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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
02. Refractory
Pyrometallurgy (MG3111)
5th Semester – 2021/2022
Zulfiadi Zulhan
Taufiq Hidayat
Imam Santoso
Department of Metallurgical Engineering
Faculty of Mining and Petroleum Engineering
Bandung Institute of Technology
INDONESIA
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
NO TALKING
NO SLEEPING
NO MOBILE PHONE
http://www.longestlife.com
https://www.pinterest.com
https://www.pinterest.se
http://clipart-library.com
https://www.dreamstime.com
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Course Content
1. Introduction
2. Refractory
3. Slag
4. Drying, Calcination, Roasting
5. Carbo- / Aluminothermic (Metalothermic)
6. Smelting, Refining
7. Pyrometallurgy of Copper I
8. Pyrometallurgy of Copper II
9. Mid Exam
10. Pyrometallurgy of Tin
11. Pyrometallurgy of Nickel (Nickel Matte, FeNi)
12. Pyrometallurgy of Zinc and Lead
13. Ferro Alloy I (FeMn)
14. Ferro Alloy II (FeCr, FeSi)
15. Group Presentation (FeNb, FeMo, FeTi, FeV, FeTa, FeW, CaSi, CaC2 etc.)
16. Final Exam
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
http://www.thorpessc.com/what-makes-us-different/the-three-keys-to-reliability/
http://www.lkabminerals.com/
http://ricc.ir/?page_id=1205
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
http://tridentrefractory.com/testimonials/hulamin-
refractory-reline-works-on-line-2-remelt-furnace/
http://www.refraline.com/refraline-0?page=3
http://www.steuler.de/en/steuler-kch/refractory-systems/refractory-
linings/cement-paper-and-cellulose-industry/
http://www.tjskl.org.cn/images/czae7149-pz247b738-
rotary_kiln.html
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Flash Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Isasmelt and Ausmelt
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Reverberatory Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Mitsubishi Process
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Mitsubishi Process
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Imperial Smelting Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Teniente / Noranda
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Peirce Smith Converter
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Anode Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Bubbling
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Bubbling
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
• Refractory are the primary materials used in the internal lining of
furnaces.
• Able to withstand temperatures from 600°C – 2000°C
mechanic
Refractory
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory and industrial materials melting point
chart
231327
419
660
1082
1455 1538
0
500
1000
1500
2000
2500
3000
3500
4000
4500
TinLe
adZin
c
Alum
inium
Cop
per
Nicke
l Iro
n
Refra
ctoy
Key Industrial Materials
Melt
ing
Po
int
(°C
)
Graphite, C, pure 3482
Thoria, ThO2, pure sintered 2998
Magnesia, MgO, pure sintered 2798
Zirconia, ZrO2, pure sintered 2698
Beryllia, BeO, pure sintered 2548
Silicon Carbide, SiC pure 2248
Magnesia, 90-95% 2193
Chromite, FeO-Cr2O3 2182
Chromium Oxide 2137
Alumina, Al2O3, pure sintered 2048
Chromite, 38% Cr2O3 1971
Alumina, fused bauxite 1871
Silicon Carbide 1871
Fire clay 1871
Kaolin, Al2O3-SiO2 1815
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory is expensive
• Means: any failure in the refractories results in a great loss of production
time, equipment, and sometimes the product itself.
• Type of refractories will influence energy
consumption and product quality.
http://www.mintek.co.za/Pyromet/200kVA.htm
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory Forms
Refractories are produced in two basic forms:
bricks / shapes bricks / shapes
1. Preshaped / preformed objects: bricks / shapes
2. Unformed products (specialties / monolithics): castables, pourables,
spray mixes, gunning mixes.
MSTS, AISE, 1998
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Monolithics
Castables, or refractory concretes, are predominately dry, granular refractory
mixes designed to be mixed on site with water and capable of curing to a
stable dimensional form. Castables are particularly suited to the molding of
special shapes and parts at the installation site. They can be used for forming
complete furnace linings, and other unique shapes.
Gunning mixes comprise a variety of specialty refractory compositions that
develop a solid shape by air drying or heat curing. The principal requirements
are that they can be blown into position by air pressure through a lance or
nozzle, but must adhere on impact and build up to the desired lining
thickness. They are used for repairs, especially inside empty, hot furnaces.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Gunning Mix
Alumina for Gunning Mix
Magnesia for Gunning Mix
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
LD Converter (repair zones)
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Monolithic: Anchor
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Three classes of refractory (base on chemical
composition)
• Acid (SiO2)
should not be used in contact with basic slags, gases or fumes
• Basic (CaO, MgO)
used with basic chemical environment
• Neutral (Al2O3, Cr2O3)
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Base Material for Refractory
Chemical Name Abbreviation Chemical Formula Melting Point, °C
Magnesium Oxide M MgO 2825
Aluminium Oxide A Al2O3 2050
Graphite - C > 3500
Silicon Oxide S SiO2 1610
Calcium Oxide C CaO 2614
Chromium Oxide - Cr2O3 2266
Zirconium Oxide - ZrO2 2715
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia
1. MgO : chemical formula for
pure magnesium oxide
2. Magnesia : chemical name applied to
the oxide of magnesium
3. Periclase : mineral name for magnesium oxide (this mineral is
rarely found in nature; dead burned magnesium oxide
products, contained less than 10% impurities).
4. Magnesite : mineral name for magnesium carbonate, MgCO3, and
was one of the original sources for magnesium oxide
used in refractory products.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Definition
Magnesia refractory is defined by ASTM as a dead-burned refractory
material consisting primarily of crystalline magnesium oxide.
Dead burned: state of a basic refractory material resulting from heat
treatment that yields a product resistant to atmospheric hydration or
recombination with carbon dioxide.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Heat Treatment
• Calcined : heat treatment is mild (~ 900 – 1300°C).
• Sintered : heat treatment in the range of ~1500 – 2200°C
(dead burned materials are in this group)
• Fused : temperature > 2800°C
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesium Oxide
Magnesium oxide has a very high melting point (about 2800°C).
Limitation: high thermal expansion
and high thermal conductivity
High melting point, resistance to basic slag, moderate cost, make
magnesium oxide product the choice for heat intensive, metallurgical
processes such as for production of metals, cements and glasses.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Expansion and Thermal Conductivity
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Expansion and Thermal Conductivity
Source: RHI
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Composition of Different Grade of Sintered
Magnesia
Chemical Analysis 1 2 3
CaO (%) 2.2 2.2 0.8
SiO2 (%) 0.7 0.35 0.1
Al2O3 (%) 0.1 0.2 0.1
Fe2O3 (%) 0.2 0.2 0.1
B2O3 (%) 0.015 0.02 0.005
MgO (%) 96.7 96.3 98.8
CaO/SiO2 3.1 6.3 8.0
Bulk density (kg/m3) 3400 3420 3400
Average size (mm) ~ 80 ~ 90 ~ 100
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Composition of Different Grade of Sintered
Magnesia
Source: RHI
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ternary Diagram: CaO-MgO-SiO2
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory (Brick), Slag, Glass, Cement
Melting point of pure oxides
are high, between 1700 and
2600°C.
Melting point can be lowered
by addition of the other
component.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
CaO-MgO
High liquidus and solidus
temperatures over the
complete range
100%MgO - 100% CaO.
Calcined dolomite
(CaO and MgO) have
melting point > 2300°C
Addition of magnesia
to calcined dolomite
increases
refractoriness
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-FeO
Liquidus and
solidus
temperature
decrease
rapidly when
iron oxide is
added to
magnesia
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-MnO
Magnesia is
resistance to be
attack by
manganous oxide.
Magnesia can be
used for production
of high manganese
steel.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-FeO vs. MgO-MnO
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-SiO2
Forsterite, a mineral
having the composition
2MgO.SiO2, has a
refractoriness of 1890°C
The presence of iron oxide
lower the refractorines of
fosterite
MgO.SiO2 has melting
point of ~ 1560°C
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-Al2O3
Liquidus temperature falls
steadily with addition of
alumina until 50% of
mixture.
Between 50% Alumina to
pure alumina, there is
spinel type mineral
(MgO.Al2O3) with
refracoriness of 2135°C
Spinel is used as
refractory and as a bound
for magnesis, e.g. In
induction furnace lining,
and for chrome magnesia
bricks.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
spinels are any of a class of minerals of general formulation A2+B23+O4
2-
which crystallise in the cubic (isometric) crystal system, with the oxide
anions arranged in a cubic close-packed lattice and the cations A and B
occupying some or all of the octahedral and tetrahedral sites in the lattice.
A and B can be divalent, trivalent, or quadrivalent cations, including
magnesium, zinc, iron, manganese, aluminium, chromium, titanium, and
silicon. Although the anion is normally oxide, the analogous thiospinel
structure includes the rest of the chalcogenides.
Aluminium spinels:
Spinel: MgAl2O4, after which this class of minerals is named
Gahnite: ZnAl2O4
Hercynite: FeAl2O4
Spinel
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Source of Magnesia
Source of Magnesium oxide: MgCO3, (MgO = 47.6%)
MgCO3 = MgO + CO2
The other source of magnesias are
seawater, brines or salt deposits.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Composition of Seawater
http://www.seafriends.org.nz/oceano/seawater.htm
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Source of Magnesia (cont.)
The filter cake can then be fed directly to a rotary kiln or multiple-hearth
furnaces at about 900–1300°C to convert the magnesium hydroxide to
magnesia.
This calcined magnesia is then sintered for firing into dense refractory-
grade magnesia, usually in shaft kilns which reach temperatures around
2000°C (dead burned). The end product is sintered magnesia.
Fused magnesia is produced by melting a refractory grade magnesia or
other magnesia precursor in an electric arc furnace.
Magnesium hydroxide, Mg(OH)2, is precipitated by reaction with calcined
dolomite or limestone.
2 CaO + MgSO4.MgCl2 + 2 H2O = 2 Mg(OH)2 + (CaSO4 + CaCl2)
2(CaO +MgO) + MgSO4.MgCl2 + 4 H2O = 4 Mg(OH)2 + (CaSO4 + CaCl2)
Magnesium hydroxide slurry is filtered to increase its solids content.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Effect of firing temperature on the densification,
crystal size and hydration of low B2O3 (0.03%)
pelletized magnesia
Firing temperature,
°C (1 h at temp.)
Density,
g/cm3
Crystal size,
mm
ASTM hydration
tendency, %
1600 3.11 14 91
1650 3.19 17 68
1700 3.26 23 41
1750 3.32 26 27
1800 3.37 30 21
1850 3.40 40 16
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Refractory
• High purity is quite important because MgO has high refractoriness and
good resistance to basic slags.(for converters / ladles, impurities <
2.5%, CaO/SiO2 >3, SiO2+Al2O3+Fe2O3 <0.2%, B2O3 < 0.02%)
• High density reduces infiltration and dissociation of magnesia grain
by slag. True density of periclase is 3.58. Lower density increases
total porosity. Densest body offers the best resistance to corrosion
by slags and is the strongest to resist abrasion. Desired commercial
MgO grains for converters and ladle > 3.4.
• Large crystallite size (best achieved in fused
magnesias) provides less surface area for slag
attack. (current crystallite size: 100-200 mm.
When best corrosion resistance is needed, some
fused MgO is used, the size can be measured in
several mm)
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Refractory (cont.)
• Carbon plays a vital role in minimizing the penetration of FeO containing
slag into the magnesia carbon refractory.
• (+) In the presence carbon in MgO-C refractory, iron
oxide reacts carbon from refractory. Carbon oxidation
tended to inhibit the slag penetration.
• (-) Following reaction takes place at temperature
1600°C and lower pressure of CO (e.g. in
vacuum):
MgO + C = Mg + CO
• (+) Carbon is nonwetting.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Refractory (cont.)
Source: RHI
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Refractory: MgO-C
Source: RHI
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Electric Arc Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Application of MgO: Electric Arc Furnace (EAF)
HOT SPOT
Refractory:
MgO - 14% CSlag line and
walls
Refractory:
MgO - C
Burnt MgO for
safety lining
Refractory:
MgO
MgO
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Chrome
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Chrome
Chrome ores, or chromites, often called chrome enriched spinels, are
naturally occurring members of the spinel mineral group. These materials
are all characterized by relatively high melting points, good temperature
stability (particularly in thermal union with magnesite) and moderate
thermal expansion characteristics.
Chrome ores are covered by the formula (Fe,Mg)(Fe,Cr,Al)2O4 where
magnesium can substitute for iron, and aluminum for chromium.
Cr2O3: Min.30%-45%
•SiO2: Max. 5-7%
•Fe2O3: 13-15 %
•Al2O3: 17-19%
•MgO: 8-9%
•P: Max. 0.1%
•S: Max. 0.1%
•Moisture: Max.8 %.
•CR/FE ratio: min.2.50PT. Daya Sekawan Abadi
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Chrome
Direct Bonding: chrome ore and magnesia are joined predominantly by a
solid state diffusion mechanism at temperature up to 1800°C
Pure Cr2O3 chemically separated from chromite can be used in combination
with lower cost oxides to produce specific refractory properties.
+ =
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Typical Data of Magnesite Chrome
Source UK
Co sintered
South Africa
Fused Mag.
Chrome
Canada / US
Fused Mag.
Chrome
Silica (SiO2) 1.15 1-60 1.20
Alumina (Al2O3) 5.70 7.20 6.10
Titania (TiO2) 0.20 0.20 0.30
Iron Oxide (Fe2O3) 12.50 10.70 13.00
Lime (CaO) 0.80 0.60 0.40
Magnesia (MgO) 61.50 59.90 60.10
Chromic Oxide (Cr2O3) 18.00 18.80 18.60
Bulk density (g/cm3) 3.53 3.75 3.8
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Magnesia Chrom
Chrome oxide has good resistance to slag attack. In combination with
magnesia, the magnesia-chrome products have excellent
refractoriness and spalling resistance.
Soluble hexavalent chromium compounds could be formed are
formed, leading to an environmetally unfriendly product disposal
problems due to its potentially carcinogenic characteristic
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Expansion and Thermal Conductivity
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Application of Magnesite Chrome
• Applications of magnesite chrome are similar to magnesia
• Pay attention:
- magnesia does not increase (pick-up) magnesium content in metal
- chrome containing refractories can lead to a serious chromium pick-
up in steel and discoloration of glass
• Magnesia-chrome is applied for submerged arc furnaces (SAF),
smelting furnaces for ferro alloys, copper converters, AOD lining, VOD-
ladle lining, RH plant.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
AOD Converter
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory: Mitsubishi Process
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO – Cr2O3
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Cr2O3 – FeO/Fe2O3
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Lime
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Lime
CaO has a melting point approaching 2600°C and shows a fairly high
resistance to basic slags.
It may well be asked, why this readily available material is not uses as a
principal refractory?
The answer one word is hydration. It is readily attacked by water
form calcium hydroxide.
Reaction DG at 1600°C (kcal / mole O2)
2 Ca + O2 = CaO -205
4/3 Al + O2 = 2/3 Al2O3 -175
2 Mg + O2 = 2 MgO -170
Si + O2 = SiO2 -140
4/3 Cr + O2 = Cr2O3 -110
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Dolomite
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Dolomite (Magnesia Lime)
Natural carbonate dolomite (CaCO3.MgCO3) can be converted to
refractory dolomite (CaO.MgO) by high temperature firing.
High purity dolomite: CaO + MgO > 97% , impurities 0.5 - 3%
Chemical Analysis (wt%)
Al2O3 0.45
Fe2O3 0.90
SiO2 0.70
MgO 41.2
CaO 56.7
Bulk density (kg/m3) 3250
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Dolomite Application
• Dolomite has excellent refractoriness and is thermodynamically very
stable in contact with steel or steelmaking slags.
• CaO is the most stable of the common refractory oxides at
steelmaking temperatures.
Reaction DG at 1600°C (kcal / mole O2)
2 Ca + O2 = CaO -205
4/3 Al + O2 = 2/3 Al2O3 -175
2 Mg + O2 = 2 MgO -170
Si + O2 = SiO2 -140
4/3 Cr + O2 = Cr2O3 -110
• Dolomite is used in ladle lining (steel zone). CaO in dolomite support
desulphurization of steel
(CaO) + [S] = (CaS) + [O]
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Dolomite (-)
• The free lime portion of the dead burned dolomite can react with
atmospheric moisture which causes the material to powder and
crumble. (Dolomite is more reactive to moisture than magnesia)
• The degree of hydration under set conditions of time, temperature,
and relative humidity is dependent upon the proportion of lime and
impurities contained in the material and upon the density of the grain
achieved during the dead burning process.
• In practice, with modern packaging materials and techniques together
with other means of protecting the products, the storage of dolomite
products can be extended.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
CaO-MgO
Calcined dolomite
(CaO and MgO) have
melting point > 2300°C
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
CaO – SiO2
At 50/50 mix, liquidus
temperature is 1450°C
If calcined dolomite is
heated with silica, lime
combined with silica
rather than magnesia
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
MgO-SiO2
Forsterite, a mineral
having the composition
2MgO.SiO2, has a
refractoriness of 1890°C
The presence of iron oxide
lower the refractorines of
fosterite
MgO.SiO2 has melting
point of ~ 1560°C
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
CaO - FeO / Fe2O3
a. In contact with molten iron; b. in contact with air
Low melting
point by the
ratio iron oxide
to lime is
about 4:1
If calcined
dolomite is
heated with
ferrous oxide,
lime combined
with ferrous
oxide rather
than magnesia
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ternary Diagram: CaO-MgO-SiO2
Silica additions to
doloma results in a
rapid drop in melting
point
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ternary Diagram: CaO-MgO-Al2O3
Alumina additions to
doloma results in a
slow drop in melting
point
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Silica
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Silica
1957: in the book of „Steelplant Refractories“: „Although silica continous to
meet severe competition from basic refractories of far higher melting point,
it still maintains its position as the No.1 steel plant refractory ...“
1952: LD (Linz-Donawitz) converter was first operated in Austria with 30t
vessels. The process is rapidly becoming the principal method of making
steel.
Since LD-converter demands a basic lining, silica has already lost its
prime position.
EAF and Siemens-Martins furnace roofs are changed from silica to
alumina or even to basic refractories.
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Siliceous
Natural silica occurs primarily as the mineral quartz
Natural Silica Fused Silica
Silica (SiO2) 99.70 99.60
Alumina (Al2O3) 0.09 0.20
Titania (TiO2) 0.01 -
Iron Oxide (Fe2O3) 0.09 0.03
Lime (CaO) 0.03 0.04
Magnesia (MgO) 0.01
Total alkalies 0.02 0.01
Bulk density (g/cm3) 2.33 2.20
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Thermal Expansion and Thermal Conductivity
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Fused Silica
Fused silica is produced by actual fusion of specially selected, very high
grade silica sands in electric arc, electrical resistance, or other furnace
procedures.
Crystalline raw material is converted into an amorphous glass, or fused
silica.
Fused silica has very low thermal expansion.
Fused silica products exhibit low thermal conductivity, high purity and
excellent resistance to thermal shock.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Application of Silica
Coking plant
Blast furnace stoves
Glass industries
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Clay-Alumina
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Clay and High Alumina
Although clays were among the first raw materials used to make
refractories, their usage has diminished as demands placed on modern
refractories have necessitated better performing materials.
Alumina, %
(i) Fireclay 25 – 45
(ii) Silimanite and other
Al2O3 type minerals
45 – 65
(iii) Mullite 65 – 75
(iv) Bauxite-based 75 – 90
(v) Corundum 90 – 100
Clays are still an important material in the industry.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Clay and High Alumina
Fireclay brick
High alumina brick
Mullite brick
Corundum
Corundum
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Mineralogical Classification after Calcination
Mineral Name Chemical Formula Alumina %
Kaolinite Al2O3.2SiO2.2H2O 45.9 (say 45)
Silimanite
Kyanite Al2O3.SiO2 63.0 (say 65)
Andalusite
Mullite 3Al2O3.2SiO2 71.8 (say 75)
Bauxite (pure) Al2O3.2H2O 100.0 (say 100)
Corundum (pure) Al2O3 100.0 (say 100)
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Bauxite
Bauxite in the crude state is a naturally occurring group of minerals
composed primarily of either gibbsite (Al2O3•3H2O), diaspore, or
boehmite [AlO(OH)], and various types of accessory clays.
Refractory grade calcined bauxites are are produced from low iron, low
silica materials in rotary kiln calcining operations. Calcining
temperatures are in the 1400–1800°C range. Crude bauxite is
converted to the minerals corundum (Al2O3) and mullite (3Al2O3•2SiO2).
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Al2O3 - SiO2
Alumina, %
Fireclay 25 – 45
Silimanite
and other
Al2O3 type
minerals
45 – 65
Mullite 65 – 75
Bauxite-
based
75 – 90
Corundum 90 – 100
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
High-Alumina FireBricks
http://www.skylinecomponents.com/AluminaFirebricks.h
tml
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
CaO – Al2O3 – SiO2
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Applications
Industry Installation Location
Iron and steel Cupola Linings
Blast furnace Linings
BF stoves Linings
Torpedo ladles Linings
Hot metal mixers Linings
Ladles Linings
Induction furnace Linings
Continous casting Nozzles, tundish lining,
extension tubes, stopper
rod
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Applications
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Application
Stack
Belly
Bosh
Tuyere breast
Hearth
Refractory (Typical)
Corundum (Al2O)
Andalusite (Al2O3.SiO2)
Silicon Carbide (SiC)
Corundum (Al2O)
SiC, Corundum
Andalusite
Graphite
Silicon Carbide
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Carbon
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Carbon
The graphite may be synthetic in nature as produced by heating calcined
petroleum coke to 3000°C or may be natural graphite(s) from China,
Mexico, Canada etc.
Some carbon or all graphite refractories may be produced for applications
in highly reducing atmospheres.
Generally, graphites are used in refractories in order to reduce the wetting
characteristics of the refractory material with respect to slag corrosion and
to increase the thermal conductivity which will result in better thermal shock
resistance.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Carbon
In oxide-carbon refractories, the carbon content may range anywhere from
as low as 4–5% up to as high as 30–35%.
Note: as the graphitic content increases, the thermal conductivity of the
refractory increases, but the density of the refractory decreases.
This result is primarily due to the fact that the density of graphite is much
less than the density of the other refractory materials being used.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Application of Carbon Refractory
Industry Installation Location
Iron and steel Blast furnace Hearth (carbon brick,
graphite)
Ferro alloys (FeSi, FeCr,
FeMo)
Furnaces Hearth (carbon brick,
graphite)
Steel Electric Arc Furnace Electrodes (graphite)
Aluminium Smelters Anodes, cathodes,
sidewalls, hearth
(petroleoum coke)
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Conductivity and
Heat Transfer
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Conductivity and Heat Transfer
Refractory materials have always been used to conserve heat, and their
resistance to heat flow is a prime selection factor in many applications.
Heat transfer losses through single or multiple component refractory
walls can be calculated using the general formula:
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Conductivity and Heat Transfer
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Page 107
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Thermal Expansion and Thermal Conductivity
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Refractory
Preheating
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle Preheating
Vertical preheating Horizontal preheating
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle (Refractory) Heating
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle (Refractory) Preheating / Heating
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle Drying Curve
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Ladle Heat Up Curve
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Copper Cooling
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Furnace Cooling System
There is a trend to apply cooling system on / in the lining systems to
perform ten to fifteen years operation with a minimum repair.
By inserting water-cooled copper elements in the furnace brickwork, a
frozen slag on the refractory hot face will be formed. This frozen slag
protects the bricks from further erosion/corrosion by the liquid slag.
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Copper Cooler
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Copper Cooler
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Copper Cooler
Page 120
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Some Refractory
Applications
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Electric Arc Furnace (EAF) - Roof
Bauxite or
Corundum
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LD Converter (Vessel Preheating)
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Induction Furnace
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Induction Cooking
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Typical Component of Induction Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace Lining
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace Lining
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Induction Furnace
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Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Summary
• Refractory: brick / shape and castable
• Refractory: Acid, Basic, Neutral
• Refractory: MgO, Dolomite, MgO-Cr2O3, Silica, Clay and Alumina,
Carbon
• Preheating
• Copper cooling application for refractory
• Refractory: Applications
Page 133
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Main References
1. Schacht, C.A., Refractories Handbook, Marcel Dekker, 2004
2. Chesters, J.H., Refractories: Production and Properties, The
Institute of Materials, 1973
Page 134
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG3111 Pyrometallurgy
Terima kasih!Program Studi Teknik Metalurgi
Fakultas Teknik Pertambangan dan Perminyakan
Institut Teknologi Bandung
Jl. Ganesa No. 10
Bandung 40132
INDONESIA
www.metallurgy.itb.ac.id
Dr.-Ing. Zulfiadi Zulhan, ST., MT.
[email protected]
Taufiq Hidayat, ST., M.Phil., Ph.D.
[email protected]
D.Sc. (Tech.) Imam Santoso, ST., M.Phil
[email protected]