QUANTUM AND STATISTICAL REPORT
A Project Report on
Study of Calcium Carbonate [CaCO3]
By:
Bhavya Shah
I031
Aman Sohail
I034
Manas Patel
I037
Department of MBA Tech (Information Technology)
Mukesh Patel School of Technology Management & Engineering
April 2022
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TABLE OF CONTENTS
1. Introduction ............................................................................... 3
1.1 Nomenclature .......................................................................... 3
2. Types of Calcium Carbonate .................................................... 4
2.1 Calcite ..................................................................................... 4
2.2 Aragonite ................................................................................. 5
2.3 Dolomite.................................................................................. 6
3. Elemental Analysis ................................................................... 7
3.1 Occurrence .............................................................................. 7
3.2 Appearance.............................................................................. 8
3.3 Structure .................................................................................. 8
4. Preparation ................................................................................ 9
4.1 Existence in Nature ................................................................. 9
4.2 Preparation of crystalline form ............................................... 9
4.3 Preparation of amorphous form .............................................. 10
5. Factors affecting Preparation .................................................... 10
5.1 temperature.............................................................................. 10
5.2 pH and Pressure ...................................................................... 11
5.3 Calcium and carbonate ion concentration ............................... 12
6. Properties .................................................................................. 12
6.1 Physical Properties .................................................................. 12
6.2 Chemical Properties ................................................................ 13
7. Uses and applications ................................................................ 13
8. Future aspects of calcium carbonate ......................................... 14
9. Reference................................................................................... 16
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1. Introduction
Calcium carbonate, or CaCO3, comprises
more than 4% of the earth’s crust and is found
throughout the world. It’s most common
natural forms are chalk, limestone, and
marble, produced by the sedimentation of the
shells of small fossilized snails, shellfish, and
coral over millions of years. Although all
three forms are identical in chemical terms,
they differ in many other respects, including
purity,
whiteness,
thickness
and
homogeneity. Calcium carbonate is one of
the most useful and versatile materials known
to man.
Many of us encounter calcium carbonate for
the first time in the school classroom, where
we use blackboard chalk. Chalk has been
used as a writing tool for over 10,000 years
and is a fine, microcrystalline material. As
limestone, calcium carbonate is a biogenic
rock, and is more compacted than chalk. As
marble, calcium carbonate is a coarsecrystalline, metamorphic rock, which is
formed when chalk or limestone is
recrystallized under conditions of high
temperature and pressure. Large deposits of
marble are found in North America and in
Europe; e.g., in Carrara, Italy, the home of the
pure white "statuario" from which
Michelangelo created his sculptures.
Calcium carbonate, as it is used for industrial
purposes, is extracted by mining or
quarrying. Pure calcium carbonate can be
produced from marble, or it can be prepared
by passing carbon dioxide into a solution of
calcium hydroxide. In later case calcium
carbonate is derived from the mixture,
forming a grade of product called
"precipitated calcium carbonate,” or PCC.
PCC has a very fine and controlled particle
size, on the order of 2 microns in diameter,
particularly useful in production of
paper. The other primary type of industrial
product is "ground calcium carbonate,” or
GCC. GCC, as the name implies, involves
crushing and processing limestone to create a
powdery-like form graded by size and other
properties for many different industrial and
pharmaceutical applications.
A study of calcium carbonate provides
important lessons about the history of the
earth, since chalk, limestone and marble trace
their origin to shallow water.
Thus,
observation that large amounts of chalk
deposits of the same age are found on many
continents led to the discovery that there
existed a period in which there was shallow
water world-wide where shelled organisms
thrived. Some offer this as proof for the
Biblical flood.
1.1 Nomenclature
1.1.1 Nonproprietary Names
Recommended international nonproprietary
name is termed as Calcium Carbonate.
Synonyms: E 170, calcite, aragonite, vaterite,
chalk, CI pigment white 18, drop chalk,
whiting, English white, Paris white.
1.1.2 Proprietary Names
Caltrate (Pfizer Consumer Healthcare),
Maalox Quick Dissolve (Novartis Consumer
Healthcare), Maalox Regular Strength
(Novartis Consumer Healthcare), Os-Cal,
Alka-Seltzer, Alcalak (Medique Products),
Oyster Shell Calcium (Swanson Health
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Products), Oysco, Cal-Gest (Rugby), Icar
Prenatal Chewable Calcium (Hawthorn
Pharmaceuticals), Oyster Shell Calcium,
Children’s Pepto, Rolaids Soft Chew, Adcal
1500 Chewable (Biokirch), Ostocal,
Calcichew, Calcichew 500 mg purutabletti,
Calcichew Spearmint 500 mg purutabletti,
Calcimagon 500 mg, Calcioral, astical,
Calcitugg, Boots.
2. Types of Calcium Carbonate
2.1 Calcite
Calcite is a rock-forming mineral with a
chemical formula of CaCO3. It is extremely
common and found throughout the world in
sedimentary, metamorphic, and igneous
rocks. The most common form of calcium
carbonate, calcite is known for the variety
and beautiful development of its crystals.
These occur most often as scalenohedra and
are commonly twinned, sometimes forming
heart-shaped, butterfly twins. Crystals with
rhombohedra terminations are also common;
those
with
shallow
rhombohedral
terminations are called nail head spar. Highly
transparent calcite is called optical spar.
Although calcite can form spectacular
crystals, it is usually massive, occurring
either as marble (p.301) or as limestone
(p.319). It is also found as fibers, nodules,
stalactites, and earthy aggregates. Calcite
specimens can occur in metamorphic
deposits, igneous rocks, and hydrothermal
veins.
Some geologists consider it to be a
“ubiquitous mineral” – one that is found
everywhere. Calcite is the principal
constituent of limestone and marble.
These rocks are extremely common and
make up a significant portion of Earth’s crust.
The properties of calcite make it one of the
most widely used minerals. It is used as a
construction material, abrasive, agricultural
soil treatment, construction aggregate,
pigment, pharmaceutical and more.
The composition of calcite is, CaC03. CaO =
56.0 per cent, C02 = 44.0 per cent. Small
amounts of magnesium, ferrous iron,
manganese, and zinc may replace the
calcium. The diagnostic feature are its
softness, its perfect cleavage, light color,
vitreous luster. Distinguished from dolomite
by the fact that fragments of calcite
effervesce freely in cold hydrochloric acid,
whereas those of dolomite do not.
Distinguished from aragonite by having
lower specific gravity and rhombohedral
cleavage.
Figure 1 Structure of Calcite
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Calcite most commonly occurs in
sedimentary settings, particularly in shallow
marine settings as the shells and hard parts of
marine organisms. It is also found in
hydrothermal veins and hot spring deposits.
In sedimentary environments, calcite most
often occurs as limestone rock or as marble,
which is metamorphosed limestone. Calcite
is often the only mineral present, but in some
sedimentary environments, calcite may be
associated with dolomite, gypsum, anhydrite,
chert, or halite. In hydrothermal veins, quartz
and other common vein minerals such as
pyrite, dolomite, fluorite, galena, and
chalcopyrite may occur with calcite
(Kauwenbergh, 2010).
2.1.1 Geological Importance
All natural waters contain dissolved calcium
and carbon dioxide, and their concentration is
especially high in seawater.
Many marine animals including corals,
snails, clams, algae, and microscopic
plankton use calcite and aragonite to form
their shells and hard parts.
Microorganisms can also indirectly lead to
the precipitation of calcite as they alter the
chemistry of the fluids in which they live.
Once formed, calcite is easily dissolved and
its component ions released to precipitate
elsewhere.
As a consequence, calcite is not only the main
mineral of limestone rocks and marble
(metamorphosed limestone), but also a
common accessory component of sandstone
and siltstone rocks.
2.1.2 Distribution
Countries of origin for calcite are almost
every continent. Large deposits of brightly
colored calcites occur in Mexico and the
USA.
Calcite is distributed in the following places:
Iceland -Helgustadanama mine, Reydarfjord.
England – From Alston Moor, Egremont, and
Frizington, Cumbria; Weardale, Durham; at
Liskeard, Cornwall,
Germany – From St. Andreasberg, Harz
Mountains, and Freiberg, Saxony,
Namibia – From Tsumeb,
Congo – Mupine mine, Katanga Province,
Romania – At Herja (Kisbanya), Baia Mare
(Nagybanya) district,
Russia – At Dalnegorsk, Primorskiy Krai.
2.2 Aragonite
Aragonite is a carbonate mineral and its
formula is calcium carbonate. It has the same
formula as Calcite and Vaterite, but has a
different crystal structure. They are tabular,
prismatic or needle-like, often with steep
pyramidal or chisel-shaped ends, and can
form columnar or spreading aggregates.
Multiple twin crystals that appear hexagonal
in shape are common. Although aragonite
sometimes resembles calcite, it is easily
distinguished by the absence of rhombic
cleavage. Samples can be white, colorless,
gray, yellowish, green, blue, reddish, purple
or brown. Aragonite is found in oxidized
areas of ore deposits and in evaporates, hot
spring deposits and caves. It is also found in
some metamorphic and igneous rocks and is
formed by biological and physical processes,
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including precipitation from marine and
freshwater environments. Its first noted
occurrence was in Aragon region of Spain.
2.2.1 Occurrence
It turns into calcite over geological time.
Primary sediment in warm marine waters
such as oolites and carbonate mud, an
essential clastic sedimentary component as
the hard parts of the shells and skeletons of
many marine micro-organisms; also from
evaporite deposits; in sinter in hot springs and
in stalactite in caves; characteristic of high
pressure, low temperature (blueschist facies)
metamorphism; as amygdullary in basalt and
andesite; It is a secondary component in
altered ultramafic rocks.
Aragonite is a high pressure polymorph of
calcium carbonate. Therefore, it occurs in
high pressure metamorphic rocks such as
those formed in subduction zones.
Aragonite is metastable at low pressures near
the Earth’s surface and is therefore often
replaced by calcite in fossils. Aragonite older
than the Carboniferous is essentially
unknown. It can also be synthesized by
adding a solution of calcium chloride in
water-ethanol
mixtures
at
ambient
temperatures or to a sodium carbonate
solution at temperatures above 60 °C (140
°F).
2.2.2 Distribution
Many localities, but fine crystals are
uncommon.
From Molina, Guadalajara Province, Spain.
Fine crystals from Racalmuto, Cianciana, and
Agrigento, Sicily, Italy.
At Dogn´acska and Spania Dolina
(Herrengrund), Slovakia.
From Tarnowitz, Silesia, Poland.
At ˇ the Erzberg, near Eisenerz, Styria, and
from Leogang, Salzburg, Austria.
On the Spitzberg, Hoˇrenz, near B´ılina,
Czech Republic.
From Frizington and Cleator Moor, Cumbria,
England.
Fine examples at the Touissit mine, near
Oujda, and from Tazouta, near Sefrou,
Morocco.
Large crystals from Tsumeb, Namibia.
In the USA, in caves at Bisbee, Cochise Co.,
Arizona; large crystals from near Lake
Arthur, Chavez Co., also near Santa Rosa,
Guadalupe Co., New Mexico; in the Passaic
mine, Sterling Hill, Ogdensburg, Sussex Co.,
New Jersey.
2.3 Dolomite
Dolomite is an important rock-forming
mineral that named is French mineralogist
Déodat Grated de Dolomieu. It is a colorless
to white, pale brown, grayish, reddish, or
pink mineral. Its crystals are commonly
rhombohedral or tabular, often have curved
faces, and sometimes cluster in saddleshaped aggregates. Dolomite may be striated
horizontally and twinned. Some crystals may
be up to 2 in (5 cm) long. It can also be coarse
to fine granular, massive, and, rarely, fibrous.
Dolomite is the main constituent in dolomite
rocks and dolomitic marbles. It occurs as a
replacement deposit in limestone affected by
magnesium-bearing solutions, in talc schists,
and in other magnesium-rich metamorphic
rocks. Dolomite is found in hydrothermal
veins associated with lead, zinc, and copper
ores. It is also found in altered, silica-poor
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igneous rocks, in some carbonatites, and in
serpentinites. Crystals of dolomite frequently
form in cavities in limestone and marble.
In the Vuoriyarvi carbonatite complex, Kola
Peninsula, Russia.
Fine crystals from Brumado, Bahia, and in
the Morro Velho gold mine, Nova Lima,
Minas Gerais, Brazil.
At Naica, Chihuahua, Mexico.
In the USA, in New York, from Lockport,
Niagara Co., eastward to Walworth, Wayne
Co.; at Stony Point, Alexander Co., North
Carolina; in the Mississippi Valley region, in
the Tri-State district, at Joplin, Jasper Co.,
Missouri; Galena, Cherokee Co., Kansas; and
Picher, Ottawa Co., Oklahoma.
3. Elemental Analysis
Figure 2 Structure of Dolomite
2.3.1 Occurrence
Formed by diagenesis or hydrothermal
metasomatism of limestone; a primary phase
in hypersaline sedimentary environments; a
major component of some contact
metamorphic rocks and marbles; a gangue in
hydrothermal veins; in carbonatites and
ultramafic rocks.
2.3.2 Distribution
A major rock-forming mineral, abundant
worldwide with numerous commercial uses.
Some localities for fine examples include:
In Italy, from Traversella and Brosso,
Piedmont.
Exceptional crystals from Eugui, Navarra
Province, Spain.
At Trieben and Hall, Tirol, Austria. From
Freiberg and Schneeberg, Saxony, Germany.
At Lengenbach, Binntal, Switzerland. From
Trepca, Serbia, Yugoslavia. At Frizington,
Cumbria, England.
The IUPAC name is Calcium Carbonate,
which is also known as names like aragonite,
calcite, chalk, limestone, and marble, pearl.
The chemical formula of calcium carbonate
is CaCO3 with molar mass of 100.08 g/mol.
3.1 Occurrence
3.1.1 Biological Source
Eggshells, snail shells and most seashells are
predominantly calcium carbonate and can be
used as industrial sources of that
chemical. Oyster shells have enjoyed recent
recognition as a source of dietary calcium,
but are also a practical industrial
source. Dark green vegetables such
as broccoli and kale contain dietary
significant amounts of calcium carbonate, but
they are not practical as an industrial source.
3.1.2 Geological source
Calcite, aragonite and vaterite are pure
calcium carbonate minerals. Industrially
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important source rocks which are
predominantly
calcium
carbonate
include limestone, chalk, marble and traverti
ne.
3.1.3 Extraterrestrial
Beyond Earth, strong evidence suggests the
presence of calcium carbonate on Mars.
Signs of calcium carbonate have been
detected at more than one location (notably
at Gusev and Huygens craters). This provides
some evidence for the past presence of liquid
water.
occurring as the mineral vaterite. The
aragonite form can be prepared by
precipitation at temperatures above 85 °C;
the vaterite form can be prepared by
precipitation at 60 °C. Calcite contains
calcium atoms coordinated by six oxygen
atoms; in aragonite they are coordinated by
nine oxygen atoms. The vaterite structure is
not
fully
understood.
Magnesium
carbonate (MgCO3) has the calcite structure,
whereas strontium carbonate and barium
carbonate (SrCO3 and BaCO3) adopt the
aragonite
structure,
reflecting
their
larger ionic radii.
3.2 Appearance
According to the United States Pharmacopeia
(USP), CaCO3 is fine, white, Odorless,
tasteless, and microcrystalline powder, while
it is described as a white or almost white
powder in the European Pharmacopeia (Eur. Ph.).
Figure 4 Calcium Carbonate
Figure 3 Molecular Structure of Calcium Carbonate
3.3 Structure
The thermodynamically stable form of
CaCO3 under normal conditions is hexagonal βCaCO3 (the mineral calcite). Other forms can be
prepared,
the
denser
(2.83 g/cm3) orthorhombic λ-CaCO3 (the
mineral aragonite) and hexagonal μ-CaCO3,
Figure 5 Ionic Structure of Calcium Carbonate
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4. Preparation
4.1 Existence in nature
CaCO3 is one of the most abundant materials
found in earth’s crust and forms the rock
types like limestone and chalk.
Moreover, it is the most abundant chemical
sediment in modern and most ancient oceans,
making up roughly 10% of sediments.
CaCO3 can be a dominant sedimentary
constituent in virtually any environment, at
any latitude, and in any depth of water. On
the other hand, carbonates are forming
extensively in many regions in the western
margins of large oceans, in both the southern
and northern hemispheres, at seawater
temperatures ranging from about _2 to 40°C.
Nearly all the CaCO3 that makes up
carbonate platforms is derived from marine
organisms. CaCO3 is also an important
component in biological systems, such as
shells of marine organisms, pearls, and egg
shells. Some of these systems, Eg, Oyster
shells, have enjoyed recent recognition as a
source of dietary Ca, but are also a practical
industrial source. While not practical as an
industrial source, dark green vegetables such
as Broccoli and Kale contain dietary
significant amounts of CaCO3.
Carbonates are largely made up of skeletal
remains and other biological constituents that
include fecal pellets, lime mud (skeletal), and
microbial mediated cements and lime muds.
4.2 Preparation of crystalline form
CaCO3, upon precipitation, is capable of
forming an amorphous phase comprising
colloidal systems of amorphous primary
particles. The colloidal stability of these
systems is not sufficient to prevent
aggregation. Due to the high number density
of primary particles and the high ionic
strength of the solution, the aggregation
process leads to a gelation of the reaction
mixtures.
The gel is bound by van der Waals forces
only. Therefore, the gel is colloid less stable
and undergoes a quick morphological
collapse. The recrystallization to vaterite or
calcite takes place simultaneously with the
dissolution of the gel.
The sequence of reactants directly affects the
morphological structure of CaCO3 upon
precipitation. For example, if Na2CO3
solution is first introduced into the reactor
and then CaCl2 solution is fed to this solution
under standard conditions, the product
consists almost entirely of vaterite. The
increase in particle size is due to spherulitic
growth mechanism of vaterite caused by
multiple passages of the particle through the
region of maximum supersaturating at the
feed inlet. For the reversed sequence case a
larger percentage of calcite. The calcite cubes
are aggregated to form larger irregular
particles and are partly overgrown by clusters
of vaterite. This may be due to the same
mechanism as in the standard experiment
(first case), with the vaterite nucleating on the
Calcite surface. When MgCl2 is introduced
into CaCl2 solution to avoid premature
precipitation, some calcites are formed but all
the particles are mainly vaterite. The vaterite
particles of various shapes are aggregated
and of various shapes. When KOH is
introduced into Na2CO3 solution for the same
purpose, large calcite particles and smaller
aragonite needles, which are attached to the
calcite cubes, are formed.
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4.2.1 Calcium
Dioxide
acetate
and
Carbon
The hierarchical monodispersed aragonite
microspheres can be prepared by carbonating
Ca(CH3COO)2 aqueous solution with CO2
gas at a high pressure 40 bar and a high
temperature of 80°C after 60 min of reaction.
Ca(CH3COO)2
aqueous
solution
is
introduced into a reactor under atmospheric
pressure. Pure CO2 gas is then continuously
introduced until it reaches the setting
pressure. During the experiments, the CO2
pressure in the reactor is kept constant by
continuous supplying of CO2 from the
cylinder using a pressure controller. After a
given time, the stirring is stopped.
The obtained precipitates are collected from
the man-made filter and washed several times
with water as well as anhydrous ethanol then
air dried. The reaction between CO2 and
Ca(CH3COO)2 in an aqueous solution was
first proposed by Kakizawa et al. For the
fixation of the greenhouse gas CO2 into solid
CaCO3. Generally, CaCO3 can be dissolved
in a CH3COOH solution at atmosphere
conditions. Therefore, CH3COOH is replaced
by H2CO3 in this carbonation crystallization
process, resulting in precipitating CaCO3
particles. Moreover, it is reported that the
reaction between CO2 and Ca(CH3COO)2 is
endothermic and occurs spontaneously at
temperatures above 45°C at an atmospheric
pressure.
4.2.2 Quicklime or Hydrated Lime
Limestone is converted to CaO by heat,
followed by formation of milk of lime
(Ca(OH)2) either by slaking quicklime or by
dispersing hydrated lime in water. Finally,
Ca(OH)2 is combined with CO2 to form
precipitated CaCO3.
4.3 Preparation of Amorphous form
4.3.1 Calcium Chloride and Sodium
Carbonate
CaCl2 and Na2CO3 solutions, equimolar in Ca
and carbonate ions, are rapidly mixed. For
example, 106 mg of solid Na2CO3 is added to
20 mL of a 0.5 M NaOH solution and 30 mL
of water. This solution is combined with 50
mL of a 20 mM CaCl2 solution and stirred
rapidly, followed immediately by vacuum
filtration and rinsing with acetone to dry the
solid.
4.3.2 Calcium Hydroxide and Carbon
Dioxide
Precipitates of pure amorphous CaCO3 can
be obtained by bubbling CO2 through a
saturated Ca(OH)2 solution at 0°C. The
precipitation is stopped when the pH reaches
8 and the precipitate is filtered and rinsed
with cold acetone. The precipitate dried
under high vacuum at 0°C for 36 h and stored
under phosphorous pentoxide in a desiccator.
Ikaite (CaCO3.6H2O) is prepared in the same
way as the amorphous, but the precipitate is
not dried in a vacuum after washing with
acetone, instead, it is immediately placed in a
freezer at 20°C.
5. Factors affecting preparation
5.1 Temperature
The influence of temperature on CaCO3
polymorph formed from (NH4)2CO3–
Ca(CH3COO)2 system was investigated. At
25 and 80°C, the predominant form was
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QUANTUM AND STATISTICAL REPORT
found to be vaterite, while calcite form was
obtained at 50°C. Less than 5% aragonite was
observed at 70°C. In CaCl2–Na2CO3
system, vaterite with specific morphologies
was formed at 2–35°C, whereas needleshaped aragonite crystals were obtained at
50–70°C.
Figure 6 Temperature v/s Calcium ion
5.2 ph and Pressure
The effect of pH on the polymorphic phase
and crystal growth upon precipitation of
CaCO3 was investigated by using gas
diffusion method.
At pH 0.5, calcite and aragonite crystals are
obtained. When the pH value was higher than
5.5, the precipitates are calcite crystals with
different morphologies and particle sizes. It
was also reported that calcite precipitation in
water was favored in alkaline conditions. Han
et al. also reported that higher pH value
tended to induce calcite crystals. Cheng et al.
and Yu et al. also reported that greater
morphology control can be afforded by low
supersaturation as pH is decreased. This
means that the induction time of CaCO3
precipitation increases considerably with
decreasing pH.
The effect of pressure on transition of calcite
forms was first studied by Bridgman. It was
observed a transition to a slightly denser
phase (calcite II) at 1.44 GPA and a transition
to a significantly denser phase (calcite III) at
1.77 GPA. Singh and Kennedy and Merrill
and Bassett placed the calcite I–calcite II
transformation at 1.45 and 1.5 GPA and the
calcite II–III transformation at 1.74 and 2.2
GPA, respectively. Moreover, the phase
transition of metastable calcite III–post
calcite III initiates at a pressure of 15.5 GPA
and is completed between 25 and 30 GPA. In
addition to the aforementioned calcite form,
there exists a denser calcite VI form that can
be formed using shock compression
experiments. The phase diagram of calcite is
further complicated by the appearance of the
calcite II and calcite III intermediates at highpressure phases in the range from 1.0 to 2.5
GPA. At higher pressures, calcite is known to
undergo yet another phase transition; this
high-pressure phase, known as calcite IV,
occurs at pressures in excess of 10 GPA and
is usually observed in impact experiments in
the form of a somewhat anomalous
rarefaction shock.
Figure 7 pH v/s Calcium ion
None of the intermediate phases of calcite is
stable under equilibrium conditions. Karley
developed a theoretical model for the
STUDY OF CALCIUM CARBONATE
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equation of state of CaCO3 that includes
phase transitions and melting. As noted,
calcite IV is assumed to have the same
properties as aragonite except for a shift in
the energy. Different CaCO3 phases have
been determined by using a combination of
advanced ab initio simulation techniques and
high-pressure experiment. The crystal
structure of post aragonite phase in CaCO3 at
a pressure of 40 GPA was identified in
addition to a number of energetically
competitive structures (stable phase I and
metastable phases II–IV). Above 137 GPA,
phase I with a pyroxene-type structure with
chains of CO4 tetrahedral becomes more
stable than post aragonite.
5.3 Calcium and Carbonate Ion
concentration
The effect of Ca/CO3 concentration ratio on
CaCO3 particles size and shape, prepared
from CaCl2 and Na2CO3 system, was
investigated. It was found that particles’
shape changed from squared, spherical, to
oblong by increasing the concentration (g/L)
ratio of Ca/CO3 from 0.21 to 1.22. On the
other hand, the average particle size changed
from 3.5 to 1.8 μm[119,120]. It was
explained by formation of soluble complexes
Coax (CO3)y at excess CO3 anions, which
lowers the supersaturation and, accordingly,
the primary nucleation rate.
6. Properties
6.1 Physical Properties
Calcium carbonate appears as white, odorless
powder or colorless crystals. Practically
insoluble in water. Occurs extensive in rocks
world-wide. Ground calcium carbonate
(CAS: 1317-65-3) results directly from the
mining of limestone. The extraction process
keeps the carbonate very close to its original
state of purity and delivers a finely ground
product either in dry or slurry form.
Precipitated calcium carbonate (CAS: 47134-1) is produced industrially by the
decomposition of limestone to calcium
oxide followed by subsequent carbonization
or as a by-product of the Solvay process.
Precipitated calcium carbonate is purer than
ground calcium carbonate and has different
handling properties. Limestone (calcium
carbonate) that has been recrystallized by
metamorphism and is capable of taking a
polish.
Compound Formula
Molecular mass
Appearance
Melting point
Boiling point
Density
Acidity
Refractive index
CaCO3
100.09 g/mol
White powder
825oC
N/A
2.93 g/cm3
9.0
1.59
6.1.1 Optical Property
Carbonates can easily be recognized in soil
thin sections, as their birefringence is
extreme resulting in upper-order creamy
white interference colors.
They are also characterized by high relief
generally from strongly negative to strongly
positive depending upon their orientation.
6.1.2 Polymorphism
CaCO3 exists naturally in six different forms:
three crystalline polymorphs, calcite, aragonite,
STUDY OF CALCIUM CARBONATE
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QUANTUM AND STATISTICAL REPORT
and the metastable vaterite; two hydrate phases,
monohydrocalcite and ikaite; in addition to
amorphous CaCO3.
6.2 Chemical Properties
6.2.1 Ionization Constant
Chemical equilibria of CaCO3 in aqueous
solution can be described as H2CO3
undergoing dissociation to give H+, HCO3_,
and CO3 ionic species. The corresponding
dissociation constants pKa1 and pKa2 are
6.35 and 10.32 at 25°C, respectively.
However, the presence of Ca ions leads to the
formation of CaHCO3+ CaCO3, and CaOH+
in solution with association constants
pKCaHCO3+pKCaOH+ , and pKCaCO3 of
1.26, 1.49, and 3.22 at 25°C, respectively.
6.2.2 Solubility Characteristics
According to the USP, it is practically
insoluble in water. Its solubility in water is
increased by the presence of any ammonium
salt or of CO2. The presence of any alkali
hydroxide reduces its solubility.
Figure 8 Solubility v/s pH of Calcium Carbonate
It is insoluble in alcohol. It dissolves with
effervescence in 1 N CH3COOH, in 3 M
HCl, and in 2 M HNO3. The solubility of
CaCO3 (conventional) in water is 16.6 mg/L
(20°C, pH 9–9.4), while that of the aragonite
and calcite forms is 6.6 mg/L (20°C) and 11
mg/L (20°C) for the vaterite form. The
amorphous form of CaCO3, with particles
predominately in the nanoscale range, is
approximately 10 times more soluble than
crystalline CaCO3. In general, the solubility
of the hydrate forms of CaCO3 was found to
be higher than those of anhydrous forms
calcite, aragonite, and vaterite.
7. Uses and Application
CaCO3 is authorized as a food color in the
European Union (EU) under Directive
94/36/EC and is also authorized as an
additive generally permitted in foodstuffs
under Directive 95/2/EC. It is also included
in Directive 2001/15/EC on substances that
may be added for specific nutritional
purposes in foods for particular nutritional
uses, and in Directive 2002/46/EC relating to
food supplements, and it can be used in
fortified foods according to Regulation
1925/200626 on the addition of vitamins and
minerals and of certain other substances in
food. CaCO3 has been evaluated by Joint
FAO/WHO Expert Committee on Food
Additives (JECFA) in 1965, when the
Committee established an acceptable daily
intake (ADI) not limited. The EU Scientific
Committee of Food (SCF) evaluated CaCO3
as part of a group of carbonates and assigned
a group ADI not specified.
CaCO3 together with other carbonates has
also been reviewed by TemaNord, who
concluded that there was no need for a
reevaluation.
The SCF allocated a tolerable upper intake
level (UL) for Ca of 2500 mg/person per day
STUDY OF CALCIUM CARBONATE
13
QUANTUM AND STATISTICAL REPORT
as a nutrient and also established a population
reference intake of 700 mg Ca/day (range
400–1200 mg/day depending on age and
physiological status).
CaCO3 is included in Commission Decision
2006/257, establishing an inventory of
ingredients in cosmetic products. In
pharmaceuticals, CaCO3 is used as an
excipient and as an active ingredient of
antacids. It is also included in Directive
91/41428 concerning the placing of plant
products on the market. CaCO3 has been
registered under the Reach Regulation
1907/2006.
CaCO3 is included in the Food and Drug
Administration (FDA) list of food additives
that are generally recognized as safe (GRAS)
for use in nutrient and dietary supplements,
and is also certified by the FDA for use in
amounts consistent with good manufacturing
practice to color drugs generally.
CaCO3, both natural and precipitated, is
widely used as a major filler in paper, paint,
adhesives and sealants, and polymers. Also
CaCO3
meets
the
pharmacopeia
requirements as a therapeutic source in
antacids, as Ca supplements, and as a
tableting excipient. As a pharmaceutical
excipient, it is mainly used as diluents,
coating agent, and wet binder in solid dosage
forms, as a base for medicinal and dental
preparations, and as buffering and dissolution
aid in dispersible tablets, as well as food
additive.
CaCO3 is also used as a fire extinguisher
foam filler, as an abrasive in household
cleaners, as a flux in welding rod coatings, as
a diluent in agricultural pesticide dusts, and
as a dusting agent in mines, in the
manufacture of Portland cement, lime, glass,
and metallurgical fluxes.
Some applications are listed as below:
Paper: Calcium carbonate is added in paper
and pulp for filler application. It can also be
used as coating pigment. It improves opacity
and brightness of paper. Both PCC and GGC
are used in the paper-making process.
Paints & coatings: Calcium carbonate is
used as extender in this application. It helps
to densify the final product. It is also used in
finishing coats where high gloss is required.
Plastics: Calcium carbonate is used as
mineral fillers in the plastic sector. Owing to
its compatibility with various polymers, easy
availability and specific particle size it is
widely accepted in the industry.
Adhesives & sealants: Calcium carbonate is
used as basic raw material in formulations of
adhesives and sealants. Various products
include tile adhesives and wet-room sealants
among others.
Others: Calcium carbonate agriculture
application, it is used for soil neutralization,
mineralization and nitrification. It also helps
to improve phosphorus and nitrogen. It is also
used in the pharmaceutical sector in tablets or
filler applications and purification of iron
from iron furnace.
8. Future Aspects of Calcium
Carbonate
The report provides the market value for the
base year 2020 and a yearly forecast until
2028 in terms of volume (Kilotons) and
revenue (USD Million). The market for each
application has been provided on a regional
basis for the aforementioned forecast period.
STUDY OF CALCIUM CARBONATE
14
QUANTUM AND STATISTICAL REPORT
The key industry dynamics, regulatory
scenario, and application markets are
evaluated to understand their impacts on the
product demand over the forecast period. The
growth rates were estimated using
correlation, regression, and time-series
analysis. We have used the bottom-up
approach for market sizing, analyzing key
regional markets, dynamics, and trends for
various products, services, and end uses. The
global market has been estimated by
integrating the regional markets. All market
estimates and forecasts have been validated
through primary interviews with the key
industry participants Inflation has not been
accounted for in order to estimate and
forecast the market Numbers may not add up
due to rounding off North America includes
the U.S., Canada, and Mexico Europe
consists of EU-28, Central & Eastern Europe
along with. Commonwealth of Independent
States (CIS) Turkey has been considered as a
part of Europe Asia Pacific includes South
Asia, East Asia, Southeast Asia, and Oceania
(Australia & New Zealand) Central & South
America includes Central American
countries (excluding Mexico) and the South
American continent. The Middle East
includes Western Asia (as assigned by the
UN Statistics Division) and the African
continent
The global calcium carbonate market was
valued at USD 39,179.27 million in 2020 and
is projected to reach a value of USD 60,702.1
million by 2028. Increasing use of calcium
carbonate in the day to day items such as
paper, plastic, cosmetics, etc. is expected to
drive the market in the forecast period.
Health & hygiene awareness are likely to
have a remarkable impact on the
consumption of paper in the form of tissues
and packaging material. These increased
consumption levels are considered to be the
boosting factors for the growth of the product
over the forecast period.
Figure 9 Calcium Carbonate market revenue 20172028
Owing to the high demand from paper sector
coupled with rising population in countries
such as India and China, Asia Pacific market
gained highest market share in 2020.
Healthy upsurge in the consumption of paper
products in India is projected to be a key
driver for the growth of the calcium
carbonate market in the Asia Pacific region.
As per the stats released by the Indian Paper
Manufacturers Association (IPMA), per
capita consumption in the country is expected
to grow from 13 kilograms in 2018 to nearly
17 kilograms by 2024. Given, the population
size of India, this is likely to offer huge
opportunity to the vendors of calcium
carbonate in the region.
STUDY OF CALCIUM CARBONATE
15
QUANTUM AND STATISTICAL REPORT
Figure 10 Estimation of India print media
Nano calcium carbonate products are
anticipated to provide new avenue for market
vendors over the coming years. Increasing
utilization of plastics and rubber in
automotive sector along with rising R&D
activities to develop new products is
projected to propel the demand for nano
calcium carbonate products.
Indian paper sector is projected to play a key
role in positively influencing the demand for
calcium carbonate products
9. References
 https://www.image.org/page/what_is_cal
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 https://medlineplus.gov/druginfo/meds/a
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nate%20is%20a%20dietary,acid%20indi
gestion%2C%20and%20upset%20stoma
ch.
 https://en.wikipedia.org/wiki/Calcium_c
arbonate
 https://pubchem.ncbi.nlm.nih.gov/compo
und/Calcium-carbonate
 http://www.ema.europa.eu/docs/en_GB/
document_library/Referrals_document/
Calcitugg_30/WC500010592.pdf
 http://www.efsa.europa.eu/en/efsajourna
l/doc/2318.pdf
 M.J. O’Neil, P.E. Heckerman, C.B.
Koch, K.J. Roman, C.M. Kenny, M.R.
D’Arecca,
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Index: An Encyclopedia of Chemicals,
Drugs, and Biologicals, 14th ed., Merck
& Co. Inc., Whitehouse Station, NJ,
2006.
 http://www.drugs.com/comments/calciu
m-carbonate
 https://www.medicines.org.uk/emc/searc
h
 http://drugsjo.blogspot.com
 https://geologyscience.com/minerals/cal
cite/#:~:text=Calcite%20is%20a%20roc
k%2Dforming,beautiful%20developmen
t%20of%20its%20crystals.
 https://geologyscience.com/minerals/ara
gonite/#:~:text=Aragonite%20is%20a%
20high%20pressure,replaced%20by%20
calcite%20in%20fossils.
 https://geologyscience.com/minerals/dol
omite/
 https://en.wikipedia.org/wiki/Calcium_c
arbonate
 United States Pharmacopeia Convention,
United States Pharmacopeia 38/National
 Formulary 33 (USP 38/NF 33),
Description and Solubility, vol. 1, USP
 Convention Inc., Maryland, 2015.
 European Pharmacopeia (Eur. Ph.),
Calcium Carbonate, eighth ed.,
European
 Directorate for the Quality of Medicines,
Strasbourg, France, 2015.
STUDY OF CALCIUM CARBONATE
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