Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
04. Material Preparation: Agglome-
ration, Drying, Calcination, Roasting
Pyrometallurgy (MG-3111)
5th Semester – 2021/2022
Zulfiadi Zulhan
Taufiq Hidayat
Imam Santoso
Department of Metallurgical Engineering
Faculty of Mining and Petroleum Engineering
Institut Teknologi Bandung
INDONESIA
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 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
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Course Content
1. Introduction
2. Refractory
3. Slag
4. Material Preparation: Aglomeration, Drying, Calcination, Roasting
5. Carbo- / Aluminothermic (Metalothermic)
6. Smelting, Refining
7. Pyrometallurgy of Copper Production I
8. Pyrometallurgy of Copper Production II
9. Mid Exam
10. Pyrometallurgy of Tin Production
11. Pyrometallurgy of Nickel Production(Nickel Matte, FeNi)
12. Pyrometallurgy of Zinc and Lead Productions
13. Production of Ferro Alloy I (FeMn)
14. Production of Ferro Alloy II (FeCr, FeSi)
15. Group Presentation (FeNb, FeMo, FeTi, FeV, FeTa, FeW, CaSi, CaC2 etc.)
16. Final Exam
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Learning Activity Objectives
After completing this learning activity, the course participants should be
able:
1. to state the reason for agglomeration and to list and describe the types
of aglomeration equipment used in industrial processes
2. to state the purpose of and be able to list types of roasting operations
3. to state the reason for drying and calcining and able to list and
describe the types of drying and calcining equipment used in industrial
processes.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Process Flow Diagram:
Production of Ferronickel Pomalaa, PT Aneka Tambang
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
EB Mine
Hi Recovery
Low Olivine parent
WB Mine
Low Recovery
High Olivine parent
Process Flow Diagram:
Production of Ni matte at Soroako PT Vale
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Copper Smelter
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Mitsubishi Continuous Process (Naoshima)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
AGLOMERATION
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Agglomeration
The primary purpose of agglomeration is to improve burden permeability
and gas-solid contact.
A good agglomerate :
• should contain a minimum of undesirable constituents, a minimum of
material less than 6 mm, and a minimum of material larger than 25
mm.
• should be strong enough to withstand degradation during stockpiling,
handling, and transportation.
• must be able to withstand the high temperature.
• should be reasonably reducible.
Sludge and Dust from Dedusting System shall be aglomerated first
before they are charged into kilns or furnaces.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Agglomeration
S: The making, shaping and treating of steel, 11th Edition Ironmaking Volume, the AISE Steel Foundation, 1999
Sinter
Pellet
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Definition
Sintering and pelletising are processes by which ore (fines / dust /
sludge) are agglomerated into larger pieces with or without
incorporation of lime and magnesia as fluxes.
Pellet Sinter
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
AGLOMERATION:
Pelletizing
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Pellet
1st patent of pelletizing in rotating drum:
• Anderson, Sweden, 1912
• Brakelsberg, Germany, 1913
For Pelletizing:
Binder : bentonite (Al2O3.4SiO2.H2O), clay or hydrated
lime
consumption: 6.3 – 10 kg / ton of feed
Water : Optimum moisture content is 9-12%
Pelletisation is a process of agglomeration of ore fines. Particles smaller
than 0.2 mm are converted into 12-15 mm green pellets. On drying and
firing, green pellets become hard and strong to be used as feed for
furnaces.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Typical Chemical Composition of Magnetite Pellet
Feed
%
Fe 65.5
SiO2 7.8
Al2O3 0.5
CaO 0.5
MgO 0.6
Mn 0.25
P 0.032
S 0.003
TiO2 0.1
Moisture 10
Grain size: < 0.2 mm
70-80% < 40 mm
S: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Properties of Bentonite
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Green Ball Formation
When two ore particles
which are coated with binder
slurry come in contact with
each other due to motion on
a pelletising machine, they
collide with another particle
to form liquid bridge acting
as capillary. Surface tension
of the fluid capillary keep the
particle together
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Methods to produce green pellet
6 - 10°
Cone
Drum
Disk
S: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Drum to produce green pellets
Dimension of rotating drum for green pellet production with
capacity of 90-130 t / hS: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Drum
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Angle =
45-48°
Rotating Disk to produce green pellets
Dimension of rotary disk for green pellet production with capacity
of 90-140 t / h
S: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk to produce green pellets
S: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk to produce green pellets
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk to produce green pellets
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk to produce green pellets
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Disk to produce green pellets:
Pyrometallurgy Laboratory
Mini Rotating Disc Pelletizer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Cone to produce green pellets
Mixture ready for balling
Green PelletsS: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Drum vs. Disc
The balling drum and the disc pelletizer are the most widely used
devices for forming green balls
Disk
(+) Lighter weight
(+) Greater possibility for adjustment e.g. instantaneous fluctuations in the
feed
(+) Classifying action promotes discharge of balls of more uniform size,
which simplifies screening of the product.
(-) Capacity of the discs is low
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Pellets Hardening
• Green pellet is hardened by heating (firing at sufficiently high
temperature, ~ 1200°C)
• Methods for Pellet Hardening:
traveling grate
grate-kiln
shaft furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Typical Pelletizing Plant
S: The making, shaping and treating of steel, 11th Edition Ironmaking Volume, the AISE Steel Foundation, 1999
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Pellet Hadening (Traveling Grate)
S: The making, shaping and treating of
steel, 11th Edition Ironmaking Volume,
the AISE Steel Foundation, 1999
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotating Drum + Pellet Hardening (Grate Kiln)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
AGLOMERATION:
Sintering
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Sintering
Definition: burning of fuel (coke breeze, anthracite) mix with iron bearing
material, e.g. Fine ore, concentrate, metal shop waste (dust, miling scale,
sludge, etc.) under controlled conditions.
Iron ore : 55.5%
Circulation Komponet : 4.8%
Fluxes : 12.7%
Return material : 27%
Raw mix : 100%
Composition of Sinter Mix
(example for iron ore):
Raw mix : 92.1%
Coke breeze : 2.3%
Moisture : 5.6%
Sinter mix : 100%
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Sintering
Air
Sinter< 5 mm
iron ore
Coke fines
Limestone fines
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zonen während des Sintervorganges und
Temperaturverlauf (5.8 minutes after ignition)
200 400 600 800 1000 1200 140000
02
04
06
08
10
12
14
16
18
20
Temp. °C
Sin
tering b
ed d
ep
th (
cm
)
Cooling zone
Oxidation zone
Sinter zone
Ignition zone
Drying zone Separation of
crystalline water
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Schematic Diagram of Iron Ore Sintering Process
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Sintering
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Typical Chemical Composition of Sinter
%
Fe total 56.33
Mn 3.99
P 0.04
SiO2 5.83
CaO 11.05
MgO 1.85
Al2O3 1.14
CaO/SiO2 1.9
S: H.-W.Gudenau, Eisenhüttenmännische Verfahrenstechnik,
Vom Erz zum Stahl, Materialsammlung zum Praktikum, IEHK-RWTH Aachen, 1989
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
AGLOMERATION:
Briquetting
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting
Metallurgical processes produce
frequently substances that due to
their of fineness are unsuited for
further use.
Briquetting or compaction
processes enables a product of
defined size for further utilized /
processed.
Via a feeder system, material is
introduced into a space above
two rotating rollers. When
passing through the roller gap,
material is compacted and
formed into product.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting
Roller technology has been applied for more than 150 years.
Roller press consists of the following main assemblies:
• Press frame
• Floating and fixed rollers
• Main drive
• Material feeder equipment
• Hydraulic and pressurizing system
Briquetting is used in the following metallurgical industry:
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting
Rollers carrying the pressing tools. The roller’s surface is designed to meet
specific requirements and suited for the feed to be processed.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
• Thermoplastic binders (e.g. pitch, bitumen, plastics, waxes, resins)
• Mortar binders (e.g. lime mortar, gypsum, cement)
• Clay binder (bentonite)
Chemical Formula of Bentonite:
Physical Properties :
Al2O34SiO2H2O
Sp. Gravity : 2.4
Bulk density : 0.6
PH of 10% Aqueous solution: 8 to 8.8
Chemical Composition :
Silica : 54.26
Aluminium : 18.34
Ferric Oxide : 10.91
TiO2 : 01.25
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting of Hot Sponge Iron
Briquetting machine (typical for HBI) consists of
following elements:
1. Roller press with screw feeder
2. Briquette string separator
3. Double deck hot screen
4. Vibrating deck hot screen
5. Hot fines recirculation
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting of Hot Sponge Iron
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Briquetting of Hot Sponge Iron
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Extrusion
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Extrusion
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Extrusion
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DRYER
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Drying
Drying: removal of water (bulk and / or adsorbed „surface held“
moisture) from other substances (ore or coke) by evaporation.
Drying at atmospheric pressure: heating the substance above normal
boiling point of water (100-200°C).
Evaporation of water is an endothermic process:
H2O(l) = H2O(g) DH298 = 43.9 kJ
Drying is accomplished by passing hot combustion gases through or
above the substance.
In most integrated metallurgical plant, hot gases which have temperature
of a few hundred degress celcius is used.
If hot gases is not available, extra fuel has to be burned.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Drying
Drying can be carried out in a number of different types of furnaces:
- Rotary dryer
- Fix bed furnace
- Fluidized bed furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Fluidized Bed: Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
A rotary dryer consists of a cylinder, rotated upon suitable bearings and
slightly inclined to the horizontal.
Diameter : less than 0.3 to more than 3 m
Length : from 4 to more than 10 times its diameter
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Rotary dryers can been classified as direct and indirect.
“direct”: if heat is added to or removed from the solids by direct exchange
between flowing gas and solids
“indirect”: if the heating medium is separated from physical contact with
the solids by a metal wall or tube.
Usually carbon steel is used as material for cylinder. No lining is needed,
temperature 650-700K
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer: Flight / Lifter
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer: Flight (Lifter) Arrangement
Direct-heat rotary dryer is usually
equipped with flights on the interior for
lifting and showering the solids
through the gas stream during
passage through the cylinder.
These flights are usually offset every
0.6 to 2 m to ensure more continuous
and uniform curtains of solids in the
gas.
Shape of flights depends upon the
handling characteristics of the solids.
For free-flowing materials, a radial
flight with a 90° lip is employed.
For sticky materials, a flat radial flight
without any lip is used.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer: Flight (Lifter) Arrangement
When materials change characteristics
during drying, the flight design is
changed along the dryer length.
Many standard dryer designs employ:
• flat flights with no lips in the first one-
third of the dryer measured from the
feed end,
• flights with 90° lips in the final one-
third of the cylinder.
• flights with 90° lips in the final one-
third of the cylinder.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer: Retention Time
Retention time:
θ = time of passage, min
S = slope, ft/ft;
N = speed, r/min;
L = dryer length, ft
D = dryer diameter, ft
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Drying: Co-Current
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Drying Rate
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Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Ore
Hot gas
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer (Hot Gas Producer)
Pulverized Coal
Hot gasAir
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Ore
Hot gas
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Dryer
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
CALCINATION
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Calcination
Calcination: processes designed to decompose or partially decompose a
compound
removal of chemical bound water (hydrates) and gases (CO2 from carbonates,
SO2 from sulfates)
Calcination is more endothermic than drying.
Heat must be supplied at relatively high temperature
Temperature required for calcining is depending on the compound to be
treated.
Term „calcine“ was originally used to describe the product produced by
decomposition of magnesium and calcium carbonates, hydrates and
hydroxides.
However, this term is now used also for roasted copper sulfide concentrates,
roasted zinc sulfide concentrates, partial reduction of nickel oxide, etc.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Decomposition Pressure of Various Carbonates
and HydratesL
og
pC
O2,
(H2O
), a
tm
FeCO3 and Mg(OH)2,
T< 200°C
MgCO3, T ~ 400°C
CaCO3, T ~ 900°C
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Calcination
Calcination can be carried out in:
- Shaft furnace (for coarse sizes)
- Rotary kiln (for mixed particle size, for lumps which disintegrade during
the process)
- Fluidized bed (for uniform small particle size)
Solids in
Product out
Fluid out
Fluid in Gas in
Gas out + dust
Solids in
Solids
out
Shaft furnace
Rotary Kiln
Fluidized bed
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime making (Calcination) in Shaft Furnace
CaCO3 = CaO + CO2, DH298 = 177.8 kJ
Heat must be supplied at relatively high temperature. Calcination rate is
governed primarily by supply of necessary heat for decomposition.
Decomposition of limestone ~ 900°C.
Calcination in Shaft Furnace:
Furnace is charged with a mixture of limestone and coke.
Air is introduced at the bottom of the furnace, where burned is withdrawn.
Furnace can be divided into three zones:
1. Preheating zone : solid charge is preheated to 800°C
2. Reaction zone : burning of coke and decomposition of limestone
take place
3. Cooling zone : burned lime is cooled to 100°C.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Thermodynamic Data for Calcination of Limestone
CaCO3 (s)⇔CaO (s) +CO2 (g) DH298 = 177.8 kJ
DG° = 182837 + 13.402 T ln T − 251.059 T J mol−1
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Decomposition of calcium carbonate as function of
temperature
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime making (Calcination) in Shaft Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime making (Calcination) in Shaft Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime making (Calcination) in Shaft Furnace
0.56 or (183/328) mol of carbon is required per mole of CaCO3
0.56 mol C ~ 0.067 kg carbon per kilogram CaCO3.
In practice, amount of carbon required per kg CaCO3 ~ 0.1 kg to
cover heat losses through furnace wall.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
ROTARY KILN
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln
Rotary kiln: a long, narrow cylinder inclined 2 to 5 degrees to the
horizontal and rotated at 0.25 to 5 rpm.
The length/diameter ratio ranges from 10 to 35, depending on the reaction
time needed.
Refractory lining is needed (due to high temperature processes~700-
1400°C).
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln
Formulas for capacity and residence time in terms of operating conditions:
W = 148 n D3 tan ϑ in t/(m3⋅d)
in hours
where n = rpm
= fraction of cross section occupied
D = diameter, m
L = length, m
ϑ = degrees inclination to the horizontal
tan D n 60
L
=
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln
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Rotary Kiln: Sealing
Rotate
Static
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Rotary Kiln
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Rotary Kiln: Burner
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln: Burner
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Functional Principle of Rotary Kiln
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Heat Transfer in Rotary Kiln
Radiation
Heat transfer from
burner flame and
from refractory
Most heat transfer in
a Kiln is by Radiation
Convection
Heat transfer from
the process gases to
the material
Conduction
Heat transfer from
the hot brick in
contact with the
material
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime Making in Rotary Kiln
From fuel requirement: rotary kiln is flexible
Fuel: natural gas, fuel oil, pulverized fuel (coal,
coke, sawdust)
88% of burned lime is produced by rotary kiln.
L/D ~ 30-40, L ~ 22.7 – 152.5m, D ~ 1.2-3.3m
Slope ~ 3-5°
Degree of fill ~ 10-12%
Thermal consumption:
Without heat recuperation: ~ 3336 – 4170
kcal/kg of lime
With heat recuperation: ~ 1668 – 2224 kcal/kg
of lime
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime Stone Dissociation Process Steps
1. Heat is transferred from the furnace gases to the surface of the decomposing
particle.
2. This is followed by heat conduction from the surface to the reaction front
through the micro-porous lattice structure of lime.
3. Heat arrives at the reaction front and causes the dissociation of CaCO3 into
CaO and CO2.
4. The CO2 produced migrates from the reaction front, through the lime layer, to
the particle surface.
5. CO2 migrates away from the particle surface into the kiln’s atmosphere.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Solid B
C
A
Shrinking – Core Model for Spherical Particles of
Unchanging Size
Fluid A
A (fluid) + b B (solid) = c C (fluid) + d D (solid)
Fluid phase mass transfer
(STEP1)
Fluid phase mass transfer
(STEP 5)
C A bulk
C C bulk
T bulk
Chemical
Reaction
(STEP 3)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime Making in Rotary Kiln
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Lime Kiln, Heat and Material Balance
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cement Making in Rotary Kiln
Rotary Kilns are synonymous with cement making.
Raw materials (CaCO3, Al2O3, Fe2O3, SiO2) are charged to
produce:CaO·SiO2 (C3S), 2CaO·SiO2 (C2S), 3CaO·Al2O3 (C3A), and
4CaO·Al2O3·Fe2O3 (C4AF).
Kiln is divided into three zones:
- decomposition zone (900°C),
- transition zone (900-1300°C), and
- sintering zone (1300-1400°C).
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cement Making in Rotary Kiln
Decomposition zone:
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cement Making in Rotary Kiln
Transition zone:
Sintering zone:
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cement Making in Rotary Kiln
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cement Making in Rotary Kiln
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
▪ Calcination is carried out in Rotary Kiln to remove moisture
(hydrates water from ore) and LOI (loss on ignition). Partial
reduction is also performed in rotary kiln using counter current
principles.
▪ 20% NiO is reduced to Ni and 80% Fe2O3 to FeO in the rotary kiln
▪ Hot gas in rotary kiln is produced by pulverized coal combustion at
the calcine discharging end. Temperature of hot gas ~ 12400C. Hot
gas will heat the material up to 10200C near the discharge end.
▪ Hot spot of the burner flame may reach over 18000C and will heat
the material up to partial fusion (clinker).
Rotary Kiln (PT Aneka Tambang)
114
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln (PT Aneka Tambang)
115
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln
116
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Reduction Kiln (PT International Nickel Indonesia)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln (PT International Nickel Indonesia)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln SL/RN Process
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Rotary Kiln SL/RN Process
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Roasting
Aim of roasting:
1. Conversion of material to the oxide form as prelimanary to a metal
extraction
2. Formation of water soluble sulphates which can be employed in in
subsequent hydrometallurgical processes.
Typical ores which are roasted: sulfides of copper, nickel, zinc and lead.
Roasting is carried out below melting point of sulfides, usually below 1000°C
From kinetic point of view, temperature should be above 500°C
Temperature range: 500-1000°C.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Equations:
K log- p log p log 2
2MeSO O 2SO 2MeO 4.
4OSO
422
22=+
=++
K log - p log
MeO 2 O 2Me 2.
2O
2
2=
=+
K log p log 3 - p log 2
2SO 2MeO 3O 2MeS 3.
3OSO
22
22=
+=+
K log p log - p log
O MeS SO Me 1.
1SOO
22
22=
+=+
K log - p log 2
MeSO 2 2O MeS 5.
5O
42
2=
=+
p log K log p log 2 - p log 2
SO 2 2O S 6.
222 S6OSO
222
+=
=+
p log 2 K log- p log p log 2
2SO O SO2 7.
322 SO7SOSO
322
+=+
=+
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Schematic: Equilibria and Predominance Areas at
Constant Temperature (Kellog diagram) for System
Me-S-O
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Roasting Equipment
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Roasting Equipment: Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Multi Hearth Furnace
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Roasting Equipment: Fluidized Bed
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Fluidized Bed
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Fluidized Bed: Combustion
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Ni-S-O System
When nickel sulfide (NiS) is roasted in an oxygen bearing atmosphere,
nickel oxide (NiO) or nickel sulfate (NiSO4) is formed, depending on
temperature, pO2 and pSO2
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Equilibrium constant data for different reactions in
Ni-S-O System
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
In a roaster operating
at total pressure of 1
atm, gas composition in
the range 3-10% O2
and 3-10% SO2, nickel
suphate will be
produced
If gas phase containing
1% O2 and 1% SO2,
nickel oxide will be
formed
Determine which phase
is most stable when log
pSO2 = -1 and log pO2 =
-12. Total pressure is 1
atm
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1:
Nickel sulfide concentrates with 60% NiS and 40% SiO2 are roasted in a
fluidized bed reactor using oxygen-enriched air. The composition of the gas
phase is found to be 10% SO2, 7.5% O2 and 82.5% N2. Temperature and
pressure in the reactor are steady at 1000°K and 1 atm. The roasted
product is found to contain 2.4% S.
a. Which solid phases are present in the solid product and in what
amount?
b. What is the oxygen content of the enriched air used in the operation?
c. How much air is required per 100 kg of concentrate?
d. How much heat is lost to the surroundings? (assume that the
concentrates and the air enter the reactor at 298°K and the gaseous
and solid products leave it at 1000°K)
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1
The following data are given:
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, a.
Consider 100 kg of concentrates as basis:
Amount of Ni = 38.83 kg
Amount of S = 21.17 kg
Kmol of Ni = 0.6615
Gas phase contain SO2 and O2,
pSO2 = 0.1 atm, log pSO2 = -1
pO2 = 0.075 atm, log pO2 = -1.1249
From diagram, solid product = NiSO4
However, sulphur content in the roated product is too small (2.4%S).
The product may contain NiO and NiSO4
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, a.
Suppose that the weight of roasted product is w kg
Amount of sulphur in the product = 0.024w kg
Kmol of sulphur =
Kmol of NiSO4 in product =
Kmol of Ni present as NiO = 0.6615 –
Amount of NiSO4 = kg
Amount of NiO = kg
Amount of SiO2 = 40 kg
89.42 + 0.06 w = w; w=
Product: NiO = 44.08 kg, NiSO4 = 11.04 kg, SiO2 = 40 kg
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, b and c.
Suppose that the volume of enriched air supplied is y m3 at STP.
q is volume percent of O2 in dry air.
Volume of O2 supplied = 0.01 qy m3 at STP
Volume of N2 supplied = y -0.01 qy m3 at STP
Kmol O2 supplied = 0.01qy/22.4
Kmol N2 supplied = (y -0.01 qy)/22.4
Volume of gaseous products at STP from reactor is z m3
Volume of O2 in products = 0.075 z m3 at STP
Volume of SO2 in products = 0.1 z m3 at STP
Volume of N2 in products = 0.825 z m3 at STP
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, b and c.
kmol of O2 in products = 0.075 z/22.4
kmol of SO2 in products = 0.1 z / 22.4
kmol of N2 in products = 0.825 z/22.4
Oxygen balance:
O2 input = O2 in gases (as O2 and SO2) + O2 as NiO + O2 as NiSO4
0.01 qy = 0.175 z + 9.8111
Nitrogen balance:
N2 input = N2 output (as O2 and SO2)
y - 0.01 qy = 0.825 z
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, b and c.
sulphur balance:
S in NiS concentrate = S in NiSO4 + S in SO2
0.6615 = 0.07136 + 0.1 z / 22.4
z = 132.27 m3; y = 142.08 m3; q = 23.2 %(vol.)
Volume air required = 142.08 m3
Oxygen content of enriched air = 23.2%
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Example 1: Solution, d
Reactions:
NiS + 3/2 O2 = NiO + SO2
NiS + 2O2 = NiSO4
Heat losses = 132 502 kJ
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cu-S-O System
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Cu-S-O System
The purpose of copper
sulfides roasting is to produce
either CuO product or water
soluble CuSO4 product
T < 677°C CuSO4 is stable
T > 800°C CuO is stable
T ~ 677- 800°C CuO.
CuSO4 is stable
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Fe-S-O System
If in concentrate copper contains
Fe, i.e. chalcopyrite (CuFeS2),
roasting temperature should be
considered:
At T > 677°C, Fe2O3 is stable!
For hydrometallurgy process:
Roasting temperature: 677-
800°C, product: CuO.CuSO4
and Fe2O3
In subsequent pyrometallurgy
process, the presence of
Fe2O3 (or Fe3O4) leads to
over oxidation condition.
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
8% SO2 and 4% O2,
CuSO4 and Co SO4
are stable
In case of Cu and Co
will be separated by
leaching, then
roasting operation
should be in area „A“
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Pb-S-O System
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Pb-S-O System
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Extraction of Mercury from Cinnabar
Mineral Cinnabar is a relatively pure form of HgS, the metal can be
obtained by direct oxidation:
HgS(s) + O2(g) = Hg(l) + SO2(g) DGo = -57000 – 8.6 T cal
Hg (l) = Hg(g) DGo = 14100 – 22.4 T cal
Or:
HgS(s) + O2(g) = Hg(g) + SO2(g) DGo = -42100 – 31.0 T cal
Zulfiadi Zulhan/Taufiq Hidayat/Imam Santoso 2021 MG-3111 Pyrometallurgy
Roasting Flash Smelting
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.
Taufiq Hidayat, ST., M.Phil., Ph.D.
D.Sc. (Tech.) Imam Santoso, ST., M.Phil