▸ processconvert
Salts & brines

Aluminium sulfate · Al2(SO4)3

Aluminium sulfate (Al2(SO4)3) is a salt; this page gives computed density for aqueous solutions from 2–24 wt% and 15–60 °C.

Values are computed from the Laliberté (2009) aqueous-electrolyte correlation and tabulated over 2–24 wt% and 15–60 °C.

Also known as
Alum, Filter alum, Papermaker's alum
CAS number
10043-01-3
Tabulated range
2–24 wt% · 15–60 °C
Properties
Density · Specific gravity
At 20 wt% · 20 °C
reference snapshot
Density
1225.7kg/m³
Density
1.2257g/cm³
Specific gravity
1.228
Explore

Read a value at any point

Move the sliders to interpolate between the tabulated grid points. The readout and chart never go outside the validated 2–24 wt% and 15–60 °C range, and every number is interpolated from the committed table below — nothing is computed from a chemistry model in your browser.

Interactive explorer

Values are interpolated between the tabulated grid points below — sliders stay within the validated 2–24 wt% and 15–60 °C range.

13 wt%
20 °C
Density
1139.3 kg/m³
Density
1.1393 g/cm³
Specific gravity
1.141
Density (kg/m³) vs wt% Al2(SO4)3 at 20 °C — Aluminium sulfate.
Why it matters

What the numbers tell you

At 20 wt% and 20 °C, aqueous aluminium sulfate has a density of about 1226 kg/m³ (1.226 g/cm³) — roughly 1.23× the density of water. That difference carries straight into volume-to-mass conversions and pump and pipe sizing.

Common grades

A few working strengths

Properties at 20 °C for a handful of concentrations in everyday use, read from the committed grid (interpolated between tabulated points where a grade falls between them). The full table follows below.

wt% Al2(SO4)3°CDensity kg/m³SG
4201038.81.041
8201081.91.084
16201175.41.178
24201278.21.281
Sources

Where the numbers come from

Every value on this page is computed by a deterministic model — none is entered by hand. The generating method and the references it is checked against:

  • ▸Laliberte, M. (2009). A Model for Calculating the Heat Capacity of Aqueous Solutions, with Updated Density and Viscosity Data. J. Chem. Eng. Data 54(6), 1725-1760. doi:10.1021/je8008123
  • ▸Perry's Chemical Engineers' Handbook, 7th ed. (Perry & Green) - Table 2-33 Aluminum Sulfate density, from International Critical Tables, Vol. III, p. 70
  • ▸CRC Handbook of Chemistry and Physics - Aqueous Solubility of Inorganic Compounds at Various Temperatures (solubility bounds for the tabulated range)

Model: thermo==0.4.0 (chemicals==1.3.0) - Laliberte 2009 electrolyte correlation · Generated 2026-06-07

The committed data file for this page is published as JSON on GitHub under CC BY 4.0.

Validation

Checked against a cited value

The model is cross-checked at one independently cited reference point. The page is published only because this check passes.

Property / pointDensity · 20 wt% · 15 °C
Cited reference value1227.2 kg/m3
Model computed1227.74 kg/m3
Error vs reference0.044% (tolerance 1%)

Perry's Chemical Engineers' Handbook, 7th ed. (from International Critical Tables). Perry, R.H. & Green, D.W. (eds.), Perry's Chemical Engineers' Handbook, 7th ed., Table 2-33 Aluminum Sulfate [Al2(SO4)3] (data from International Critical Tables, Vol. III, p. 70): 20 wt% Al2(SO4)3 (anhydrous basis), d15/4 = 1.2272 g/cm3. The 15 degC basis is the source table's reference temperature; the check is evaluated at 15 degC, inside the tabulated range.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% Al2(SO4)3). Read the cell at the intersection. Specific gravity is density divided by the model water reference of 998.2 kg/m³ at 20 °C.

Density — kg/m³
°C \ wt%24681012141618202224
151019.21039.91061.31083.21105.81129.01152.81177.21202.21227.71253.91280.5
201018.21038.81060.11081.91104.31127.41151.11175.41200.21225.71251.71278.2
251017.01037.51058.61080.31102.61125.61149.11173.31198.11223.51249.41275.8
301015.51035.91056.91078.51100.71123.51147.01171.11195.81221.01246.81273.2
351013.71034.01054.91076.51098.61121.31144.71168.71193.21218.41244.11270.4
401011.81032.01052.81074.21096.31118.91142.21166.01190.51215.61241.31267.5
451009.71029.81050.51071.81093.81116.31139.51163.31187.71212.71238.31264.5
501007.51027.51048.11069.31091.11113.61136.71160.41184.71209.71235.21261.3
551005.01024.91045.51066.61088.31110.71133.71157.31181.61206.51232.01258.1
601002.41022.31042.71063.71085.41107.71130.61154.21178.41203.21228.61254.7
Typical values

Aluminium sulfate solution properties at 25 °C

At 25 °C, 4 wt% aluminium sulfate has a density of about 1037.5 kg/m³. At 25 °C, 16 wt% aluminium sulfate has a density of about 1173.3 kg/m³. At 25 °C, 24 wt% aluminium sulfate has a density of about 1275.8 kg/m³.

Limitations

Before you use these numbers

  • ▸Laliberte (2009) aqueous-electrolyte correlation for Al2(SO4)3-water, density only. Tabulated for 2-24 wt% over 15-60 degC. Saturation is about 27-28 wt% Al2(SO4)3 over this range, so the 24 wt% ceiling sits below saturation. Viscosity and heat capacity are not tabulated: the correlation carries no heat-capacity coefficients for aluminium sulfate and its viscosity data covers only a narrow dilute band (to about 3 wt%), so both are omitted rather than approximated. Concentrations are anhydrous Al2(SO4)3; commercial liquid alum is about 48% of the hydrated salt, near 8% expressed as Al2O3. Values are for preliminary design; verify against vendor data for critical service.
  • ▸Values are tabulated only inside the 2–24 wt% and 15–60 °C ranges shown; the correlation is not extrapolated beyond them here.
  • ▸Figures are for a pure aluminium sulfate–water system. Commercial grades contain impurities (for example chloride in some caustic grades) that shift density and viscosity; check the supplier's data sheet for a specific product.
  • ▸Use for preliminary design; verify for critical service.
Related calculators
Related guides
Other substances
← All substances

Built and reviewed by a practising process engineer. About ProcessConvert →