ironmakingiTmk3®

forSolutions Steelmakers

www.midrex.com

Flue Gas

Offgas Treatment

CombustionAir

Burner Fuel

HeatRecovery

AirIron

OxideReductant

(coal)

Mixing Agglomeration Drying

Rotary Hearth Furnace

Separation

Iron Nuggets

Slag

ITmk3 (pronounced “eye tee mark three”) stands for “ironmaking technology mark three.” It represents the third generation of ironmaking,

with the first generation being the blast furnace and the second generation gas-based direct reduction. ITmk3 uses iron ore fines and

non-coking coal to produce a premium quality pig iron product, thus avoiding the need for oxide pellets or sinter and coke. It is elegantly

simple, performing reduction and melting functions within one vessel, the rotary hearth furnace (RHF).

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iTmk3®: nEXT gEnEraTion ironmaking Process / TechnologyThe process begins with mixing of iron ore concentrate and

fine coal. The mixture is pelletized, dried, and fed to the RHF.

The pellets are reduced and melted within approximately

ten minutes, then discharged. The final step is separation

of iron nuggets and slag. During reduction, volatiles from

the coal and carbon monoxide (CO), produced from

reduction, evolve into the gas space above the hearth

and are combusted with air. The heat thus generated, plus

heat from the burners, provides the energy required for

reduction and melting. The offgas from the RHF is fully

combusted, but does contain considerable sensible heat.

The offgas first passes through a heat recovery system

to preheat combustion air, and then it goes to a gas

cleaning system to remove particulates before being

discharged to the atmosphere.

Cross Section View Plan View

ITmk3® Process Flowsheet

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –– – – – – –

ITmk3® RHF Reduction Technology

Offgas

Preheating Reduction Melting Cooling Discharging

Slag

Nugget

Feeder

Hearth

BurnerFuelAir

Heat

CO

Heat

2CO + O2 g2CO2

Post Combustion

Cooling

The pellets are heated up to 1350-1450 (°C)

iron nuggeTsITmk3 Nuggets are an ideal steelmaking feed material. They are essentially

all iron and carbon, with almost no gangue (slag) and low levels of metal

residuals. The nuggets are a premium quality pig iron product with superior

shipping and handling characteristics. They can be shipped in bulk inland

or oceangoing vessels, railcars or trucks, and stored outside with no special

precautions. They can be handled as a bulk commodity using conventional

magnets, conveyors, bucket loaders, clams, and shovels. Charging to an

EAF, BOF, or foundry furnace can be batch or continuous. In the EAF, ITmk3

Nuggets provide an excellent source of low copper feedstock with consistent

chemistry and physical characteristics. They can reduce charging time,

increase meltshop productivity, and reduce energy consumption.

iTmk3 nuggets Typical Characteristics

Metallic Iron Content 96 – 97%

Carbon 2.5 – 3.0%

Sulfur 0.05 - 0.07%

Size 5 – 25 mm

ITmk3® Nuggets

ironmakingITmk3 is an ideal way for iron ore mining companies to process

either magnetite or hematite and supply a premium quality

pig iron product to the steelmaking industry. Plants can be

located at mine sites or in steelmaking facilities. ITmk3 enables

mining companies to produce a value-added product and

steelmakers to obtain a premium quality feedstock for EAF or BOF

use. Plants are under construction and development worldwide.

Since the process performs both reduction and separation of

metal from slag, it effectively concentrates the iron ore. This

opens the possibility of utilizing lower grade iron oxide, such as

very fine tailings from beneficiation plants. ITmk3 is very flexible

regarding carbon sources; the process can use coal, petroleum

coke or other forms of solid reductants.

iTmk3 Process options and Flexibility

Feed Material Iron Ore Concentrate

Reductant Non-coking Coal

RHF Fuel Natural Gas

Applications Mine Site or Steel Mill

Iron Products Iron Nuggets

Iron Product Use EAF or BOF

Single Module 500,000Plant Capacity (tpy)

The rhF concePTITmk3 evolved from the FASTMET® Process, developed by Midrex Technologies and Kobe Steel, Midrex’s parent company. Both

FASTMET and ITmk3 use an RHF to reduce pellets or briquettes made from iron oxide fines and coal.

The hearth is essentially a large turntable that rotates within a toroidal enclosure. The feed pellets (composite agglomerates

made from iron oxide fines and a carbon source such as coal, charcoal, or other carbon-bearing materials) are charged to the

hearth, one to two layers deep, and as they move on the hearth, are heated by burners firing above the hearth and combustion

of gases liberated from the pellets. One revolution of the hearth takes approximately ten minutes. In FASTMET, the product is

direct reduced iron, but in ITmk3, the pellets are melted in the last zone of the hearth to produce a premium quality pig iron

product with a slag by-product.

mIdRex® Rotary Hearth Furnace (RHF) details

Solids Flow

Gas F

lowGas Flow

Solids Flow

Rotat

ion

Gas Flow

Solids Flow

Gas F

low

Gas Flow

Solids Flow

Rotat

ion

Gas Flow

FeederDischarger

WaterSeal

RailWheel

Assembly

Burner

HearthHearth

Typical iTmk3 input Characteristics

Preferred

Iron Ore Feed (Pellet Feed Grade)

Total Iron >60%

SiO2

<8%

Coal

Volatiles <30%

Ash/Fixed C <0.25

environmenTal comPaTibiliTy Environmental issues are a major concern of today’s steel industry. Gaseous

emissions, including SOx, NOx, CO2 and PM10 are being carefully scrutinized

by government agencies and others. ITmk3 has much lower levels of these

pollutants than does the blast furnace.

raw maTerial ParameTers For ITmk3, the feed material is typically iron ore concentrate with the iron

content 60 percent or higher for efficient performance. The figures in the table

to the right reflect general characteristics for best performance. Materials

not meeting these characteristics may be acceptable, depending on economics.

oPeraTing ParameTers While operating parameters will vary depending on the specifics

of the project, the table below should be indicative of performance

for a new installation.

iTmk3 Specific Consumption Figures Per Ton of nuggets

Iron-bearing Feed (t) 1.5

Coal (t) 0.5

Natural Gas Burner Fuel (GJ) 4.6

Electricity (kWh) 200

Water (m3) 2.0

Air (m3) 85

Nitrogen (m3) 12

Direct Labor (personnel) 50 total

Maintenance ($) 5

Other ($) 15

2725 Water Ridge ParkwaySuite 100 Charlotte, NC 28217 USA

704.373.1600

www.midrex.com

t e c h n o l o g i e S , i n c .

why iTmk3®?ITmk3 has a number of advantages for ironmaking. It uses iron

ore fines, either magnetite or hematite, and non-coking coal.

It can be used to produce a high quality pig iron from lower-

grade iron ores, and thus is ideal for adding value to marginal

iron ore reserves. There is no hot metal handling required and

solid pig iron is produced in one step. The plant is easy to

start up and shut down and safe to operate. ITmk3 provides a

means to produce a premium quality pig iron product to feed

EAFs and BOFs. ITmk3 Nuggets have high iron and moderate

carbon content with almost no slag and are easy to handle,

store and continuously charge. The melting characteristics are

excellent. Their use along with scrap enables mini-mills to

produce premium steel grades with low residuals.

ITmk3 typically uses iron ore fines and non-coking coal, thus

avoiding the need for iron oxide pellets or sinter and metal-

lurgical coal. Owners of small mines can extend the lives of

their properties and add value to lower-grade ore resources.

Steelmakers can either purchase ITmk3 nuggets or invest in

production facilities in return for guaranteed product offtake.

ITmk3 has environmental benefits, including considerably

lower emissions of CO2, SO2, NOx and other constituents than

blast furnaces, and avoids the environmental problems of coke

ovens and sinter plants.

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