JP2013019004A - Method of concentrating nickel for nickel oxide ore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of concentrating nickel for effectively and efficiently concentrating nickel in low-nickel-grade nickel oxide ore, recovering nickel at a high recovery rate, and enabling use of the nickel as a raw material for ferronickel smelting.SOLUTION: The method includes: a sieving step S1 of sieving the nickel oxide ore using a sieve with a predetermined aperture; a drying step S2 of drying the nickel oxide ore on the sieve; a crushing and sieving step S3 of crushing the dried nickel oxide and sieving the nickel oxide ore using a sieve with an aperture smaller than that of the sieve used at the sieving step S1; and a recovering step S4 of recovering the nickel oxide ore having passed through the sieve at the sieving step S1 and the nickel oxide ore having passed through the sieve at the crushing and sieving step S3 as a nickel concentrate, wherein the nickel oxide ore is crushed at the crushing and sieving step S3 such that a weight ratio of the crushed product is 40-85%.

Description

  The present invention relates to a nickel concentration method for nickel oxide ore, and more particularly to a nickel concentration method for nickel oxide ore in which nickel contained in saprolite ore is concentrated as nickel oxide ore.

  Nickel minerals used as raw materials for smelting nickel can be broadly classified into nickel sulfide ores and nickel oxide ores such as garnierite ore and laterite ore.

  Ferronickel, which is a raw material for producing stainless steel, is produced using nickel oxide ore. Specifically, nickel oxide ore is dried and roasted at about 900 ° C., and the obtained sinter is put into a melting furnace such as an electric furnace to obtain ferronickel by reduction melting at a temperature of about 1500 ° C. Can do.

  However, such a method for producing ferronickel has a problem that costs are increased. In other words, nickel contained in nickel oxide ore (hereinafter also simply referred to as “oxide ore”) is finely distributed in viscous minerals such as serpentine and goethite, and the water content in the ore On the other hand, the nickel quality in the oxide ore is as low as about 2 to 2.6% by mass. For this reason, the energy required for drying the oxide ore and the amount of material to be processed per nickel amount increase.

  In addition, a decrease in the content of nickel in the oxide ore also leads to a decrease in nickel quality in the obtained ferronickel, and there is a concern of affecting the cost when smelting stainless steel. In general, the nickel lower grade in oxide ore is 2% by weight or more, which is a profitable lower limit. However, in recent years, nickel oxide ore with high nickel quality has been depleted, and the nickel quality of raw ore that can be used for ferronickel smelting has also been decreasing. Therefore, an increase in cost required for smelting and a decrease in productivity have become issues.

  Recently, as a method for efficiently recovering nickel from low nickel grade oxide ore, a method in which the oxide ore is put together with sulfuric acid in a pressure vessel and nickel and cobalt are leached under high temperature and pressure has been carried out. However, this high-temperature and high-pressure hydrometallurgical process consumes a large amount of sulfuric acid and is not suitable for saprolite ores with high magnesium quality.

  Therefore, it is required to improve the nickel quality of such oxide ores, particularly saprolite ores.

  Specifically, as disclosed in Non-Patent Document 1 or 2, for example, attempts have been made to increase nickel quality by applying a beneficiation method such as flotation or magnetic separation. However, these methods have many problems in that the results vary depending on the ore, and stable operation is difficult, and the processing cost is increased.

  Further, as disclosed in, for example, Patent Document 1, the oxide ore is roasted at 950 to 1200 ° C. together with a halogen compound and a solid reducing agent to produce an iron alloy containing nickel. A method for concentrating nickel has also been proposed. However, this method requires energy for roasting and increases the cost.

  On the other hand, as disclosed in Patent Documents 2 to 5, for example, the saprolite ore of the raw material is classified without performing roasting at a high temperature, and further, the specific gravity selection is performed for each classification division, whereby nickel quality is achieved. A method of raising the value has been proposed.

  However, since the methods described in Patent Documents 2 to 5 are wet methods, oxide ores such as saprolite ore are not preferable in terms of sedimentation and dewaterability from the slurry. And a dehydrator is required. In this regard, Patent Document 6 proposes a method of adding an organic flocculant and concentrating ore mud in order to improve the sedimentation property of saprolite ore. However, a large amount of flocculant is used. It becomes necessary and is not efficient. In addition, these methods of Patent Documents 2 to 6 require a lot of labor for wastewater treatment and tailing management, which increases the capital investment and costs, and because it is a wet method, there is also a burden on the environment. Become very large.

  On the other hand, as disclosed in Patent Document 7, for example, a method of recovering the ground ore as a nickel concentrate by grinding the surface layer of nickel oxide ore has been proposed. However, in this method, since the surface layer portion having a high nickel quality is recovered from the nickel oxide ore, the nickel recovery rate is low even if the nickel can be concentrated. For this reason, for example, the amount of nickel that can be recovered is reduced with respect to the transportation cost of the oxide ore and the energy cost required for the concentration treatment, which is very inefficient.

  As described above, these conventional technologies effectively concentrate nickel of nickel oxide ore with low nickel quality, such as saprolite ore, while effectively reducing costs and environmental burden, and at a high recovery rate. It was not easy to recover economically as a ferronickel smelting raw material.

JP-A 64-005094 US Pat. No. 6,053,327 Japanese Patent Laid-Open No. 52-023504 Japanese Patent Publication No. 03-004610 JP 11-1117030 A JP-A-11-124640 JP 2009-138260 A

"Abstracts of Lectures of the Japan Mining Association Research Results Presentation", 1987, p. 365-366 “CIM Bullet” (Canada), Vol. 93, No. 1038, 2000, p. 37-43

  Therefore, the present invention has been proposed in view of such circumstances, and can effectively and efficiently concentrate nickel of nickel oxide ore with low nickel quality and recover nickel at a high recovery rate. For example, an object of the present invention is to provide a nickel enrichment method for nickel oxide ore that can be efficiently and efficiently used as a raw material for ferronickel smelting.

  As a result of intensive investigations to achieve the above-mentioned object, the present inventors have found that weathered ore has a high nickel quality and that weathered ore becomes brittle due to dissolution of the contained components. It is found that nickel-enriched oxide ore can be recovered effectively and efficiently by pulverizing and sieving under specified conditions using the difference in hardness of the ore. The present invention has been completed.

  That is, the nickel concentration method for nickel oxide ore according to the present invention includes a sieving step of sieving the oxide ore containing nickel with a sieve having a predetermined opening, and a sieve that has not passed through the sieving in the sieving step. The drying step for drying the above oxide ore, and the dried ore obtained by pulverization, and the pulverized oxide ore with a sieve having a size smaller than the opening of the sieve used in the above sieving step A sieving and sieving step, and a recovery step of recovering the oxidized ore under the sieve in the sieving step and the oxidized ore under the sieving in the sieving and sieving step as a nickel concentrate, In the sieving step, the oxidized ore is pulverized such that the weight ratio of the pulverized product under the sieve is 40% or more and 85% or less with respect to the weight of the oxidized ore before pulverization.

  According to the present invention, nickel of nickel oxide ore such as saprolite ore having low nickel quality can be effectively and efficiently concentrated, and nickel can be recovered at a high recovery rate.

  In addition, by being able to efficiently concentrate nickel contained in oxide ore, it is possible to increase the amount of nickel oxide ore resources that are being depleted, and further reduce transportation costs and energy costs required for smelting, For example, it can be effectively used as a raw material for ferronickel smelting. Furthermore, treatments such as dehydration and wastewater treatment are not required, and the burden on the environment is extremely small.

It is process drawing of the nickel concentration method of the nickel oxide ore which concerns on this Embodiment. It is a figure which shows the relationship of the raise width | variety of the nickel quality under a sieve with respect to the weight ratio of a sieved ground product. It is a figure which shows the relationship of the nickel recovery rate under a sieve with respect to the weight ratio of a sieved ground product.

  Hereinafter, a specific embodiment (hereinafter referred to as this embodiment) of a nickel concentration method of nickel oxide ore according to the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.

  In the nickel concentration method of nickel oxide ore according to the present embodiment (hereinafter also referred to as nickel concentration method), the weathered nickel oxide ore is nickel-enriched and has high nickel quality, and is brittle and easily pulverized. It uses the property, and is characterized by pulverizing and sieving under predetermined conditions. According to this nickel concentration method, it is possible to effectively concentrate nickel contained in low-quality nickel oxide ore and to recover nickel at a high recovery rate. For example, a raw material for ferronickel smelting It can be used as economically and efficiently.

  In particular, it can be suitably used for saprolite ores that are produced from laterite deposits, become raw ores of ferronickel, and have recently been depleted of high nickel grade ores. The saprolite ore is an ore that contains magnesia, silica, iron, and the like as main components, and is composed of minerals such as hydrous silicic earth mineral and goethite.

  Specifically, in the nickel concentration method according to the present embodiment, as shown in FIG. 1, in the sieving step S1 and the sieving step S1, the oxide ore containing nickel is sieved with a sieve having a predetermined opening. Drying step S2 for drying the oxidized ore on the sieve that did not pass through the sieve, and pulverizing the oxidized ore obtained by drying, and using the pulverized oxidized ore in the sieving step S1 Recovering the sieving and sieving step S3 with a sieve having a size of the opening, and collecting the ore under the sieve in the sieving step S1 and the oxidized ore under the sieving step S3 as a nickel concentrate Step S4. In this nickel concentration method, in the pulverization and sieving step S3, the oxidized ore is pulverized so that the weight ratio of the pulverized product under the sieve is about 40% to 85% with respect to the weight of the oxidized ore before pulverization. To do.

(Sieving process)
In the sieving step S1, the oxidized ore containing nickel is sieved with a sieve having a predetermined opening. Nickel contained in the oxide ore has the property of being easily concentrated to fine ore among the ores. Therefore, when sieving with a sieve having a predetermined opening in the sieving step S1, the oxidized ore below the sieve passes through the ferronickel as an oxidized ore in which nickel is concentrated without being processed in each step described later. It can be used as a raw material for smelting.

  Here, the mesh opening of the sieve is preferably set in a range in which the nickel quality does not deteriorate too much. Since the distribution state of nickel contained in the oxide ore varies depending on the mine and ore deposit, for example, a preliminary test can be performed to investigate the distribution state of nickel according to the particle size, and the sieve opening can be set.

  Specifically, the sieve opening is preferably 5 mm or more and 450 mm or less. When the sieve opening is less than 5 mm, the spread is too fine, and the sieve is clogged with clay contained in the oxidized ore. In particular, saprolite ore and the like have a high water content of 30% by mass or more, so that the influence of clogging is increased. In addition, there is a high possibility that fine oxide ore that has passed through the sieve will be scattered, resulting in poor handling and a loss of recovery. On the other hand, if the spread of the sieve is larger than 450 mm, the nickel quality may be lowered too much, and the transportation of the oxidized ore obtained through the sieve becomes difficult and the cost becomes high, It becomes inefficient.

  More preferably, the sieve has an opening of 10 mm or more and 200 mm or less. By setting the sieve opening to 10 mm or more and 200 mm or less, sieving can be performed more effectively without causing clogging or deterioration of handling properties, and without lowering the nickel quality of the oxidized ore passing through the sieve. It can be carried out.

  The sieving method is not particularly limited, and for example, a general grizzly or vibration sieve can be used.

  In addition, when the oxide ore containing nickel for sieving is too large or in a lump shape and cannot be supplied as it is to the sieving process in the sieving step S1, a hammer mill, a jaw crusher, etc. A general crusher may be used to crush the oxidized ore into an appropriate particle size to improve handling properties.

  Thus, when sieving of the oxidized ore is performed using a sieve having a predetermined mesh size in the sieving step S1, the sieving (or under the net) oxide ore that has passed through the sieve is fine-grained as described above. Therefore, it is recovered in the recovery step S4 as it is and becomes a concentrate as a nickel-enriched ore. On the other hand, the oxidized ore remaining on the sieve (on the net) without passing through the sieve is an oxidized ore in which nickel is not concentrated, and this oxidized ore is supplied to the subsequent drying step S2.

(Drying process)
In the drying step S2, the oxidized ore on the sieve that has not passed through the sieve in the sieving step S1 is dried. As described above, oxide ores such as saprolite ore originally have a water content of 30% by mass or more, and clay and fine particles are likely to adhere. Therefore, by drying the oxide ore on the sieve in the drying step S2, the clay and fine particles adhering to the coarse ore in the next step can be easily peeled off, and the pulverization can be efficiently performed.

  Moreover, by performing the drying process on the oxidized ore on the sieve after the sieving step S1 instead of before the sieving step S1, the oxidized ore can be efficiently dried with lower energy. That is, in the oxide ore such as saprolite ore, the finer one has a higher water content and the coarser one has a lower water content. Therefore, the amount of moisture in the oxidized ore remaining on the sieve is relatively lower than that of the fine-grained oxidized ore that has passed through the sieve having a predetermined opening in the sieving step S1. Therefore, it can dry efficiently with low energy by performing a drying process with respect to the oxide ore on the sieve after sieving process S1 mentioned above.

  Although it is possible to remove deposits adhering to the oxide ore by washing with water, it takes a lot of time and requires a large amount of water, which is not preferable.

  Although it does not specifically limit as a drying method, It is preferable to carry out by air drying from a viewpoint that a special apparatus and energy are not required. In addition, a general hot air dryer, a heat dryer, etc. can be used as needed.

  Moreover, although drying time is not specifically limited, It is preferable to carry out until the dry weight of an oxide ore becomes constant. Moreover, what is necessary is just to set suitably the temperature which dry weight becomes constant as a preset drying temperature at the time of using a predetermined dryer suitably.

(Crushing and sieving process)
Next, in the pulverization and sieving step S3, the oxidized ore obtained through the drying process in the drying step S2 is pulverized, and the pulverized oxidized ore is sieved. At this time, in the nickel concentration method according to the present embodiment, the weight ratio of the pulverized product under the sieve that passed through the sieve in sieving after pulverization is about 40% or more and 85% or less with respect to the weight of the oxidized ore before pulverization. It is important to grind so that

  Nickel contained in the oxide ore has a property that it is contained in a large amount of weathered oxide ore. Further, weathered oxide ore has a property of being brittle and having a lower hardness than non-weathered oxide ore since the contained components have melted out. Therefore, when oxide ore is pulverized, weathered oxide ore rich in nickel is preferentially pulverized because it is relatively brittle, while mother rocks with low nickel quality are not pulverized because they are relatively hard. Will remain as an unground product.

  Therefore, in the nickel concentration method according to the present embodiment, using these properties, the oxidized ore after drying is pulverized under predetermined conditions, and the pulverized oxidized ore is sieved. Then, nickel ore weathered oxide ore is preferentially crushed and passes through the sieve, and nickel ore oxide ore is not crushed and therefore remains on the sieve without passing through the sieve. This makes it possible to fractionate oxidized ore with high nickel quality.

  Here, in FIG. 2, for example, four kinds of oxide ores (A to D) containing nickel are dried, and the dried oxide ore is placed in a rod mill having a diameter of 202 mm and a depth of 230 mm for 2 minutes, 5 minutes, and 10 minutes. The relationship of the increase in the nickel quality under the sieve with respect to the weight ratio of the sieved pulverized product when sieving with a sieve having a spread of 9.5 mm after pulverization for 20 minutes is shown. FIG. 3 shows the relationship of the nickel recovery rate under the sieve with respect to the weight ratio of the sieved ground product in the sieving after the grinding treatment.

  In addition, the increase width of the nickel quality in FIG. 2 is the increase width of the nickel quality of the pulverized product with respect to the nickel quality of the oxide ore before pulverization and sieving. Further, the nickel recovery rate in FIG. 3 is the actual yield of nickel in the pulverized product relative to the total amount of nickel contained in the oxidized ore before pulverization and sieving. Moreover, the plot in the graph of each oxide ore of A to D shown in FIG. 2 and FIG. 3 is a plot when pulverized from the left for 2 minutes, 5 minutes, 10 minutes, and 20 minutes.

  As shown in FIG. 2, in each oxide ore, it can be seen that the crushed product with a shorter pulverization time and smaller weight ratio has a higher nickel quality increase rate, that is, a nickel concentration rate. This is presumably due to the fact that weathered oxide ore with high nickel quality is preferentially crushed, so that most of the pulverized products under the sieve are weathered oxide ore. On the other hand, however, these pulverized products under a sieve having a small weight ratio have a low nickel recovery rate and a large nickel content that causes a recovery loss, as shown in FIG. This is because the oxide ore, which is an unground product remaining on the sieve, still contains nickel, and the actual yield relative to the total amount of nickel contained in the oxide ore is low.

  On the other hand, when the pulverization time is increased and most of the oxide ore is pulverized and the weight ratio under the sieve increases, the nickel recovery rate naturally increases as shown in FIG. 3, but as shown in FIG. It can be seen that the increase in nickel quality of the crushed product under the sieve is low. As the pulverization time becomes longer, even the mother rock having a low nickel quality is pulverized and transferred to a sieve to become a pulverized product, which is very low from the viewpoint of the nickel concentration rate.

  From this, in the nickel concentration method according to the present embodiment, pulverization is performed so that the weight ratio of the pulverized product under the sieve that has passed through the sieve is about 40% or more and 85% or less. As a result, nickel contained in the oxide ore can be effectively concentrated, and the oxide ore can be collected separately so as to achieve a high recovery rate from the viewpoint of the nickel recovery rate. As described above, when the weight ratio of the pulverized product under the sieve is less than 40%, even the weathered oxide ore containing a large amount of nickel remains as an unground product, and the nickel recovery rate decreases. . On the other hand, when the weight ratio of the pulverized product under the sieve is larger than 85%, the nickel content of the pulverized product under the sieve is deteriorated even if the nickel content is low.

  The method for pulverizing the oxide ore is not particularly limited, and it can be pulverized by using a general pulverizer such as a ball mill, a rod mill, or an AG mill. The size of the pulverizer, the size of the pulverizing medium, and the like may be selected as appropriate by conducting a preliminary test on the distribution of the particle size, hardness, etc. of the oxide ore to be pulverized.

  The pulverization time is not particularly limited, and is adjusted as appropriate based on the pulverization strength and pulverization efficiency of the pulverizer to be used, the hardness of the ore, and the like. What is necessary is just to set so that it may be 40% or more and 85% or less. In addition, since the distribution of hardness of the oxide ore varies depending on the production area and properties of the ore, for example, a preliminary test on the oxide ore as described above is performed, and the weight of the pulverized product under the sieve is based on the result of the preliminary test. You may set so that a ratio may be about 40% or more and 85% or less.

  The other pulverization conditions are not limited to the conditions in FIGS. 2 and 3 described above, so that the weight ratio of the pulverized product passing through the sieve is about 40% or more and 85% or less. By pulverizing, the nickel contained in the oxide ore can be effectively concentrated, and the oxide ore can be collected separately so as to obtain a high recovery rate from the viewpoint of the nickel recovery rate.

  In the sieving process after pulverization, the mesh size of the sieve is set to a size equal to or smaller than the mesh size of the sieve used in the sieving step S1 described above. Thereby, like the sieving in the sieving step S1, the pulverized product can be sieved within a range where the nickel quality does not deteriorate too much, and the nickel-enriched ore can be recovered. The sieve opening used is more preferably at least half the size of the sieve opening used in the sieving step S1. Thereby, it is possible to recover a good oxide ore enriched with nickel without causing clogging or the like.

  Moreover, it does not specifically limit as a sieving method, It can carry out by general grizzly, a vibration sieve, etc. similarly to the sieving in sieving process S1, for example.

(Recovery process)
And in collection | recovery process S4, the ore which passed the sieve by sieving in sieving process S1, and the ore which passed the sieve by sieving after the grinding | pulverization and sieving process S3 are collect | recovered as nickel concentrate.

  As described above, the ore that has passed through the sieve in the sieving step S1 is a fine-grained ore and is an ore that has already been enriched with nickel. Further, the ore that has passed through the sieve in the pulverization and sieving step S3 is also a selectively recovered ore that has been weathered and enriched with nickel as described above. Therefore, the ore that has passed through the sieve in the sieving step S1 and the pulverizing and sieving step S3 becomes a high nickel grade ore enriched with nickel, and is effective as a nickel-concentrated ore, for example, as a raw material for ferronickel smelting and the like. Can be used for

  On the other hand, the oxidized ore remaining on the sieve in the sieving process after pulverization in the pulverization and sieving step S3 is composed of a host rock having a low nickel quality and is discarded as waste stone.

  As described above, according to the nickel concentration method of the nickel oxide ore according to the present embodiment, the weathered nickel high-quality oxide ore is used in a predetermined manner by utilizing its brittle and easily pulverized property. Since sieving is performed by pulverizing under conditions, nickel contained in the oxide ore can be effectively concentrated, and recovery loss can be suppressed and nickel can be recovered at a high recovery rate.

  And since nickel can be concentrated effectively in this way, the amount of nickel oxide ore resources can be increased effectively, and transportation costs and energy costs required for smelting can be reduced.

  In addition, as described above, the nickel concentration method for nickel oxide ore according to the present embodiment can be suitably used for saprolite ore, which is an ore that has recently been depleted of high nickel grade ore. The amount of ore resources can be increased effectively. The saprolite ore is not particularly limited and can be applied to any nickel grade saprolite ore, but is particularly suitable for a very low nickel grade saprolite ore having a nickel grade of 2.3 mass% or less. Can be used.

  Furthermore, this nickel concentration method is not based on a conventional wet method that requires large equipment or a large amount of water, but is a method based on a dry process, so that the processing cost can be greatly reduced and the burden on the environment is extremely small. .

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. The nickel quality analysis in this example was performed by ICP emission analysis.

Example 1
Four types of saprolite ores (oxide ores) A to D collected from the mine were pulverized to 100 mm or less with a jaw crusher in order to improve handling properties. Next, the oxidized ore crushed to 100 mm or less was sieved using a grizzly having an opening of 19 mm (sieving step). The nickel grades of the saprolite ores A to D used were ore A of 1.74%, ore B of 0.95%, ore C of 1.29%, and ore D of 0.8. It was 61%.

  After sieving, the sieving oxide ore was separately collected as a nickel concentrate, and the sieving oxide ore was dried at 60 ° C. until a constant weight was obtained (drying step). In addition, drying was performed using the large sized constant temperature dryer (DRL823WA by Toyo Seisakusho Co., Ltd.).

  Next, the oxidized ore dried at 60 ° C. is put into a rod mill having a diameter of 202 mm and a depth of 230 mm, and pulverized for 2 minutes, 5 minutes, 10 minutes, and 20 minutes, respectively. Sieve using a grizzly with a mesh size (grinding and sieving step). Then, the pulverized product that passed through the sieve mesh was recovered as a nickel concentrate (recovery step), and the oxidized ore that did not pass through the sieve was discarded as an unground product.

  FIG. 2 and FIG. 3 show the increase in nickel quality and the nickel recovery rate with respect to the weight ratio of the pulverized product under the sieve obtained by pulverizing the nickel oxide ores A to D in this example at each pulverization time, respectively. It is a figure which shows a relationship.

  From the results shown in FIGS. 2 and 3, the weight ratio of the pulverized product under the sieve was able to be 40% or more and 85% or less by performing the pulverization treatment for 10 minutes in each sample (A to D). Table 1 specifically shows the nickel grade increase width, the nickel grade after concentration, and the nickel recovery rate for the pulverized product under the sieve after sieving after passing through the pulverization treatment for 10 minutes.

  As shown in Table 1, in the pulverized product obtained by pulverization so that the weight ratio of the pulverized product under the sieve is in the range of about 40% to 85%, the increase in nickel quality is 0.17% to It was 0.56%, and nickel could be effectively concentrated. The nickel recovery rate was 76.3% to 90.3%, indicating that nickel can be recovered from the oxide ore with a high recovery rate.

  Meanwhile, Table 2 shows the increase in nickel quality of the pulverized product, the nickel quality after concentration, and the nickel recovery rate when pulverized so that the weight ratio of the pulverized product under the sieve is 35%. The increase in nickel quality of the pulverized product, the nickel quality after concentration, and the nickel recovery rate when pulverized so that the weight ratio of the pulverized product under the sieve is 90%.

  As shown in Tables 2 and 3, when the weight ratio of the pulverized product under the sieve is 35% which is not in the range of about 40% to 85%, the increase in nickel quality is 0. Although nickel was effectively concentrated at 0.15% to 0.57%, the nickel recovery rate was very low, 38.9% to 56.0%, and the loss of nickel was increased. In addition, when pulverized so that the weight ratio of the pulverized product under the sieve is 90%, the nickel recovery rate was 95.6% to 98.2%. The range of increase was as extremely low as 0.10% to 0.12%, and nickel in the oxide ore could not be effectively concentrated.

Claims (5)

A sieving step of sieving the oxidized ore containing nickel with a sieve having a predetermined opening;
A drying step of drying the oxidized ore on the sieve that has not passed through the sieve in the sieving step;
Crushing the oxidized ore obtained by drying, and pulverizing and sieving the crushed oxide ore with a sieve having a mesh size less than or equal to that of the sieve used in the sieving step;
A recovery step of recovering the oxidized ore under the sieve in the sieving step and the oxidized ore under the sieving and sieving step as a nickel concentrate,
In the pulverization and sieving step, the oxidized ore is pulverized so that the weight ratio of the pulverized product under the sieve is 40% or more and 85% or less with respect to the weight of the oxidized ore before pulverization. A method for enriching nickel in ores.   The method for concentrating nickel oxide ore according to claim 1, wherein the sieve opening used in the sieving step is not less than 5 mm and not more than 450 mm.   3. The nickel concentration method for nickel oxide ore according to claim 1 or 2, wherein in the drying step, the oxide ore is air-dried.   The sieve opening used in the pulverizing and sieving step is at least half the size of the sieve opening used in the sieving step. A method for concentrating nickel of the nickel oxide ore according to Item.   5. The nickel concentration method for nickel oxide ore according to any one of claims 1 to 4, wherein the nickel-containing ore containing nickel is saprolite ore.

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