A method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue

Abstract

The present application belongs to the technical field of hydrometallurgy recovery, and particularly relates to a method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue. The method comprises the following steps: (1) one-stage high-temperature strong-acid reduction leaching and oxidation leaching; (2) two-stage high-temperature strong-acid reduction leaching and oxidation leaching; (3) purification and removal of iron and aluminum; (4) extraction and removal of impurities; (5) cobalt-nickel extraction separation; (6) resin oil removal; and (7) evaporation crystallization. The process flow of the present application is rationally designed and simple to operate. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue can make the cobalt leaching rate of cobalt sulfide roasting leaching residue reach more than 99%, and after the leaching solution is subjected to removal of iron and aluminum, extraction and removal of impurities, cobalt-nickel extraction separation and resin oil removal, pure cobalt sulfate or cobalt chloride solution can be obtained. The pure cobalt sulfate or cobalt chloride solution can be finally subjected to evaporation crystallization to produce qualified battery-grade cobalt sulfate crystals or cobalt chloride crystals.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical recovery technology, and in particular to a method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue. Background Technology

[0002] In the oxidative roasting process of cobalt sulfide, incomplete roasting and over-roasting can occur. The cobalt sulfide roasting leaching residue obtained by sulfuric acid leaching and reduction leaching mainly contains cobalt tetroxide, high-cobalt oxide, and cobalt sulfide. This residue is not only large in quantity but also contains over 40% cobalt. The cobalt in this residue has a very high recovery value, but currently, there is a lack of economically feasible and reasonable processing technology. Long-term stockpiling prevents the effective utilization of cobalt's extremely high economic value and hinders the recycling of cobalt resources. Furthermore, the large-scale stockpiling of cobalt sulfide leaching residue at production sites not only occupies production space but also poses a serious threat to the environment. Therefore, to recover the high-value cobalt from cobalt sulfide roasting leaching residue and turn waste into treasure, there is an urgent need to find an economical and efficient cobalt recovery technology.

[0003] Currently, the traditional leaching processes for cobalt sulfide roasting residue mainly employ sulfuric acid mixed low-temperature roasting and water leaching, and acid leaching and reduction leaching. The sulfuric acid mixed low-temperature roasting and water leaching process suffers from problems such as low cobalt leaching rate (60-70%), harsh roasting environment, and significant cobalt loss due to dust generation during the feeding process. The acid leaching and reduction leaching process also has problems such as low cobalt leaching rate (40-60%), large residue volume, generation of sulfur dioxide gas during the reaction, and high consumption of reducing agent.

[0004] For cobalt sulfide roasting leaching residue, an enhanced leaching process is proposed. This process involves accelerating the leaching reaction rate and speed under high temperature and strong acid conditions, while simultaneously increasing the leaching time of the strong reducing agent to fully reduce the high-valence oxides of cobalt. Then, a strong oxidizing agent is added to completely oxidize the cobalt sulfide in the cobalt sulfide roasting leaching residue. This allows the cobalt in the cobalt sulfide roasting leaching residue to be efficiently converted into a soluble cobalt solution, thus efficiently recovering the high-value cobalt from the cobalt sulfide roasting leaching residue.

[0005] Therefore, for cobalt sulfide roasting leaching residue with high recycling value but difficult processing, there is an urgent need for an enhanced leaching process for efficient cobalt recovery. This process involves leaching the high-value cobalt from the cobalt sulfide roasting leaching residue into a solution, while requiring a cobalt leaching rate of ≥99%. The cobalt-containing leaching solution is then purified to remove iron and aluminum, extracted to remove impurities, separated by cobalt and nickel extraction, and degreased with resin to obtain a pure cobalt solution. Finally, the solution is evaporated and crystallized to obtain battery-grade cobalt sulfate crystals and cobalt chloride crystals for sale.

[0006] This invention was proposed in response to the shortcomings of existing technologies. Summary of the Invention

[0007] The presence of both high-valence oxides and low-valence sulfides in cobalt sulfide roasting leaching residue presents challenges in treating it using sulfuric acid mixed roasting and water leaching processes and acid leaching-reduction leaching processes. These issues result in low leaching rates, large residue volumes, and harsh environmental conditions, hindering the efficient recovery of the high cobalt content in the residue. This invention provides a method for the efficient recovery of cobalt from cobalt sulfide roasting leaching residue. The method comprises the following steps: (1) a first-stage high-temperature strong acid reduction leaching and oxidative leaching; (2) a second-stage high-temperature strong acid reduction leaching and oxidative leaching; (3) purification to remove iron and aluminum; (4) extraction to remove impurities; (5) cobalt-nickel extraction and separation; (6) resin degreasing; and (7) evaporation and crystallization. The process flow design of this invention is reasonable and the operation is simple. The method for efficient cobalt recovery from cobalt sulfide roasting leaching residue disclosed in this invention employs a two-stage high-temperature strong acid reduction leaching and a two-stage oxidation leaching process to achieve a cobalt leaching rate of over 99% in the cobalt sulfide roasting leaching residue, yielding a high-cobalt leachate. After iron and aluminum removal, extraction and impurity removal, cobalt-nickel extraction and separation, and resin degreasing, the high-cobalt leachate yields a pure cobalt sulfate or cobalt chloride solution. This pure cobalt sulfate or cobalt chloride solution can then be evaporated and crystallized to produce qualified battery-grade cobalt sulfate or cobalt chloride crystals. This invention efficiently recovers cobalt from cobalt sulfide roasting leaching residue, and the high-cobalt leachate is further processed through a series of impurity removal processes to obtain battery-grade cobalt sulfate or cobalt chloride crystals. This method features a short processing flow, simple process, high cobalt leaching rate, and high product quality.

[0008] This invention can be achieved through the following technical solutions:

[0009] This invention provides a method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue, comprising the following steps:

[0010] (1). High-temperature strong acid reduction leaching and oxidation leaching: Weigh a certain amount of cobalt sulfide roasted leaching residue, add an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5), add a reducing agent for reduction leaching, the reaction time is 1-6 h, and the reaction temperature is controlled at 50-100℃. After the high-temperature strong acid reduction leaching is completed, add an oxidizing agent for oxidation leaching, the reaction time is 2-5 h, and the reaction temperature is controlled at 50-100℃ to obtain a high-temperature strong acid reduction oxidation leaching solution and a high-temperature strong acid reduction oxidation leaching residue.

[0011] (2). Two-stage high-temperature strong acid reduction leaching and oxidation leaching: Weigh the first-stage high-temperature strong acid reduction oxidation leaching residue obtained in step (1), add an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5), add a reducing agent for reduction leaching, the reaction time is 1-6 h, and the reaction temperature is controlled at 50-100℃. After the high-temperature strong acid reduction leaching is completed, add an oxidizing agent for oxidation leaching, the reaction time is 2-5 h, and the reaction temperature is controlled at 50-100℃ to obtain the two-stage high-temperature strong acid reduction oxidation leaching solution and the two-stage high-temperature strong acid reduction oxidation leaching residue.

[0012] (3). Purification and removal of iron and aluminum: The first-stage high-temperature strong acid reduction oxidation leaching solution and the second-stage high-temperature strong acid reduction oxidation leaching solution obtained in steps (1) and (2) are mixed. An alkaline neutralizing agent is added to the mixed leaching solution to remove iron and aluminum. The pH value is controlled at 3-5, the temperature at 30-60℃, and the reaction time at 1-3h to obtain a high cobalt purification solution and iron and aluminum purification residue.

[0013] (4). Extraction and impurity removal: The iron-aluminum-removed high cobalt purification solution obtained in step (3) contains small amounts of iron, aluminum, copper, manganese, calcium, zinc, chromium and other elements. It is then subjected to P204 organic extraction to remove impurities, resulting in a high cobalt P204 raffinate with further improved purity and a back-extraction solution containing iron, aluminum, copper, manganese, calcium, zinc and chromium.

[0014] (5). Cobalt-nickel extraction and separation: The high cobalt P204 raffinate obtained in step (4) contains a small amount of nickel, magnesium and other elements. Through P507 cobalt-nickel extraction and separation, a relatively pure high cobalt P507 back-extraction solution and a raffinate containing nickel and magnesium are obtained.

[0015] (6). Resin degreasing: The high cobalt P507 back-extraction solution obtained in step (5) is degreased by adsorption with degreasing resin to obtain a pure cobalt solution after degreasing;

[0016] (7). Evaporation and crystallization: The pure cobalt solution obtained in step (6) is subjected to MVR evaporation and crystallization to obtain battery-grade cobalt sulfate crystals or battery-grade cobalt chloride crystals, which can be sold as cobalt salt products.

[0017] Preferably, the cobalt sulfide roasting leaching residue in step (1) is the leaching residue obtained by traditional sulfuric acid leaching and reduction leaching processes from African cobalt sulfide copper ore after a series of processes such as sulfuric acid leaching, copper extraction, cobalt sulfide precipitation, and cobalt sulfide oxidation roasting. The cobalt sulfide oxidation roasting process has the problems of incomplete roasting and over-roasting. The cobalt sulfide roasting leaching residue mainly contains substances such as cobalt tetroxide, high cobalt oxide, and cobalt sulfide.

[0018] Preferably, the acidic solution in steps (1) and (2) is a sulfuric acid solution or a hydrochloric acid solution;

[0019] Preferably, the reducing agent in steps (1) and (2) is one or a mixture of sodium metabisulfite, sulfur dioxide, sodium sulfite, oxalic acid, and hydrogen peroxide;

[0020] Preferably, the oxidant in steps (1) and (2) is one or a mixture of sodium persulfate, ammonium persulfate, hydrogen peroxide, manganese dioxide, and sodium chlorate.

[0021] Preferably, the molar concentration of the reducing agent in steps (1) and (2) is 1:(1-3) of the molar concentration of cobalt in the cobalt sulfide roasting leaching residue.

[0022] Preferably, the amount of oxidant used in steps (1) and (2) is 30-50% of the mass of the cobalt sulfide roasting leaching residue.

[0023] Preferably, the cobalt sulfide roasting leaching residue in steps (1) and (2) adopts a two-stage high-temperature strong acid reduction leaching and a two-stage oxidation leaching, with a comprehensive cobalt leaching rate ≥99%. The content of each valuable metal in the two-stage high-temperature strong acid reduction oxidation leaching residue is as follows: cobalt <1%, nickel <0.1%, copper <0.1%, manganese <0.1%.

[0024] Preferably, the alkaline neutralizing agent in step (3) is one of sodium hydroxide solution, calcium hydroxide emulsion, ammonia solution, or heavy calcium carbonate powder.

[0025] Preferably, the P204 extraction organic phase in step (4) consists of 10-20% P204 and 80-90% 260# solvent oil; the organic phase is first saponified with 20-30% liquid alkali solution, and after saponification, the organic phase is subjected to multi-stage countercurrent extraction of the iron, aluminum and cobalt purified liquid obtained in step (3), and the loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution.

[0026] Preferably, the P507 extraction organic phase in step (5) consists of 20-40% P507 and 60-80% 260# solvent oil; the organic phase is first saponified with 20-30% liquid alkali solution, and after saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high cobalt P204 raffinate obtained in step (4), and the loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution or 2-4 mol / L sulfuric acid solution.

[0027] Preferably, the oil content of the pure cobalt solution in step (6) is less than 1 mg / L.

[0028] Compared with existing technologies, the present invention has the following advantages:

[0029] (1) Cobalt sulfide roasting leaching residue is a high-value cobalt slag. Using existing technologies, the high cobalt content in the residue is difficult to recover efficiently, leading to long-term stockpiling and difficult treatment. The present invention addresses this issue by achieving a cobalt leaching rate of over 99% in the cobalt sulfide roasting leaching residue. Furthermore, the high-cobalt leachate, after iron and aluminum removal, extraction and impurity removal, cobalt-nickel extraction and separation, resin degreasing, and evaporation crystallization, can produce battery-grade cobalt sulfate crystals or cobalt chloride crystals. This invention efficiently recovers cobalt from the cobalt sulfide roasting leaching residue, and the high-cobalt leachate, through a series of impurity removal processes, yields battery-grade cobalt sulfate crystals or cobalt chloride crystals. The process is short, simple, has a high cobalt leaching rate, and produces high-quality products.

[0030] (2) Combining enterprise development and market demand, high-value sulfurized roasting leaching residue is used to produce pure battery-grade cobalt sulfate crystals or cobalt chloride crystals. The products can be sold directly or applied to the field of ternary cathode precursors or 3C batteries. Attached Figure Description

[0031] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 This is a process flow diagram of the present invention; Detailed Implementation

[0033] The present invention will now be described in detail with reference to specific embodiments. The embodiments shown below do not limit the scope of the invention as described in the claims. Furthermore, the complete contents of the configurations shown in the embodiments below are not limited to those necessary for the solution of the invention described in the claims.

[0034] A method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue includes the following steps:

[0035] (1) High-temperature strong acid reduction leaching and oxidative leaching: A certain amount of cobalt sulfide roasting leaching residue was weighed and mixed with an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5). A reducing agent was added for reduction leaching, and the reaction time was 1-6 h, with the reaction temperature controlled at 50-100℃. After the high-temperature strong acid reduction leaching was completed, an oxidizing agent was added for oxidative leaching, and the reaction time was 2-5 h, with the reaction temperature controlled at 50-100℃. A first-stage high-temperature strong acid reduction oxidative leaching solution and a first-stage high-temperature strong acid reduction oxidative leaching residue were obtained. The cobalt sulfide roasting leaching residue is the leaching residue obtained by traditional sulfuric acid leaching and reduction leaching processes from African cobalt sulfide copper ore after sulfuric acid leaching, copper extraction, cobalt sulfide precipitation, and cobalt sulfide oxidative roasting. The cobalt sulfide oxidative roasting process has incomplete roasting and over-roasting issues. The cobalt sulfide roasting leaching residue mainly contains cobalt tetroxide, high cobalt oxide, cobalt sulfide, and other substances. The acidic solution is a sulfuric acid solution or a hydrochloric acid solution. The reducing agent is one or a mixture of sodium metabisulfite, sulfur dioxide, sodium sulfite, oxalic acid, and hydrogen peroxide, and the molar concentration of the reducing agent is 1:(1-3) of the molar concentration of cobalt in the cobalt sulfide roasting leaching residue. The oxidizing agent is one or a mixture of sodium persulfate, ammonium persulfate, hydrogen peroxide, manganese dioxide, and sodium chlorate, and the amount of oxidizing agent used is 30-50% of the mass of the cobalt sulfide roasting leaching residue.

[0036] (2) Two-stage high-temperature strong acid reduction leaching and oxidative leaching: Weigh the first-stage high-temperature strong acid reduction oxidative leaching residue obtained in step (1), add an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5), mix, add a reducing agent for reduction leaching, the reaction time is 1-6 h, and the reaction temperature is controlled at 50-100℃. After the high-temperature strong acid reduction leaching is completed, add an oxidizing agent for oxidative leaching, the reaction time is 2-5 h, and the reaction temperature is controlled at 50-100℃. Two-stage high-temperature strong acid reduction oxidative leaching solution and two-stage high-temperature strong acid reduction oxidative leaching residue are obtained. The acidic solution is a sulfuric acid solution or a hydrochloric acid solution. The reducing agent is one or more of sodium metabisulfite, sulfur dioxide, sodium sulfite, oxalic acid, and hydrogen peroxide, and the molar concentration of the reducing agent is 1:(1-3) of the molar concentration of cobalt in the cobalt sulfide roasting leaching residue. The oxidant is one or a mixture of sodium persulfate, ammonium persulfate, hydrogen peroxide, manganese dioxide, and sodium chlorate, and the amount of oxidant used is 30-50% of the mass of the cobalt sulfide roasting leaching residue. The cobalt sulfide roasting leaching residue undergoes two-stage high-temperature strong acid leaching, two-stage reduction leaching, and two-stage oxidation leaching, with a comprehensive cobalt leaching rate ≥99%. The content of each valuable metal in the two-stage high-temperature strong acid reduction oxidation leaching residue is as follows: cobalt <1%, nickel <0.1%, copper <0.1%, manganese <0.1%.

[0037] (3) Purification and removal of iron and aluminum: The first-stage high-temperature strong acid reduction oxidation leaching solution and the second-stage high-temperature strong acid reduction leaching solution obtained in steps (1) and (2) are mixed. An alkaline neutralizing agent is added to the mixed cobalt leaching solution to remove iron and aluminum. The pH value is controlled at 3-5, the temperature at 30-60℃, and the reaction time is 1-3 hours to obtain a high-cobalt purified solution and iron-aluminum purified slag. The alkaline neutralizing agent is a mixture of sodium hydroxide solution, calcium hydroxide emulsion, ammonia solution, and heavy calcium carbonate powder.

[0038] (4) Extraction and impurity removal: The high-cobalt purified solution obtained in step (3) contains small amounts of iron, aluminum, copper, manganese, calcium, zinc, chromium and other elements. Impurities are removed by P204 organic extraction to obtain a high-cobalt P204 raffinate with further improved purity and a back-extraction solution containing iron, aluminum, copper, manganese, calcium, zinc and chromium. The organic phase of P204 extraction consists of 10-20% P204 and 80-90% 260# solvent oil. The organic phase is first saponified with 20-30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt purified solution obtained in step (3). The loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution.

[0039] (5) Cobalt-nickel extraction and separation: The high-cobalt P204 raffinate obtained in step (4) contains a small amount of nickel, magnesium and other elements. It is separated by P507 cobalt-nickel extraction to obtain a relatively pure high-cobalt P507 back-extraction solution and a raffinate containing nickel and magnesium. The organic phase of P507 extraction consists of 20-40% P507 and 60-80% 260# solvent oil. The organic phase is first saponified with 20-30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt P204 raffinate obtained in step (4). The loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution or 2-4 mol / L sulfuric acid solution.

[0040] (6) Resin degreasing: The high-cobalt P507 back-extraction solution obtained in step (5) is degreased by adsorption with degreasing resin to obtain a pure cobalt solution after degreasing. The oil content of the pure cobalt solution is less than 1 mg / L.

[0041] (7) Evaporation and crystallization: The pure cobalt solution obtained in step (6) is subjected to MVR evaporation and crystallization to obtain battery-grade cobalt sulfate or cobalt chloride crystals, which can be sold as cobalt salt products.

[0042] The embodiments of the present invention will be described in detail below:

[0043] Example 1:

[0044] This invention discloses a method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue. The detailed steps of this method are as follows:

[0045] (1) High-temperature strong acid reduction leaching and oxidative leaching: Weigh 500g of cobalt sulfide roasted leaching residue and mix it with sulfuric acid solution with a hydrogen ion concentration of 6mol / L at a solid-liquid ratio of 1:5. After mixing, add oxalic acid at a molar concentration of 1:2.5 to cobalt molar concentration in the cobalt sulfide roasted leaching residue for reduction leaching. The reaction time is 4h, and the reaction temperature is controlled at 80℃. After the high-temperature strong acid reduction leaching is completed, add sodium chlorate at 35% of the mass of the cobalt sulfide roasted leaching residue for oxidative leaching. The reaction time is 4h, and the reaction temperature is controlled at 80℃. A first-stage high-temperature strong acid reduction oxidative leaching solution and a first-stage high-temperature strong acid reduction oxidative leaching residue are obtained.

[0046] The main chemical reactions that occur in the sulfurized roasted leaching residue during the high-temperature strong acid reduction leaching and oxidative leaching process are as follows:

[0047] Co3O4+3H2SO4+H2C2O4·2H2O=3CoSO4+2CO2↑+6H2O

[0048] Co2O3+2H2SO4+H2C2O4·2H2O=2CoSO4+2CO2↑+5H2O

[0049] CoS+H2SO4+2NaClO3=CoSO4+Na2SO4+2ClO2↑+H2O

[0050] Results of a high-temperature strong acid reduction leaching and oxidation leaching process:

[0051]

[0052] (2) Two-stage high-temperature strong acid reduction leaching and oxidative leaching: Take 120g of the above-mentioned first-stage high-temperature strong acid reduction oxidative leaching residue, add sulfuric acid solution with a hydrogen ion concentration of 6mol / L at a solid-liquid ratio of 1:5, mix, and add oxalic acid at a molar concentration of 1:2.5 to the molar concentration of cobalt in the cobalt sulfide roasted leaching residue for reduction leaching. The reaction time is 5h, and the reaction temperature is controlled at 80℃. After the high-temperature strong acid reduction leaching is completed, add sodium chlorate at 35% of the mass of the cobalt sulfide roasted leaching residue for oxidative leaching. The reaction time is 3h, and the reaction temperature is controlled at 80℃. Two-stage high-temperature strong acid reduction oxidative leaching solution and two-stage high-temperature strong acid reduction oxidative leaching residue are obtained.

[0053] The main chemical reactions that occur in the first-stage high-temperature strong acid reduction oxidative leaching residue during the second-stage high-temperature strong acid reduction leaching and oxidative leaching are as follows:

[0054] Co3O4+3H2SO4+H2C2O4·2H2O=3CoSO4+2CO2↑+6H2O

[0055] Co2O3+2H2SO4+H2C2O4·2H2O=2CoSO4+2CO2↑+5H2O

[0056] CoS+H2SO4+2NaClO3=CoSO4+Na2SO4+2ClO2↑+H2O

[0057] Results of two-stage high-temperature strong acid reduction leaching and oxidation leaching:

[0058]

[0059] (3) Purification to remove iron and aluminum: The first stage of high-temperature strong acid reduction oxidation leaching solution and the second stage of high-temperature strong acid reduction oxidation leaching solution are mixed. Heavy calcium carbonate powder is added to the mixed cobalt leaching solution to remove iron and aluminum. The pH value is controlled at 4.0, the temperature is 60℃, and the reaction is carried out for 2 hours to obtain a high cobalt purified solution with iron and aluminum removal and iron and aluminum purified residue.

[0060] The main chemical reactions that occur in the mixed cobalt leaching solution during the purification and removal of iron and aluminum are:

[0061] Fe2(SO4)3+5H2SO4+8CaCO3=2Fe(OH)3↓+8CaSO4↓+8CO2↑

[0062] +2H2O

[0063] Al2(SO4)3+5H2SO4+8CaCO3=2Al(OH)3↓+8CaSO4↓+8CO2↑

[0064] +2H2O

[0065] Results of purification and removal of iron and aluminum:

[0066]

[0067] (4) Extraction and impurity removal: The high-cobalt purification solution containing iron, aluminum, and manganese contains small amounts of elements such as aluminum, copper, manganese, calcium, zinc, and chromium. Impurities are removed by P204 organic extraction to obtain a high-cobalt P204 raffinate with further improved purity and a back-extraction solution containing iron, aluminum, copper, manganese, calcium, zinc, and chromium. The organic phase of the P204 extraction consists of 15% P204 and 85% 260# solvent oil. The organic phase is first saponified with a 30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt purification solution containing iron, aluminum, and manganese. The loaded organic phase is back-extracted with a 2.5 mol / L hydrochloric acid solution.

[0068] The main chemical reactions involved in P204 extraction and impurity removal are:

[0069] Saponification reaction formula: HR + NaOH = NaR + H2O

[0070] Extraction reaction formula for high-cobalt and iron-aluminum purification solution: CoSO4 + 2NaR = CoR2 + Na2SO4

[0071] Hydrochloric acid back-extraction reaction formula: CoR2 + 2HCl = CoCl2 + 2HR

[0072] Extraction and impurity removal results:

[0073]

[0074] (5) Cobalt-nickel extraction and separation: The high-cobalt P204 raffinate contains a small amount of nickel, magnesium and other elements. It is separated by P507 cobalt-nickel extraction to obtain a relatively pure high-cobalt P507 back-extraction solution and a raffinate containing nickel and magnesium. The organic phase of the P507 extraction consists of 30% P507 and 70% 260# solvent oil. The organic phase is first saponified with 30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt P204 raffinate. The loaded organic phase is back-extracted with 2.5 mol / L sulfuric acid solution.

[0075] The main chemical reactions involved in the separation of cobalt and nickel in P507:

[0076] Saponification reaction formula: HR + NaOH = NaR + H2O

[0077] Extraction reaction formula for high cobalt P204 raffinate: CoSO4 + 2NaR = CoR2 + Na2SO4

[0078] Sulfuric acid back-extraction reaction formula: CoR2 + H2SO4 = CoSO4 + 2HR

[0079] Results of cobalt-nickel extraction and separation:

[0080]

[0081]

[0082] (6) Resin degreasing: The high-cobalt P507 back-extraction solution obtained in step (5) is degreased by adsorption with degreasing resin to obtain a pure cobalt solution after degreasing. The oil content of the pure cobalt solution is less than 1 mg / L.

[0083] (7) Evaporation and crystallization: The pure cobalt solution obtained in step (6) is subjected to MVR evaporation and crystallization to obtain battery-grade cobalt sulfate crystals, which can be sold as cobalt salt products.

[0084] Analysis results of battery-grade cobalt sulfate crystal products;

[0085]

[0086] Example 2:

[0087] This invention discloses a method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue. The detailed steps of this method are as follows:

[0088] (1) High-temperature strong acid reduction leaching and oxidative leaching: Weigh 500g of cobalt sulfide roasted leaching residue and mix it with hydrochloric acid solution with a hydrogen ion concentration of 3mol / L at a solid-liquid ratio of 1:5. Add oxalic acid at a molar concentration of 1:2 to cobalt molar concentration in the cobalt sulfide roasted leaching residue for reduction leaching. The reaction time is 4h, and the reaction temperature is controlled at 80℃. After the high-temperature strong acid reduction leaching is completed, add sodium persulfate at 30% of the mass of the cobalt sulfide roasted leaching residue for oxidative leaching. The reaction time is 4h, and the reaction temperature is controlled at 80℃. A first-stage high-temperature strong acid reduction oxidative leaching solution and a first-stage high-temperature strong acid reduction oxidative leaching residue are obtained.

[0089] The main chemical reactions that occur in the sulfurized roasted leaching residue during the high-temperature strong acid reduction leaching and oxidative leaching process are as follows:

[0090] Co3O4+6HCl+H2C2O4·2H2O=3CoCl2+2CO2↑+6H2O

[0091] Co2O3+4HCl+H2C2O4·2H2O=2CoCl2+2CO2↑+5H2O

[0092] CoS+4HCl+Na2S2O8=CoCl2+2NaCl+3SO2↑+2H2O

[0093] Results of a high-temperature strong acid reduction leaching and oxidation leaching process:

[0094]

[0095] (2) Two-stage high-temperature strong acid reduction leaching and oxidative leaching: Take 100g of the above-mentioned first-stage high-temperature strong acid reduction oxidative leaching residue, add hydrochloric acid solution with a hydrogen ion concentration of 3mol / L at a solid-liquid ratio of 1:5, mix, and add oxalic acid at a molar concentration of 1:2 to the molar concentration of cobalt in the cobalt sulfide roasted leaching residue for reduction leaching. The reaction time is 5h, and the reaction temperature is controlled at 80℃. After the high-temperature strong acid reduction leaching is completed, add sodium persulfate at 30% of the mass of the cobalt sulfide roasted leaching residue for oxidative leaching. The reaction time is 3h, and the reaction temperature is controlled at 80℃. Two-stage high-temperature strong acid reduction oxidative leaching solution and two-stage high-temperature strong acid reduction oxidative leaching residue are obtained.

[0096] The main chemical reactions that occur in the sulfurized roasted leaching residue during the two-stage high-temperature strong acid reduction leaching and oxidative leaching are as follows:

[0097] Co3O4+6HCl+H2C2O4·2H2O=3CoCl2+2CO2↑+6H2O

[0098] Co2O3+4HCl+H2C2O4·2H2O=2CoCl2+2CO2↑+5H2O

[0099] CoS+4HCl+Na2S2O8=CoCl2+2NaCl+3SO2↑+2H2O

[0100] Results of two-stage high-temperature strong acid reduction leaching and oxidation leaching:

[0101]

[0102]

[0103] (3) Purification to remove iron and aluminum: The first stage of high-temperature strong acid reduction oxidation leaching solution and the second stage of high-temperature strong acid reduction oxidation leaching solution are mixed. Heavy calcium carbonate powder is added to the mixed cobalt leaching solution to remove iron and aluminum. The pH value is controlled at 4.0, the temperature is 60℃, and the reaction is carried out for 2 hours to obtain a high cobalt purified solution with iron and aluminum removal and iron and aluminum purified residue.

[0104] The main chemical reactions that occur in the mixed leaching solution during the purification and removal of iron and aluminum are:

[0105] FeCl3+5HCl+4CaCO3=Fe(OH)3↓+4CaCl2+4CO2↑+H2O

[0106] AlCl3+5HCl+4CaCO3=Al(OH)3↓+4CaCl2+4CO2↑+H2O

[0107] Results of purification and removal of iron and aluminum:

[0108]

[0109] (4) Extraction and impurity removal: The high-cobalt purification solution containing iron, aluminum, and manganese contains small amounts of elements such as aluminum, copper, manganese, calcium, zinc, and chromium. Impurities are removed by P204 organic extraction to obtain a high-cobalt P204 raffinate with further improved purity and a back-extraction solution containing iron, aluminum, copper, manganese, calcium, zinc, and chromium. The organic phase of the P204 extraction consists of 15% P204 and 85% 260# solvent oil. The organic phase is first saponified with a 30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt purification solution containing iron, aluminum, and manganese. The loaded organic phase is back-extracted with a 2.5 mol / L hydrochloric acid solution.

[0110] The main chemical reactions involved in P204 extraction and impurity removal are:

[0111] Saponification reaction formula: HR + NaOH = NaR + H2O

[0112] Extraction reaction formula for high-cobalt and iron-aluminum purification solution: CoCl2 + 2NaR = CoR2 + 2NaCl

[0113] Hydrochloric acid back-extraction reaction formula: CoR2 + 2HCl = CoCl2 + 2HR

[0114] Results of P204 extraction for impurity removal:

[0115]

[0116] (5) Cobalt-nickel extraction and separation: The high-cobalt P204 raffinate contains a small amount of nickel, magnesium and other elements. It is separated by P507 cobalt-nickel extraction to obtain a relatively pure high-cobalt P507 back-extraction solution and a raffinate containing nickel and magnesium. The organic phase of the P507 extraction consists of 30% P507 and 70% 260# solvent oil. The organic phase is first saponified with 30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high-cobalt P204 raffinate. The loaded organic phase is back-extracted with 2.5 mol / L hydrochloric acid solution.

[0117] The main chemical reactions involved in cobalt-nickel extraction and separation are:

[0118] Saponification reaction formula: HR + NaOH = NaR + H2O

[0119] Extraction reaction formula for high-cobalt P204 raffinate: CoCl2 + 2NaR = CoR2 + 2NaCl

[0120] Hydrochloric acid back-extraction reaction formula: CoR2 + 2HCl = CoCl2 + 2HR

[0121] P507 Cobalt-Nickel Separation Results:

[0122]

[0123]

[0124] (6) Resin degreasing: The high-cobalt P507 back-extraction solution is degreased by adsorption with degreasing resin to obtain a pure cobalt solution after degreasing. The oil content of the pure cobalt solution is less than 1 mg / L.

[0125] (7) Evaporation and crystallization: The pure cobalt solution obtained in step (6) is subjected to MVR evaporation and crystallization to obtain battery-grade cobalt chloride crystals, which can be sold as cobalt salt products.

[0126] Analysis results of battery-grade cobalt chloride crystal products;

[0127]

[0128] The above are merely preferred embodiments of the present invention. It should be noted that, for those skilled in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the technical principles of the present invention. These changes, modifications, substitutions and variations should also be considered within the scope of protection of the present invention.

Claims

1. A method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue, characterized in that, Includes the following steps: (1). High-temperature strong acid reduction leaching and oxidation leaching: Weigh a certain amount of cobalt sulfide roasted leaching residue, add an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5), add a reducing agent for reduction leaching, the reaction time is 1-6 h, and the reaction temperature is controlled at 50-100℃. After the high-temperature strong acid reduction leaching is completed, add an oxidizing agent for oxidation leaching, the reaction time is 2-5 h, and the reaction temperature is controlled at 50-100℃ to obtain a high-temperature strong acid reduction oxidation leaching solution and a high-temperature strong acid reduction oxidation leaching residue. (2). Two-stage high-temperature strong acid reduction leaching and oxidation leaching: Weigh the first-stage high-temperature strong acid reduction oxidation leaching residue obtained in step (1), add an acidic solution with a hydrogen ion concentration of 2-6 mol / L at a solid-liquid ratio of 1:(3-5), add a reducing agent for reduction leaching, the reaction time is 1-6 h, and the reaction temperature is controlled at 50-100℃. After the high-temperature strong acid reduction leaching is completed, add an oxidizing agent for oxidation leaching, the reaction time is 2-5 h, and the reaction temperature is controlled at 50-100℃ to obtain the two-stage high-temperature strong acid reduction oxidation leaching solution and the two-stage high-temperature strong acid reduction oxidation leaching residue. (3). Purification and removal of iron and aluminum: The first-stage high-temperature strong acid reduction oxidation leaching solution and the second-stage high-temperature strong acid reduction oxidation leaching solution obtained in steps (1) and (2) are mixed. An alkaline neutralizing agent is added to the mixed leaching solution to remove iron and aluminum. The pH value is controlled at 3-5, the temperature at 30-60℃, and the reaction time at 1-3h to obtain a high cobalt purification solution and iron and aluminum purification residue. (4). Extraction and impurity removal: The iron-aluminum-cobalt-free purified liquid obtained in step (3) is subjected to P204 organic extraction to remove impurities, resulting in a high-cobalt P204 raffinate with further improved purity and a back-extraction liquid containing iron, aluminum, copper, manganese, calcium, zinc, and chromium. (5). Cobalt-nickel extraction and separation: The high cobalt P204 raffinate obtained in step (4) is separated by P507 cobalt-nickel extraction to obtain a relatively pure high cobalt P507 back-extraction solution and a raffinate containing nickel and magnesium. (6). Resin degreasing: The high cobalt P507 back-extraction solution obtained in step (5) is degreased by adsorption with degreasing resin to obtain a pure cobalt solution after degreasing; (7). Evaporation and crystallization: The pure cobalt solution obtained in step (6) is subjected to MVR evaporation and crystallization to obtain battery-grade cobalt sulfate crystals or battery-grade cobalt chloride crystals, which can be sold as cobalt salt products.

2. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The cobalt sulfide roasting leaching residue mentioned in step (1) is the leaching residue obtained by traditional sulfuric acid leaching and reduction leaching processes from African cobalt sulfide copper ore after a series of processes including sulfuric acid leaching, copper extraction, cobalt sulfide precipitation, and cobalt sulfide oxidation roasting. The cobalt sulfide roasting leaching residue mainly contains cobalt tetroxide, high cobalt oxide, and cobalt sulfide.

3. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The acidic solution mentioned in steps (1) and (2) is a sulfuric acid solution or a hydrochloric acid solution; the reducing agent mentioned in steps (1) and (2) is one or more of sodium metabisulfite, sulfur dioxide, sodium sulfite, oxalic acid, and hydrogen peroxide; the oxidizing agent mentioned in steps (1) and (2) is one or more of sodium persulfate, ammonium persulfate, hydrogen peroxide, manganese dioxide, and sodium chlorate.

4. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The molar concentration of the reducing agent mentioned in steps (1) and (2) is 1:(1-3) with the molar concentration of cobalt in the cobalt sulfide roasting leaching residue.

5. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The amount of oxidant used in steps (1) and (2) is 30-50% of the mass of the cobalt sulfide roasting leaching residue.

6. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The alkaline neutralizing agent mentioned in step (3) is one of sodium hydroxide solution, calcium hydroxide emulsion, ammonia solution or heavy calcium carbonate powder.

7. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The organic phase of the P204 extraction in step (4) consists of 10-20% P204 and 80-90% 260# solvent oil. The organic phase is first saponified with 20-30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the iron, aluminum and cobalt purified liquid obtained in step (3). The loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution.

8. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The organic phase of the P507 extraction in step (5) consists of 20-40% P507 and 60-80% 260# solvent oil. The organic phase is first saponified with 20-30% liquid alkali solution. After saponification, the organic phase is subjected to multi-stage countercurrent extraction of the high cobalt P204 raffinate obtained in step (4). The loaded organic phase is back-extracted with 2-4 mol / L hydrochloric acid solution or 2-4 mol / L sulfuric acid solution.

9. The method for efficiently recovering cobalt from cobalt sulfide roasting leaching residue according to claim 1, characterized in that: The oil content of the pure cobalt solution in step (6) is less than 1 mg / L.

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