On the surface of pyrite FeS2
there is the surface compound of ethyl xanthate of iron
Fe(C2H5OCSS)2.
The surface compound is formed as a result of chemical sorption and
it consists of ethyl xanthate anions C2H5OCSS-
and iron cations Fe2+.
Can hydroxyl ions OH-
to displace from the surface of pyrite the anions of ethyl xanthate
C2H5OCSS-
and to form the new surface compound of ferric hydroxide Fe(ОН)2
as a result of chemical sorption?
Since ΔG0 is negative, the flow of this process is thermodynamically probable. This reaction is used for the depression of pyrite by lime.
The results of the practice argue that, with the chemical sorption of xanthate, poorly soluble compound of xanthate of iron Fe(C2H5OCSS)2 is formed on the surface of pyrite. This compound can be removed from the pyrite surface only with using its displacing by the hydroxyl ions, which are actively interact with the iron cations Fe2+ to form ferric hydroxide Fe(ОН)2.
P.S. Sorption of flotation reagents at interfaces occurs spontaneously and is accompanied by a loss of free surface energy. Changing the standard free energy Gibbs ΔG0 in the sorption of flotoreagents at the interface is described by Gibbs [1].
For the thermodynamic probable processes accompanied by energy loss, the value of Gibbs free energy ΔG0 should have a negative value.
Since ΔG0 is negative, the flow of this process is thermodynamically probable. This reaction is used for the depression of pyrite by lime.
The results of the practice argue that, with the chemical sorption of xanthate, poorly soluble compound of xanthate of iron Fe(C2H5OCSS)2 is formed on the surface of pyrite. This compound can be removed from the pyrite surface only with using its displacing by the hydroxyl ions, which are actively interact with the iron cations Fe2+ to form ferric hydroxide Fe(ОН)2.
P.S. Sorption of flotation reagents at interfaces occurs spontaneously and is accompanied by a loss of free surface energy. Changing the standard free energy Gibbs ΔG0 in the sorption of flotoreagents at the interface is described by Gibbs [1].
For the thermodynamic probable processes accompanied by energy loss, the value of Gibbs free energy ΔG0 should have a negative value.
- FUNDAMENTALS OF THE THEORY OF FLOTATION
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