JP6188022B2 - Slag manufacturing method and slag manufacturing system - Google Patents

Description

The present invention relates to a manufacturing system for manufacturing process and slag of the slag.

  Ferronickel is an alloy of iron and nickel, and is used as a raw material for stainless steel and special steel. As a general manufacturing method of ferronickel, there is a dry smelting method using nickel oxide ore as a raw material and having a preliminary drying step, a firing and partial reduction step, a reduction melting step, a desulfurization step, and a casting step. It is done.

  Specifically, a method for producing ferronickel by a dry smelting method will be described for each step.

  First, in the preliminary drying step, after blending the raw material ore so as to have a predetermined mixing ratio, a part of the adhering moisture in the ore is removed by a rotary dryer. Specifically, the moisture in the ore is from 35 to 45% to 25 to 35%. Hereinafter, the ore obtained in the preliminary drying step is referred to as “dry ore”.

  Next, in the calcination and partial reduction step, a carbonaceous reducing agent (coal) and a melt as necessary are added to the dried ore obtained in the preliminary drying step, and the resulting mixture is put into a rotary kiln and In addition to completely removing the remaining moisture (adhesion water, crystal moisture) in the dry ore, a partially reduced calcined ore (hereinafter referred to as “calcined ore”) (800 to 900 ° C.) is produced, Drain with remaining reducing agent.

  Next, in the reduction melting step, the sinter obtained in the firing and partial reduction step is put into a reduction furnace such as an electric furnace or a blast furnace, and the firing obtained in the firing and partial reduction step in the reduction furnace. The ore is reduced and melted to form crude ferronickel (metal) and slag. The crude ferronickel produced in this reduction furnace contains iron as the main component, contains 16 to 25% by weight of nickel according to the set amount of the carbonaceous reducing agent, and contains a large amount of sulfur derived from fuel. Contains impurities.

  The crude ferronickel obtained in the reduction melting process is moved to the desulfurization process when desulfurization treatment is required according to the product specifications, and a mechanical stirring device or an electric induction stirring device using a ladle or the like. The desulfurization process by is performed and becomes refined ferronickel.

  In the casting process, the refined ferronickel melt obtained in the desulfurization process is poured into a mold, or coarsened through a rotating disk-shaped medium, and then cooled to cool an ingot or flaky ferronickel ( Product).

  On the other hand, in the above-described reduction melting step, the slag produced separately from the crude ferronickel is discharged from the reduction furnace to the water granule as a molten slag of about 1500 ° C. The molten slag discharged to the water slag is crushed by contact with a large amount of water flowing in the water slag and simultaneously cooled to 100 ° C. or less, and is crushed into fine particles to form a granulated slag.

  The granulated slag obtained in this way contains most of the iron oxide in the raw ore and silicon dioxide and magnesium oxide, is glassy and chemically stable, and does not dissolve the contained elements. In addition to being an excellent material, it has many characteristics such as high magnesium oxide, hard material, high specific gravity, etc., so magnesia for component adjustment in steel sintering process, fine aggregate for concrete, civil engineering work It is used as materials for boilers, fluidized bed materials for boilers, etc.

  When the granulated slag is used for the above-mentioned application, the required coarse particle ratio is almost determined according to the application, and therefore, it is necessary to have a predetermined particle size according to the application. The coarse grain ratio means that the granulated slag is classified using, for example, a 2.36 mm, 1.18 mm, 0.60 mm sieve, and when this value is plotted on a Rosin-Rammler diagram, the cumulative mass becomes 50%. The particle diameter is sometimes abbreviated as D50.

  However, since the granulated slag uses water in the process of obtaining it, the obtained granulated slag contains about 8 to 10% of water, and is also a massive granulated slag or a fine granulated slag having a particle diameter of less than 1 mm. Contains granulated slag. For this reason, there has been a problem that granulated slag adheres to the transportation equipment or the grinding equipment or the equipment is damaged during the transportation or grinding.

  On the other hand, in Patent Document 1, as a method for producing fine powder slag from molten blast furnace slag, a mixed fluid of cooling water and air is sprayed on the molten blast furnace slag to rapidly cool the blast furnace slag, and the vitrification rate is 95% or more. A technique is disclosed in which sand-like slag is produced, and the sand-like slag is fluid-transported continuously to the roller mill by the mixed fluid.

  However, the technique described above relates to blast furnace slag having a relatively low specific gravity in steel smelting, and cannot be directly applied to ferronickel slag in ferronickel smelting.

JP-A-7-54022

The present invention has been proposed in view of such circumstances, and when conveying or pulverizing the granulated slag, by controlling the moisture in the granulated slag and aligning the particle size of the granulated slag, and to provide a manufacturing system of the production process and the slag of the slag can be suppressed that the granulated slag to the transport equipment and milling equipment to or equipment attached is damaged.

  In the method for producing slag according to the present invention, the composition of the obtained slag is CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less. As described above, a blending step of blending a plurality of nickel oxide ores at a predetermined blending ratio, a preliminary drying step of generating a dry ore by removing a part of adhering moisture in the ore obtained in the blending step, and the above The remaining moisture in the dried ore obtained in the preliminary drying process is completely removed and the partially reduced calcined or partially reduced calcined ore, and the calcined ore obtained in the above calcined and partially reduced processes are reduced and melted. The molten slag obtained by the reduced melting step and forming the molten slag, and the molten slag obtained in the reduced melting step is subjected to water granulation under a water granulated water amount / molten slag amount of 10 to 40 and a coarse particle ratio of 5 mm or less. A water granulation process for producing granulated slag and the water A moisture control step of reducing the moisture content of the granulated slag having a coarse particle ratio of 5 mm or less obtained in the step to 4% or less, and a pulverizing step of pulverizing the granulated slag obtained in the moisture control step, In the moisture control step, the water granulated slag obtained in the above-mentioned water granulation step is conveyed by the belt conveyor, the water adhering to the granulated slag is separated, and the water granulated water is separated by the belt conveyor. Place the slag in the granulated slag storage area to reduce the water content of the granulated slag to 4% or less.

  In the slag production system according to the present invention, the composition of the obtained slag is CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less. As described above, a blending facility that blends a plurality of nickel oxide ores at a predetermined blending ratio, a rotary dryer that generates dry ore by removing some of the adhering moisture in the ore obtained by the blending facility, and the rotary A rotary kiln that completely removes the remaining moisture in the dried ore obtained by the dryer and generates partially reduced calcined ore; and a reduction furnace that forms a molten slag by reducing and melting the calcined ore obtained by the rotary kiln. The granulation mechanism for granulating the molten slag obtained in the reduction furnace under the condition that the amount of granulated water / molten slag is 10 to 40 to produce granulated slag having a coarse particle ratio of 5 mm or less, and the above water A water control mechanism that reduces the water content of the granulated slag obtained by the mechanism to 4% or less, and a pulverizer that crushes the water granulated slag obtained by the water control mechanism. A belt conveyor that separates the water adhering to the granulated slag while conveying the granulated slag obtained by the mechanism, and a granulated slag storage place where the granulated slag from which the water has been separated is placed It consists of

  According to the present invention, when conveying or pulverizing the granulated slag, the granulated slag adheres to the conveying facility and the pulverizing facility by controlling the moisture in the granulated slag and adjusting the particle size of the granulated slag. Or it can suppress that an installation breaks.

It is the flowchart figure which showed the manufacturing method of the slag to which this invention is applied. It is the perspective view which showed the 1st belt conveyor. It is the side view which showed the transfer part of the belt conveyor. It is the perspective view which showed the sieve. It is the perspective view which showed the chute | shoot part.

  Hereinafter, a slag manufacturing method, a slag manufacturing system, and a slag to which the present invention is applied will be described in detail with reference to the drawings. In addition, this invention is not limited to the following examples, It can change arbitrarily in the range which does not deviate from the summary of this invention.

  As shown in FIG. 1, a slag manufacturing system 1 to which the present invention is applied includes a blending facility 10, a rotary dryer 20, a rotary kiln 30, a reduction furnace 40, a water granulating mechanism 50, and a first belt conveyor 60. And the 1st granulated slag storage place 70, the crusher 80, and the 2nd granulated slag storage place 90 are provided.

  The slag to which the present invention manufactured by the slag manufacturing system 1 is applied is a ferronickel slag obtained when smelting ferronickel, and the composition of the slag is CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less, containing most of the iron oxide in the raw ore and silicon dioxide and magnesium oxide, and chemically stable with glassy In addition to being an environmentally superior material such as no elution of contained elements, it has many characteristics such as high magnesium oxide, hard material, and high specific gravity. Therefore, the slag to which the present invention is applied is used as a magnesia melt for adjusting components in a steel sintering process, a fine aggregate for concrete, a material for civil engineering work, a fluidized bed material for boilers, and the like.

  And the said slag is manufactured as follows using the manufacturing system 1 of slag.

  Specifically, the slag manufacturing method to which the present invention is applied includes a blending step, a preliminary drying step, a firing and partial reduction step, a reduction melting step, a water granulation step, a first moisture control step, 2 moisture control steps, a pulverization step, and a final moisture control step.

  First, in the blending step, a plurality of nickel oxide ores that are raw materials are blended at a predetermined blending ratio by the blending facility 10 that functions as a blending means. Specifically, the nickel oxide ore has a slag composition of CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less. To be blended.

  Next, in the preliminary drying step, the ore obtained in the blending step is put into a rotary dryer 20 that functions as a preliminary drying means, and the rotary dryer 20 removes a part of the adhering moisture in the ore obtained in the blending step. Remove. Specifically, in the preliminary drying step, the water content in the ore is 35 to 45% to 25 to 35%. Hereinafter, the ore obtained in the preliminary drying step is referred to as “dry ore”.

  Next, in the calcination and partial reduction process, a carbonaceous reducing agent (coal) and, if necessary, a melt are added to the dried ore obtained in the preliminary drying process to function as a calcination and partial reduction means. The rotary kiln 30 is charged with the remaining moisture (adherent water, crystal moisture) in the dry ore, and the partially reduced calcined ore (hereinafter referred to as “calcined ore”). 800-900 ° C.) and discharged with the remaining reducing agent.

  Next, in the reduction melting step, the sinter obtained in the firing and partial reduction step is put into a reduction furnace 40 such as an electric furnace or a smelting furnace functioning as a reduction melting means. The burned ore obtained in the partial reduction process is reduced and melted to form crude ferronickel (metal) and slag. At this time, the slag temperature is preferably adjusted by the reduction furnace 40 to 1500 to 1650 ° C. Thereby, in the reduction melting step, a slag having a low viscosity, that is, a viscosity of 50 poise or less can be obtained.

  Next, in the water granulation step, the slag formed in the reduction melting step is discharged as a molten slag of about 1500 ° C. from the reduction furnace 40 to the water granule 51 of the water granulation mechanism 50. The molten slag discharged to the granulated slag 51 is crushed by contact with a large amount of water flowing through the slag 51, and at the same time, rapidly cooled to 100 ° C. or less, crushed into fine particles and crushed slag. And stored in the granulation pit 52 of the granulation mechanism 50.

  At this time, the slag obtained in the reduction furnace 40 is preferably discharged from the reduction furnace 40 to the water granule 51 through a slag hole having an inner diameter of 60 to 120 mm.

  Furthermore, since the slag obtained in the reduction furnace 40 has a low viscosity, the water granule 51 is caused to flow at a flow rate of 100 to 300 t / h. By setting it as such a flow velocity, the thickness of the flux of the slag which flows through this water granule 51 is substantially constant, and the thickness of the flux can be made thin.

  When the amount of molten slag is less than 100 t / h, since the amount of molten slag flowing through the water slag 51 is small, the amount of adhesion to the water slag 51 is increased or the production efficiency is lowered, which is not preferable.

  When the amount of molten slag exceeds 300 t / h, the amount of molten slag flowing through the water slag 51 is large. Therefore, when the amount of molten slag fluctuates in the increasing direction, troubles such as overflow from the water slag 51 may occur. It is not preferable because the property increases.

  In addition, the slag flux with the slag flux thickness being almost constant and the slag flux thickness being thin can be obtained by subjecting the slag flux to a water granulated water / melted slag amount of 10-40. The particle size of the granulated slag can be made uniform. Specifically, granulated slag having a coarse particle ratio of 5 mm or less can be obtained.

  When the amount of granulated water / melted slag is less than 10, since the amount of water is small, the molten slag may be deeper than the surface of the granulated water. If the molten slag is submerged deeper than the surface of the granulated water, it is not preferable because it may cause a steam explosion and seriously damage the equipment. Moreover, since granulated water cannot be uniformly applied with respect to the flux of molten slag, granulated slag with a large particle size may arise.

  When the amount of granulated water / melted slag exceeds 40, the amount of granulated water is sufficient, so there is no problem in obtaining the granulated slag itself. However, since a large amount of granulated water is supplied, the power cost for supplying the granulated water increases, which is not preferable. Moreover, after granulating, fine granulated slag having a particle diameter of less than 1 mm is produced, the proportion of the fine granulated slag is increased, and the proportion of 1 to 5 mm of granulated slag is decreased.

  Here, when the granulated slag has a coarse particle ratio of 5 mm or less, it adheres to various places when the water content is 8% or more. When the water content is less than 8%, the adhesion decreases, and when it is 4% or less, it does not adhere reliably. The applicant of the present invention found out empirically. However, the granulated slag immediately after being obtained in the granulation step has a water content of 8% or more, and thus adheres to various places. Therefore, the water content of the granulated slag obtained in the water granulation step is adjusted to 4% or less as described later.

  Next, in the first moisture control step, the granulated slag obtained in the granulation step is composed of at least one belt conveyor 61 that functions as a first moisture control means and serves as a first transport facility. The first belt conveyor 60 is used to separate water adhering to the granulated slag while transporting from the granulated pit 52 to the first granulated slag storage area 70.

  Specifically, after the granulated slag is conveyed from the granulation pit 52 to the belt 63 moving on the carrier roller 62 of the belt conveyor 61 by the bucket conveyor 53 of the granulation mechanism 50 as shown in FIG. Then, it is carried on this belt 63. Since the belt 63 sinks due to the load of the granulated slag, there is a step between the place W1 where the carrier roller 62 is present and the place W2 where the carrier roller 62 is not present, so that the granulated slag placed on the belt 63 is carried while swinging up and down. It is. When transported while shaking, a part of the water adhering to the granulated slag is separated. At this time, the granulated slag is preferably placed on a belt conveyor 61 having a length of 10 m or more. If the length of the belt conveyor 61 is 10 m or more, the water in the granulated slag is sufficiently separated. Can do.

Then, on the belt 63, a pulverized slag mountain 2 and a water reservoir 3 made of moisture are formed around the mountain 2. As shown in FIG. 3, the water separated from the granulated slag is a heavy granulated slag having a specific gravity of about 3 g / cm ³ at the end of the belt conveyor 61, that is, the transfer portion 64 of the belt conveyor 61. As shown by an arrow A in the middle, water having a specific gravity of about 1 g / cm ³ that has been blown away is used to fall close to the transfer portion 64 as shown by an arrow B in FIG. The distance x between the front belt conveyor 61a and the rear belt conveyor 61b is adjusted, and only the granulated slag is placed on the rear belt conveyor 61b from the front belt conveyor 61a. Thus, the 1st belt conveyor 60 isolate | separates the water | moisture content adhering to the granulated slag efficiently, conveying the granulated slag obtained at the granulated process.

  Next, as shown in FIG. 1, in the second moisture control step, the granulated slag from which moisture has been separated in the first moisture control step is used as a first slag storage 70 that functions as a second moisture control means. To ensure that the water content of the granulated slag is 4% or less. Specifically, in this step, the water content of the granulated slag was reduced to 4% or less, and 24 hours or more were obtained after the granulated slag was obtained.

  Next, in the pulverization step, the granulated slag obtained in the second moisture control step is pulverized from the first granulated slag storage site 70 by the second transport facility 100 constituted by a second belt conveyor or the like. It conveys to the grinder 80 which functions as a means, and crushes with the grinder 80 so that it may become a predetermined particle size according to a use. At this time, since the granulated slag has a coarse particle ratio of 5 mm or less and a moisture content of 4% or less by the first moisture control step and the second moisture control step, the second transport equipment 100 and the pulverizer 80 are used. Adhering to can be suppressed.

  Specifically, the pulverizer 80 includes at least one of a rotor mill, a rod mill, a ball mill, and a roller mill.

  In the case where the granulated slag is pulverized by the pulverizer 80, the pulverized slag may be pulverized while adding 10 to 80 L / slag t of water to the side wall in the pulverizer 80.

  When the granulated slag is pulverized by the pulverizer 80, a fine granulated slag may be formed. This fine granulated slag adheres to, for example, the side wall in the pulverizer 80 and reduces the pulverization efficiency. Therefore, in order to suppress this adhesion, the granulated slag is pulverized while adding 10 to 80 L / slag t of water to, for example, the side wall in the pulverizer 80 according to the degree of adhesion. Then, in the pulverizer 80, adhesion of this fine granulated slag can be suppressed.

  When the amount of water added is less than 10 L / slag t, since the amount of water added is small, the effect of suppressing the adhesion of this fine granulated slag is small. Moreover, when the addition amount of water exceeds 80 L / slag t, excess water will be contained in the obtained granulated slag.

  Next, in the final moisture control step, since the granulated slag obtained in the grinding step contains more than 4% moisture, the granulated slag obtained in the grinding step is constituted by a third belt conveyor or the like. 3 is transferred from the pulverizer 80 to the second granulated slag storage 90 which functions as the final moisture control means, and is then placed in the second granulated slag storage 90, where the water content of the granulated slag is 4 % Or less. Specifically, in this step, the water content of the granulated slag was reduced to 4% or less, and 24 hours or more were obtained after the granulated slag was obtained in the pulverization step.

  As described above, the slag to which the present invention is applied is manufactured using the slag manufacturing system to which the present invention is applied.

  In addition, when the 3rd conveyance equipment 110 is a 3rd belt conveyor, it is obtained by a 3rd belt conveyor at a grinding | pulverization process similarly to the 1st belt conveyor 60 as a 3rd moisture control process. The water granulated slag may be separated from the water granulated slag while being transported from the pulverizer 80 to the second granulated slag storage 90.

  As described above, in the slag manufacturing method and slag manufacturing system to which the present invention is applied, the molten slag obtained in the reduction furnace 40 by the granulation mechanism 50 is converted into the amount of granulated water / the amount of molten slag. Is crushed under 10 to 40 to produce a granulated slag having a coarse particle ratio of 5 mm or less. In the first moisture control step, the water obtained by the granulation step by the first belt conveyor 60 While separating the crushed slag and the moisture adhering to the granulated slag, in the second moisture control step, the granulated slag from which moisture has been separated in the first moisture control step is supplied to the first slag storage 70. By setting the water content of granulated slag with a coarse particle ratio of 5 mm or less to 4% or less, it is possible to prevent the granulated slag in the middle of production from adhering to the conveying equipment and the crusher equipment and damaging these equipment. be able to. Therefore, according to the slag manufacturing method and the slag manufacturing system to which the present invention is applied, the slag can be efficiently manufactured.

  Furthermore, in the slag manufacturing method and slag manufacturing system to which the present invention is applied, in the pulverization step, water is added to the side wall in the pulverizer 80 while pulverizing while adding 10 to 80 L / slag t. When crushing crushed slag, adhesion of granulated slag can be suppressed. Therefore, according to the slag manufacturing method and the slag manufacturing system to which the present invention is applied, the slag can be efficiently manufactured.

  Furthermore, in the slag manufacturing method and slag manufacturing system to which the present invention is applied, in the final moisture control step, the granulated slag obtained in the pulverization step is placed in the second slag storage 90 for 24 hours or more, and the granulated slag By making the moisture of 4% or less, it is possible to suppress adhesion to the subsequent transfer equipment, and workability is good.

  Furthermore, the slag to which the present invention is applied has a slag composition of CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less, The water content of the granulated slag obtained by the water granulation mechanism 50 in the crushing process is 4% or less. Therefore, according to the slag to which the present invention is applied, it is possible to suppress adhesion to the conveyance facility and pulverizer facility and damage to these facilities.

  As shown in FIG. 4, the first belt conveyor 60 may be provided with a sieve 120 having an opening S of 10 to 100 mm at least at the entrance of the belt conveyor 61. The granulated slag is also mixed with slag that has been peeled off after adhering to the granulated slag 51 and solidifying. The peeled slag may damage equipment such as the belt conveyor 61. Therefore, for example, the belt conveyor 61 of the first belt conveyor 60 may be provided with a sieve 120 having an opening S of 10 to 100 mm at the entrance.

  When the opening S is less than 10 mm, it is difficult to pass granulated slag of 100 t / hour or more. Moreover, when the opening S exceeds 100 mm, since a large granulated slag lump is mixed, it is not preferable.

  Furthermore, the sieve 120 is preferably a grizzly type in which the rail materials 121 are arranged vertically at equal intervals so that the granulated slag lump on the sieve 120 can be easily removed from the sieve 120, for example.

  Furthermore, in addition to the first belt conveyor 60, the second belt conveyor and / or the third belt conveyor may be provided with a sieve 120 having the same or different opening S. Furthermore, the sieve 120 may be provided only on the second belt conveyor or the third belt conveyor.

  Therefore, when the sieve 120 having the opening S of 10 to 100 mm is provided at the entrance of the belt conveyor in this way, it is possible to more reliably suppress the granulated slag from damaging the transport facility and the pulverizer facility. It is possible to produce the granulated slag more efficiently.

  Further, as shown in FIG. 5, the vibrator 130 may be attached to the transfer portion 64 of the belt conveyor 61 of the first belt conveyor 60.

  The granulated slag easily adheres to the transfer portion 64 of the belt conveyor 61, specifically, the conveyor outlet chute portion 65. Accordingly, it is preferable to attach the vibrator 130 to the conveyor drop chute portion 65. For example, when the conveyor drop chute portion 65 has a square cross section, one vibrator 130 may be attached to each of the four surfaces.

  Furthermore, in addition to the first belt conveyor 60, the vibrator 130 may be attached to the conveyor drop chute portion of the transfer portion of the second belt conveyor and / or the third belt conveyor. Furthermore, you may make it attach the vibrator 130 only to the conveyor drop chute part of the transfer part of a 2nd belt conveyor or a 3rd belt conveyor.

  Therefore, when the vibrator 130 is attached to the transfer part of the belt conveyor as described above, it is possible to prevent the granulated slag from adhering to the transfer part, and the granulated slag can be manufactured more efficiently.

Example 1
In Example 1, in the ferronickel smelting, the composition of the slag obtained is CaO: 15.0%, MgO: 40.0%, S: 0.5%, Fe: 8.5% A plurality of nickel oxide ores as raw materials were prepared at a predetermined preparation ratio.

  The prepared ore was transferred to a reduction melting step using a reduction furnace through a preliminary drying step using a rotary dryer, firing using a rotary kiln and a partial reduction step, and was melted.

  In the reduction melting step, the slag temperature was adjusted to 1500 ° C. by adjusting the electric power supplied to the reduction furnace.

  The molten slag obtained in the reducing furnace was discharged from the reducing furnace to the water granulated slag at 100 t / h, and water granulated under the condition of the amount of water crushed water / the amount of molten slag 10 to obtain a granulated slag.

  The obtained granulated slag was conveyed to the first granulated slag storage area by a first belt conveyor having a length of 10 m. The granulated slag transported to the first granulated slag yard was placed in the first granulated slag yard for 24 hours and then crushed by a pulverizer.

  The belt conveyor was provided with a grizzly type sieve having an opening of 10 mm at the entrance. In addition, a chute having a square cross section is attached to the conveyor drop chute, and one vibrator is attached to each of the four surfaces.

  As the pulverizer, a rotor mill was used. During the pulverization, 10 L / slag t of water was added to the side wall of the rotor mill.

  At this time, there was almost no adhesion of the granulated slag to the equipment, and there was no damage to the equipment, and the granulated slag could be obtained.

(Example 2)
In Example 2, the slag temperature of the reducing furnace is 1650 ° C., the amount of molten slag discharged from the reducing furnace to the granulated slag is 300 t / h, the amount of granulated water / the amount of molten slag during granulation is 40, and the sieve opening is The same operation as in Example 1 was performed except that the amount of water added to the side wall in the rotor mill was 80 L / slag t.

  In this case, there was almost no adhesion of the granulated slag to the equipment, and there was no damage to the equipment, and the granulated slag could be obtained.

(Comparative Example 1)
In Comparative Example 1, the obtained granulated slag was placed in the first granulated slag storage place for 6 hours and then pulverized by a pulverizer, and was performed in the same manner as in Example 1. The slag adhered to the pulverizer was marked and stopped every 10 minutes to remove the granulated slag. For this reason, the pulverization amount per hour was 50% of Example 1.

DESCRIPTION OF SYMBOLS 1 Production system, 10 preparation equipment, 20 rotary dryer, 30 rotary kiln, 40 reduction furnace, 50 granulation mechanism, 51 granulation tank, 52 granulation pit, 53 bucket conveyor, 60 1st belt conveyor, 61 belt conveyor, 61a Front belt conveyor, 61b Rear belt conveyor, 62 Carrier roller, 63 belt, 64 Transfer part, 65 Conveyor drop chute part, 70 1st granulated slag place, 80 grinder, 90 2nd granulated slag place, 100 2nd conveying equipment, 110 3rd conveying equipment, 120 sieve, 130 vibrator

Claims (10)

Predetermining a plurality of nickel oxide ores so that the composition of the obtained slag is CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less A blending process of blending at a blending ratio of
A pre-drying step of removing a part of the adhering moisture in the ore obtained in the blending step to produce a dry ore;
A calcination and partial reduction step for completely removing the remaining moisture in the dry ore obtained in the preliminary drying step and generating a partially reduced baked ore;
A reducing and melting step of forming a molten slag by reducing and melting the calcined ore obtained in the firing and partial reduction steps;
A granulation step of producing a granulated slag having a coarse particle ratio of 5 mm or less by granulating the molten slag obtained in the reduction melting step under an amount of granulated water / molten slag of 10 to 40;
A moisture control step in which the moisture content of the granulated slag having a coarse particle ratio of 5 mm or less obtained in the above-mentioned granulation step is 4% or less;
And crushing the granulated slag obtained in the moisture control step,
In the moisture control step, the water adhered to the granulated slag is separated while the granulated slag obtained in the granulating step is conveyed by a belt conveyor, and the water from which the moisture has been separated by the belt conveyor is separated. A method for producing slag, wherein the crushed slag is placed in a granulated slag yard, and the water content of the granulated slag is reduced to 4% or less.   The slag manufacturing method according to claim 1, wherein the belt conveyor has a length of 10 m or more.   3. The granulated slag storage site is characterized in that the granulated slag from which water has been separated by the belt conveyor is placed for 24 hours or more after the granulated slag is obtained in the granulating step. The manufacturing method of slag as described in 2.   The slag manufacturing method according to any one of claims 1 to 3, wherein the belt conveyor is provided with a sieve having an opening of 10 to 100 mm at an entrance of the belt conveyor.   The slag manufacturing method according to any one of claims 1 to 4, wherein the belt conveyor includes a plurality of belt conveyors, and a vibrator is attached to a transfer portion of the belt conveyor.   The slag manufacturing method according to any one of claims 1 to 5, wherein in the pulverizing step, a pulverizer including at least one of a rotor mill, a rod mill, a ball mill, and a roller mill is used.   The said pulverizer grind | pulverizes the said granulated slag, adding 10-80L / slag t of water to an internal side wall, The manufacturing method of the slag of Claim 6 characterized by the above-mentioned. And further having another moisture control step for reducing the moisture content of the granulated slag obtained in the above grinding step to 4% or less,
In the other moisture control step, the granulated slag obtained in the pulverization step is placed in another granulated slag storage area for 24 hours or more after the granulated slag obtained in the above pulverization step is pulverized, and the water content of the granulated slag obtained in the above pulverization step is 4 % Or less, The manufacturing method of the slag of Claim 7 characterized by the above-mentioned.   In the said reduction | melting melting process, it adjusts so that slag temperature may be 1500-1650 degreeC with a reducing furnace, The manufacturing method of the slag in any one of the Claims 1 thru | or 8 characterized by the above-mentioned. Predetermining a plurality of nickel oxide ores so that the composition of the obtained slag is CaO: 15.0% or less, MgO: 40.0% or less, S: 0.5% or less, Fe: 8.5% or less A blending facility for blending at a blending ratio of
A rotary dryer that generates dry ore by removing some of the adhering moisture in the ore obtained by the above blending equipment;
A rotary kiln that completely removes the remaining moisture in the dried ore obtained by the rotary dryer and generates a partially reduced calcined ore;
A reduction furnace for reducing and melting the calcined ore obtained in the rotary kiln to form a molten slag;
A granulation mechanism for granulating the molten slag obtained in the reduction furnace under a water granulated water amount / molten slag amount of 10 to 40 to produce a granulated slag having a coarse particle ratio of 5 mm or less;
A moisture control mechanism that reduces the moisture content of the granulated slag obtained by the above-described granulation mechanism to 4% or less;
A crusher for crushing the granulated slag obtained by the moisture control mechanism,
The moisture control mechanism includes a belt conveyor that separates moisture adhering to the granulated slag while conveying the granulated slag obtained by the granulating mechanism, and a granulated water from which moisture has been separated by the belt conveyor. A slag production system comprising a granulated slag storage place where slag is placed.

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