Advanced Alumina Solutions
2
Bauxite crushing & grinding
Bauxite
Bauxite ore is the major mineral
source for extraction of alumina and
subsequently aluminium, the most
abundant element found in the
earth’s crust. The name bauxite
originates from France where it was
discovered. There are three (3) main
structural types of bauxite:
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World’s largest Rod Mills on Bauxite
at Gove, Australia
Gibbsite – Al(OH)3
Boehmite – AlO(OH)
Diaspore – AlO(OH)
Each of these three types of bauxite
has different chemical and physical
properties that make them more or
less difficult to mine and subsequently
use for economically refine to
alumina.
Of the bauxites currently being mined,
the dominant form is gibbsite,
followed by a mixture of gibbsite and
boehmitic. The main impurities are
compounds of iron, silicon and
titanium.
4400 t/h Primary ABON Sizer
crushing bauxite
2500 t/h Secondary ABON Sizer
crushing bauxite
A large quantity of the world’s bauxite
is mined from large blanket type
deposits with an overburden from 0
to 70 m of rock and/or clay, which
may require blasting before being
loaded by front end loader or shovel
and transported by truck, rail or
conveyor to the refinery.
Processing
At the refinery, the bauxite is stored in
a stockpile by a stacker for later
reclaiming and processing into
alumina. Roller screening of the
bauxite to remove coarse waste
material may be the first unit
operation before the bauxite is
crushed in one or more stages to a
particle size of about 50 - 75 mm,
before being mixed with a hot caustic
soda solution in the grinding mills.
ABON® sizers
Since most bauxite mines are located
in the tropics with its rainy season,
bauxite processing equipment must,
as a rule of thumb, be able to handle
wet and sticky bauxite as well as dry
and dusty bauxite, which makes the
ABON Mineral Sizer the preferred type
of crusher selected for both primary,
secondary and tertiary crushing of the
bauxite in many cases.
Ball or rod mills, rod-ball mill
or SAG mill
After crushing, wet grinding of
bauxite is accomplished in either open
or closed-loop milling circuits using
various types of grinding mill designs,
tailor made to the bauxite.
FLSmidth has operating experience
with all the above equipment and
cover the complete equipment flow
sheet from Run-of-Mine bauxite up to
and including the de-silication tank
reactor prior to digestion.
3
Solid liquid calcination (SLC)
The SLC process converts spent plant
liquor and Sodium Oxalate to Sodium
Aluminate and recovers the Caustic
from Sodium Carbonate using Bauxite
and/or Alumina Dust
as solid feedstock.
Liquor productivity is increased by
decreasing content of organic agents
and sodium carbonate in the liquor,
allowing an increase in caustic
concentration.
Quality of hydrate and alumina is
improved by reduction of sodium in
alumina and production of a coarser
hydrate.
Improved plant efficiency is achieved
by:
• Recovery of dissolved caustic and
alumina
• Lower viscosity of plant liquor
and pumping power
• Increased settling rates and less
foaming
• Utilization of high organic
bauxite deposits without
decreasing plant efficiency
• Environmentally sound processing
of salt cake to sodium aluminate
without additional residue
generation
R&D timeline of SLC process
1st generation 120 TPD Solid Liquid
Calciner with Alcan and Alumina
Espanola.
1992-1993: Equipment Selection
1993–1996: 24 tpd Pilot Testing
1997–1999: Construction of 120
tpd Unit
1999–2000: Commissioning,
Demonstration,
Consolidation and
Optimization;
2nd Generation SLC Process
developed with Alcan for Liquor
Purification at Gove, Northern
Territory
2002: Pilot Testing - Gas Suspension
2003: Pilot Testing - Environmental
2004: Basic Engineering
2004: Environmental impact study
2005: Detailed Engineering
2005-2006: PAM Construction
2 x 300 SLC Units arrives (as PAM) to the Gove Refinery
in Australia
Liquor Purification with the Solids Liquid Calcination Process
(SLC)
4
Settler & washer trains
Deep Cone® paste thickeners
• Maximum underflow slurry solids
and minimum thickener footprint
• Produce uniform, nonsegregating paste consistency
underflow slurry
• State of the art approach for dry
stacking of red mud
• Torque capacities available to
13,500,000 Nm
• 138 Deep Cone Paste Thickeners
sold to over 45 operating sites
Main features
• E-Duc® autodilution and
flocculation feed systems
(for washers)
• Mud bed in compression
• Rakes with pickets for increase of
solids concentration
• High torque drives
• Steep floor slope
• Mud discharge cone with
centre scraper
• Designs without bottom bearing
available
Hi-rate thickeners
• Technology for high specific
capacity at reduced footprint
• In combination with red mud
drum filters for mud disposal at
highest solids concentration and
minimum soda losses
• Advanced mud level and
thickener control systems
available
New generation of drive
heads — A-type
• State-of-the art design for bridge
type thickeners
• Multiple efficiency planetary
gears replacing traditional worm
gear arrangements
• Heavy duty, high precision
4-point contact ball bearing
designed to handle tilting forces
• Reverse rotation feature
• Permanent torque measurement
by load cell(s)
• High safety span between design
torque, 100% - alarm and cut-off
at 180% resulting in extended
reaction time for corrections
5
Red mud filter
Red mud filters
• 22 mm high flow filter cells for
highest hydraulic and pneumatic
capacities
• Air sweeping device at both ends
of the drum cell to assure quick
filtrate and cake discharge
• Large diameter (1000 mm dia.)
vacuum valve and wear plate
with large sealing area for long
resistance to wear
• Dedicated discharge roller drive
system – allowing for optimising
ration of drum vs. discharge
roller speed
• Agitator drive is designed for
easy maintenance access to the
drive, the bearings and the
eccenters; especially the agitator
shaft is divided in such a way,
that also inside eccenter-bearings
can be dismantled and replaced
without disassembling the
eccenter and the outside bearing
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Agitator drive is supported on the
filter vat (not on the foundation)
for best fit of components in the
workshop and after site erection
Robust cake discharge comb in
special red mud design
Agitator pivot bearings can be
replaced from the outside
without disassembling the drum.
They are provided with
lubrication points to assure to the
bearings a long life
Mud pockets with sluicing pipes
and drainage nozzles to
temporarily drain out the
settled sand
6
Pressure filtration
Shriver® Filter Press
The FLSmidth Shriver® automated membrane filter presses are
supplied with overhead filter plate suspension and automatic
indexing plate shifting. These rugged construction filter presses
are fitted with automatic high-pressure cloth washing mechanisms for filter cloth cleaning at pressures up to 100 bar.
Years of experience and thousands of installations have resulted in
a wide array of designs, features and styles of Shriver® filter
presses. A variety of plates, skeletons, opening mechanisms,
shifters, and special designs with patented Shriver options
provides FLSmidth the knowledge and experience to handle the
most complex to the simplest application.
AFP IV™ automatic filter presses
The FLSmidth AFP IV™ automatic filter press offers considerably
reduced cycle time as compared to conventional filter presses.
The mechanical time between cycles is minimal and, as a
result, more production is achieved.
Benefits
• High-solids red mud filter cake
• Maximum caustic recovery
• Overhead Plate Suspension
• Automatic filter cloth washing at 100 bar
• Filtration area up to 1,000 square meters
Benefits
• High-solids red mud filter cake
• Maximum caustic recovery
• Positive, fully automatic cake discharge
• Easier operation and maintenance accessibility
• Lower maintenance costs and higher performance
• Filtration area up to 2,000 square meters in a single filter
Features
• Over 100 years experience in process and design
• More than 30,000 installed units worldwide
• Flexibility in design to meet special needs
• Qualified and experienced technical staff
• North American technologies combined with local manufacturing, local service and spare parts
The selection of AFP IV™ filter presses can greatly reduce the
number of installed filters for a given installation. These filters
not only provide high throughput, efficient solids capture and
low moisture content red mud filter cakes, but they also
operate continuously and automatically in harsh environments,
and can handle abrasive or corrosive slurries.
Features
• Push closure cylinder mounted at centerline of filter press
• Rolling cross-head for extra long plate-stacks
• Fast opening & closing w/shaker for quick cake discharge
• Heavy-duty design specially adapted for minerals service
• Automatic cloth washing apparatus
• Recessed chamber and membrane plate designs
• Filter Press Control Packages – Automatic filtration, cake
wash, membrane squeeze, & discharge. Local process
control and DCS communication.
7
Mobile conveyors & dry stacking
Mobile conveyors
The mobile stacking conveyor can be
used to handle various materials. It is
a single conveyor supported on a
series of truss frames and crawler
tracks. The trusses are connected by a
specially developed joint that allows
the machine to follow uneven ground
conditions and relieve stresses that
could damage the structure.
A single conveyor belt flight runs
along the top chord of the trusses the
length of the mobile conveyor. The
belt drive typically is located at the
end of the machine where it is closest
to the electrical power.
The mobile conveyor tripper travels
along the top chords of the mobile
stacking conveyor. The tripper “trips”
ore onto the cross conveyor belt and
discharges the material onto the
stack. The cross conveyor is long
enough so the pile can be built to the
design height while keeping the
crawler track back from the advancing
toe of the pad.
The mobile conveyor’s control system
combines human interface and
automatic controls for various
functions. The operator can override
the automatic controls if needed as
well as control the upstream
equipment. Manual controls such as
the tripper speed and cross conveyor
position can be used to build the
smoothest possible leach pad.
Automatic controls generally monitor
frame alignment, leveling, and other
conveyors upstream for the operator.
The controls system is unique to the
equipment and allows the MSC to
handle material while it moves. It is
important to point out that ore
handling does not stop when the
tripper or the entire machine moves.
Waste Stacking System
This is a very efficient and costeffective method of stacking waste
ore. The Mobile Stacking System
advance stacks in a radial mode, as
indicated by the arcing sweeps. Once
a lift has been completed, additional
lifts can be stacked on top through
the use of elevating conveyors. By
stacking in lifts, several years of waste
material can be stacked on a small
footprint, thereby reducing the
environmental impact.
A stacker, such as a Mobile Bridge
Boom Stacker, can be added to the
Mobile Stacking System to increase
the distance between the edge of the
pile and the stacking system,
depending on geotechnical
requirements of the stacking plan.
The addition of a stacker can also
increase the flexibility of the stacking
system when filling complex valleys.
8
Hydrate classification & slurry pumping
Hydrocyclones
Hydrocyclones are used in many
alumina refineries to enhance
classification efficiency.
A partial list of applications includes
• Bauxite grinding
• Bauxite refinement
• Sands separations from red muds
• Sand washing,
• Hydrate classification
• Product size control
• Seed size control
• Hydrate thickening
• Deliquoring
• Agglomeration
• Preferential separation/reduction
of oxalates
• Spent liquor solids recovery
• Cooling tower water clean-up
• Lime slurry degritting
The most common applications are
sands separation from red muds and
the various duties in the hydrate
classification and debottlenecking area.
The versatility of hydrocyclones
suggests they may be suitable
problem solvers in many applications
and this must be determined by a
step-by-step evaluation. Solutions are
tailored to meet the individual plant
and operating conditions with
hydrocyclones which are a low cost
investment item. High efficiencies and
outstanding flexibility are combined
with simple operation and
maintenance without any special
space or installation requirements.
FLSmidth Krebs is an innovative
hydrocyclone supplier offering
experience and value in proving
benefits, thorough testing, optimum
equipment design, suitable controls,
maintenance friendly, and an
appreciation of the limits of
performance.
KREBS® millMAX™ for the
alumina industry
KREBS® millMAX™ Pumps treat the
cause of pump wear and loss of
efficiency. In most established
millMAX™ installations, wear life of
parts has been even and in the
majority, overall wear life has
generally improved by 100%. The
increase in wear life is achieved
together with a reduction in power
consumption typical in the 10-20% or
lower range.
The reduction in power consumption
can be as a cost saving, or additional
pumping capacity with the same
installed motor.
• Patented design feature to
reduce degradation of solids
• High Chrome Iron Construction
• Reduced energy consumption for
same flow/head
• Longer, more uniform wear life
• Optional driMAX™ slurry
mechanical seal
• High temperature elastomer seals
• Stainless steel fasteners
9
Seed & product hydrate filtration
Seed hydrate filtration
High capacity, large diameter disc
filters
The large diameter, high capacity disc
filter is the state-of-the art filter for
filtration of seed and product hydrate
in the precipitation circuit.
• HiFlow hydraulic design for
highest filtration capacity and
lowest cake moisture
• Reliable cake discharge by
advanced blow back design
• Large diameter discs with 5.5 or
6.0 m diameter
• High speed filter with up to 6.0
rpm disc speed
• Multiple discs with up to 6 discs
per filter
• Multi-channel design providing 40
channels for 40 sectors per disc
• Optimum slurry agitation by discs
running in multiple low volume
troughs
• Special design for quick and
simple disc replacement
• Improved sector and rim fixing
system resulting in proven
long-term mechanical and
operating reliability
• Extended cloth life time due to
modern sector design and
improved cloth cleaning features
Product hydrate filtration
High capacity horizontal pan filters
The high capacity horizontal pan filter
is a highly reliable filter specially
designed for the actual needs in the
alumina industry.
• The filter design envelopes a
modern synthesis of latest
process achievements with
reliable and rugged equipment
design for highest customer
satisfaction
• Advanced filtration rates are
combined with most efficient
counter current washing
technology
• Enhanced product hydrate
characteristics achieved through
heel cake filtration
• Large diameter pan filters with
up to 10 m diameter in successful
conventional (71m²) operation
• Advanced self-control features
• Lowest cake moisture through
using vacuum steam drying
technology
• Special uniform slurry distribution
device resulting in even cake
build-up
• Reliable cake discharge by
wear-resistant discharge scroll
• Highest filter productivity due to
extended operation cycles
• Preventative maintenance
friendly design
10
Gas suspension calcination (GSC)
The gas suspension calciner (GSC) for
alumina was developed by FLSmidth
from 1976 to 1984. The first unit at
Hindalco, India, has now been in
operation since 1986.
Air pollution control
More than 7,500 Air Pollution
Control Installations State-of-the-Art Gas Distribution
using CFD Modelling
The GSC units at Queensland
Alumina in Gladstone, Australia,
shown on the cover page were the
first calciners in the alumina industry
with application of a bag-house for
air pollution control located directly
after the calcination process.
Electrostatic precipitators
for low dust emission
• Minimum spare parts stock
• 65 years of experience
• Emission < 15 mg/Nm³
• High availability
• > 20 years of lifetime
• Low pressure drop
• Back corona eliminated
• Low power consumption
• Multi-level collecting plates
rapping
• Automatic performance
optimization
• Unbreakable discharge
electrodes
This calcination facility comprises 3 x
4500 t/day of GSC units, the world’s
largest calciners producing alumina.
Today, FLSmidth has proven GSC
operation with Heavy Fuel Oil, Natural
Gas and Coal Gas from a gasification
plant.
Electrostatic Precipitator
Fabric Filters
Typical annual calciner availability
exceeds 98% with particulate dust
emission not exceeding 20 mg/Nm3
(dry) exhaust gas.
GSC
Technology
Feature
GSC Customer
Benefits
Operation below
ambient pressure
•Safe on line
maintainability
•Minimum
down time for
maintenance
Calcination in
one furnace pass
only, without recirculation of partly
calcined alumina
•Minimum
mechanical impact
on alumina
•Minimizing particle
breakdown
Four (4) direct heat
recovery stages
Minimum thermal
energy consumption,
CO2-Emission and
heat lost to the
cooling water
Hot stand-by
operation without
alumina production
•Minimum thermal
shock of refractory
•Maximizes service
life of refractory
Fabric filters for cement &
minerals Industry
• Tailor-made to alumina & cement
• Low maintenance costs
• On line maintenance
• High availability
• On line supervision
• Own bag fabrication
• Constant low emission
• Low air consumption
• Star-shaped cages
• “Smart” pulse control
• Down flow between bags
• Low cleaning pressure
11
Alumina handling & storage
in refinery and smelter
Handling of primary alumina,
secondary alumina, crushed
bath, fluoride, calciner dust
and petcoke
• Loading and unloading of trucks,
railcars and ships
• Pneumatic and mechanical
transport
• Screening, Dosing and Blending
• Storage in different silos
• Silo feeding and discharge with
special systems on silo top and
bottom in Anti-Segregation
Design for low separation of
finest particles
• Direct pot feeding systems
Storage
• Mechanical Belt Conveyors for
1,200 t/h from Ship Unloader to
Transfer Towers with Weighing
and Dust Extraction Systems
• Large Capacity Silos up to 85,000
m3 (and more, if required )
• Transfer Towers with Airlift
Systems 600 t/h each for 65 m
vertical transport
• Distribution Airslide Conveyors to
various Storage Silos
• Anti-Segregation Silo Feeding
Systems downstream mechanical
conveyors and Airlift
• Anti-Segregation Silo Reclaim
Systems, designed also to limit
dead stock volumes to smallest
possible extent
• Downstream pneumatic transport
equipment such as Airlift, Dust
Pump or Pressure Vessels with
TURBUFLOW® Pipe
• Tanker and Railcar Loading and
Discharge Stations
FLSmidth’s proprietary Möller
technology
• Pneumatic MÖLLER TURBUFLOW® pressure vessel systems
• High dense phase conveying
• High conveying capacities over
long distances – up to 250 t/h
and more
• First and only 3,000 m direct
conveying project worldwide
(Sumitomo Kashima Steelworks,
Japan)
• Airslide systems for distribution
and storage facilities
• Airlifts for vertical conveying
• MÖLLER dust conveying pumps
(screw conveying)
• Small, medium, and large steel
and concrete silos for short and
long-term storage
• Special silo feeding and discharge
equipment to minimize particle
segregation and to achieve
uniform particle size distribution
for the material passing through
the silos
• Direct pot feeding technology for
alumina smelter plants
TURBUFLOW® features
• High dense phase conveying
• High loading ratio (kg bulk/kg air)
• Very low air/bulk velocity at the
beginning and the end of the
conveying pipe
• Low wear due to very low
velocities
• Very low particle segregation
during conveying of alumina
• No plugging
• Start-up with bulk loaded pipe
• Self-regulating system
12
Expert control system (ECS) & simulation
More than 39 years of process
knowledge and experience
Gain access to FLSmidth’s unparalleled
knowledge and experience with
process control, entailed in our ECS
range of adaptable solutions.
ECS/control center solution
• More than 39 years of process
knowledge and process
experience is unparalleled in the
industry and is a unique support
in our control centre solutions
• SCADA/PLC system with DCS
functionality providing highly
flexible solutions that are
independent from PLC platform
• More than 700 ECS/
ControlCenter solutions
commissioned since our first
computer based Plant Control
and Supervision system was
installed in 1972
ECS/process epert solution
• Our ECS/ProcessExpert
applications have a field proven
track record since 1978 providing
significantly improved process
stability through continuous,
accurate and consistent process
evaluation and control actions
• The ECS/ProcessExpert solution
entails uniform control strategy
improving end-product quality
regardless of individual operators’
skills
•
Improved process stability and
flow providing
• Lower operation costs
• Increased throughput
• Improved temperature control
=> more consistent quality
• Less blockages => less down
time => less wear
• Typical results in the industry,
with variations in production
type, product type, maintenance
level, etc.:
• Production increase: .....3-8%
• Fuel savings: .................2-8%
• Quality improvement:up to 30%
• Decreased standard deviation:
10-20%
Remote services
• Remote Process Troubleshooting
• Remote Process Support
• Remote Software Maintenance
• Remote Engineering
• Remote Optimization
Simulator
• State of the art in computerbased training
• Risk free environment enabling
learning about:
• Processes behaviour
• Control system behaviour
• Provide hands-on experience with
a true-to-live plant
• Enable faster start-up and
productivity in new plants
• Built-in operator evaluation and
certification
13
Quality control by x-ray
(QCX) & RoboLab solutions
First automated quality control
solution in operation in 1971.
FLSmidth has a unique experience in
the quality control market, with a
proven track record of more than 500
automated laboratories commissioned
in the industry.
QCX/RoboLab
• FLSmidth’s Quality Control
Solutions are supported by more
than 36 years of process
knowledge and process
experience
• The unique QCX/RoboLab
solution’s ability to operate 24/7
at constant, high pace and high
accuracy will provide an improved
and precise overview on
production
• Thus achieving significantly
reduced variation in product
quality
• An automated sampling process
will procure correct representative
sampling at the process and at
the specified locations supported
by fast delivery of samples to the
lab
• Improved health and safety
environment by releasing
operators from heavy lifting and
working in a dusty and noisy
environment
• The QCX/RoboLab solutions
range from sampling to analysing
in the Bayer Process as well as in
the Refinery and Smelter Process
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Our robotic cell structure clearly
defines each cell’s functionality
providing a high degree of
flexibility in design, layout and
development of the laboratory
The flexible concept allows for
partial and step-by-step
automation, e.g. step one; focus
on quality and/or health and
safety issues; expanding to fully
automated operation at a later
stage
Centralized laboratory or
dedicated in-situ lab
• FLSmidth’s alternative to the
centralized laboratory is an
automated container laboratory
solution, transportable to any
location, close to the process
requiring time critical analysis
• Fully self-contained solution with
electrical and compressed air
distribution, de-dusting ensures
the optimum environment for
high quality analysis
• The typical configuration includes
the following analysis equipment:
• Sample milling machine
PAL-MIL R
• Sample handling robot
• Optical emission Spectrometer
SPECTROLAB
• QCX metal control system
14
Refinery capabilities
15
Smelter capabilities
trademark of FLSmidth A/S. This brochure makes no offers, representations or warranties (express or implied), and information and data contained in this brochure are
for general reference only and may change at any time.
Australia
FLSmidth Pty Ltd
Tel: +61 3 8336 1233
Email: [email protected]
Germany
FLSmidth Wiesbaden GmbH
Tel: +49 (0) 6123 / 975 300
Email: [email protected]
USA
FLSmidth Salt Lake City, Inc.
Tel: +1 801 871 7000
Email: [email protected]
Russia
FLSmidth Russia CIS
Tel: +7 495 641 2778
Email: [email protected]
Brazil
FLSmidth Ltda.
Tel: +55 15 3416 7400
Email: [email protected]
India
FLSmidth Private Ltd
Tel: +91 44 4748 1000
Email: [email protected]
USA
FLSmidth Krebs Inc.
Tel: +1 520 744 8200
Email: [email protected]
Denmark
FLSmidth A/S
Tel: +45 36 18 10 00
Email: [email protected]
www.flsmidth.com
Rev. 10/19//2011 al-us
Copyright © 2011 FLSmidth A/S. ALL RIGHTS RESERVED. RTA settler-washer technology presented with authorization of Rio Tinto Alcan. FLSmidth is a (registered)