Metacal-metakaolin through flash calcination-2 different types

1. CAL
METAKAOLIN

3. Introduc2on
Al2O(SiO2)2
(H2O)x+
(2-­‐x)H2O
(metakaolin)
grinding
/
pelle:zing
rotary
kiln
calcina:on
(5h
750°C)
+
ground
KAOLINITE (kaolin)
aluminium
silicate
Al2O3
(SiO2)2
(H2O)2
METAKAOLIN
finely
ground
+
flash
calcina:on
method
(few
seconds
750°C)

4. two
types
off
white
pink
colored
white
colored
rotary
kiln
calcina:on
round
shaped
plate
structure
flash
calcina:on
CAL

5. Through
FLASH
CALCINATION
metakaoline
turns
to
round
beats
,
whereas
a
plate
structure
is
obtained
in
tradi:onal
produc:on
1
μm
0,5
μm
0,5
μm
0,5
μm
Kaolin
Metakaolin
Flash
calcina2on
Rotary
kiln

6. Al203
40~45
%
SiO2
30~55
%
Blaine
>
12,000
gm2/g
Average
par:cle
size
1
μm
Density
2,6
Shape
plate
to
round
structure
average
composi2on

7. According
to
the
La
Chapelle
test
both
types
have
the
same
lime
binding
factor
~1300
gr
of
lime
per
100
gr
of
metakaolin
Chapelle
test
Comparision
of
puzzolanic
reac:vity
(Chapelle)
Materials
Puzzolanic
reac:vity
mgCa(OH)2/g
blast
furnace
slag
40
eco-­‐binder
306
silica
fume
427
calcined
bauxite
534
fly
ash
875
CAL 1205

8. Al2O3·∙(Si2O2)2+CH+H
METAKAOLIN
calcined
at
proper
temperature
brings
a
highly
reac:ve
pozzolanic
material
which
reacts
with
calcium
hydroxide
(CH)
higher
temperature
leads
to
recrystalliza:on
and
reduc:on
of
reac:vity
and
converts
to
an
inert
filler
CSH
+
C4AH13
and
C3AH6
(hydrated
calcium
aluminates
)
+C2ASH8=
gehlenite
hydrate
or
stratlingite
(incorpora:on
alkali)

9. METAKAOLIN
will
accelerate
the
se`ng
of
cement.
As
it
reacts
with
the
lime
released
during
hydra:on
of
Portlandcement
,
the
C3A
content
will
go
in
solu:on
quicker.
It
reduces
the
pH
whereby
the
stratlingite
(C2ASH8)
will
incorporate
hydroxide
and
chloride
ions
in
its
structure
In
:me
more
portlandite
is
formed
leading
to
higher
strengths
and
durability.
It
is
about
10
:mes
finer
than
Portlandcement
giving
the
matrix
beder
compac:on
fewer
pores
and
smaller
pore
size.

10. prevents
fading
of
colours

11. prevents
lime
bloom

12. reduc:on
of
cracks
and
voids

13. improved
impermeabilty
–
reduced
risk
of
ASR
and

14. resistant
to
sulfate
adack
and
(de-­‐icing)
salts
preven:on
of
spalding

15. No
CO2
produc:on
according
to
the
chemical
reac:on
Low
temperature
of
the
process
750
°C
Consump:on
of
energy
2900
MJ/tonne
CO2
produc:on
150
kg/tonne
environment

16. • increased
cost
price
• higher
water
ra:o
• workability
• addi:onal
raw
material
• at
low
addi:on
rate
increase
shrinkage
dis
advantages

17. Mortars,GRC
and
concrete
manufactured
with
Metakaolin
will
exhibit
the
following
benefits;
ü increased
compressive
and
flexural
strength
ü improved
durability
ü reduced
permeability
ü reduced
efflorescence
ü increased
chemical
resistance
ü reduced
chloride
migra:on
ü increased
viscosity
ü enhanced
workability
and
finishing
ü reduced
effects
of
alkali-­‐silica
reac:vity
(ASR)
ü increased
adhesion
ü reduced
shrinking
ü lighter
color
ü reduc:on
of
CO2
advantages

18.
ü reduced
alkali
–
GRC
applica:on
–
protec:on
of
AR
glass
ü forma:on
of
secondary
C-­‐S-­‐H
ü elevated
elas:c
modulus
(EMR)
ü less
pores
ü smaller
pore
size
ü improved
early
and
late
strength
cement
and
lime
ü consistent
color
ü color
sustainability
ü low
risk
on
lime
-­‐
bloom
ü produc:on
of
hydraulic
lime
through
blending
ü geo-­‐polymers
ü It
improves
the
density
of
the
cement
matrix
through
its
fineness
and
the
reac:on
with
CH
See
more
at:
www.caltra.com
further
advantages