JP6376143B2 - Processing method of sintering raw material - Google Patents

Description

  The present invention relates to a method for treating a sintered material that suppresses aggregation and uneven distribution of the sintered materials.

In the Dwytroid-type sintering machine that produces sintered ore, a sintering raw material composed of iron sources such as powdered iron ore, iron sand, and mill scale and auxiliary materials such as limestone and serpentine is kneaded and granulated. To the sinter pallet through the roll feeder.
A sintering raw material charging layer having a predetermined thickness is formed on the sintering machine pallet. The lower surface of the sintering machine pallet is a grate called a great bar. The surface of the sintering material charging layer is ignited by an ignition burner, and the air above the sintering material charging layer is lowered by an exhaust fan. Sintering is carried out by advancing the pallet of the sintering machine to the exit side of the Dwytroid sintering machine.
In the operation of the dwy-toroid sintering machine, the air permeability of the sintering raw material charging layer is ensured and the gas flow is made uniform, so that uneven baking is eliminated and the yield of sintered products is improved.
For this reason, conventionally, various methods have been proposed as pretreatment of the sintering raw material.

  For example, in Patent Document 1, an iron-containing dust collection dust is preliminarily subjected to carbonation treatment, and an alkaline earth metal oxide and / or an alkaline earth metal hydroxide contained in the iron-containing dust collection dust is disclosed. For ironmaking, which is stabilized and precipitated as alkaline earth metal carbonate, and then kneaded and granulated by adding water to iron-containing dust collection dust or other iron-containing raw materials with this iron-containing dust collection dust A method of granulating iron-containing dust collection dust has been proposed. In Patent Document 1, in addition to the carbonation treatment, when granulating, the dispersibility of ultrafine particles having a particle diameter of 10 μm or less in water is further improved, the granulating property is improved, and crushing after granulation is performed. In order to improve the strength, it is disclosed that it is preferable to add a dispersant having an action of enhancing the dispersibility of particles in water to the iron-containing dust collecting dusts when granulating. Dispersant is preferably sodium silicate, sodium polyacrylate, sodium tannate, sodium pyrophosphate, sodium hexametaphosphate, sodium polyphosphate, and more preferably sodium silicate, sodium polyacrylate, sodium tannate Has been.

Further, Patent Document 2 discloses a flocculant, a hydrophobic agent, and a repellent agent on a surface layer of a granulated product obtained by wet granulating a blended raw material containing powdered iron ore, a carbonaceous material, and a lime-containing auxiliary raw material using a piper. A method for treating a granulated product for sintering is disclosed in which a coated granulated product to which a strength reduction inhibitor composed of any one or more of liquid agents is attached is supplied to a sintering machine.
Patent Document 3 discloses the total amount of fine particles having a particle diameter of 10 μm or less dispersed in a granulated product until the sintering material is kneaded when the sintering material is kneaded with a kneader. The fine particles are added so that the mass ratio with respect to the dry sintered raw material is 11% or more, and the dispersing agent for dispersing the fine particles in the sintered raw material is added, and the tip speed of the stirring blade of the kneader is 3 m. A pretreatment method for a sintering raw material that is kneaded for at least 70 seconds / second is disclosed.

  Patent Document 4 discloses a binder addition method and an addition device that can uniformly add a binder to an iron ore raw material and can control the concentration and score of the binder with high accuracy and speed in granulation of the iron ore raw material. Is disclosed. In this binder addition method, a mixing nozzle that mixes the binder and water separately supplied from the binder supply pipe and the water supply pipe is arranged near the raw material charging portion described in the root column, and the binder and water are mixed from the mixing nozzle. The aqueous binder solution is sprayed on the iron ore raw material charged in the raw material charging portion of the kneader.

JP 2008-38181 A International Publication No. 2010/098329 JP 2012-162696 A International Publication No. 2010/114152

By the way, the iron ore used as an iron source among the sintering raw materials usually has a brand A containing a large amount of alumina Al ₂ O ₃ , a brand B which is a powdered iron ore, and has high adhesion, and has an alumina Al ₂ content. In order to form a sintered raw material charged into the moving pallet using the brand C having a low O ₃ content and the auxiliary material, the brand A and the brand C are used to make the alumina Al ₂ O ₃ uniform. Are stacked in multiple layers on a yard with a rectangular bottom so that the weight ratio is, for example, 1: 1, and the remaining brand B is also stacked in multiple layers in the same yard and is reclaimed in a direction perpendicular to the longitudinal direction of the rectangle. A blending powder (B powder) that is cut out and uniformly mixed is formed, the blending powder and the auxiliary material are charged into a mixer, added with water, kneaded, and then granulated by a granulator.

And the amount of granulated undersintering is charged into a moving pallet using a roll feeder, for example, to form a sintered raw material layer of a predetermined thickness, and an ignition burner ignites the surface layer portion of the sintered raw material layer, Firing is performed by advancing the moving pallet to the exit side while sucking the air above the sintering material layer downward with an exhaust fan.
At this time, it is desirable that each brand after kneading is uniform in both particle size composition and chemical composition, but in fact, brand C with a low content of alumina Al ₂ O ₃ has high adhesion, It often becomes dumpling. Therefore, without stocks C content is less of alumina Al ₂ O ₃ is mixed with the stock A high content of alumina Al ₂ O _3, occurs the inhibition of physical gas flow by bunching stock C, The other portions are relatively in a high alumina Al ₂ O ₃ state, which lowers the fluidity of the melt, impedes aeration, and lowers the strength due to insufficient firing.

However, in the conventional examples described in Patent Documents 1 to 4, when the blending powder and the auxiliary material are charged into a mixer and kneaded by adding water, or after being kneaded by the mixer, the sintered raw material In order to increase the strength of the granulated product by adding a dispersing agent or the like when granulating the material with a granulator, the brand C having a low content of alumina Al ₂ O ₃ becomes a dumpling before kneading. Cannot be prevented.

  Therefore, the present invention has been made paying attention to the problems of the conventional example described above, and suppresses the adhesion of low alumina-containing ores having a low alumina content, so that a high alumina-containing ore and a low alumina-containing ore are uniformly distributed. It aims at providing the processing method of the sintering raw material which can be mixed and can suppress the uneven distribution of an alumina.

  In order to achieve the above object, one aspect of the method for treating a sintered raw material according to the present invention is a high alumina content ore having a high alumina content, and a low alumina content having a lower alumina content than the high alumina content ore. Adhesive inhibitor for ores containing low alumina when blending powder blended with at least mixed ore and auxiliary material and granulated and then sintered raw material is charged into moving pallet and fired Is added to obtain a blending powder in which at least a low alumina content ore and a high alumina content ore are uniformly dispersed.

  According to one aspect of the present invention, it is possible to obtain a blending powder in which aggregation of the low alumina-containing ore is suppressed by the adhesion inhibitor, and at least the low alumina-containing ore and the high alumina-containing ore are uniformly mixed. When blending powder and auxiliary material are kneaded and granulated to form a sintered raw material, when this sintered raw material is charged onto a moving pallet, the ore containing low alumina is unevenly distributed. Inhibition of the physical gas flow due to the above, and the fluidity of the melt due to the uneven distribution of high alumina are reduced, and the strength reduction can be suppressed due to the inhibition of ventilation and insufficient firing.

It is a figure which shows the flow of the ore at the time of enforcing the processing method of the sintering raw material of this invention, and the manufacturing flow of a sintered ore. It is explanatory drawing which shows the aggregation mechanism of a polymer flocculent model, Comprising: (a) is a figure which shows an aggregation state, (b) is a figure which shows a dispersion state. It is explanatory drawing which shows the mixing state of each brand, Comprising: (a) is explanatory drawing of a prior art example, (b) is explanatory drawing of this embodiment. It is explanatory drawing which shows the ventilation | gas_flowing state in a sintering machine, Comprising: (a) is explanatory drawing of a prior art example, (b) is explanatory drawing of this embodiment. It is a graph which shows the product yield which is an experimental result.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
FIG. 1 shows a sintering facility. Iron ore transported by an ore carrier 11 is placed and transported on a horizontal belt conveyor 13 by an unloader 12 disposed on a quay, and then a stacker boom conveyor. 14 is dropped from the upper end of the stacker boom conveyor 14 onto the ore stock yard 15 and piled up for each brand of iron ore. Here, in order to simplify the explanation, on the ore stock yard 15, a brand A which is a high alumina-containing ore with a high content of alumina Al ₂ O ₃ , a brand B which is a fine ore, and a high adhesion property are provided. In addition, three piles MA, MB, and MC are formed with the brand C of the low alumina-containing ore in which the content of alumina Al ₂ O ₃ is 1.65% or less.

The low alumina containing ore stocks C is when that will be piled, it is piled with the addition of adhesion inhibitor 16 for example at the upper end of the stacker boom conveyor 14. Here, adhesion inhibitor 16, the use of agents as a main component a polymer flocculant as the chemical. Alternatively, if the drug is on a solid, it is dispersed in a solution and used as a drug solution.
As the above polymer flocculant, by electrostatic forces or hydrogen bonds with the polymer powder to occur the adsorption activity intended to cause the powder between crosslinking action, aggregated particles to form a solid particle structures ( Any material can be used as long as it has an effect of forming an aggregate. For example, polyacrylamide-based (copolymerized acrylamide and sodium acrylate), polyvinylamidine-based, and amphoteric polymer-based aggregating agents are preferable because they exhibit not only a coagulation action but also an aggregation action. In addition, it is good also as mixing together and using a well-known inorganic type coagulant | flocculant.

Furthermore, as the polymer flocculant, acrylic acid cationic polymer, acrylamide cationic polymer, methacrylic acid polymer, methacrylic acid amino ester cationic polymer, amidine polymer, anionic W / O emulsion polymer, and the like can be used.
In the present invention, the main component of the polymer flocculant generally refers to a drug containing a polymer flocculant in an amount that is recognized as having an aggregating effect. It is a drug with a content of about% or more. Of course, a polymer flocculant having 100% may be used as it is.

The drug is in a solid state, or. When diluted, the solution includes water and an induction solvent, the solute includes a polymer of C, H, N, and O, and the solvent includes a hydrocarbon solvent (only C, H, and O).
Furthermore, it is preferable that the addition amount of the chemical | medical solution in this invention is contained about 0.01-0.1% with respect to the water content of the low alumina content ore of the brand C.

In the present embodiment, the original aggregating action of the polymer flocculant is not expected, but the dispersing action of the low alumina-containing ore of brand C is expected. Adsorption of adjacent particles by increasing the amount used. The active point is not connected.
That is, when the polymer flocculant exerts its original condensing action, as shown in FIG. 2 (a), a small amount of random coil-shaped polymer flocculant 42 is added to the fine alumina particles 41 of the low alumina content of brand C. When added, a part of the polymer flocculant 42 is adsorbed to a part of the adsorption active sites on the surface of the fine particles 41 by electrostatic bonds and hydrogen bonds, and the remaining part extends to the outside of the fine particles 41. Adsorbing active sites of adjacent particles are bonded and crosslinked to exert an aggregating action.

On the other hand, when a large amount of the polymer flocculant 42 is added, as shown in FIG. 2B, the adsorption active sites on the surface of the fine alumina particles 41 of the low alumina content of brand C are all occupied by the flocculant molecules. As a result, the surface of the particles becomes the same charge, so that the inherent cross-linking action of the flocculant does not work and is in a dispersed state.
However, if the polymer flocculant 42 is too much, the moisture (for example, the water content is 9%) contained in the low alumina-containing ore of the brand C is completely separated. By selecting in the range of 0.01 to 0.1% of the water content of the low alumina content ore of C, the fine particles of the brand A low alumina content ore can be dispersed without separating the moisture.

That is, when the amount of the polymer flocculant 42 added is less than 0.01 of the water content of the grade C low alumina-containing ore, the inherent crosslinking action of the polymer flocculant 42 occurs, The cross-linking action of the fine particles 41 is exerted, and the adjacent fine particles are condensed to promote the formation of a dumpling-like lump.
Moreover, when the addition amount of the polymer flocculant 42 exceeds 0.1% of the water content of the brand C low alumina-containing ore, the dispersion of the fine particles 11 of the brand C low alumina-containing ore proceeds and the water is separated. Therefore, when piled up, moisture accumulates in the lower layer, and the fine particles of the low-alumina-containing ore of the upper grade C are easily scattered, which is not preferable. Furthermore, it influences the granulation to which moisture is added in the subsequent granulation step.

And, using the reclaimer 17 for each of the brands A, B and C from the piles MA, MB and MC formed by stacking the brands A, B and C, the brands A, B and C are dispensed by the blending stacker 18. The blending mountain 19 is formed by alternately stacking in a multilayer state.
Next, blending powder (B powder) in which the brands A to C are uniformly mixed is cut out by a blending reclaimer 20 from a direction orthogonal to the longitudinal direction of the blending mountain 19 and accommodated in the blending powder hopper 21A. Moreover, the return ore having a particle size smaller than the predetermined particle size generated after sintering is accommodated in the return ore hopper 21B. On the other hand, a carbon material composed of powdered coke or anthracite fine powder is accommodated in the carbonaceous hopper 21C, and auxiliary materials including quick lime and limestone are accommodated in the auxiliary material hopper 21D.

The blending powder contained in the blending powder hopper 21A, the return mineral contained in the return hopper 21B, the carbon material contained in the carbon hopper 21C, and the auxiliary material contained in the auxiliary material hopper 21D Quantitatively cut out at a predetermined rate.
The cut out raw material is added with an appropriate amount of water using a drum mixer 22, 23, etc., mixed and granulated to obtain a sintered raw material which is a pseudo particle having an average diameter of 3.0 to 6.0 mm. On the other hand, the lump ore obtained by crushing the sintered cake and adjusting the particle size to a predetermined particle size is cut out from the floor hopper 24 and a floor layer is formed on the great of the sintering machine pallet 31.

  The sintering raw material is charged on the floor layer on the endless moving type sintering machine pallet 31 through a roll feeder 33 and a cutting chute 34 from a surge hopper 32 arranged on the sintering machine pallet 31. Then, a charging layer 35 of a sintering material, also called a sintering bed, is formed. The thickness (height) of the charging layer 35 is usually around 400 to 800 mm. After that, an ignition furnace 36 installed above the charging layer 35 ignites the carbon material in the surface layer of the charging layer 35 and air through a wind box 37 disposed under the pallet 31. Is sucked downward to sequentially burn the carbonaceous material in the charging layer, and the sintered raw material is burned and melted by the combustion heat generated at this time to obtain a sintered cake. The sintered cake thus obtained is then crushed and sized, and recovered as a product sintered ore comprising agglomerates of 5.0 mm or more.

  In this way, the iron ores of various brands A to C are mixed to form a product sintered ore. In this embodiment, when the piles MA to MC for the brands A to C are formed. In addition, when stacking the low alumina-containing ore of brand C, a polymer flocculant is used as an adhesion suppressant in an amount of 0.01 to 0 with respect to the water content (for example, 9 wt%) of the low alumina-containing ore of brand C. .1 wt% is added so as to have a dispersibility that does not separate moisture from the low alumina-containing ore of grade C having high adhesion.

For this reason, it can suppress that a water | moisture content isolate | separates in the pile MC of the low alumina content ore of brand C, and it accumulates in a lower layer, and it can control that it becomes easy to scatter on the upper layer side. In addition, since the dispersibility of the low alumina-containing ore of the brand C can be improved, it is possible to suppress the fine particles of the low alumina-containing ore of the brand C from condensing into a dumpling.
Therefore, even when the ores of each of the brands A to C are arranged in multiple layers at a predetermined ratio to form the blending mountain 19, the particles of the low alumina-containing ore of the brand C having high adhesion can be prevented from condensing. . For this reason, when the blending reclaimer 20 cuts from the blending mountain 19, as shown in FIG. 3 (b), the particles of the brand A high alumina-containing ore, the particles of the brand B fine ore, and the brand C Blending powder (B powder) in which particles of low alumina-containing ore are uniformly blended is formed.

For this reason, blending powder (B powder) is mixed and granulated by the drum mixers 22 and 23 to form a pseudo-particulate sintered raw material, and this sintered raw material is accommodated in the surge hopper 32.
In the sintering machine pallet 31, the sintering material cut out by the roll feeder 33 from the surge hopper 32 that stores the sintering material is charged onto the sintering machine pallet 31 by the slowing chute 34, and the sintering material charging layer. 35 is formed.

  The sloping chute 34 is cut by the roll feeder 33 and receives a sintering raw material that falls from the traveling direction side of the sintering machine pallet 31 and receives the sintering raw material on the sintering machine pallet 31 in a direction opposite to the traveling direction of the sintering machine pallet 31. It is inclined to the upper right so as to be charged toward the front. In this case, the inclination angle is set to be greater than the repose angle determined by the moisture content of the sintered raw material.

An ignition furnace 36 for igniting the surface layer of the sintered raw material from above is provided downstream of the roll feeder 33 by a predetermined distance in the direction of conveying the raw material. As shown in FIG. 1, the sintering raw material is ignited by the ignition furnace 36, and air is sucked from above the sintering raw material layer 35 by the main exhaust fan 38 from the wind box 37 below the sintering machine pallet 31. The ligation process is started.
In this sintering step, the combustion / melting zone of the charging layer 35 formed by igniting the carbon material in the surface layer portion of the charging layer 35 in the ignition furnace 36 is sucked by the wind box 37 to sinter. As the machine pallet 31 moves, it is sequentially moved to the lower layer side of the charging layer 35 to form a sintered cake.

The formed sintered cake is discharged from the exhausted portion formed on the most downstream side of the sintering machine pallet 31, cooled by a cooler, crushed and sized, and an agglomerate of 5.0 mm or more is formed. Collected as a product sinter, agglomerates of less than 5.0 mm are returned to the return hopper as return ore.
Thus, in the sintering raw material charging layer 35 fired on the sintering machine pallet 31, as shown in FIG. 3 (b), the high alumina content ore of the brand A, the fine ore of the brand B, and the adhesion The high-aluminum grade C low-alumina content ore is uniformly mixed and fired, and the high-adhesion grade C high-alumina content ores condense together to form a lump. It does not hinder the physical gas flow in the layer 35, and the fluidity of the melt due to the uneven distribution of the high alumina-containing ore is reduced. As a result, it is possible to obtain ore and improve the yield.

  By the way, in the case where the adhesion inhibitor by the polymer flocculant is not added to the low alumina content ore of the brand C, as shown in FIG. 3 (a), the low alumina content ore of the brand C is piled up. Due to the high adhesion of the containing ore, the particles of the low alumina-containing ore adhere to each other and form a dumpling-like lump. The low-alumina-containing ore that has become this agglomerate is in the form of blending powder (B-powder) mixed with ores of other brands A and B, as shown in FIG. The material is not decomposed, and the grade C low alumina-containing ore is unevenly distributed.

  The uneven distribution of the low alumina content ore of the brand C is continued in the sintering raw material charging layer 35 formed on the sintering machine pallet 31, and in this state, the surface layer of the sintering raw material charging layer 35. When the carbon material is added to the carbon material and firing is started, as shown in FIG. 4 (a), the physical gas flow is inhibited by the brand C, which is a dumpling-like lump, and the other portions are relative. In particular, the high alumina state lowers the fluidity of the melt, impedes aeration, and lowers the strength due to insufficient firing. Thereby, the yield of a product sintered ore falls. In order to solve this, it is conceivable to grind the low alumina-containing ore lump using a mixer having a function of crushing the low alumina-containing ore lump. The number of equipment will increase and it will be difficult to add a new mixer to the existing equipment.

  However, according to the present embodiment, it is possible to prevent the formation of a lump by adding an adhesion inhibitor to the low alumina-containing ore of the brand C having high adhesion, thereby increasing the dispersibility. C can be mixed uniformly, and blending powder (B powder) in which brand C, which is a low alumina-containing ore, is evenly mixed with brand A, which is a high-alumina-containing ore, can be obtained, and firing is started. Even when it is done, as shown in FIG. 4 (b), the low alumina-containing ore can be dispersed without becoming an agglomerate to reliably prevent the high alumina-containing ore from being unevenly distributed. Therefore, the air permeability in the sintering process can be secured to prevent the strength from being lowered due to insufficient firing, and the yield of the product sintered ore can be improved. Moreover, it is not necessary to provide a step of pulverizing the lump of the low alumina-containing ore using a mixer having a pulverizing function in the process of forming the sintered raw material.

For this reason, when blending powder is charged onto the sintering machine pallet 31 to form the sintering raw material charging layer 35, the air permeability of the sintering raw material charging layer 35 is shown in FIG. In addition, it is possible to suppress the lowering of the fluidity of the melt and to perform satisfactory firing to eliminate the lack of firing. For this reason, the yield of a product sintered ore can be improved.
Here, the particles of brand A high alumina-containing ore and the particles of brand C low alumina-containing ore are blended 1: 1, and the blending of other powder coke and auxiliary raw materials is the same. FIG. 5 shows the results of a sintering pot experiment in which the polymer flocculant as an adhesion inhibitor is not added to the low alumina-containing ore particles and in the case where no polymer flocculant is added.

  As is apparent from FIG. 5, in the experimental result T1 when the polymer flocculant is not added to the brand C, which is a low alumina-containing ore, the product yield [%] having a particle diameter of 10 mm is about 66.9 [%]. On the other hand, in the experimental result T2 when the polymer flocculant is added to the brand C, which is a low-alumina-containing ore, the product yield [%] with a particle size of 10 mm is 69.3 [%], The product yield was improved by 2.4% compared to the case where no agent was added.

  In the above-described embodiment, the case where the adhesion inhibitor is added at the upper end of the stacker boom conveyor 14 when stacking the low alumina-containing ore of the brand C has been described. However, the present invention is not limited to this. When unloading from a transport ship with an unloader, a polymer flocculant can be added, or a polymer flocculant can be added during the transport of the unloaded grade C low alumina-containing ore on a belt conveyor. A predetermined amount of a polymer flocculant may be added to the particles of brand C low alumina-containing ore before blending powder (B) powder.

  Further, in the above embodiment, the brands A to C are piled up separately, paid out from the brands A to C using the reclaimer 17 to form a multi-layered blending mountain 19, and the blending mountain 19 is blended with the blending reclaimer 20. However, the present invention is not limited to this. That is, each brand A to C piled up individually is individually stored in an iron ore hopper, and an appropriate amount is cut out from each iron ore hopper and mixed into a drum mixer or the like while mixing on a belt conveyor. It may be.

DESCRIPTION OF SYMBOLS 11 ... Ore carrier, 12 ... Unloader, 13 ... Horizontal conveyor, 14 ... Stacker boom conveyor, 15 ... Ore stock yard, 16 ... Adhesion inhibitor, 17 ... Reclaimer, 18 ... Blending stacker, 19 ... Blending mountain, 20 ... Blending reclaimer, 21A ... Bending powder hopper, 21B ... Returning hopper, 21C ... Carbon hopper, 21D ... Sub-material hopper, 22,23 ... Drum mixer, 31 ... Sinter pallet, 32 ... Surge hopper, 33 ... Roll Feeder 34 ... Slowing chute 35 ... Sintering raw material charging layer 36 ... Ignition furnace 37 ... Wind box

Claims (4)

Formed by kneading the blended powder with at least a blend of high alumina content ore with high alumina content and low alumina content ore with lower alumina content than the high alumina content ore and auxiliary materials When the sintered raw material is charged into a moving pallet and fired, the additive containing the polymer flocculant as a main component is added to the low-alumina-containing ore as an adhesion inhibitor . The addition amount is larger than the addition amount exhibiting the agglomeration action, and is added so that the addition amount can suppress the crosslinking action of the polymer flocculant in a state where moisture contained in the low alumina-containing ore is not separated , and at least the low A processing method of a sintering raw material, characterized in that an alumina-containing ore and a blending powder in which the high alumina-containing ore is uniformly dispersed are obtained. The processing method of the sintering raw material according to claim 1 , wherein the addition amount of the polymer flocculant is in the range of 0.01 to 0.1% of the water content of the low alumina-containing ore. The low alumina-containing ore is less 1.65% of the total alumina content, the high alumina-containing ore, claim 1, wherein the alumina content is greater than 1.65% of the total Or the processing method of the sintering raw material of 2 . Addition to the low alumina-containing ore of the adhesion inhibitor, at least the lower alumina-containing ore with any one of claims 1 to 3, characterized in that before mixing the high alumina-containing ore The processing method of the sintering raw material as described in 2.

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