AlPrg shows on the Electrolyte Properties Page [Lit.] several physical and chemical properties of the electrolytic bath. AlPrg determines these values in dependence of the electrolyte composition and the electrolyte temperature. For several properties you select the authors of the mathematical relation to determine the wanted property.

Electrolyte Composition

AlPrg describes the composition of the electrolyte according to the AlPrg Standard System, i.e. the bath consists of cryolite (Na₃AlF₆) with additions of aluminum fluoride (AlF₃), calcium fluoride (CaF₂), aluminum oxide (alumina Al₂O₃), etc. You may change also the bath ratio by clicking into the input field and changing the value (with the mouse wheel, for instance).
Aluminum Oxide of the Anode Effect means the limiting value of the aluminum oxide concentration that AlPrg uses to fire an Anode Effect.
If you want to calculate the electrolyte properties of cryolite (i.e. the concentration of all additions is zero) you click on the checkbox and the input field of the alumina concentration at the anode effect is grayed i.e.. e. becomes inactive. Now you can set the alumina content to any value ≥ 0 %.

Electrolyte Properties of Cryolite at its Melting Point

Remark:
You can inactivate the input field of the aluminum oxide concentration at the anode effect only if all Cell Voltage Pages (Cell Geometry, Bath Voltage, Energy Balance etc.) are closed.

Electrolyte Temperature and Superheat

The electrolyte (bath) temperature and the superheat (difference between the bath temperature and the liquidus temperature) are also input values. If the superheat is an input value (activated input field in the figure above) AlPrg determines the electrolyte temperature (inactivated input field) i.e. the bath temperature changes with the liquidus temperature.
If you click on the electrolyte temperature input field it becomes activated i.e. the bath temperature is now an input value and AlPrg calculates the superheat.

Liquidus Temperature

AlPrg calculates the liquidus temperature by using the relations given the Theory Chapter about the Liquidus Temperature. You select the wanted equations by using the Liquidus Temperature Combo Box.

You may want to open the Liquidus Temperature Diagrams Window that shows among other things the dependence of the liquidus temperature on the electrolyte composition and the bath temperature. Conceived as a GUI (Graphical User Interface) you change the composition or temperature values by dragging action with the mouse pointer.

Electrical Conductivity

In a similar way AlPrg calculates the electrical conductivity of the electrolyte by using the relations given the Theory Chapter about the Electrical Conductivity. You select the wanted equations by using the Electrical Conductivity Combo Box (see the Electrical Conductivity Diagram Window).

Maximal Alumina Solubility

When alumina is added to a bath saturated with alumina i.e. the alumina concentration has reached the maximal solubility value the alumina will not dissolve in the electrolyte. This undissolved alumina settles at the bottom of the electrolytic cell under the aluminum pad and forms the so-called bottom sludge. Sludge consists of loosely packed alumina packed grains where the voids are filled with electrolyte.
The Electrolyte Properties Page shows the Maximal Alumina Solubility value that AlPrg calculates according to the relation given in the Theory Chapter. 

Densities

The densities values of liquid aluminum and of the molten cryolite electrolyte are essential, for instance, for the magnetohydrodynamic behavior of the aluminum pad under the electrolyte layer. The density difference of the two liquids should be large enough to assure good separation of the aluminum metal pad from the bath layer (see Densities Diagram).
You may select one of several relations to determine the aluminum density (see Aluminum Density in the Theory Chapter)

as you can do for the density of the liquid bath (see Electrolyte Density in the Theory Chapter)

Total Vapor Pressure

The vapor phase of the liquid cryolite electrolyte contains several species, sodium fluoride (NaF) or sodium aluminum fluoride (NaAlF₄), for instance. AlPrg calculates the total and partial pressure of these species. These values determine among other things the fluorine evolution of the electrolytic cell.
The Electrolyte Properties Page shows the value of the total vapor pressure that AlPrg determines according to the relation in the corresponding Theory Chapter.

Viscosities

The visosity values of the liquid aluminum phase and the molten bath affect the movement of metal droplets in the electrolyte, the dissolution and sedimentation of alumina particles and the release of the gas bubbles from the anode surface. The Electrolyte Properties Page shows the value of the viscosities of liquid aluminum and of the electrolyte. AlPrg calculates these values using the relations in the Viscosity Theory Chapter.