Method for comprehensively recovering metal from nickel-cobalt hydroxide containing scandium, copper and manganese

Abstract

The invention discloses a method for comprehensively recovering metal from nickel-cobalt hydroxide containing scandium, copper and manganese. The method comprises the following steps: carrying out acid leaching on nickel-cobalt hydroxide containing scandium, copper and manganese to obtain nickel-cobalt leachate containing scandium and copper and manganese-containing leaching residues, and precipitating scandium and copper in the nickel-cobalt leachate containing scandium and copper by adjusting the pH value to obtain precipitation residues I containing scandium and copper and nickel-cobalt purified liquid; and returning the precipitation slag I containing scandium and copper to the acid leaching process until the concentration of scandium in the nickel-cobalt leaching solution containing scandium and copper is not lower than 1.5 g / L and / or the concentration of copper is not lower than 7.5 g / L, and respectively recovering scandium and copper in the nickel-cobalt leaching solution containing scandium and copper through extraction separation, the raffinate I obtained in the scandium extraction and separation process is directly returned to the acid leaching process or is continuously subjected to copper extraction and separation; and adjusting the pH value of raffinate II obtained in the copper extraction separation process to precipitate residual scandium and copper, and returning obtained precipitation slag II containing scandium and copper to the acid leaching process. According to the method, the recovery rate of scandium, copper, manganese, nickel and cobalt can be remarkably increased, and the comprehensive utilization rate of the laterite-nickel ore is increased.

Description

Technical Field

[0001] The invention relates to a metal recovery method, in particular to a method for comprehensively recovering metals from nickel-cobalt hydroxide containing scandium, copper and manganese, and belongs to the technical field of hydrometallurgy. Background Art

[0002] With the surge in global demand for nickel resources and the depletion of sulfide nickel ore resources, the development and utilization of laterite nickel ore resources has gradually become the mainstream trend of the nickel industry. In this context, the high-pressure acid leaching process has been widely used and promoted in the field of laterite nickel ore hydrometallurgy due to its excellent adaptability, high leaching efficiency, high nickel and cobalt recovery rate and low production cost.

[0003] Laterite nickel ore not only contains rich nickel and cobalt resources, but also contains trace amounts of metal elements such as scandium, copper, and manganese, which are mainly found in the goethite and bauxite phases in the ore. In the process of smelting laterite nickel ore by high-pressure acid leaching, not only nickel and cobalt are effectively extracted, but also metal elements such as scandium, copper, and manganese are enriched to a certain extent. Specifically, laterite nickel ore is first pretreated into a nickel-cobalt hydroxide intermediate product, and then a nickel-cobalt leaching solution is generated through an acid leaching process, while scandium, copper, and manganese enter the leaching residue in the pre-neutralization stage. However, the current domestic treatment of laterite nickel ore mainly focuses on the extraction of nickel and cobalt, and relatively ignores the recovery of other metal elements with economic value in the ore, such as scandium, copper, and manganese. The existing extraction technologies for these elements generally have problems such as lengthy processes, complex operations, large consumption of raw and auxiliary materials, and high costs.

[0004] Therefore, developing a new method to efficiently and comprehensively recover valuable metals such as scandium, copper, and manganese from nickel-cobalt hydroxide during the hydrometallurgical smelting of laterite nickel ore is of great significance for optimizing resource utilization and improving economic benefits. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese. The method can greatly improve the recovery rate of scandium, copper, manganese and nickel-cobalt elements, and obtain high-purity nickel-cobalt products.

[0006] In order to achieve the above technical purpose, the present invention provides a method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese. The method comprises the following steps: subjecting the nickel-cobalt hydroxide containing scandium, copper and manganese to acid leaching to obtain a nickel-cobalt leaching solution containing scandium and copper and a leaching residue containing manganese; the nickel-cobalt leaching solution containing scandium and copper is precipitated with scandium-copper by adjusting the pH value to obtain a precipitated residue I containing scandium-copper and a nickel-cobalt purified solution; the precipitated residue I containing scandium-copper is returned to the acid leaching process until the concentration of scandium in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and / or the concentration of copper is not less than 7.5 g / L, and then the scandium and copper are respectively recovered by extraction and separation, wherein the raffinate I obtained in the scandium extraction and separation process is directly returned to the acid leaching process or copper extraction and separation is continued; the raffinate II obtained in the copper extraction and separation process is precipitated with the remaining scandium-copper by adjusting the pH value to obtain a precipitated residue II containing scandium-copper and returned to the acid leaching process.

[0007] The present invention first separates manganese through an acid leaching process, and then controls the precipitation and separation of scandium and copper from the leaching solution by adjusting the pH value of the leaching solution, and simultaneously obtains a purified nickel-cobalt solution, and the precipitated residue containing scandium and copper is continuously returned to the acid leaching process to enrich the scandium and copper elements, until the scandium and copper enrichment concentrations in the nickel-cobalt leaching solution containing scandium and copper reach a certain concentration, and then extracts and separates scandium and copper respectively, wherein the scandium enrichment concentration in the leaching solution reaches 1.5 g / L or more, and then the leaching solution can be further purified. Scandium extraction and separation is performed, and copper extraction and separation can be performed when the copper enrichment concentration in the leachate reaches 7.5g / L or above. If the scandium raffinate obtained in the process of scandium extraction and separation contains a copper element concentration of 7.5g / L or above, copper extraction and separation is performed, otherwise it is directly returned to the acid leaching process to continue to enrich scandium copper; the copper raffinate obtained in the copper extraction and separation process can be precipitated with the remaining scandium copper by adjusting the pH, and then the precipitated residue is recycled to the acid leaching process for enriching scandium copper. The present invention greatly improves the recovery rate of scandium and copper by continuously circulating and enriching scandium copper in the system and then separating it.

[0008] As a preferred solution, the mass content of scandium in the nickel-cobalt hydroxide containing scandium, copper and manganese is not higher than 0.1%, and the mass content of copper is not higher than 0.5%. The present invention can effectively extract and separate the metal elements from the nickel-cobalt hydroxide with lower scandium, copper and manganese contents.

[0009] As a preferred solution, the acid leaching conditions are as follows: using concentrated sulfuric acid as a leaching agent, the amount of the leaching agent relative to the nickel element in the nickel-cobalt hydroxide containing scandium, copper and manganese is 1.5-3t / tNi, more preferably 1.8-2.3t / tNi; while controlling the concentration of H2SO4 in the nickel-cobalt leaching solution containing scandium and copper to be 20-80g / L, more preferably 30-50g / L. The leaching temperature is 60-110°C, more preferably 85-100°C, and the leaching time is 0.5-4.5h, more preferably 1-3h.

[0010] The acid leaching process uses concentrated sulfuric acid as a leaching agent, which is cheap and significantly reduces production costs compared to other acids. In addition, a large amount of heat is released during the acid leaching process, which can also reduce heating costs. Controlling the amount of concentrated sulfuric acid, leaching temperature and time within an appropriate range can improve the leaching efficiency. When the amount of concentrated sulfuric acid is too low, the metals in the nickel-cobalt hydroxide cannot be fully leached. When the amount of concentrated sulfuric acid is too high, the residual acid concentration in the leachate is too high, affecting the extraction efficiency of scandium copper and increasing the cost of adjusting pH before the copper extraction process. In the acid leaching process, if the leaching temperature is too low, saturated nickel-cobalt precipitation will occur, reducing the saturated capacity of nickel-cobalt. If the leaching temperature is too high, the production cost will increase. If the leaching time is too short, the leaching efficiency of nickel-cobalt will decrease.

[0011] As a preferred solution, the mass concentration of the concentrated sulfuric acid is not less than 98%.

[0012] As a preferred solution, the pH value is adjusted to 5.0-6.0. Controlling the pH of the leaching solution within this range can ensure that scandium and copper are fully precipitated and separated from the solution, while nickel and cobalt still exist in the solution in ionic form.

[0013] As a preferred solution, alkali is used as the pH adjuster.

[0014] As a preferred solution, the alkali includes at least one of limestone slurry, sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate.

[0015] As a preferred solution, the nickel-cobalt purified solution is used to prepare nickel sulfate, cobalt sulfate, electrolytic nickel, electrolytic cobalt and other products.

[0016] As a preferred solution, the extraction and separation process is:

[0017] When the scandium concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and the copper concentration is not less than 7.5 g / L, a first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, the extract residue I is extracted and separated by a second extractant to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, the extract residue II is used to precipitate the remaining scandium and copper by adjusting the pH, and the precipitated residue II containing scandium and copper is returned to the acid leaching process;

[0018] When the scandium concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and the copper concentration is less than 7.5 g / L, a first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, and the extract residue I is directly returned to the acid leaching process until the copper concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 7.5 g / L, and then a second extractant is used for extraction and separation to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, and the extract residue II is used to precipitate the remaining scandium copper by adjusting the pH to obtain a precipitated residue II containing scandium copper and return it to the acid leaching process;

[0019] When the concentration of copper in the nickel-cobalt leachate containing scandium and copper is not less than 7.5 g / L and the concentration of scandium is less than 1.5 g / L, the second extractant is directly used for extraction and separation to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, the remaining scandium-copper is precipitated in the extract residue II by adjusting the pH, and the precipitate residue II containing scandium-copper is obtained and returned to the acid leaching process until the concentration of scandium in the nickel-cobalt leachate containing scandium and copper is not less than 1.5 g / L, and then the first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, and the extract residue I is returned to the acid leaching process.

[0020] The raffinate II obtained in the copper extraction and separation process is precipitated to separate the precipitate residue containing scandium copper and the like, thereby obtaining a high-purity nickel-cobalt solution.

[0021] Before using the second extractant to extract and separate copper, the pH of the raffinate I is adjusted to 2-3 by a pH adjuster. The pH adjuster includes at least one of nickel-cobalt hydroxide raw materials, limestone slurry, sodium hydroxide, ammonia water, sodium carbonate, and sodium bicarbonate.

[0022] As a preferred embodiment, the first extractant includes an organic phosphorus extractant and / or an organic carboxylic acid extractant.

[0023] As a preferred solution, the organophosphorus extractant includes at least one of P204, P507, and C272.

[0024] As a preferred embodiment, the organic carboxylic acid extractant includes CA-12 and / or cyclohexane acid.

[0025] As a preferred solution, the mass concentration of the first extractant is 10% to 30%, the extraction phase ratio O / A is 1:1 to 3. The extraction temperature is 30°C to 80°C, the extraction time is 5 to 10 minutes, and the extraction level is 1 to 3.

[0026] As a preferred solution, the first stripping agent includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, and ammonia water.

[0027] As a preferred solution, the concentration of the first stripping agent is 2 mol / L to 5 mol / L, the stripping phase ratio O / A is 1:0.5 to 3. The stripping temperature is 50°C to 80°C, the stripping time is 5 to 10 min, and the stripping stage is 1 to 3.

[0028] As a preferred solution, the second extractant includes at least one of LIX984, N902, and ZJ988.

[0029] As a preferred solution, the mass concentration of the second extractant is 10% to 30%, the extraction phase ratio O / A is 1:1 to 3. The extraction temperature is 30°C to 80°C, the extraction time is 5 to 10 minutes, and the extraction level is 1 to 3.

[0030] As a preferred solution, the second stripping agent includes at least one of sulfuric acid, hydrochloric acid and nitric acid. The concentration of the second stripping agent is 2moL / L to 4moL / L, and the stripping ratio O / A is 1:1 to 3. The stripping temperature is 30°C to 50°C, the stripping time is 5 to 10 minutes, and the stripping level is 1 to 3.

[0031] As a preferred solution, after the copper is extracted and separated by the second extractant, the raffinate is adjusted to a pH value of 5 to 6 to obtain a precipitate containing scandium copper. The precipitate is also returned to the acid leaching process for enriching scandium copper. The process uses an alkali as a pH regulator. The alkali includes at least one of a nickel-cobalt hydroxide raw material, a limestone slurry, sodium hydroxide, ammonia water, sodium carbonate, and sodium bicarbonate.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention realizes the stepwise separation and recovery of manganese, scandium, copper and nickel and cobalt elements through the steps of acid leaching-neutralization and pH adjustment-extraction and separation, effectively separates and purifies each metal element from nickel and cobalt hydroxide, improves the comprehensive utilization rate of laterite nickel ore, reduces the cost of raw materials, and has significant economic benefits and environmental protection value;

[0034] (2) The separation recovery rate of metal elements is high and the product purity is high. Among them, the recovery rates of manganese, scandium and copper elements are all above 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 This is a process flow chart of Example 1 of the present invention.

[0037] Figure 2 This is the process flow chart of Comparative Example 1. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] The present embodiment provides a method for comprehensively recovering metals from nickel-cobalt hydroxide. The mass contents of the components of nickel-cobalt hydroxide are shown in Table 1, wherein the scandium content is 0.06%, the copper content is 0.30%, and the manganese content is 5.83%.

[0041] Table 1 Composition mass content of nickel cobalt hydroxide (%)

[0042]

[0043] A method for comprehensively recovering metals from nickel-cobalt hydroxide in this embodiment specifically comprises the following steps:

[0044] (1) The nickel-cobalt hydroxide precipitate was acid-leached using concentrated sulfuric acid with a mass concentration of 98%, the amount of concentrated sulfuric acid used was 2 t / tNi, and the acid concentration in the solution after the leaching was controlled to be 40 g / L, the leaching temperature was 90°C, and the leaching time was 3 h.

[0045] (2) The acid leaching solution containing scandium and copper is neutralized with sodium hydroxide to adjust the pH value to 5.0. After the scandium and copper are completely precipitated, the solution is filtered to obtain a neutralized slag 1 (precipitated slag 1) and a purified nickel-cobalt solution 1. The neutralized slag 1 is continuously returned to the acid leaching process to enrich the scandium and copper.

[0046] The contents of various metal elements in the nickel-cobalt leaching solution after scandium copper enrichment are shown in Table 2. The acid leaching process preliminarily purifies and enriches the manganese element in the nickel-cobalt hydroxide. The obtained manganese-rich acid leaching residue is subjected to filter pressing treatment to obtain a filter cake with a manganese content of up to 53.748% as shown in Table 3. The filter cake can be directly sold as a manganese concentrate or used as a raw material for deep purification.

[0047] Table 2 Content of acid leaching solution after enrichment of scandium copper (g / L)

[0048]

[0049] Table 3 Composition mass content of acid leaching residue (%)

[0050]

[0051] (3) When the scandium ion content in the scandium copper-containing acid leaching solution (nickel-cobalt leaching solution after scandium copper enrichment) reaches 1.59 g / L and the copper ion concentration reaches 7.93 g / L, P507 is used as an extractant, sulfonated kerosene is used as a diluent for a first-level extraction, 20% of the P507 organic phase is configured, the extraction phase ratio O / A is 1:2, the extraction temperature is 70°C, the extraction time is 8 min, the extraction level is 1, and 99.8% of the scandium ions in the acid leaching solution are extracted into the organic phase. Then, liquid alkali (sodium hydroxide solution) is used as a stripping agent for a first-level stripping, the concentration of the liquid alkali is 4 mol / L, the stripping phase ratio O / A is 1:1, the stripping temperature is 70°C, and the stripping time is 7 min. The scandium in the organic phase loaded with P507 is completely precipitated into the aqueous phase in the form of crude scandium hydroxide. This crude scandium hydroxide product can be sold directly or used as a raw material for further purification. Among them, the composition content of the crude Sc(OH)3 product is shown in Table 4, the scandium content is 37.488%, and the scandium recovery rate is 99.7%.

[0052] Table 4 Crude Sc(OH)3 product composition mass content (%)

[0053]

[0054] (4) For the raffinate 1 after P507 extraction, the pH value was first adjusted to 3 with 20% limestone slurry, and then LIX984 was used as the extractant, and sulfonated kerosene was used as the diluent for two-stage countercurrent extraction. 20% of LIX984 organic phase was configured, the extraction phase ratio O / A was 1:2, the extraction temperature was 30°C, and the extraction time was 8 minutes. 99.3% of the copper ions in the raffinate 1 after P507 extraction were extracted into LIX984. The copper in the organic phase loaded with LIX984 was subjected to two-stage stripping with sulfuric acid as the stripping agent. The concentration of sulfuric acid was 2 mol / L, the stripping phase ratio O / A was 1:1, the stripping temperature was 30°C, and the stripping time was 7 minutes to obtain a copper sulfate solution. After evaporation and crystallization, the solution can be directly sold or further processed into cathode copper products. Among them, the copper recovery rate is 99.2%, and the purity of cathode copper can reach 99.95%.

[0055] (5) The raffinate 2 after LIX984 extraction is adjusted to pH 5.5 with nickel-cobalt hydroxide to neutralize the remaining scandium and copper and remove impurities such as iron and aluminum, and filtered to obtain neutralized slag 2 (precipitated slag 2) and purified nickel-cobalt solution 2. The neutralized slag 2 is combined with the above-mentioned neutralized slag 1 and returned to the acid leaching stage, while the purified nickel-cobalt solution 2 and the above-mentioned purified nickel-cobalt solution 1 can be finely filtered and finally sent to the refining workshop to be converted into products such as nickel sulfate, cobalt sulfate, electrolytic nickel and electrolytic cobalt.

[0056] The neutralized slag 1 in step (2) and the neutralized slag 2 in step (5) were combined to detect their metal element contents. The results are shown in Table 5.

[0057] Table 5 Composition and mass content of neutralized slag (%)

[0058]

[0059] Example 2

[0060] The composition contents of the nickel-cobalt hydroxide of this embodiment are shown in Table 6, wherein the scandium content is 0.053%, the copper content is 0.344%, and the manganese content is 5.981%.

[0061] Table 6 Composition mass content of nickel cobalt hydroxide (%)

[0062]

[0063] A method for comprehensively recovering metals from nickel-cobalt hydroxide in this embodiment specifically comprises the following steps:

[0064] (1) The nickel-cobalt hydroxide precipitate was acid-leached using concentrated sulfuric acid with a mass concentration of 98%, the amount of concentrated sulfuric acid used was 2 t / tNi, and the acid concentration in the solution after the leaching was controlled to be 40 g / L, the leaching temperature was 90°C, and the leaching time was 3 h.

[0065] (2) The acid leaching solution containing scandium and copper is neutralized with sodium hydroxide to adjust the pH value to 5.0. After the scandium and copper are completely precipitated, the solution is filtered to obtain a neutralized slag 1 (precipitated slag 1) and a purified nickel-cobalt solution 1. The neutralized slag 1 is continuously returned to the acid leaching process to enrich the scandium and copper.

[0066] The contents of various metal elements in the nickel-cobalt leaching solution after scandium copper enrichment are shown in Table 7. The acid leaching process preliminarily purifies and enriches the manganese element in the nickel-cobalt hydroxide. The obtained manganese-rich acid leaching residue is subjected to filter pressing treatment to obtain a filter cake with a manganese content of up to 52.15% as shown in Table 8. The filter cake can be directly sold as a manganese concentrate or used as a raw material for deep purification.

[0067] Table 7 Content of acid leaching solution after enrichment of scandium copper (g / L)

[0068]

[0069] Table 8 Composition mass content of acid leaching residue (%)

[0070]

[0071] (3) When the copper ion concentration in the scandium copper-containing acid leaching solution (nickel-cobalt leaching solution after scandium copper enrichment) is 7.63 g / L and the scandium ion content is less than 1.5 g / L, copper extraction and separation is first performed, that is, the acid leaching solution after scandium copper enrichment is first adjusted to pH 2.5 with 20% limestone slurry, and then ZJ988 is used as the extractant, sulfonated kerosene is used as the diluent, and three-stage countercurrent extraction is performed, 25% of ZJ988 organic phase is configured, the extraction phase ratio O / A is 1:1, the extraction temperature is 30°C, and the extraction After 8 minutes, 99.3% of the copper ions in the acid leaching solution were extracted into ZJ988. ZJ988 loaded with copper organic was then stripped using sulfuric acid as a stripping agent for secondary stripping. The concentration of sulfuric acid was 3 mol / L, the stripping ratio O / A was 1:1, the stripping temperature was 30°C, and the stripping time was 7 minutes to obtain a copper sulfate solution. After evaporation and crystallization, the solution can be directly sold or further processed into a cathode copper product. The copper recovery rate was 99.1% and the cathode copper purity was 99.95%.

[0072] (4) The raffinate 2 after LIX984 extraction is adjusted to pH 5.5 with nickel-cobalt hydroxide to precipitate scandium and remove impurities such as iron and aluminum, and filtered to obtain neutralized slag 2 (precipitated slag 2) and purified nickel-cobalt solution 2. The neutralized slag 2 is combined with the above-mentioned neutralized slag 1 and returned to the acid leaching stage to continue to enrich scandium copper until the scandium ion concentration in the acid leaching solution reaches 1.5 g / L or more, and then the scandium is extracted and separated, that is, P507 is used as the extractant, sulfonated kerosene is used as the diluent for the first-level extraction, 20% of the P507 organic phase is prepared, the extraction phase O / A ratio is 1:2, the extraction temperature is 70°C, the extraction time is 8 minutes, the extraction level is 1, and 99.8% of the scandium in the acid leaching solution is separated. The scandium in the organic phase loaded with P507 is completely precipitated into the aqueous phase in the form of crude scandium hydroxide. The composition and content of the crude scandium hydroxide product are shown in Table 9. It can be sold directly or used as a raw material for further purification. The scandium recovery rate is 99.6%.

[0073] Table 9 Crude Sc(OH)3 product composition mass content (%)

[0074]

[0075] The purified nickel-cobalt solution 2 and the purified nickel-cobalt solution 1 can both be finely filtered and finally sent to a refining workshop to be converted into products such as nickel sulfate, cobalt sulfate, electrolytic nickel and electrolytic cobalt.

[0076] The neutralized slag 1 in step (2) and the neutralized slag 2 in step (4) were combined to detect their metal element contents. The results are shown in Table 10.

[0077] Table 10 Composition mass content of neutralized slag (%)

[0078]

[0079] Example 3

[0080] The composition contents of the nickel-cobalt hydroxide of this embodiment are shown in Table 11, wherein the scandium content is 0.076%, the copper content is 0.208%, and the manganese content is 4.87%.

[0081] Table 11 Composition mass content of nickel cobalt hydroxide (%)

[0082]

[0083] A method for comprehensively recovering metals from nickel-cobalt hydroxide in this embodiment specifically comprises the following steps:

[0084] (1) The nickel-cobalt hydroxide precipitate was acid-leached using concentrated sulfuric acid with a mass concentration of 98%, the amount of concentrated sulfuric acid used was 2 t / tNi, and the acid concentration in the solution after the leaching was controlled to be 40 g / L, the leaching temperature was 90°C, and the leaching time was 3 h.

[0085] (2) The acid leaching solution containing scandium and copper is neutralized with sodium hydroxide to adjust the pH value to 5.0. After the scandium and copper are completely precipitated, the solution is filtered to obtain a neutralized slag 1 (precipitated slag 1) and a purified nickel-cobalt solution 1. The neutralized slag 1 is continuously returned to the acid leaching process to enrich the scandium and copper.

[0086] The contents of various metal elements in the nickel-cobalt leaching solution after scandium copper enrichment are shown in Table 12. The acid leaching process preliminarily purifies and enriches the manganese element in the nickel-cobalt hydroxide, and the obtained manganese-rich acid leaching residue is subjected to filter pressing treatment to obtain a filter cake with a manganese content of up to 52.46% as shown in Table 13. The filter cake can be directly sold as a manganese concentrate or used as a raw material for deep purification.

[0087] Table 12 Content of components in the acid leaching solution after enrichment of scandium copper (g / L)

[0088]

[0089] Table 13 Composition mass content of acid leaching residue (%)

[0090]

[0091] (3) When the scandium ion concentration in the scandium copper-containing acid leaching solution (nickel-cobalt leaching solution after scandium copper enrichment) reaches 1.62 g / L and the copper ion content does not reach 7.5 g / L, scandium is extracted and separated, that is, P507 is used as the extractant, sulfonated kerosene is used as the diluent for the first-level extraction, 20% of the P507 organic phase is configured, the extraction phase O / A ratio is 1:2, the extraction temperature is 70°C, the extraction time is 8 min, the extraction level is 1, 99.8% of the scandium ions in the acid leaching solution are extracted into the organic phase, and then liquid alkali (sodium hydroxide solution) is used as the stripping agent for the first-level stripping, the concentration of the liquid alkali is 4 mol / L, the stripping phase O / A ratio is 1:1, the stripping temperature is 70°C, and the stripping time is 7 min. The scandium in the P507-loaded organic phase is completely precipitated into the aqueous phase in the form of crude scandium hydroxide. This crude scandium hydroxide product can be sold directly or used as a raw material for further purification. Among them, the composition content of the crude Sc(OH)3 product is shown in Table 14, the scandium content is 39.41%, and the scandium recovery rate is 99.7%.

[0092] Table 14 Crude Sc(OH)3 product composition mass content (%)

[0093]

[0094] (4) The raffinate 1 after P507 extraction is adjusted to pH 5.5 with nickel-cobalt hydroxide to precipitate copper and remove impurities such as iron and aluminum, and filtered to obtain neutralized slag 2 (precipitated slag 2) and purified nickel-cobalt solution 2. The neutralized slag 2 is combined with the above neutralized slag 1 and returned to the acid leaching stage to continue to enrich scandium copper until the copper ion concentration in the acid leaching solution reaches 7.5 g / L or more, and then copper extraction and separation is performed, that is, first using 20% ​​limestone slurry to adjust the pH to 3, then using LIX984 as the extractant, using sulfonated kerosene as the diluent for two-stage countercurrent extraction, configuring 20% ​​LIX984 organic phase, extracting phase O / A ratio of 1:2, extraction temperature of 30°C, extraction time of 8 min, 99.3% of copper ions in the acid leaching solution are extracted into LIX984. The copper in the organic layer loaded by LIX984 is stripped in two stages using sulfuric acid as the stripping agent. The concentration of sulfuric acid is 2 mol / L, the stripping ratio O / A is 1:1, the stripping temperature is 30°C, and the stripping time is 7 minutes to obtain a copper sulfate solution. After evaporation and crystallization, the solution can be directly sold or further processed into cathode copper products. It is calculated that the copper recovery rate is 99.2% and the purity of the cathode copper can reach 99.95%.

[0095] The purified nickel-cobalt solution 2 and the purified nickel-cobalt solution 1 can both be finely filtered and finally sent to a refining workshop to be converted into products such as nickel sulfate, cobalt sulfate, electrolytic nickel and electrolytic cobalt.

[0096] The neutralized slag 1 in step (2) and the neutralized slag 2 in step (4) were combined to detect their metal element content. The results are shown in Table 15.

[0097] Table 15 Composition and mass content of neutralized slag (%)

[0098]

[0099] Comparative Example 1

[0100] This comparative example is an existing nickel cobalt hydroxide treatment method, such as Figure 2 As shown, the process comprises the following steps: leaching the nickel-cobalt hydroxide precipitate with sulfuric acid to obtain a nickel-cobalt leaching solution containing scandium and copper, and an acid leaching residue rich in manganese; the leaching residue is returned to the CCD countercurrent washing link of the high-pressure acid leaching process, and finally discharged in the form of wet slag.

[0101] In this comparative example, the acid leaching liquid after sulfuric acid leaching is further pre-neutralized. The alkali required for pre-neutralization comes from the neutralization leaching filtrate and limestone slurry. The pH is adjusted to 5.2, and the obtained pre-neutralization slag is returned to the CCD countercurrent washing link of the high-pressure acid leaching process. The purified nickel-cobalt solution is finely filtered and finally sent to the refining workshop to be converted into products such as nickel sulfate, cobalt sulfate, electrolytic nickel and electrolytic cobalt. The filter residue produced by fine filtration is added to limestone slurry to continue neutralization leaching to remove iron, aluminum, scandium, copper, etc. The filtrate produced by neutralization leaching is returned to the pre-neutralization stage, and the filter cake is returned to the circulating leaching stage of high-pressure acid leaching, and finally discharged in the form of wet slag (scandium and copper are not recovered).

[0102] According to 40000t Ni / a of MHP production, compared with the comparative example, Example 1 achieves efficient and comprehensive recovery of valuable metals such as scandium, copper, and manganese from nickel-cobalt hydroxide without affecting the production capacity of nickel and cobalt, wherein about 2924tMn / a of manganese concentrate by-product is recovered, about 300tCu / a of copper sulfate by-product is recovered, and about 76.6t of crude scandium hydroxide by-product is recovered. Sc / a, significantly optimize resource utilization and improve economic benefits.

[0103] Comparative Example 2

[0104] A method for comprehensive recovery of metals from nickel-cobalt hydroxides, specifically comprising the following steps:

[0105] The nickel-cobalt hydroxide precipitate is leached with concentrated sulfuric acid having a mass concentration of 98% to obtain a nickel-cobalt leaching solution containing scandium and copper as shown in Table 16, and an acid leaching residue rich in manganese. This process preliminarily purifies and enriches the manganese element in the nickel-cobalt hydroxide.

[0106] In this comparative example, after sulfuric acid leaching treatment, the scandium ion content in the obtained acid leaching solution is only 0.19g / L, and the copper ion concentration is also relatively low, at 0.28g / L. As a comparative example, we did not adopt the cyclic enrichment scheme of scandium and copper, but directly entered the extraction process: first, the first extractant was used to extract scandium, and the scandium was separated by the first stripping agent; then the copper was extracted by the second extractant, and the copper was separated by the second stripping agent.

[0107] This comparative example can only recover up to 80% of the scandium copper precipitate in the acid leaching solution. However, this direct and continuous extraction and separation technical route not only requires continuous operation investment, thereby increasing labor costs, but also has a lower concentration of scandium and copper ions than Example 1. During the extraction process, more nickel, cobalt, etc. enter the organic phase, which reduces the purity of the crude scandium hydroxide, as shown in Table 17. Therefore, the economy of the entire recovery process is not good.

[0108] Table 16 Acid leaching liquid component content (g / L)

[0109]

[0110] Table 17 Crude Sc(OH)3 Product Composition Mass Content (%)

[0111]

[0112] Comparative Example 3

[0113] A method for comprehensive recovery of metals from nickel-cobalt hydroxides, specifically comprising the following steps:

[0114] (1) The nickel-cobalt hydroxide precipitate was acid-leached using concentrated sulfuric acid with a mass concentration of 98%, the amount of concentrated sulfuric acid used was 2 t / tNi, and the acid concentration in the solution after the leaching was controlled to be 40 g / L, the leaching temperature was 90°C, and the leaching time was 3 h.

[0115] (2) The scandium copper-containing acid leaching solution was neutralized with sodium hydroxide to adjust the pH value to 5.0, and filtered to directly obtain neutralized slag 1 (precipitated slag 1) and a purified nickel-cobalt solution, wherein the neutralized slag 1 was not returned to the acid leaching process for the enrichment of scandium and copper. The components of the scandium copper-containing acid leaching solution are shown in Table 18, and the purified nickel-cobalt solution is shown in Table 19.

[0116] Table 18 Acid leaching liquid component content (g / L)

[0117]

[0118] Table 19 Content of purified nickel-cobalt solution (g / L)

[0119]

[0120] In this comparative example, at most 85% of the scandium and copper in the acid leaching solution can be precipitated and recovered, and 28.8% of the nickel is also precipitated in this process. At the same time, both scandium and copper are precipitated and difficult to separate. Compared with Example 1, this scheme can only enrich scandium and copper, and cannot achieve a good separation and recovery effect.

[0121] Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese, characterized in that: A nickel-cobalt hydroxide containing scandium, copper and manganese is subjected to acid leaching to obtain a nickel-cobalt leaching solution containing scandium and copper and a leaching residue containing manganese. The nickel-cobalt leaching solution containing scandium and copper is subjected to pH adjustment to precipitate scandium-copper to obtain a precipitated residue I containing scandium-copper and a nickel-cobalt purified solution. The precipitated residue I containing scandium-copper is returned to the acid leaching process until the concentration of scandium in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and / or the concentration of copper is not less than 7.5 g / L, and then the scandium and copper are respectively recovered by extraction and separation, wherein the raffinate I obtained in the scandium extraction and separation process is directly returned to the acid leaching process or copper extraction and separation is continued; the raffinate II obtained in the copper extraction and separation process is subjected to pH adjustment to precipitate the remaining scandium-copper to obtain a precipitated residue II containing scandium-copper and returned to the acid leaching process.

2. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 1, characterized in that: The mass content of scandium element in the nickel-cobalt hydroxide containing scandium, copper and manganese is not higher than 0.1%, and the mass content of copper element is not higher than 0.5%.

3. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 1 or 2, characterized in that: The acid leaching conditions are as follows: concentrated sulfuric acid is used as a leaching agent, the amount of the leaching agent relative to the nickel element in the nickel-cobalt hydroxide containing scandium, copper and manganese is 1.5-3 t / tNi, and the concentration of H2SO4 in the nickel-cobalt leaching solution containing scandium and copper is controlled to be 20-80 g / L; the leaching temperature is 60-110°C, and the leaching time is 0.5-4.5 h.

4. The method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 1, characterized in that: The pH value is adjusted to 5.0-6.

0.

5. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 1 or 4, characterized in that: A base is used as a pH adjuster.

6. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 5, characterized in that: The alkali includes at least one of nickel cobalt hydroxide raw materials, limestone slurry, sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate.

7. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 1, characterized in that: The extraction and separation process is as follows: when the scandium concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and the copper concentration is not less than 7.5 g / L, a first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, the extract residue I is extracted and separated by a second extractant to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, the extract residue II is used to precipitate the remaining scandium and copper by adjusting the pH, and the precipitated residue II containing scandium and copper is returned to the acid leaching process; When the scandium concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 1.5 g / L and the copper concentration is less than 7.5 g / L, a first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, and the extract residue I is directly returned to the acid leaching process until the copper concentration in the nickel-cobalt leaching solution containing scandium and copper is not less than 7.5 g / L, and then a second extractant is used for extraction and separation to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, and the extract residue II is used to precipitate the remaining scandium copper by adjusting the pH to obtain a precipitated residue II containing scandium copper and return it to the acid leaching process; When the concentration of copper in the nickel-cobalt leachate containing scandium and copper is not less than 7.5 g / L and the concentration of scandium is less than 1.5 g / L, the second extractant is directly used for extraction and separation to obtain a copper-containing organic phase and an extract residue II, the copper-containing organic phase is extracted and separated by a second stripping agent, the remaining scandium-copper is precipitated in the extract residue II by adjusting the pH, and the precipitate residue II containing scandium-copper is obtained and returned to the acid leaching process until the concentration of scandium in the nickel-cobalt leachate containing scandium and copper is not less than 1.5 g / L, and then the first extractant is used for extraction and separation to obtain a scandium-containing organic phase and an extract residue I, the scandium-containing organic phase is extracted and separated by a first stripping agent, and the extract residue I is returned to the acid leaching process.

8. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 7, characterized in that: The first extractant includes an organic phosphorus extractant and / or an organic carboxylic acid extractant; the first stripping agent includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, and ammonia water.

9. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 8, characterized in that: The organophosphorus extractant includes at least one of P204, P507, and C272; The organic carboxylic acid extractant includes CA-12 and / or cyclohexane acid.

10. A method for comprehensive recovery of metals from nickel-cobalt hydroxide containing scandium, copper and manganese according to claim 7, 8 or 9, characterized in that: The second extracting agent includes at least one of LIX984, N902, and ZJ988; the second stripping agent includes at least one of sulfuric acid, hydrochloric acid, and nitric acid.

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