DESCRIPTION
i
i Title of Invention
METHOD OF MANUFACTURING GRANULATED MATERIAL OF RON ORE
5 RAW MATERIAL AND GRANULATED MATERIAL OF IRON ORE RAW
MATERIAL
Technical Field
[OOO 11
10 The present invention relates to a method of manufacturing a granulated material
of iron ore raw material and a granulated material of iron ore raw material. Priority is
claimed on Japanese Patent Application No. 2010-228908, filed October 8,2010, and
Japanese Patent Application No. 201 1-178956, filed August 18,201 1, the content of
which is incorporated herein by reference.
Background Art
[0002]
As a raw material to be charged in a blast furnacein an iron-making process,
generally, a sinter obtained by adding water or a granulating agent to iron ore fines,
20 kneading the mixture so as to produce a pseudo granulated material, and sintering the
pseudo granulated material using a sintering machine is used. In the sintering process
of the sinter, there is a problem in that the pseudo granulated material causes clogging in
a sintering raw material-filled layer so as to degrade air permeability, the combustion rate
of a coke which is a fuel becomes slow, and the production efficiency of the sinter is
25 degraded. Therefore, it is an important object to obtain a granulated material having a
2 --..
favorable crushing strength so that pseudo particles that configure the pseudo granulated
material do not easily break, and favorable granulating properties. Favorable
4
granulating properties refer to the fact that the fraction of pseudo pdcles having a small
particle diameter in the pseudo particles that configure the pseudo granulated material is
small. For example, the fraction of pseudo particles having a particle diameter of less
than 0.25 rnrn is 3 mass% or less.
I [0003]
In recent years, good &ality iron ore raw materials have been being depleted.
Thereforeyit becomes a subject to use poor quality iron ore fines which includes much
fine powder or pellet feed. The pellet feed refers to cheap iron ore having an average
particle diameter of approximately several tens of pm to 100 pm for which the content of -
iron is increased by crushing and water-washing iron ore which includes a small amount
of iron. The pellet feed has a small amount of the gangue components of A1 or Si, and
therefore the merit of using a large amount of the pellet feed is significant. However,
since the pellet feed has flat ore surfaces, and rarely includes ultrafine powder of 10 pm
or less, the pellet feed is an ore that is not easily granulated, and, when being used,
impairs air permeability in a sintered layer.
In order to obtain a granulated material having favorable granulating properties, .
currently, burnt lime is widely used as a bond having a binding hnction. Burnt lime is
widely used as a bond because, when burnt lime is used, a granulated material having
favorable granulating properties is easily obtained, and the crushing strength of the
obtained pseudo particles is high so that the pseudo particles do not easily break.
However, in a case in which burnt lime is used, the effect cannot be obtained
sufficiently unless a large amount of burnt lime is used. Furthermore, even when 2
mass% or more of burnt lime is added, there is a tendency of the effect of improving
granulating properties to become saturated, which worsens cost performances.
[0004]
i,
Patent Document 1 or 2 discloses a granulating agent havingnot only a binding
function but also a function that breaks up and disperses a water-containing aggregate.
In addition, a method in which iron ore fines are sufficiently dispersed so that water
exhibits an action that efficiently granulates the iron ore fines is disclosed. Furthermore,
as a granulating agent having not only a binding function but also a function that breaks
up and disperses a water-containkg aggregate, a high molecular compound having a
carboxyl group is disclosed.
Citation List
Patent Document
[00051 .
[Patent Document 11 Japanese Unexamined Patent Application, First
Publication No. 2004-076132
[Patent Document 21 Japanese Unexamined Patent Application, First
Publication No. 2004-076133
Summary of Invention
Technical Problem
[0006]
However, in the methods disclosed in Patent Documents 1 and 2, it is not
possible to sufficiently satisfy the demand of 3% or less of the fraction of pseudo
particles having a particle diameter of less than 0.25 mm.
[0007]
The present invention provides a method of manufacturing a granulated material
of iron ore fines which exhibits excellent granulating properties even in a case in which a
\ 4
raw material that is not easily granulated such as poor quality iron or8 fines including a
large amount of powder or pellet feed is used, and the granulated material. Specifically,
5 the fraction of pseudo particles having a small particle diameter in pseudo particles that
configure a pseudo granulated material is small, and, for example, the fraction of pseudo
particles having a particle diameter of less than 0.25 mm is 3 mass% or less.
Solution to Problem
In order to solve the above problem and achieve the object, the present invention -
employs the following measures.
[0009] ,
(1) That is, a method of manufacturing a granula. te. d material of an iron ore raw
- L
15 material according to an aspect of the present invention includes a process of adding 0.01
parts by mass to 10 parts by mass of a high molecular surfactant which has a
hydrophobic group and an acidic functional group and has a molecular weight of 10000
to 30000, a total of 0.5 parts by mass or more of one or twa of CaO and Ca(OH)2 in
which the total is converted into mass of Ca(OH)2, and 3 parts by mass to 25 parts by
20 mass of water to a total amount of 100 parts by mass of the iron ore raw material
including iron ore fines.
[OO lo]
(2) In the method of manufacturing the granulated material of the iron ore raw
material according to the above (I), the iron ore raw material may be include the iron ore
25 fines and pellet feed.
5
[OO 1 11
(3) In the method of manufacturing the granulated material of the iron ore raw
\ P,
material according to the above (2), in a case in which a mass ratio bttween the iron ore
fines and the pellet feed is defined as (100-x):x, x may be from 2 to less than 90.
[OO 121
(4) In the method of manufacturing the granulated material of the iron ore raw
material according to any one of the above (1) to (3), the hydrophobic group may be at
least one kind of an alkyl group, an alkyl ester group, and an aryl group, and, in a case in
which M is defined as an alkali metal, an alkaline earth metal, or NH4, the acidic
10 functional group is at least one kind of salt represented by a carboxyl group, a sulfonic
acid group, a phosphoric acid group, a sulfate group, -COOM, -S03M, -HMP04, -MlP04,.
or -0S03M.
[0013] .
(5) In the method of manufacturing the granulated material of the iron ore raw
15 material according to the above (4), the iron ore fines may include fine particies o'f 0.25
.
mm or less, and the fraction of ultrafine particles of 10 pm or less in the fine particles
a . .
may be 20 mass% to 70 mass%.
[00 141 . .
(6) In the method of manufacturing the granulated material of the iron ore raw
20 material according to any one of the above (1) to (3), the iron ore fines may include fine
particles of 0.25 mm or less, and the fraction of ultrafine particles of 10 pm or less in the
fine particles may be 20 mass% to 70 mass%.
[00 1 51
(7) A granulated material of an iron ore raw material according to an aspect of
25 the present invention including iron ore fines, 0.0096 mass% to 9.05 mass% of a high
. -4 -- molecular surfactant which has a hydrophobic group and an acidic hnctional group and
has a molecular weight of 10000 to 30000 and 0.45 mass% or more of lime hydrate.
i
[00 1 61 S
(8) A granulated material of an iron ore raw material according to an aspect of
5 the present invention including iron ore fines and pellet feed, 0.0096 mass% to 9.05
mass% of a high molecular surfactant which has a hydrophobic group and an acidic
functional group and has a molecular weibht of 10000 to 30000 and 0.45 mass% or more
of lime hydrate.
[GO 1 71
10 (9) In the granulated material of an iron ore raw material according to the above
(8), in a case in which the mass ratio between the iron ore fines and the pellet feed is
defined as (100-x):x, x may be from 2 to less than 90.
(10) In the granulated material of an iron ore raw material according to any one
15 of the above (7) to (9), the hydrophobic group may be at least one of an alkyl group, an
alkyl ester group, and an aryl group, and, in a case in which M is defined as an alkali
metal, an alkaline earth metal, or NH4, the acidic functional group is at least one kind of
salt represented by a carboxyl group, a sulfonic acid group, a phosphoric acid group, a . .
sulfate group, -COOMY -S03M, -HMP04, -M2PO4, or -0S03M.
Advantageous Effects of Invention
[00 1 91
According to the above aspects of the present invention, it is possible to obtain a
granulated material having a small fraction of particles having a small particle diameter
25 in particles that configure the granulated material, for example, a granulated material
having a fraction of pseudo particles having a particle diameter of less than 0.25 mm of 3
mass% or less. As a result, for example, it is possible to obtain a granulated material
4
having a strength of 10 kgf7cm2 or more. It is possible to suficientl~im prove the
sintering productivity simply by substituting some of a granulated material obtained with
granulating burnt lime as a binder, which has been thus far carried out, into the
granulated material of the present invention.
Brief Description of Drawings
[GO201
FIG. 1 is a view showing a copolymer of ammonium polyacrylate, methyl
polyacrylate and the like according to an embodiment of the present invention.
FIG. 2 is a view showing a basic structure of a sulfonic acid-based
three-dimensional polymer molecule according to the embodiment of the present
invention.
FIG. 3 is a view showing a copolymer of sodium polysulfonate and ethyl
polyacrylate according to the embodiment of the present invention.
FIG. 4 is a view showing a copolymer of sodium polycarbonate and polystyrene
according to the embodiment of the present invention. .
. .
FIG. 5 is a view showing sodium polyacrylate according to the embodiment of
the present invention.
FIG. 6 is a view showing a copolymer of sodium polymaleate or polyethylene
according to the embodiment of the present invention.
FIG. 7 is a view showing the relationship between the crushing strength of the
granulated material of an iron ore raw material according to the embodiment of the
present invention and the added amount of Ca(OH)2.
Description of Embodiments
[002 11
When iron ore fines are sieved, an iron ore raw material including the iron ore
fines according to an embodiment of the present invention desirably includes 10 mass%
to 50 mass% of fine particles having a particle diameter of 0.25 mm or less. When the
iron ore raw material includes 10 mass% to 50 mass%, the granulating properties become
favorable, and a granulated material having a large particle diameter is easily obtained.
The fiacti-on of the fine particles of 0.25 mm or less in the iron ore fines is more desirably
20 mass% to 45 mass%.
Furthermore, the fraction of ultrafine particles of 10 ym or less in the fine
particles of 0.25 mm or less is desirably 5 mass% or more, and more desirably 20 mass%
to 70 mass%. This is because, when the fraction of the ultrafine particles of 10 pm or
less in the fine particles of 0.25 mm or less is 20 mass% or more, the ultrafine particles
sufficiently function as a binder. On the other hand, when the fraction of the ultrafine
particles of 10 pm or less in the fine particles of 0.25 mm or less is more than 70 mass%,
it becomes difficult to disperse the ultrafine particles.
[0022] . .
When a granulated material of an iron ore raw material including iron ore fines
is manufactured, in a case in which the total amount of the iron ore raw material is set to
100 parts by mass, 0.01 parts by mass to 10 parts by mass of a high molecular surfactant
which has a hydrophobic group and an acidic fbnctional group and has a molecular
weight of 10000 to 30000, a total of 0.5 parts by mass or more of one or more of CaO
and Ca(OH)2 in which the total is converted in to mass of Ca(OH)2, and 3 parts by mass
to 25 parts by mass of water are added to the iron ore raw material. The hydrophobic
9
-
group refers to a non-ionic functional group having a low affinity to water. The acidic
functional group refers to a group which is dissociated in water so as to become a
a
negative ion. In a high molecular compound of the related art h a d g only a carboxyl
group which do not include a hydrophobic group, the effect of dispersing ultrafine
particles in the presence of CaO and Ca(OH)2 was small. Therefore, the compound was
insuflicient in terms of the granulating properties with respect to the above iron ore raw
material, had a low strength, and was liaile to break. Meanwhile, the amount of CaO is
converted into the amount of c~(oH)b~y using a formula of "converted parts by mass of
Ca(OH)2"-= "parts by mass of CaO x 74/56 with reference to the formula weight of
CaO (56) and the formula weight of Ca(OH)2 (74).
[0023]
(High molecular surfactant)
The inventors found that, when 0.01 parts by mass to 10 parts by mass of a high
molecular surfactant which has a hydrophobic group and qn acidic functional group and
has a molecular weight of 10000 to 30000 is added as a granulating agent to 100 parts by
mass of iron ore fines, a granulated material having favorable granulating properties can
be obtained.
In a case in which an iron ore raw material including iron ore is granulated,
particles of 0.5 mrn or less are attached to nuclear particles having a diameter of 1 mm to
3 mm so as to produce pseudo particles. At this time, the ultrafine particles having a
diameter of 10 prn or less function as a binder, but the ultrafine particles attach to the
nuclear particles.
The inventors found that, when a high molecular surfactant which has a
hydrophobic group and an acidic functional group is added, the effect of actively
dispersing the ultrafine particles from the nuclear particles (hereinafter referred to as the
10 -
.. . * -- "dispersion effect of ultrafine particles") even in the presence of CaO or Ca(OH)2 which
has been reported to reduce a dispersion effect can be obtained.
9
[0024] s
A granulating agent only including an acidic functional group such as a carboxyl
5 group, such as sodium polyacrylate or the like which has been thus far used for
granulation of a raw material, has a capability of dispersing the ultrafine particles of
a-FeOOH or a-Fe203. However, the ulkafine particles in the raw material include clay
such as kaolin as well as a-FeOOH or a-Fe203, and also include coke powder in some
cases. he granulating agent only including an acidic functional group was deficient in
10 dispersibility with respect to clay or coke powder. In the present invention, a high
molecular surfactant obtained by introducing a hydrophobic group in addition to an
acidic functional group into the molecular structure is used as the granulating agent. It
is assumed that the presence of a hydrophobic group makes the high molecular surfactant
be easily adsorbed to not only a-FeOOH or a-Fe203 but also clay or coke powder, and
15 enhances the dispersion effect of ultrafine particles.
[0025]
Furthermore, the high molecular surfactant according to the embodiment of the
present invention has a function of dispersing the particles of CaO or Ca(0H)l. This is - -
assumed to be because the hydrophobic group in the high molecular surfactant becomes
20 liable to be adsorbed preferentially to the particle surfaces of the particles of CaO or
Ca(OH)2. Ca(OH)2 which is generated by a reaction of moisture and CaO uniformly
mixed with ultrafine particles or which is originally added functions as a binder, and
binds ultrafine powder or nuclear particles. Compared to the binding effect of ultrafine
particles alone, it is possible to exhibit a significantly stronger binding effect. When the
25 high molecular surfactant according to the embodiment of the present invention is used,
it is possible to uniformly disperse Ca(OH)2 in ultrafine powder or nuclear particles.
Therefore, it is possible to effectively induce the binding effect using a small amount of
4
CaO or Ca(OH)2. The reasons why 0.01 parts by mass to 10 parts by mass of the high
molecular surfactant which has a hydrophobic group and an acidic functional group and
has a molecular weight of 10000 to 30000 is added to 100 parts by mass of iron ore fines
during granulation are as follows.
In a case in which the content of the high molecular surfactant is less than 0.01
parts by mass, the ultrafine particles are not sufficiently dispersed, the granulating
properties do not improve, and a granulated material having favorable granulating
properties cannot be obtained. Therefore, the lower limit value is set to 0.01 parts by -
mass. In a case in which the content of the high molecular surfactant is more than 10
parts by mass, the raw material turns into slurry such that a granulated material cannot be
obtained, or the costs increases. Therefore, the upper limit value is set to 10.0 parts by
mass.
When the molecular weight of the high molecular surfactant having a
hydrophobic group and an acidic functional group exceeds 30000, the high niolecular
surfactant becomes difficult to dissolve in water. Therefore, the upper limit of the . .
molecular weight is set to 30000.
When the molecular weight of the high molecular surfactant having a
hydrophobic group and an acidic functional group is 10000 or less, the surfactant does
not function sufficiently. This is assumed to be because the size of the hydrophobic
portion constituted by the hydrophobic group becomes insufficient.
In a case in which an alkyl group, an alkyl ester group, or an aryl group is used
as the hydrophobic group, and a salt represented by a carboxyl group, a sulfonic acid
12 -
group, a phosphoric acid group, a sulfate group, -COOMY -SO3M, -HMP04, -M2P04, or
-OS03M is used as the acidic functional group, it is possible to obtain a granulated
k
material having extremely excellent granulating properties. Meangnile, M represents
an alkali metal, an alkaline earth metal, or N&.
(Burnt lime, lime hydrate)
Generally, it has been considered that, when burnt lime and lime hydrate are
incorporated into a granulating agent having a function of breaking up and dispersing an
aggregate;-the dispersion effect is degraded. However, the inventors found that, when a
total of 0.5 parts by mass or more of burnt lime (CaO) andlor lime hydrate (Ca(OH)2) in
which the total is converted in to mass of Ca(OH)2 is used together with 0.01 parts by -
mass to 10 parts by mass of the above high molecular surfactant with respect to 100 parts
by mass of iron ore. fines, a granulated material having favorable granulating properties
and a high crushing strength as shown in the example of FIG. 7 can be obtained.
In the embodiment of the present invention, in a case in which CaO is added,
CaO reacts with moisture in the granulated material so as to turn into Ca(OH)2. This is
because the ultrafine particles having a diameter of 10 pm or less and Ca(OH)2 which are
uniformly dispersed due to the high molecular surfactant function as a binder and
complement each other so as to strengthen the bond between the nuclear particles,
thereby increasing the crushing strength of the granulated material.
When a total of the added amount of the burnt lime andlor lime hydrate is less
than 0.5 parts by mass in which the total is converted in to mass of Ca(OH)2, the crushing
strength of pseudo particles does not improve sufficiently. Therefore, the lower limit of
the total content of the burnt lime andlor lime hydrate converted into amount of Ca(0H)z
a was set to 0.5 parts by mass. When the total content of the burnt lime and/or lime
hydrate converted into amount of ca(0H)~ex ceeds 4.0 parts by mass, the effect of the
b a
granulated material improving the crushing strength is saturated, andbe costs run up.
Therefore, the upper limit of the total content of the burnt lime and/or lime hydrate
5 converted into amount of Ca(OH)2 is preferably set to 4.0 parts by mass.
(Added amount of water)
In a case in which less than 3 parts. by mass of water is added to 100 parts by
mass of iron ore fines during granulation, a granulated material having favorable
10 granulating properties cannot be obtained. Therefore, the lower limit of the added
amount of water is set to 3 parts by mass. This is considered to be because the effect of
the high molecular surfactant dispersing the ultrafine particles cannot be sufficiently
obtained.
In a case in which the added amount of water exceeds 25 parts by mass, the
15 entire raw material turns into slurry, and it becomes impossible to obtain a granulated
material such that the raw material drastically attaches to the wall surfaces of the vessel
of a granulating machine, and the productivity is degraded. Therefore, the upper limit
of the added amount of water is set to 25 parts by mass. -
[003 01
(Blending of pellet feed)
In the embodiment, even when some of iron ore fines including a large amount
of fine powder is substituted by pellet feed, it is possible to obtain a favorable granulated
material. The pellet feed refers to cheap iron ore having an average particle diameter of
approximately several tens of pm to 100 pm far which the content of iron is increased to
25 approximately 65 mass% or more by crushing and water-washing iron ore including a
d .- small amount of iron, and the content of a gangue component, for example, A1203 is
decreased to approximately 1.5 mass% or less. Since the pellet feed has flat ore
\ ti
surfaces, and rarely includes ultrafine powder of 10 pm or less, the fillet feed is not
easily granulated. In the embodiment, pellet feed including 90 mass% or more of fine
5 particles of 0.25 mrn or less and 5 mass% or less of ultrafine powder of 10 pm or less
was used as the pellet feed. The inventors found that, even with an iron ore raw
material in which the pellet feed is blended with iron ore fines, it is possible to obtain a
granulated material which has a high crushing strength of pseudo particles, maintains a
high strength even in the presence of moisture, and does not turn into powder or break by
10 adding 0.01 parts by mass to 10 parts by mass of the high molecular surfactant in
addition to the burnt lime (CaO) andlor lime hydrate (Ca(OH)2) to 100 parts by mass of .
the iron ore raw material. The amount of the pellet feed blended into the iron ore raw
material is desirably 2 to less than 90 in terms of x in a c.ase in which the mass ratio
between the iron ore fines and the pellet feed is set to (100.-x):x. When x is 90 or more,
15 there are cases in which the strength of the granulated material decreases, and the amount
of a granulated material of 0.25 mm or less increases. On the other hand, when x is less
than 2, the effect of reducing the gangue component such as A1203 becomes small due to
use of the pellet feed. . .
[003 11
(Composition of the granulated material)
The granulated material of an iron ore raw material including iron ore fines or an
iron ore raw material including iron ore fines and the pellet feed according to the
embodiment of the present invention is manufactured using the method of manufacturing
a granulated material according to the embodiment of the present invention. The
composition of the granulated material of iron ore is 0.0096 (=0.01/104.01 x 100) mass%
to 9.05 (=10/110.5x100) mass% of the high molecular surfactant which has a
4
hydrophobic group and an acidic functional group and has a molecular@veight of 10000
to 30000 and 0.45 (0.5/110.5x100) mass% or more of the lime hydrate in addition to iron
ore fines or a mixture of iron ore fmes and the pellet feed, which are a major component.
Moisture is not included in the composition. The compositional proportions of
elements included in the granulated matetial can be identified through fluorescent X-ray
analysis and inductively coupled plasma (ICP) atomic emission spectrometry. Crystal
phases in the granulated materials can be identified using powder X-ray diffraction.
[Examples]
Iron ore fmes I and 11 were used as raw materials for manufacturing granulated
materials of iron ore raw material. Table 1 shows the components included in the iron
ore fmes I and 11 and the particle diameter distribution.
table 1
Fraction
of
ultrafine
particles
of
10 pm or
less
in
particles
of
0.25 mm
or less
(mass%)
24%
21%
Iron ore
fmes
I
n
Particle size distribution (mass%)
>5 mm
0%
8%
0.25-0.5
mm
18%
21%
<0.25
mm
25%
11%
2-5 m
15%
18%
1-2 IIXII
22%
17%
0.5-1
m
20%
25%
In a case in which the iron ore fmes I and 11 are sieved at larger than 5 mm, 2
mm to 5 mm, 1 mm to 2 rnm, 0.5 mm to 0.25 rnm, and smaller than 0.25 mm, the
5 fiaction of fine particles of 10 pm or less included in fine particles of 0.25 mm or less is
20 mass% or more. The amount of the ultrafine particles of 10 pm or less was
measured using a laser difhction particle size distribution analyzer on a specimen of
0.25 mm or less.
Table 2 shows the names of granulating agents A to F. In addition, the
10 molecular structures of the granulating agents A to F are shown in FIGS. 1 to 6,
respectively. The granulating agent B is a polymer molecule having a complicated
three-dimensional structure based on the structure of FIG 2. Regarding the molecular '
weight, the weight average molecular weight (h4w) was measured using chromatography
(GPC: gel permeation chromatography). A to D are the high molecular surfactants
15 having a hydrophobic group and an acidic functional group according to the embodiment
of the present invention, and the molecular weight is 10000 to 30000. E and F are high
molecular surfactants not including a hydrophobic group such as sodium polyacrylate.
[0035]
Table 2
Granulating agent
A I Copolymer of
Molecular
weight
(Mw)
15,200 -
Hydrophobic group
-CH3 (methyl group),
Acidic functional group
-COONJ&
Tables 3 and 4 show the results of granulation of the iron ore fines I and I1 using
D
E
F
the granulating agents A to F. The results of Examples are shown in Table 3, and the
5 results of Comparative examples are shown in Table 4. Values outside the preferable
three-dimensional
polymer molecule (FIG.
2)
Copolymer of sodium
polysulfonate and
ethyl polyacrylate (FIG.
3
Copolymer of sodium
polycarbonate,
polystyrene (FIG. 4)
--
Sodium polyacrylate
(FIG. 5)
Copolymer of sodium
polymaleate and
polyethylene (FIG. 6)
ranges of the embodiment are underlined. -.
Tables 5 and 6 show the results of granulation of iron ore raw materials which
were obtained by mixing Rio Doce PF or MBR-PF as the pellet feed with the iron ore
fines I and 11 using the granulating agents A to F. The results of Examples are shown in
16,500
25,500
8,600
24,000
10 Table 5, and the results of Comparative examples are shown in Table 6. Values outside
the preferable ranges of the embodiment are underlined.
OCH3 and I- the like (after dissociation of
~ a ' ,
@ sulfonic acid group)
-COOC2H5 (ethyl ester
group)
-S03Na
(after dissociation of
Na',
sulfonic acid group)
43
tpnenyl group) I -COONa
-COOC2&OCH2CH(CH3)2
None
None
(after dissociation of
Na+,
carboxyl group)
-COONa
(after dissociation of
~ a ' ,
carboxyl group)
-COONa -
(after dissociation of
N$,
carboxyl group)

table 4
(*4)-GOOD: Pass; POOR: Fail
a, _a -
table 5
(*4)-GOODP:as s; POOR:F ail
2d *
table 6
(*4)-GOOD: Pass; POOR: Fail
The granulated materials were evaluated to be a pass (GOOD) in a case in which
i
both the granulating properties and the crushing strength of the grandated materials
passed the criteria, and evaluated to be a fail (POOR) otherwise.
In the examples, the compositional proportions of elements included in the
granulated materials of the iron ore fines were identified through fluorescent X-ray
analysis. In addition, the crystal phases in the granulated materials were identified
through powder X-ray di~actioh. Table 3 shows the contents of the granulating agents
and'the contents of Ca(OH)2 in the granulated materials.
Regarding the granulating properties, the granulated materials having a fraction
of pseudo particles of less than 0.25 mm of 3 mass% or less were evaluated to be a pass, -
and the granulated materials having a fraction of more than 3 mass% were evaluated to
be a fail.
Regarding the crushing strength of the granulated materials, ten dried granulated
materials having a particle diameter of 4 mm to 6 mm were selected, a load was added
using a compression tester, and the loads F (kgf) at which the granulated materials were
crushed (hereinafter referred to as the "crushing strength) were measured. The
granulated materials having an average value of values obtained by dividing the loads F
by the cross-section areas S (cm2) of 10 kgf/cm2 or more were evaluated to be a pass, and
the granulated materials having an average value of less than 10 kgf7cm2 were evaluated
to be a fail.
Here, as the cross-section area, the cross-section area S (cm2) of a surface cut at
the surface including the center of the assumed sphere of the granulated material was
used. That is, when the diameter of the sphere is d (cm), since S=xx(d/2)x(d/2), the
crushing strength P is computed using P = F / s = ~ F / ~ ~As~ t.h e diameter d of the
?3 -
granulated material, for example, the average value d, of the maximum value dm, and
the minimum value d- of the measured diameters of the granulated material was used.
4
At a crushing strength of 10 kgf/cm2, since the area of the crbss section cut at a
plane including the center of a sphere having a diameter of 5 mm is 0.2 cm2 (~0.25
cmx0.25 cmxn), a load F of approximately 10 kgI7cm2x0.2 cm2=2 kgf is applied to the
granulated material having a diameter of 5 mm, and the granulated material breaks.
[0042]
Hereinafter, the respective examples will be described specifically.
(11 a case in which iron ore fines were granulated)
In a case in which the iron ores I and I1 described in Table 1 were set to 100
parts by mass, granulation treatments were carried out by dissolving the granulating
agents A to F and water in the mixing ratios shown in Tables 3 and 4, and adding the
mixture to 100 parts by mass of the iron ores I and I1 prepared together with CaO or
Ca(OH)2. During granulation, a pan-type mixer was rotated for five minutes at a
rotation rate of 20 min-I. Granulation results were shown in Table 3 for Examples 1 to
44 and in Table 4 for Comparative examples 1 to 25. Comparative examples 1 to 6 do
not include CaO or Ca(OH)2.
Examples 1 to 44 pass the criteria with fractions of pseudo particles of less than
0.25 mrn of 3 mass% or less and with results of 10 kgf/cm2 or more in the crushing
strength tests. On the other hand, as in Comparative examples 1 to 25, in a case in
which CaO or Ca(OH)2 was not included, a case in which a granulating agent outside the
preferable range was used, or a case in which the added amount of the granulating agent
was outside the preferable range, the granulated material failed to pass the criteria with
fractions of pseudo particles of less than 0.25 mm of more than 3 mass%, and with
results of less than 10 kgf/cm2 in the crushing strength tests. The granulated material of
2Q
-
Examples 1 to 44 did not break even when immersed in water, and were extremely
excellent in terms of water resistance.
(In a case in which the pellet feed was blended with the iron ore fines)
In a case in which Rio Doce PF or MBR-PF was mixed as the pellet feed with
the iron ore fines I or I1 described in Table 1, and a total amount of 100 parts by mass of
the mixture was prepared, granulation trektments were carried out by adding CaO andlor
Ca(OH)2, furthermore, dissolving 0.01 parts by mass to 10 parts by mass of the
granulating agents A to F in 3 parts by mass to 25 parts by mass of water, and adding the
10 mixture to 100 parts by mass of the prepared iron ore raw material. During granulation,
a pan-type mixer was rotated for five minutes at a rotation rate of 20 min-'.
Granulation results were shown in Table 5 for Examples 45 to 73 and in Table 6
for Comparative examples 26 to 35.
15 Examples 45 to 73 pass the criteria with fi-actions of pseudo particles of less than
0.25 mm of 3 mass% or less and with results of 10 kgi7cm2 or more in the crushing
strength tests. On the other hand, as in Comparative examples 26 to 35, in a case in
which a dispersant outside the preferable range was used, or a case in which granulation -
was carried out only using a pellet feed not including iron ore fines, the granulated
20 material failed to pass the criteria with fractions of pseudo particles of less than 0.25 mm
of more than 3 mass%, and with results of less than 10 kgf/cm2 in the crushing strength
tests. The granulated materials of Examples 45 to 73 did not break even when
immersed in water, and were extremely excellent in terms of water resistance.
In order to clarify the relationship between the added amount of Ca(OH);? and
25 the granulating properties and strength in the vicinity of the lower limit value of the
25 -
4 - 4 . - added amount of Ca(OH)2 which was 0.5 parts by mass, experiments were carried out.
Rio Doce PF (30 parts by mass) was mixed as the pellet feed with 70 parts by mass of
b i
iron ore fines I described in Table 1, and a total amount of 100 parts By mass of an iron
ore taw material was prepared. In addition, granulation treatments were carried out by
5 dissolving 0 parts by mass to 0.65 parts by mass of Ca(0H)z and 0.3 parts by mass of the
granulating agent B in 10.0 parts by mass of water, and adding the mixture to 100 parts
by mass of the iron ore raw material preph-ed above. During granulation, a pan-type
mixer was rotated for five minutes at a rotation rate of 20 min-'. Granulation results are
shown in Table 7 for Examples 74 and 75 and for Comparative examples 36 to 39. The
10 relationship between the crushing strength of the granulated material and the added
amount of Ca(OH);! is shown in FIG. 7. At 0.5 parts by mass, or more, which is the
lower limit of the added amount of Ca(OH)2 of the present invention the crushing
strength significantly improves, and exceeds a strength of 10 kgf7cm2 or more.
table 7
Comparative
example 36
Comparative
example 37
Comparative
example 38
Comparative
example 39
Example 74
Example 75
, A d \ --AIron
ore raw material
Iron ore
fine
I
I
I
I
I
- . I- -
Granulating agent Parts by
mass of
Ca(OH)2
0.00
0.15
0.30
0.40
0.50
0.65
Parts by
mass
70.0
70.0
70.0
70.0
70.0
--7 0-.-0 -.
Granulating
agent
B
B
B
B
B
B
Parts by
mass
0.30
0.30
0.30
0.30
0.30
0.30
Parts by
mass of
water ,
10.0
10.0
10.0
10.0
10.0
10.0
Pellet feed
Rio Doce PF
Rio Doce PF
Rio DocePF
RioDocePF
Rio Doce PF
R-io Doce PF
Parts by
mass
30.0
30.0
30.0
30.0
30.0
30.0
Fraction of less
than 0.25 mm
8%
6%
6%
5%
2%
1%
Crushing strength
[kgf/cm2]
3
--
4
5
6
12
15
Evaluation
(* 1)
POOR
--
POOR
POOR
POOR
GOOD
GOOD
[0046]
(Productivity of a sinter)
4
In the embodiment, it is possible to significantly improve th8 sintering
productivity by substituting some or all of a granulated material obtained by granulating
5 burnt lime as a binder, which has been thus far carried out, with the granulated material
of an iron ore raw material according to the embodiment.
The productivity of a sinter can be measured using the finished product yield of
a sinter and the sintering duration. For example, the finished product yield can be
evaluated-by measuring the fraction of particles having a particle size of a particle
10 diameter of 5 mm or more when a sintered sinter (sinter cake) has been dropped five
times from a height of 2 m onto an iron plate in a sintering pan test. In addition, the
production rate can be computed using the following formula.
Production rate (t/day/m2) = the total mass of particles having a particle size of a
particle diameter of 5 mm or more after finished product yield evaluation (t) 1 sintering
15 duration (day) / the surface area of a sintering machine (pan) (m2)
[0047]
A specific example will be shown. Burnt lime (1.0 part by mass), coke, and
water were added to 100 parts by mass of any of the iron ore fines I and I1 described in . .
Table 1 or a raw material obtained by mixing the iron ore fines I and I1 with the pellet
20 feed, and a granulated material granulated for 5 minutes in a drum mixer at a rotation rate
of 20 min" (hereinafter considered as a granulated material of the related art) was
manufactured. The granulated material according to the embodiment was added to the
granulated material of the related art, and the mixture was mixed for one minute in a
drum mixer at a rotation rate of 20 min-'. In order to measure the amount of moisture,
25 500 g of the mixed raw material was dried for 2 hours at 150°C, and the weight was
) measured before and after drying. The coke was blended so that the amount of the coke
became 4.5 parts by mass with respect to the entire raw material. Sintering was carried
b i
out in a 70 kg-scale pan test using the above raw material, and a sinte!" was obtained.
The.test conditions were a sintering pan having a diameter of 300 mm, a height of 650
5 mm, and a layer thickness of 500 mm, and a negative suction pressure of 9.8 kPa
(constant). The production rate of the obtained sinter was measured. The results are
shown in Table 8.
table 8
Raw material blending .
Granulated material Parts by
~mnuiatedm aterial of the invention Parts by
of the related art (*I) mass mass
Comparative example 40
Example 76
Amount of
moisture
e/.)
Example 77
Comparative example 41
Iron ore fine I
Iron ore fine I
Example 78
Example 79
Sintering
production rate
(t/dayld)
Iron ore fine I
. Iron ore fine II
Example 80
Example 8 1
Comparative example 42
Evaluatio~
(*2)
100
70
Iron ore fine 11
Iron ore fine n
Example 82
Example 83
70
100
Iron ore fine I1
None
lron ore fine I (90%)+Riodose PF (10%)
Example 84
Comparative example 43
None I
Table 3, granulated material of Example 2
80
50
Jron ore fine 1 (95%)+Riodose PF (5%)
Iron ore fine I
Example 85
Example 86
Table 3, granulated material of Example 24
None
50
0
100
Iron ore fine I
Iron ore fine I1 (90%)+MBR-PF (10%)
Example 87
Comparative example 44
(*2) -GOOD: PASS; POOR: FAlL
0
30
Table 3, granulated material of Example 18
Table 3, granulated material of Example 18
80
50
Iron ore fine I1 (~~%)+MBR-P(5F% )
Iron ore fine I1
Comparative example 45
Comparative example 46
30
0
Table 3, granulated material of Example 40
Table 3, granulated material of Example 1
None
50
100
None
Iron ore fine 1
7.5
7.4
20
50
Table 5, granulated material of Example 45
Table 5, granulated material of Example 45
80
95
(*I) Granulated material granulated using burnt lime as a binder
Iron ore. fine 1
Iron ore fine I1
7.4
7.2
50
100
0
Table 5, granulated material of Example 50
None
0
70
24.5
28.4
7.3
7.3
20
50
Table 5, granulated material of Example 55
Table 5, granulated material of Example 57
95
95
POOR
GOOD
29.5
25.1
7.2
3.0
7.4
50
0
-- --- --
Table 5, granulated material of Example 49
Table 4, granulated material of Comparative example 8
GOOD
POOR
.
27.6
28.4
7.4
7.4
20
5
-- -
Table 6, granulated material of Comparative example 26
Table 6, granulated material of Comparative example 28
GOOD
GOOD
28.0
30.8
23.3
7.3
7.3
100
30
GOOD
GOOD
POOR
-
27.2
32.2
7.4
7.3
5
5
GOOD
GOOD
-
30.7
22.4
- --
2.6
7.4
--
GOOD
POOR
27.0
32.8
7.2
7.2
GOOD
GOOD
27.5
24.2 '
GOOD
POOR
25.1
24.8
POOR
POOR
30
[0049]
Examples 76 to 87 are the results of the granulated materials according to the
i
embodiment of the present invention or the sintering production rate! in a case in which
some or all of the granulated material of the related art was substituted with the
granulated material according to the embodiment of the present invention. Comparative
examples 40 to 46 are the results in a case in which only the granulated material of the
related art which did not include the gran;lated material according to the embodiment of
the present invention was used, or a granulated material outside the preferable range of
the embodiment was used. A sinter productivity of less than 26% was evaluated to be a
fail, and a sinter productivity of 26% or more was evaluated to be a pass. In Examples
76 to 87 for which the granulated material according to the embodiment of the present .
invention was used, all sinters achieve a high sintering production rate.
Industrial Applicability
[0050]
According to the method of manufacturing a granulated material of an iron ore
raw material according to the embodiment of the present invention, it is possible to
obtain a granulated material having a small fraction of particles having a small particle
diameter in particles that configure the granulated material, for example, a granulated
material having a fraction of pseudo particles having a particle diameter of less than 0.25
mm of 3 mass% or less. As a result, for example, it is possible to obtain a granulated
material having a strength of 10 kgf7cm2 or more. In addition, it is possible to
sufficiently improve the sintering productivity simply by substituting some of a
granulated material obtained by granulating burnt lime as a binder, which has been thus
25 far carried out, with the granulated material of the present invention.

3 (b
CLAIMS
4
1. A method of manufacturing a granulated material of an f on ore raw
material, the method comprising a process of adding
0.01 parts by mass to 10 parts by mass of a high molecular surfactant which has
a hydrophobic group and an acidic functional group and has a molecular weight of 10000
a total of 0.5 parts by mass or more of one or two of CaO and Ca(OH)2 in which
the total is converted into mass of Ca(OH)*, and
10 3 parts by mass to 25 parts by mass of water,
to a total amount of 100 parts by mass of the iron ore raw material including iron -
ore fines.
2. The method of manufacturing the granulated material of the iron ore raw
15 material according to Claim 1,
wherein the iron ore raw material includes the iron ore fines and a pellet feed.
3. The method of manufacturing the granulated.materia1 of the iron ore raw
material according to Claim 2,
2 0 wherein, in a case in which a mass ratio between the iron ore fines and the pellet
feed is defined as (100-x):x, x is from 2 to less than 90.
4. The method of manufacturing the granulated material of the iron ore raw
material according to any one of Claims 1 to 3, -
wherein the hydrophobic group is at least one kind of an alkyl group, an alkyl
a d r .- ester group, and an aryl group, and
in a case in which M is defined as an alkali metal, an alkaline earth metal, or
\ 4
NH4, the acidic functional group is at least one kind of salt represent8d by a carboxyl
group, a sulfonic acid group, a phosphoric acid group, a sulfate group, -COOM, -S03M,
5 -HMPOd, -MzPOJ, or -OSO3M.
5. The method of manufacturing the granulated material of the iron ore raw
material according to Claim 4,
wherein the iron ore fines include fine particles of 0.25 mm or less, and a
10 fraction of ultrafine particles of 10 pm or less in the fine particles is 20 mass% to 70
6. The method of manufacturing the granulated material of the iron ore raw
material according to any one of Claims 1 to 3,
wherein the iron ore fines include fine particles of 0.25 mm or less, and
the fraction of ultrafine particles of 10 pm or less in the fine particles is 20
7. A granulated material of an iron ore raw material, comprising:
iron ore fines;
0.0096 mass% to 9.05 mass% of a high molecular surfactant which has a
hydrophobic group and an acidic functional group and has a molecular weight of 10000
to 30000, and
0.45 mass% or more of lime hydrate.
33 - -
# .:. 8. A granulated material of an iron ore raw material, comprising:
d
d - .
iron ore fines and pellet feed;
, 4.
b 0.0096 mass% to 9.05 mass% of a high molecular sulfactanf)vhich has a
hydrophobic group and an acidic functional group and has a molecular weight of 10000
5 to 30000, and
0.45 mass% or more of lime hydrate. . .
9. The granulated mat'erial of the iron ore raw material according to Claim 8,
wherein, in a case in which a mass ratio between the iron ore fines and the pellet --
10 feed is defined as (100-x):x, x is from 2 to less than 90.
10. The granulated material of an iron ore raw material according to any one
of Claims 7 to 9,
wherein the hydrophobic group is at least one of an allcyl group, an alkyl ester.
15 group, and an aryl group; and
in a case in which M is defined as an alkali metal, an alkaline earth metal, or
NH4, the acidic functional group is at least one kind of salt represented by a carboxyl
group, a sulfonic acid group, a phosphoric acid group, a sulfate group, -COOM, -S03M,
Dated this 1 1.04.20 13 .
S ~ $ I G N H
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANT[S]-