The FLSmidth OK Mill Cement and Slag Grinding
Presentation Content
General, Key Points Mechanical features and maintenance Product Quality
Presentation Content
General, Key Points Mechanical features and maintenance Product Quality
OK Roller Mill
OK Mill Capacity Range OPC Cement Mill size OK 45-4 OK 42-4 OK 39-4 OK 36-4 OK 30-4 OK 27-4 OK 25-3 OK 22-3 OK 19-3 0
50
100
150
200
250 t/h
300
350
400
450
OK Mill Capacity Range Slag Mill size OK 45-4 OK 42-4 OK 39-4 OK 36-4 OK 30-4 OK 27-4 OK 25-3 OK 22-3 OK 19-3 0
50
100
150 t/h
200
250
OK Mills Installed and Available Power
Mill size OK 19-3 22-3 25-3 27-4 30-4 33-4 36-4 39-4 42-4 45-4
Motor size (kW) 675 975 1350 1800 2350 3000 3750 4600 5500 6960
Available power is used for capacity calculations in combination with material
Avail. Power (kW) 602 869 1196 1653 2152 2733 3394 4145 4984 5928
OK Mill layout
• Simple and space-saving layout • Proven technology based on a license (1993) from Onoda and Kobe Steel, Japan
• High efficiency separator • Equivalent or better cement quality • Energy saving. 20% to 40% in kWh compared to Ball Tube Mills
• Very suitable for grinding blended cement or slag
• Easily controllable particle size distribution
• Easy maintenance due to swing-in/out roller support system
Separator drive
Mill outlet
OK Roller Mill Details Rotary sluice
Separator rotor Mill feed inlet Separator
Grinding roller
Separator reject Grinding table
Roller stopper Mill stand
Swing out cylinder
Main drive Hydraulic system
Unique design developed specifically or cemen an s ag gr n ng ……
OK Roller Mill – Roller and Table profile
OK Vertical mill grinding parts Pressure distribution
Optimum Design of Rollers and Table 4500
A
Blaine [cm2 /g]
B
Maximum acceptable vibrations
4000
3500
D 3000
0
A B 100
200
Capacity [kg/h]
C
300
C
D
OK Mills vs. Competitor VRM Best Grinding Efficiency
40
/ h W k35 , l a t o T , . s n o C y g r 25 e n E . c e p S20
Spherical roller
OK
Flat roller
15 2500
3000
3500
4000
Blaine
4500
5000
OK mill efficiency compared to ball mills 70
65
For OPC
t 60 / h W k55 , l a t 50 T , . s45 n o C y40 g r e n E35 . c e30 p S
Ball mill ≈ 50 %
OK mill ≈ 33 %
25
20 2500
2700
2900
3100
3300
3500
3700
3900
4100
4300
4500
OK mill versus ball mills Specific energy consumption
EXAMPLES Plant Cement type Type of mill
AA
BB
CC
DD
OPC
OPC
OPC
Slag cement
BM
OK
BM
OK
BM
OK
BM
OK
3200
3200
3700
3700
3880
3900
3640
3640
Mill
32.5
22.2
39.2
21.1
35.2
18.3
34.4
17.2
Total
38.5
28.9
42.3
32.2
42.4
25.7
40.0
25.7
Blaine, cm2/g kWh/t
Conclusion: The energy consumption of the OK mill system is 25% to 40% lower than for the ball mill system
OK mills - Composition of mill feed 100 90 80 70 60 50 40 30 20 10 0 A+B
C
C
D
D
D
E
F+G+ H
I+J
I+J
Plant Clinker, %
Gypsum, %
Limestone, %
Pozzolana, %
Slag, %
Fly ash, %
OK mill performance Entry
Cement type
1 2 3
5 6 7 8
Slag cement OPC OPC Slag cement Slag OPC OPC Blended Blended
10 11 12 13 14 15 16 17 18 19 20
Blended Blended Slag OPC OPC OPC Blended OPC OPC OPC OPC
4
Capacity, t/h Guarant. Achieved 145 192 170 189 170 189 55 60 45 51 66 70 145 161 140 155 170 172 120 150 84 150 152 154 120 180 175 180 180
130 154 91 150 155 166 123 186 194 182 189
Blaine Guarant. Achieved 3670 3550 3000 2900 3000 3300 4000 4105 4000 3982 3800 3800 3000 3060 7% > 45 µ 6.2% > 45 µ 4400 4378 3450 3200 4600 (a) 3300 3800 3750 3450 3000 3000 3200 3200
3900 3650 4210 (b) 3350 4024 3743 3700 3050 3050 3300 3230
kWh/t Garant. Achieved 37.1 28.3 26.3 23.0 26.3 24.3 36.0 34.4 44.0 40.3 34.3 31.0 24.8 21.8 17.2 (Mill) 17.6 (Mill) None 27.4 . 26.8 22.8 22.9 18.3 32.5 (M+S) 31.1 (M+S) 19.7 18.0 36.7 29,4 n/a 29,4 26.8 23.5 29 21.5 n/a 22,6 33 25,4 33 26,0
Easy commissioning of mill First 40 days of OK mill operation 250.0
200.0
5000
4000 3800 - Guar.
Guar. - 168
n150.0 o i t c u d o r P100.0
3000
50.0
1000
0.0
e n i a l B 2000
0
Example of smooth commissioning OK 36 Mill in USA
Cement sales decrease, mill capacity reduced
6000.0
Roller and table liner rewelding 16-19 January 200.0 180.0
5000.0
160.0 .
4000.0
120.0 h /
t , y t 100.0 i c a p a C 80.0
e n i a 3000.0 l B
2
2000.0
Guaranteed performance: 154 t/h; Blaine 3750 cm /g 2 Average achieved over the first 24 weeks: 157 t/h; Blaine 3790 cm /g
60.0 40.0
1000.0
20.0 0.0
0.0 8-1 8-14 8-22 8-28 9-4 9-12 9-18 9-25 10-1 10-7 10-
10-
10- 11-1 11-7 11-
11-
11- 12-4 12-
12-
12-
12-
1-4 1-10 1-22
OK mills recently commissioned Plant
Saloniki 1 Dongjun Dongjun Mojave Lehigh UB Saloniki 2 FFCC Khairpur Maple Leaf 1
Cement type
Blended Slag OPC OPC OPC Blended OPC OPC OPC
Maple Leaf 2 OPC Zlatna Blended (a) Without gypsum
(1) (2) (3) (4)
Capacity, t/h
Duration from 1. start to operation with guaranteed performance
Blaine
Guarant. 120 84 150 152 154 120 180 175 180
Achieved 130 91 150 155 166 123 186 194 182
Guarant. 3450 4600 3300 3800 3750 3450 3000 3000 3200
Achieved 3900 4210 (a) 3350 4024 3743 3700 3050 3050 3300
~ 4 weeks < 3 weeks < 3 weeks ~ 1 week ~ 3 weeks < 2 weeks ~ 1 day ~ 13 weeks ~ 1 week
(1)
180 120
189 138
3200 3650
3230 3702
~ 9 weeks ~ 5 weeks
(3) (4)
Customer’s preference was on other products than contractual fed mix Irregular supply of feed materials from external supplier Same time as kiln – not much focus (first of two mills to start) Problems with transport equipment (client’s supply)
Average duration of commissioning (incl. performance test): 4 weeks
(2)
Run factor similar to the simple Ball Mill 100 90 80 70
% , o t c 50 a f n 40 u R 30 20 10 0
OK mill Ball mill
Operation on 2 rollers – if needed Condition
Production % Res. t/h 45µ
Blaine cm²/g
kWh/t Mill
kWh/t Fan
kWh/t Sep
kWh/t Total
Grinding Aid %
2 rollers
92
3,8
3600
15,2
13,6
0,7
29,4
0,025
4 rollers
144
35
3800
16 1
87
06
25 4
0 025
Guarantee
140
7,0
17,2
0,6
Data from industrial mill OK 33-4.
In case 1 roller is down for maintenance, the mill can continue operating on 2 rollers with a production of app. 65 – 70% of nominal.
features …..
OK mill layout Cement grinding (without slag)
Metal detector
Magnetic separator
The ROKSH The new generation High efficiency dynamic Separator for the OK-Mill
Lower gas velocities Lower energy consumption Cost optimal wear protection
ROKSH main parts
Separator outlet Drive station
Inspection door
Access platforms
Bearing arrangement
Separator casing
Louvres
Coarse return cone
Rotor
Coarse return outlet
Air velocities in the ROKSH Reduced air velocities gives: Less wear Lower differential pressure Lower separator power Reduced mill fan power Overall reduced operation Separator outlet: Through rotor vanes: Through guide vanes: Separator inlet: Mill housing:
19m/s 2.5 m/s 11 m/s 5.4 m/s 2.7-3.8 m/s
ROKSH optimum wear protection Based on experiences with more than 85 ROKS and OKS separators sold Densit Wear flex 2000 wear lining •Separator outlet Hard faced plate (Chromium Carbide) •Separator top section •Coarse return outlet •Rotor vanes •Upper part of reject cone Ceramic Alumina tiles •Separator bearing arrangement •Supports
OK mill -
nozzle ring
Designed to minimize abrasive blasting of key components
OK Mill New Nozzle Ring
OK mill -
nozzle ring
OK Mill - housing/roller seal
Improved roller/housing seal
OK Mill - housing/roller seal Flexible housing/roller seal
Durable Easy to maintain No ingress of false air
OK Mill - rotary feed sluice
Designed for air heating in case of sticky feed materials
OK Mill - rotary feed sluice
Lined with chromium carbide composite wear plate for enhanced durability Removable side walls for ease of maintenance
OK mill - Rotary feed sluice
Dry fly ash injection
Cement Mills - Maintenance Costs Over 4 years
0.8
Over 14 months
0.73 0.7
t /0.6 R U E , s0.5 s o c 0.4 e c n a n0.3 e t n i a0.2 M
0.6
0.42 0.36
0.11 0.1
0
OK mills versus ball mills Maintenance of wear parts (cont’d)
Cost of wear parts: OPC, 3200 – 3600 cm /g (Blaine) Ball mills OK mills
EUR per ton of cement 0.15 – 0.20
Hardfacing not applied
0.15 – 0.20
Hardfacing applied
0.10 – 0.15
Maintenance of wear segments Extensive wear
⇒
Deterioration of performance:
Lower capacity
Higher specific energy consumption
Higher level of vibrations
Remedy of wear:
(Reversal of roller segments)
Hardfacing of roller and table segments – by far the preferred method
OK Mill - Typical Wear Pattern
Hardfacing of rollers and grinding table
Dual headed welding gun
Roller being hardfaced in situ
Hardfaced Roller OK 27-4
OK 2727-4 Hardfacing after 350 Hours of Operation
Segments vs. Tyres • No risk of thermal cracking during operation/welding • Numerous re-welding’s possible (typical ~ 10) • Lower lifetime cost
Hydraulic maintenance cylinder A maintenance cylinder with a separate pump station is supplied for swinging out the rollers. This gives easy access to maintenance/replacement of segments etc.
Lifetime of wear parts. 1 Clinker grinding: A typical wear rate is around 1 g/t giving a life time of around 12.000 hours without hardfacing. Hardfacing usually reduces wear to about 50%. Hardfacing can usually be performed up to 10 times on the rollers, and 25 times on the table has been achieved. Typical example: OK 27-4 clinker 3800-4000 Blaine Mill start
05/1999
Hours Ton
Reversal
08/2000
8336
Table hardfacing
12/2000
10300 662883
g/t
547098 0,76
Product quality
OK mill – product quality Plant Cement type Mill Fineness . PSD Blaine(m2/kg) Res. 45 µm (%) PSD / d-50% (µm) PSD / d’ (µm) Dehydr./Prehydr. Gypsum (%) Hemihydr. (%) Prehydr. (%) Cement testing (EN / ISO) Water to NC (%) Initial set (h:min) Final set (h:min) Str.-1day (MPa) Str.-2 days (MPa) Str.-3 day (MPa) Str.-7 day (MPa) Str.-28 day (MPa)
Plant A OPC
Plant B Blended RP+BM-2 OK-1
OK-2
Plant C Blended RP+BM OK
BM
OK
RP+BM-1
375 5.3 13.4 17.7 .
377 1.3 12.0 16.3 .
399 5.4 13.6 18.6 .
436 5.6 12.8 17.8 .
399 7.4 14.1 19.4 .
376 4.5 14.9 19.5 .
437 2.4 11.7 16.3 .
385 3.2 13.0 17.6 .
0.1 1.5 0.25
2.0 0.5 0.15
1.2 2.3 -
0.9 2.3 -
1.9 1.7 -
3.2 1.0 -
4.0 2.0 0.29
3.5 1.5 0.20
27.0 2:05 2:50 19.0 27.6
26.5 1:50 2:40 18.8 28.8
29.5 2:35 3:20 13.8
29.0 2:25 3:10 12.1
31.0 3:05 4:00 10.6
32.5 3:15 4:20 10.2
27.5 1:20 2:30 15.5 32.1
27.5 1:45 2:30 14.8 32.5
39.0 60.5
42.8 60.3
29.8 39.4 50.0
28.4 36.1 47.9
26.9 35.7 49.2
28.8 37.5 50.3
39.8 50.5
41.7 52.0
Conclusion: Quality of cements produced in OK
OK Mill - Particle Size Distribution Inclination of PSD Curve n (RRSB) Height of dam ring
Airflow [%]
1,4
1,3
100
Low
1,3
1,2 Medium
1,2
High
1,1
83 89 100 Grinding pressure [%] 78
80
1,1
1,0
80 100 60 Separator speed [%]
OK Mill - Dam Ring and Nozzle Ring
Cement grinding
Segmented dam ring, easy to adjust in height
Dam ring height
Grinding pressure
Low
High
Cement Quality / Particle Size Distribution
Effects of steeper (narrower) PSD : • Cement properties : -
eeper s reng
eve opmen curve
- Higher (late) strength at fixed Blaine - Lower (early) strength at fixed sieve residue (45 µm) - Higher water demand for normal consistency of paste but not necessarily for concrete
Comparison of cement quality
Ball Mill ( BM (CM1 )): UM 42 x 13 with Sepax IC-335 Vertical Roller Mill ( OK ) : OK 27-4
Plant A
Cements
Ordinary Portland Cement (OPC) Clinker : 96 % Gypsum : 4% SSA (Blaine) : 370 m2/kg
Cements . Plant A Particle Particle Size Distribution (RRSB-grid) 0.1 1 5 10 20 ) 30 ( 50 60 e 70 u d i 80
BM (CM1) OK
s e 90 R 95 96 97 98 99
0.1
1
10 Particle size (µm)
100
1000
Cements . Plant A
Fineness data Spe cific Surface (Blaine ) : m2/kg Air Jet Sieving : 90 µm % 63 µm % 45 µm % 32 µm % Lase Laser Diffrac Diffr action tion : d(50%) µm d'-RRSB µm n-RRSB Sm m2/kg
BM (CM 1)
OK
375
377
0.2 1.2 5.3 15.1
0.1 1.3 9.3
13.4 17.7 1.05 367
12.0 16.3 1.10 372
Cements . Plant A
Setting
BM (CM 1)
OK
Wate r to N.C. Initial se t
% h:min
27.0 2:05
26.5 1:50
Final se t
h:min
2:50
2:40
Cements . Plant A
Compressive strength 70
) a P 60 M ( ] 6 9 1 50 N E [ h t 40 g n e r t 30 s e v i s 20 s e r p m10 o C
BM (CM1) OK
0
1d
2d
7d
28d
Cement Quality / OK mills
OK Mill - Ball Mill comparisons Conclusion :
OK mill and a ball mill unit producing cement from the same raw materials have indicated, that the OK mill cements tended to have a slightly steeper (narrower) particle size distribution and a lower dehydration level of the gypsum. However, the resulting cement properties were similar to those of the cements produced in the ball mill installations.
Final remarks
Repeated sale of OK mills after commissioning of customer’s first OK mill Customer Chettinad Loma Negra
Plant
Country
Year
Mill size
Polyiur
India
1996
OK 36-4
Palayam
India
1999
OK 36-4
Ecorama
Argentina
1996
OK 27-4
Catamarca
Argentina
2008
OK 33-4
Juan Minetti, Campana Apasco, Ramos Arizpe Faraz Firouzkuh Ste. Genevieve
Argentina Mexico Iran USA
1996 1999 1998 2000 2003 2006
OK 33-4 OK 33-4 OK 36-4 Ok 36-4 OK 36-4 4 x OK 36-4
Boyaca
Columbia
2008
OK 36-4
Kamari
Greece
1998
OK 27-4
Saloniki
Greece
Zlatna
Bulgaria
2002 2005 2005
OK 30-4 OK 30-4 OK 30-4
Tanda
India
2002
OK 30-4
,
Holcim
Titan Cement
Jaypee Cement
Sale of ball mills and VRM for cement grinding ex. China 80
70
60 d l o s 50 s l l i m f 40 o r e b m30 u N
20
10
0
BM VRM
Summary of Experience with OK Mills commissioned by F.L.Smidth
All the mills have proved capable of producing above the guaranteed output at the required fineness
Their spec. energy consumption is at or below the estimated low level
The OK mill has proved suitable for grinding not only slag and Ordinary Portland Cement, but also blended cements with a wide range of additives such as slag, pozzolana, limestone and fly ash.
Summary of Experience with OK Mills commissioned by F.L.Smidth (cont’d)
The mill’s operational parameters can be adjusted to attain an end product that complies with the client’s specific requirements
During maintenance of one or two rollers, the mill can continue to operate with two rollers only, at a somewhat reduced capacity
The mill is reliable in operation, easy to operate and easy to maintain
OK mills sold – Marts 2010
OK
OK OK OK OK OKOKOK OK OK OK OK OK OK OK OK OK OK OK
OK OK OK OK OK OK OK OK
OK OK
OK OK OK OKOK OK
OK OK OK OK OK OK OKOK OK OK OK OK OK OK OK
O
OK OKOK OK
OK OK OK OK
OK OK OK OK OK OK OK OK OK OK OK OK
OK OK
OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK
