Aluminium Sulfate CAS#7784-31-8
High Water Solubility – Easily dissolves in water, making it convenient for various aqueous applications.
Chemical Stability – Remains stable in water and does not dissolve in ethanol or pure sulfuric acid.
Controlled Hydrolysis – Slowly hydrolyzes in aqueous solutions, allowing for gradual reactivity when needed.
Thermal Decomposition – Decomposes predictably at high temperatures (around 770°C) into useful byproducts like aluminium oxide, sulfur trioxide, and sulfur dioxide.
Aluminum sulfate is readily soluble in water but insoluble in ethanol. It does not dissolve in pure sulfuric acid and undergoes slow hydrolysis in aqueous solutions. When heated to 770°C, it decomposes into aluminum oxide, sulfur trioxide, sulfur dioxide, and water vapor.
Aluminium sulfate octadecahydrate Chemical Properties
Melting point | 86 °C |
Density | 1,69 g/cm3 |
Bulk density | 820kg/m3 |
Storage temp | Sealed in dry,Room Temperature |
Solubility | 364g/l |
Form | Powder/Solid |
Color | White |
Specific Gravity | 1.69 |
PH Range | 3 - 4 |
PH | 2.5-4.0 (20g/l, H2O, 20℃) |
Water Solubility | Soluble |
Sensitive | moisture sensitive |
InChI | InChI=1S/2Al.3H2O4S.18H2O/c;;3*1-5(2,3)4;;;;;;;;;;;;;;;;;;/h;;3*(H2,1,2,3,4);18*1H2/q2*+3;;;;;;;;;;;;;;;;;;;;;/p-6 |
InChIKey | AMVQGJHFDJVOOB-UHFFFAOYSA-H |
SMILES | S([O-])([O-])(=O)=O.S([O-])([O-])(=O)=O.S([O-])([O-])(=O)=O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.[Al+3].[Al+3] |
CAS DataBase Reference | 7784-31-8(CAS DataBase Reference) |
EPA Substance Registry System | Sulfuric acid, aluminum salt (3:2), octadecahydrate (7784-31-8) |
Safety Information
Hazard Codes | N-Xn,Xi,N,Xn |
Risk Statements | 51/53-41-36/37/38-22 |
Safety Statements | 61-37/39-29-26-39 |
RIDADR | UN3260 - class 8 - PG 3 - RQ - Corrosive solid, acidic, inorganic, n.o.s., HI: all |
WGK Germany | 1 |
RTECS | WS5697000 |
HS Code | 2833 22 00 |
Toxicity | LD50 orally in Rabbit: > 5000 mg/kg |
Product Usage
Aluminum sulfate is widely used in the paper industry. In its acidic form, with a slight excess of H₂SO₄, it controls the pH of pulp slurries, treats process waters, sets dyes, and precipitates dissolved resin to fix sizing on fibers. In a slightly basic form, with a slight excess of Al₂O₃, it is applied in drinking and wastewater treatment, such as reducing phosphorus content. Other key applications include dyeing, tanning, acting as a catalyst, modifying concrete, and serving as a raw material in the production of various chemicals and pharmaceutical products.
