A slide on Rolling Oil Emulsion Management, prepared and presented in a servo oil meet held in 2016 at Kolkata

1. ROLLING OIL
EMULSION
MANAGEMENT
BY EJAJ AHMAD
G.M.(OPERATION)
BHUSHANPOWER&
STEELLTD,KOLKATA

2. NEED OF ROLLING OIL
 TO PROVIDE LUBRICITY AT ROLL
BITE.
 TO PROVIDE COOLING EFFECT TO THE
W/P (ROLLED SHEET) AND TOOLS
(ROLLS)
 RUST PREVENTION ( PROTECT SHEET
AND ROLLS FROM RUST)

3. EFFECTS OF ROLLING OIL
• Rolling oil is one of the major consumables in
rolling process. Although it has a contribution of
only 5% of total process cost, but directly or
indirectly it plays major role in achieving 95% of
rolling target like :
 Process Optimization (95% of Process Efficiency)
 Improvement in Surface Finish (95% of standard
deviation in Thickness)
 Shape Improvement (Flatness of 10~15 in “I Value”)
 Surface Appearance (95% of surface are defect free )

6. FORM OF ROLLING OIL EMULSION
ROLLING OIL EMULSION CONSISTS OF OIL
AND WATER :
ROLLING OILEMULSION RO/DM WATER

7. TYPES OF EMULSION
O/W [OIL in WATER]
OIL IN WATER
EMULSION COMPRISES
OF OIL DROPLETS
SUSUPENDED IN AN
AQUEOUS PHASE
(WATER PHASE)
EXAMPLE : Moisturizers, Milk
Products, M/c tool coolant
and Rolling oil Coolant
FEATURE : Optimum Lubricity
and more cooling
• W/O [WATER IN OIL]
WATER IN OIL EMULSION
COMPRISES OF WATER
DROPLETS SUSPENDED IN
CONTI-NOUS OIL PHASE
EXAMPLE : Make-up Products,
Sunscreen etc.
FEATURE : High Lubricity and
less cooling

8. ALL EMULSIONS
WHETHER O/W OR W/O
REQUIRE AN EMULSIFIERS
TO PROVIDE THEM WITH
OPTIMAL STABILITY

9. BENEFITS OF GOOD ROLLING OIL
 REDUCES ROLLING FORCE REQUIRED TO
DEFORM THE METAL RESULTING IN LOWER
ENERGY CONSUMPTIOM
 REDUCES STRIP AND ROLL TEMPERATURE
RESULTING IN SHAPE IMPROVEMENT AND
INCREASES ROLL LIFE BY REDUCING ROLL
WEAR
 ACHIEVING HIGH QUALITY SURFACE

10. COMMON ELEMENTS OF ROLLING OIL
 LUBRICANT BASE (80% - 90%)
– Natural Oils
– Mineral Oils
– Synthetic Oil
 BOUNDARY ADDITIVES
– Molecules with permanent dipole moment like derivatives of
fatty oils (acids, alcohol, amines)
– Natural soaps of Easters

11. EMULSIFIERS
– Emulsion stability
– Oil particle size
– Plate Out
– Shear stability
 EP ADDITIVES
 DISPERSANT
 SURFACTANTS
REMARK : BASE OIL PLAYS MAJOR ROLL IN SELECTION OF OPTIMUM
ROLLING OILS FOR COLD ROLLING
.

13. A lubricity base containing mineral oils, esters,
polar additives and extreme pressure (EP) additives
■ The emulsifier package, which mainly influences
the emulsion stability (particle size), the lubricity via
plate out and the detergency
■ Sulphur compounds, which are very important in
order to improve the evaporation behaviour in
annealing. They also improve lubricity
■ Corrosion inhibitors to prevent staining of cold
rolled strip
■ Antioxidants to maintain bath life of an emulsion
and to reduce the effects of oxidation of rolling oil
residues remaining on the warm coil after cold
rolling

14. CHARACTERISTICS OF BASE OIL
Base Oil must meet the following Criteria
 Good Lubricity
 Oxidation Stability (Anti oxidant)
 High Velocity Index
 High Temperature Index
 Chemical Stability &
 Hydrolytic Stability

16. • LOOKING AFTER ABOVE CRITERIA OF ROLLING
OIL, THE SELECTION OF BASE OILS ARE
ARRANGED IN QUALITY WISE INCREASING
ORDER.
• PALM OIL > NATURAL OIL > MINERAL OIL >
SYNTHETIC ESTERS
• SYNTHETIC ESTERS ARE MORE ACCEPTIBLE,
WHICH MEETS ALL REQUIRED CRITERIA OF
TODAYS REQUIREMENTS IN COLD ROLLING
PROCESS.

17. SYNTHETIC ESTERS
CARBOLYXLIC ACID + ALCOHOLS

18. IMPOTRANT NOTES :
• While converting Acid and Alcohols mixture into the
Esters, some part of Free Fatty Acid (FFA) remains in
the mixture, which is denoted by ACID NO.
• Every Rolling oils have some Acid No, to be specified
and declared by oil manufacturer in their test
certificate.
• Increase in acid no denotes the increase in FFA, which
could be the detrimental if not controlled because it
breaks the bond of esters and lastly it may loss it
desired properties.
• Acid no is the trigger point for the maintenance of
rolling oil emulsion, which should not be more than 1.5
to 2 times of Acid no specified by the manufacturer.

19. EMULSION MANAGEMENT
WHY ?

20. GOOD EMULSION MANAGEMENT PROVIDES :
 Consistent Performance of Oil
 Longer Emulsion Life
NOTE : Performance of Emulsion greatly
depends upon the proper balanced
Emulsion Stability along with the presence
of all performing additives and Emulsifiers.

21. EMULSION PARAMETERS
Following elements of the emulsion to be
managed to maintain Emulsion Stability or
Emulsion Healthiness.
 Oil Concentration
 Temperature
 Conductivity
 ESI / Particle Size
 Tramp Oil
 Chloride
 Acid Value
 SAP Value
 Iron Fines

22. Rolling Oil Solution Management
EMULSION PARAMETERS OPERATING
RANGE & ITS TESTING

23. Rolling Oil Solution Management
Recommended use parameter
Concentration: 3.0 % to 3.50%
pH of 3% solution in DM water: Depends on product selection
(+/-0.5-1.0)
Emulsion Conductivity: <500 micro S/cm
Temp: 500 to 600 C
Fe Content: <200 ppm
Chloride: < 50 PPM
Chloride in Pickling Rinse Water < 50 PPM
Chloride on Pickled Strip < 0.30 mg/m2
% Tramp: < 15% (Preferably <10%)
Oil on CR Strip < 100 mg/m2
Carbon CR Strip < 7 mg/m2
Bacteria < 5x105
Acid Value < two times in Oil

24. Rolling Oil Solution Management
Rolling Oil Solution Testing Parameters & Frequency:
Solution Temperature : Once in every Shift
Solution pH: Once in every Day
Solution Conductivity: Once in every Day
Oil Concentration: Once in every Day
Chloride Content: Once in every Day
Iron Content: Twice in a Week
Saponification Number & Tramp Oil of extracted oil: Twice in a week
Acid Number of extracted oil: Twice in a week

25. Rolling Oil Solution Management
Water Testing Parameters & Frequency:
RO Water pH: ( 6.0 – 7.0 ) Once in a day
RO Water Conductivity: ( 60 µs / cm. max ) Once in a day
RO Water Chloride: ( 15 ppm max) Once in a day
RO Water Total Hardness ( 10 ppm max ) Once in a day
Data Analysis
Solution analysis records are also important. Quality of RO water depends upon
effective running of RO plant and its regular maintenance.

26. Rolling Oil Solution Management
Impact of Solution Parameters

27. Oil Concentration
Too high (>4.5%)
• Over Lubrication
• Too low Roll Force
• Skidding
• Very High plate out – Affect
surface quality after
Annealing or un-coating issue
in Galvanizing
Too low (<1.5%)
• High Roll Force
• Gauge variation
• Inadequate lubrication
• Lower stability
• Low speed
ADDITION of OIL: Daily addition of oil to be
maintained on regular basis to ensure the
concentration in range of 3 – 3.5 %.

28. Oil Concentration
• Variation in actual production line may be high
owing to :
-Disproportionate oil addition.
-Evaporation of water.
-Change in emulsion characteristics of oil.
-Skimming of tramp oil.
• Online oil concentration measurement helps:
- The oil content directly relates to the velocity of sound in
the fluid. A change of 1% oil content brings about an
change of approx. 2m/s.

29. Sp. Conductivity
Conductivity is a measure of water's capability to pass electrical flow. This ability
is directly related to the concentration of ions in the water 1. These conductive
ions come from dissolved salts and inorganic materials such as alkalis, chlorides,
sulfides and carbonate compounds
1 μS/cm is then equivalent to about 0.64 mg of NaCl per kg of water.
• Major contributors: H+, OH-, Cl-, SO4
2-
• Minor contributors: Ca2+, Mg2+, Na+, K+
Too high (>800)
• Emulsion Un-stable
• Differential Lubrication
• Contamination on rolled
surface
• Risk for corrosion
• Higher oil consumption due to
more bottom draining
Too low
• Possibility of foaming

30. Temperature
Too high (>65)
• Emulsion Un-stable
• Over lubrication/
Differential Lubrication
•Thermal Hydrolysis
Too low (<45)
• Inadequate
lubrication
• Bacterial growth
• Affect emulsion
stability
Higher emulsion temperature than desired:
- Brings down oil film thickness by decreasing viscosity.
- Declines cooling efficiency.
- Emulsifier’s behavior may get affected.

31. pH
A figure expressing the acidity or alkalinity of a solution on a
logarithmic scale on which 7 is neutral, lower values are more acid and
higher values more alkaline. The pH is equal to −log10 c, where c is the
hydrogen ion concentration in moles per litre.
Emulsifier System is pH Sensitive.
Cause of pH disturbances
- Acid carry over from pickling line
- Inferior feed water for emulsion
- Tramp Oil mixing
Too high (>6.5)
• Higher emulsion stability
• Less Lubrication
• High Roll Force
• Gauge variation
• Low speed
Too low (<4.5)
• Over Lubrication/ Differential
Lubrication
• Too low Roll Force
• Skidding
• Very High plate out – Affect surface
quality after Annealing or un-coating
issue in Galvanizing

32. Iron Content
Too high (>500 mg/ ltr)
• Contamination on rolled
surface
• Affect surface quality
after Annealing or un-
coating issue in Galvanizing
• Higher oil consumption
due to more magnetic
separator running &
bottom draining Too low (<100 mg / ltr)
• Inadequate
lubrication
• High Roll Force

33. Chloride Content
Too high (>200 ppm)
• Emulsion Un-stable
• Contamination on rolled
surface
• Risk for corrosion
• Higher oil consumption :
more bottom draining Too low
• No problem,
desirable condition

34. Tramp Oil
Oil in emulsion that doesn’t derive from the emulsion
concentration itself is uncontrollable and therefore
undesirable.
Too high (> 15%)
 Inadequate lubrication
 High Roll Force
 Higher oil consumption due to
more skimming
 Affect surface quality &
cleanliness Too low
 No problem, desirable condition

35. Negative effects of Tramp Oil:
• Loss of cooling & wetting properties.
• Deplete emulsifiers.
• Nullifying rust-inhibitors.
• Cuts off air and thereby provides an excellent base for
growth of anaerobic bacteria.
• Reduce amount of sulfur additives.
• Drop in pH.
• Create bad smell.
• Low pH increases ionization of heavy metal in coolant
and this in turn may create unhealthy working
atmosphere.

36. EMULSIONMANAGEMENT
Saponification value is expressed by potassium hydroxide in mg
required to saponify one (1) gram of fat. By measuring
saponification value, mean molecular mass can be obtained.
Saponification value is inversely related to mean molecular mass.
It is a measure of the average molecular weight (or chain length)
of all the fatty acids present. As most of the mass of a fat/tri-ester
is in the 3 fatty acids.
Analysis of Used Extracted oil:
SAP Value –
• Lowered with contamination of Tramp Oil.
• % drop indicates reduction of the active oil in
emulsion.
• Should not fall below 70%.
IR Spectroscopy –
• Predicts Ester content & Fatty Acid concentration.
• Identify contamination.

37. Rolling Oil Solution Management
ROLLING OIL MAINTENANCE
&
MANAGEMENT

38. Rolling Oil Emulsion Management
Scum & Tramp Oil Removal:
Action Plan to reduce Tramp Oil when it exceeds
the limit of 12%:
 Overflow the coolant in Agitator running condition to
remove the scum & tramp oil – As per schedule.
 Ensure continuous and effective running of scum
pusher.
Benefit:
 Less oil loss.
 Saponification value (SAP) is maintained within the
required range (160 Mg KOH / Gm Min).
 Good lubricity at roll bite.
 Surface cleanliness.

39. Rolling Oil Solution Management
Emulsion Temperature:
Action Plan to maintain temperature range 50 – 60 Deg :
 Avoid direct steam heating to minimize of oxidation of oil &
contamination in coolant.
 Maintain coolant temperature in the tank at 55-60 Deg C to get the
coolant temperature at roll bite as 50-58 Deg C.
 Ensure the regular functioning of temperature controller using
Thermostat control valve.
Benefit:
 Coolant temperature at 55 Deg C at roll bite Provides
- Optimum lubricity
- Reduce power cost &
- less surface defect.

40. Rolling Oil Solution Management
Oil Addition:
Action Plan to maintain Oil % in range of 3 – 4%
 Oil addition on daily basis.
 Start with the rate of 0.3 kg/Ton, calculation based on actual
daily production.
 Optimize the specific consumption in between 0.25-0.30
kg/Ton.
 After bottom draining & overflow of coolant, check the oil
concentration first in running condition and adjust the
concentration with required quantity of oil addition.

41. Rolling Oil Solution Management
Conductivity Control:
Conductivity is the concentration of ions in the water / emulsion.
These ions are dissolved salts and Inorganic materials like alkalis,
chlorides etc.
Action Plan to reduce Conductivity below 400 μS/cm level:
 Stop Agitators and coolant circulation pump.
 Wait for half to one hour so that most of the active oil gets accumulated at
the top and chloride ions & others settled down at the bottom of the tank.
 Start bottom draining of coolant (approx. 10% of total volume) from COT &
DOT .
 After bottom draining of coolant, check the oil concentration first in
running condition then adjust the concentration with required quantity of
oil addition.

42. Rolling Oil Solution Management
Chloride Control:
Action Plan to reduce Chloride level below 100
ppm:
 Same action plan of Conductivity control to be followed
to reduce Chloride level .
 After bottom draining maintained the emulsion level
with Fresh RO water addition & oil addition if required.

43. Rolling Oil Solution Management
Agitator in Coolant Tank:
Recommendation:
 All the agitators must be in running condition all the
time to avoid oil floatation at the top and to maintain
consistent coolant parameters.
Benefit:
 Consistent oil concentration & uniform lubricity during
rolling.
 Less oil loss – Reduce oil consumption & oil cost.

44. Rolling Oil Solution Management
Coolant Flow :
Recommendation:
 Maintain maximum uniform coolant flow & pressure in 6 Hi Mill as per
mill design. In BPSL Kolkata, 5000 lpm is maintained for 1000 mm wide
6Hi Rolling Mill and 6000 lpm for 1250 mm wide 6Hi Rolling Mill.
 Coolant pressure at roll bite is maintained 5kg/cm2
Benefit:
 Consistent lubricity
 Uniform cooling of roll & sheet during rolling.
 Optimum Roll Force.

45. Rolling Oil Solution Management
Iron Content:
Action Plan to reduce the Iron level below 150 mg/ltr:
 Optimize the schedule for running magnetic Separator to maintain the
iron level in solution. For example: 30 min. after every four hours of
rolling.
 To ensure low force rolling.
Emulsion cleanliness:
1. Ensure smooth & regular running of self cleaning filter/backwash filter.
2. Ensure cleaning of bucket filters on weekly basis.
3. Ensure regular running of magnetic separator.

46. Rolling Oil Solution Management
Pickled coil contamination control:
Action Plan:
 Control checks of pH & Chloride of Pickle Line final rinse water to
eliminate acid carry over & chloride contamination – Random checks.
 Ensure pH level minimum 6.5 and Chloride content maximum 10 - 15
ppm in final Rinse tank.
 Observe surface quality of pickled coils before cold rolling.
Benefit:
 Eliminate the possibility of pH drop & chloride contamination in rolling
oil solution.

47. Rolling Oil Solution Management
STATISTICAL ANALYSIS

48. STATISTICAL ANALYSIS
DATE
CONDUCTIV
ITY
1-Sep 358
2-Sep 359
3-Sep 365
4-Sep 370
5-Sep 369
6-Sep 388
7-Sep 410
8-Sep 338
9-Sep 338
10-Sep 356
11-Sep 355
12-Sep 372
13-Sep 364
14-Sep 390
15-Sep 370
200
250
300
350
400
450
500
CONDUCTIVITY
DATE
CONDUCTIVITY (μS/CM)

49. STATISTICAL ANALYSIS
DATE PH VALUE
1-Sep 6.31
2-Sep 6.31
3-Sep 6.28
4-Sep 6.35
5-Sep 6.34
6-Sep 6.34
7-Sep 6.39
8-Sep 6.4
9-Sep 6.4
10-Sep 6.38
11-Sep 6.42
12-Sep 6.42
13-Sep 6.43
14-Sep 6.41
15-Sep 6.38
5.8
5.9
6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
PHVALUE
DATE
PH VALUE

50. STATISTICAL ANALYSIS
DATE ESI VALUE
1-Sep 0.66
2-Sep 0.66
3-Sep 0.66
4-Sep 0.66
5-Sep 0.67
6-Sep 0.68
7-Sep 0.7
8-Sep 0.7
9-Sep 0.67
10-Sep 0.68
11-Sep 0.65
12-Sep 0.65
13-Sep 0.66
14-Sep 0.66
15-Sep 0.63
0.28
0.38
0.48
0.58
0.68
0.78
0.88
ESI
DATE
ESI VALUE

51. STATISTICAL ANALYSIS
DATE TRAMP %
1-Sep 9.0
7-Sep 8.70
13-Sep 9.64
19-Sep 11
25-Sep 10
1-Oct 11.25
7-Oct 12.3
13-Oct 10
19-Oct 9
25-Oct 10.76
31-Oct 9.66
6-Nov 9.61
12-Nov 8.46
18-Nov 10
24-Nov 9.09
0
2
4
6
8
10
12
14
16
18
20
01/Sep 08/Sep 15/Sep 22/Sep 29/Sep 06/Oct 13/Oct 20/Oct 27/Oct 03/Nov 10/Nov
TRAMP%
DATE
TRAMP %

52. STATISTICAL ANALYSIS
DATE
SAPONIFICATI
ON VALUE
1-Sep 183
7-Sep 184
13-Sep 182
19-Sep 181
25-Sep 184
1-Oct 183
7-Oct 185
13-Oct 182
19-Oct 183
25-Oct 180
31-Oct 182
6-Nov 183
12-Nov 184
140
150
160
170
180
190
200
210
220
1-Sep 2-Sep 3-Sep 4-Sep 5-Sep 6-Sep 7-Sep 8-Sep 9-Sep 10-Sep 11-Sep 12-Sep 13-Sep
SAPONIFICATIONVALUE
DATE
SAPONIFICATION VALUE (mgKOH/GM)

53. STATISTICAL ANALYSIS
DATE
TEMPERAT
URE
1-Sep 60
2-Sep 59
3-Sep 53
4-Sep 50
5-Sep 54
6-Sep 55
7-Sep 58
8-Sep 50
9-Sep 55
10-Sep 54
11-Sep 61
12-Sep 54
13-Sep 55
14-Sep 54
15-Sep 59
20
30
40
50
60
70
80
TEMPERATURE
DATE
TEMPERATURE (°C)