1. Influence of process on quality
And quality control on process

2. Why we maintain quality ?
It is need of the customer
Customer is the king .He sees us in quality price ratio
To day mason decides the quality but tomorrow engineer
will decide the quality in our country ( house construction
, etc)
What will happen to us ?

3. Customer is the king. He is a better business man than you.
Tomorrow’s market is competitive with quality/ price ratio.
Customer creates the customers.
Bon’t brand the quality alone , brand your service too.

4. Mining
crushing
preblending
Raw meal
preparation
Raw meal
blending
Pyro
process
Clinkercooling
Cement
grinding
Packing &
despatch
Process steps
Concern
for Environm
ent
Q
uality
control

5. Process flow diagram and integration of quality
Quality control

6. Variation makes the process and quality to struggle and custome
unhappy
customer

7. Mining
Well developed mines

8. Geology and location of boreholes
Bore
Hole
sample

11. Function of PGNA
Analyser
Cf 252

13. Variation is a devil
In any process

16. Lime saturation factor on clinker basis
If MgO is below 2 %
LSF = 100( CaO – free CaO+0.75 MgO)
(2.85 SiO2) + ( 1.18 Al2O3) +(0.65 Fe2O3)
If MgO is above 2 %
LSF = 100( CaO – free CaO+1.5 MgO)
(2.85 SiO2) + ( 1.18 Al2O3) +(0.65 Fe2O3)
95 – harder to burn, tendency to high free lime & C3S clinker
, high early strength high fuel consumption
< 95 , easy to burn , excess coating , excess liquid phase ,
possible brick infiltration reduced cement strength , low free lime
acceptable standard deviation = 1.2

19. Raw meal residue
Depends upon the
Mineralogy , ie
Calcite or quartz
90 mic = 8 – 15 %
212 mic = 0.5 – 3 %

21. time
Variation from
mines
Variation
After
pre blending
Variation after
Raw milling
Variation in quality control
Set point

26. Auto sampler position
- 20 mm

30. Liter weight

36. . Rapid burning ( short burning zone ) and rapid cooling of clinker
improves the clinker quality. smaller C3S crystals with
micro cracks)

37. Slow burning
Fast burning

39. C3S
Clinker when it is quenched in cooler it creates micro cracks which
needs less energy for comminution during grinding.
C3S
Clinker cooling
C2S

40. Reactions during clinker cooling
Resorption of alite
Liquid phase + C3S C2S + C3A + C2(A,F)
Decomposition of alite
very slow cooling
reducing conditions
C3S C2S + CaO
Crystallization of liquid phase
Slow cooling: large crystals – improved reactivity
MgO crystals grow on
cooling (periclase)

56. Properties of cement

58. • Portland cement
• Portland pozzolana cement
• Portland slag cement
• Sulfate resistant cement
• Oil well cement
• Rapid hardening cement
• White cement

59. Cement quality tests
• Setting time
• Compressive strength (mortar)
• Modulus of rupture ( bending strength)
• Fineness( blaine or Particle size distribution)
• Expansion ( Le Chatelier & Auto clave)
( soundness)
• Chemical analysis

60. X-4.0(100-
X) /100 <
35%
3.03.03.0Insoluble residue % (max)
0.8 -
1.02
0.8 -
1.02
0.66 -
1.02
LSF CaO- 0.7 SO3/(2.8S+1.2A+0.65F)
PPC53S53 Gr43 Gr
specifications
5.04.04.05.0LOI
3.03.03.03.0SO3 % max
6.05.06.06.0Magnesia ,MgO %,max
0.050.100.10Cl max
> 45C3S
10.0----C3A max
BIS specifications for various grades of cement

61. 1051010.0Soundness ,LeChat expansion , (mm) max
30/60060/60030/60030/600Setting time, initial ( min) / final (max) ,
minutes
300.0370.0225.0225.0Fineness sqm /kg , min
162727233 days+/_ 1 hr
Compressive strength, Mpa , min
0.80.80.80.8Soundness, Autoclave %
0.15Drying shrinkage
3353534328 days +/ - 4 hrs
2237.533337 Days +/_ 2 hrs

62. Blaine apparatus air
permeability test

66. (Part - 5) Determination of Initial and Final Setting
Times4031 (Part-5)
Early stiffening – false set or flash set
If less gypsum no gypsum flash set occurs
If cement temperature > 130 deg c gypsum dehydrates and flash set occurs

67. Setting time ASTM specification

68. In concrete chemistry ettringite is a hexacalcium aluminate trisulfate hydrate, of
general formula: (CaO)6(Al2O3)(SO3)3·32H2O or; CaO)3(Al2O3)(CaSO4)3·32H2O

69. Influencing parameters on
Cement strength

70. 1 3 7 28 90 days
Strength MPa
C3S
C2S
C3A
C4AF
60
0
20
30
40
50

71. = f (C3S)
28
7
3
1
MPa 70
60
50
40
30
20
10
40 45 50 55 60 65 % C3S

72. = f (Wk)
28
7
3
1
0
MPa 70
60
50
40
30
20
10
0 0.5 1.0 % Wk
A 1% increase in LOI
result in decrease in
strength
1 day by 25 %
2 8days by 3 % and
90 days by 2 %

73. Cement strength is measured in 1 day, 3 days ,7days and 28 days
Measurement compressive strength BIS 4031 (Part-8)1988(Part - 8)
Determination of Compressive strength of hydraulic Cement

75. Compression testing
50*50mm

76. Compressive strength – influencing parameters
Compressive strength
1 d 3 d 7 d 28 d
Influencing Normal range 5 – 15 20 – 35 30 - 45 45 - 60
Parameters OPC
C3S 45 – 65 % + + + +
C3A 6 – 12 % + + + +
Ks 0.2 – 1.5 % + + +/0/- -
SO3 2 – 4 % +/0/- +/0/- +/0/- +/0/-
Blaine 280 – 300 + + + +
m2/kg
Wk 0 - 0.3% - - - -

77. Quantitative rules of thumb
C3S : 1 – 28 d : + 0.5 Mpa / %
Ks ; 1 d : + 4 Mpa / %
: 3 d : + 4 Mpa / %
: 7 d : - 2 Mpa / %
: 28 d : - 10 Mpa / %
(SO3) tot : 1 - 28 d : - 5 Mpa / % from
optimum
Blaine : 1 d : + 0.04 Mpa / (m2/ kg)
3- 28 d : + 0.08 Mpa / (m2/ kg)

78. One day strength is contributed mainly by
C3A , Soluble alkalies, and C3S
3 day is contributed mainly by C3S
7 days strength is contributed by mainly
C3S
28 days strength is mainly contributed by
C2S
Apart from the above cement strength is enhanced by
higher fineness of cement
Less C3S crystal size achieved by rapid burning
and quenching the clinker in cooler
Higher fineness of rawmeal also reduces the
crystal size of clinker minerals , ie ., C3S & C2S which
enhances the hydraulic reactivity
Cement strength – influencing parameters

79. Wk , prehydration of clinker
Prehydration of clinker minerals can occur
1. As a result of incorrect internal water cooling in cement mill
2. when storing too hot cement in a silo
3. When clinker and especially cement is exposed to humidity
Please note:
If clinker has more soluble alkalis and sulfates it is highly
hygroscopic especially when pet coke is fired.
In cement silos they form Syngenite , K2SO4.2 CaSO4. H2O which
forms lumps and block the cement silos. Hence venting is must
to evacuate moisture and silo cleaning.
cements having soluble alkalis and sulfates preferably packed in
paper bags to avoid depletion of strength.

80. Thumb rule formulae for prediction of strength
FLS predicted the formula for cement ground to 300 kgs/ m2
With 4 % gypsum
strength,
d28 = 52 - 10.( Ks) + 0.15.(C3S)
The content of soluble alkalis Ks is dependent on the total alkali
content and SO3 content in clinker.
As per Knofel it is
F 28 = (3*C3S)+ (2*C2S) + C3A – C4AF N / mm2
Strength prediction
for 3 d = 97 + 35.8 Ma + 38.1K2SO4 + 28.7 Ms – 1.3 C3S Kg/ cm2
7 d = 300 + 13.4 Ms + 2.8 C2S + 56.1 Ma – 15.4 K2SO4 + 15.5 Na2O
28 d = 490 – 55.3 K2SO4 + 1.3 C3S (or)
= 490 – 86 K2O + 2 C3S – 26 Na2O

81. Influence of fineness on cement strength
For cements with the same specific surface the increase of the uniformity
factor results in increase of strength of all ages.
1. The specific surface , the percentage of fractions 3- 32 mm and the
uniformity factor n really influences the development of cement strength.
The influence of 3 - 32 mm fraction and the uniformity factor is higher in
cement with higher in specific surface ( > 3400 cm2/ g)
2. The fractions with particle size less than 3 mm contributes only to early
strength while the fraction with particle size more than 24 mm influences
strength development significantly.
3. While the fractions 3 – 16 mm and 16 – 32 mm seems to be more
significant factor for specific surface 3500 – 4000 cm2/ g) . This is
relevant only if the granulometric distribution is continuous and steep.
4. The optimistic granulometric distribution of a cement is a continuous
and steep ( with high uniformity factor) distribution with a high (65 %)
content in 3 – 32 mm fraction and specifically in 16 - 24 mm fraction and
low content of fine particles ( < 3 mm , 10 % ) and specific surface of
2500 – 3000 cm2/ g according to Blaine.( high efficiency separator and
grinding media distribution plays significantly here)

82. Properties of cement minerals
Characteristics C3S C2S C3A C4AF
Setting quick slow rapid nil
Hydration rapid slow rapid nil
3 days heat 1.1 cal / g 0.4 cal / g 2 cal / g nil
liberation
Early strength high upto low upto not much nil
Contribution 14 days 14 days beyond one day
Late strength less later high later nil nil
contribution
Resistance to moderate high poor high
Chemical attack
Drying shrinkage nil low nil nil

83. Measurement of expansion for free lime ( IS 4031 Part3 -1988
Expansion due to free CaO=< 10 mm

84. Auto clave test for
expansion of cement
(Part - 3)
Determination of
Soundness
198
8
4031
(Part-3)
25*25*282mm
Expansion limit < 0.8mm

85. Autoclave
Calorie
meter

87. Tube samplers for bulk cement

88. MgO Crystals
Or Periclase

90. Free lime clusters

92. Problems and solutions
1. Grinding problems
a) False set lower cement mill temperature
add less gypsum
add part anhydrite
b) reduced strength high mill temperature
less water cooling
correct water cooling
2. Silo storage
a) False set short storage time
cooling of cement < 70 deg c
b) reduced strength increase gypsum dehydration in
mill
c) lump formation and add less gypsum, use partly
silo blockage (syngenite anhydrate , decrease K2O content
formation, K2SO4.2CaSO4.H2O to avoid the formation of Syngenite
Problems solutions

93. 3 ) Bag storage
a. reduced strength short storage time
b. lump formation add TEA during grinding
(tri ethanal amine)
add hydrophobic agents
c. crust formation plastic coated bags
d. abnormal setting plastic covering pallets

94. quality
Process
Quality is a set point and process is variable
Right

95. Process
quality
Process is a set point and quality is variable
wrong

96. Thanks you for your kind attention
And spending your valuable business hours
K.P.PRADEEP KUMAR
Sr.GM Operation
Karikkali works
Chettinad Cements Ltd