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Guidelines for Selecting Pellet Plant TechnologyI. Cameron, M. Huerta, J. BolenM. Okrutny, K. O’Leary

AusIMM, Iron Ore Conference , Perth WA  |  13‐15 July 2015

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Introduction• The availability of lump ore and sinter fines is declining; lower grade

iron ore resources must be finely ground to upgrade Fe content to acceptable levels.

• Eventually, new investments in pelletizing capacity are required to bring Fe concentrates into the steelmaking value chain.

• The straight grate (SG) and grate kiln (GK) are the only two commercially proven processes.

• Hatch compared both technologies to help investors better understand how best to pelletize concentrates.

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Contents• Iron Ore Pelletizing Technologies

• Plant Capacity

• Fuel Options and Energy Consumption

• Pellet Product Quality

• Capex and Opex

• Environmental Performance

• Summary

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The Growth of Iron Ore Pelletizing

• Iron ore pelletizing has grown since its origins in 1950’s and accelerated in recent times.

• With depletion of high quality DSOs and sinter fines, global pellet feed production will substantially increase.

• Pelletizing capacity will continue to grow to supply direct reduced iron plants and blast furnaces.

• Usage of pellet feed at sinter plants will increase.

Regional growth since 1950

0

100

200

300

400

500

1949 1968 1975 1982 1990 1998 2004 2010

World Pelletizing Ca

pacity (M

tpa)

Year

ChinaMiddle EastRest of Asia / AustraliaEuropeCISSouth AmericaNorth America

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Straight Grate (SG) and Grate Kiln (GK)

The Straight Grate (SG) pelletizing process

The Grate Kiln (GK) pelletizing process

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New Emerging Technology: Circular Pelletizing Technology (CPT)

Primetals Technologies’ Circular Pelletizing Technology (CPT)

• Alternative to SG and GK.

• Essentially a SG indurationfurnace arranged in a circle to reduce the plant footprint.

• Current plant sizes on offer -0.6 to 3.0 Mtpa.

• First plant under construction in India.

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Iron Ore Mineral Pelletized

• The SG technology is proven for magnetite, hematite and mixed ores.

• The GK is proven for magnetite ores and mixtures of magnetite and hematite; less experience with hematite ores than the SG.

Pelletizing capacity by iron ore mineral

0

50

100

150

200

250

300

SG GK

World Pelletizing Ca

pacity 

(Mtpa)

Other OresHematiteMagnetite + HematiteMagnetite

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Pellet Plant Capacity Increase Since 1960

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

1960 1970 1980 1990 2000 2010 2020

Annu

al Cap

acity

 of Ind

ividua

lPe

llet Lines (M

tpa)

Year

CarbonAddition

AutomationSystems

DeepBed

Double Deck Roller Screen

Hyper‐Activation

High Pressure Grinding Rolls

Mathematical Models

AdvancedProcessControl

ExpertSystems

CoolerRecoup

ReducedAir

Leakage

Fans withVariable Frequency Drives

Hearth Layer Bin Separation

SG ImprovementsGK ImprovementsSG/GK Improvements

Coal Fired Kiln

RollerScreen

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Fuel OptionsAbility of SG and GK to use various fuels

Fuel SG GK

Gaseous Fuels

Liquid Fuels

Solid Fuels, such as coal

Solid Carbon Addition to HematiteConcentrate Limited

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Energy ConsumptionThermal energy consumption for selected pellet plants

Electricity consumption for process fans

0 200 400 600 800 1000 1200

Magnetite

Mag ‐ Hem

Magnetite

Mag ‐ Hem

Mag ‐ Hem

Magnetite

Magnetite

Thermal Energy Consumption (MJ/t pellet)

GKSG Technology Typical

(kWh/t)

Lowest Reported(kWh/t)

SG 20 - 25 13

GK 15 - 20 12

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Pellet Product Quality• Both SG and GK produce quality fired pellets for BF and DR applications.

• Fired pellet quality depends on ore type, end user demands, type and quality of fluxes and binders, balling technology, screening equipment, etc.

• The GK produces fired pellets with more uniform physical strength due to the nature of material flow in the rotary kiln that exposes all green pellets to the peak firing temperature.

• The SG generates less fines due to the absence of transfer points and little relative movement/abrasion between pellets and furnace parts.

• Both SG and GK report experience with organic binders; more data is needed to fully understand how best to use organic binder and produce top quality pellets.

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Capex and Opex Comparison

Capex Comparison – SG and GK Opex Comparison – SG and GK

0

20

40

60

80

100

Straight Grate Grate Kiln

Relativ

e Ca

pital Cost

Cost Items SG GK

Iron Ore Concentrate similar similar

Additives/Binder similar similar

Fuel ▼ ▲

Electricity ▲ ▼

Water similar similar

Refractory ▼ ▲

Other Consumables similar similar

Labour similar similar

Maintenance ▼ ▲

Overall similar similar

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Environmental Performance• Air pollutants of concern are dust, SOx, NOx and greenhouse gases (GHG).

• Both technologies use ESPs or bag houses for dust control.

• Newer plants are considering de-S equipment to reduce emissions.

• The SG can utilize ultra low NOx burners in a separate combustion chamber with controlled atmosphere; this approach is not possible in the GK.

• Low NOx burners can be used in the GK, but the ultra low levels projected for the SG are probably not possible for the GK.

• GHG production, particularly CO2 is directly related to the type and amount of fossil fuel combusted and the calcination of fluxes.

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Overall Comparison – SG and GKSG GK Remarks

1) Iron Ore Minerala) Hematite

yeslimited

useb) Magnetite yes yesc) Hematite/Magnetite Mixture yes yes

2) Unit Capacitya) 3-7 Mtpa yes yesb) 7-9 Mtpa yes no

3) Fuel Typea) Natural Gas yes yesb) Fuel Oil yes yesc) Pulverized Coal no yesd) Carbon Addition to Hematite Ore Mix

highamount

limiteduse

Legend: Competitive advantageNo advantage/disadvantageDisadvantageTechnical constraint

Variable

GK is best suited for magnetite and magnetite/hematite mixtures while SG is suitable for all minerals.

GK has not demonstrated unit capacities beyond 7.0 Mtpy.

SG has not demonstrated operation with pulverized coal while GK can operate will all fuels.SG can operate with high amounts of carbon additions to hematite ore mixes whereas the use of GK for this application is limited.

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Overall Comparison – SG and GKSG GK Remarks

4) Thermal Energy Consumption slightly lower

slightly higher

Slight advantage for SG.

5) Electrical Energy Consumption higher lower Advantage for GK due to smaller process fans.6) Product Quality slightly

lowerslightly higher

GK provides better fired pellet temperature uniformity.

7) Fines Generationless fines

more fines

Advantage to SG due to lack of transfer points.

8) Organic Binder Use yes limiteduse

In general, advantage to SG, although some have reported advantage to GK.

9) Capex slightly higher

slightly lower

Slight advantage for GK in process fan cost, no hearth layer return system and less building costs.

10) Opex similar similar Site specific.11) Environmental Performance slightly

higherslightly lower

More potential to reduce NOx for the SG in a separate combustion chamber, otherwise no obvious advantage.

Legend: Competitive advantageNo advantage/disadvantageDisadvantageTechnical constraint

Variable

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Acknowledgements• The authors are pleased to acknowledge the following contributors

for their valuable input:– David Tucker

– Jose Murilo Mourão

– Miguel Sabanero

– Urano Medeiros

– Kelly Scott

– Mike Walsh

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For more information, please visit www.hatch.ca

Thank You

Ian CameronSenior Director – Iron & SteelPhone +1-905-403-4052icameron@hatch.ca