Calciumcarbonat Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
GERUCHLOSES, GESCHMACKLOSES PULVER ODER KRISTALLE.
CHEMISCHE GEFAHREN
Zersetzung beim Erhitzen auf 825°C unter Bildung ätzender Rauchemit Calciumoxid. Reagiert mit Säuren, Aluminiumund Ammoniumsalzen.
ARBEITSPLATZGRENZWERTE
TLV nicht festgelegt.
MAK nicht festgelegt.
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation.
LECKAGE
Verschüttetes Material in Behältern sammeln. Persönliche Schutzausrüstung: Atemschutzgerät, P1-Filter für inerte Partikel.
R-Sätze Betriebsanweisung:
R37/38:Reizt die Atmungsorgane und die Haut.
R41:Gefahr ernster Augenschäden.
R36/38:Reizt die Augen und die Haut.
R36:Reizt die Augen.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
Aussehen Eigenschaften
CaCO3; Kreide, Mamor, Kalk. Weißes Pulver ohne Geruch.
Gefahren für Mensch und Umwelt
Reizt die Augen.
Schutzmaßnahmen und Verhaltensregeln
Geeignete Schutzhandschuhe als kurzzeitiger Staubschutz.
Verhalten im Gefahrfall
Trocken aufnehmen. Der Entsorgung zuführen.
Auf Umgebung abstimmen.
Erste Hilfe
Nach Hautkontakt: Abwaschen.
Nach Augenkontakt: Mit reichlich Wasser bei geöffnetem Lidspalt mindestens 10 Minuten ausspülen. Bei Beschwerden Augenarzt hinzuziehen.
Nach Einatmen: Frischluft.
Nach Verschlucken: Beim Verschlucken größerer Mengen viel Wasser nachtrinken und bei Unwohlsein Arzt konsultieren.
Nach Kleidungskontakt: Kontaminierte Kleidung ausklopfen und waschen.
Ersthelfer: siehe gesonderten Anschlag
Sachgerechte Entsorgung
Als feste Laborchemikalienabfälle.
Beschreibung
Calcium carbonate occurs in nature as limestone in various forms, such as marble, chalk, and coral. It is probably the most widely-used raw material in the chemical industry. It has numerous applications, primarily to produce cement, mortars, plasters, refractories, and glass as building materials. It also is used to produce quicklime, hydrated lime and a number of calcium compounds. It is produced either as powdered or precipitated calcium carbonate. The latter consists of finer particles of greater purity and more uniform size. They also have many important commercial applications. Various grades of precipitated calcium carbonate are used in several products, such as textiles, papers, paints, plastics, adhesives, sealants, and cosmetics.
calcium carbonate block
Chemische Eigenschaften
Calcium carbonate occurs in two forms—hexagonal crystal known as calcite, and orthorhombic form, aragonite. Calcite decomposes on heating at 825°C, aragonite melts at 1,339°C (at 102.5 atm). Density 2.71 g/cm3 (calcite), 2.83 g/cm3 (aragonite); insoluble in water (15mg/L at 25°C); Ksp 4.8x10–9 ; soluble in dilute mineral acids.
Physikalische Eigenschaften
Calcium carbonate is a naturally occurring compound found in organisms and throughout the earth’s crust. After quartz, calcium carbonate, primarily in the form of calcite, is the most common mineral found in the crust. Geologically, calcium carbonate exists in several mineral forms: calcite, aragonite, and vaterite. Calcite is the most common calcium carbonate mineral, whereas vaterite is a very rare form. The different mineral forms of calcium carbonate are based on their crystalline structure. The form of calcium carbonate depends on the conditions at its formation such as temperature and pressure.
Occurrence
Calcium carbonate occurs in nature as limestone in various forms, such as marble, chalk, and coral. It is probably the most widely-used raw material in the chemical industry. It has numerous applications, primarily to produce cement, mortars, plasters, refractories, and glass as building materials. It also is used to produce quicklime, hydrated lime and a number of calcium compounds. It is produced either as powdered or precipitated calcium carbonate. The latter consists of finer particles of greater purity and more uniform size. They also have many important commercial applications. Various grades of precipitated calcium carbonate are used in several products, such as textiles, papers, paints, plastics, adhesives, sealants, and cosmetics.
Verwenden
Calcium Carbonate is the calcium salt of carbonic acid which is
used as an anticaking agent and dough strengthener. it is available
in varying particle sizes ranging from coarse to fine powder. it is
practically insoluble in water and alcohol, but the presence of any
ammonium salt or carbon dioxide increases its solubility while the
presence of any alkali hydroxide reduces its solubility. it has a ph of
9–9.5. it is the primary source of lime (calcium oxide) which is made
by heating limestone in a furnace. calcium carbonate is used as a
filler in baking powder, for calcium enrichment, as a mild buffering
agent in doughs, as a source of calcium ions in dry mix desserts, and
as a neutralizer in antacids. it is also termed limestone.
Application
Calcium carbonate is used as a very mild abrasive for hand polishing nickel, gold, silver, or plated ware, buttons, and similar materials.
Vorbereitung Methode
Calcium carbonate is obtained from natural limestone deposits. The purified compound, known as precipitated calcium carbonate, is synthesized from limestone. Limestone is calcined to calcium oxide and carbon dioxide in a kiln. The products are recombined after purification. Calcium oxide is hydrated with water to give a slurry called milk of lime, which is then carbonated by bubbling CO2 through it. The reactions involved in the process are as follows:
CaCO3 CaO + CO2
CaO + H2O Ca(OH)2
Ca(OH)2+ CO2→CaCO3+ H2O
The crystal sizes required for various commercial applications may be controlled by temperature, pH, concentrations, and mixing rate.
Calcium carbonate also may be precipitated by mixing solutions of calcium chloride and sodium carbonate.
Definition
calcium carbonate: A white solid,CaCO
3, which is only sparingly solublein water. Calcium carbonatedecomposes on heating to give calciumoxide (quicklime) and carbondioxide. It occurs naturally as theminerals calcite (rhombohedral; r.d.2.71) and aragonite (rhombic; r.d.2.93). Rocks containing calcium carbonatedissolve slowly in acidifiedrainwater (containing dissolved CO
2)to cause temporary hardness. In thelaboratory, calcium carbonate is precipitatedfrom limewater by carbondioxide. Calcium carbonate is used inmaking lime (calcium oxide) and isthe main raw material for theSolvay process.
synthetische
Calcium carbonate may also be produced by
mixing solutions of calcium chloride and sodium
carbonate. In some cases, the presence of sodium is
objectionable so that the ammonium carbonate salt is
preferable.
Reaktionen
Calcium carbonate decomposes to calcium oxide and CO2 on heating. Treatment with dilute mineral acids produces corresponding calcium salts with liberation of CO2:
CaCO3+ 2HCl →CaCl2+ H2O + CO2
In the presence of CO2 it dissolves in water with the formation of bicarbonate:
CaCO3+ H2O + CO2→Ca2++ 2HCO3 ¯
It is reduced to calcium carbide when heated with coke or anthracite in an electric furnace:
2CaCO3+ 5C→(high temperature)→2CaC2+ 3CO2
Allgemeine Beschreibung
Calcium Carbonate (CaCO
3) is a naturally found material in chalk, limestone, and marble. It is composed of three elements which include carbon, oxygen, and calcium. It is formed by reacting carbon dioxide with slaked or burnt lime. It can be used for a variety of applications ranging from industrial, food to agriculture.
Pharmazeutische Anwendungen
Calcium carbonate (CaCO
3) can be found in clinical applications such as antacids, but not that an excessive intake can be hazardous.
A variety of calcium salts are used for clinical application, including calcium carbonate, calcium chloride,
calcium phosphate, calcium lactate, calcium aspartate and calcium gluconate. Calcium carbonate is the most
common and least expensive calcium supplement. It can be difficult to digest and may cause gas in some
people because of the reaction of stomach HCl with the carbonate and the subsequent production of CO
2.
Calcium carbonate is recommended to be taken with food, and the absorption rate in the intestine depends
on the pH levels. Taking magnesium salts with it can help prevent constipation. Calcium carbonate consists
of 40% Ca
2+, which means that 1000 mg of the salt contains around 400 mg of Ca
2+. Often, labels will only
indicate the amount of Ca
2+ present in each tablet and not the amount of calcium carbonate.
Landwirtschaftliche Anwendung
Calcium carbonate (CaCO
3) is a naturally occurring
white solid that is sparingly soluble in water. It is most
commonly used to neutralize soil acidity to the required
level in a process called liming.
The major sources of calcium carbonate are calcitic
limestone, dolomitic limestone, marl, chalk and marble.
Calcium carbonate is made by passing carbon dioxide
(CO
2) into limewater. Pure calcium carbonate is assumed
to have a 100% neutralizing value. The values of other
liming materials are measured against the neutralizing
value of pure calcium carbonate. Calcium carbonate, on
heating, decomposes to give calcium oxide (quick lime)
and carbon dioxide.
Limestone, which consists mainly of calcium
carbonate, is called calcitic limestone or high calcium
limestone. Limestone containing more than 10%
magnesium carbonate is called dolomitic limestone or
dolomite. These forms contain about 12% magnesium.
Agricultural dolomitic limestone is a fine, grey to white
powder of a double carbonate of calcium and magnesium
with 12.8% magnesium and 17% calcium. The double
carbonate is much less soluble in water than the
individual carbonates.
Sicherheit(Safety)
Calcium carbonate is mainly used in oral pharmaceutical formulations
and is generally regarded as a nontoxic material. However,
calcium carbonate administered orally may cause constipation and
flatulence. Consumption of large quantities (4–60 g daily) may also
result in hypercalcemia or renal impairment. Therapeutically, oral
doses of up to about 1.5 g are employed as an antacid. In the
treatment of hyperphosphatemia in patients with chronic renal
failure, oral daily doses of 2.5–17 g have been used. Calcium
carbonate may interfere with the absorption of other drugs from the
gastrointestinal tract if administered concomitantly.
LD
50 (rat, oral): 6.45 g/kg
Lager
Calcium carbonate is stable and should be stored in a well-closed
container in a cool, dry place.
Structure and conformation
The space lattice of CaCO3 belongs to the triagonal system, and the sodium nitric acid structure has a space group of D
63d. It isarhombohedron crystal, with a basis comprising two molecules, and it has a lattice constant of a=0.636 nm, a=46°6'. Ca
1 positions (1/4, 1/4, 1/4), Ca
2 (3/4, 3/4, 3/4), C
3 (0, 0, 0) and C
4 (1/2, 1/2, 1/2), andCtakes the middle of Ca–Ca. The O atom positions the corner of the triangle, the plane of which is perpendicular to the optical axis, Ca–C–Ca–. This includes C and O3, as C4 shift position by 60° with the O3 of C3. The behavior of CO 2K 3 is different for light oscillating perpendicularly to the optical axis (O-ray) and light oscillating parallel to the axis (E-ray), which is the origin of the uniaxial negative crystal.
Inkompatibilitäten
Incompatible with acids and ammonium salts.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (buccal chewing
gum, oral capsules and tablets; otic solutions; respiratory inhalation
solutions). Included in nonparenteral medicines licensed in the UK.
Included in the Canadian List of Acceptable Non-medicinal
Ingredients.
Calciumcarbonat Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
Styrene-acrylic latex paint for exterior wall
Calcium nitrate tetrahydrate
1,3-Diphenylaceton
Dinatrium-4-amino-3-[[4'-[(2,4-diaminophenyl)azo][1,1'-biphenyl]-4-yl]azo]-5-hydroxy-6-(phenylazo)naphthalin-2,7-disulfonat
Calciumdiformiat
Calciumbis(2-(1-carboxylatoethoxy)-1-methyl-2-oxoethyl)distearat
latex paint
Calciumdihexa-2,4-dienoat
4-(3-BROMOPHENYL)MORPHOLINE
2-Hydroxy-4-methylbenzolsulfonsure
Toothpaste
Acrylic latex paint for interior wall
Acrylic latex paint for exterior wall
Polysulfide sealant
Calciumbromid
DL-Apfelsure
Calciumnitrat
Polymyxin B, N-Sulfomethylderivat, Natriumsalz
Plastic products
Wollastonit (Ca(SiO3))
Calciumdipropionat
7-Aminonaphthalin-1,3,5-trisulfonsure
Strontiumsulfat
Natriumnaphthalin-2-sulfonat
4-Anilino-3-nitro-N-phenylbenzolsulfonamid
bastnasite
N-(4,6-DIMETHYLPYRIMIDIN-2-YL)BENZENE-1,4-DIAMINE
FORTIMICIN
Tricalciumdicitrat
Interior wall coating
(4-(4-Aminophenyl)(4-iminocyclohexa-2,5-dienyliden)methyl)-2-methylanilinhydrochlorid
Flour improver
Chrom-tin-Pink Stannite Pigment
9-Formyl-8-hydroxy-1,1,7,7-tetramethyljulolidine
CALCIUM GLUCONATE MONOHYDRATE
Cycloserin
Butan-1,2,4-triol
1-Hydroxybutan-2-on
Dinatrium-7-hydroxy-8-[[4-[1-[4-[(4-hydroxyphenyl)azo]phenyl]cyclohexyl]phenyl]azo]naphthalin-1,3-disulfonat
4,4`-di(a-methylbenzyl)diphenylamine
