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SLIME COATING AND COAGULATION
adhesion of particles or particles to surfaces
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Slime coating
AFM-images of slime coatings on mineral surface
M.E. Holuszko et al., Minerals Engineering, 21,
2008, 958-966
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Slime coating
Very important phenomenon
Can be useful and harmful
Ferric oxide slime and flotation of quartz with
10-4 M dodecyl ammonium acetate
Chemistry of flotation , M.C. Fuerstenau, J.D.
Miller, M.C. Kuhn, AIMM, 1985
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Alumina as slime on galena and flotation with
xanthate
Chemistry of flotation , M.C. Fuerstenau, J.D.
Miller, M.C. Kuhn, AIMM, 1985
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coagulation
homocoagulation
heterocoagulation
main parameter stability ratio W
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Process delineation (thermodynamics)
?Gk Gh G? 
?Gk  ?Gk d ?Gk el ?Gk s  ?Gk inne
That is components dispersion (d), electrical
(el), structural (s), a others
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Dispersion interactions
H distance between particles, m R diameter
of particle, m A132 Hamaker constant, J
phase 1
phase 2
phase 3
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Dispersion interaction
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Hamaker constant
Dispersion interaction
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Dispersion interaction

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Electrostatic interaction
?1 particle electrostatic potential, V, ?2
the other particle electrostatic potential, V,
R1 particle radius, m, R2 the other
particle radius, m, ? dielectric constant
(usually water) ?0 dielectric permeability in
vacuum, 8,8541878171012 C2 N1 m2 1/? Debye
radius (thickness of ewp), m, H
distance between interacting objects, m.
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Electrostatic interaction
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Structural interaction
For flat particles
For spherical particles
K , K , Eso- constants l - parameter
correlating standing for thickness of oriented
water molecules at the surface of particle H -
distance between particles R - radius of
particles
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Total interaction
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Total interaction
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Stability ratio W
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Time of half-life t1/2 of hypothetical emulsion
containing 1 ?m droplet and having energy
barrier Vmax one radius apart from the droplet
surface (after Friberg, 1991)
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Main parameter stability ratio W
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selective coagulation
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selective coagulation
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selective coagulation