KR102152923B1 - Manufacturing Method of Highly Purified Nickel Sulfate from the raw materials of Nickel, Cobalt and Manganese Mixed Sulfide Precipitation - Google Patents

Abstract

The present invention relates to a method for manufacturing nickel sulfate used for secondary battery cathode materials, industrial electrolytic nickel plating, and electroless nickel plating, and more particularly, nickel and cobalt containing calcium under a continuous process including a recycling process. And manganese-mixed sulfide raw materials extract more than 97% of nickel, minimize the use of organic solvents and discharge of wastewater, and additionally recover cobalt, zinc, and manganese components as by-products, and produce high-purity sodium sulfate. It relates to a method for producing a possible high purity nickel sulfate.

Description

Manufacturing Method of Highly Purified Nickel Sulfate from the raw materials of Nickel, Cobalt and Manganese Mixed Sulfide Precipitation}

The present invention relates to a method of manufacturing nickel sulfate used for secondary battery cathode materials, industrial electrolytic nickel plating, and electroless nickel plating, and more particularly, nickel and cobalt containing calcium under a continuous process including a recycling process. In addition to extracting more than 97% of nickel from the raw materials of manganese mixed sulfide and minimizing the use of organic solvents and the discharge of wastewater, it is also possible to recover cobalt aqueous solution, zinc and manganese components as additional by-products, and produce high-purity sodium sulfate. The present invention relates to a method for producing high purity nickel sulfate prepared from a mixture of nickel, cobalt and manganese sulfides containing calcium.

Nickel sulfate is mainly used for electroless electroplating or electrolytic electroplating to manufacture magnetic storage media, PCB boards, electrodes and current collectors of various electronic components, and electroless electroplating or electrolytic electroplating to manufacture general industrial or decorative parts. It has been used, and in recent years, it has attracted great attention as a core basic raw material in manufacturing a cathode material for a lithium secondary battery.

In general, nickel sulfate is a hexahydrate crystal, and it has been known that a nickel content of 99% or more and a crystal size of about several mm are preferable for use in the above-described purposes. In particular, the crystal structure of nickel sulfate hexahydrate has an α-crystal structure of β -Since the size of the crystal is larger than that of the crystal structure, commercially, manufacturing technology to produce α-crystal structure is common, and nickel metal (ingot, bracket, granule, powder, etc.), nickel mat, nickel concentrate, metal smelting or refining process It can be manufactured through wet smelting using various raw materials such as by-product sludge, but commercially, it is common to use nickel metal or nickel mat as a raw material, and recently, nickel mat, nickel concentrate, by-product sludge in metal smelting or refining process, etc. Manufacturing technology using the is being developed.

In particular, the demand for nickel sulfate is rapidly increasing due to the increase in demand for secondary batteries, and in the nickel mines, sales of nickel raw materials are reduced for the purpose of increasing the added value of nickel, and the trend is rapidly shifting to the trend of manufacturing and supplying nickel sulfate. The supply of high-quality nickel raw materials is continuously decreasing, and it is mainly supplied with low-quality nickel raw materials with low nickel purity and high impurity content.Therefore, it is necessary to develop high-purity nickel sulfate manufacturing technology using calcium-containing nickel, cobalt, and manganese mixed sulfides.

In general, partial crystallization, fractional distillation, and solvent extraction are known as a method of removing impurities from the nickel sulfate leachate containing cobalt, but the solvent extraction method is currently most commonly used commercially.

Looking at such a solvent extraction method, alkali metal compounds such as lime and limestone or alkaline earth metal compounds or alkali compounds such as NaOH, NH ₃ , NH ₄ OH are used as neutralizing agents that are essentially used to control the pH during solvent extraction, but alkali metal compounds Alternatively, in the case of alkaline earth metal compounds, carbon dioxide is discharged during the extraction reaction, causing global warming problems.In the case of NaOH, NH ₃ , NH ₄ OH, etc., Na, NH ₃ components are extracted together with Ni and Co in the solvent extraction process and sulfuric acid It has been pointed out as a problem that the purity of nickel crystals and cobalt sulfate crystals is lowered.

In Korean Patent Registration No. 10-0981366, the nickel sulfate crystal seed prepared in advance was added to the nickel sulfate aqueous solution and the crystal was grown step by step, but the process time was lengthened and wastewater was generated because the sample had to be separated and added to the concentrate at each step. There is a problem in that it is not an efficient method, such as a large amount of nickel and a decrease in nickel yield.

In order to solve the above problem, Korean Patent Registration No. 10-1191042 discloses that when raw materials such as nickel concentrate or nickel mat are leached in sulfuric acid, the nickel particles obtained by performing an atmospheric pressure heating reaction in advance before using a pressure heating reactor are used. The efficiency and economy of the leaching process were improved by performing processes such as controlling the size to be fine. However, since the nickel concentrate or nickel mat is treated as a raw material, a separate pretreatment is not required, and therefore, there is a problem that it cannot be applied to other raw materials requiring pretreatment.

In addition, Korean Patent Registration No. 10-1412462 replaces nickel concentrate or nickel meth and uses products processed primary or secondary from ore containing nickel, such as'nickel hydroxide and cobalt hydroxide' (hereinafter referred to as Ni-Co MHP). Nickel sulfate is produced using a two-stage leaching tank consisting of an atmospheric pressure heating reaction tank and a pressurized heating reaction tank, or in Korean Patent No. 10-1535250, nickel sulfate is used as a single leaching tank of the atmospheric pressure heating reaction tank. The manufacturing process was presented.

However, to remove the Cl component from the raw materials, a pretreatment process using a cleaning method was proposed.The initial investment cost for counter current decantation cleaning process, ball mill and filtering cleaning process, or repulping reactor and filtering cleaning process There is a problem in that the operation cost is excessive and the wastewater treatment cost of the cleaning solution containing the Cl component is incurred.

In addition, when'calcium high content of nickel, cobalt and manganese hydroxide' with high calcium and manganese content is used as a raw material, calcium salt in the form of dihydrate gypsum (CaSO ₄ .2H ₂ O) is formed in the solvent extraction process under the influence of calcium. There is a problem that it cannot be applied to the production of high purity nickel sulfate (MHP) because the productivity is significantly lowered or the quality is adversely affected. Nickel, cobalt, and manganese hydroxide (MHP) have a very low nickel content of 20% and a high impurity content of nickel sulfate. There is a problem in that economic efficiency is deteriorated due to excessive manufacturing cost.

Therefore,'nickel containing calcium, cobalt, manganese sulfide (MSP, Mixed Sulfide Precipitation)' has a nickel content lower than nickel concentrate and nickel meth and higher nickel content than nickel, cobalt and manganese hydroxide (MHP). As 50%, it is necessary to develop a technology to economically manufacture high-purity nickel sulfate by using it as a raw material.

In addition, the calcium salt in the form of dihydrate gypsum (CaSO _4. 2H ₂ O) produced in the solvent extraction process under the influence of calcium contained in nickel, cobalt, and manganese sulfide acts as a factor of productivity and quality deterioration. For this, it is necessary to develop a technology that can effectively remove calcium salts.

KR 100981366 B1 (2010.09.03.) KR 101191042 B1 (2012.10.09.) KR 101412462 B1 (2014.06.20.) KR 101535250 B1 (2015.07.02.)

The present invention is to solve the above problems, and an object of the present invention is to provide a method of preparing a raw material slurry by applying one process without a mixing and washing process in the preparation of a raw material slurry of nickel, cobalt and manganese sulfide containing calcium. It is to do.

In addition, another object of the present invention is to provide a method of effectively ionizing metal components such as Ni, Co, and Mn, and controlling the removal of impurities other than metal components such as Ni, Co, and Mn to increase the efficiency and economy of the solvent extraction process. It is to do.

In addition, another object of the present invention is to effectively remove calcium salts in the form of dihydrate gypsum (CaSO ₄ .2H ₂ O) generated by using nickel, cobalt and manganese sulfide raw materials containing calcium, thereby improving the productivity and economy of nickel sulfate. It is to provide a method for producing high purity nickel sulfate with high and stable quality.

In addition, another object of the present invention is to provide an operating method capable of continuously and uniformly producing high-purity nickel sulfate crystals having an α-crystal structure of several mm in size from a purified aqueous nickel sulfate solution.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

In order to achieve the above object, the method of producing a high-purity nickel sulfate of the present invention comprises the steps of preparing a raw material slurry in a slurry reaction tank containing calcium-containing nickel, cobalt, and manganese mixed sulfide together with process water (S10); The raw material slurry is used in a two-stage pressurized heating reactor, and oxygen is added to react with the sulfur (S) component in the raw material to leach metal components such as nickel, cobalt, and manganese to generate sulfuric acid, and additionally add a pH adjuster. The step of obtaining an aqueous nickel sulfate solution (S20) in which a trace amount of a metal component in the raw material is generated as a hydroxide, precipitated, and filtered together with an insoluble component; After extracting the calcium (Ca) component from the aqueous nickel sulfate solution obtained in the step of obtaining the aqueous nickel sulfate solution using a solvent, dihydrate gypsum is precipitated after reacting with dihydrate gypsum (CaSO ₄ .2H ₂ O) in a mixing reactor. Removing step (S30); A solvent extraction method in which an aqueous nickel sulfate solution obtained after the dihydrate gypsum removal step is added to a multi stage mixed settler and nickel ions are extracted with an organic solvent using a solvent extractor, and nickel-containing organic obtained from the extraction process. A nickel sulfate purification method that removes impurity metals and extracts nickel by treating the solvent with an aqueous sulfuric acid solution in a mixed type settler and removing the washed nickel-containing organic solvent in a mixed type settler with an aqueous sulfuric acid solution. Liquid obtaining step (S40); And a nickel sulfate crystal seed is prepared from the nickel sulfate purification solution, and the nickel sulfate purification solution is added to a crystallization reactor (Crystallizer) to generate a crystal by heating, stirring, circulating and concentrating in a vacuum state to generate a high purity nickel sulfate crystal. Obtaining (S50); Includes.

In the step of obtaining the nickel sulfate purified liquid (S40), the zinc (Zn) component in the organic solvent is removed with an aqueous sulfuric acid solution at the intermediate extraction stage of the multistage mixing type settler before the nickel is finally removed by solvent stripping. Obtaining zinc (ZnSO ₄ ) (S41); Removing the cobalt (Co) component in the organic solvent with an aqueous sulfuric acid solution to incidentally obtain an aqueous cobalt sulfate solution (S42); It characterized in that it further comprises a step (S43) to obtain an aqueous manganese sulfate solution by removing the manganese (Mn) component in the organic solvent with an aqueous sulfuric acid solution.

In addition, the step of preparing the raw material slurry (S10) is characterized in that the flow rate is increased by pulverizing so that the particles of 100 μm or less are 80% or more using a pulverizer and sufficiently stirred with a stirrer.

In addition, in the step of obtaining the nickel sulfate aqueous solution (S20), oxygen is added to the first pressurized heating reactor to react with sulfide to generate metal ions and sulfuric acid (H ₂ SO ₄ ), and then impurity metals in the raw material are leached, By introducing an excessive amount of oxygen, the pressure in the reaction tank is maintained in the range of 11 to 15 bar, and the pH of the reaction tank is maintained in the range of 3 to 4 and the temperature is in the range of 150 to 180°C to extract metal ions from the raw material, and to prevent excessive temperature rise. The cooling water line of is installed inside the reaction tank, and oxygen is added to the secondary pressurized heating reaction tank so that iron (Fe) among the leached metal ions can be formed as hydrates and precipitated, so that the pressure of the reaction tank is maintained at 2 to 4 bar. The pH is maintained at 2 to 4, and steam or cooling water is added so that the temperature is in the range of 75 to 100°C.

In the step of removing the dihydrate gypsum (S30), a mixing reactor is used to increase the reactivity between the solvent extracted from calcium ions and the aqueous sulfuric acid solution, and the reacted dihydrate gypsum secures a residence time in the settling tank for 30 minutes or more. It is characterized by installing a separate cooling water line to maintain the temperature in the range of 20 ~ 30 ℃.

In addition, in the step of obtaining the nickel sulfate purification solution (S40), the driving temperature of the mixed settler is 20 to 50°C, the residence time of the nickel sulfate aqueous solution and the solvent extractant is 5 to 30 minutes, and the nickel sulfate aqueous solution and the solvent extracting agent are The volume ratio is characterized by controlling the size of the settling tank and the level of the solvent and the aqueous solution so that the volume ratio is 1: 1 ~ 1: 5, and the nickel sulfate purification step (S40) is performed when the solvent is extracted, the pH is 5.5 ~ 7.0, When washing the solvent, the pH is 4.0 to 5.0, and when the solvent is removed, the pH is 1.0 to 3.5.

In the step of obtaining zinc sulfate (S41), when the solvent is extracted, the pH is maintained at 2.5 to 3.0, when the solvent is washed, the pH is maintained at 1.5 to 2.5, and when the solvent is removed, the pH is maintained at 1.0 to 1.5, and the obtained aqueous zinc sulfate solution is precipitated. Then, the cake is discharged using a press filter, and in the step of obtaining an aqueous cobalt sulfate solution (S42), the pH is maintained at 4.5 to 6.0 when the solvent is extracted, and the pH is maintained at 4.0 to 4.5 when the solvent is washed. The aqueous solution of cobalt sulfate obtained by maintaining the pH of 2.0 to 3.0 when the solvent is removed is characterized in that the oil and impurities are removed and filtered in an active carbon column, and the step of obtaining the aqueous manganese sulfate solution (S43) is solvent extraction. When the solvent is cleaned, the pH is maintained between 4.5 and 6.0, and the pH is maintained between 4.0 and 4.5 when the solvent is removed, and the pH is maintained between 1.0 and 2.0 when the solvent is removed.The obtained aqueous manganese sulfide solution is removed from the active carbon column to remove oil and impurities. It is characterized by filtering.

In the step of obtaining the high-purity nickel sulfate crystal (S50), the crystallization reactor (Crystallizer) is maintained in a vacuum state at a pressure of -95 bar, and the temperature of the nickel sulfate purification solution is raised to 50°C to obtain a nickel sulfate crystal having an α-crystal structure. The nickel sulfate aqueous solution is continuously circulated to generate and grow crystals while maintaining stable vacuum and temperature conditions, and after transferring 10 to 15% of the circulation to the subsequent process, the aqueous solution is removed, washed with pure water, and dried. , High purity nickel sulfate hexahydrate having an α-crystal structure having an average size of 1.5 to 2.0 mm and a size distribution of 0.5 to 3 mm through a screening process is characterized.

The method for producing high-purity nickel sulfate prepared from a mixture of nickel, cobalt and manganese sulfides containing calcium according to the present invention includes counter current decantation, ball mill and filtering in the raw material slurry preparation step. The raw material slurry can be prepared simply through a single process without applying a cleaning method through a combination of or a mixed cleaning process of repulping and filtering.

In addition, when producing high-purity nickel sulfate using raw materials with a high calcium content and a nickel content of 40-50%, such as'nickel, cobalt, manganese sulfide' containing calcium, each reaction tank in a two-stage pressurized heating reactor By securing the appropriate pressure and temperature conditions separately, nickel metal is leached to obtain an aqueous nickel sulfate solution, and at the same time, trace metal ions of impurities are leached as hydroxide compounds and precipitated to remove insoluble substances together to increase the efficiency and economic efficiency of the leaching process. have.

In addition, a large amount of calcium (Ca) component contained in the raw material is reacted with an aqueous sulfuric acid solution using the mixing reactor according to the present invention to produce dihydrate gypsum (CaSO ₄ .2H ₂ O) and then settled in a settling tank, By removing it, it is possible to prevent clogging due to the formation of calcium salt in the piping and sedimentation tank in the solvent extraction process, and prevent contamination of the product and deterioration of purity due to calcium salt.

In addition, metal ions such as cobalt (Co), manganese (Mn), and zinc (Zn) contained in the raw material are precisely controlled by selecting an appropriate organic solvent and controlling the pH operating conditions in a multistage solvent extraction process. ), other than cobalt (Co), manganese (Mn), zinc (Zn), and other metals are expected to have an effect of maximizing the extraction amount, and the waste treatment cost of impurities can be reduced.

In addition, high-purity nickel sulfate hexahydrate with α-crystal structure can be uniformly prepared by an economical and efficient method, and nickel sulfate hexahydrate at a comparable level in physical properties and purity compared to commercially available nickel sulfate hydrate can be obtained. I can.

In addition, when the consumer uses it, it is easy to handle and dissolves in a relatively short time, so that the dissolution process time can be shortened, and the harmfulness to the human body caused by inhalation caused by the scattering of crystals can be minimized.

In addition, it is possible to minimize the use of organic solvents and discharge of wastewater.

1 is a flow chart of a manufacturing process of high purity nickel sulfate according to the present invention.
2 is a cross-sectional view of a mixing reactor for the dihydrate gypsum reaction according to the present invention.
3 is an electron micrograph of a nickel sulfate crystal having α and β-crystal structures, (a) is a nickel sulfate crystal having an α-crystal structure, and (b) is a nickel sulfate crystal having a β-crystal structure.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

With reference to the accompanying drawings below will be described in detail for the implementation of the present invention. Regardless of the drawings, the same reference numerals refer to the same elements, and "and/or" includes each and all combinations of one or more of the mentioned items.

The terms used in this specification are for describing exemplary embodiments, and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, “comprises” and/or “comprising” do not exclude the presence or addition of one or more other elements other than the mentioned elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the present invention will be described in more detail based on the accompanying drawings and preferred embodiments.

1 is a flow chart of a manufacturing process of high purity nickel sulfate according to the present invention.

Referring to Figure 1, first, in the slurry preparation step (S10) of calcium-containing nickel, cobalt, and manganese sulfide, a mixture of nickel, cobalt, and manganese sulfide containing calcium is added to a multistage slurry reaction tank to prepare a raw material slurry. Step. It is desirable to minimize the generation of wastewater by pulverizing the raw material so that the particle size of 100 μm or less is 80% or more using a pulverizer before the input of the raw material, and then introducing it into a multistage slurry reactor and recycling part of the process water of the leaching process. Do.

At this time, the input amount of the process water is controlled so that the concentration of the slurry is maintained in the range of 100 to 150 g/ℓ, and the size of the raw material particles in the slurry is preferably 100 μm or less. This is an important driving factor that improves the reaction and leaching efficiency in the leaching process step and minimizes the loss of raw materials in the solid-liquid separation process.Thus, three slurry reaction tanks were constructed to sufficiently dissolve the finely pulverized particles of 100 µm or more, and the primary slurry reaction tank It is preferable to move the raw material slurry of the supernatant completely dissolved in the second slurry reaction tank and the supernatant again to the third reaction tank to transfer the completely dissolved raw material slurry to the next step.

At this time, it is desirable to maintain the total residence time for more than 4 hours for complete dissolution of the raw material and to operate the rpm of the stirrer in the range of 90 to 100 so that the raw material particles are sufficiently dispersed in the slurry, and these operating conditions ensure the flow of the slurry Therefore, it is also advantageous to stably transfer the slurry to the leaching process. In addition, it is desirable to secure a sufficient residence time to maintain 90% or more of the raw material particle size of 100 μm or less.

High-concentration sulfuric acid (98%) is added to maintain the pH in the range of 3 to 4 to facilitate the dissolution of metal ions in the three slurry reactors. In this case, the heat of dilution of high-concentration sulfuric acid and the heat of reaction between sulfuric acid and metal ions are used. The raw material is dissolved by maintaining the temperature of the reaction tank in the range of 60 ~ 80 ℃. When the heat of dilution and heat of the high concentration sulfuric acid are insufficient, it is preferable to supply steam to the lower portion of the reaction tank to maintain the temperature of the reaction tank. At this time, the input amount of process water is controlled so that the raw material slurry concentration is maintained in the range of 100 ~ 150g/ℓ, and the process water is minimized wastewater generation by using a pressure filter filtrate of the leaching process.

At this time, since corrosion of the reaction tank may be caused by the influence of the chlorine (Cl) component and sulfuric acid contained in the raw material, the inside of the reaction tank is treated with rubber lining to extend the useful life of the facility.

The raw material slurry preparation step (S10) does not apply a cleaning method through counter current decantation, a combination of a ball mill and filtering, or a mixed cleaning process of repulping and filtering, Since the raw material slurry is prepared by maintaining the pH condition in the repulping reactor, the raw material slurry can be prepared simply through a single process.

The following is a step (S20) of obtaining a nickel sulfate leachate from a raw material slurry through a two-stage pressurized heating reactor. The raw material slurry is put into the first pressurized heating reaction tank, and oxygen is introduced into the lower part of the reaction tank to react with sulfides to generate metal ions and SO ₂ , and the generated SO ₂ is converted to SO ₃ under high pressure and high temperature conditions and reacts with water again. Sulfuric acid (H ₂ SO ₄ ) is produced.

The generated sulfuric acid leachs out the metals in the raw material and generates hydrogen gas, so to prevent explosion due to the generation of hydrogen gas and to increase the reaction efficiency between sulfide and oxygen, the pressure of the reaction tank is increased in the range of 11 to 15 bar by introducing an excessive amount of oxygen. Keep it as It is preferable to maintain the pH of the reactor in the range of 3 to 4 and the temperature in the range of 150 to 180°C, and a separate cooling water line is installed inside the reactor to prevent excessive temperature rise.

The nickel sulfate leachate from the first pressurized heating reaction tank is transferred to the second pressurized heating reaction tank, and oxygen is introduced so that iron (Fe) among the leached metal ions can be formed as hydrates and precipitated. At this time, the reaction tank is used to increase the hydration reaction efficiency. Oxygen is added to maintain the pressure in the range of 2 to 4 bar, and a pH adjuster is added to maintain the pH at 2 to 4, and steam or cooling water is preferably added so that the temperature is in the range of 75 to 100°C.

At this time, the precipitation reaction of impurities and trace metal ions in the pressurized heating reaction tank proceeds by 60 to 70% in the first pressurized heating reaction tank, and the rest is preferably carried out in the secondary pressurized heating reaction tank. The precipitate is transferred to a flash tank at the pressure of the reaction tank to discharge the steam, and then the temperature of the leachate is cooled to 40 ~ 50℃ using cooling water, and a press filter is placed in each of the reaction tanks of the two-stage pressure heating reaction tank. ) To discharge the sediment in the form of a cake.

In order to recover the precious metal component in the discharged sediment, it can be sold separately to a smelter to recover the precious metal component.

At this time, in order to increase the leaching efficiency in the pressurized heating reaction tank, the rpm of the stirrer is preferably maintained at 140 ~ 150 level and the residence time is maintained for at least 2 hours in each pressurized heating reaction tank, and the slurry of the leachate is It is preferable to maintain the concentration in the range of 50 to 100 g/ℓ.

In addition, since the pressurized heating reactor is operated at high pressure, the risk of explosion due to abnormal reactions inside the pressurized heating reactor is very high, so it is very important to keep the temperature and pressure of the pressurized heating reactor within the operating range, and to minimize adverse reactions. To prevent the risk of unexpected explosion by introducing oxygen (O ₂ ) into the pressurized heating reactor to aeration and reacting with hydrogen (H ₂ ) generated in the leaching reaction to generate water (H ₂ O) It is desirable to do.

In addition, in order to secure more process safety by establishing a facility that can supply a sufficient amount of cooling water, a hydrogen concentration meter is installed in the exhaust gas discharge pipe of the reaction tank to set an interlock or a safety valve. It is desirable to do.

The reaction occurring in the above-described step of obtaining an aqueous nickel sulfate solution (S20) is as follows.

(Equation 1) Leach reaction: MeS + O ₂ → Me + SO ₂

Here, Me refers to a metal component included in the raw material such as Ni, Co, Cu, Zn, Fe, and Al.

(Equation 2) Conversion reaction: SO ₂ + 0.5O ₂ → SO ₃

(Equation 3) Hydration reaction: SO ₃ + H ₂ O → H ₂ SO ₄

(Equation 4) Leaching reaction: Me + H ₂ SO ₄ → MeSO ₄ + H ₂

(Equation 5) Hydration reaction: 2H ₂ + O ₂ → 2H ₂ O

(Equation 6) Leaching reaction: Ni ₃ S ₂ + H ₂ SO ₄ + 0.5O ₂ → NiSO ₄ + 2NiS + H ₂ O

(Equation 7) Leaching reaction: (Ni.Fe) ₉ S ₈ + H ₂ SO ₄ + 16.5O ₂ → 9(Ni.Fe)SO ₄ + H ₂ O

(Equation 8) Hydroxide reaction: FeSO ₄ + 3H ₂ O + 0.5O ₂ → 2FeOOH + H ₂ SO ₄

(Equation 9) Hydroxide reaction: 2FeSO ₄ + 2H ₂ O + 0.5O ₂ → Fe ₂ O ₃ + H ₂ SO ₄

The following is a step of removing dihydrate gypsum (S30). More specifically, it is a step of reacting a large amount of calcium (Ca) component extracted in the solvent of an aqueous nickel sulfate solution obtained as above with an aqueous sulfuric acid solution to produce dihydrate gypsum (CaSO ₄ .2H ₂ O) and to remove the dihydrate gypsum after sedimentation. .

D2EPHA (Di- (2-ethylhexyl) phosphoric acid) using a solvent, calcium (Ca) and the solvent to extract the ions were charged into a mixing reactor (Reactor Mixing) is reacted with an aqueous solution of sulfuric acid at pH 1 ~ 2 range yisuseok and (CaSO ₄ After generating .2H ₂ O), remove after natural settling in the settling tank.

At this time, in order to increase the sedimentation efficiency, it is desirable to secure the residence time of the settling tank for at least 30 minutes, and to install a separate cooling water line so that the temperature of the leaching tank is maintained in the range of 20 ~ 30℃, and the precipitated gypsum is cleaned periodically. It is preferable to remove it by the method.

2 is a cross-sectional view of a mixing reactor for the dihydrate gypsum reaction according to the present invention. Referring to Figure 2 to explain the process of the dihydric gypsum reaction in the mixing reactor and the mixing reactor according to the present invention, the calcium extraction solvent containing calcium (Ca) ions is a calcium extraction solvent nozzle inside the reactor at a pressure of 6 ~ 7 bar After passing through (10), the aqueous sulfuric acid solution passes through the cylindrical porous sulfuric acid aqueous solution nozzle 20 at a pressure of 4 to 5 bar, and the dihydric gypsum reaction proceeds by mixing it orthogonally with the calcium extraction solvent in the reactor. At this time, the calcium extraction solvent Due to the large pressure of the ejector, the aqueous sulfuric acid solution is sucked into the hole of the aqueous sulfuric acid solution nozzle, and the dihydric gypsum reaction proceeds at the same time as mixing inside the reactor.To minimize the size of the reactor and increase the reaction efficiency, It is desirable to design a high fluid pressure difference.

Using the mixing reactor according to the present invention, a large amount of calcium (Ca) component contained in the raw material is reacted with an aqueous sulfuric acid solution to generate dihydrate gypsum (CaSO ₄ .2H ₂ O), and then settled and removed in a settling tank. In the solvent extraction process, it can prevent clogging caused by the formation of calcium salts in piping and sedimentation tanks, and prevent contamination of products and deterioration of purity due to calcium salts.

The following is a step (S40) of obtaining a purified nickel sulfate solution through a multistage mixing settler.

In more detail, the nickel sulfate aqueous solution obtained after the dihydrate gypsum removal step is subjected to solvent extraction, solvent scrubbing, and solvent stripping to remove metal ions in the leachate to obtain a nickel sulfate purified solution. Step.

A multi stage mixed settler is used to remove various kinds of metal ions, and as solvent extracting agents, D2EHPA (Di-(2-ethylhexyl) phosphoric acid), CYANEX272 (bis/2,4,4- trimethyl pentyl/ phosphinic acid), LIX84i (5-dodecylsalicylaldoxime and 2-hydroxy-5-nonylacetophenone oxime), Versatic10 (neodecanoic acid), etc., are diluted in a solvent such as ESCAID10 (Exxon Mobil Co.), KEROSENE (Nippon Petrochemical Co.), etc. Then, nickel ions and metal ions are extracted from the organic solvent, the size and quantity of the settling tank are selected according to the extraction amount of the metal ions and the purity of the product, and the optimum solvent extractant is applied for each metal ions, and the operation is adjusted according to the appropriate pH conditions. It is desirable to set the range.

At this time, the residence time in the settling tank is maintained for 5 ~ 30 minutes or more for each settling tank, and the flow rate is determined to maintain the height and quantity of the fence inside the settling tank to maintain 5 ~ 10 m/min, and the temperature inside the settling tank. It is preferable to adjust the water level of the settling tank so that it is maintained at 30 to 40°C and the volume ratio of the aqueous nickel sulfate solution and the solvent is 1:1 to 1:5.

In addition, the rpm of the stirrer is maintained in the range of 180 to 200 for sufficient agitation of the nickel sulfate aqueous solution and the solvent, and if the solvent is introduced into the nickel sulfuric acid crystallization process due to poor oil and water separation, the purity and marketability of the product are degraded. It is desirable to install a side glass in the settling tank so that the level of the aqueous nickel solution and solvent can be monitored at any time.

In the step of obtaining the nickel sulfate purification solution (S40), Versatic10 (neodecanoic acid) is used as a solvent extracting agent, and when the solvent is extracted, the pH is 5.5 to 7.0, when the solvent is washed, the pH is 4.0 to 5.0, and when the solvent is removed, the pH is 1.0 to 3.5. It is preferable to maintain, and in order to obtain a high-purity secondary nickel sulfate purification solution, the number of stages of the settling tank is preferably composed of at least 10 sets.

The step of obtaining the nickel sulfate purified solution (S40) is a step of extracting zinc sulfate (ZnSO ₄ ) from the intermediate extraction stage of a multistage mixing type settler before the nickel is finally stripped by solvent stripping (S41), an aqueous cobalt sulfate solution. It further includes the step of extracting (S42) and the step of extracting an aqueous manganese sulfate solution (S43).

In the step of extracting zinc sulfate (S41), D2EHPA (Di-(2-ethylhexyl) phosphoric acid) is used as a solvent extracting agent, and when the solvent is extracted, the pH is maintained between 2.5 and 3.0, and when the solvent is washed, the pH is maintained between 1.5 and 2.5. When the solvent is removed, the pH is maintained between 1.0 and 1.5, and the obtained zinc sulfate aqueous solution is filtered after removing oil and impurities in an active carbon column, forming a floc using a coagulant, and then press filter. It is discharged into the cake of zinc sulfate using (Pressure Filter).

In the step of extracting the aqueous cobalt sulfate solution (S42), CYANEX272 (bis/2,4,4-trimethyl pentyl/ phosphinic acid) is used as a solvent extracting agent, and the pH is maintained at 4.5 to 6.0 when the solvent is extracted, and the pH is maintained at the time of solvent washing. Maintains 4.0 ~ 4.5, pH is maintained at 2.0 ~ 3.0 when solvent is removed, and the obtained cobalt sulfate aqueous solution is sold as an aqueous solution after oil and impurities are removed in an active carbon column, filtered, and then sold.

In the step of extracting the aqueous manganese sulfate solution (S43), CYANEX272 (bis/2,4,4-trimethyl pentyl/ phosphinic acid) is used as a solvent extracting agent, and the pH is maintained at 4.5 to 6.0 when the solvent is extracted, and the pH is maintained at the time of solvent washing. The manganese sulfate aqueous solution obtained by maintaining 4.0 ~ 4.5 and maintaining the pH of 1.0 ~ 2.0 when the solvent is removed is sold as an aqueous solution after oil and impurities are removed in an active carbon column and filtered.

At this time, since cobalt ions are removed before manganese ions due to the characteristics of the solvent extracting agent, it is preferable to obtain an aqueous cobalt sulfate solution and an aqueous manganese sulfate solution in the first and last stages of the solvent stripping settlers of several stages, respectively.

In the present invention, metal ions such as cobalt (Co), manganese (Mn), and zinc (Zn) contained in raw materials are precisely controlled to select an appropriate organic solvent in a multi-stage solvent extraction process and to control the pH operation conditions, etc. The effect of maximizing the extraction amount of metals such as cobalt (Co), manganese (Mn), and zinc (Zn) other than Ni) is expected, and waste disposal costs of impurities can be reduced.

Finally, the step of obtaining high purity nickel sulfate hydrate of α-crystal structure by concentrated crystallization of the nickel sulfate purification solution through a crystallization reactor (S50). In more detail, the nickel sulfate purification solution obtained as described above is concentrated in a heated state in a vacuum crystallization reactor (Crystallizer) to generate nickel sulfate crystals to circulate the nickel sulfate purification solution to increase the size and amount of crystals to obtain high purity sulfuric acid. This is the step of obtaining nickel crystals, and the pressure of the crystallization reactor (Crystallizer) is maintained in a vacuum state of -95 to -97 bar, lowering the boiling point of the aqueous solution to 40℃ or less, and raising the temperature of the nickel sulfate purification liquid to 50℃ using a heat exchanger. Then, the moisture is evaporated, and the concentration of nickel sulfate is concentrated to 33 wt% or more to produce a nickel sulfate crystal having an α-crystal structure.

At this time, when the degree of vacuum is lowered, the boiling point rises and more heat sources must be supplied using a heat exchanger to generate the same amount of crystals. When the temperature of the nickel sulfate purification solution is raised to 50℃ or higher, a square α-crystal structure As it changes to a needle-shaped β-crystal structure, the size of the particles changes to fine particles, resulting in a decrease in production and deterioration in quality. Therefore, it is desirable to operate the vacuum degree and temperature within an appropriate range.

In addition, while maintaining stable vacuum and temperature conditions, the nickel sulfate aqueous solution should be continuously circulated to generate and grow crystals.If crystals of an appropriate size are formed, transfer 10 to 15% of the circulation amount to the subsequent process and screw Separating only nickel sulfate crystals in a type of solid-liquid separator (Thicker), washing impurities on the crystal surface with pure water, removing moisture in a centrifuge, drying in a hot air dryer, and then using a 0.5mm mesh network. Fine particles are removed in this installed sorter to prepare high purity nickel sulfate hydrate of α-crystal structure with an average diameter of 1.5 to 2.0 mm and a size distribution of 0.5 to 3 mm.

At this time, the nickel sulfate aqueous solution and fine particles generated from the solid-liquid separator (Thicker), the centrifuge, the cyclone after the hot air dryer, and the screen are collected in a storage tank of the nickel sulfate crystal mother liquid and crystallization reactor. It is re-introduced into the (Crystallizer) to play the role of a crystal seed, and impurities accumulated in the nickel sulfate crystal mother liquid storage tank flow into the final nickel sulfate crystal, and a certain amount of mother liquid is leached in order not to lower the purity. It is desirable to cycle through the process to remove accumulated impurities.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, provided that the following Examples are only examples of the present invention, and the scope of the present invention is not limited thereto.

In the present invention, a nickel-containing cathode material for a secondary battery manufactured using a nickel sulfate crystal manufactured by the above method, a nickel-containing precursor for manufacturing the cathode material, an industrial electroplating solution, and an electroless plating solution are also included. It includes a nickel-containing cathode material for batteries, a nickel-containing precursor for manufacturing the cathode material, an industrial electroplating solution, a secondary battery in which an electroless plating solution is used, a PCB substrate, a HDD storage disk, various electronic components, and various ornaments.

<< Example >>

A sample of nickel, cobalt, and manganese mixed sulfide (hereinafter referred to as Ni-Co-Mn MSP) containing calcium of the composition shown in Table 1 below is pulverized to a 10 kg sample, and the particles less than 100 μm are 85%, particles less than 75 μm. A sample having a particle size of 63% and 37 µm or less was prepared and placed in a reaction tank filled with 70 L of pure water, and the rpm of the stirrer was set to 100 and stirred for 2 hours. Soild concentration at this time was 128g/ℓ. After stirring, the slurry was filtered using a 100㎛ filter and the weight of the residue was measured. As a result, 443g. Particles less than 100㎛ in the slurry were 95.2%, and 10.2%p particles in the reaction tank. It was confirmed that it was dissolved to less than 100 μm.

Raw material composition table in Examples division Ni Al Ca Co Cu Fe Mg Mn Na Zn H ₂ O unit % % % % % % % % % % % (1) A 42.25 0.01 0.52 0.89 0.01 4.10 0.01 0.01 0.02 1.35 7.76

A: Composition of nickel, cobalt and manganese mixed sulfide containing calcium in Examples

The prepared raw material slurry was added to the reaction tank, the pH was set to 4.0, the temperature was maintained at 70°C, the rpm of the stirrer was set to 100, and the mixture was stirred for 4 hours. In the course of the implementation, it was confirmed that the temperature of the reaction tank increased and the pH decreased to 3.8 as time passed. This is because sulfur (S) in the raw material leached from the reaction tank, and the raw material and oxygen reacted to react with sulfuric acid, resulting in heat generation. It was determined that the pH decreased due to the influence of sulfuric acid.

The raw material slurry was introduced into a two-stage pressurized heating reaction tank (Autoclave), oxygen was gradually introduced at a flow rate of 2 L/min, and the pressure of the leaching tank was maintained at 14 bar, and the rpm of the stirrer was maintained at 150 and stirred for 4 hours. In the course of implementation, the temperature of the leaching tank was gradually increased to more than 170°C, and the pH was confirmed to be decreased to 3.1. The cooling water was sufficiently supplied to maintain the temperature of the leaching tank at 165°C. It was determined that the temperature increase in the leaching tank was raised by the reaction heat of sulfur (S) and oxygen in the leaching tank.

After cooling the nickel sulfate leachate to 40°C, the precipitate was removed using a centrifugal dehydrator, and then added to the same pressurized heating reactor to perform a hydroxylation reaction under different operating conditions, and caustic soda (NaOH) 0.8 L was added to the pH of the reactor. After setting the value to 3.5, oxygen was slowly added at a flow rate of 0.3ℓ/min, while maintaining the pressure of the leaching tank at 3.5bar, maintaining the rpm of the stirrer at 150, and heating the leaching tank to maintain 90℃ and stirred for 2 hours. And, it was confirmed that the temperature of the leaching tank gradually increased to 70°C during the implementation process. The temperature was raised and maintained at 90°C in order to secure an appropriate leaching condition of 90°C, and at this time, the composition of the final aqueous nickel sulfate solution is shown in Table 2.

Composition of aqueous nickel sulfate solution in a pressurized heating reactor in Examples (based on buildings) division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % % % % % % % % % % (1) B 93.87 ND 1.08 1.98 0.02 0.09 0.02 0.02 0.04 2.88

B: The component value of the nickel sulfate leachate in the pressurized heating reactor

The result of confirming the composition of the precipitate obtained by using a centrifugal dehydrator after cooling the nickel sulfate leachate to 50°C is shown in Table 3, and the total amount of the precipitate was 0.59 kg, which was 6.4% of the raw material based on dry matter. It was confirmed that on and insoluble substances were removed and 82% of aluminum was removed, and it was confirmed that the amount of precipitation in the first pressurized heating reactor was 65% and that in the second pressurized heating reactor was 35%.

Composition of leachate in the first and second pressurized heating reactors in Examples (based on buildings) division Ni Al Ca Co Cu Fe Mg Mn Na Zn Solid unit % % % % % % % % % % % (1) C 2.37 0.18 0.87 0.04 ND 74.64 ND 0.02 ND 1.13 20.74 (2) D 2.23 0.09 0.33 0.02 ND 73.42 ND 0.03 0.02 0.96 22.90 (3) E 2.32 0.15 0.68 0.03 ND 74.22 ND 0.02 0.01 1.07 21.49 (4) F 0.30 82.00 7.20 0.20 ND 99.00 ND 13.00 1.80 4.35 100.0

C: Dehydration cake component value of nickel sulfate leachate in the first pressurized heated leaching tank

D: Dehydration Cake Components of Nickel Sulfate Leachate in the Secondary Pressurized Heating Leach

E: Component value for the total amount of 1st and 2nd dehydration cake

F: Metal ion removal rate before and after inputting the pressurized heating cabinet

After cooling the above aqueous nickel sulfate solution to 30° C., it was added to a settling tank with a mixing reactor to check the gypsum removal efficiency. First, the nickel sulfate aqueous solution and D2EPHA (Di-(2-ethylhexyl)phosphoric acid) solvent were mixed and stirred for 10 minutes at pH 3.0 condition, and then the solvent from which calcium ions were extracted and the aqueous sulfuric acid solution were added to a mixing reactor. , So that the pH inside the reactor was 2.0, aqueous sulfuric acid was added to react with dihydrate gypsum (CaSO ₄ .2H ₂ O), and then settled for 30 minutes in a settling tank.

At this time, in order to increase the sedimentation efficiency of the dihydrate gypsum in the settling tank, the flow rate was maintained at 5 m/min, and it was confirmed that the dihydrate gypsum crystals settled at the bottom of the settling tank. , The removal efficiency of calcium was confirmed to be 85.0%, and it was confirmed that a small amount of components such as zinc, manganese, and copper other than calcium were precipitated.

Composition of aqueous nickel sulfate solution before and after the mixing reactor in Examples (based on building) division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % % % % % % % % % % (1) G 93.87 ND 1.08 1.98 0.02 0.09 0.02 0.02 0.04 2.88 (2) H 95.29 ND 0.16 2.01 0.02 0.09 0.02 0.00 0.04 2.35 (3) I 0 ND 85.0 0 9.3 0 2.9 80.5 0 19.7

G: The component value of the nickel sulfate leachate before inputting the mixing reactor

H: The component value of the nickel sulfate leachate after inputting the mixing reactor

I: Metal ion removal rate before and after inputting the mixing reactor

In order to remove calcium and zinc ions from the solvent after removing the gypsum, an aqueous sulfuric acid solution was added to maintain the temperature at 40℃ under the condition of pH 1.0, and a solvent cleaning process and a solvent stripping process were performed for 20 minutes with a three-stage settling tank. The aqueous zinc sulfate solution containing dihydrate gypsum obtained in the process was obtained in the form of a cake using a centrifuge. As a result of analyzing the components of the cake, it was found that 93.0% of calcium ions and 100% of zinc ions were removed.

In order to remove manganese ions and cobalt ions from the nickel sulfate aqueous solution obtained in the solvent washing process, an aqueous solution was added to the 8-stage mixed settler using CYANEX272 (bis/2,4,4-trimethyl pentyl/ phosphinic acid) solvent. At this time, an aqueous solution of cobalt sulfate obtained by performing the solvent extraction process while maintaining the pH 5.0 to 5.5 with an aqueous NaOH solution, performing the solvent washing process while maintaining the pH 4.5, and performing the solvent stripping process under the conditions of pH 1.0 to 3.0 with an aqueous sulfuric acid solution. As a result of analyzing the components of the aqueous manganese sulfate solution, it was confirmed that 59.1% of manganese ions and 98.4% of cobalt ions were removed.

In order to remove trace amounts of metal ions from the nickel sulfate aqueous solution that has been subjected to the solvent washing process and to obtain a high purity nickel sulfate purification solution, Versatic10 (neodecanoic acid) was added to the 11th stage mixed settling tank. The solvent extraction process was performed under the conditions of 5.5 to 7.0, the solvent washing process was performed under the conditions of pH 5.0 with an aqueous sulfuric acid solution, and the solvent stripping process was performed under the conditions of pH 1.0 to 3.0 with an aqueous sulfuric acid solution to obtain a high purity nickel sulfate purified solution. The purity of nickel ion was confirmed to be 99.99%.

Table 5 shows the analysis results of the cake and high-purity nickel sulfate purification solution obtained after passing through the multistage mixing settler process.

Composition of Cake, zinc, cobalt, manganese extract, and high-purity nickel sulfate tablet liquid obtained after going through the process of a multi-stage mixing settler in Examples (based on buildings) division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % % % % % % % % % % (1) J ND ND 5.8 ND 0.3 3.5 0.6 0.1 ND 89.8 (2) K ND 0.2 0.2 98.6 0.7 ND 0.3 0.1 ND ND (3) L 99.99 ND 0.0036 0.001 ND ND 0.001 0.001 0.001 ND

J: Ingredient value of zinc sulfate dehydrated cake

K: component values of aqueous solution of cobalt sulfate and manganese sulfate

L: Component value of nickel sulfate purification solution from which metal ions have been removed

It was confirmed that crystals were formed as a result of heating and stirring the high purity nickel sulfate purification solution obtained as above in a vacuum state of -91 bar using a vacuum pump at -91 bar, and the nickel sulfate purification solution evaporated at 45°C. If the vacuum state is maintained above -95bar, it was determined that the boiling point of the purified liquid was lowered to 35°C and more crystals could be formed.

The nickel sulfate crystal obtained as described above was washed with pure water and dried using a centrifugal dehydrator and a dry oven, and the result of analyzing the grain size of the crystal is shown in Table 6. As a result of confirming the crystal with an electron microscope, it has a square α-crystal structure. It was confirmed and the composition of the crystal is shown in Table 6 below.

Composition of nickel sulfate crystals in the examples (based on buildings) division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ (1) M 22.3 ND 8 2 ND ND One 2 2 ND

M: component value of nickel sulfate crystal

《Comparative Example 1》

Although the process of obtaining nickel sulfate crystals was performed in the same manner as in the examples without using the mixing reactor of the examples, it was confirmed that calcium salts were formed inside the sedimentation tank and in the piping in the solvent extraction process, and after generating the crystals, ICP-OES As a result of analyzing the chemical composition by (Inductively Coupled Plasma-Optical Emission Spectroscopy), the Ca content was found to be 54 mg/ℓ, indicating that unlike the present invention, calcium was not sufficiently removed, and the analysis result is shown in Table 7 below. .

Composition of nickel sulfate crystals obtained without using a mixed reactor (based on buildings) division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ (1) N 22.29 ND 54 2 ND ND One 8 2 ND

N: component value of nickel sulfate crystal obtained without using a mixed reactor

《Comparative Example 2》

In the same manufacturing method as in the above example, the temperature was gradually raised to 60°C in the step of obtaining high-purity nickel sulfate crystals of α-crystal structure, and as a result of generating nickel sulfate crystals, a square α-crystal structure was formed up to 52°C. However, it was confirmed that the square crystal structure was broken as it exceeded 52°C, and the crystal structure was changed to a needle-like β-crystal structure in the form of fine particles.

"evaluation"

As in the examples, it was confirmed that high-purity nickel sulfate can be produced by using nickel, cobalt and manganese sulfide containing calcium as raw materials. In particular, calcium is effectively removed by using a mixing reactor. It was confirmed in Table 7 of Comparative Example 1 that the present invention is effective in reducing productivity and improving purity of nickel sulphate crystals and reducing impurities due to calcium salt formation in the extraction process.

In order to evaluate the nickel sulfate crystal obtained in the comparative example, the result of comparison with the product of Norilsk, Finland, the largest manufacturer of nickel sulfate, is shown in Table 8, and it was confirmed that the purity of the nickel sulfate of the example was at the same level compared to the product of Norilsk.

Examples and results of analysis of nickel sulfate crystals of commercial products division Ni Al Ca Co Cu Fe Mg Mn Na Zn unit % Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ Mg/ℓ (1) O 22.3 ND 8 2 ND ND One 2 2 ND (2) P 22.3 <5 <20 <5 <5 <5 <15 <5 <20 <5

O: component value of the nickel sulfate crystal of the example

P: Ingredient value of Norilsk's nickel sulfate product

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features. You can understand that there is. Therefore, it is to be understood that the embodiments described above are illustrative in all respects and not limiting.

10: calcium extraction solvent nozzle
20: sulfuric acid aqueous solution nozzle

Claims (10)

In the method for producing a high purity nickel sulfate prepared from a calcium-containing nickel, cobalt and manganese mixed sulfide raw material,
The mixed sulfide of nickel, cobalt and manganese containing calcium is pulverized so that the particle size of 100㎛ or less is 80% or more using a grinder, and the process water and the pulverized mixed sulfide are sufficiently stirred with a stirrer in the reaction tank to increase the flow rate Preparing step (S10);
The raw material slurry is used in a two-stage pressurized heating reactor, and oxygen is added to react with the sulfur (S) component in the raw material to leach metal components such as nickel, cobalt, and manganese to generate sulfuric acid, and a pH adjuster is added. A step (S20) of obtaining an aqueous nickel sulfate solution in which a trace amount of a metal component in the raw material is produced as a hydroxide, and a precipitation reaction is carried out by adding it to filter it together with an insoluble component;
After extracting the calcium (Ca) component using a solvent in the aqueous nickel sulfate solution obtained in the step of obtaining the aqueous nickel sulfate solution, dihydrate gypsum is precipitated after reacting with dihydrate gypsum (CaSO ₄ .2H ₂ O) in a mixing reactor. Removing step (S30);
A solvent extraction method in which an aqueous nickel sulfate solution obtained after the dihydrate gypsum removal step is added to a multi stage mixed settler and nickel ions are extracted with an organic solvent using a solvent extractor, and nickel-containing organic obtained from the extraction process. A nickel sulfate purification method that removes impurity metals and extracts nickel by treating the solvent with an aqueous sulfuric acid solution in a mixed type settler, and removing the washed nickel-containing organic solvent in a mixed type settler with an aqueous sulfuric acid solution. Liquid obtaining step (S40); And
A nickel sulfate crystal seed is prepared from the nickel sulfate purification solution, and the nickel sulfate purification solution is added to a crystallization reactor, heated in a vacuum state, stirred, circulated, and concentrated to generate crystals to obtain a high purity nickel sulfate crystal. Obtaining step (S50);
Method for producing high-purity nickel sulfate prepared from a mixed sulfide raw material containing nickel, cobalt, and manganese containing calcium, comprising a. The method of claim 1,
In the step of obtaining the nickel sulfate purified liquid (S40), the zinc (Zn) component in the organic solvent is removed with an aqueous sulfuric acid solution at the intermediate extraction stage of the multistage mixing type settler before the nickel is finally removed by solvent stripping. Zinc sulfate (ZnSO ₄ ) obtaining step (S41);
Removing the cobalt (Co) component in the organic solvent with an aqueous sulfuric acid solution to incidentally obtain an aqueous cobalt sulfate solution (S42);
Removing the manganese (Mn) component in the organic solvent with an aqueous sulfuric acid solution to incidentally obtain an aqueous manganese sulfate solution (S43);
Method for producing high purity nickel sulfate prepared from a mixed sulfide raw material containing nickel, cobalt and manganese containing calcium, characterized in that it further comprises. delete The method of claim 1,
The step of obtaining the nickel sulfate aqueous solution (S20)
In the primary pressurized heating reactor, oxygen is added to react with sulfide to generate metal ions and sulfuric acid (H ₂ SO ₄ ), and then impurity metals in the raw material are leached, and the pressure of the reactor is increased in the range of 11 to 15 bar by introducing an excessive amount of oxygen. And maintain the pH of the reaction tank in the range of 3~4 and the temperature in the range of 150~180℃ to extract metal ions from the raw material, and install a separate cooling water line inside the reaction tank to prevent excessive temperature rise.
In the secondary pressurized heating reaction tank, oxygen is introduced to form iron (Fe) among the leached metal ions as hydrates and precipitate, so that the pressure of the reaction tank is maintained at 2-4 bar, and the pH is maintained at 2-4. A method for producing high-purity nickel sulfate prepared from a mixture of calcium-containing nickel, cobalt, and manganese sulfide, characterized in that steam or cooling water is added so that the temperature is in the range of 75 to 100°C. The method of claim 1,
The step of removing the dihydrate gypsum (S30) is
A mixing reactor is used to increase the reactivity between the solvent extracted from calcium ions and the aqueous sulfuric acid solution.
The reacted dihydrate gypsum is a calcium-containing nickel, cobalt, and manganese mixed sulfide raw material, characterized in that a separate cooling water line is installed to secure the residence time in the settling tank for more than 30 minutes and to maintain the temperature in the range of 20 ~ 30℃. Method for producing high purity nickel sulfate to be produced. The method of claim 1,
The nickel sulfate purification step (S40) is
The driving temperature of the mixed settler is 20 ~ 50℃, the residence time of the nickel sulfate aqueous solution and the solvent extractant is 5 ~ 30 minutes, and the volume ratio of the nickel sulfate aqueous solution and the solvent extractant is 1: 1 ~ 1: 5 Adjust the size of the highlight and the level of the solvent and aqueous solution,
When the solvent is extracted, the pH is 5.5 to 7.0, when the solvent is washed, the pH is 4.0 to 5.0, and when the solvent is removed, the pH is 1.0 to 3.5. This is a high purity nickel sulfate prepared from a mixture of calcium-containing nickel, cobalt, and manganese sulfide. Manufacturing method. The method of claim 2,
The zinc sulfate obtaining step (S41)
When the solvent is extracted, the pH is maintained between 2.5 and 3.0, when the solvent is washed, the pH is maintained between 1.5 and 2.5, and when the solvent is removed, the pH is maintained between 1.0 and 1.5.
The obtained zinc sulfate aqueous solution is precipitated and then discharged to the cake using a press filter. A method for producing high-purity nickel sulfate prepared from a mixed sulfide raw material containing nickel, cobalt and manganese containing calcium. The method of claim 2,
The step of obtaining the aqueous cobalt sulfate solution (S42)
When the solvent is extracted, the pH is maintained at 4.5 ~ 6.0, the pH is maintained at 4.0 ~ 4.5 when the solvent is removed, and when the solvent is removed, the pH is maintained at 2.0 ~ 3.0. The resulting aqueous solution of cobalt sulfate removes oil and impurities in an active carbon column. A method for producing high-purity nickel sulfate prepared from a mixed sulfide raw material containing nickel, cobalt, and manganese containing calcium, comprising removing and filtering. The method of claim 2,
In the step of obtaining an aqueous manganese sulfate solution (S43), the pH of the manganese sulfate aqueous solution is maintained at 4.5 to 6.0 when the solvent is extracted, the pH is 4.0 to 4.5 when the solvent is washed, and the pH is 1.0 to 2.0 when the solvent is removed. A method for producing high-purity nickel sulfate prepared from a mixture of nickel, cobalt and manganese sulfides containing calcium, characterized in that oil and impurities are removed and filtered in (Active Carbon Column). The method of claim 1,
The step (S50) of obtaining the high purity nickel sulfate crystal
The crystallization reactor (Crystallizer) is maintained in a vacuum state at a pressure of -95 bar, and the temperature of the nickel sulfate purification solution is raised to 50°C to produce a nickel sulfate crystal of α-crystal structure,
While maintaining stable vacuum and temperature conditions, the nickel sulfate aqueous solution is continuously circulated to generate and grow crystals, and after transferring 10 to 15% of the circulating amount to the subsequent process, the aqueous solution is removed and washed with pure water, drying, and sorting process. High purity prepared from a nickel, cobalt and manganese mixed sulfide raw material containing calcium, characterized in that high purity nickel sulfate hexahydrate having an α-crystal structure having an average size of 1.5 to 2.0 mm and a size distribution of 0.5 to 3 mm is prepared Method for producing nickel sulfate.

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