Click on Download
Equilib Regular Slide Show (pdf presentation - 102
pages) for detailed information on the regular features
of the Equilib Module.
Click on Download
Equilib Advanced Slide Show (pdf presentation - 115
pages) for detailed information on the advanced features
of the Equilib Module.
module is the Gibbs energy minimization workhorse of FactSage
and the most popular program. It calculates the concentrations
of chemical species when specified elements or compounds
react or partially react to reach a state of chemical
equilibrium. In most cases the user makes three entries
as shown in the Equilib
Reactants Window (Fig. 2) and Menu Window
the reactants, then click on ‘Next >>’.
the possible compound and solution products.
the final conditions - T and P, or other constraints,
then click on ‘Calculate >>’.
Reactants Window (Fig. 2) shows the entry for
a copper-based pyrometallugical system (variable amounts
<A> of FeO, <75A – B> of SiO2,
and <B> of CaO, with fixed amounts of Cu2O,
Fe2O3, Pb, Zn, Cu and Cu2S).
the Menu Window (Fig. 3) the possible products
are identified (gas phase, pure solids and slag, spinel,
matte, copper alloy solution phases) together with a range
of composition (<A> = 40, 41, 42, ... 57), the temperature
(1250ºC) and total pressure (1 atm.). Not shown here
is how one can set various constraints, options, targets,
etc. (in the example the equilibrium partial pressure
of oxygen was fixed at P(O2) = 10-8 atm). You
then click on the “Calculate >>” button
and the computation commences.
the calculation is finished you are automatically presented
with the Results Window where Equilib
provides the equilibrium products of the reaction and
where the results may be displayed in F*A*C*T
output formats. The equilibrium product amounts are positive,
satisfy the mass balance constraints with respect to the
system components and correspond to the lowest possible
Gibbs energy for this particular selection of possible
products. For example Fig. 4 displays the results in F*A*C*T
format at <A> = 40; this equilibrium point corresponds
to silica saturation, a(SiO2) = 1.0. The equilibrium compositions
of the slag, matte and blister copper are also listed.
Fig. 5 shows a ChemSage
output format for <A> = 57 that now corresponds
to spinel saturation. The calculated values may also be
presented and manipulated via the List Window.
For example Fig. 6 shows the distribution of the elements
(Cu, Fe) among the phases when <A> = 50.
may enter up to 48 reactants consisting of up to 32 different
components (elements and electron phases). Reactants may
include “streams” - these are equilibrated
phases stored from the results of previous calculations
(useful in process simulation). Phases from the compound
and solution databases are retrieved and offered as possible
products in the Menu Window. These may include
pure substances (liquid, solid), ideal solutions (gas,
liquid, solid, aqueous) and non-ideal solutions (real
gases, slags, molten salts, mattes, ceramics, alloys,
dilute solutions, aqueous solutions, etc.) from the databases
employs the Gibbs energy minimization algorithm and thermochemical
functions of ChemSage
and offers great flexibility in the way the calculations
may be performed. For example, the following are permitted:
a choice of units (K, C, F, bar, atm, psi, J, cal, BTU,
kwh, mol, wt.%, ...); dormant phases in equilibria; equilibria
constrained with respect to T, P, V, H, S, G, U or A or
changes thereof; user-specified product activities (the
reactant amounts are then computed); user-specified compound
and solution data; and much more. Phase targeting and
one-dimensional phase mappings with automatic search for
phase transitions are possible. For example, you can calculate
all equilibrium (or Scheil-Gulliver non-equilibrium) phase
transitions as a multicomponent mixture is cooled.
offers a post-processor whereby the results may be manipulated
in a variety of ways: tabular output ordered with respect
to amount, activity, fraction or elemental distribution;
post-calculated activities; user-specified spreadsheets
of f(y) where y = T, P, V, H, S, G, U , A, Cp or species
mole, gram, activity, mass fraction and f = y, log(y),
ln(y), exp(y) etc. for Lotus 1-2-3, Microsoft Word or
Excel. For example Fig. 7 shows post-processing of the
results and the generation of a Cu wt%. vs Fe(total)/SiO2
wt.% diagram for the complete set (18) of equilibrium
calculations. Fig. 8 shows (top) a display of the thermodynamic
partial properties functions, and (bottom) a partial listing
of the calculated integral properties of a solution phase
(FACT-MATT) for all 18 calculations.