JP6418140B2 - Nickel smelting method, chlorine leaching method - Google Patents

Description

  The present invention relates to a nickel smelting method, and more specifically, by blowing chlorine gas into a sulfide containing nickel, the nickel is leached from the sulfide, and nickel is extracted from the obtained leachate. The present invention relates to a method for hydrometallizing nickel to be recovered.

  As a nickel smelting method, a hydrometallurgical method using chlorine leaching is known. (For example, patent document 1). In this method, a nickel-containing raw material is made into a slurry, and in a step of leaching nickel by blowing chlorine (hereinafter also referred to as “chlorine leaching step”), a crude nickel chloride solution is obtained, and then impurities are removed to obtain high purity. After obtaining the nickel chloride solution, electro nickel is produced by electrowinning.

  In this nickel smelting method, the chlorine leaching rate is improved by a method for improving the water balance (in / out of the liquid held in the system) which is a basic problem in the hydrometallurgical method (for example, Patent Document 2) or by changing the raw material. Various technical improvements, such as an improvement method (for example, Patent Document 3) for a problem to be reduced, have been added, and are applied to the production of electrolytic nickel.

  Here, in this nickel smelting method, as shown in FIG. 2, a chlorine leaching process and a cementation (CM) process using copper (Cu) as a medium for taking in chlorine gas, removing sulfur, etc. One of the big features is that is a set.

  Conventionally, nickel matte obtained by dry-treating nickel oxide ore and MS (mixed sulfide) obtained by wet-treating low-grade nickel oxide ore have been used as nickel-containing raw materials. However, obtaining nickel mats has become difficult year by year due to depletion of nickel oxide ore suitable for producing nickel mats and other reasons.

  As can be seen from the process diagram of FIG. 2, in the cementation process in the conventional nickel smelting method, the nickel mat to be added acts to reduce copper ions (CuCl) to solid (CuS). Addition of nickel matte was essential for immobilization.

  However, as described above, nickel mats are difficult to obtain, and a smelting method capable of effectively leaching chlorine without using nickel mats is desired.

Japanese Patent Publication No. 7-091599 Japanese Patent Laying-Open No. 2015-081371 JP 2013-189670 A

  The present invention has been proposed in view of such circumstances, and effectively leaches and recovers nickel from sulfides containing nickel such as MS without using a nickel mat that is difficult to obtain. An object is to provide a method for smelting nickel.

  The inventors of the present invention have made extensive studies in order to solve the above-described problems. As a result, when performing chlorine leaching treatment by blowing chlorine gas into the slurry containing nickel, nickel can be effectively leached by performing the leaching treatment in a state where iron ions coexist. Since the cementation treatment for the obtained leachate is not necessary, it has been found that it is not necessary to use a conventionally used nickel mat, and the present invention has been completed. That is, the present invention provides the following.

  (1) A first invention of the present invention is a chlorine leaching step in which a sulfide containing nickel is made into a slurry, and chlorine gas is blown into the slurry to leached nickel to obtain a leaching solution and a leaching residue; And a purification step of separating and removing impurities containing at least iron from the leachate, wherein the chlorine leaching step leaches chlorine in the presence of iron ions in the slurry.

  (2) The second invention of the present invention, in the first invention, further includes an iron starch dissolving step for dissolving a precipitate containing iron, and in the iron starch dissolving step, The separated iron starch is dissolved to produce a solution containing iron ions (iron ion-containing solution), and the iron ion-containing solution is added to the slurry leached in the chlorine leaching step. It is a smelting method.

  (3) According to a third aspect of the present invention, in the second aspect of the present invention, in the iron starch dissolution step, the leaching residue generated in the chlorine leaching step is dissolved to form an iron ion-containing solution. It is a smelting method.

  (4) According to a fourth aspect of the present invention, in any of the first to third aspects, the sulfide containing nickel is a sulfide obtained by adding a sulfiding agent to an acidic solution containing nickel. This is a method for smelting nickel.

  (5) According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the sulfide containing nickel has a cumulative 90% diameter (D90) of the particle size distribution at the start of the chlorine leaching. ) Is a nickel smelting method of 40 μm or less.

  (6) A sixth invention of the present invention is a chlorine leaching method in which a sulfide containing nickel is used as a slurry, and chlorine gas is blown into the slurry to leaching nickel, and iron ions are contained in the slurry. This is a chlorine leaching method in which chlorine is leached in the presence of water.

  According to the present invention, it is possible to provide a nickel smelting method capable of effectively leaching and recovering nickel from a sulfide containing nickel without using a nickel mat that is difficult to obtain.

It is process drawing which shows an example of the smelting method of nickel which concerns on this invention. It is process drawing which shows an example of the conventional smelting method of nickel. In Example 1, it is a graph which shows transition of the consumption amount of the inhaled chlorine gas with respect to reaction time (leaching process time).

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

<< 1. Overview >>
(Outline of the nickel smelting method according to the present invention)
In the nickel smelting method according to the present invention, a sulfide containing nickel is made into a slurry, chlorine gas is blown into the slurry, and nickel is leached into the solution to be separated into a leaching solution and a leaching residue. This is a nickel smelting method that obtains nickel by separating slag.

  Specifically, the nickel smelting method according to the present invention includes a chlorine leaching step of leaching a sulfide containing nickel into a slurry, and a purified liquid for separating and removing impurities including at least iron from the obtained leachate. Process. And in this nickel smelting method, in the chlorine leaching process in the chlorine leaching process, iron ions coexist in the slurry and leaching chlorine. In other words, chlorine leaching is performed using iron as a medium.

  According to such a nickel smelting method, nickel can be efficiently leached from sulfides such as MS as a raw material, and copper is not used as a medium, so that a large amount of copper is contained in the obtained leachate. Not included. This eliminates the need for a cementation step for fixing copper in the leachate as in the prior art, and eliminates the need for the nickel mat used in the cementation process.

  In addition, this nickel smelting method includes an iron starch dissolution process that dissolves iron deposits, and the iron starch separated and removed from the leachate in the liquid purification process is dissolved to produce an iron ion-containing solution. The iron ion-containing solution is repeatedly added to the slurry to be leached in the leaching step. Thus, iron ions can be effectively circulated in the system, and the nickel smelting process can be efficiently advanced.

(Conventional nickel smelting method)
Here, in the conventional nickel smelting method, as shown in FIG. 2, a chlorine leaching process using copper as a medium and a cementation process for fixing copper in the leaching solution were performed.

  Specifically, first, a mixed sulfide (MS) slurry containing nickel sulfide and cobalt sulfide as raw materials is charged into a chlorine leaching reaction tank, and nickel and a target metal are added by blowing chlorine gas. Cobalt is leached (chlorine leaching process). In this chlorine leaching reaction, copper (copper sulfide, etc.) contained in MS becomes divalent copper ions by chlorine gas, and nickel, etc. leaches into the solution from nickel sulfide in MS by oxidative leaching with this divalent copper ions. Is done. On the other hand, chlorine gas is reduced by copper sulfide or the like and dissolved in the solution, and the obtained leachate becomes a crude nickel chloride solution.

  In this chlorine leaching process, iron and the like are also leached in addition to nickel and cobalt and dissolved in the leachate. Moreover, the chlorine gas used for chlorine leaching is, for example, chlorine gas recovered from the subsequent electrowinning process or the like in the nickel smelting method.

  Next, the leachate obtained in the chlorine leaching process is separated from the leaching residue and transferred to the cementation process. In this cementation process, nickel matte is added to the leachate, and the copper dissolved in the leachate is reduced and fixed as copper sulfide and deposited. Then, by filtering off after the completion of the cementation reaction, a cementation residue mainly composed of copper sulfide and a cementation final solution are obtained.

  The obtained cementation final solution is subsequently transferred to the liquid purification process, and after impurities such as iron and cobalt are removed, it is transferred to the electrowinning process. In the electrolytic collection process, nickel is produced by electrolysis using the nickel chloride solution from which impurities have been removed in the liquid purification process as an electrolytic solution. Note that the electrolytic waste liquid ("Ni poor liquid" in FIG. 2) is discharged from the electrolytic cell after electrolysis, and the electrolytic waste liquid is returned to the chlorine leaching step. Further, as described above, the chlorine gas generated from the anode of the electrolytic cell is recovered and returned to the chlorine leaching process and used for the chlorine leaching process.

  On the other hand, the cementation residue mainly composed of copper sulfide produced in the cementation process is repeatedly charged into a chlorine leaching reaction tank and used to dissolve chlorine gas in the leaching solution. Oxidized to form divalent copper ions and used for oxidative leaching.

  Thus, in the conventional nickel smelting method, a chlorine leaching process using copper as a medium and a cementation process for fixing copper in the leachate are performed, that is, an aspect in which copper ions circulate. It was. In the cementation process, it is necessary to add nickel matte to reduce and fix the copper dissolved in the leachate.

  However, in recent years, nickel mats are difficult to obtain, and changes in the raw material ratio, that is, technological development for treating MS with a small amount of nickel mats are being promoted, but the need for nickel mats remains unchanged. In addition, if it becomes impossible to obtain a nickel mat, there is a possibility that it may hinder the continuation of operation.

≪2. Nickel smelting method >>
Therefore, the present inventors have found that by using iron as a medium instead of copper as a medium, it is not necessary to insert a nickel mat.

  Specifically, the nickel smelting method according to the present invention is obtained by chlorine leaching step S1 in which chlorine gas is blown into a sulfide slurry containing nickel such as MS and chlorine is leached, and chlorine leaching. And a cleaning step S2 for separating and removing impurities such as iron from the leachate. The nickel smelting method is characterized in that, in the chlorine leaching step, chlorine leaching is performed in a state where iron ions coexist in the nickel-containing sulfide slurry.

  FIG. 1 is a process diagram showing an example of a nickel smelting method according to the present invention. As described above, this nickel smelting method is characterized by chlorine leaching in the presence of iron ions, and as shown in FIG. 1, in the conventional method, the copper in the leachate is fixed using a nickel mat. Does not have a cementation process. Hereinafter, each step will be described in detail.

<2-1. About each process>
(1) Chlorine leaching process In the chlorine leaching process S1, a metal such as nickel contained in the sulfide is blown into a slurry of sulfide containing nickel (hereinafter also simply referred to as “sulfide”). Is leached into the solution. At this time, chlorine is leached in a state where iron ions coexist in the slurry.

  Specifically, in this chlorine leaching step S1, a nickel-containing sulfide slurry is charged into a chlorine leaching reaction vessel, and for example, chlorine gas recovered from a subsequent electrowinning step is blown into the slurry in the reaction vessel. .

  The sulfide containing nickel is not particularly limited. For example, a sulfurizing agent such as hydrogen sulfide gas is added to a leachate (sulfuric acid solution) obtained by leaching nickel oxide ore containing nickel with sulfuric acid or the like. And sulfides obtained by sulfidation. A sulfide obtained by adding a sulfiding agent to an acidic solution containing nickel is nickel sulfide, cobalt sulfide, and mixed sulfide (MS). MS contains the iron contained in the nickel oxide ore. Therefore, as will be described in detail later, the leachate and the leach residue obtained through the leaching process in the chlorine leaching step S1 contain iron, and this iron is recovered and repeatedly added to the target slurry of the chlorine leaching process. Thus, the nickel smelting process can be efficiently advanced.

  Further, the sulfide containing nickel such as MS is not particularly limited, but the particle size at the start of the chlorine leaching treatment is preferably 115 μm or less at a cumulative 90% diameter (D90) of the particle size distribution, and 40 μm or less. It is more preferable that it is 20 μm or less. In particular, by using a sulfide having a D90 diameter of 40 μm or less as a raw material, nickel is effectively leached in a short reaction time, and the nickel chlorine leaching rate can be improved. Moreover, the lower limit of the particle size of the sulfide is not particularly limited, but when the D90 diameter is less than 10 μm, the reactivity of the sulfide powder increases, and heat and heat are generated only by leaving it in the air. The above problem occurs.

  The sulfide having a desired particle size can be prepared by using a known pulverizer such as a ball mill and controlling the pulverization time and the number of pulverization media.

  The sulfide containing nickel can be repulped with an acidic hydrochloric acid solution to be slurried. Moreover, as the hydrochloric acid acidic solution, for example, a nickel chloride solution (nickel poor solution) obtained through a subsequent electrowinning step can be used.

Here, in the chlorine leaching process in the chlorine leaching step S1, chlorine gas is blown into a slurry of nickel-containing sulfide (main component: NiS) in the presence of iron ions, thereby being included in the sulfide. Metals such as nickel and cobalt are leached into the solution. More specifically, in this chlorine leaching step S1, reactions shown in the following formulas (I) and (II) occur.
Cl ₂ + 2Fe ²⁺ → 2Cl ⁻ + 2Fe ³⁺ (I)
NiS + 2Fe ³⁺ → Ni ²⁺ + S ⁰ + 2Fe ²⁺ (II)

  That is, in the chlorine leaching step S1, chlorine gas is blown in the state where iron ions coexist in the slurry containing sulfide, whereby the divalent iron ions are oxidized into trivalent iron ions by the chlorine gas (see above). (Formula (I)), and then the oxidized trivalent iron ion causes nickel or the like contained in the sulfide to be so-called oxidatively leached (formula (II) above), and a leachate containing a metal such as nickel Produces. In this chlorine leaching reaction, as shown in the above formula (I), the blown chlorine gas is easily reduced by divalent iron ions having high reducing power coexisting in the slurry, It will be captured. Therefore, it proceeds rapidly to the reaction of the above formula (II), and a metal such as nickel is efficiently leached into the solution.

  In the chlorine leaching reaction, the above-described reaction proceeds efficiently, effectively leaching a metal such as nickel, and most of iron is oxidized by chlorine gas to become trivalent iron ions. The potential (ORP) can be suitably adjusted to the range. For example, the ORP is adjusted to a range of 540 mV to 570 mV with a measured value using a silver-silver chloride electrode as a reference electrode.

  The leachate produced by the chlorine leaching reaction is a nickel chloride solution obtained by dissolving the blown chlorine gas and taking it in as chloride ions, and leaching nickel from NiS, which is the main component of sulfide. It is. Further, the nickel chloride solution obtained after the chlorine leaching reaction contains divalent iron ions as shown in the above formula (II).

  The produced nickel chloride solution is a solution containing iron ions as well as cobalt, which is an impurity in the nickel refining method, and is also referred to as a “crude nickel chloride solution” as appropriate.

  On the other hand, in this chlorine leaching reaction, a leachate from which nickel has been leached is generated and a leach residue that is a precipitate containing sulfur as a main component is generated (the above formula (II)). Here, the produced leaching residue includes iron precipitates (iron starch) such as iron sulfide and iron chloride. As will be described in detail later, iron contained in the leaching residue produced by the chlorine leaching reaction. By dissolving starch and producing a solution containing iron ions, and repeatedly adding the iron ion-containing solution to the slurry subject to chlorine leaching treatment, the nickel smelting process can be efficiently advanced. it can.

(2) Liquid Purification Process The liquid purification process S2 separates and removes impurities including at least iron from the leachate obtained through the chlorine leaching process S1. In this nickel smelting method, as described above, since the chlorine leaching treatment using iron as a medium is performed instead of the chlorine leaching treatment using copper as a medium, the copper contained in the leachate as in the prior art is used. A cementation process for immobilizing ions is not required. Therefore, the leachate obtained through the chlorine leaching step S1 is directly transferred to the liquid purification step S2.

  Specifically, in this liquid purification step S2, impurities other than nickel are separated and removed from the leachate, and a nickel chloride solution for smelting nickel is obtained, for example, by electrolytic collection.

  This liquid purification process S2 has at least a deironing process for separating and removing iron from the leachate. In addition, a decobalt process, a delead process, a dezinc process, and the like can be provided. In addition, the target element to be separated and removed in the liquid purification step S2 can be appropriately determined according to the type of sulfide as a raw material.

  A method for separating and removing impurities such as iron from the leachate in the iron removal step is not particularly limited, and for example, an oxidation neutralization method can be used. The oxidative neutralization method is to separate and remove iron, which is an impurity, as a precipitate of hydroxide by adding chlorine gas as an oxidizing agent and carbonate as an alkaline agent to the leachate. When the heavy metal becomes a higher-order oxide ion, it utilizes the property of being easily a hydroxide in a low pH region.

  As the oxidant, hypochlorous acid, oxygen, air, etc. can be used as the oxidant in addition to the chlorine gas. As the alkali agent, hydroxides such as caustic soda, ammonia and the like can be used in addition to carbonates. These chemicals can be used in combination suitable for the process conditions. In the nickel smelting process, it is preferable to use chlorine gas as the oxidizing agent and carbonate as the alkaline agent. In addition, chlorine gas as an oxidizing agent is a strong oxidizing agent generated in the process and easy to use, and carbonate as an alkaline agent can control the ion concentration of nickel or the like in the entire process and at the time of oxidation neutralization. This is preferable because of its excellent reactivity.

More specifically, in the iron removal step, for example, iron is separated and removed as a precipitate (iron starch) by the reaction shown in the following formula (III). In addition, the following reaction formula shows the reaction of the deironing process by the oxidation neutralization method using chlorine gas as an oxidizing agent and nickel carbonate as an alkaline agent.
2Fe ²⁺ + Cl ₂ + 3NiCO ₃ + 3H ₂ O →
2Fe (OH) ₃ + 3Ni ²⁺ + 2Cl ⁻ + 3CO ₂ (III)

  In the iron removal treatment using such an oxidative neutralization method, iron ions are reduced when they are fixed as hydroxides, so that a conventional nickel mat is not required.

  In addition, even in the case of having a cobalt removal step for separating and removing cobalt in the leachate, a zinc removal step for separating and removing zinc, etc., in the liquid purification step S2, the oxidation neutralization method described above in each step is performed. By using it, impurities can be separated and removed as a precipitate.

  By performing the liquid purification process in the liquid purification step S2, a nickel chloride solution that is a leachate from which impurities have been removed can be obtained. This purified nickel chloride solution is used, for example, as an electrolytic solution in an electrowinning method, and nickel can be recovered by generating electric nickel.

  On the other hand, in the liquid purification process S2, a precipitate of impurities contained in the leachate is generated. Specifically, an iron precipitate (iron starch) generated by the iron removal treatment in the iron removal step is generated. This iron starch is a hydroxide precipitate when, for example, an oxidation neutralization method is used. The iron starch produced in this way is transferred to the iron starch dissolving step in the next step.

(3) Iron starch dissolution process In the iron starch dissolution process S3, the iron starch obtained by the iron removal treatment in the liquid purification process S2 is dissolved to produce a solution containing iron ions (iron ion-containing solution). Let

  Here, in the conventional nickel smelting method, the entire amount of the iron starch produced by subjecting the leachate (leachate that has undergone the cementation process) to purification treatment has been discharged out of the system.

  On the other hand, in the nickel smelting method according to the present invention, the iron starch obtained from the liquid purification step S2 is dissolved in, for example, a hydrochloric acid acidic solution to generate an iron ion-containing solution. And the obtained iron ion containing solution is added to the slurry of the sulfide containing nickel used as the process target in chlorine leaching process S1 mentioned above. In this way, the iron starch obtained from the liquid purification step S2 is recovered, and iron ions based on the iron starch are added to the sulfide slurry so that the iron ions are effectively contained in the system. The nickel smelting process can proceed efficiently.

  Specifically, in this nickel smelting method, iron is transported as “iron ions” in the section from the chlorine leaching process in the chlorine leaching process to the deironing process in the deironing process. In the section from the iron removal treatment in the iron removal step to the dissolution treatment in the iron starch dissolution step, it is transferred as “hydroxide solid”. And then, iron circulates in this section and advances the chlorine leaching reaction.

  Moreover, in the iron starch dissolution step S3, not only the iron starch obtained from the liquid purification step S2, but also the leaching residue generated by the chlorine leaching process in the chlorine leaching step S1 can be dissolved together. The leaching residue produced by the chlorine leaching treatment also includes iron starches such as iron sulfide and iron chloride. The iron starch is mixed with the iron starch obtained from the liquid purification step S2, and an acidic hydrochloric acid solution or the like. By using and dissolving, an iron ion-containing solution can be generated and similarly returned to the sulfide slurry in the chlorine leaching step.

  In this manner, in the iron starch dissolution step S3, by dissolving the leaching residue generated by the chlorine leaching treatment, iron ions circulating in the system can be increased, and the nickel smelting process can be performed more efficiently. Can be advanced. In addition, since the leaching residue generated by the chlorine leaching process also includes nickel that could not be leached by the leaching process, by returning the solution obtained by dissolving the leaching residue to the slurry, The nickel can again be subjected to a leaching process.

  In the iron starch dissolution step S3, the solution for dissolving the iron starch obtained from the liquid purification step S2 and the leaching residue obtained from the chlorine leaching step S1 is not particularly limited. From the viewpoint that an iron ion-containing solution obtained by dissolving iron starch is repeatedly circulated in the system, it is preferably a hydrochloric acid acidic solution. Specifically, as the hydrochloric acid acidic solution, for example, a nickel chloride solution (nickel poor solution) obtained through a subsequent electrowinning step can be used.

(4) Electrolytic collection step In the electrolytic collection step S4, electronickel is obtained by an electrolytic collection method from the nickel chloride solution purified through the liquid purification step S2. That is, electric nickel is generated by electrolytic treatment using the purified nickel chloride solution as an electrolytic solution.

  Specifically, in the electrowinning step S4, nickel ions in the nickel chloride solution as the electrolytic solution are deposited as metal (electrical nickel) on the cathode side. On the other hand, on the anode side, chlorine ions in the nickel chloride solution are generated as chlorine gas. The chlorine gas generated at the anode can be used as, for example, recovered chlorine gas in the chlorine leaching step S1.

  In addition, in this Embodiment, although the method of carrying out the electrowinning as an electric nickel from the nickel chloride solution obtained through the liquid purification process S2 was shown as an example, it is not restricted to this as a nickel smelting method.

<2-2. About effect>
As described above, the nickel smelting method according to the present invention uses a sulfide containing nickel as a slurry, and chlorine gas is blown into the slurry to leached nickel to obtain a leachate and a leach residue. It includes a leaching step S1 and a cleaning step S2 for separating and removing at least iron-containing impurities from the leaching solution. In the chlorine leaching step S1, chlorine ions are leached in the presence of iron ions in the slurry. That is, chlorine leaching is performed using iron as a medium.

  According to such a nickel smelting method, the chlorine gas blown in the chlorine leaching reaction is efficiently taken into the solution, and the oxidative leaching of iron ions oxidized by the chlorine gas causes the raw material MS or the like to Nickel can be efficiently leached from the sulfide. And in this chlorine leaching reaction, since copper is not used as a medium, a large amount of copper is not contained in the obtained leachate, and a cementation step for fixing copper in the leachate is not required as in the prior art. . Then, since the nickel mat | matte required for the cementation process becomes unnecessary, the problem that operation efficiency falls with the difficulty of acquisition of a nickel mat | matte can also be solved.

  Further, in this nickel smelting method, an iron starch dissolution step S3 for dissolving iron deposits is provided, and the iron starch separated and removed from the leachate in the liquid purification step S2 is dissolved to provide an iron ion-containing solution. And the iron ion-containing solution is repeatedly added to the slurry to be subjected to chlorine leaching in the chlorine leaching step S1. Thus, iron ions can be effectively circulated in the system, and the nickel smelting process can be efficiently advanced.

  In the conventional nickel smelting method, chlorine leaching treatment is performed using copper as a medium. The copper input includes sulfides such as MS used as a raw material and nickel mat used in the cementation process. Derived from copper. If the copper ion concentration in the system increases too much, the amount of copper in the solution (cementation final solution) in the cementation process increases, which may increase the quality of impurities in the nickel, and conversely If the ion concentration is low, chlorine gas is not efficiently absorbed in the chlorine leaching process and is discharged out of the system, resulting in a decrease in nickel leaching rate. For this reason, the amount of copper is kept substantially constant based on the amount of treatment. For example, when the amount of processing increases, copper is separated and removed by intermittently removing copper from the leachate as the amount increases, so that the amount of copper in the circulating system is kept almost constant. It was.

  On the other hand, in the nickel smelting method according to the present invention, iron is used as a medium and chlorine ions are leached in the presence of iron ions. Therefore, from the leachate generated by the chlorine leaching, or from the leach residue. By adjusting the amount of dissolved iron starch, the amount of iron ions as a medium can be easily adjusted.

  Here, when MS is used as a sulfide containing nickel as a raw material, for example, copper is slightly contained in the MS. In the nickel smelting method according to the present invention, copper is not used as a medium, and therefore there is no cementation step. Therefore, it is conceivable that the amount of copper in the system increases as the MS throughput increases. However, the amount of copper in the MS is a very small amount of the 0.0 n% level, and Since there is no need to insert a nickel matte containing copper at the n% level, the copper in the system can be kept extremely low.

  Still, if the treatment is continued for a period of about 10 times longer than the conventional case, there is a possibility that a problem associated with an increase in the amount of copper may occur. For example, copper in the leachate is separated and removed as appropriate. It is preferable to perform a copper removal electrolytic treatment for the purpose. In addition, as a copper removal method, it is not limited to a copper removal electrolysis process, What is necessary is just to separate and remove by well-known methods, such as an ion exchange process and a solvent extraction process.

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

[Example 1]
Using MS having the composition shown in Table 1 as a raw material, chlorine leaching treatment was performed by blowing chlorine gas into this MS slurry (chlorine leaching initial solution, composition shown in Table 2 below). At this time, leaching was performed in a state where iron ions were allowed to coexist in the slurry. In addition, about MS, it grind | pulverizes by a planetary ball mill (the product made from Fritsch, model number P-5), and the particle size is 12 micrometers, 17 micrometers, 36 micrometers, 42 micrometers, and 112 micrometers in the accumulation 90% diameter (D90) in a particle size distribution. Each one was prepared and used.

(Leaching condition)
MS slurry concentration: 100 g / L
Iron ion concentration: 40 g / L
Chlorine leaching starting solution pH: 1.0 (temperature 100 ° C.)
Reaction temperature: 100 ° C. to 102 ° C.
Oxidation reduction potential (ORP): 560 mV (reference electrode: silver / silver chloride electrode)

FIG. 3 is a graph showing the transition of the amount of chlorine gas consumed with respect to the reaction time (leaching treatment time). The consumption amount of chlorine gas indicates the amount of chlorine (g) taken into the solution after being dissolved. As shown in FIG. 3 , by performing chlorine leaching treatment in a state where iron ions coexist in the slurry, chlorine gas is taken in as the reaction time elapses, and the chlorine leaching reaction proceeds efficiently. (See the above formulas (I) and (II)). That is, it can be seen that the iron ions coexisted in the slurry are effectively acting as a medium in the chlorine leaching process. In the chlorine leaching process, the theoretical value of chlorine gas consumption when the reaction time is 8 hours is 18 g.

  Moreover, from this result, it can be seen that the smaller the MS particle size (D90), the greater the consumption of chlorine gas.

[Example 2]
Using the same MS-containing slurry as in Example 1 (the composition is shown in Table 2 above), iron ions were allowed to coexist in the slurry, and the chlorine leaching treatment was performed under the same leaching conditions with a reaction time of 24 hours. It was. As MS, one having a composition shown in Table 1 and having a particle size of 112 μm (D90) was used.

  As a result, the amount of chlorine gas consumed was 14.5 g, which was sufficiently taken into the solution. Moreover, the nickel leaching rate from MS at this time was 49.4%.

  Thereafter, the obtained leachate was subjected to a liquid purification treatment to separate and remove impurities, and electrolysis was performed using the leachate after removing the impurities as an electrolytic solution. As a result, electric nickel could be produced without problems.

[Example 3]
The same procedure as in Example 2 was performed except that MS having a particle size of 42 μm (D90) was used and the chlorine leaching treatment was performed with a reaction time of 8.2 hours.

  As a result, the amount of chlorine gas consumed was 14.5 g, which was sufficiently taken into the solution. Moreover, the nickel leaching rate from MS at this time was 76.1%.

  Thereafter, the obtained leachate was subjected to a liquid purification treatment to separate and remove impurities, and electrolysis was performed using the leachate after removing the impurities as an electrolytic solution. As a result, electric nickel could be produced without problems.

[Example 4]
Example 2 was the same as Example 2 except that MS having a particle size of 42 μm (D90) was used, and the reaction time was 7.9 hours and the chlorine leaching treatment was performed.

  As a result, the amount of chlorine gas consumed was 14.5 g, which was sufficiently taken into the solution. Moreover, the nickel leaching rate from MS at this time was 73.4%.

  Thereafter, the obtained leachate was subjected to a liquid purification treatment to separate and remove impurities, and electrolysis was performed using the leachate after removing the impurities as an electrolytic solution. As a result, electric nickel could be produced without problems.

[Example 5]
The same procedure as in Example 2 was performed except that MS having a particle size of 17 μm (D90) was used and the chlorine leaching treatment was performed with a reaction time of 4 hours.

  As a result, the amount of chlorine gas consumed was 14.5 g, which was sufficiently taken into the solution. Moreover, the nickel leaching rate from MS at this time was 84.9%.

  Thereafter, the obtained leachate was subjected to a liquid purification treatment to separate and remove impurities, and electrolysis was performed using the leachate after removing the impurities as an electrolytic solution. As a result, electric nickel could be produced without problems.

[Example 6]
The same procedure as in Example 2 was performed except that MS having a particle size of 12 μm (D90) was used and the chlorine leaching treatment was performed with a reaction time of 4 hours.

  As a result, the amount of chlorine gas consumed was 14.5 g, which was sufficiently taken into the solution. Moreover, the nickel leaching rate from MS at this time was 92.9%.

  Thereafter, the obtained leachate was subjected to a liquid purification treatment to separate and remove impurities, and electrolysis was performed using the leachate after removing the impurities as an electrolytic solution. As a result, electric nickel could be produced without problems.

[Reference Example 1]
In Reference Example 1, a chlorine leaching process was performed using copper as a medium as in the past. Specifically, using the MS-containing slurry whose composition is shown in Table 3 below, chlorine leaching treatment was performed in the presence of copper ions.

  As a result of this chlorine leaching treatment, the reaction time for the consumed chlorine gas to reach 14.5 g was about 2 hours, and the nickel leaching rate from MS at this time was 92.0%.

  However, after that, a cementation treatment for immobilizing and removing copper in the leachate was required for the obtained leachate, and nickel matte was required for the cementation treatment.

  Table 4 below summarizes the results of chlorine leaching treatment in Examples 2 to 6 and Reference Example 1. Table 4 shows the ratio of elemental components contained in the leaching solution and leaching residue obtained by the chlorine leaching treatment, and the leaching rate of nickel from the MS by the chlorine leaching treatment.

Claims (5)

A chlorine leaching step in which a sulfide containing nickel is made into a slurry, and chlorine gas is blown into the slurry to leaching nickel to obtain a leachate and a leach residue;
A liquid purification step for separating and removing impurities containing at least iron from the leachate;
An iron starch dissolving step for dissolving the iron-containing precipitate ,
In the chlorine leaching step, leaching of chlorine with iron ions coexisting in the slurry ,
In the iron starch dissolution step, at least the iron starch separated and removed in the liquid purification step is dissolved to produce a solution containing iron ions (iron ion-containing solution), and the iron ion-containing solution is added to the chlorine A method for smelting nickel to be added to the slurry that leaches chlorine in the leaching step . In the iron sediment was dissolved step, the in the cleaning step in addition to Tetsuori product is separated and removed, according to claim 1 to produce an iron ion-containing solution to dissolve the resulting leach residue by the chlorine leaching step Smelting method of nickel. Sulfides containing the nickel smelting process of nickel according to claim 1 or 2 sulfides obtained by adding a sulfurizing agent to an acidic solution containing nickel. The nickel-containing smelting method according to any one of claims 1 to 3 , wherein the sulfide containing nickel has a cumulative 90% diameter (D90) of particle size distribution of 40 µm or less at the start of chlorine leaching. . A chlorine leaching method in which sulfide containing nickel is made into a slurry, and chlorine gas is blown into the slurry to leaching nickel.
In the slurry, iron ions are allowed to coexist, and chlorine leaching is performed.
The iron ions are separated from the leachate obtained by the chlorine leaching, and a solution containing iron ions generated by dissolving the iron starch (iron ion-containing solution) is added to the slurry. Chlorine leaching method supplied by

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