an
Clogrennane Lime – Producing
Essential Chemical
Clogrennane Lime – Producing
Dark Blue: Pantone 289
Light Blue: Pantone 646
Lime is a vital chemical
Why is the lime mixed with water?
Protecting the environment
Lime is one of the most important chemicals and has been
Dark Blue: Pantone 289
Pantone
646 world from early times. In this
used by people Light
allBlue:
over
the
lesson we look at the chemistry of lime, how it is manufactured
and some of its many uses.
Quicklime is a caustic chemical which burns flesh. Many farm workers
of old discovered this to their horror when quicklime got in their eyes.
Quicklime is still used to destroy carcasses quickly, for example, during a
foot and mouth epidemic. Care must be taken when using lime. It is much
safer in the form of slaked lime. When quicklime is mixed with water it is
turned from quicklime to calcium hydroxide, which is called slaked lime.
This reaction is shown in the following equation
When acid rain falls into lakes it rapidly acidifies them, posing a seriou
threat to all aquatic life. The lakes are crystal clear but dead. This can b
remedied by regular application of lime to the lake which neutralises th
acid. In places like Sweden the lakes are often inaccessible so helicopte
are used to spread the lime
Lime is a vital chemical
Why is the lime mixed with water?
CaO + H2O = Ca(OH)2
lime
used for? Quicklime is a caustic chemical which burns flesh. Many farm workers
Lime is one of the most important chemicalsWhat
and is
has
been
of old discovered this to their horror when quicklime got in their eyes.
Limetimes.
is used extensively
such as steel
used by people all over the world from early
In this in many industrial processes
stillnow
used
manufacturing, mining, ceramics andQuicklime
glass-making.isWe
look to
at destroy carcasses quickly, for example, during a
some
of its uses in building, agriculture,
environmental
protection,
the Care must be taken when using lime. It is much
lesson
we
look
at
the
chemistry
of
lime,
how
it
is
manufactured
foot and mouth epidemic.
Fig.1 The Clogrennane Plant
manufacturing of iron and the production of magnesium oxide from
safer in the form of slaked lime. When quicklime is mixed with water it is
and some of its many uses.
seawater.
How is lime made?
It is remarkable that the process used by the earliest cultures to produce
lime is still in use today. It is easy to make providing you have limestone
and a hot fire. If you get a really strong fire going on limestone (calcium
carbonate) and let it burn overnight, lime will be formed under it. This lime
shows as a white patch. The equation for its formation is
CaCO3 = CaO + CO2
The limestone has been converted to lime (calcium oxide) and carbon
dioxide. Calcium oxide is also known as quicklime.
Building uses
turned from quicklime to calcium hydroxide, which is called slaked lime.
This reaction is shown in the following equation
Fig.3 Spreading of lime on a lake
Lime Mortar is a mixture of lime and sand used to bed stones in walls. Over CaO + H O = Ca(OH)
2
2
time lime mortar reacts with carbon dioxide to form calcium carbonate
Industrial production of iron
which hardens to hold the stones in place. The sand helps bind the
calcium carbonate and also allows air and carbon dioxide into the mixture.
Limestone is used in the production of iron. It is added to the smelt
In effect, the slaked lime has been converted back to limestone.
as one of three layers - iron ore, limestone, and coke. The limeston
decomposes and forms CO2.
Ca(OH)2 + CO2 = CaCO3 + H2O
CO2 as steel
CaCO3 = CaO +
Lime is used extensively in many industrial processes
such
What is lime used for?
The place in which limestone is burned
manufacturing, mining, ceramics
glass-making.
now
lookreduces
at the iro
Some ofand
this CO
is reduced by the We
coke to
CO which
2
Romans invented concrete
is called a limekiln. Old limekilns are
to iron. The CaO
reacts with the SiO
(sand) in the ore
2
some of its uses in building,oxide
agriculture,
environmental
protection,
theto form sla
found all over Ireland because lime
We know that mortar was used by the Romans. Concrete is simply mortar
Fig.1
The
Clogrennane
Plant
was essential for many uses. It could
+ SiO2 = CaSiO
manufacturing
of iron
magnesium
oxide
from
3
with stones in it and it was used by the
Romans to fill the huge
spacesand the production ofCaO
be easily made, providing there was
behind facing stone blocks. It would have
been impossible for them to
The iron sinks to the bottom and so does the slag but the slag floats o
seawater.
a supply of limestone in the locality.
build
structures
such
as
the
Pont
du
Gard
using
all
cut
stone.
Lime
was
top of the iron as it is less dense. The slag is tapped off first followed b
Lumps of limestone were piled on top
precious and mixing stones in with the sand and lime made it go a lot
the iron. The slag is used as road metal, fertiliser and even insulation
of a fire. The temperature had to reach
further. They discovered that by mixing broken tiles in with the lime and
houses when treated appropriately.
between 900 and 1100°C and the kiln
It
is
remarkable
that
the
process
used
by
the
earliest
cultures
to
produce
stones,
the
concrete
hardened
faster
and
even
hardened
underwater.
would be left to burn for a week or
This of
course
made it possible to build in previously unusable areas and
lime
still that
in use
have
limestone
more.
Thisis
means
it wastoday.
a batch It is easy to make providing you
Production of magnesium oxide
places.
process. The heating of limestone to
and a hot fire. If you get a really strong fire going on limestone (calcium
Lime Mortar is a mixture of limeAnother
and sand
used to bed stones in walls. Over
produce calcium oxide is known as
major industrial process that involves the use of limeston
Whitewash is a mixture of lime and water and, sometimes, other additives
carbonate)
it burn
calcination.
Modernand
kilnslet
operate
a overnight, lime will be formed under it. This lime
time
mortar
dioxideof to
form calcium
is the manufacture
magnesium
oxide fromcarbonate
sea water. It is carrie
such as chalk. It is a cheap and effective
way lime
of keeping
housesreacts
looking with carbon
continuous
Limestone
is fed The
out by Premier
PericlaseThe
in Drogheda,
Co. Louth.
A sister
showsprocess.
as a white
patch.
equation
its formation good.
is It also has antiseptic properties. Hence
Fig.2
The kiln at for
Clogrennane
whichwhitewashing
hardensthetoinsides
holdof the stones
in place.
sand helps
bind
thecompany
on a conveyor into the kiln and the
Clogrennane,
Premier
Periclase
also
uses
a
continuous
process whic
animal houses is a common practice on farms.
product (lime) is fed out and stored in bags for sale. The picture shows
calcium
carbonate
and
also
allows
air
and
carbon
dioxide
into
the
mixture.
involves
a
constant
supply
of
raw
materials
and
a
constant
supply of th
CaCO3 =process
CaOused
+ CO
the kiln at Clogrennane Lime Ltd. in Co. Carlow. The
there2is
product.
In effect, the slaked lime has been
converted back to limestone.
outlined in the following diagram.
The limestone has been converted to lime (calcium oxide)
and carbon
Limestone is used to produce calcium hydroxide in the manner describe
Agricultural
uses
CO2 =Seawater
CaCO
+ Hwith
O
Ca(OH)2 + previously.
is 3acidified
2 sulphuric acid and passed through
dioxide. Calcium
oxide is also known as quicklime.
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In the middle ages it was discovered that the addition of lime to soil
tower against a current of air which removes carbon dioxide. This is know
improved drainage and reduced soil acidity. Lime is now widely used as a
as degassing. The calcium hydroxide is then reacted with the degasse
fertiliser. In acid soils the lime neutralises the soil acid which leads to better
The place
in which limestone is burned
water and soluble magnesium ions in the seawater form a precipitate wi
������������������������������������������������������������
grazing. Lime also acts as a soil improver. It causes particles of soil to stick
the hydroxide ions from the calcium hydroxide
�����������������������������������
is called a limekiln. Old limekilns are
together (flocculation) and this makes the spaces between the particles
MgCl2 + Ca(OH)2 = CaCl2 + Mg(OH)2
found all over Ireland because lime
bigger. These bigger spaces improve the drainage and aeration in clay
We know
mortar
was
soils. The use of lime leads to much improved
plantthat
growth.
Calcium
is used by the Romans. Concrete is simply mortar
�������������������������������������������������������������
was essential
for many uses. It could
The magnesium hydroxide is then converted to magnesium oxide b
�������������������������������
also required for the formation of the calcium
of the
lamella
with pectate
stones
inmiddle
it and
it was used
byin the
Romans
to high
fill the
huge
heating
a large
furnace under
pressure.
Thespaces
magnesium oxide
be easily made, providing there was
which cements plant cells together.
into have
a kiln atbeen
very high
temperatures where
it is converted
behind facing stone blocks. Itpassed
would
impossible
for them
to from
a supply of limestone in the locality.
low density state to a more stable, unreactive, high density oxide.
����������������������������������
How is lime made?
Building uses
Romans invented concrete
Lumps of limestone were piled on top
ofmanufacturing
a fire. Theprocess
temperature
had
reach
This
is automated
andtoclosely
controlled by
computer.
between 900 and 1100°C and the kiln
would be left to burn for a week or
more. This means that it was a batch
process. The heating of limestone to
produce calcium oxide is known as
calcination. Modern kilns operate a
continuous process. Limestone is fed
Fig.2 The kiln at Clogrennane
on a conveyor into the kiln and the
product (lime) is fed out and stored in bags for sale. The picture shows
the kiln at Clogrennane Lime Ltd. in Co. Carlow. The process used there is
outlined in the following diagram.
������������������������������������
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�������������������������������
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This manufacturing process is automated and closely controlled by
computer.
build structures such as the Pont du Gard using all cut stone. Lime was
precious and mixing stones in with the sand and lime made it go a lot
further. They discovered that by mixing broken tiles in with the lime and
stones, the concrete hardened faster and even hardened underwater.
This of course made it possible to build in previously unusable areas and
places.
Whitewash is a mixture of lime and water and, sometimes, other additives
such as chalk. It is a cheap and effective way of keeping houses looking
good. It also has antiseptic properties. Hence whitewashing the insides of
animal houses is a common practice on farms.
Agricultural uses
In the middle ages it was discovered that the addition of lime to soil
improved drainage and reduced soil acidity. Lime is now widely used as a
fertiliser. In acid soils the lime neutralises the soil acid which leads to better
grazing. Lime also acts as a soil improver. It causes particles of soil to stick
together (flocculation) and this makes the spaces between the particles
bigger. These bigger spaces improve the drainage and aeration in clay
soils. The use of lime leads to much improved plant growth. Calcium is
also required for the formation of the calcium pectate of the middle lamella
which cements plant cells together.
an
an
Clogrennane Lime – Producing
Essential Chemical
Essential Chemical
Dark Blue: Pantone 289
Light Blue: Pantone 646
Lime is a vital chemical
Why is the lime mixed with water?
Protecting the environment
Lime is one of the most important chemicals and has been
used by people all over the world from early times. In this
lesson we look at the chemistry of lime, how it is manufactured
and some of its many uses.
Quicklime is a caustic chemical which burns flesh. Many farm workers
of old discovered this to their horror when quicklime got in their eyes.
Quicklime is still used to destroy carcasses quickly, for example, during a
foot and mouth epidemic. Care must be taken when using lime. It is much
safer in the form of slaked lime. When quicklime is mixed with water it is
turned from quicklime to calcium hydroxide, which is called slaked lime.
This reaction is shown in the following equation
When acid rain falls into lakes it rapidly acidifies them, posing a seriou
threat to all aquatic life. The lakes are crystal clear but dead. This can b
remedied by regular application of lime to the lake which neutralises th
acid. In places like Sweden the lakes are often inaccessible so helicopte
are used to spread the lime
Protecting the environment
CaO + H2O = Ca(OH)2
When acid rain falls into lakes it rapidly acidifies them, posing
a serious
What is
lime used for?
threat to all aquatic life. The lakes are crystal clear but dead. This can be
Lime is used extensively in many industrial processes such as steel
remedied by regular application of lime to the lake which
neutralises
the ceramics and glass-making. We now look at
manufacturing,
mining,
some
its uses in building, agriculture, environmental protection, the
acid.
In Clogrennane
places like
Sweden the lakes are often inaccessible
soofhelicopters
Fig.1 The
Plant
manufacturing of iron and the production of magnesium oxide from
are used to spread the lime
seawater.
How is lime made?
It is remarkable that the process used by the earliest cultures to produce
lime is still in use today. It is easy to make providing you have limestone
and a hot fire. If you get a really strong fire going on limestone (calcium
carbonate) and let it burn overnight, lime will be formed under it. This lime
shows as a white patch. The equation for its formation is
CaCO3 = CaO + CO2
The limestone has been converted to lime (calcium oxide) and carbon
dioxide. Calcium oxide is also known as quicklime.
Building uses
Lime Mortar is a mixture of lime and sand used to bed stones in walls. Over
Dark Blue: Pantone 289
time lime mortar reacts with carbon dioxide to form
Lightcalcium
Blue: Pantonecarbonate
646
which hardens to hold the stones in place. The sand helps bind the
calcium carbonate and also allows air and carbon dioxide into the mixture.
In effect, the slaked lime has been converted back to limestone.
Fig.3 Spreading of lime on a lake
Specialists in Lime
Production
Industrial
production of iron
Limestone is used in the production of iron. It is added to the smelt
Clogrennane Lime asLtd
isthree
a layers
subsidiary
company
one of
- iron ore, limestone,
and coke. The limeston
decomposes and forms CO .
HO
Ca(OH) + CO = CaCOof+ CRH
plc., with headquarters located in Dublin is
CaCO = CaO + CO
presently the fourth largest
building materials group
Some of this CO is reduced by the coke to CO which reduces the iro
Romans invented concrete
oxide
to iron. The
CaO reacts with
the SiObillion.
(sand) in the ore to form sla
in the world, with annual
sales
exceeding
€12.8
We know that mortar was used by the Romans. Concrete is simply mortar
= CaSiO
+ SiO locations
with stones in it and it was used by the Romans
to fill 60,000
the huge spaces
It has
employees at more thanCaO
2,100
behind facing stone blocks. It would have been impossible for them to
The iron sinks to the bottom and so does the slag but the slag floats o
in all24
countries.
includes
build structures such as the Pont du Gard using
cut stone.
Lime was Product
top of the range
iron as it is less
dense. The cement,
slag is tapped off first followed b
precious and mixing stones in with the sand and lime made it go a lot
the iron. The slag is used as road metal, fertiliser and even insulation
aggregates,
asphalt,
glass
and
lime
products.
further. They discovered that by mixing broken tiles in with the lime and
houses when treated appropriately.
2
2
3
2
2
3
The place in which limestone is burned
is called a limekiln. Old limekilns are
found all over Ireland because lime
was essential for many uses. It could
be easily made, providing there was
a supply of limestone in the locality.
Lumps of limestone were piled on top
of a fire. The temperature had to reach
between 900 and 1100°C and the kiln
stones, the concrete hardened faster and even hardened underwater.
would be left to burn for a week or
This of course made it possible to build in previously unusable areas and
more. This means that it was a batch
Fig.3 Spreading of lime on
a lake
places.
process. The heating of limestone to
produce calcium oxide is known as
Whitewash is a mixture of lime and water and, sometimes, other additives
calcination. Modern kilns operate a
such as chalk. It is a cheap and effective way of keeping houses looking
continuous process. Limestone is fed
Fig.2 The kiln at Clogrennane
good. It also has antiseptic properties. Hence whitewashing the insides of
on a conveyor into the kiln and the
animal houses is a common practice on farms.
product
(lime) is is
fedused
out andin
stored
bags for sale. The
Limestone
theinproduction
of picture
iron. shows
It is added to the smelter
the kiln at Clogrennane Lime Ltd. in Co. Carlow. The process used there is
as
one
of
three
layers
iron
ore,
limestone,
and
coke.
The limestone
outlined in the following diagram.
Industrial production of iron
decomposes and forms CO2.
Agricultural uses
������������������������������������
The iron sinks to the bottom and so does the slag but the slag floats on
����������������������������������
top of the iron as it is less dense. The slag is tapped off first followed by
the
iron. The slag
isisused
as and
road
metal,
fertiliser
and even insulation in
This manufacturing
process
automated
closely
controlled
by
computer. when treated appropriately.
houses
Production of magnesium oxide
Another major industrial process that involves the use of limestone
is the manufacture of magnesium oxide from sea water. It is carried
out by Premier Periclase in Drogheda, Co. Louth. A sister company of
Clogrennane, Premier Periclase also uses a continuous process which
involves a constant supply of raw materials and a constant supply of the
product.
Limestone is used to produce calcium hydroxide in the manner described
previously. Seawater is acidified with sulphuric acid and passed through a
tower against a current of air which removes carbon dioxide. This is known
as degassing. The calcium hydroxide is then reacted with the degassed
water and soluble magnesium ions in the seawater form a precipitate with
the hydroxide ions from the calcium hydroxide
MgCl2 + Ca(OH)2 = CaCl2 + Mg(OH)2
The magnesium hydroxide is then converted to magnesium oxide by
heating in a large furnace under high pressure. The magnesium oxide is
passed into a kiln at very high temperatures where it is converted from a
low density state to a more stable, unreactive, high density oxide.
2
2
3
Clogrennane is a Production
specialistof magnesium
lime producer
oxide
supplying products Another
for various
endprocess
uses
in thethe use of limeston
major industrial
that involves
is the manufacture of magnesium oxide from sea water. It is carrie
industrial, pharmaceutical,
environmental, agricultural
out by Premier Periclase in Drogheda, Co. Louth. A sister company
Clogrennane,
Premierproducts
Periclase also uses
continuous process whic
and construction sectors.
All lime
are asold
involves a constant supply of raw materials and a constant supply of th
product.brand thus reflecting the
under the White Rhino
Limestone is usedof
to produce
calcium hydroxide in the manner describe
strength, purity and uniqueness
the products.
In the middle ages it was discovered that the addition of lime to soil
improved drainage and reduced soil acidity. Lime is now widely used as a
fertiliser. In acid soils the lime neutralises the soil acid which leads to better
������������������������������������������������������������
Limethe
also iron
acts as a soil improver. It causes particles of soil to stick
Some of this CO
is reduced by the coke to CO which grazing.
reduces
�����������������������������������
2
oxide to iron. The CaO reacts with the SiO2 (sand) in the together
ore to (flocculation)
form slag.and this makes the spaces between the particles
bigger. These bigger spaces improve the drainage and aeration in clay
soils. The use of lime leads to much improved plant growth. Calcium is
�������������������������������������������������������������
CaO + SiO2 = CaSiO3
�������������������������������
also required for the formation of the calcium pectate of the middle lamella
which cements plant cells together.
CaCO3 = CaO + CO2
2
2
previously. Seawater is acidified with sulphuric acid and passed through
tower against a current of air which removes carbon dioxide. This is know
The plant, located near
CarlowThetown,
central
toreacted
all with the degasse
as degassing.
calcium is
hydroxide
is then
water and soluble magnesium ions in the seawater form a precipitate wi
its customers throughout
Ireland.
The
adjacent
high
the hydroxide
ions from
the calcium
hydroxide
quality calcium carbonate deposit
raw
material
+ the
Ca(OH)
= CaCl
+ Mg(OH)
MgClis
The magnesium
then converted
to magnesium oxide b
for the White Rhino chemical
lime.hydroxide
It wasisformed
about
heating in a large furnace under high pressure. The magnesium oxide
327 million years ago
in into
the
Lower
Carboniferous
passed
a kiln
at very high
temperatures where it is converted from
low density state to a more stable, unreactive, high density oxide.
(Dinantian) period. Pure deposits with a calcium
carbonate content of (98%) are very rare and are
critical for high quality chemical lime production.
At present extraction rates, this calcium carbonate
deposit will last for at least another 40 years.
2
To find out more about Clogrennane Lime Ltd
visit their website on www.irishlime.com or
www.sciencetechnologyaction.com
Fig.4 Soil Stabilisation using lime
2
2
2
an
Clogrennane Lime – Producing
Essential Chemical
Clogrennane Lime – Producing
Dark Blue: Pantone 289
Light Blue: Pantone 646
Lime is a vital chemical
Why is the lime mixed with water?
Protecting the environment
Lime is one of the most important chemicals and has been
Dark Blue: Pantone 289
Lightall
Blue:over
Pantone 646
used by people
the world from early times. In this
lesson we look at the chemistry of lime, how it is manufactured
and some of its many uses.
Quicklime is a caustic chemical which burns flesh. Many farm workers
of old discovered this to their horror when quicklime got in their eyes.
Quicklime is still used to destroy carcasses quickly, for example, during a
foot and mouth epidemic. Care must be taken when using lime. It is much
safer in the form of slaked lime. When quicklime is mixed with water it is
turned from quicklime to calcium hydroxide, which is called slaked lime.
This reaction is shown in the following equation
When acid rain falls into lakes it rapidly acidifies them, posing a seriou
threat to all aquatic life. The lakes are crystal clear but dead. This can b
remedied by regular application of lime to the lake which neutralises th
acid. In places like Sweden the lakes are often inaccessible so helicopte
are used to spread the lime
Syllabus Reference
CaO + H2O = Ca(OH)2
Activities
What is lime used for?
Organise
a tripsuch
to as
a steel
local chemical plant. Discover if it uses batch or
Lime is used extensively in many industrial
processes
manufacturing, mining, ceramics and
glass-making.process,
We now look
at raw materials are used and what the product
continuous
what
some of its uses in building, agriculture, environmental protection, the
is. Write
balancedoxide
chemical
equations for all the reactions that take place
manufacturing of iron and the production
of magnesium
from
seawater.
during the process.
Leaving Certificate Chemistry:
Unit 4.2 Volumetric Analysis – Acids and Bases
Fig.1 The Clogrennane Plant
Option 1A.1 – Industrial Chemistry
How
is lime
Option
1A.2made?
Case Study – Production of Magnesium Oxide
It is remarkable that the process used by the earliest cultures to produce
What costs are involved? What benefits does the location have – transport,
Building
uses
Option
1B.4
–
Atmospheric
Pollution
– limestone
scrubbing of
waste gases
lime is still in use today. It
is easy to make providing
you have
Fig.3 Spreading of lime on a lake
sources of raw material?
and a hot fire. If you get a really strong fire going on limestone (calcium
Lime Mortar is a mixture of lime and sand used to bed stones in walls. Over
using limestone
carbonate) and let it burn overnight, lime will be formed under it. This lime
shows as a white patch. The equation for its formation is
Junior Certificate
Science:
CaCO = CaO + CO
Section
2C5
–
Effect
rain on
The limestone has been convertedof
to acid
lime (calcium
oxide)limestone
and carbon
3
2
dioxide. Calcium oxide is also known as quicklime.
time lime mortar reacts with carbon dioxide to form calcium carbonate
which hardens to hold the stones in place. The sand helps bind the
calcium carbonate and also allows air and carbon dioxide into the mixture.
In effect, the slaked lime has been converted back to limestone.
Ca(OH)2 + CO2 = CaCO3 + H2O
Industrial production of iron
Limestone is used in the production of iron. It is added to the smelt
as one of three layers - iron ore, limestone, and coke. The limeston
decomposes and forms CO2.
CaCO3 = CaO + CO2
The place in which limestone is burned
Some of this CO2 is reduced by the coke to CO which reduces the iro
Romans invented concrete
is called a limekiln. Old limekilns are
oxide to iron. The CaO reacts with the SiO2 (sand) in the ore to form sla
found all over Ireland because lime
We know that mortar was used by the Romans. Concrete is simply mortar
was essential for many uses. It could
CaO + SiO2 = CaSiO3
with stones in it and it was used by the Romans to fill the huge spaces
be easily made, providing there was
behind facing stone blocks. It would have been impossible for them to
The iron sinks to the bottom and so does the slag but the slag floats o
a supply of limestone in the locality.
build structures such as the Pont du Gard using all cut stone. Lime was
top of the iron as it is less dense. The slag is tapped off first followed b
Lumps of limestone were piled on top
precious and mixing stones in with the sand and lime made it go a lot
the iron. The slag is used as road metal, fertiliser and even insulation
of a fire. The temperature had to reach
further. They discovered that by mixing broken tiles in with the lime and
houses when treated appropriately.
between 900 and 1100°C and the kiln
stones,
the
concrete
hardened
faster
and
even
hardened
underwater.
would be left to burn for a week or
This of course made it possible to build in previously unusable areas and
more. This means that it was a batch
Production of magnesium oxide
places.
process. The heating of limestone to
produce
calcium the
oxidechemistry
is known as of lime production
• Outline
Another major industrial process that involves the use of limeston
Whitewash is a mixture of lime and water and, sometimes, other additives
calcination. Modern kilns operate a
is the manufacture of magnesium oxide from sea water. It is carrie
such as chalk. It is a cheap and effective way of keeping houses looking
continuous process. Limestone is fed
(a)
Limestone
is
sodium
carbonate
T A sisterF company
out by Premier Periclase in Drogheda, Co. Louth.
The kiln at Clogrennane
• Discuss the uses of lime Fig.2
– agricultural,
environmental,
industrial
etc. properties. Hence whitewashing the insides of
good.
It also has antiseptic
on a conveyor into the kiln and the
Clogrennane, Premier Periclase also uses a continuous process whic
animal houses is a common practice on farms.
product (lime) is fed out and stored in bags for sale. The picture shows
a constant
supply of raw materials and a
(b) The process for producing involves
lime from
limestone
TconstantFsupply of th
•kilnOutline
the chemistry
with used
ironthere
andis magnesium
the
at Clogrennane
Lime Ltd. in Co.associated
Carlow. The process
was discovered recently product.
outlinedproduction
in the following diagram.
Limestone is used to produce calcium hydroxide in the manner describe
Agricultural uses
(c) Calcium oxide is called limepreviously. Seawater is acidified with sulphuric acid
T and passed
F through
• Distinguish������������������������������������
between a batch process and a continuous
In theprocess
middle ages it was discovered that the addition of lime to soil
tower against a current of air which removes carbon dioxide. This is know
improved drainage and reduced soil acidity. Lime is now widely used as a
as degassing. The calcium hydroxide is then reacted with the degasse
(d)theSlaked
limeleads
is calcium
T
F
fertiliser. In acid soils the lime neutralises
soil acid which
to better dioxide
water and soluble magnesium ions in the seawater form a precipitate wi
������������������������������������������������������������
grazing. Lime also acts as a soil improver. It causes particles of soil to stick
the hydroxide ions from the calcium hydroxide
�����������������������������������
(e)
lime is
called quicklime
together (flocculation) and this makes
the Slaked
spaces between
thealso
particles
T
F
MgCl2 + Ca(OH)2 = CaCl2 + Mg(OH)2
bigger. These bigger spaces improve the drainage and aeration in clay
soils. The use of lime leads to much (f)
improved
growth.
Calciumthere
is
�������������������������������������������������������������
In a plant
batch
process
is The
a constant
ofis then converted toT magnesium
F oxide b
magnesiumsupply
hydroxide
�������������������������������
also required for the formation of the calcium pectate of the middle lamella
heating in a large furnace under high pressure. The magnesium oxide
raw material and final product
which cements plant cells together.
passed into a kiln at very high temperatures where it is converted from
low density state to a more stable, unreactive, high density oxide.
����������������������������������
Learning Objectives
True or False
On completing this lesson the student should be able to:
Indicate whether the following are true (T) or false (F)
by drawing a circle around T or F.
General Learning Points
•
Limestone is a naturally occurring mineral and deposits can be found
This manufacturing
process
is automated and closely controlled by
all over the
world.
computer.
•
•
It takes about 2 tons of limestone to make one ton of quicklime and a
traditional kiln might produce about 15 tons of lime per day, enough
to fertilise 2 to 5 acres. It is easy to see why lime making was such a
thriving business.
Lime has the unusual property that if it is heated strongly by a
hydrogen/oxygen gas flame it becomes incandescent. This
phenomenon was used in theatres to light the stage. Hence the
expression limelight.
•
Lime is used in the pulp and paper industry. One such use is for
bleaching.
•
Hydrated lime is widely used for sugar refining. It raises the pH level
and also helps to remove impurities.
•
When fruit and vegetables ripen they emit CO2. Bags of hydrated lime
are used to absorb this and the fruit and vegetables can stay fresh for
much longer periods.
•
Lime is widely used in the petroleum industry for neutralising organic
sulphur impurities.
•
Large quantities of lime are used to remove SO2 from waste gases.
This process is called desulphurisation.
(g) Lime cannot burn the skin
T
F
(h) Mortar is a mix of lime and sand
T
F
(i) Lime is good for neutralising acid in soils and in lakes
T
F
(j) Slaked lime is used in the production of magnesium
oxide from seawater
T
F
(k) The place in which limestone is burned at high
temperatures is called a hydrator
T
F
(l) If you mix lime, sand, water and stones you get cement
T
F
Check your answers to these questions on
www.sciencetechnologyaction.com
an
an
Clogrennane Lime – Producing
Essential Chemical
Essential Chemical
Dark Blue: Pantone 289
Light Blue: Pantone 646
Lime is a vital chemical
Why is the lime mixed with water?
Protecting the environment
Lime is one of the most important chemicals and has been
used by people all over the world from early times. In this
lesson we look at the chemistry of lime, how it is manufactured
and some of its many uses.
Quicklime is a caustic chemical which burns flesh. Many farm workers
of old discovered this to their horror when quicklime got in their eyes.
Quicklime is still used to destroy carcasses quickly, for example, during a
foot and mouth epidemic. Care must be taken when using lime. It is much
safer in the form of slaked lime. When quicklime is mixed with water it is
turned from quicklime to calcium hydroxide, which is called slaked lime.
This reaction is shown in the following equation
When acid rain falls into lakes it rapidly acidifies them, posing a seriou
threat to all aquatic life. The lakes are crystal clear but dead. This can b
remedied by regular application of lime to the lake which neutralises th
acid. In places like Sweden the lakes are often inaccessible so helicopte
are used to spread the lime
CaO + H2O = Ca(OH)2
Examination Questions
2002 Higher Level
Distinguish
between
Fig.1 The Clogrennane
Plant a batch and a continuous
Biographical Notes
What is lime used for?
Sir Humphrey Davy
Lime is used extensively in many industrial processes such as steel
manufacturing, mining, ceramics and glass-making. We now look at
some
of its uses
in building, agriculture, environmental protection, the
production
process.
(6)
an English scientist born in
manufacturing of iron and the production of magnesium oxide from
seawater.
understanding of chemistry.
1778, made significant contributions to our
By running a current through a number of
Answer
the following questions in relation to one of the following
How
is both
lime of
made?
substances, he was able to isolate metallic elements such as potassium,
processes:
It is remarkable that the process used by the earliest cultures to produce
Building uses
sodium, magnesium, calcium and barium. Another
one of Davy’s
lime is still in use today. It is easy to make providing you have limestone
Fig.3 Spreading of lime on a lake
and a •
hotAmmonia
fire. If you getmanufacture
a really strong fire going on limestone (calcium
Lime Mortar is a mixture of lime and sand
used to bed stones
in walls. Over
experiments
consisted
of
rubbing
two
ice
cubes
together
and observing
carbonate) and let it burn overnight, lime will be formed under it. This lime
time lime mortar reacts with carbon dioxide to form calcium carbonate
Industrial
production
of iron
shows•as Nitric
a white patch.
equation for its formation is
theyThe
melted,
in contradiction
to the caloric
theory. He also
invented the
acid The
manufacture
which hardens to hold the stonesthat
in place.
sand helps
bind the
calcium carbonate and also allows air and carbon dioxide into the mixture.
Limestone
is used
the production
of iron.
is added
CaCO3 = CaO + CO2
famous Davy lamp used by miners.
In 1812
hein was
knighted
for Ithis
work.to the smelt
In
effect,
the
slaked
lime
has
been
converted
back
to
limestone.
as one of three layers - iron ore, limestone, and coke. The limeston
• Magnesium oxide manufacture
The limestone has been converted to lime (calcium oxide) and carbon
In 1827, he became seriously illdecomposes
due to his
inhalation
and
forms CO2. of many gases over
Ca(OH)2 + CO2 = CaCO3 + H2O
dioxide. Calcium oxide is also known as quicklime.
(i) In relation to your chosen chemical industry state one reason in favour
the years. He died in1829 in Switzerland.
CaCO3 = CaO + CO2
The place
in which
limestone
is burned
of the
Irish
location
of this industrial plant. (4)
Some of this CO2 is reduced by the coke to CO which reduces the iro
Romans invented concrete
is called a limekiln. Old limekilns are
oxide to iron. The CaO reacts with the SiO2 (sand) in the ore to form sla
found all over Ireland because lime
know that mortar was
(ii) Give a brief outline of the processes carried out in theWemanufacture
of used by the Romans. Concrete is simply mortar
was essential for many uses. It could
CaO + SiO2 = CaSiO3
stones in it and it was used by the Romans to fill the huge spaces
be easily
theregiving
was
themade,
mainproviding
product,
balanced chemical equationswith
where
relevant.
behind facing stone blocks. It would have been impossible for them to
The iron sinks to the bottom and so does the slag but the slag floats o
a supply of limestone in the locality.
(15)
build structures such as the Pont du Gard using all cut stone. Lime was
top of the iron as it is less dense. The slag is tapped off first followed b
Lumps of limestone were piled on top
of a fire. The temperature had to reach
between 900 and 1100°C and the kiln
would be left to burn for a week or
more. This means that it was a batch
process. The heating of limestone to
produce calcium oxide is known as
calcination. Modern kilns operate a
continuous process. Limestone is fed
Fig.2 The kiln at Clogrennane
on a conveyor into the kiln and the
product (lime) is fed out and stored in bags for sale. The picture shows
the kiln at Clogrennane Lime Ltd. in Co. Carlow. The process used there is
outlined in the following diagram.
You can find out more about these and other great
the iron. The slag is used as road metal, fertiliser and even insulation
scientists at www.sciencetechnologyaction.com
houses when treated appropriately.
precious and mixing stones in with the sand and lime made it go a lot
further. They discovered that by mixing broken tiles in with the lime and
stones, the concrete hardened faster and even hardened underwater.
This of course made it possible to build in previously unusable areas and
places.
For further examples of past paper exam questions check
out www.sciencetechnologyaction.com
Whitewash is a mixture of lime and water and, sometimes, other additives
Did You Know?
•
•
•
such as chalk. It is a cheap and effective way of keeping houses looking
good. It also has antiseptic properties. Hence whitewashing the insides of
animal houses is a common practice on farms.
Agricultural uses
������������������������������������
In the middle ages it was discovered that the addition of lime to soil
The earliest recorded use of lime for construction was
around
4000
improved
drainage
and reduced soil acidity. Lime is now widely used as a
BC. It������������������������������������������������������������
was used in Egypt for plastering the pyramids. fertiliser. In acid soils the lime neutralises the soil acid which leads to better
grazing. Lime also acts as a soil improver. It causes particles of soil to stick
�����������������������������������
together (flocculation) and this makes the spaces between the particles
Lime was used in the construction of the Great Wall ofbigger.
China.
These bigger spaces improve the drainage and aeration in clay
soils. The use of lime leads to much improved plant growth. Calcium is
�������������������������������������������������������������
A Roman architect
called Vitruvius composed some basic
guidelines
�������������������������������
also required
for the formation of the calcium pectate of the middle lamella
cements plant
cells together.
for producing mortar. ‘When [the lime] is slaked, let it which
be mingled
with
the sand in ����������������������������������
such a way that if it is pit sand, three of sand and one of
lime is poured in; but if the same is from the river or sea, two of sand
This manufacturing process is automated and closely controlled by
and one of lime is thrown together.’
computer.
• A man called James Parker patented a product called Roman cement
or natural cement in 1796. This was produced by burning a mixture of
limestone and clay together in a kiln.
• Joseph Aspdin, who was an English builder, patented a cement called
Portland Cement in 1824. This type of cement is still used today.
• Hydrated lime is also used in the manufacture of toothpaste, paints,
sugar and glass.
Revise the Terms
Production of magnesium oxide
Another major industrial process that involves the use of limeston
is the manufacture of magnesium oxide from sea water. It is carrie
out by Premier Periclase in Drogheda, Co. Louth. A sister company
Clogrennane, Premier Periclase also uses a continuous process whic
involves a constant supply of raw materials and a constant supply of th
product.
Limestone is used to produce calcium hydroxide in the manner describe
previously. Seawater is acidified with sulphuric acid and passed through
tower against a current of air which removes carbon dioxide. This is know
as degassing. The calcium hydroxide is then reacted with the degasse
water and soluble magnesium ions in the seawater form a precipitate wi
the hydroxide ions from the calcium hydroxide
MgCl2 + Ca(OH)2 = CaCl2 + Mg(OH)2
The magnesium hydroxide is then converted to magnesium oxide b
heating in a large furnace under high pressure. The magnesium oxide
passed into a kiln at very high temperatures where it is converted from
low density state to a more stable, unreactive, high density oxide.
Can you recall the meaning of these terms? Reviewing the
terminology is a powerful aid for recall and retention.
Lime; limestone; calcium carbonate; lime; carbon oxide; carbon dioxide;
quicklime; limekiln; batch process; calcination; continuous process;
conveyor; limestone quarry; calcinated; kiln; hydrator; calcium hydroxide;
slaked lime; magnesium oxide; lime mortar; concrete; whitewash; fertiliser;
soil; improver; flocculation; calcium pectate; middle lamella; acid rain; iron
oxide; iron; slag; SiO2; magnesium oxide; degassing; magnesium ions;
hydroxide ions.
• Iron is the most abundant heavy metal on the earth as it does not
require a catalyst in its formation.
• The first signs of use of iron came from about 4000BC.
• Magnesium constitutes about 2% of the earth’s crust by weight.
• As well as magnesium ions, Mg2+, seawater contains Cl-, Na+,
SO42-, Ca2+, K+, HCO3-, Br - , H2BO3-, Sr2- and F-.
• Slaked Lime is also called Hydrated Lime.
• Calcium is the fifth most common element in the earth’s crust after
oxygen, silicon, aluminium and iron.
Check the Glossary of Terms for this lesson at
www.sciencetechnologyaction.com