TITLE:
Synthesis and Structural Characterization of Xanthate (KEX) in Sight of Their Utilization in the Processe s of Sulphides Flotation
AUTHORS:
Nedjar. Zohir, Bouhenguel. Mustapha, Djebaili Abd Elbaki
KEYWORDS:
Flotation; Synthesis; Xanthate (KEX); Adsorption; Galena
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.8 No.6,
June
20,
2009
ABSTRACT: A lot of industries (chemical, mining) developed numerous processes based on the use of the
adsorption, From then on, the resolution of practice problems pass inevitably by the
understanding of fundamental concepts governing the phenomena of flotation and the interaction
in the solid- liquid or solid - gas interface.
In this study, we suggest proceeding to a theoretical and experimental study concerning the
organic synthesis of an organo metallic product (KEX) by intermittent method and their use in
the processes of sulphides flotation. Searches showed that the surface state after grinding
resulted from a combination of oxidized sorts of sulfur treat type with copper sulphate and lead
oxy-hydroxide thickness of which is very superior to 200 nm. The addition of an organometallic
molecule sulphurated (Potassium ethyl xanthate KEX) in available concentrations of 1g/l (6,
24.10-3 M) is going to lead the forming of an organometallic layer mixed in the galena surface.
From weak concentrations in collector, the organometallic layer present in the mineral surface
is mixed. It is formed by a complex xanthate type of lead (PbX, bandages IR in 1200 cm-1), of
dixanthogene (X2 forms oxidized with the molecule of xanthate, bandages IR in 1262 cm-1), of
elementary sulfur and a certain proportion of initial superficial oxidized phases. The mechanism
leading to the forming of PbX is the type of ionic exchanges. On the other hand, two types of
different mechanisms can be at the origin of dixanthogene forming (X2).
A first type consists of a catalytic oxidation in the mineral surface with reduction of the dissolved
oxygen. This type of mechanism depends essentially on the potential redox of the system. A
second type brings in the forming of xanthate salts of lead by a mechanism of Ionic exchange
(eq. 1) then their catalytic degradation (eq. 2):
Pbn + + n X- → (Pb X) n Equation 1: independent from the potential rédox.
Pb(X) n (catal. by PbS) + 1/2 O2 + n/2 H2O → Pb (OH) n + n/2 X2 Equation 2: dependent on
the redox potential.