Aluminium Sulfate

Product NameAluminium Sulfate
CAS10043-01-3
MFAl2O12S3
MW342.15
EINECS233-135-0
MOL File10043-01-3.mol

Chemical Properties

Melting point	770 °C (dec.) (lit.)
Boiling point	759.71°C (estimate)
Density	2.71 g/mL at 25 °C (lit.)
vapor pressure	0-0.001Pa at 20-25℃
solubility	Soluble in cold water, freely soluble in hot water, practically insoluble in ethanol (96 per cent).
pka	3.6[at 20 ℃]
form	Powder and/or Chunks
color	White
Specific Gravity	2.71
Odor	at 100.00?%. odorless
Water Solubility	soluble
Sensitive	Hygroscopic
Merck	14,366
Dielectric constant	2.6（Ambient）
Exposure limits	NIOSH: TWA 2 mg/m3
LogP	-5.08--0.12 at 20℃
CAS DataBase Reference	10043-01-3(CAS DataBase Reference)
EPA Substance Registry System	Aluminum sulfate (10043-01-3)

Safety Information

Hazard Codes	Xi,N
Risk Statements	37/38-41-51/53-36/37/38
Safety Statements	26-39-61-37/39-29
RIDADR	UN 1760/3077
WGK Germany	1
RTECS	BD1700000
TSCA	Yes
HS Code	28332200
Hazardous Substances Data	10043-01-3(Hazardous Substances Data)
Toxicity	guinea pig,LD50,unreported,490mg/kg (490mg/kg),Gigiena i Sanitariya. For English translation, see HYSAAV. Vol. 43(4), Pg. 12, 1978.

MSDS

Provider	Language
Aluminium sulfate	English
SigmaAldrich	English
ACROS	English
ALFA	English

Usage And Synthesis

Chemical Properties

Aluminium sulfate is a colorless or white crystals. Odorless, slightly sweet taste. Because of containing iron etc, industrial product looks like a yellowish-green, tastes sour. It was Stable in the air, heated to 250 ℃ to lose crystal water, when heated above 700 ℃, begin decompose into aluminum oxide, sulfur trioxide and water vapor, etc. Soluble in water, aqueous solution is acidic.

Aluminium Sulfate.png

Uses

Aluminium sulfate is soluble in water and is mainly used as a coagulating agent (promoting particle collision by neutralizing charge) in the purification of drinking water and wastewater treatment plants, and also in paper manufacturing.

Production Methods

Aluminium sulfate may be made by adding aluminium hydroxide, Al(OH)3, to sulfuric acid, H2SO4:

2 Al(OH)3 + 3 H2SO4 → Al2(SO4)3 + 6 H2O

or by heating aluminium metal in a sulfuric acid solution

2 Al + 3 H2SO4 → Al2(SO4)3 + 3 H2↑

Health Hazard

ADI not specified (FAO/WHO, 2001).

GRAS (FDA, §182.1125,2000).

LD50 6207mg/kg (mice, by mouth)

Chemical Reactivity

Aluminium sulfate reacts with sodium bicarbonate to which foam stabilizer has been added, producing carbon dioxide for fire-extinguishing foams:

Al2(SO4)3 + 6 NaHCO3 → 3 Na2SO4 + 2 Al(OH)3 + 6 CO2

The carbon dioxide is trapped by the foam stabilizer and creates a thick foam which will float on top of hydrocarbon fuels and seal off access to atmospheric oxygen, smothering the fire.

Toxicity

ADI not specified (FAO/WHO, 2001). GRAS (FDA, §182.1125,2000).

LD50 6207mg/kg (mice, by mouth)

Toxic to aquatic life

Source

Aluminium sulfate occurs in nature in minerals; alunite, KAl3(SO4)2(OH)6and natroalunite, NaAl3(SO4)2(OH)6. The anhydrous salt is used in food applications.