AECH 1103 | Topic 6.1 Metal Industry: Iron and Steel

• Ferrous Metals

• Non-ferrous Metals

• Superalloys

These are the three types of metals.

Ferrous Metals

These metals are those based on iron.

• Steels

• Cast irons

These are the types of ferrous metals.

Non-ferrous Metals

These metals refer to all other metals.

• Aluminum

• Magnesium

• Copper

• Nickel

• Titanium

These are five examples of non-ferrous metals.

ore

Fill in the blank.

Metals come from rocks in the ground called ________.

Hematite

This is the main iron ore.

Iron Making

This production process occurs when iron is reduced from its ores.

Steel Making

This production process occurs when iron is refined to obtain desired purity and composition (alloying).

Steel

It is an iron-carbon alloy containing from 0.02% to 2.1% carbon.

Cast Iron

It is an iron-carbon alloy containing from 2.1% to about 4% or 5% carbon.

Steels, cast irons, carbon

Fill in the blanks.

__________ and _____________ can also contain other alloying elements besides __________.

Iron ore

It is a rock that contains iron combined with oxygen.

Hematite (Fe₂O₃)

It is the principal ore used in the production of iron and steel.

magnetite (Fe₃O₄), siderite (FeCO₃), limonite (Fe₂O₃-xH₂O)

Fill in the blanks.

Other iron ores include _____________, ____________, and _____________.

50%, 70%, grade, 70%

Fill in the blanks.

Iron ores contain from ______ to around _______ iron, depending on __________ (hematite is almost ______ iron).

Scrap iron, steel

Fill in the blanks.

____________ and ___________ are also widely used today as raw materials in iron and steel making.

Coke

It is made from coal; once minced, the coal is crushed and washed.

Coke

This supplies heat for chemical reactions and produces carbon monoxide (CO) to reduce iron ore.

Hot gases

• CO

• H2

• CO2

• H2O

• N2

• O2

These are used to burn coke.

limestone, dolomite

These are examples of fluxes.

Flux

It is a term for minerals used to collect impurities during iron and steel making.

flux, elements, steelmaking, slag

Fill in the blanks.

The _________ causes a chemical reaction, and ___________ not needed for ___________ join to form _______.

Blast Furnace

It is a refractory-lined chamber with a diameter of about 9 to 11m at its widest and a height of 40m.

1. Charging the Blast Furnace

• The raw iron is blended with other ore from the top of blast furnace

• Very hot air is blown through nozzles

• Oxygen reacts with the carbon dioxide and pure iron

2. Separating the Iron from the Slag

• The melted iron sinks to the bottom of the furnace

• The limestone combines with the rock and other impurities in the ore to form a slag, which is lighter than the iron and floats on top

• Drawn off the iron and slag separately from the bottom

• Casting iron into an alloy called pigs iron

3. Treating the Gases

• Hot gases produced in the chemical reactions rise to the top of the furnace

• Gas treating plant to clean the gas

• Carbon monoxide is useful for chemical reactions

These are the three steps in the blast furnace operation.

Iron ore (haematite), coke, limestone

Fill in the blanks.

______________, __________, and ______________ are placed in the top of the blast furnace.

coke, carbon monoxide, fuel

Fill in the blanks.

The ________ is used to make the reducing agent _____________ and as a _________ to heat the furnace.

Hot air

Fill in the blanks.

____________ is blasted into the furnace.

iron ore, iron

carbon, iron

Fill in the blanks.

In the blast furnace, _____________ is reduced to __________.

This reaction is possible because ___________ is above ___________ in the reactivity series.

Oxygen, carbon, coke

exothermic

Fill in the blanks.

_____________ in the air reacts with ____________ in the _________.

The reaction is highly ______________.

carbon dioxide, carbon, carbon monoxide

Fill in the blanks.

The _______________ produced reacts with more ____________ to produce _______________.

carbon monoxide, iron oxide

reduction, oxygen

Fill in the blanks.

The ______________ reduces the ________________.

______________ involves removing _____________.

silica, iron ore, lime, thermal decomposition, limestone

calcium silicate (slag), molten slag

Fill in the blanks.

______________ in the _____________ is removed by reacting with _________ produced from the ______________ of _______________.

______________ is produced, ______________ is run off and cooled.

molten iron, furnace, cast

Fill in the blanks.

_____________ runs to the bottom of the ___________; it is taken out (_________) at regular intervals.

Cast Iron

It is cheap and easily molded; it is used for drainpipes and engine blocks.

rail cars, molten iron

Fill in the blanks.

Special __________ bring the _________ away.

Pig Iron

This is the cooled liquid iron that typically flows into a channel and indentations in a bed of sand.

Pig Iron

It is raw iron in an ingot form; the name is derived from the time when the iron ran into molds and the row of molds was said to resemble a litter of suckling pigs, so the single ingots were referred to as pigs.

hard, brittle, iron, carbon, manganese, sulphur, phosphorus, silicon

Fill in the blanks.

Pig iron is a ________ but ________ mix of ________ (90% or more) and ________ (typically 4-5%), ________, ________, ________, and ________ (roughly 3% in total).

• 2 tons of ore

• 1 ton of coke

• 1/2 ton of limestone

These are the needed materials to create a ton of pig iron.

• fire should consume 5 tons of air

• temperature should reach almost 1600°C at the core of the blast furnace

These are the conditions needed to be met to create a ton of pig iron.

• carbon + oxygen → carbon dioxide

• carbon dioxide + carbon → carbon monoxide

• iron oxide + carbon monoxide → iron + carbon dioxide

These are the reactions taking place in the production of pig iron.

calcium carbonate → calcium oxide + carbon dioxide

This is the thermal decomposition reaction in the production of pig iron.

calcium oxide + silicon dioxide → calcium silicate (slag)

This is the neutralization reaction in the production of pig iron.

carbon, hard, brittle, useless

Fill in the blanks.

Pig iron contains 4-5% ____________ and is so ____________ and ___________ that it is almost _____________.

• Melt it, mix it with slag, and hammer it to eliminate most of the carbon (down to 0.3 percent) and create wrought iron.

• Create steel

This is what can be done in order to make pig iron more useful.

Wrought Iron

It is the stuff a blacksmith works with to create tools, horseshoes, and more.

malleable, bendable, weldable

Fill in the blanks.

When you heat wrought iron, it is ___________, ____________, ___________, and very easy to work with.

Steel

It is an alloy mainly composed of carbon and iron. It has a consistent concentration of carbon throughout (0.5 percent to 1.5 percent).

silica, phosphorus, sulphur

Fill in the blanks.

Impurities like _________, __________, and ____________ weaken steel tremendously, so they must be eliminated.

steel, iron, strength

Fill in the blanks.

The advantage of ________ over ________ is greatly improved __________, so it is used in buildings, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons.

Manganese, Chromium, Tungsten, Vanadium, Nickel

These elements are sometimes added to enhance steel's properties.

Pig Iron: contains more than 2% carbon, brittle in nature and breaks easily, cannot be welded, cannot be rolled into sheets, cannot absorb shock

Steel: contains less than 2% carbon, tough in nature, can be welded, can be rolled into sheets (malleable), can absorb shock

Give five characteristics of pig iron vs. steel.

Iron Making

This needs raw inputs of iron ore, coke, and lime that are melted in a blast furnace.

Steel Making

This needs molten steel from the basic oxygen furnace (BOF) or electric furnace routes that are treated to adjust steel composition.

Steel Forming

This is when steel is formed into shapes by hot rolling and different shaping techniques.

1. Iron Making

2. Steel Making

3. Steel Forming

4. Manufacturing

5. Fabrication

6. Finishing

This is the production process of steel.

Basic Oxygen Furnace

This accounts for 70% of steel production in the U.S.

Bessemer Converter

Fill in the blank.

A Basic Oxygen Furnace (BOF) is an adaptation of the ______________.

Bessemer Process

This uses air blown up through the molten pig iron to burn off impurities.

oxygen

Fill in the blank.

Basic Oxygen Furnace (BOF) uses pure ___________.

5m (16ft), 150, 200

Fill in the blanks.

A typical BOF vessel is ______ inside diameter and can process _____ to ______ tons per heat.

45

Fill in the blanks.

The entire cycle time (tap-to-tap time) of a basic oxygen furnace (BOF) takes _____ minutes.

(1) charging of scrap and (2) pig iron

(3) blowing

(4) tapping the molten steel

(5) pouring off the slag

This is the Basic Oxygen Furnace (BOF) sequence.

Electric Arc Furnace

This accounts for 30% of steel production in U.S.

scrap iron, scrap steel

These are the primary raw materials of an Electric Arc Furnace.

25, 100

Fill in the blanks.

An electric arc furnace's capacities commonly range between _____ and ______ tons per heat.

two, four

Fill in the blanks.

An electric arc furnace's complete melting requires about ____ hours; tap-to-tap time is ____ hours.

alloy steels, tool steels, stainless steels

Fill in the blanks.

An electric arc furnace is usually associated with production of __________, ____________, and ____________.

quality, higher

Fill in the blanks.

An electric arc furnace is noted for better _________ steel but __________ cost per ton compared to BOF (Basic Oxygen Furnace).

thermal, electric, smelt

Fill in the blanks.

An electrical furnace in which the ____________ effect of an _____________ arc is used to _________ metals and other materials.

heating, direct, indirect, submerged

Fill in the blanks.

Arc furnaces are classified according to their method of ___________ as ___________ and ___________ furnaces and furnaces with a ___________ arc.

solidified, cast ingots, continuous casting

Fill in the blanks.

Steels produced by BOF or electric furnace are ___________ by subsequent processing either as _____________ or by _______________.

1. Casting of ingots - a discrete production process

2. Continuous casting - a semi-continuous process

These are the casting processes in steelmaking.

Steel Ingots

These are discrete castings weighing from less than one ton up to 300 tons (entire heat).

carbon iron, top, bottom, solid casting

Fill in the blanks.

The molds used in the casting of ingots are made of high __________, tapered at _____ or _________ for the removal of __________.

stool

Fill in the blanks.

The mold used in the casting of ingots is placed on a platform called a ___________.

mold, lifted, casting, stool

Fill in the blanks.

In the casting of ingots, after solidification the ______ is _________, leaving the __________ on the _________.

Continuous Casting

This is widely applied in aluminum and copper production, but its most noteworthy application is in steel-making.

ingot casting, discrete

Fill in the blanks.

Dramatic productivity increases over _____________, which is a __________ process.

10, 12

Fill in the blanks.

For ingot casting, ______-_____ hr may be required for casting to solidify.

Continuous casting, solidification, magnitude

Fill in the blanks.

_______________ reduces ____________ time by an order of ____________.