Method for extracting nickel resource from laterite-nickel ore acid leaching residue

Abstract

The invention discloses a method for extracting nickel resources from laterite-nickel ore acid leaching residues, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: mixing laterite-nickel ore acid leaching residues, metal chloride and an alkali solution, and carrying out a hydrothermal reaction to obtain a hydrothermal sample; washing and drying the hydrothermal sample to obtain a washing product; and the washing product is subjected to acid leaching, a leaching solution and alkaline metal oxide are mixed for a reaction, and the nanoscale nickel hydroxide material is obtained. According to the method, nickel metal resources in the laterite-nickel ore acid leaching residues can be efficiently recycled, and the nickel metal resources are applied as materials.

Description

Technical Field

[0001] The invention relates to a method for extracting nickel resources from acid leaching residues of laterite nickel ore, belonging to the technical field of hydrometallurgy. Background Art

[0002] Nickel is a key metal with a strategic position. Its excellent plasticity, corrosion resistance and chemical stability make it an important raw material for nickel-based alloys, electroplating and new energy batteries. With the rapid development of the electroplating industry and the new energy field, the supply of nickel has become tighter year by year, which means that laterite nickel ore with large reserves and relatively low mining costs has become the main raw material for nickel production.

[0003] There are two main smelting processes for laterite nickel ore: pyrometallurgy and hydrometallurgy. For high-nickel, low-magnesium-silicon laterite nickel ore, the rotary kiln roasting-electric furnace smelting process is mainly used; for limonite laterite nickel ore with low nickel content, the pressurized acid leaching process is more efficient.

[0004] The grade of laterite nickel ore is relatively low, so pressurized acid leaching is the mainstream direction of wet nickel extraction. This process will produce a lot of solid waste. According to statistics, the production of 1 ton of metal products will be accompanied by 200 tons of slag. With the commissioning of a large number of laterite nickel ore wet process projects, the discharge of laterite nickel ore acid leaching slag is increasing. Laterite nickel ore acid leaching slag still contains a large amount of valuable elements such as nickel, iron, chromium, magnesium, aluminum, rare earth, etc., which is a valuable secondary mineral resource.

[0005] Due to the limited technical approaches for comprehensive utilization of laterite nickel ore acid leaching residues (currently the main disposal methods are stacking, deep sea landfill or underground filter press backfill), the utilization rate of these nickel slags is extremely low. Therefore, it is urgent to develop a method for directional extraction of nickel resources from acid leaching residues.

[0006] A Chinese patent (publication number CN 116240381 A) discloses a method for comprehensive utilization of laterite nickel ore leaching residue, which comprises the following steps: S1: acid leaching the laterite nickel ore leaching residue to be treated with acid 1, and obtaining leaching residue and leaching solution after solid-liquid separation; S2: adding nano Fe3O4 seeds and additive 1 to the leaching solution obtained in step S1, adding acid 2 to adjust the pH of the mixed solution to 0-2, and performing hydrothermal reaction. After the reaction is completed, the obtained product is simultaneously subjected to ultrasonic and magnetic separation, and the obtained non-magnetic solution is subjected to solid-liquid separation to obtain filter residue 1 and filtrate 1; S3: concentrating the filtrate 1 obtained in step S2, adding alkali to adjust the pH of the concentrated solution to 7-12, and separating to obtain nickel salt. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide a method for extracting nickel resources from laterite nickel ore acid leaching residue, which can efficiently recycle the nickel metal resources in the laterite nickel ore acid leaching residue and apply them as materials.

[0008] In order to achieve the above object, the first aspect of the present invention is to provide a method for extracting nickel resources from laterite nickel ore acid leaching residue, the method comprising: (1) mixing laterite nickel ore acid leaching residue, metal chloride and alkaline solution and subjecting the mixture to a hydrothermal reaction to obtain a hydrothermal sample; (2) washing the hydrothermal sample with water and drying it to obtain a washed product; (3) The water-washed product is subjected to acid leaching, and the leaching solution is mixed with an alkaline metal oxide to obtain a nano-scale nickel hydroxide material.

[0009] Since the content of metallic nickel in the acid leaching residue of laterite nickel ore is extremely low, it is difficult to efficiently extract nickel resources in the acid leaching residue of laterite nickel ore by conventional methods. The innovation of the present invention is that the acid leaching residue of laterite nickel ore is first mixed with metal chloride and alkaline solution and then subjected to hydrothermal reaction to precipitate nickel element and directionally convert it into nickel ferrite solid, and then the hydrothermal sample obtained by the hydrothermal reaction is washed with water to enrich the metallic nickel and effectively separate it from other impurities, and then the washed sample is acid leached, and the leachate is mixed with alkaline metal oxide to obtain nano-scale nickel hydroxide material.

[0010] It should be noted that the laterite nickel ore acid leaching residue described in the present invention comes from the hydrometallurgical process of laterite nickel ore, in which acidic substances such as sulfuric acid are used to leach the ore to extract valuable metal elements such as nickel and magnesium. The nickel, magnesium and other elements in the ore are dissolved into the solution, while the undissolved part remains in the form of slag to form laterite nickel ore acid leaching residue.

[0011] In a preferred embodiment, the method further comprises, in step (1), first drying, grinding and sieving the laterite nickel ore acid leaching residue, and then mixing the sieved laterite nickel ore acid leaching residue with metal chloride and alkaline solution to carry out a hydrothermal reaction.

[0012] In a preferred embodiment, the particle size of the sieved laterite nickel ore acid leaching residue is ≤75 μm.

[0013] In a preferred embodiment, the metal chloride is selected from at least one of potassium chloride, sodium chloride and ferric chloride.

[0014] In a preferred embodiment, the alkaline solution is a sodium hydroxide solution and / or a potassium hydroxide solution.

[0015] In a preferred embodiment, the type and amount of the metal chloride are controlled so that at the start of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:1.5~5. Too low iron ion concentration will lead to excess nickel ions and cause nickel ion loss; too high iron ion concentration will accelerate the corrosion of the metal matrix and cause the adhesion of deposits.

[0016] In a preferred embodiment, the solid-to-liquid ratio of the total mass of the laterite nickel ore acid leaching residue and the metal chloride to the alkaline solution is 150-260 g / L.

[0017] In a preferred embodiment, the concentration of the alkaline solution is 1.5-3 mol / L.

[0018] In a preferred embodiment, the temperature of the hydrothermal reaction is 150-220°C and the time is 6-24 h.

[0019] In the preferred embodiment, the alkaline metal oxide is calcium oxide. First, calcium oxide can adjust the pH value. Part of the calcium oxide participates in the formation of nickel hydroxide precipitation, and the remaining calcium oxide that does not participate in the reaction can increase the pH value of the solution. After calcium oxide is added to the acid leaching solution of nickel ferrite, the pH value of the solution increases, which is conducive to the precipitation reaction. Second, it promotes the precipitation reaction: as the pH value increases, the nickel ions (Ni 2+ ) will react with hydroxide ions (OH - ) reacts to form nickel hydroxide. In this process, Ni 2+ With OH - A precipitate of Ni(OH)2 is formed and thus separated from the solution.

[0020] In a preferred embodiment, in step (2), the drying conditions include: a temperature of 40-70° C. and a time of 1-8 hours.

[0021] In a preferred embodiment, in step (3), a hydrochloric acid solution with a concentration of 1 to 8 mol / L is used for acid leaching, the solid-liquid ratio of the acid leaching is 30 to 70 g / L, the acid leaching time is 2 to 6 hours, and the mixing reaction time is 5 to 10 hours.

[0022] In a preferred embodiment, the amount of the basic metal oxide used accounts for 10-50wt% of the water-washed product.

[0023] In a preferred embodiment, the leachate is first diluted 2 to 10 times with deionized water and then mixed with the alkaline metal oxide. Diluting the leachate is beneficial to reducing the impurity concentration and improving the selection efficiency of nickel ions.

[0024] In a preferred embodiment, the mixing reaction is carried out under stirring conditions. The present invention has no special requirements for the stirring conditions, and any conditions known in the art can be used.

[0025] In a preferred embodiment, the mixture obtained after the mixing reaction is centrifuged or filtered, and the solid matter obtained by centrifugation or filtration is dried at 50-70° C. for 1-5 hours to obtain the nano-scale nickel hydroxide material.

[0026] The present invention illustratively provides a process flow chart of Example 1.

[0027] Compared with the prior art, the present invention has at least the following advantages: (1) The present invention aims at the directional extraction of nickel metal resources from the acid leaching residue of laterite nickel ore. The acid leaching residue and metal chloride are hydrothermally treated in an alkaline solution to directionally transform nickel into nickel ferrite solid. After washing with deionized water, the metallic nickel is enriched and effectively separated from other impurities.

[0028] (2) Adding alkaline metal oxides to the nickel ferrite acid leaching solution can promote the conversion of nickel ferrite into nickel hydroxide. The produced nickel hydroxide material can be further purified as a ternary electrode material, realizing the high added value utilization of metallic nickel.

[0029] (3) The nickel extraction method provided by the present invention has high extraction efficiency and high selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the method for extracting nickel resources from acid leaching residue of laterite nickel ore in Example 1. DETAILED DESCRIPTION

[0031] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0032] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by professionals in this field without creative work still belong to the protection scope of the present invention.

[0033] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0034] In the following examples, Ni 2+ and Fe 3+ The content of Fe in solution was determined by conventional methods. 3+ The test method for the content is as follows: (1) Using an atomic absorption spectrometer to determine the Fe content in the solution 2+ The Fe 2+ Concentration 1; (2) Reduction of Fe by SnCl2 and TiCl3 3+, using atomic absorption spectrometer to determine the Fe 2+ The Fe content in the solution was determined by comparing the absorbance of 2+ The concentration of Fe in the solution is 2; (3) The difference between concentration 2 and concentration 1 is the concentration of Fe in the solution. 3+ The concentration of Ni in the solution 2+ The test method for the content of Ni is: using EDTA and Ni + A stable complex is formed, which is measured by titration.

[0035] Example 1 The contents of each element in the laterite nickel ore acid leaching residue in this embodiment are: Ni content is 6.58g / Kg, Co content is 0.07g / Kg, Fe content is 580.50g / Kg, Al content is 13.07g / Kg, Mn content is 0.83g / Kg, Mg content is 1.42g / Kg, Zn content is 0.13g / Kg, Ca content is 1.06g / Kg, Cu content is 0.05g / Kg, and Si content is 22.9g / Kg.

[0036] (1) 1000 g of laterite nickel ore acid leaching residue that had passed through a 200-mesh sieve was mixed with 200 g of sodium chloride, added into 6 L of 2 mol / L sodium hydroxide solution, and heated at 160 °C in a hydrothermal kettle for 10 h to obtain a hydrothermal sample; At the beginning of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:2; (2) After cooling, the mixture was washed with deionized water for three times and dried at 60 °C for 2 h to obtain a washed product; (3) 25.68 g of the washed product was acid-leached with 500 ml of 3 mol / L dilute hydrochloric acid for 3 h. The leaching solution was diluted 5 times with water and mixed with 10 g of calcium oxide for reaction. The mixture was stirred for 5 h, centrifuged, and the solid was taken out and dried at 60 °C for 2 h to obtain nano-scale nickel hydroxide material.

[0037] Example 2 The contents of each element in the laterite nickel ore acid leaching residue in this embodiment are: Ni content is 7.54g / Kg, Co content is 0.07g / Kg, Fe content is 578.68g / Kg, Al content is 12.7g / Kg, Mn content is 0.80g / Kg, Mg content is 1.27g / Kg, Zn content is 0.11g / Kg, Ca content is 0.97g / Kg, Cu content is 0.03g / Kg, and Si content is 26.22g / Kg.

[0038] (1) 1500 g of laterite nickel ore acid leaching residue that had passed through a 200-mesh sieve was mixed with 400 g of sodium chloride, added into 9 L of 1.8 mol / L sodium hydroxide solution, and heated at 170 °C in a hydrothermal kettle for 8 h to obtain a hydrothermal sample; At the beginning of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:2.5; (2) After cooling, the mixture was washed with deionized water for 4 times and dried at 65 °C for 4 h to obtain a washed product; (3) 45.63 g of the washed product was acid-leached with 700 ml of 4 mol / L dilute hydrochloric acid for 4 h. The leaching solution was diluted 5 times with water and mixed with 15 g of calcium oxide for reaction. The mixture was stirred for 8 h, centrifuged, and the solid was taken out and dried at 60 °C for 3 h to obtain nano-scale nickel hydroxide material.

[0039] Example 3 The contents of each element in the laterite nickel ore acid leaching residue in this embodiment are: Ni content is 6.59 g / Kg, Co content is 0.07 g / Kg, Fe content is 576.90 g / Kg, Al content is 13.89 g / Kg, Mn content is 0.82 g / Kg, Mg content is 1.27 g / Kg, Zn content is 0.11 g / Kg, Ca content is 1.02 g / Kg, Cu content is 0.03 g / Kg, and Si content is 25.13 g / Kg.

[0040] (1) 1200 g of laterite nickel ore acid leaching residue that had passed through a 200-mesh sieve was mixed with 240 g of sodium chloride, added into 6.5 L of 2.1 mol / L sodium hydroxide solution, and heated at 180 °C in a hydrothermal kettle for 6 h to obtain a hydrothermal sample; At the beginning of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:1.5; (2) After cooling, the mixture was washed twice with deionized water and dried at 55 °C for 5 h to obtain a washed product; (3) 41.27 g of the washed product was acid-leached with 700 ml of 4 mol / L dilute hydrochloric acid for 4 h. The leaching solution was diluted 5 times with water and mixed with 12 g of calcium oxide for reaction. The mixture was stirred for 6 h, centrifuged, and the solid was taken out and dried at 60 °C for 2 h to obtain nano-scale nickel hydroxide material.

[0041] Example 4 The contents of each element in the laterite nickel ore acid leaching residue in this embodiment are: Ni content is 7.64 mg / Kg, Co content is 0.07 g / Kg, Fe content is 548.83 g / Kg, Al content is 16.6 g / Kg, Mn content is 0.80 g / Kg, Mg content is 1.54 g / Kg, Zn content is 0.13 g / Kg, Ca content is 0.71 g / Kg, Cu content is 0.04 g / Kg, and Si content is 24.78 g / Kg.

[0042] (1) 1000 g of laterite nickel ore acid leaching residue that had passed through a 200-mesh sieve was mixed with 220 g of sodium chloride, added into 7 L of 2.5 mol / L sodium hydroxide solution, and heated at 180 °C in a hydrothermal kettle for 7 h to obtain a hydrothermal sample; At the beginning of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:3; (2) After cooling, the mixture was washed with deionized water for three times and dried at 60 °C for 3 h to obtain a washed product; (3) 31.58 g of the washed product was acid-leached with 800 ml of 2.5 mol / L dilute hydrochloric acid for 2.5 h. The leaching solution was diluted 8 times with water and mixed with 9 g of calcium oxide for reaction. The mixture was stirred for 5 h, centrifuged, and the solid was taken out and dried at 60 °C for 2 h to obtain nano-scale nickel hydroxide material.

[0043] Example 5 The contents of each element in the laterite nickel ore acid leaching residue in this embodiment are: Ni content is 8.56 g / Kg, Co content is 0.07 g / Kg, Fe content is 572.58 g / Kg, Al content is 12.40 g / Kg, Mn content is 0.83 g / Kg, Mg content is 1.18 g / Kg, Zn content is 0.12 g / Kg, Ca content is 0.89 g / Kg, Cu content is 0.03 g / Kg, and Si content is 25.89 g / Kg.

[0044] (1) 1100 g of laterite nickel ore acid leaching residue that had passed through a 200-mesh sieve was mixed with 180 g of sodium chloride, added into 5 L of 1.8 mol / L sodium hydroxide solution, and heated at 180 °C in a hydrothermal kettle for 10 h to obtain a hydrothermal sample; At the beginning of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:5; (2) After cooling, the mixture was washed with deionized water for three times and dried at 60 °C for 3 h to obtain a washed product; (3) 28.88 g of the washed product was acid-leached with 900 ml of 3 mol / L dilute hydrochloric acid for 6 h. The leaching solution was diluted 6 times with water and mixed with 8 g of calcium oxide for reaction. The mixture was stirred for 5 h, centrifuged, and the solid was taken out and dried at 60 °C for 2 h to obtain nano-scale nickel hydroxide material.

[0045] Example 6 This example is carried out in a similar manner to that of Example 1, except that the metal chlorides added in step (1) are ferric chloride and sodium chloride, and the total amount of ferric chloride and sodium chloride added is 200 g. At the same time, the amount of ferric chloride is controlled so that at the start of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:6.

[0046] Comparative Example 1 This comparative example was carried out in a similar manner to Example 1, except that the calcium oxide in Example 1 was replaced with an equal mass of sodium carbonate.

[0047] Comparative Example 2 This comparative example was carried out in a similar manner to Example 1, except that the calcium oxide in Example 1 was replaced with an equal mass of calcium carbonate.

[0048] Test Case The direct recovery rate of nickel element, purity and particle size of nickel hydroxide in the above examples were tested, and the specific test results are shown in Table 1.

[0049] Among them, ICP-OES is used to test the nickel content in the nano-scale nickel hydroxide material, and the nickel direct yield is calculated by a formula; and the particle size is tested by a laser particle size analyzer.

[0050] Ni direct yield:

[0051] R : Direct yield; m 0 : Quality of acid leaching residue of laterite nickel ore; oh 0 : Ni content in laterite nickel ore acid leaching residue; m 1 : Nickel hydroxide material quality; oh 1 : Ni content in nickel hydroxide material.

[0052]

[0053] It can be seen from the above data that the extraction method of the present invention can efficiently recycle the nickel metal resources in the acid leaching residue of laterite nickel ore, and can also obtain a high-purity and nano-scale nickel hydroxide product.

[0054] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for extracting nickel resources from laterite nickel ore acid leaching residue, characterized in that: The method includes: (1) mixing the acid leaching residue of laterite nickel ore, metal chloride and alkaline solution and subjecting them to a hydrothermal reaction to obtain a hydrothermal sample; (2) washing the hydrothermal sample with water and drying it to obtain a washed product; (3) The water-washed product is subjected to acid leaching, and the leaching solution is mixed with an alkaline metal oxide for reaction to obtain a nano-scale nickel hydroxide material.

2. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to claim 1, characterized in that: The metal chloride is selected from at least one of potassium chloride, sodium chloride and ferric chloride; And / or, the alkaline solution is a sodium hydroxide solution and / or a potassium hydroxide solution.

3. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to claim 2, characterized in that: The type and amount of the metal chloride are controlled so that at the start of the hydrothermal reaction, Ni 2+ and Fe 3+ The molar ratio is 1:1.5~5.

4. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The solid-to-liquid ratio of the total mass of the laterite nickel ore acid leaching residue and the metal chloride to the alkaline solution is 150-260 g / L.

5. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The concentration of the alkaline solution is 1.5-3 mol / L.

6. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The temperature of the hydrothermal reaction is 150-220°C and the time is 6-24 h.

7. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The basic metal oxide is calcium oxide.

8. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: In step (3), a hydrochloric acid solution with a concentration of 1-8 mol / L is used for acid leaching, the solid-liquid ratio of the acid leaching is 30-70 g / L, the acid leaching time is 2-6 h, and the mixing reaction time is 5-10 h.

9. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The amount of the basic metal oxide used accounts for 10-50wt% of the water-washed product.

10. A method for extracting nickel resources from laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The leaching solution is diluted 2 to 10 times with deionized water and then mixed with the alkaline metal oxide.

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