Kerphalite™ KF for Cores Kersand™100-400 for Mould
SPECIAL SAND FOR FOUNDRY Ankiros 2018
What is Kerphalite™KF & Kersand™100-400 ?
Philippe Diaz 2
Kerphalite™ KF & Kersand™100-400 are both “andalusite” mineral.
Kerphalite™ KF & Kersand™ 100-400 are an alternative to traditional natural sands such as silica sand and , chromite or zircon for cores and molds production.
Key properties are:
High Refractoriness (capability to withstand high temperature without melting or softening)
Low Thermal Expansion
High Thermal Conductibility
Suitable for all organic binders
Total compatibility with Silica Sand
Kerphalite™KF & Kersand™100-400 – Production
Philippe Diaz 3
Kerphalite™KF & Kersand™100-400 requires many processing stages to achieve the quality required by the foundry application
Mining and Processing plant is located in France
18 years of extraction rigth
Kerphalite™KF & Kersand™100-400 – Chemistry
Philippe Diaz 4
Both are pure aluminosilicate : Al2O3·SiO2
Typical Chemical composition :
Typical Chemical comparison :
Kerphalite™
KF
Kersand™
100-400
Al2O3 61% 59%
SiO2 38% 39%
Fe2O3 0,5% 0,75%
K2O + Na2O + MgO + CaO < 0,5% < 1%
% Al2 O3 SiO2 MgO CaO Fe2O3 K2O TiO2 ZrO2 Na2O Cr2 O3
Kerphalite™ KF 60,8 38,1 0 0 0,45 0,1 0,1 0 0,1 0
Kersand™ 100-400 59,1 38,5 0,15 0,1 0,75 0,3 0,25 0 0,15
Zircon Sand 0,8 32 0 0 0,1 0 0,2 63,5 0 0
Chromite Sand 14,8 0,9 9 0 30,4 0 0,5 0 0 43,6
Ceramic Beads 60% 60,1 36,9 0 0,2 1,2 0,1 0,5 0,1 0,5 0
Kerphalite™KF & Kersand™100-400 – Refractoriness
Philippe Diaz 5
Due to the high alumina content (> 60%) and low alkalis level vs ceramic beads 60%
Melting point of Kerphalite® KF exceeds 1800°C
Kerphalite™KF & Kersand™100-400 – No risk of Fayalite defect
Philippe Diaz 6
Fe2O3 content in chromite blended with silica sand can provide a tremendous drop of the melting point.
Sintering phase occur at 1208°C
These is fayalite
Kerphalite™KF & Kersand™100-400 – Chromite + Sand defects
Philippe Diaz 7
Chromite is mainly recommended when an effective magnetic separation system available.
If not, following sand penetration could occurred.
0
10
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30
40
50
60
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% o
f co
re v
olu
me
aff
ect
ed
by
me
tal p
en
etr
ati
on
Amount of Chromite
Impact of Chromite on Metal Penetration of Silica sand core Gertsman Test - Carbon steel E20-40M
Poyet, P; Chevriot, R - 46th international Foundry Congress - Madrid 1979
Kerphalite™KF & Kersand™100-400 – Thermal Expansion
Philippe Diaz 8
Thermal expansion is the key point to reduce veining defects
Both shows a low thermal expansion rate, close to zircon and significantly lower than silica sand, olivine & chromite
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
1,8
0 200 400 600 800 1000 1200 1400
dl/
L
Temperature °C
Quartz
Olivine
Chromite
Zircon
Kerphalite &Kersand
Kerphalite™KF & Kersand™100-400 – Cooling Effect
Philippe Diaz 9
We have introduced relevant parameter in Software Magma5
We have designed a simple but massive casting roller (40cm diam) with central core (4cm diam).
The simulated curves have been taken from the center of core.
Results
Cooling behavior of Kersand is performing as chromite
Other sands like Treibacher Alodur ® WRG performe far better than chromite !!
Kerphalite™KF & Kersand™100-400 – Thermal Resistence test 1/2
Philippe Diaz 10
Thermal resistance test allows to simulate thermal radiations & convections
during pouring time
Moving
support
1500°C
Sand Sample
Furanic binder
1500°C Thickness: 5mm
Final temperature is reached in about 2 minutes
1000
1100
1200
1300
1400
1500
1600
0 20 40 60 80 100 120 140 160 180 200 220 240t [s]
T [
°C
]
Kerphalite™KF & Kersand™100-400 – Thermal Resistence test 2/2
Philippe Diaz 11
Kerphalite™ KF & Kersand™100-400 doesn’t show any melted phases at 1500°C
The blend with 50% of silica sand increases the melting phase but allows significant improvement vs pure silica
100%
Kerphalite & Kersand
100%
Silica Sand
Mel
ted
Ph
ase
%
Melted Phase after Thermal Shock 2 to 20 min 1500°C - Furanic Resin
0
5
10
15
20
25
0 10 20 30 40 50 60 70 80 90 100
% Kerphalite KF
2 min
5 min
10 min
20 min
Kerphalite™KF & Kersand™100-400 – Heating Microscope
Philippe Diaz 12
Heating microscope chart below shown us, at 3 different % of shrinkage, the temperature of softening.
Kersand™ 100-400 as Kerphalite™KF perform well and much better than mullite beads e.g.
Kerphalite™KF & Kersand™100-400 – Reclaimed level & LOI
Philippe Diaz 13
Courtesy of Omega
Yield recovery between 77% and 82% of Kerphalite KF recovered.
0,0000
0,5000
1,0000
1,5000
2,0000
2,5000
KF 100-400As received
KF100-400Before USR
KF100-400After 1stPass USR
1st PassUSR
re-check
LOI
LOI
LOI
Kerphalite™KF & Kersand™100-400 – Reclaimed PSD and Sphericity
Philippe Diaz 14
Courtesy of Omega
0
5
10
15
20
25
30
35
40
45
1000 710 500 355 250 180 125 90 63 Dustpan
Kerphalite KF 100-400 as received -AFS 64
Kerphalite KF 100-400 after 1 passUSR - AFS 71
Kerphalite™KF & Kersand™100-400 – Bending Strength
Philippe Diaz 15
Bending Strength in Mpa on various materials.
In the same lab conditions.
furane
Sodium
Silicate
CO2
Phenolic
Alkalin
Phenolic
Urethane
Self Set
Material* 24 hours 24 hours 24 hours 24 hoursAs
Gassed24 hours Hot Cold
European Silica Sand 4,5 2,2 1,9 3,6 4,3 5,2 6,4 8,8
Kerphalite KF 100-400 3,8 2 1,8 3,2 3,3 3,8 4,5 5,6
Kersand 100-400 3,5 2 1,7 3 3,2 4,1 5,5
ImerBeads 45AFS 4,6 2,3 2 3,5 4,9 6,2 6,7 9,2
Clayrac F45 100-400 3 1,9 4 5
* Blended with 50% silica sand
Phenolic Urethane
Cold Box
Pre Coated Sand in
Mpa
Kerphalite™KF & Kersand™100-400 – Differents Grades
Philippe Diaz 16
AFS 50
0
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30
40
50
60
70
425µ 300µ 212µ 150µ 106µ 75µ 53µ
AFS 60
0
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10
15
20
25
30
35
40
45
425µ 300µ 212µ 150µ 106µ 75µ 53µ
AFS 70
0
5
10
15
20
25
30
35
40
425µ 300µ 212µ 150µ 106µ 75µ 53µ
AFS 100
0
10
20
30
40
50
60
425µ 300µ 212µ 150µ 106µ 75µ 53µ
All usual AFS grades are available and possibly designed for special needs.
Both have the same bulk density close to silica sand.
You can produce 40% more cores, using Kerphalite or Kersand vs chromite or zircon
20 tons
Kerphalite™KF & Kersand™100-400 – Bulk density 1/2
Philippe Diaz 17
Kerphalite KF
12,5 m3
Kersand™
7,4 m3
Zircon
Based on previous slide, we take an example of foundry which is buying 300tons/ year of chromite
The Volume of chromite bought is 111m3
For same volume, that’s means, same quantity of core & mold , you ONLY need to purchase 178 tons per year instead of 300Tons of chromite
Resin consumption is also a sensitive topic
As all resin setting are based on sand , we weight resin/catalyst & sand at the screw of mixer
So, we should calculate on weight = Tons/year.
Even using 40% more resin with KERPHALITE !!
Foundry Manager introduce less resin in his sand reclamation => Less gas to remove during pouring
Purchasing manager will save 17% on total binder cost.
Kerphalite™KF & Kersand™100-400 – Bulk density 2/2
Philippe Diaz 18
Type of Sands DensityQuantity of Sand needed
in Tons per year
Equivalent in
Volume in m3
Savings
in tons
CHROMITE 2,7 300 111,1 0
KERPHALITE KF 1,6 177,8 111,1 122
Sands % of resinResin needed
per Year (en Kg)Savings
CHROMITE 1,00% 3000 0
KERPHALITE KF 1,40% 2489 -17%
Kerphalite™KF & Kersand™100-400 – Summaries
Philippe Diaz 19
Kerphalite™ KF & Kersand™ 100-400 will respond to special core shop as
molding requirements :
Low Thermal Expansion High anti veining properties
Good Thermal diffusivity and Conductivity Relative good Chilling effect.
Very low level of Fe2O No risk of fayalite Defect, no sand penetration
High refractoriness - 58 - 60% alumina
PSD properly design for all type of core application
Acceptable sand reclamation level.
Low density 40% more cores produced
Aluminosilicate mining and processing in Europe.
Thanks for your attention
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