kilns
Plant
Name
Kiln
size
DxL, m
L/Di Load
t/d/m3
Prod.
t/d
Heat
Cons.
Kcal/kg
Remarks
Ozarow 5.75x92 17 4.3 8500 ~750 4 stage preheater + ILC
+ 3 supports + grate cooler
Siam City 6.0x96 17 4.3 10000 ~720 5 stage preheater + SLC
+ 3 supports + grate cooler
Zuari 4.55x68 16 5.7 5200 ~730 4/6 stage preheater + SLC
+ 3 supports + grate cooler
Sean Quinn 4.55x54 13 5.2 3800 ~735 5 stage preheater + ILC
+ 2 supports + grate cooler
Saloniki 4.55x58 14 4.5 3500 ~720 5 stage preheater + ILC
+ 2 supports + SF cooler
Ramos 4.55x56 13.5 4.2 3150 ~700 6 stage preheater + ILC
+ 2 supports + SF cooler

14. 06-08-28
Heat
Consumption
kcal/kg (kJ/kg)
SURFACE HEAT LOSS FROM KILN 30 (125)
SURFACE HEAT LOSS FROM PREHEATER 35 (146)
COOLER LOSS 115 (481)
EXIT GAS HEAT LOSS 145 (606)
HEAT OF REACTION 400 (1673)
FREE INPUT WITH RAW MEAL + FUEL - 25 (- 105)
NET HEAT CONSUMPTION 700 (2927)
TYPICAL HEAT BALANCE:
6-STAGE MODERN KILN SYSTEM

15. 06-08-28
Maximum utilization of kiln
exhaust gases - 100 % to raw mill 5 stage ILC 6 stage ILC
Kiln heat consumption 725 kcal/kg cl 700 kcal/kg cl
Exhaust gas temperature 312 0C 280 0C
Exhaust gas quantity 2.18 kg/kg cl 2.16 kg/kg cl
Drying capacity in a vertical roller mill
running 20 hours/day
(ambient temperature of 15 0C)
8.6 % H2O 7.3 % H2O
Drying capacity in a vertical roller mill
running 20 hours/day
(ambient temperature of 0 0C)
7.4 % H2O 6.2 % H2O

16. 06-08-28
High-
temperature
ILC low-NOx
Calciner
Reduction
zone (1100°C)
Air from cooler
(3’ air)
Kiln gas
High-temperature
oxidation zone
(1100°C)
Calcination
zone (900°C)
CO eliminating
duct
Stage 2
cyclone
Stage 3
cyclone
Stage 4
cyclone
(880°C)
Calciner
fuel input

17. 06-08-28
Two string
Two string
ILC Low
ILC Low-
-
NOx
NOx
precalciner
precalciner

18. 06-08-28
Upgrading of
Upgrading of
3500 tpd
3500 tpd
preheater kiln to
preheater kiln to
two
two-
-string ILC
string ILC
Low NOx
Low NOx
precalciner
precalciner
system
system
designed for
designed for
8500 tpd
8500 tpd

19. FLS
SLC - D
Calciner

20. 06-08-28
SLC
SLC-
-D
D

21. 06-08-28
5500 tpd
SLC-D
precalciner
system
designed for
100%
petcoke
firing

22. 06-08-28
FLS Standard Rotary Kiln Dimensions
FLS Standard Rotary Kiln Dimensions
FLS 2-base kiln
FLS 3-base kiln
13 x D inside lining
2.3 x D 6.8 x D 3.6 x D
17 x D inside lining
1.3 x D 5.3 x D
6.4 x D 2 x D
ø
D
ø
D

23. 06-08-28
Inlet & Outlet Lamella Seals
Inlet & Outlet Lamella Seals

24. 06-08-28
Duoflex kiln burner
Duoflex kiln burner
Primary air inlet
Burner trolley
Burner pipe with
refractory
Valve for radial air Valve for axial air

25. 06-08-28
waste oil
wood chips
or plastic
chips
fuel oil
pulverised
coal
plastic chips or oil contaminated refuse
>>>
DUOFLEX BURNER FOR ALTERNATIVE FUELS
DUOFLEX BURNER FOR ALTERNATIVE FUELS

26. 06-08-28
Waste Fuel: An opportunity
Waste Fuel: An opportunity

27. 06-08-28
THE (SMIDTH-FULLER)
SF CROSS-BAR™ COOLER

28. 06-08-28
Stationary and Moveable Cross-Bars

29. 06-08-28
Stationary and Moveable Cross-Bars

30. 06-08-28
Air flow through
Air flow through
holes in tongue
holes in tongue
Air flow through
Air flow through
idle hole
idle hole
Air flow through
Air flow through
gaps
gaps
AIR DISTRIBUTION PLATE WITH MFR
AIR DISTRIBUTION PLATE WITH MFR
∆P
ρ
ξ
Q
A
A
Q
ρ
ξ
ρV
ξ
∆P
2
2
1
2
1
2
2 &
&
=
⇒
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
=

31. 06-08-28
Mechanical Flow Regulators
Mechanical Flow Regulators
HIGHER
VALVE dP
LOW BED
RESISTANCE
HIGH BED
RESISTANCE
LOWER
VALVE dP
C O N S T A N T A I R F L O W

32. 06-08-28
5 stage ILC kiln
Fuel Type Bituminous
Coal
Heavy
Fuel
Oil
Natural
Gas
Net Heat Value
kcal/kg fuel
6430 9780 11300
Kiln Heat Cons.
kcal/kg clinker
727 720 731
CO2 from Raw Mat. kg/kg clinker
CO2 from Fuel kg/kg clinker
0.540
0.281
0.540
0.230
0.540
0.174
Total CO2 kg/kg clinker 0.821 0.770 0.714

33. 06-08-28
TYRES

34. 06-08-28
HOTDISC
HOTDISC
DESIGN
DESIGN
CONCEPT
CONCEPT

35. 06-08-28
HOTDISC

36. 06-08-28
Hotdisc
connected
to calciner