JP7548073B2 - Method for smelting nickel oxide ore - Google Patents

Description

The present invention relates to a method for smelting nickel oxide ore, which produces ferronickel by reducing a mixture of nickel oxide ore, which is a raw material, and a carbonaceous reducing agent.

Known methods for smelting nickel oxide ores called limonite or saprolite include the dry smelting method, which uses a smelting furnace to produce nickel matte, the dry smelting method, which uses a rotary kiln or a moving hearth furnace to produce ferronickel, and the wet smelting method, which uses an autoclave to produce mixed sulfides.

When smelting nickel oxide ore, the raw ore is first treated to form agglomerates, slurry, etc. (pretreatment prior to reduction treatment). Specifically, in pretreatment, nickel oxide ore is agglomerated, that is, converted from a powder or fine particle form into agglomerates, by first mixing it with components other than nickel oxide ore, such as a binder and a reducing agent, to form a mixture, which is then fed into a lump-making machine after adjusting the moisture content, etc., to form agglomerates (pellets, briquettes, etc., hereafter simply referred to as "pellets") of, for example, about 10 mm to 30 mm in size.

For example, pellets need to have a certain degree of breathability to allow moisture to evaporate. Also, if reduction is not performed uniformly within the pellet, the composition will be non-uniform, and the metals may become dispersed and unevenly distributed. For this reason, it is important to mix the mixture uniformly and to maintain as uniform a temperature as possible during pellet reduction.

In addition, it is also important to coarsen the ferronickel produced by reduction. If the ferronickel produced is, for example, a few tens of microns to a few hundreds of microns in size, it becomes difficult to separate it from the slag, and the yield of ferronickel drops significantly. For this reason, a technology is needed to effectively coarsen the ferronickel produced after reduction.

In addition, in recent years, ores with high nickel content and few impurities have become scarce, so in order to produce high-quality ferronickel, it is necessary to efficiently process a variety of ores and accumulate data.

For example, a small amount of pellets are loaded into a reduction furnace, reduction treatment is performed, and the resulting reduced product is removed to examine various properties. However, the treatment temperature is high, around 1000°C to 1500°C, and loading and removing pellets is not easy. Conventionally, in such operations, pellets were loaded into the furnace and the resulting reduced product was removed using a special ladle made of a metal that can withstand relatively high temperatures, but the high temperature caused the ladle to bend, causing problems such as getting caught on the inner wall of the furnace when removing the pellets, which took more time than necessary and resulted in difficulty in obtaining accurate findings.

As described above, there are many problems remaining with the technology for producing metal by reducing a mixture containing nickel oxide ore, and a particularly important challenge is being able to perform various tests accurately and efficiently.

JP 2018-178252 A

The present invention has been proposed in light of these circumstances, and aims to provide a method for producing ferronickel by heating and reducing a mixture containing nickel oxide ore in a reduction furnace, which allows the mixture to be treated to be accurately and efficiently loaded into and removed from the reduction furnace, and prevents deterioration in the quality of the resulting metal.

After extensive research, the inventors discovered that the above-mentioned problems could be solved by using a sample ladle with a handle and a sample placement section connected to the end of the handle, placing a mixture sample on the sample placement section, and performing a reduction process while running a cooling medium through the inside of the handle, and thus completed the present invention.

(1) The first invention of the present invention is a method for smelting nickel oxide ore, which produces ferronickel by reducing a mixture containing nickel oxide ore as a raw material ore and a carbonaceous reducing agent, and includes a mixing process step of mixing the nickel oxide ore with the carbonaceous reducing agent, and a reduction process step of charging the mixture into a reduction furnace and heating the mixture to perform a reduction process, in which a sample ladle having a handle and a sample mounting portion connected to the tip of the handle is used in the reduction process, the mixture is placed on the sample mounting portion, and the reduction process is performed while a cooling medium is flowed inside the handle.

(2) The second invention of the present invention is a method for smelting nickel oxide ore according to the first invention, in which an inert gas is passed through the inside of the handle as the cooling medium.

(3) The third invention of the present invention is a method for smelting nickel oxide ore according to the first or second invention, in which the reduction step involves carrying out reduction treatment in the reduction furnace at a reduction temperature of 1200°C or higher and 1500°C or lower.

According to the present invention, in a technology for producing ferronickel by heating and reducing a mixture containing nickel oxide ore in a reduction furnace, a method can be provided that allows the mixture to be treated to be accurately and efficiently charged into and removed from the reduction furnace, and prevents deterioration in the quality of the resulting metal.

FIG. 1 is a process diagram showing an example of the flow of a method for smelting nickel oxide ore. FIG. 2 is a diagram showing an example of the configuration of a reduction furnace. FIG. 2 is a diagram showing an example of the configuration of a sample ladle.

A specific embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail below. Note that the present invention is not limited to the following embodiment, and various modifications are possible without departing from the gist of the present invention.

≪1. Nickel oxide ore smelting method≫
In the method for smelting nickel oxide ore according to the present embodiment, nickel oxide ore, which is a raw material ore, is mixed with a carbonaceous reducing agent, and the mixture is subjected to a reduction treatment in a smelting furnace (reduction furnace) to produce ferronickel metal and slag.

Specifically, the method for smelting nickel oxide ore includes at least a mixing process step of mixing nickel oxide ore with a carbonaceous reducing agent, and a reduction process step of loading the resulting mixture into a reduction furnace and heating the mixture to perform a reduction process.

In this case, the smelting method according to this embodiment is characterized in that in the reduction step, a sample ladle having a handle and a sample placement part connected to the end of the handle is used, and the mixture is placed on the sample placement part to load the mixture into the reduction furnace or remove it from the reduction furnace, while a cooling medium is passed through the inside of the handle while the reduction process is carried out.

By using a sample ladle in this way to carry out the reduction process, problems such as the reduction product being caught on the inner wall of the furnace can be prevented, particularly when removing the reduction product produced by the reduction process from the reduction furnace, and removal can be carried out smoothly. This makes it possible to produce ferronickel through efficient operations while suppressing deterioration in the quality of the reduction product, ferronickel metal.

≪2. About the smelting process≫
As described above, the method for smelting nickel oxide ore involves heating a mixture of nickel oxide ore, which is a raw material ore, and a carbonaceous reducing agent in a reduction furnace to reduce nickel (nickel oxide) and iron (iron oxide), thereby producing metal of an iron-nickel alloy (ferronickel).Ferronickel can be obtained by separating the metal from the reduction product obtained by the reduction process (separating the metal from the slag).

Specifically, as shown in FIG. 1, the nickel oxide ore smelting method according to the present embodiment includes a mixing process S1 in which a raw material containing nickel oxide ore is mixed with a carbonaceous reducing agent, a mixture forming process S2 in which the resulting mixture is formed into a predetermined shape, a reduction process S3 in which the formed mixture is reduced and heated at a predetermined reduction temperature in a reduction furnace, and a recovery process S4 in which the metal and slag generated in the reduction process S3 are separated and the metal is recovered.

[Mixing process]
The mixing process S1 is a process for mixing raw material powders including nickel oxide ore to obtain a mixture. Specifically, the raw material ore, nickel oxide ore, is mixed with a carbonaceous reducing agent, and powders having a particle size of, for example, about 0.2 mm to 0.8 mm, such as iron ore, flux components, and binders, are mixed as optional additives to obtain a mixture. The mixing process can be performed using a mixer or the like.

In the mixing process S1, kneading may be performed to improve mixability. For example, by kneading the mixture with a twin-screw kneader or the like, shear force is applied to the mixture, which breaks down aggregates of the carbonaceous reducing agent, raw material powder, etc., and allows for more uniform mixing. In addition, the adhesion of each particle can be increased, making it easier to perform a uniform reduction process on the resulting mixture.

The nickel oxide ore as the raw material ore is not particularly limited, and may be limonite ore, saprolite ore, etc. Nickel oxide ore contains nickel oxide (NiO) and iron oxide (Fe ₂ O ₃ ) as constituents.

As described above, in the mixing process S1, a specific amount of carbonaceous reducing agent is added to the nickel oxide ore and mixed to form a mixture. The carbonaceous reducing agent is not particularly limited, but examples include coal powder and coke powder. It is preferable that the carbonaceous reducing agent has the same particle size as the nickel oxide ore, which is the raw material ore. If the particle sizes of the carbonaceous reducing agent and the nickel oxide ore are the same, they can be easily mixed uniformly, and as a result, the reduction reaction can occur uniformly, which is preferable.

The amount of the carbonaceous reducing agent is not particularly limited, but is preferably 50.0% or less, and more preferably 40.0% or less, when the amount of the carbonaceous reducing agent required to reduce the nickel oxide and iron oxide constituting the nickel oxide ore without excess or deficiency is taken as 100%. Here, the amount of the carbonaceous reducing agent required to reduce the nickel oxide and iron oxide without excess or deficiency can be rephrased as the total value of the chemical equivalent required to reduce the entire amount of nickel oxide to nickel metal and the chemical equivalent required to reduce the iron oxide to iron metal (hereinafter also referred to as the "total value of chemical equivalents"). In this way, by setting the amount of the carbonaceous reducing agent to a ratio of 50.0% or less when the total value of the chemical equivalents is taken as 100%, the reduction reaction can be efficiently promoted. The lower limit of the amount of the carbonaceous reducing agent is not particularly limited, but is preferably 10.0% or more, and more preferably 15.0% or more, when the total value of the chemical equivalents is taken as 100%.

In addition to nickel oxide ore and carbonaceous reducing agent, the iron ore added as an optional component is not particularly limited, but examples include iron ore with an iron content of about 50% or more, and hematite obtained by wet smelting of nickel oxide ore. Examples of binders include bentonite, polysaccharides, resins, water glass, and dehydrated cake. Examples of flux components include calcium oxide, calcium hydroxide, calcium carbonate, and silicon dioxide.

Table 1 below shows an example of the composition (weight %) of some of the raw material powders mixed in the mixing process S1. Note that the composition of the raw material powders is not limited to this.

[Mixture molding process]
The mixture forming step S2 is a step of forming the mixture obtained in the mixing treatment step S1. Specifically, the mixture obtained by mixing the raw material powders is formed into a lump of a certain size or more so that the mixture can be, for example, stacked and charged into a reduction furnace during the reduction treatment in the next reduction step S3.

The shape of the agglomerates (also called pellets) obtained by molding the mixture can be rectangular, cylindrical, spherical, etc. Such shapes make it easy to mold the mixture and reduce molding costs. Furthermore, these shapes are not complicated, so there are almost no defective products and the yield rate of molding is extremely high. Furthermore, rectangular, cylindrical, and spherical shapes make it easy to stack them in the reduction furnace, making it possible to increase the amount of material to be processed during reduction. Furthermore, the amount of material to be processed during reduction can be increased without making each pellet huge, and they are easy to handle. In addition, they do not collapse when loaded into the reduction furnace, making it less likely to cause defects.

The volume of the pellets of the molded (agglomerated) mixture is not particularly limited, and can be, for example, 8000 ^mm3 or more. If the volume of the pellets is too small, the molding cost will be high, and it may be troublesome to charge the pellets into a reduction furnace. Furthermore, if the volume of the pellets is small, the ratio of the surface area to the entire pellet will be high, so that the difference in reduction between the surface and the inside is likely to appear, and this may affect the quality of ferronickel. By setting the volume of the pellets of the mixture to 8000 ^mm3 or more, molding costs can be suppressed and handling is easy, which is preferable. Furthermore, high quality ferronickel can be produced.

After the mixture is molded, it may be subjected to a drying process. Depending on the moisture in the mixture, the rapid temperature rise during the reduction process may cause the moisture in the mixture to evaporate and expand all at once, causing the mixture to break into pieces. For this reason, a drying process may be provided after the mixture molding process to dry the mixture. For example, in the drying process, a drying process may be performed so that the solid content of the mixture is about 70% by weight and the moisture content is about 30% by weight.

There are no particular limitations on the method of drying the mixture, and for example, hot air at 150°C to 400°C can be blown onto the lumps to dry them. If the mixture is in relatively large lumps, it is acceptable for the mixture to have cracks or fissures before and after drying. If the lumps are large, the effect is minimal even if the surface area increases due to cracks, etc.

Table 2 below shows an example of the composition (parts by weight) of the solid content in the mixture (after drying). Note that the composition of the mixture is not limited to this.

[Reduction process]
In the reduction step S3, the mixture (molded product) obtained in the mixture molding step S2 is reduced and heated to a predetermined reduction temperature in a reduction furnace. This reduction process causes a smelting reaction (reduction reaction) of the mixture containing nickel oxide ore to proceed, producing metal and slag.

The temperature of the reduction treatment (reduction temperature) is preferably 1200°C or higher and 1500°C or lower, and more preferably 1250°C or higher and 1450°C or lower. By setting the reduction temperature within this range, the reduction reaction can proceed efficiently and reliably, and ferronickel with the desired characteristics can be obtained.

During the reduction process, the slag in the mixture becomes semi-molten and the liquid and solid phases coexist, but the metal and slag that have already separated do not mix together, and subsequent cooling results in a mixture of metal solid and slag solid phases that coexist as separate phases. The volume of this mixture has shrunk to about 50% to 60% of the volume of the mixture being charged.

Now, in this embodiment, in the reduction step S3, a sample ladle having a handle and a sample placement part connected to the end of the handle is used, the mixture is placed on the sample placement part, and the reduction process is carried out while a cooling medium is flowed inside the handle.

First, we will explain the configuration of the reduction furnace used in the reduction process S3. Figure 2 is a schematic diagram showing an example of the configuration of the reduction furnace.

As shown in FIG. 2, the reduction furnace 1 can be a box furnace in which the furnace body 11 has a box shape (rectangular parallelepiped shape). The reduction furnace 1 can be a burner furnace in which a burner 12 is provided at a predetermined position and the reduction process is performed by heating with the burner, although this is not particularly limited. By adopting burner heating (burner furnace) as the heating method for the reduction furnace 1, the inside of the furnace can be heated with excellent combustibility, which is preferable. The fuel for the burner is not particularly limited and may be any of gas fuels such as LPG, liquid fuels such as heavy oil, and solid fuels such as coal and coke, but LPG is preferable because of its excellent combustibility.

The reduction furnace 1 also includes a sample stage 13 that is disposed inside the box-shaped furnace body 11 and in contact with a specific surface of the box (the inner surface of the furnace body 11). The sample stage 13 is a stage on which the mixture to be reduced is placed. A reducing agent such as a carbonaceous reducing agent may be laid on the upper surface of the sample stage 13.

The reduction furnace 1 also has an exhaust port 14, for example on its upper surface (ceiling surface), for exhausting gas from within the furnace.

A sample loading/unloading port 15 is provided on a specific side of the reduction furnace 1 for loading a sample mixture into the reduction furnace and for removing the reduced product obtained by reduction treatment from the reduction furnace. The height position of the sample loading/unloading port 15 corresponds approximately to the height of the mounting surface of the sample stage 13 inside the furnace body 11. Therefore, when a mixture is loaded from the sample loading/unloading port 15, it can be appropriately placed on the mounting surface of the sample stage 13. Furthermore, when removing the reduced product, it can be easily removed from the sample loading/unloading port 15, which is provided at the same height as the sample stage 13.

Although not shown, the sample loading/unloading port 15 is provided with an opening/closing door, which can be opened when loading the mixture or unloading the reduced product, and closed when performing the reduction process. This allows the inside of the reduction furnace 1 to be an airtight space during the reduction process.

Next, the sample ladle will be described. As described above, in this embodiment, a sample ladle is used to load the mixture into the reduction furnace 1 and to remove the reduced product from the reduction furnace 1. The mixture is placed on the sample placement section of the sample ladle, and the reduction process is carried out while a cooling medium is flowed inside the handle.

Figure 3 shows an example of the configuration of a sample ladle. As shown in Figure 3, the sample ladle 2 has a handle 21 and a sample placement part 22 connected to the tip of the handle 21.

In the sample ladle 2, the handle 21 is the part that the operator holds by hand or machine, and is composed of a rod-shaped body. The sample placement part 22 is connected to the tip of the handle 21, and is the part on whose upper surface (placement surface 22a) the sample, i.e., the mixture to be subjected to reduction treatment, is placed. Note that, although FIG. 3 shows an example in which the sample placement part 22 is composed of a rectangular parallelepiped, this is not limiting, and for example, the placement surface for the mixture, which is the sample, forms a recess, and the sample may be composed of something like a container with walls erected on all four sides and an open top.

In the sample ladle 2, the inside of the handle 21 is hollow, and a cooling medium flows through it. By configuring the handle 21 in this way so that a cooling medium flows through it, the handle 21 can be cooled effectively, and deformation due to high temperatures in the reduction furnace 1 can be prevented.

Specifically, in the sample ladle 2, for example, a cooling medium supply hose is connected to the end of the handle 21 (cooling medium supply port 21a), and the cooling medium flows into the inside of the handle 21 as shown by the arrow X in Figure 3. The cooling medium flows inside the handle 21 in the direction in which the sample mounting part 22 is connected, and is then discharged (arrow Y in Figure 3) from the cooling medium discharge port 21b provided between the connection point with the sample mounting part 22.

The cooling medium is not particularly limited, and various media can be used, such as liquids such as water, and gases such as air and inert gases. However, when discharging the cooling medium to the outside of the sample ladle 2, it is undesirable to release media such as gases containing moisture or oxygen into the reduction furnace 1, which is a reducing atmosphere. From this point of view, it is particularly preferable to use inert gases such as nitrogen gas and argon gas as the cooling medium.

In addition, if the handle 21 of the sample ladle 2 is structured as a double tube with a double cross section, so that the circulating cooling medium is discharged outside the reduction furnace 1 without being discharged into the reduction furnace 1, a liquid such as water or a gas containing oxygen may be used as the cooling medium.

To explain the operation of the reduction treatment in more detail, first, the sample mixture is placed on the sample placement part 22 of the sample ladle 2, and in this state, the handle 21 is grasped by an operator's hand or by a machine, the sample inlet/outlet port 15 of the reduction furnace 1 is opened, and the handle 21 of the sample ladle 2 is pushed in to insert the sample placement part 22 into the reduction furnace 1. Then, the sample ladle 2 placed in the reduction furnace 1 is moved to near the center of the sample stage 13, and the sample ladle 2 itself is placed on the sample stage 13, and the reduction treatment is started in this state (with the mixture placed on the sample ladle 2). In other words, during the reduction treatment, heating is started while the sample ladle 2 is left in the reduction furnace 1.

The reduction process is performed while circulating a cooling medium inside the handle 21 of the sample ladle 2. This effectively prevents problems such as thermal deformation of the handle 21, even if the reduction process is performed by heating the sample ladle 2 to a high temperature of, for example, 1200°C to 1500°C while it is still placed in the reduction furnace 1.

In addition, ash or a carbonaceous reducing agent may be laid on the sample placement portion 22 of the sample ladle 2. This can prevent the mixture from fusing on the placement surface of the sample placement portion 22.

After the reduction process in the reduction furnace 1 is completed, the reduced product obtained by the reduction process is removed from the sample loading/unloading port 15. As described above, in this embodiment, the sample ladle 2 is used, the mixture is placed on its sample placement section 22, and the reduction process is performed while a cooling medium is flowing inside the handle 21, so that thermal deformation of the handle 21 due to the high reduction temperature can be effectively prevented. As a result, even when removing the reduced product from the reduction furnace 1 by removing the sample ladle 2, operational problems such as the product getting caught on the inner wall of the furnace and becoming impossible to remove can be prevented, and it becomes possible to remove the reduced product in a short period of time. Furthermore, by improving workability and shortening the work time in this way, deterioration in the quality of the reduced product generated can also be effectively suppressed.

By carrying out the reduction process in the reduction step S3 as described above, ferronickel can be produced accurately, reliably, and efficiently.

[Recovery process]
In the recovery step S4, the metal and slag produced in the reduction step S3 are separated and the metal is recovered. Specifically, the metal phase is separated and recovered from a mixture (mixture) containing a metal phase (metal solid phase) and a slag phase (slag solid phase) obtained by subjecting the mixture filled in a container to a reduction heat treatment.

Methods for separating the metal phase and the slag phase from the mixture of metal phase and slag phase obtained as a solid include, for example, removing unnecessary materials by sieving, as well as separation by specific gravity or by magnetic force.

The obtained metal phase and slag phase can be easily separated due to their poor wettability. For example, by dropping the large mixture obtained by the treatment in the reduction step S3 described above over a predetermined drop or by applying a certain amount of vibration during sieving, the metal phase and slag phase can be easily separated from the mixture.

In this way, the metal phase and the slag phase are separated, and the metal phase, i.e., ferronickel, is recovered.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[Examples and Comparative Examples]
A method for smelting nickel oxide ore was carried out to produce ferronickel by reducing a mixture of nickel oxide ore, which is a raw material ore, and a carbonaceous reductant under the conditions shown below.

(Mixing process)
A mixture was obtained by mixing nickel oxide ore as raw ore, iron ore, silica sand and limestone as flux components, a binder, and a carbonaceous reducing agent (coal powder, carbon content: 79% by weight, average particle size: about 82 μm) using a mixer while adding an appropriate amount of water. The carbonaceous reducing agent was contained in an amount that was 36.0% when the amount required to reduce nickel oxide and iron oxide (Fe ₂ O ₃ ) contained in the nickel oxide ore as raw ore was taken as 100%.

(Mixture molding process)
The resulting mixture was then granulated using a pan-type granulator and sieved to a size of φ15.0±0.5 mm. Thereafter, the sample was dried by blowing hot air at 170°C to 250°C onto it before reduction so that the solid content was about 70% by weight and the moisture content was about 30% by weight. The solid content composition (excluding carbon) of the sample after drying is shown in Table 3 below.

(Reduction process)
Next, the sieved sample (mixture sample) was divided into 12 pieces (Examples 1 to 9, Comparative Examples 1 to 3), and each was heated in a reduction furnace (burner furnace) to undergo reduction treatment.

In this embodiment, a box-shaped burner furnace as shown in the schematic diagram of Fig. 2 was used as the reduction furnace. Pulverized coal, LPG, heavy oil, and coke were used as burner fuel for the reduction furnace. A sample ladle with a handle and a sample mounting part at the tip of the handle as shown in the schematic diagram of Fig. 3 was used, and the mixture sample was placed on the sample mounting part, and reduction treatment was performed while flowing nitrogen gas as a cooling medium inside the handle. Ash (mainly _SiO2 , containing small amounts of oxides such as _Al2O3 and MgO as other components) was spread on the upper surface of the sample mounting part, _and the mixture sample was placed on top of it.

When loading the mixture into the reduction furnace, the lid of the sample inlet/outlet of the reduction furnace was opened, and the sample ladle with the mixture sample placed on it was placed on the sample stage inside the reduction furnace. Then, with the sample ladle still placed on the sample stage, the lid of the sample inlet/outlet was closed to make the reduction furnace an airtight space, and heating with a burner was started to carry out the reduction process. After the specified reduction time had elapsed, the sample ladle with the mixture (reduced product) placed on it was removed from the reduction furnace.

After the extracted reduced material was cooled, the nickel metallization rate and nickel content in the metal were measured, as shown below.

In the comparative example, a sample ladle similar to that used in the example was used, but the reduction process was carried out without circulating a cooling medium through the handle.

[evaluation]
After cooling each sample, the nickel metallization rate and the nickel content in the metal, defined by the following formula, were analyzed and calculated using an ICP emission spectrometer (SHIMAZU S-8100).
Nickel metal ratio = amount of metalized Ni in the mixture ÷ (total amount of Ni in the mixture) × 100 (%) ... [1] Metal nickel content = amount of metalized Ni in the mixture ÷ (total amount of metalized Ni and Fe in the mixture) × 100 (%) ... [2]

The removal of the reduced material from the reduction furnace was also evaluated. In other words, the evaluation was performed as follows: if the removal could be performed without any problems, it was marked as "○", if it took more than 30 seconds because the sample ladle became deformed and got caught on the inner wall of the furnace, it was marked as "△", and if the sample ladle became deformed and got caught on the inner wall of the furnace, it was marked as "×".

Table 4 below shows the reduction treatment conditions and the calculation results for the nickel metal ratio and nickel content in the metal.

As shown in Table 4, in Examples 1 to 11, both the nickel metallization rate and the metal content were good. This is thought to be because the reduction process was carried out while a cooling medium was flowing inside the handle of the sample ladle, which effectively prevented the handle from being thermally deformed, and in particular allowed the work of removing the reduced product to be carried out smoothly.

On the other hand, in Comparative Example 1, in which the reduction process was carried out without flowing a cooling medium inside the handle of the sample ladle, the handle of the sample ladle became deformed by heat, and when the reduced material was removed, it got caught on the inner wall of the furnace, which required a lot of work. In Comparative Examples 2 and 3, the handle was so deformed that the reduced material could not be removed.

REFERENCE SIGNS LIST 1 reduction furnace 11 furnace body 12 burner 13 sample stage 14 exhaust port 15 sample loading/unloading port 2 sample ladle 21 handle 22 sample placement portion

Claims (3)

A method for smelting nickel oxide ore to produce ferronickel by reducing a mixture containing nickel oxide ore as a raw material ore and a carbonaceous reductant, comprising the steps of:
a mixing step of mixing the nickel oxide ore with the carbonaceous reductant;
a reduction step of charging the mixture into a reduction furnace and heating the mixture to subject it to a reduction treatment;
having
In the reduction step,
using a sample ladle having a handle and a sample placement part connected to the tip of the handle, placing the mixture on the sample placement part, and carrying out a reduction treatment while flowing a cooling medium inside the handle;
A method for smelting nickel oxide ores. Flowing an inert gas as the cooling medium into the inside of the handle;
2. The method for smelting nickel oxide ore according to claim 1. In the reduction step,
In the reduction furnace, a reduction treatment is performed at a reduction temperature of 1200° C. or more and 1500° C. or less.
3. A method for smelting nickel oxide ore according to claim 1 or 2.

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