The FLSmidth OK millThe high-effiency and reliable roller mill for cement
and slag grinding
FLSmidth – Slide 1
First FLSmidth vertical mill (1922)
FLSmidth – Slide 2
ATOX Raw Mill
FLSmidth – Slide 3
• Simple and space-saving layout
• Proven technology based on alicense (1993) from Onoda and
Kobe Steel, Japan
• High efficiency separator
• Equivalent or better cement quality
OK Mill layout
FLSmidth – Slide 4
• Equivalent or better cement qualitythan tube mill cement
• Energy saving. 25% to 45% in kWhcompared to Ball Tube Mills
• Very suitable for grinding blendedcement or slag
• Easily controllable particle sizedistribution
• Easy maintenance due toswing-in/out roller support system
FLSmidth OK mill
Separator
Grinding roller
Separator drive
Mill outlet
FLSmidth – Slide 5
Rocker arm
Gear box
Mill stand
Mill feed inlet
Grinding table
Hydraulic system
OK Mill - a Unique design developed specifically fo r cement and slag grinding ……
FLSmidth – Slide 6
OK Vertical mill grinding partsPressure distribution
FLSmidth – Slide 7
OK mill efficiency compared to ball mills
50
55
60
65
70
Spec. Energy Cons.,Tota
l, kW
h/t
Ball mill
FLSmidth – Slide 8
20
25
30
35
40
45
2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 4500
Blaine, cm2/g
Spec. Energy Cons.,Tota
l, kW
h/t
OK mill
≈ 33 %
≈ 45 %
Raw material preparation
38%Cement grinding
44%
Cement storage / dispatch
1%
with OK mill
Importance of cement grinding on total plant power consumption
FLSmidth – Slide 9
Clinker production
17%
Raw material preparation
44%
Clinker production
19%
Cement grinding
36%
Cement storage / dispatch
1%
with ball mill
with OK mill
CO2 reduction substituting ball mill with OK mill
Example
40,000
50,000
60,000
CO2 reduction, t CO2 per year
Clinker production capacity: 1.5 mill t/yearCement type: Ordinary Portland CementEF = Emission Factor (tCO2/MWh)
EF = 1.0
EF = 0.75
FLSmidth – Slide 10
0
10,000
20,000
30,000
2500 3000 3500 4000 4500 5000
Blaine, cm2/g
CO2 reduction, t CO2 per year
EF = 0.5
Clinker replacement materials for blended cement
It is good for the environment:
• Saving of raw materials
• Energy saving
• Reduced CO2 emission
• Waste utilization (slag and fly ash)
FLSmidth – Slide 11
OK mill is very suitable for grinding of blended cement:
• It is more versatile than a ball mill. Separate drying facilities are not required. It is easy to change from one product type to another product with practically no transition periods between products.
• Besides pure slag it can grind any type blended of cement with additives such as limestone, pozzolana, fly ash and slag; even with high water content
50
60
70
80
90
100
OK mills - Composition of mill feed
FLSmidth – Slide 12
0
10
20
30
40
A+B C C D D D E F + G +H
I + J I + J
Plant
Clinker, % Gypsum, % Limestone, % Pozzolana, % Slag, % Fly ash, %
Entry Cement type Capacity, t/h Blaine kWh/t Guarant. Achieved Guarant. Achieved Garant. Achieve d
1 Slag cement 145 192 3670 3550 37.1 28.3 2 OPC 170 189 3000 2900 26.3 23.0 3 OPC 170 189 3000 3300 26.3 24.3
Slag cement 55 60 4000 4105 36.0 34.4 4
Slag 45 51 4000 3982 44.0 40.3 5 OPC 66 70 3800 3800 34.3 31.0 6 OPC 145 161 3000 3060 24.8 21.8 7 Blended 140 155 7% > 45 µµµµ 6.2% > 45 µµµµ 17.2 (Mill) 17.6 (Mill) 8 Blended 170 172 4400 4378 None 27.4
+ 9 % + 3 % - 14 %
OK mill performance
FLSmidth – Slide 13
8 Blended 170 172 4400 4378 None 27.4 9 OPC 118 144 3900 3900 - 25.7
10 Blended 120 130 3450 3900 26.8 22.8 11 Blended 150 154 3200 3650 22.9 18.3 12 Slag 84 91 4600 (a) 4210 (b) 32.5 (M+S) 31.1 (M+S) 13 OPC 150 150 3300 3350 19.7 18.0 14 OPC 152 155 3800 4024 36.7 29,4 15 OPC 154 166 3750 3743 n/a 29,4 16 Blended 120 123 3450 3700 26.8 23.5 17 OPC 180 186 3000 3050 29 21.5 18 OPC 175 194 3000 3050 n/a 22,6 19 OPC 180 182 3200 3300 33 25,4 20 OPC 180 189 3200 3230 33 26,0 21 Blended 120 138 3650 3702 27 20,0
(a): With gypsum (b): Without gypsum
150.0
200.0
250.0
3000
4000
5000
3800 - Guar.
Guar. - 168
Easy commissioning of millFirst 40 days of OK mill operation
FLSmidth – Slide 14
0.0
50.0
100.0
150.0
2/1 2/3 2/5 2/7 2/9 2/11 2/14 2/16 2/18 2/20 2/22 2/24 2/26 2/28 3/3 3/5 3/7
Date, 2006
Pro
duct
ion
0
1000
2000
3000
Bla
ine
OK mill – product quality
Plant Plant A Plant B Plant C
Cement type OPC Blended Blended
Mill BM OK BM-1 BM-2 OK-1 OK-2 BM OK
Fineness . PSD
Blaine(m2/kg) 375 377 399 436 399 376 437 385
Res. 45 µm (%) 5.3 1.3 5.4 5.6 7.4 4.5 2.4 3.2
PSD / d-50% (µm) 13.4 12.0 13.6 12.8 14.1 14.9 11.7 13.0
PSD / d’ (µm) 17.7 16.3 18.6 17.8 19.4 19.5 16.3 17.6
PSD / n-value 1.05 1.10 1.11 1.07 1.07 1.06 1.01 1.05
FLSmidth – Slide 15
PSD / n-value 1.05 1.10 1.11 1.07 1.07 1.06 1.01 1.05
Dehydr./Prehydr.
Gypsum (%) 0.1 2.0 1.2 0.9 1.9 3.2 4.0 3.5
Hemihydr. (%) 1.5 0.5 2.3 2.3 1.7 1.0 2.0 1.5
Prehydr. (%) 0.25 0.15 - - - - 0.29 0.20
Cement testing (EN / ISO)
Water to NC (%) 27.0 26.5 29.5 29.0 31.0 32.5 27.5 27.5
Initial set (h:min) 2:05 1:50 2:35 2:25 3:05 3:15 1:20 1:45
Final set (h:min) 2:50 2:40 3:20 3:10 4:00 4:20 2:30 2:30
Str.-1day (MPa) 19.0 18.8 13.8 12.1 10.6 10.2 15.5 14.8
Str.-2 days (MPa) 27.6 28.8 32.1 32.5
Str.-3 day (MPa) 29.8 28.4 26.9 28.8
Str.-7 day (MPa) 39.0 42.8 39.4 36.1 35.7 37.5 39.8 41.7
Str.-28 day (MPa) 60.5 60.3 50.0 47.9 49.2 50.3 50.5 52.0
Conclusion: Quality of cements produced in OK mills is very similar to those produced in ball mills with high efficiency separators
50
60
70
80
Num
ber
of m
ills
sold
Sale of ball mills and VRM for cement grinding ex. China
FLSmidth – Slide 16
0
10
20
30
40
Num
ber
of m
ills
sold
2003 2004 2005 2006 2007
BMVRM
OK mills sold – July 2008
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All together 92 FLSmidth OK mills sold world wide
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Summary of experiences with OK Mills commissioned by FLSmidth
• The production is above guaranteed
• The spec. energy consumption below guaranteed
• It grinds all kind of cements with additives
FLSmidth – Slide 18
• It grinds all kind of cements with additives
• The operational parameters can be adjusted to meet quality requirements
• It can be operated with two rollers only
• It is reliable in operation, easy to operate and easy to maintain
Thank you for your attention
FLSmidth – Slide 19