Calciumdihydroxid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE KRISTALLE ODER WEISSES PULVER.
CHEMISCHE GEFAHREN
Zersetzung beim Erhitzen unter Bildung von Calciumoxid. Mittelstarke Base in w?ssriger L?sung. Reagiert sehr heftig mit S?uren. Greift viele Metalle in Gegenwart von Wasser an unter Bildung entzündlichen/explosionsf?higen Gases (Wasserstoff, s. ICSC-Nr. 0001).
ARBEITSPLATZGRENZWERTE
TLV: 5 mg/m?(als TWA) (ACGIH 2005).
AUFNAHMEWEGE
Aufnahme in den K?rper durch Inhalation des Aerosols und durch Verschlucken.
INHALATIONSGEFAHREN
Verdampfung bei 20°C vernachl?ssigbar; eine gesundheitssch?dliche Partikelkonzentration in der Luft kann jedoch beim Dispergieren schnell erreicht werden.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt die Atemwege und ver?tzt die Augen und die Haut. ?rztliche Beobachtung notwendig.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Hautkontakt kann Dermatitis hervorrufen. Risiko der Lungensch?digung bei wiederholter oder l?ngerer Exposition gegenüber Staubpartikeln.
LECKAGE
Verschüttetes Material in Beh?ltern sammeln. An sicheren Ort bringen. Pers?nliche Schutzausrüstung: Atemschutzger?t, P2-Filter für sch?dliche Partikel.
R-S?tze Betriebsanweisung:
R41:Gefahr ernster Augensch?den.
R34:Verursacht Ver?tzungen.
S-S?tze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S39:Schutzbrille/Gesichtsschutz tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S27:Beschmutzte, getr?nkte Kleidung sofort ausziehen.
Beschreibung
Calcium Hydroxide is a colorless crystal or white powder,
obtained when CaO (called lime or quicklime) is mixed, or
“slaked” with water. It can also be precipitated by mixing
CaCl2 andNaOH.The nameof the natural,mineral formis
“portlandite”. It is a relatively rare mineral, known from
some volcanic, plutonic, and metamorphic rocks. It has
also been known to be formed in burning coal dumps.
Chemische Eigenschaften
Calcium hydroxide occurs as a white or almost white, crystalline or
granular powder. It has a bitter, alkaline taste. Calcium hydroxide
readily absorbs carbon dioxide to form calcium carbonate.
Physikalische Eigenschaften
Soft white crystalline powder; hexagonal; density 2.34 g/cm
3; slightly bitter taste; loses water when heated at elevated temperatures (580°C); slightly soluble in water; Ksp 1.2x10-
14; aqueous solution alkaline; soluble in glycerol and acids; insoluble in alcohol.
Verwenden
calcium hydroxide is an inorganic base used to adjust the pH of a product, it can also serve as a topical astringent and alkali in solutions or lotions. It can burn the skin and eyes.
Definition
Lime water: A solution of calcium hydroxide
in water. If carbon dioxide is bubbled
through lime water a milky precipitate of
calcium carbonate forms. Prolonged bubbling
of carbon dioxide turns the solution
clear again as a result of the formation of
soluble calcium hydrogencarbonate
(Ca(HCO
3)
2).
Vorbereitung Methode
Calcium hydroxide is manufactured by adding water to calcium
oxide, a process called slaking.
Allgemeine Beschreibung
Odorless white granules. Sinks in water.
Air & Water Reaktionen
Water soluble. The amount of heat generated by hydrolysis may be large.
Reaktivit?t anzeigen
The nitroparaffins, nitromethane, nitropropane, etc. form salts with inorganic bases such as Calcium hydroxide . The dry salts are explosive [Chem. Eng. news 30:2344 1952]. Bases are chemically similar to sodium hydroxide (NaOH) or sodium oxide (Na2O). They neutralize acids exothermically to form salts plus water. When soluble in water they give solutions having a pH greater than 7.0. Mixing these materials with water can generate troublesome amounts of heat as the base is dissolved or diluted. Bases react with certain metals (such as aluminum and zinc) to form oxides or hydroxides of the metal and generate gaseous hydrogen. Bases may initiate polymerization reactions in polymerizable organic compounds, especially epoxides). They may generate flammable and/or toxic gases with ammonium salts, nitrides, halogenated organics, various metals, peroxides, and hydroperoxides. Materials of this group often serve as catalysts. A strong base. Forms caustic solution in water [Merck 11th ed. 1989].
Hazard
Skin, eye, and upper respiratory tract irri-
tant, avoid inhalation.
Health Hazard
Dust irritates eyes, nose and throat.
Pharmazeutische Anwendungen
Calcium hydroxide is a strong alkali and is used as a pharmaceutical
pH adjuster/buffer and antacid in topical medicinal ointments,
creams, lotions, and suspensions, often as an aqueous solution (lime
water). It forms calcium soaps of fatty acids, which produce
water-in-oil emulsions (calamine liniment), and it is also used as a
topical astringent.
Calcium hydroxide is a common cosmetic ingredient in hairstraightening
and hair-removal products, and in shaving preparations.
1) In dentistry, it is used as a filling agent and in dental pastes
to encourage deposition of secondary dentine. Calcium hydroxide
was traditionally used as an escharotic in Vienna Paste.
Landwirtschaftliche Anwendung
Calcium hydroxide, [Ca(OH)
2], also called slaked lime
or hydrated lime, is a white solid that dissolves
sparingly in water. It is manufactured by adding water to
calcium oxide, a process that emits heat and is known as
slaking.
Calcium hydroxide is a cheap alkali, used for
neutralizing the acidity of acid soils and in the
manufacture of mortar, white wash, bleaching powder
and glass. It is an excellent absorbent for carbon dioxide
to produce insoluble calcium carbonate and has a
neutralizing value of 179%, compared to 100% of pure
calcium carbonate.
Sicherheitsprofil
Mildly toxic by
ingestion. A severe eye irritant. A skin,
mucous membrane, and respiratory system
irritant. Mutation data reported. Causes
dermatitis. Dust is considered to be a
significant industrial hazard. A common air
contaminant. Violent reaction with maleic
anhydride, nitroethane, nitromethane,
nitroparaffins, nitropropane, phosphorus.
Reaction with polychloiinated phenols +
potassium nitrate forms extremely toxic
products. See also CALCIUM
COMPOUNDS
Sicherheit(Safety)
Calcium hydroxide is used in oral and topical pharmaceutical
formulations. It is mildly toxic by ingestion. In the pure state,
calcium hydroxide is a severe skin, eye, and respiratory irritant, and
it is corrosive, causing burns. Typical exposure limits are TVL
5 mg/m
3 in air.
LD
50 (mouse, oral): 7.3 g/kg
LD
50 (rat, oral): 7.34 g/kg
m?gliche Exposition
Calcium hydroxide is used in agriculture and in fertilizer manufacture; it is used in the formulation of mortar, plasters, and cements; it is used as a
scrubbing and neutralizing agent in the chemical industry.
For making insecticides, acaricides, and products to control
arthropods
Lager
Calcium hydroxide should be stored in an airtight container, in a
cool, dry, well-ventilated place. Calcium hydroxide powder may be
sterilized by heating for 1 hour at a temperature of at least 1608℃.
Versand/Shipping
UN3262 Corrosive solid, basic, inorganic, n.o.s.,
Hazard class: 8; Labels: 8-Corrosive material, Technical
Name required
l?uterung methode
Heat analytical grade calcium carbonate at 1000o during 1hour. Allow the resulting oxide to cool and add slowly to water. Heat the suspension to boiling, cool and filter through a sintered glass funnel of medium porosity (to remove soluble alkaline impurities). Dry the solid at 110o and crush it to a uniformly fine powder. [Ehrlich in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 934 1963.]
Inkompatibilit?ten
Incompatible with strong acids, maleic anhydride, phosphorus,
nitroethane, nitromethane, nitroparaffins, and nitropropane. Calcium
hydroxide can be corrosive to some metals.
Waste disposal
Landfill or admixture with
acid industrial wastes prior to lagooning
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (intravenous and
subcutaneous injections; oral suspensions and tablets; topical
emulsions and creams). Included in parenteral preparations licensed
in the UK.
Calciumdihydroxid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
