JP2022099597A - Production method of ore slurry, wet smelting method of nickel oxide ore - Google Patents

Abstract

To provide a method capable of obtaining ore slurry having an enhanced solid percentage content and slurry density without increasing an amount of a coagulant use in producing ore slurry containing a metallic ore such as a nickel oxide ore, etc. as a raw material.SOLUTION: A production method of ore slurry is configured to condense slurry containing a metallic ore to produce ore slurry to be used for reaction. In the method, at least two kinds of thickeners are used to thicken a prescribed ratio of the slurry, not including a total amount by two steps, and the same thickener is used in the second-stage thickening to slurry of a prescribed ratio having undergone a first-stage thickening and thickening to slurry of a balance.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing an ore slurry in which a slurry containing a metal ore is concentrated and subjected to a reaction, and a hydrometallurgical method for nickel oxide ore to which the method is applied.

In the field of nickel hydrometallurgy using nickel oxide ore (hereinafter, also simply referred to as “ore”) as a raw material, in recent years, high-pressure acid leaching (hereinafter referred to as “HPAL: High Pressure Acid Leach”” is used for acid leaching under high temperature and high pressure. The recovery of valuable metals from low-grade nickel oxide ore by the method) has been put into practical use. For the recovery of valuable metals such as nickel and cobalt leached from nickel oxide ore by the HPAL method, sulfides (sulfide) are added by adding a sulfide agent such as hydrogen sulfide gas to a sulfuric acid bath containing the valuable metals under pressure. A method of recovering as a mixed sulfide of nickel / cobalt) is generally performed.

In hydrometallurgy for recovering nickel-cobalt mixed sulfide, a nickel oxide ore slurry (hereinafter, also simply referred to as “ore slurry”) is sent to a high-pressure acid leaching step (hereinafter, simply referred to as “leaching step”). ) Is important to maximize the amount of nickel produced. Therefore, it is required to increase the slurry concentration in the ore slurry.

Therefore, conventionally, a thickener is used to perform a concentration treatment for increasing the solid component ratio of the ore slurry, and then the liquid is sent to the leaching step. As a result, the amount of nickel passed through the leaching step per unit time can be increased, and the amount of nickel produced can be increased.

However, since the sickening behavior differs depending on the ore type, the solid content of the ore slurry obtained from the thickener depends on the blended ore type, the blend ratio, the type of the flocculant used for sickening, the amount added, and the like. Therefore, until now, the ore slurry with the target solid component ratio has been adjusted by adjusting the type and amount of coagulant according to the blended ore type and blend ratio, referring to past data and the rules of thumb of workers. Was getting.

However, for example, when the ore type is changed, it becomes difficult to adjust the flocculant, and the solid content and density of the ore slurry may decrease or vary.

Japanese Unexamined Patent Publication No. 2015-08647

The present invention has been proposed in view of such circumstances, and in producing an ore slurry containing a metal ore such as nickel oxide ore as a raw material, the solid content rate without increasing the amount of a flocculant used or the like. And an object thereof is to provide a method capable of obtaining an ore slurry having an increased slurry density.

As a result of repeated diligent studies, the present inventor has found that the above-mentioned problems can be solved by the means shown below, and has completed the present invention.

(1) The first invention of the present invention is a method for producing an ore slurry in which a slurry containing a metal ore is concentrated to produce an ore slurry to be subjected to a reaction, and the slurry is prepared by using at least two thickeners. Of these, a predetermined ratio that does not include the entire amount is sickened in two stages, and the second stage sickening for the slurry of the predetermined ratio that has undergone the first stage sizing and the sizing for the slurry of the remaining ratio are performed. It is a method for producing an ore slurry, which is carried out by the same thickener.

(2) The second invention of the present invention is the method for producing an ore slurry in the first invention, wherein the ratio of the balance is more than 54% by mass and less than 78% by mass.

(3) The third aspect of the present invention is the method for producing an ore slurry in which the metal ore contains nickel oxide ore in the first or second invention.

(4) The fourth invention of the present invention is the method for producing an ore slurry in the third invention, wherein the ore particle size of the ore slurry is 1.7 mm or less.

(5) A fifth aspect of the present invention is the method for producing an ore slurry, wherein the ore slurry is subjected to an acid leaching treatment reaction in any one of the first to fourth inventions.

(6) The sixth invention of the present invention is a wet smelting method for nickel oxide ore, which is a slurry production step for producing a slurry of nickel oxide ore (ore slurry) and an acid is added to the ore slurry. In the slurry manufacturing step, a treatment for concentrating a slurry containing crushed nickel oxide ore is performed, and in the concentrating treatment, at least two thickeners are used to concentrate the slurry. Of these, a predetermined ratio that does not include the entire amount is sickened in two stages, and the second stage sickening for the slurry of the predetermined ratio that has undergone the first stage sizing and the sizing for the slurry of the remaining ratio are performed. It is a wet smelting method performed by the same thickener.

According to the present invention, when producing an ore slurry containing a metal ore as a raw material, it is possible to obtain an ore slurry having an increased solid content and slurry density without increasing the amount of a flocculant used or the like.

It is a figure which shows the structural example of the thickener equipment which performs the enrichment treatment with respect to the ore slurry, and is for explaining the operation of the enrichment treatment with respect to the ore slurry. As another aspect different from the thickener equipment shown in FIG. 1, a configuration example of the equipment provided with three thickeners is shown, and is a diagram for explaining an outline of the operation of the concentration treatment for the ore slurry. As another aspect different from the thickener equipment shown in FIG. 1, a configuration example of the equipment provided with four thickeners is shown, and is a diagram for explaining an outline of an operation of a concentration treatment for an ore slurry. The results in the examples are shown, and the slurry density obtained when the liquid feeding ratio to the second thickener is changed and the amount of the flocculant used in the first thickener and the second thickener with respect to 1 ton of ore are shown. It is a graph which shows the value and the increase / decrease ratio (%) with respect to each reference value.

Hereinafter, a specific embodiment of the present invention (hereinafter, also referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications without changing the gist of the present invention.

≪1. Outline of manufacturing method of ore slurry ≫
The method for producing an ore slurry according to the present embodiment is a method for producing an ore slurry to be subjected to a reaction by concentrating a slurry containing a metal ore.

Examples of the metal ore include nickel oxide ore, which can be preferably applied to a method for producing an ore slurry to be subjected to a reaction of high-pressure acid leaching treatment in a hydrometallurgical process of nickel oxide ore. The metal ore is not limited to the nickel oxide ore, and may be another metal ore, and can be applied to a treatment of slurrying and concentrating the ore for use in a reaction such as a leaching reaction.

Specifically, in the method for producing an ore slurry according to the present embodiment, a treatment of concentration by thickening using at least two coagulation sedimentation tanks (hereinafter referred to as "thickener") is performed. Then, a predetermined ratio of the slurry that does not contain the entire amount is thickened in two stages, and the second stage thickening for the predetermined ratio slurry that has undergone the first stage thickening and the remaining ratio slurry. It is characterized in that the slicking is performed by the same slicker.

Here, for example, in the wet smelting process of nickel oxide ore, the amount of nickel in the ore slurry supplied to the leaching step in which high-pressure acid leaching is performed can be obtained from the following formula.
Amount of nickel supplied to the leaching process (t / day)
= Total slurry supply amount (m ³ / day) x nickel grade (mass%) x slurry density (density: g / cm ³ ) x solid content (solid%: mass%)

Therefore, in order to increase and secure nickel production, it is important to increase and maintain the nickel grade, slurry density, and solid content in the slurry, which can be said to lead to stable and efficient production.

In this respect, according to the method for producing an ore slurry according to the present embodiment, the solid content and the slurry density in the ore slurry to be subjected to the reaction can be increased. As a result, when the ore slurry used for the reaction in the leaching step in the hydrometallurgical process of nickel oxide is taken as an example, the amount of nickel passing per unit time sent to the leaching step can be increased, and the nickel production amount can be increased. Can be enhanced.

In the following, with respect to the ore slurry to be produced, an ore slurry containing nickel oxide ore as a raw material as a metal ore will be taken as an example, and the production method thereof will be described more specifically. The ore slurry containing nickel oxide ore will be described as being subjected to a leaching step in which a high-pressure acid leaching reaction is carried out in a hydrometallurgical process.

≪2. About each process of the ore slurry manufacturing method ≫
The method for producing the ore slurry is divided into an ore classification step in which the raw material nickel oxide ore (hereinafter, also simply referred to as "ore") is crushed to a predetermined particle size and classified, and the ore classified to a target particle size or less. It includes a slurrying step of adding water to form a slurry and a slurry concentration step of concentrating a slurry containing ore.

[Ore classification process]
In the ore classification step, nickel oxide ore, which is a raw material ore, is crushed using a crusher, a crusher, etc., and the crushed ore is sieved and classified at a predetermined classification point to remove oversized ore particles. Later, you will only get undersized ore. For example, several types of nickel oxide ores are subjected to the same classification treatment and mixed so as to have a predetermined Ni grade and impurity grade.

Nickel oxide ores are mainly so-called laterite ores such as limonite ore and saprolite ore. The nickel content of the laterite ore is usually 0.8% by weight to 2.5% by weight, and is contained as a hydroxide or a siliceous earth (magnesium silicate) mineral. The iron content is 10% by mass to 50% by weight, mainly in the form of trivalent hydroxide (goethite), but some divalent iron is contained in the caustic mineral. ..

The classification method is not particularly limited as long as the ore can be classified based on the desired particle size. For example, it can be performed by sieving using a general vibrating sieve or the like.

The classification point is also not particularly limited, but the particle size of the ore contained in the ore slurry is preferably 1.7 mm or less, and more preferably 1.4 mm or less. Thereby, when the ore slurry produced through the steps described later is subjected to the treatment in the leaching step in the hydrometallurgical process of nickel oxide ore, nickel can be efficiently leached. Therefore, in the classification treatment, it is preferable to use a sieve having a sieve capable of classifying ore particles of 1.7 mm or less.

Therefore, in the classification treatment, it is preferable to use a sieve having a sieve capable of classifying ore particles of 1.7 mm or less. If the sieve mesh is too small, the yield in the processing in the ore classification process deteriorates, or the equipment such as the crusher and the sieve used in the processing in the ore classification process are strengthened, and the enhanced equipment is operated. And maintenance costs are newly required. Therefore, the lower limit of the sieve mesh is preferably 1.4 mm or more.

[Slurry process]
In the slurrying step, water is added to the ore particles having a predetermined particle size or less obtained by the ore classification step to obtain an ore slurry in the form of a slurry. The ore slurry obtained here is an ore slurry before the concentration treatment is performed in the next slurry concentration step, and is distinguished from the concentrated ore slurry used for the reaction in the leaching step as a "dilute ore slurry". Also called. The ore slurry obtained by performing the concentration treatment in the next slurry concentration step is also referred to as "concentrated ore slurry".

As the water added to the ore particles for slurrying, for example, industrial water can be used. Alternatively, the process water discharged in the hydrometallurgical process of nickel oxide ore may be used.

[Slurry concentration step]
In the slurry concentration step, the dilute ore slurry is subjected to a concentration treatment to increase the solid content and slurry density in the slurry to obtain an ore slurry (concentrated ore slurry). The solid content (solid%) of the dilute ore slurry, that is, the ore slurry to be subjected to the concentration treatment is not particularly limited, but is, for example, about 15% by mass to 20% by mass.

In the slurry concentration step, a process using a thickener (hereinafter, also referred to as “thickening”) is performed. FIG. 1 is a diagram showing a configuration example of a thickener facility that concentrates an ore slurry. The sickener equipment 1 shown in FIG. 1 shows an example in which two sickeners, a first sickener 11 and a second sickener 12, are provided, but the number is not limited to two.

The configuration of the thickener will be briefly described with reference to the second thickener 12 (hereinafter, also simply referred to as “sickner 12”). The thickener 12 includes a thickener main body 12a and a feed well 12b provided inside the thickener main body 12a. The thickener body 12a has a structure including a cylindrical outer frame and a conical bottom gradually lowered toward the center, and a rake is arranged along the inner surface of the conical bottom. In the thickener main body 12a, the slurry supplied from the feed well 12b is promoted by the rotation of the blades constituting the rake to promote the sedimentation and concentration of the slurry. In the thickener body 12a, a supernatant layer, a sedimentation layer, and a compression layer are formed in the slurry as the slurry is sedimented and concentrated. The feed well 12b is a supply unit that supplies the slurry to be sedimented and concentrated, and if necessary, a flocculant is added together with the slurry to be treated. In the thickener 12, a slurry having an increased solid content is generated by sedimentation and concentration of the slurry in the thickener main body 12a, and is taken out from an outlet provided at the bottom of the thickener main body 12a. In the thickener equipment 1 shown in FIG. 1, the specific structure of the first thickener 11 is not specified, but the structure is the same as that of the second thickener 12 described above, and a slurry having an increased solid content is generated. Let me.

In the method for producing an ore slurry according to the present embodiment, at least two thickeners are used, and a predetermined ratio of the dilute ore slurry, which does not contain the entire amount, is thickened in two steps. In other words, a two-step thickening using the first thickener 11 and the second thickener 12 is performed on a part of the diluted slurry, which is not all.

Specifically, in the example shown in FIG. 1, 31% by mass of the total amount (100% by mass) of the dilute ore slurry is sent to the first thickener 11, and the remaining 69% by mass of the slurry is sent to the second thickener. The liquid is sent to 12. In the first thickener 11, the dilute ore slurry having a liquid feed ratio of 31% by mass is thickened to generate a slurry having a solid content of, for example, 35% by mass to 40% by mass. That is, the first-stage sizing is performed on the dilute ore slurry in a proportion of 31% by mass of the total amount of the dilute ore slurry.

In the second thickener 12, a dilute ore slurry (slurry having a solid content of 15% by mass to 20% by mass) in a proportion of 69% by mass of the balance that was not sent to the first thickener 11 is sent and liquid is sent. The ore slurry (slurry having a solid content of 35% by mass to 40% by mass) obtained through the first-stage thickening in the first thickener 11 is sent and the thickening is performed. Therefore, for the dilute ore slurry in a proportion of 31% by mass of the total amount of the dilute ore slurry sent to the first thickener 11, the second-stage thickening is performed in the second thickener 12.

That is, the second-stage thickening for a predetermined ratio (31% by mass) of slurry that has undergone the first-stage thickening and the thickening for the remaining ratio (69% by mass) of slurry are the same thickener. This is done by the second thickener 12.

As described above, in the method for producing an ore slurry according to the present embodiment, in the concentration treatment for the dilute ore slurry, two or more thickeners provided in parallel are used, and a part of the dilute ore slurry is divided into two stages. Thicken with. Then, the slurry concentrated through the first-stage thickening and the remaining slurry not subjected to the first-stage thickening are combined and thickened with the same thickener (second thickener 12).

Here, for example, in Patent Document 1, a thickener facility in which a first thickener and a second thickener are provided in series is used, and the ore slurry is pre-concentrated with the first thickener to obtain an intermediate ore slurry, and then the first thickener is obtained. A method of concentrating an intermediate ore slurry with a second thickener, which has a higher sickening effect than a thickener, to obtain a concentrated ore slurry is disclosed. Such a method is an excellent method capable of producing an ore slurry having a high solid content and a high specific density while maintaining the slurry processing amount.

Further, in a facility equipped with such a plurality of thickeners, when the flow rate of the dilute ore slurry supplied to the first thickener is increased, a larger amount of slurry is concentrated by the first thickener, so that the second thickener is used. The load on the flow rate to the sill is reduced, and the slurry concentration can be improved by increasing the residence time in the second thickener.

However, on the other hand, if this operation is excessive, the amount of ore contained in the slurry supplied from the first thickener to the second thickener also increases, so that a higher concentration slurry is supplied to the second thickener. Then, in the second thickener, the clarity of the supernatant layer, which is an important factor in the operation of the thickener, may be impaired, resulting in an increase in the amount of the flocculant used in the thickener and a decrease in the sedimentation rate, and as a result, the second thickener is used. 2 It is conceivable that the slurry concentration obtained by the thickener will decrease.

Therefore, in the present embodiment, as described above, a facility in which at least two thickeners are provided in parallel is used, and only a part of the total amount of the dilute ore slurry, which is a predetermined ratio, is sickened in two stages. To slurry. In the equipment illustrated in FIG. 1, a part of the dilute ore slurry subjected to the two-step thickening is supplied to the first thickener 11 and then to the second thickener 12. That is, the thickening process is sequentially performed by the thickeners arranged in series. On the other hand, the dilute ore slurry having a residual ratio other than a part of the dilute ore slurry is supplied only to the second thickener 12 and subjected to the concentration treatment. That is, a part of the dilute ore slurry having a predetermined ratio and the rest of the dilute ore slurry are concentrated by the arrangement thickener in a parallel relationship.

According to such a method, it is possible to prevent an excessive amount of scully supplied to the first thickener 11 from being excessive, prevent the possibility that the clarity of the supernatant layer is impaired in the second thickener, and increase the amount of the flocculant used. It is possible to perform a good sedimentation concentration operation while suppressing a decrease in sedimentation rate.

Here, the predetermined ratio of the total amount of the dilute ore slurry to be supplied to the first thickener 11 to perform the two-step thickening is not particularly limited, but is 22% by mass or more when the total amount is 100% by mass. The ratio is preferably 46% by mass or less, and more preferably 28% by mass or more and 40% by mass or less.

Conversely, of the total amount of the dilute ore slurry, the ratio of the dilute ore slurry supplied to the second thickener 12 without performing the two-step thickening, that is, the ratio of the balance other than the above-mentioned predetermined ratio is 54 mass. It is preferably more than% and less than 78% by mass, and more preferably more than 60% by mass and less than 72% by mass. The ratio of the dilute ore slurry supplied to the second thickener 12 without performing the two-step thickening out of the total amount of the dilute ore slurry is synonymous with the liquid feeding ratio to the second thickener 12 in the examples described later. be.

By controlling the liquid feed at a ratio consisting of the above-mentioned ratio of the total amount of the dilute ore slurry, it is more preferable as shown in Examples described later, and the clarity is maintained while suppressing the amount of the flocculant used. , The sedimentation concentration process can be performed more effectively.

By the way, in the example of the sickener equipment and the processing operation shown in FIG. 1, the case where the equipment having the two sickeners of the first sickener 11 and the second sickener 12 is used has been described, but the sickener is limited to the two sickeners. is not.

For example, in the case of equipment using a total of three thickeners (referred to as “thickener equipment 2”), as shown in FIG. 2, a predetermined ratio (for example, 40% by mass) of the total amount of the dilute ore slurry. A part of the slurry, that is, the slurry performing two-step thickening, is supplied to the first thickener 21 and the second thickener 22 in equal amounts (for example, 20% by mass), respectively, and one step in each thickener. Eye concentration treatment is applied. Then, the slurry obtained through the treatment with the first thickener 21 and the slurry obtained through the treatment with the second thickener 22 are supplied to the third thickener 23 and are supplied to the third thickener 23. , The slurry of the balance (for example, 60% by mass) that was not supplied to the first thickener 21 and the second thickener 22 is supplied and concentrated.

Further, for example, in the case of equipment using a total of four thickeners (referred to as “thickener equipment 3”), as shown in FIG. 3, a part of the total amount of the dilute ore slurry is composed of a predetermined ratio. The slurry, that is, the slurry that performs two-step thickening, is supplied to the first thickener 31, the second thickener 32, and the third thickener 33, for example, in equal amounts, and each thickener is subjected to the first-stage concentration treatment. Will be done. Then, the slurry obtained through the treatment with the first thickener 31, the slurry obtained through the treatment with the second thickener 32, and the slurry obtained through the treatment with the third thickener 33 are the fourth thickener. Along with being supplied to 34, the fourth thickener 34 is supplied with a slurry having a portion of the balance that was not supplied to the first thickener 31, the second thickener 32, and the third thickener 33, and is subjected to a concentration treatment. ..

As mentioned above, the number of sickeners installed is not particularly limited for at least two or more sickeners, but sickeners generally have a diameter of 20 m or more, and the cost required for capital investment, as well as their operation and maintenance. Since the cost required for this is high, it is preferable to use the minimum necessary equipment from the viewpoint of economic efficiency. Therefore, the number of thickeners is more preferably two.

≪3. Application of nickel oxide ore to hydrometallurgy process ≫
The above-mentioned method for producing an ore slurry can be applied to the treatment in the ore slurry manufacturing process in the hydrometallurgical process of nickel oxide ore. The hydrometallurgy process for nickel oxide ore is a hydrometallurgy method for leaching and recovering nickel and cobalt from nickel oxide ore, for example, by using the HPAL method.

The wet smelting process consists of an ore slurry manufacturing step for preparing an ore slurry containing nickel oxide ore as a raw material, a leaching step in which an acid is added to the ore slurry to perform a leaching process, and the obtained leaching slurry is washed in multiple stages. A solid-liquid separation step in which the leachate residue is separated to obtain a leachate containing an impurity element together with nickel and cobalt, and a neutralized final liquid containing nickel and cobalt by adjusting the pH of the leachate and separating a neutralized starch containing an impurity element. It has a neutralization step of obtaining a nickel and a nickel recovery step of generating and recovering a mixed sulfide of nickel and cobalt by adding a sulfide agent to the neutralization final solution.

In the ore slurry manufacturing process in the wet smelting process, the raw material nickel oxide ore is crushed and sieved so as to have a predetermined particle size or less, and then water is added to prepare an ore slurry. The ore slurry is subjected to a concentration treatment using a thickener prior to being sent to the treatment in the leaching step of the next step to increase the slurry concentration.

At this time, in the concentration treatment of the ore slurry, at least two thickeners are used to thicken a predetermined ratio of the slurry, which does not contain the entire amount, in two steps. Then, the second-stage thickening for the slurry having a predetermined ratio after the first-stage thickening and the sickening for the slurry with the remaining ratio are performed by the same thickener. Since the specific processing operation is the same as the above-mentioned method for producing an ore slurry, detailed description here will be omitted.

In the ore slurry manufacturing step, the ore slurry is concentrated by such a treatment operation, and a concentrated ore slurry having an increased slurry density and solid content can be effectively obtained. Here, as will be described again, in the hydrometallurgical process of nickel oxide ore, the amount of nickel in the ore slurry supplied to the leaching step can be obtained from the following formula.
Amount of nickel supplied to the leaching process (t / day)
= Total slurry supply amount (m ³ / day) x nickel grade (mass%) x slurry density (density: g / cm ³ ) x solid content (solid%: mass%)

Therefore, since the slurry density and the solid content can be effectively increased by the above-mentioned concentration treatment in the ore slurry manufacturing step, the amount of nickel supplied to the leaching step of the next step can be increased. As a result, the amount of nickel in the leachate obtained through the treatment in the leaching step can be increased, and the amount of nickel produced by the hydrometallurgical process can be effectively improved.

Hereinafter, examples of the present invention will be described in more detail, but the present invention is not limited to the following examples.

Regarding the treatment in the ore slurry manufacturing process in the hydrometallurgical process of nickel oxide ore, the present invention was applied to obtain a concentrated ore slurry as follows.

Specifically, the pulverized nickel oxide ore was sieved and classified to obtain ore particles having a particle size of 1.7 mm or less (ore classification step). Next, by supplying water to the ore, a dilute ore slurry was obtained (slurry step). Here, when the same ore is processed, since the specific gravity of the ore to be a slurry is the same, the slurry density (g / cm ³ ) increases as the solid content (%) of the obtained slurry increases. That is, the solid content (%) of the slurry and the slurry density (g / cm ³ ) are in a proportional relationship.

Next, a concentration treatment was performed on the dilute ore slurry (slurry concentration step). As shown in FIG. 1, as a thickener facility, a facility equipped with two thickeners, a first thickener 11 and a second thickener 12, is used, and 31% by mass of the total amount of the dilute ore slurry is supplied to the first thickener 11. 69% by mass of the balance was supplied to the second thickener 12. After performing the first-stage thickening in the first thickener 11, the entire amount of the concentrated ore slurry is sent to the second thickener 12, and finally the total amount of the diluted ore slurry is thickened by the second thickener 12. To obtain a concentrated ore slurry. For the slurry in which the first-stage thickening was performed in the first thickener 11, the second-stage thickening was performed in the second thickener 12.

In the processing operation in such a slurry concentration step, the first thickener 11 and the second thickener 12 when the ratio (liquid feeding ratio) of distributing the dilute ore slurry to the first thickener 11 and the second thickener 12 are changed. The amount of thickener used to maintain the required clarity of the supernatant layer (sometimes called "turbidity") was investigated.

FIG. 4 shows the slurry density bottomed out from the second thickener when the liquid feeding ratio to the second thickener 12, that is, the ratio to be distributed to the second thickener 12, is changed, and the first thickener 11 and the first thickener 11 with respect to 1 ton of ore. 2 It is a graph which showed the value of the amount of the flocculant added by the thickener 12 and the increase / decrease ratio (%) with respect to each reference value.

As shown in FIG. 4, a predetermined ratio of the dilute ore slurry, which does not contain the entire amount, is sent to the first thickener 11 and the second stage with respect to the slurry that has undergone the first stage thickening in the first thickener 11. By performing the sickening and the sickening of the residual ratio of the slurry with the second thickener 12, the density of the obtained concentrated ore slurry is increased while appropriately suppressing the amount of the flocculant used. It turns out that it can be done.

In particular, the amount of flocculant used is minimized by setting the ratio of the diluted ore slurry to the second thickener 12, that is, the ratio of the slurry not sent to the first thickener 11 to more than 54% by mass and less than 78% by mass. It can be seen that a concentrated ore slurry having a high slurry density can be effectively obtained while suppressing the limit.

1,2,3 sickner equipment 11,21,31 1st sickner 12,22,32 2nd sickner 23,33 3rd sickner 34 4th sickner 12a sickner body 12b feed well

Claims (6)

A method for producing an ore slurry, which comprises concentrating a slurry containing a metal ore to produce an ore slurry to be subjected to a reaction.
With at least two sickeners
A predetermined ratio of the slurry that does not contain the entire amount is sickened in two steps.
The second-stage sickening for the slurry having the predetermined ratio and the sizing for the slurry with the remaining ratio after the first-stage sickening are performed by the same thickener.
A method for producing an ore slurry. The proportion of the balance is more than 54% by mass and less than 78% by mass.
The method for producing an ore slurry according to claim 1. The metal ore contains nickel oxide ore.
The method for producing an ore slurry according to claim 1 or 2. The ore particle size of the ore slurry is 1.7 mm or less.
The method for producing an ore slurry according to claim 3. The ore slurry is subjected to the reaction of acid leaching treatment.
The method for producing an ore slurry according to any one of claims 1 to 4. It is a hydrometallurgical method for nickel oxide ore.
The slurry manufacturing process for producing the nickel oxide ore slurry (ore slurry) and
Including a leaching step of adding an acid to the ore slurry to perform a leaching process.
In the slurry manufacturing process,
A process to concentrate the slurry containing crushed nickel oxide ore is performed.
In the concentration process,
Using at least two thickeners, a predetermined proportion of the slurry that does not contain the entire amount is thickened in two steps.
The second-stage sickening for the slurry having the predetermined ratio and the sizing for the slurry with the remaining ratio after the first-stage sickening are performed by the same thickener.
Hydrometallurgy method.

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