Transcript Bez tytułu slajdu - Politechnika Wrocławska

Magnetic separation
Principle of magnetic separation
nadawa
Utilized feature:
magnetic
susceptibility
N
S
odpad
koncentrat
In vacuum:
B0 = 0 H
0 – magnetic permeability of vacuum (410–7 V·s/(A·m) = H/m
H - magnetic field intensity (A/m)
B0 - magnetic induction in vacuum (V·s/m2 = T)
In any medium (e.g. particle):
B=H
B = 0 (H + M) = B0 + 0 M
particle input
vacuum imput
Vector of magnetic induction B in a particle is difefrent from
that of in vacuum. Therefore:
 = (B – B0)/B0 = ( – 0)/ 0 = 0M/B0
 is the volumetric dimensionless magnetic susceptibility
MATERIALS
+
paramagnetics
-
diamagnetics
Ways of expressing magnetic susceptibility

volume
w= /
mass (specific)
(dimensionless)
(cm3/g)
M = w M
molar
(cm3/mol)
feed
H y

H x
H z 

Fx  0  w m  H x
 Hy
 Hz
x
x
x 

N
H x 

generally: Fx   0  w m H x x 
S
concentrate
tailing
Classification of materials
ferromagnetics
magnetisation, M
ferri- and antyferromagnetics
true paramagnetics
0
diamagnetics
magnetic field, H
Influence of temperature
magnetic susceptibility
ferromagnetics
paramagnetics
Curie point
Néel point
antyferromagnetics
diamagnetics
temperature
Diamagnetics
Table 8.3. Specific magnetic susceptibility of diamagnetic materials
(293 K, after Hopstock, 1985)
Mineral
and its chemical formula
Diamond, C
Graphite, C
Sulfur, -S
Copper, Cu
Sphalerite, ZnS
Molibdenite, MoS2
Argentite, Ag2S
Water (ice), H2O
Corundum, Al2O3
Quartz, SiO2
Halite, NaCl
Sylvite, KCl
Magnezyt, MgCO3
Kalcyt, CaCO3
Anhydryt, CaSO4
Gips, CaSO4·2H2O
Smitsonit, ZnSO4
Mineral
– M(10–6 cm3/g)
and its chemical formula
(SI)
Elements
6,17
Silver, Ag
44
Gold, Au
6,09
Bismuth, Bi
1,08
Sulfides
3,27
Stibnite, Sb2S3
6,05
Cinnabar, HgS
3,71
Galena, PbS
Oxides
9,07
Cuprite, Cu2O
3,80
Zincite, ZnO
6,20
Cassiterite, SnO2
Halogens
6,49
Fluoryt, CaF2
6,54
Carbonates
4,83
Cerusyt, PbCO3
4,80
Sulfates
4,47
Baryt, BaSO4
5,33
Anglezyt, PbSO4
3,41
– M(10–6 cm3/g)
(SI)
2,41
1,79
16,8
3,17
2,99
4,40
1,76
4,29
2,33
4,51
2,88
3,84
2,89
Paramagnetics
-true paramagnetics
-antyferromagnetics
-ferrimagnetics
-ferromagnetics
True paramagnetics
Table 8.5. Magnetic susceptibility of selected true parmagnetics at room temperature
Paramagnetic
FeCO3
CuSO4·5H2O
FeSO4
NiSO4·7H2O
MnO
CoS
Susceptibility, w (SI)
cm3/g*
1000 200·10–6
76,7·10–6
844·10–6
201·10–6
860·10–6
2827·10–6
* w after Svoboda (1986/87).
**  M after CRC (1987).
Paramagnetic
UO2
KMnO4
Pt
NiS
MoO3
Al
Susceptibility,  M (SI)
cm3/mol**
29657·10–6
251,3·10–6
2537·10–6
2388·10–6
37,7·10–6
207,3·10–6
Antyferromagnetyki
Table 8.6. Selected antyferromagnetics and their Néel point (temperature)  N, when they become true paramagnetics having
constant magnetic susceptibility  at a given temp. and obeying the Curie–Weissa equation  = C/(T + p))
(after CRC, 1986/87)
Antyferromagnetic
Hematite, Fe2O3
Bunsenite, NiO
Pirrhotite, FeS*
Cr2O3
Tenorite, CuO
Alabandite, MnS
Pirolusite, MnO2
Ilmenite, FeTiO3
Siderite, FeCO3
 M(cgs)
–6
3586·10 (1033 K)
–
–6
1074·10 (293 K)
1960·10–6 (300 K)
238,6·10–6 (289 K)
3850·10–6 (293 K)
2280·10–6 (293 K)
11300·10–6 (293 K)
 N (K)
 p (K), dla T >  N
950
533–650
613
318
230
165
84
68
57
2000
~2000
857
–
–
528
–
–
–
* FeS is a bertolid (non-stoichiometric) compound and its properties depend on composition. FeS1,10 and FeS1,14 is a ferrimagnetic
Ferrimagnetyki
Table 8.7. Magnetic susceptability of ferrimagnetic magnetite
as a function of field intensity
(after Svoboda, 1986/87)
Intensity of
magnetic field
H, kA/m
2
4
8
16
24
32
48
Specific (mass)
magnetic susceptibility,
w (SI), cm3/g
Magnetite
1,40
1,65
2,75
2,25
1,80
1,53
1,11
Ferromagnetics
Table 8.8. Selected ferromagnetic materials with significant remanence (Br)
and energy product (BH)
Material
Alnico 12 (13,5Ni; 8Al; 24,5Co; 2Nb)
PrCo5
NdCo5
Sm(Co0,65Fe0,28Cu0,05Zr0,02)7,7
Fe; 23Cr; 15Co; 3V; 2Ti
Br
(Tesla)
1,20
1,20
1,22
1,20
1,35
(BH)max
(kJ·m–3)
76,8
286
295
264
44
a – domeins orientation
b – decreasing field
c – hysteresis
B
b
magnetic induction , B
+Br
a
c
-H
H
-Hc
+H c
c
-Br
field intensity, H
+H
Paramagnetyk
Getyt, FeOOH
Hausmanit, Mn3O4
Ilmenit, (Fe, Mn)TiO3
Limonit, Fe2O3 .H2O
Podatność
w (SI), cm3/g
250–380·10–6
500–760·10–6
200–1500·10–6
250–760·10–6
Paramagnetyk
malachit, Cu2(OH)2CO3
monacyt, (Ce,La,Dy)PO4
syderyt, FeCO3
wolframit, (MnFe)WO4
Podatność
w (SI), cm3/g
100–200·10–6
120–250·10–6
380–1500·10–6
380–1200·10–6
Feed
N
S
N
S N
S
N
S
Nonmagnetic
Magnetic
dry separation
drum separator
Feed
permanent magnets
Magnetic
Nonmagnetic
Wet separation
(drum separator)
Magnetic separation
Feed
Drum with easy and
difficult to magnetise
discs (IIIIII)
N
S
Magnetic
Induction type separator
Nonmagnetic
Semiproduct
Feed
Magnetic
Nonmagnetic
Semiproduct
belt type separator
Feed
Nonmagnetic
Magnetic
cross-belt separator
Feed
Kriostat
Magnet
Magnet
Nonmagnetic
Supercoducting
Magnetic
Cycle I
Cycle II
Feed
Water
Filling
N
S
Magnetic
particles
Nonmagnetic
particles
Magnetic
particles
HGMS, peridical
Washing off
magnetic
particles
Washing off
semiproduct
Feed
Magnet yoke
Magnet coil
Feed
Nonmagnetic
Separating
compartment
HGMS, continueous
Coils
Isodynamic filed
H dH/dx = const.
Magnetic particle
Tray with particles
Vertic
al
Fw =
F g sin 

Horizo
ntal
ISD
Fm
Fg
Fm = Fw
mgsin  =  o wm H dH /dx