CN116216798A - A kind of method utilizing nickel hydroxide cobalt to prepare battery grade nickel sulfate - Google Patents

Abstract

The invention relates to a method for preparing battery grade nickel sulfate by using cobalt nickel hydroxide, which comprises the following steps: pre-leaching after pulping cobalt nickel hydroxide to obtain pre-leaching liquid; carrying out first solid-liquid separation on the obtained pre-leaching solution after first-stage dissolution to obtain insoluble slag and first-stage dissolution solution; pulping the insoluble slag and performing two-stage dissolution to obtain a two-stage dissolution solution; the reducing agent used for the second-stage dissolution is ferrous sulfate; oxidizing the dissolution solution by using high-valence manganese slag as an oxidant to obtain an oxidation solution; then sequentially carrying out iron precipitation and silicon removal, second solid-liquid separation, pH value adjustment, extraction, oil removal and phosphorus removal and third solid-liquid separation to obtain battery grade nickel sulfate; the high-valence manganese slag is obtained by post-treatment of copper-manganese liquid obtained by extraction; the method can shorten the leaching time, improve the leaching efficiency, reduce the use of dangerous chemicals, avoid the generation of sulfur dioxide and the use of sodium chlorate from the source, reduce the safety and environmental protection risks and realize the safe and environmental protection production from the source.

Description

A kind of method utilizing nickel hydroxide cobalt to prepare battery grade nickel sulfate

technical field

The invention belongs to the technical field of metallurgy and relates to a method for utilizing nickel-cobalt hydroxide, in particular to a method for preparing battery-grade nickel sulfate by utilizing nickel-cobalt hydroxide.

Background technique

Due to the depletion of sulfide nickel ore resources, laterite nickel ore has become the main resource of nickel raw materials due to its large reserves and easy mining. Nickel hydroxide and cobalt raw materials produced by the transformation of laterite nickel ore are gradually becoming the main raw materials for nickel salt production enterprises to produce nickel salt products because the price is lower than that of nickel raw materials produced by nickel sulfide ore.

The production of battery-grade nickel sulfate by using nickel and cobalt hydroxide mostly adopts hydrometallurgical process, and its process generally includes processes such as sulfuric acid leaching, neutralization and removal of iron and aluminum, extraction and removal of impurities, and separation of nickel and cobalt. Due to the complex composition of nickel cobalt hydroxide and the extremely strict requirements on impurities in battery-grade nickel sulfate, hazardous chemicals are often used in the production process, or there is a problem of low production efficiency.

For example, CN111455174A discloses a method for preparing battery-grade nickel sulfate and cobalt sulfate from mixed nickel hydroxide and cobalt. It uses sulfuric acid to leach mixed nickel and cobalt hydroxide, and then uses nickel/cobalt/manganese-based neutralizer to remove iron and aluminum in the solution, liquid-solid separation to obtain iron removal slag, acid-dissolved recovery of nickel and cobalt, after iron removal, the liquid is added to the precipitant removal system Calcium and magnesium ions in. After the removal of calcium and magnesium, the P204 extractant after saponification is used to remove impurities such as Mn, Zn, Cu, etc., and the P204 raffinate is separated from nickel and cobalt by the P507 extractant after saponification to obtain battery-grade nickel sulfate and cobalt sulfate solutions, which are obtained by evaporation and crystallization. product.

CN111826523A discloses a method for refining nickel-cobalt hydroxide. It makes slurry of nickel-cobalt hydroxide, raises the temperature, then adds acid solution to adjust pH value, reacts, and obtains prepreg slurry; adds acid solution to prepreg slurry to adjust pH value, then add sulfur dioxide, react, and obtain the reducing acid immersion solution; add the alkali slurry to the reducing acid immersion solution to adjust the pH, pass into the oxidizing gas, react, and press filter to obtain the first filtrate and the first filter residue; Add the solution to part of the first filtrate to adjust the pH, react to obtain a nickel carbonate solution, and press filter to obtain nickel carbonate and nickel-precipitated liquid; add nickel carbonate to part of the first filtrate to obtain a nickel carbonate slurry; The filtrate is aged and finely filtered to obtain the first filtrate and the second filter residue, and the filtrate is taken for the second fine filtration to obtain a nickel sulfate solution.

CN112210679A discloses a method for preparing nickel sulfate from nickel-cobalt hydroxide. Nickel-cobalt hydroxide contains impurities manganese, iron, scandium, aluminum and chromium. Reductive acid leaching is carried out under the following conditions to obtain a leach solution; S2, adding a catalyst, an oxidizing agent and a neutralizing agent to the leach solution to simultaneously carry out a catalytic oxidation reaction and a neutralization reaction to obtain the first impurity removal solution; S3, the first impurity removal solution Perform extraction to remove impurities, evaporate and crystallize to obtain nickel sulfate.

Although the above-mentioned prior art can utilize nickel hydroxide and cobalt to prepare battery-grade nickel sulfate, there are generally the following problems: pyrosub-reduction insoluble slag is added during the dissolution process, and the addition of pyrosulfate and sulfuric acid is large, and the dissolution rate is slow, affecting The leaching efficiency of the whole process will also produce a large amount of sulfur dioxide gas; in addition, a large amount of acid-insoluble slag will be generated during the dissolution process, and this part of the acid-insoluble slag that cannot be completely reduced will enter the iron slag, which will affect the processing difficulty of the iron slag. Increase the amount of washing slag water to cause water expansion; and the acid-insoluble slag is high-priced cobalt-nickel slag such as hydroxynickel hydroxycobalt, and this part of cobalt nickel enters the slag, causing the loss of nickel and cobalt; in addition, the oxidant used in the conventional prior art is chlorine Hazardous chemicals such as sodium bicarbonate or hydrogen peroxide, the cost of storage and use is relatively high.

Therefore, aiming at the defects in the prior art, it is necessary to provide a method for preparing battery-grade nickel sulfate by using nickel cobalt hydroxide.

Contents of the invention

The object of the present invention is to provide a kind of method utilizing nickel hydroxide cobalt to prepare battery-grade nickel sulfate, and described method can shorten leaching time, improves leaching efficiency; And described method can avoid the generation of sulfur dioxide and sodium chlorate from the source The use reduces safety risks; moreover, the method can eliminate the use of additional hazardous chemicals, reduce safety risks and environmental protection pressure, improve the working environment quality of operators, and essentially realize safe and environmentally friendly production.

To achieve this purpose of the invention, the present invention adopts the following technical solutions:

The present invention provides a kind of method utilizing nickel hydroxide cobalt to prepare battery-grade nickel sulfate, and described method comprises the following steps:

(1) carry out preleaching after nickel cobalt hydroxide pulping, obtain prepreg;

(2) The prepreg obtained in step (1) is subjected to the first solid-liquid separation after one stage of dissolution to obtain insoluble slag and one stage of solution;

(3) Step (2) gained insoluble slag is through pulping and two-stage dissolving, obtains two-stage dissolving liquid; The used reducing agent of described two-stage dissolving is ferrous sulfate;

(4) Use high-valent manganese slag as an oxidizing agent to oxidize a section of the dissolved solution obtained in step (2) to obtain an oxidized solution; Three solid-liquid separations to obtain battery-grade nickel sulfate;

The high-priced manganese slag described in step (4) is obtained after processing the copper-manganese liquid obtained through extraction;

Step (3) and step (4) are in no particular order.

The method provided by the invention adopts the technical scheme of segmental leaching, which shortens the leaching time and improves the leaching efficiency. Moreover, the method provided by the present invention uses ferrous sulfate as a reducing agent during the second stage of dissolution, avoiding the generation of sulfur dioxide from the source, reducing safety risks and environmental risks; in addition, the copper-manganese liquid produced in the extraction process is used as raw material to prepare High-priced manganese slag avoids the use of sodium chlorate, which also reduces safety risks, and does not require externally purchased oxidants, saving production costs.

The "high-valent manganese slag" mentioned in the present invention refers to oxidizable ferrous sulfate manganese slag formed after manganese hydroxide is oxidized, and its main component is MnO(OH).

Preferably, the solid-to-liquid ratio of pulping in step (1) is 1:(3-5), such as 1:3, 1:3.5, 1:4, 1:4.5 or 1:5 but not limited to The enumerated numerical values, other unenumerated numerical values within the numerical range are also applicable, and the unit of the solid-liquid ratio is g/L.

Exemplarily, the preleaching in step (1) of the present invention is carried out using sulfuric acid with a concentration above 90wt%.

Preferably, the pre-leaching temperature in step (1) is 70-80°C, for example, it can be 70°C, 72°C, 75°C, 78°C or 80°C, but it is not limited to the listed values, and other values within the range are not The listed values also apply.

Preferably, the pH value of the pre-leaching in step (1) is 3-4, such as 3, 3.2, 3.5, 3.8 or 4, but not limited to the listed values, other unlisted values within the range of values are also applicable .

Exemplarily, the first stage of dissolution in step (2) is carried out using sulfuric acid with a concentration above 90wt%.

Preferably, the melting temperature in step (2) is 70-80°C, for example, it can be 70°C, 72°C, 75°C, 78°C or 80°C, but it is not limited to the listed values. The listed values also apply.

Preferably, the pH value of the stage of dissolution in step (2) is 1-1.5, such as 1, 1.2 or 1.5, but not limited to the listed values, other unlisted values within the range of values are also applicable.

The main components of the insoluble slag obtained in the step (2) of the present invention are cobalt oxyhydroxide and nickel oxyhydroxide.

Preferably, the slurrying described in step (3) is slurrying using sulfuric acid, and the solid-to-liquid ratio of slurrying is (1-2):1, for example, it can be 1:1, 1.2:1, 1.5:1, 1.8: 1 or 2:1, but not limited to the listed values, other unlisted values within the range of values are also applicable, and the unit of the solid-liquid ratio is g/L.

In the slurrying described in step (3) of the present invention, water is firstly used as the bottom liquid, and then insoluble slag and sulfuric acid are added in sequence. The solid-to-liquid ratio of slurrying refers to the solid-to-liquid ratio of insoluble slag to sulfuric acid.

The quality of the water is generally 1-2 times the quality of the insoluble slag, and the present invention does not make too many limitations here, as long as the mass concentration of sulfuric acid during slurrying meets the process requirements.

Preferably, during the slurrying described in step (3), the mass concentration of sulfuric acid ≥ 35g/L, such as 35g/L, 40g/L, 50g/L, 60g/L, 80g/L or 100g/L, but Not limited to the numerical values listed, other unlisted numerical values within the numerical range are also applicable.

Preferably, the temperature of the second-stage dissolution in step (3) is 70-80°C, for example, it can be 70°C, 72°C, 75°C, 78°C or 80°C, but it is not limited to the listed values, and other values within the range are not The listed values also apply.

Preferably, the second-stage dissolution time in step (3) is ≤30 minutes, for example, it can be 10 minutes, 15 minutes, 20 minutes, 25 minutes or 30 minutes, but it is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

The reducing agent ferrous sulfate is added in the second-stage dissolution process of the present invention, and the reduction end point is that the suspension is clear and bright without insoluble impurities.

The main components of the insoluble slag obtained from the first stage of dissolution in the present invention are cobalt hydroxy and nickel hydroxy, which belong to high-valence cobalt nickel. The conventional production process performs reduction in an environment where the pH of the slurry is 1-1.5, and this condition requires the addition of more reducing agents. , and takes a long time. Taking a ^20m3 slurry as an example, the conventional process requires more than 4 hours of reduction time, and complete reduction cannot be achieved, which is not conducive to continuous and stable production. If the acidity of the slurry is simply adjusted, a large amount of acid will be consumed, which is not conducive to subsequent processing.

The present invention adopts the technical scheme of one-stage dissolution, first solid-liquid separation and two-stage dissolution, and reacts hydroxycobalt and nickel hydroxylation under medium-high acidity conditions, which saves the amount of reducing agent added, and greatly shortens the reaction time, which is beneficial to Promote continuous and stable production, greatly saving time and pharmaceutical costs.

The reducing agent used in the second-stage dissolution of the present invention is ferrous sulfate. Conventional reducing agents in the art include sodium metabisulfite, sodium sulfite, sulfur dioxide, sodium sulfide or hydrogen peroxide. Among them, the use of sodium metabisulfite, sodium sulfite and sulfur dioxide will inevitably produce sulfur dioxide, which has a strong pungent taste; while sodium sulfide will generate highly toxic hydrogen sulfide under acidic conditions, and the pH value needs to be adjusted to above 4 before it can be used normally ; Hydrogen peroxide will produce bubbles, which will easily lead to the phenomenon of sinking, which is not conducive to control. However, the use of ferrous sulfate in this application avoids the generation of sulfur dioxide, and eliminates pollution sources and danger sources from the source; moreover, the present invention uses ferrous sulfate to act as a reducing agent in the second-stage dissolution, which is equivalent to supplementing the front end of sinking iron and removing silicon. iron, saving the amount of ferric iron for subsequent supplementation.

In the present invention, the quality of the reductant ferrous sulfate used in the second-stage dissolution is 10-30% of the insoluble slag, for example, it can be 10%, 15%, 20%, 25% or 30%, but it is not limited to the listed values , other unlisted values within the value range are also applicable.

Preferably, the preparation method of the high-priced manganese slag described in step (4) comprises the following steps:

The pH value of the copper-manganese solution is adjusted to 6-6.5; after filtration, the pH value is adjusted to 9-9.5 under the condition of feeding oxygen-containing gas, and high-priced manganese slag is obtained by solid-liquid separation.

The present invention adjusts the pH value of the copper-manganese solution by adding alkali to 6-6.5, and can remove more than 99% of copper and zinc; then continues to add alkali to adjust the pH value to 9-9.5, so that the manganese is precipitated, and the manganese hydroxide produced in the precipitation process It will be quickly oxidized by air into high-valent manganese slag, the reaction equation of this process is:

4Mn(OH) ₂ +O ₂ =4MnO(OH)+2H ₂ O;

When the present invention utilizes copper-manganese liquid to prepare high-priced manganese slag, the first adjusted pH value is 6-6.5, such as 6, 6.2 or 6.5, but it is not limited to the listed values, and other unlisted values within the range of values are also applicable.

When the present invention utilizes copper-manganese liquid to prepare high-priced manganese slag, the pH value that continues to be adjusted by addition and subtraction is 9-9.5, for example, it can be 9, 9.2 or 9.5, but it is not limited to the listed values, and other unlisted values in the numerical range are the same Be applicable.

Exemplarily, the copper-manganese liquid used to prepare high-priced manganese slag in the present invention is 5-10% of the copper-manganese liquid obtained by extraction, such as 5%, 6%, 8%, 9% or 10%, etc., and the remaining copper Manganese liquid can be used to prepare manganese sulfate.

Preferably, the amount of polyferric sulfate added during iron precipitation and silicon removal in step (4) is 2-3wt‰ of the volume of the oxidation solution, such as 2wt‰, 2.2wt‰, 2.5wt‰, 2.8wt‰ or 3wt‰ , but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the pH value of iron precipitation and silicon removal in step (4) is 4-4.5, such as 4, 4.2 or 4.5, but not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the end point of the pH adjustment in step (4) is 2-2.5, such as 2, 2.2, 2.4 or 2.5, but not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the extraction in step (4) includes extraction with extraction agent P204 and extraction with extraction agent P507 in sequence; the stripping solution obtained by extraction with extraction agent P204 is copper-manganese solution.

Preferably, the solid obtained from the second solid-liquid separation in step (4) is washed and filtered in sequence;

Preferably, the pH value of the washing liquid used for the water washing is 4.5-5, such as 4, 4.5, 4.6, 4.8 or 5.

Preferably, the oil and phosphorus removal described in the present invention is carried out using iron oxide yellow, and the addition amount of iron oxide yellow is 5-10g/L, such as 5g/L, 6g/L, 8g/L or 10g/L, but Not limited to the numerical values listed, other unlisted numerical values within the numerical range are also applicable.

The invention can absorb extractant and solvent oil by removing oil and phosphorus, and can reduce TOC by 50-80% and TP by 45-85%.

Preferably, the second-stage dissolving solution in step (3) and/or the filtrate obtained from the second solid-liquid separation in step (4) is used for slurrying in step (1).

When the second-stage dissolving solution in step (3) is used for slurrying in step (1), the oxidized first-stage dissolving solution in step (4) will be mixed with the previous batch of second-stage dissolving solution.

Compared with the prior art, the present invention has the following beneficial effects:

The method provided by the invention adopts the technical scheme of segmental leaching, which shortens the leaching time and improves the leaching efficiency; and the method provided by the invention uses ferrous sulfate as a reducing agent during the second-stage dissolution, avoiding the generation of sulfur dioxide from the source , reducing the safety risk and environmental protection pressure; in addition, the copper-manganese liquid produced in the extraction process is used as raw material to prepare high-priced manganese slag, which avoids the use of sodium chlorate, and also reduces the safety risk and environmental protection pressure; the method can eliminate the use of The addition of hazardous chemicals reduces safety risks and environmental pressures, improves the quality of the working environment for operators, and essentially realizes safe and environmentally friendly production.

Description of drawings

Fig. 1 is the process flow chart of utilizing nickel cobalt hydroxide to prepare battery-grade nickel sulfate provided by the present invention.

Detailed ways

The technical solutions of the present invention will be further described below through specific embodiments. It should be clear to those skilled in the art that the examples are only for helping to understand the present invention, and should not be regarded as specific limitations on the present invention.

The composition of the nickel-cobalt hydroxide treated in the specific embodiment of the present invention is shown in Table 1, wherein the unit of the element composition is wt%. Further definition of nickel cobalt hydroxide.

Table 1

co Cu Ni Fe Ca Mg Pb Zn mn Cd Cr Si 2.94 0.0007 22.39 1.58 0.036 3.76 0.00089 0.24 1.69 0.007 0.00017 2.32

Example 1

The present embodiment provides a method for preparing battery-grade nickel sulfate by using nickel cobalt hydroxide. The process flow diagram of the method is shown in Figure 1, including the following steps:

(1) Preleaching is performed after nickel cobalt hydroxide pulping to obtain a presoak solution; the preleaching is carried out using sulfuric acid with a concentration of 98wt%, the temperature of the preleaching is 75° C., and the pH value is 3.5; the solidification of the pulping The liquid ratio is 1:4, and the unit of solid-liquid ratio is g/L;

(2) The prepreg liquid obtained in step (1) is subjected to the first solid-liquid separation after one stage of dissolution to obtain insoluble slag and one stage of solution; the one stage of dissolution is carried out with sulfuric acid with a concentration of 98wt%, the temperature is 75°C, and the pH value is 1.2; the first solid-liquid separation is filtering;

(3) The insoluble slag obtained in step (2) is slurried and dissolved in two stages to obtain a two-stage solution; the reducing agent used in the two-stage dissolution is ferrous sulfate, and the quality of ferrous sulfate is 20% of the insoluble slag quality; Described slurrying adopts sulfuric acid to carry out, and solid-liquid ratio is 1.5:1, and the unit of solid-liquid ratio is g/L, and the sulfuric acid concentration during slurrying is 50g/L;

The temperature of the second-stage dissolution is 75° C., and the time is 30 minutes;

(4) Using high-priced manganese slag as an oxidizing agent to oxidize the solution obtained in step (2) to obtain an oxidizing solution; then carry out successively iron sinking and silicon removal, second solid-liquid separation, pH correction, extraction, oil and phosphorus removal and filtration, Obtain battery grade nickel sulfate;

The amount of polyferric sulfate added during the iron sinking and desiliconization is 2.5‰ of the volume of the oxidation solution, and the pH value is 4.2; the solid obtained from the second solid-liquid separation is washed and filtered in sequence, and the pH value of the washing liquid used for washing is 4.8 ; The callback pH value is adjusted to 2.2 using 98% sulfuric acid; the extraction includes the extraction of the extraction agent P204 and the extraction of the extraction agent P507; Phosphorus is carried out with iron oxide yellow, and the amount of iron oxide yellow added is 8g/L;

The high-priced manganese slag in step (4) is extracted by the extractant P204 to obtain the copper-manganese liquid after treatment: add sodium hydroxide to adjust the pH value of the copper-manganese liquid to 6.2; after filtering, continue to add Sodium hydroxide is used to adjust the pH value to 9.2, and high-valent manganese slag is obtained by solid-liquid separation.

The second-stage dissolving solution in step (3) and the filtrate obtained from the second solid-liquid separation in step (4) are reused for slurrying in step (1).

Example 2

The present embodiment provides a method for preparing battery-grade nickel sulfate by using nickel cobalt hydroxide. The process flow diagram of the method is shown in Figure 1, including the following steps:

(1) Preleaching is carried out after nickel cobalt hydroxide pulping, obtains presoaking solution; The sulfuric acid of described preleaching adopts 98wt% concentration to carry out, and the temperature of preleaching is 70 ℃, and pH value is 3; The solid of described pulping The liquid ratio is 1:3, and the unit of solid-liquid ratio is g/L;

(2) The presoak solution obtained in step (1) is subjected to the first solid-liquid separation after one stage of dissolution to obtain insoluble slag and one stage of dissolving solution; the one stage of dissolution is carried out with sulfuric acid with a concentration of 98wt%, and the temperature is 70° C., and the pH value is 1; the first solid-liquid separation is filtering;

(3) The insoluble slag obtained in step (2) is slurried and dissolved in two stages to obtain a two-stage solution; the reducing agent used in the two-stage dissolution is ferrous sulfate, and the quality of ferrous sulfate is 10% of the insoluble slag quality; Described slurrying adopts sulfuric acid to carry out, and solid-liquid ratio is 1.1:1, and the unit of solid-liquid ratio is g/L, and the sulfuric acid concentration during slurrying is 60g/L;

The temperature of the second-stage dissolution is 70°C, and the time is 30 minutes;

(4) Using high-priced manganese slag as an oxidizing agent to oxidize the solution obtained in step (2) to obtain an oxidizing solution; then carry out successively iron sinking and silicon removal, second solid-liquid separation, pH correction, extraction, oil and phosphorus removal and filtration, Obtain battery grade nickel sulfate;

The amount of polyferric sulfate added during the iron sinking and desiliconization is 2‰ of the volume of the oxidation solution, and the pH value is 4; the solid obtained from the second solid-liquid separation is washed and filtered in sequence, and the pH value of the washing liquid used for washing is 4.5 ; the callback pH value is adjusted to 2 using 98% sulfuric acid; the extraction includes the extraction of the extraction agent P204 and the extraction of the extraction agent P507; Phosphorus is carried out with iron oxide yellow, and the amount of iron oxide yellow added is 5g/L;

The high-priced manganese slag in step (4) is extracted by the extractant P204 to obtain the obtained copper-manganese liquid after treatment: add sodium hydroxide to adjust the pH value of the copper-manganese liquid to 6; after filtering, continue to add Sodium hydroxide is used to adjust the pH value to 9, and high-valent manganese slag is obtained by solid-liquid separation.

The second-stage dissolving solution in step (3) and the filtrate obtained from the second solid-liquid separation in step (4) are reused for slurrying in step (1).

Example 3

The present embodiment provides a method for preparing battery-grade nickel sulfate by using nickel cobalt hydroxide. The process flow diagram of the method is shown in Figure 1, including the following steps:

(1) Preleaching is performed after nickel cobalt hydroxide pulping to obtain a presoak; the preleaching is carried out using sulfuric acid with a concentration of 98wt%, the temperature of the preleaching is 80° C., and the pH value is 4; the solidification of the pulping The liquid ratio is 1:5, and the unit of solid-liquid ratio is g/L;

(2) The prepreg obtained in step (1) undergoes the first solid-liquid separation after one stage of dissolution to obtain insoluble slag and one stage of dissolving solution; the one stage of dissolution is carried out using sulfuric acid with a concentration of 98wt%, at a temperature of 80° C., and a pH of 1.5; the first solid-liquid separation is filtration;

(3) The insoluble slag obtained in step (2) is slurried and dissolved in two stages to obtain a two-stage solution; the reducing agent used in the two-stage dissolution is ferrous sulfate, and the quality of ferrous sulfate is 30% of the insoluble slag quality; Described slurrying adopts sulfuric acid to carry out, and solid-liquid ratio is 2:1, and the unit of solid-liquid ratio is g/L, and the sulfuric acid concentration during slurrying is 35g/L;

The temperature of the second-stage dissolution is 80°C, and the time is 30 minutes;

(4) Using high-priced manganese slag as an oxidizing agent to oxidize the solution obtained in step (2) to obtain an oxidizing solution; then carry out successively iron sinking and silicon removal, second solid-liquid separation, pH correction, extraction, oil and phosphorus removal and filtration, Obtain battery grade nickel sulfate;

The amount of polyferric sulfate added during the iron sinking and desiliconization is 3‰ of the volume of the oxidation solution, and the pH value is 4.5; the solid obtained from the second solid-liquid separation is washed and filtered in sequence, and the pH value of the washing liquid used for washing is 5 ; the callback pH value is adjusted to 2.5 using 98% sulfuric acid; the extraction includes the extraction of the extraction agent P204 and the extraction of the extraction agent P507; Phosphorus is carried out with iron oxide yellow, and the amount of iron oxide yellow added is 10g/L;

The high-priced manganese slag in step (4) is extracted by the extractant P204 to obtain the obtained copper-manganese liquid after treatment: add sodium hydroxide to adjust the pH value of the copper-manganese liquid to 6.5; after filtering, continue to add Sodium hydroxide is used to adjust the pH value to 9.5, and high-valent manganese slag is obtained by solid-liquid separation.

The second-stage dissolving solution in step (3) and the filtrate obtained from the second solid-liquid separation in step (4) are reused for slurrying in step (1).

The composition of the nickel sulfate solution after degreasing and phosphorus removal in the embodiment of the present invention is as shown in Table 2, and the unit that each element forms is g/L; The standard of battery grade nickel sulfate is that the concentration of each element satisfies: Ni≥125g/L L, Mg≤0.005g/L, Ca≤0.005g/L, Cu≤0.001g/L, Zn≤0.001g/L, Fe≤0.001g/L, Pb≤0.001g/L, Cd≤0.001g/L , Cr≤0.002g/L, Li≤0.002g/L, Si≤0.005g/L and total phosphorus (TP)≤0.01g/L.

Table 2

Wherein "N.D" in Table 2 means that it is below the detection limit and cannot be detected.

In summary, the method provided by the present invention adopts the technical scheme of segmental leaching, which shortens the leaching time and improves the leaching efficiency; The production of sulfur dioxide is avoided, which reduces the safety risk and environmental protection pressure; in addition, the high-priced manganese slag is prepared from the copper-manganese liquid produced in the extraction process, which avoids the use of sodium chlorate, and also reduces the safety risk and environmental protection pressure; The invention adopts a technical scheme of one-stage dissolution, first solid-liquid separation and two-stage dissolution, and reacts hydroxycobalt and nickel hydroxylation under medium-high acidity conditions, which saves the amount of reducing agent added, and greatly shortens the reaction time, which is conducive to promoting Continuous and stable production greatly saves time cost and medicament cost; the reducing agent used in the second-stage dissolution of the present invention is ferrous sulfate, and the use of ferrous sulfate avoids the generation of sulfur dioxide, and eliminates pollution sources and danger sources from the source; and, Using ferrous sulfate as a reducing agent in the second-stage dissolution is equivalent to supplementing iron at the front end of iron sinking and silicon removal, saving the amount of ferric iron to be added later.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any person skilled in the art is within the technical scope disclosed in the present invention. Easily conceivable changes or substitutions all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. a method utilizing nickel hydroxide cobalt to prepare battery-grade nickel sulfate, is characterized in that, described method comprises the steps: (1) carry out preleaching after nickel cobalt hydroxide pulping, obtain prepreg; (2) The prepreg obtained in step (1) is subjected to the first solid-liquid separation after one stage of dissolution to obtain insoluble slag and one stage of solution; (3) Step (2) gained insoluble slag is through pulping and two-stage dissolving, obtains two-stage dissolving liquid; The used reducing agent of described two-stage dissolving is ferrous sulfate; (4) Use high-priced manganese slag as an oxidizing agent to oxidize a solution obtained in step (2) to obtain an oxidizing solution; Three solid-liquid separations to obtain battery-grade nickel sulfate; The high-priced manganese slag described in step (4) is obtained after the copper-manganese liquid obtained by extraction is processed; Step (3) and step (4) are in no particular order. 2. The method according to claim 1, characterized in that the temperature of the pre-leaching described in step (1) is 70-80°C; Preferably, the pH value of the preleaching in step (1) is 3-4. 3. The method according to claim 1 or 2, characterized in that, the temperature of the first stage of dissolution in step (2) is 70-80°C; Preferably, the pH value of the stage of dissolution in step (2) is 1-1.5. 4. according to the method described in any one of claim 1-3, it is characterized in that, the slurrying described in step (3) is to use sulfuric acid to carry out slurrying, and the solid-liquid ratio of slurrying is (1-2): 1, The unit of the solid-to-liquid ratio is g/L; Preferably, during slurrying in step (3), the mass concentration of sulfuric acid is ≥35g/L. 5. The method according to any one of claims 1-4, characterized in that, the temperature of the second-stage dissolution in step (3) is 70-80°C; Preferably, the time for the second stage of dissolution in step (3) is ≤30 min. 6. according to the method described in any one of claim 1-5, it is characterized in that, the preparation method of high-priced manganese slag described in step (4) comprises the steps: The pH value of the copper-manganese solution is adjusted to 6-6.5; after filtration, the pH value is adjusted to 9-9.5 under the condition of feeding oxygen-containing gas, and high-priced manganese slag is obtained by solid-liquid separation. 7. according to the method described in any one of claim 1-6, it is characterized in that, the add-on of polymerized ferric sulfate is 2-3‰ of the volume of oxidation solution when the described step (4) sinks iron and desiliconizes; Preferably, the pH value of iron precipitation and silicon removal in step (4) is 4-4.5. 8. according to the method described in any one of claim 1-7, it is characterized in that, the end point value of callback pH value described in step (4) is 2-2.5; Preferably, the extraction in step (4) includes sequential extraction with extraction agent P204 and extraction with extraction agent P507; the stripping solution obtained by extraction with extraction agent P204 is copper-manganese solution. 9. The method according to any one of claims 1-8, characterized in that, the second solid-liquid separation of the step (4) obtained solids are washed and filtered successively; Preferably, the pH value of the water washing solution used for the water washing is 4.5-5. 10. The method according to claim 9, characterized in that the filtrate obtained from the second solid-liquid separation described in step (3) and/or step (4) is reused in step (1). pulping.

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