Resource utilization method for high-pressure acid leaching residue of laterite nickel ore

Abstract

Provided in the present application is a resource utilization method for high-pressure acid leaching residues of laterite nickel ore. The method comprises: (1) performing alkaline washing and solid-liquid separation on high-pressure acid leaching residues of laterite nickel ore to obtain alkaline washed residues; (2) subjecting the alkaline washed residues in step (1) to first water washing and solid-liquid separation to obtain first water washed residues; (3) subjecting the first water washed residues in step (2) to acid washing and solid-liquid separation to obtain acid washed residues; and (4) subjecting the acid washed residues in step (3) to second water washing and solid-liquid separation to obtain second water washed residues, and drying same to obtain an iron concentrate product. The present application uses staged washing to selectively elute impurities from high-pressure acid leaching residues of laterite nickel ore, achieves iron enrichment and recovery, and obtains high-grade Hematite concentrate products, thereby achieving efficient resource utilization of high-pressure acid leaching residues of laterite nickel ore.

Description

Method for resource utilization of laterite nickel ore high-pressure acid leaching slag TECHNICAL FIELD

[0001] The present application relates to the technical field of resource recycling, and particularly relates to a method for resource utilization of laterite nickel ore high-pressure acid leaching slag. BACKGROUND

[0002] The laterite nickel ore high-pressure acid leaching slag contains a large amount of iron elements, and direct landfill will cause great waste of iron resources.

[0003] Related recycling methods are mostly through high-temperature roasting combined with magnetic separation to recover them in the form of magnetite concentrate. For example, CN117286334A discloses a method for high-value utilization of laterite nickel ore high-pressure acid leaching slag, which comprises the following steps: adding manganese iron slag and a composite additive to the laterite nickel ore high-pressure acid leaching slag for wet mixing, and then dehydrating and pressing into ball materials; the ball materials are subjected to drying, magnetization roasting, water quenching, grinding, and magnetic separation to obtain metal powder rich in iron elements and containing a small amount of manganese elements and tailing slurry; the metal powder is concentrated and dehydrated to obtain metal material; and the tailing slurry is concentrated and dehydrated to obtain cementitious material auxiliary. However, this method has a complex process, requires high-temperature roasting, has high energy consumption, and has a large environmental pressure of roasting flue gas.

[0004] CN113430390A discloses a treatment method of laterite nickel ore high-pressure acid leaching slag and a positive electrode material, which comprises placing the roasting material of the laterite nickel ore high-pressure acid leaching slag and an iron compound in an acid solution, performing acid leaching treatment, and performing solid-liquid separation to obtain leaching liquid and leaching residue; the leaching residue is subjected to roasting and leaching to obtain primary filtrate, and the primary filtrate is subjected to post-treatment to obtain iron phosphate; the leaching liquid is subjected to copper removal treatment, iron removal treatment, and calcium and magnesium removal treatment, and then nickel source, cobalt source, manganese source, and aluminum source are added to co-precipitate nickel-cobalt-manganese-aluminum hydroxide, but a large amount of iron resources are wasted in this method, and the resource utilization rate is low.

[0005] Therefore, the treatment method of the related art for treating the laterite nickel ore high-pressure acid leaching slag has the problems of low resource utilization rate and high energy consumption, and it is urgent to develop a new treatment method for the laterite nickel ore high-pressure acid leaching slag to improve the utilization rate of a large amount of iron resources in the laterite nickel ore high-pressure acid leaching slag.

[0006] SUMMARY

[0007] The following is a summary of the subject matter described in detail in this document. This summary is not intended to limit the scope of protection of the claims.

[0008] The application provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, which realizes efficient utilization of iron resources in the laterite nickel ore high-pressure acid leaching slag through the processes of alkali washing, first water washing, acid washing and second water washing in sequence without roasting, and significantly improves the resource utilization rate of the laterite nickel ore high-pressure acid leaching slag.

[0009] The application provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, which comprises the following steps:

[0010] (1) The laterite nickel ore high-pressure acid leaching slag is subjected to alkali washing and solid-liquid separation to obtain alkali washing slag.

[0011] (2) The alkali washing slag obtained in step (1) is subjected to first water washing and solid-liquid separation to obtain first water washing slag.

[0012] (3) The first water washing slag obtained in step (2) is subjected to acid washing and solid-liquid separation to obtain acid washing slag.

[0013] (4) The acid washing slag obtained in step (3) is subjected to second water washing and solid-liquid separation, and the second water washing slag obtained is dried to obtain an iron concentrate product.

[0014] The method for resource utilization of laterite nickel ore high-pressure acid leaching slag provided by the application can selectively wash out impurities in the laterite nickel ore high-pressure acid leaching slag through the steps of alkali washing, first water washing, acid washing and second water washing, realizes enrichment and recovery of iron, and obtains a high-grade iron concentrate product. Moreover, the method has mild reaction conditions, low energy consumption, is green and low-carbon, and has a wide application prospect.

[0015] Specifically, the impurity elements such as S, Al and Ca in the laterite nickel ore high-pressure acid leaching slag mainly exist in the form of composite sulfates, oxides and carbonates, are mixed together with iron elements, are wrapped together, and are difficult to remove. The alkali washing step can remove alkali-soluble impurities such as S, Al and Si. The purpose of the first water washing step is to wash residual alkali and residual alkali leaching liquid impurities in the slag. The purpose of the acid washing step is to remove acid-soluble impurities such as Ca, Al and Mg. The purpose of the second water washing step is to wash residual acid and residual acid leaching liquid impurities in the slag.

[0016] In one embodiment, the content of iron elements in the laterite nickel ore high-pressure acid leaching slag in step (1) is 35-45 wt%, for example, can be 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt% or 45 wt% and the like.

[0017] In one embodiment, the form of existence of iron element in the residue of high-pressure acid leaching of laterite nickel ore includes hematite phase; in one embodiment, the residue of high-pressure acid leaching of laterite nickel ore further contains S element, Al element, Ca element, Si element and Mg element; wherein the content of each element is: Al: 2.5-3.5wt%; Ca: 5-6wt%; S: 6-8wt%; Si: 0.1-0.2wt%; Mg: 0.3-0.5wt%.

[0018] In one embodiment, the form of existence of iron element in the residue of high-pressure acid leaching of laterite nickel ore includes hematite phase; in one embodiment, the residue of high-pressure acid leaching of laterite nickel ore further contains S element, Al element, Ca element, Si element and Mg element; wherein the content of each element is: Al: 2.5-3.5wt%; Ca: 5-6wt%; S: 6-8wt%; Si: 0.1-0.2wt%; Mg: 0.3-0.5wt%.

[0019] In one embodiment, the washing agent of the alkali washing in step (1) includes any one or a combination of at least two of sodium hydroxide solution, sodium carbonate solution, potassium hydroxide solution or potassium carbonate solution, wherein a typical but non-limiting combination is a combination of sodium hydroxide solution and sodium carbonate solution, a combination of potassium hydroxide solution and sodium carbonate solution, a combination of sodium hydroxide solution and potassium hydroxide solution, a combination of potassium carbonate solution and sodium carbonate solution.

[0020] In one embodiment, the concentration of the sodium hydroxide solution is 1.5-3 mol / L, for example, it can be 1.5 mol / L, 1.6 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L, 2.2 mol / L, 2.3 mol / L, 2.5 mol / L, or 3.0 mol / L, etc.

[0021] In one embodiment, the concentration of the potassium hydroxide solution is 1.5-3 mol / L, for example, it can be 1.5 mol / L, 1.6 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L, 2.2 mol / L, 2.3 mol / L, 2.5 mol / L, or 3.0 mol / L, etc.

[0022] In one embodiment, the concentration of the sodium carbonate solution is 0.5-2 mol / L, for example, it can be 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, or 2.0 mol / L, etc.

[0023] In one embodiment, the concentration of the potassium carbonate solution is 0.5-2 mol / L, for example, it can be 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, or 2.0 mol / L, etc.

[0024] The concentration of the detergent for the alkali washing in the present application can be selected within the above range, which can further improve the separation rate of iron and other impurity elements while ensuring the recovery rate of iron. When the alkali concentration is too low, there is a problem of insufficient removal of impurities S and Al. When the alkali concentration is too high, there is a problem of excess alkalinity and high cost.

[0025] In one embodiment, the liquid-solid mass ratio of the detergent for the alkali washing to the high-pressure acid leaching residue of laterite nickel ore in step (1) is (2-5):1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.5:1, 2.8:1, 3.0:1, 3.2:1, 3.3:1, 3.5:1, 4.0:1, 4.5:1, or 5.0:1, etc.

[0026] In one embodiment, the temperature of the alkali washing is 20-90℃, for example, it can be 20℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 80℃, 85℃, or 90℃, etc.

[0027] In one embodiment, the time of the alkaline washing is 1-4h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, etc.

[0028] In one embodiment, the liquid-solid mass ratio of the first water washing in step (2) is (2-5):1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.5:1, 2.8:1, 3.0:1, 3.2:1, 3.3:1, 3.5:1, 4.0:1, 4.5:1 or 5.0:1, etc.

[0029] In one embodiment, the washing mode of the first water washing includes single-stage washing or multi-stage countercurrent washing.

[0030] In one embodiment, the washing agent of the acid washing in step (3) includes hydrochloric acid and / or nitric acid.

[0031] In one embodiment, the pH of the acid washing is 1.0-3.0, for example, it can be 1.0, 1.2, 1.3, 1.5, 1.8, 2.0, 2.2, 2.3, 2.5, 2.8 or 3.0, etc.

[0032] The pH of the acid washing in the present application can be selected as 1.0-3.0, which can improve the separation rate of iron and other impurity elements while ensuring the recovery rate of iron. When the pH is too low, there is a problem of too much iron loss, and when the pH is too high, there is a problem of insufficient elution of Ca and Al impurities.

[0033] In one embodiment, the temperature of the acid washing in step (3) is 20-90℃, for example, it can be 20℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 70℃, 80℃ or 90℃, etc.

[0034] In one embodiment, the time of the acid washing is 1-4h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, etc.

[0035] In one embodiment, the liquid-solid mass ratio of the acid washing is (2-5):1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.5:1, 2.8:1, 3.0:1, 3.2:1, 3.3:1, 3.5:1, 4.0:1, 4.5:1 or 5.0:1, etc.

[0036] In one embodiment, the liquid-solid mass ratio of the second water washing in step (4) is (2-5):1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.5:1, 2.8:1, 3.0:1, 3.2:1, 3.3:1, 3.5:1, 4.0:1, 4.5:1 or 5.0:1, etc.

[0037] In one embodiment, the washing mode of the second water washing comprises single-stage washing or multi-stage countercurrent washing.

[0038] In one embodiment, the temperature of the drying in step (4) is 100-150℃, for example, it can be 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃, etc.

[0039] Since the drying time varies greatly due to different drying equipment in industrial production, the drying time is not limited here, and drying is sufficient. As an optional technical solution of the present application, the method comprises the following steps:

[0040] (1) The laterite nickel ore high-pressure acid leaching residue is alkali washed at a liquid-solid mass ratio of (2-5):1 and a temperature of 20-90℃ for 1-4h, and then solid-liquid separation is performed to obtain an alkali washed residue;

[0041] The washing agent for the alkali washing comprises any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution, a potassium hydroxide solution or a potassium carbonate solution;

[0042] (2) The alkali washed residue in step (1) is subjected to first water washing at a liquid-solid mass ratio of (2-5):1 and solid-liquid separation to obtain a first water washed residue;

[0043] (3) The first water washed residue in step (2) is acid washed at a pH of 1.0-3.0, a liquid-solid mass ratio of (2-5):1 and a temperature of 20-90℃ for 1-4h, and then solid-liquid separation is performed to obtain an acid washed residue;

[0044] The washing agent for the acid washing comprises hydrochloric acid and / or nitric acid;

[0045] (4) The acid washed residue in step (3) is subjected to second water washing at a liquid-solid mass ratio of (2-5):1 and solid-liquid separation, and the obtained second water washed residue is dried at 100-150℃ to obtain an iron concentrate product.

[0046] In step (2), the first water washing liquid after the first water washing is recycled to step (1) as a washing agent for the alkali washing; in step (4), the second water washing liquid after the second water washing is recycled to step (3) as a washing agent for the acid washing.

[0047] The solid-liquid separation in the above process is not specially limited in the present application, and any device and mode known to those skilled in the art that can be used for solid-liquid separation can be used, and it can also be adjusted according to the actual process, for example, it can be filtration, centrifugation or sedimentation separation, etc., or a combination of different modes.

[0048] The drying in the above process is not particularly limited in the present application, any device and mode for drying known to those skilled in the art can be used, and adjustment can be made according to the actual process, for example, air drying, vacuum drying, drying or freeze drying, etc., or a combination of different modes.

[0049] Compared with the related art, the present application has at least the following beneficial effects:

[0050] (1) The method for resource utilization of laterite nickel ore high-pressure acid leaching slag provided by the present application can selectively elute the impurities in the laterite nickel ore high-pressure acid leaching slag through staged washing, realizing the enrichment and recovery of iron, and the recovery rate of iron can be as high as 98% or more.

[0051] (2) The method for resource utilization of laterite nickel ore high-pressure acid leaching slag provided by the present application sequentially uses the processes of alkali washing, first water washing, acid washing and second water washing, and high-grade hematite concentrate products can be obtained without roasting, wherein the iron content in the hematite concentrate products can be as high as 63wt% or more, realizing efficient resource utilization of laterite nickel ore high-pressure acid leaching slag, and the reaction conditions are mild, the energy consumption is low, it is green and low-carbon, and has a wide application prospect.

[0052] Other aspects can be appreciated upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings are included to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical solutions of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0054] FIG. 1 is a flowchart of the method for resource utilization of laterite nickel ore high-pressure acid leaching slag provided by the present application. DETAILED DESCRIPTION

[0055] In order to facilitate the understanding of the present application, the present application is listed as follows. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as a specific limitation on the present application.

[0056] It should be understood that, in the description of the present application, the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second", etc. can be explicitly or implicitly included one or more features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0057] As a specific embodiment of the present application, a method for resource utilization of laterite nickel ore high-pressure acid leaching slag is provided, as shown in FIG. 1, the method comprises the following steps:

[0058] (1) the limonite nickel ore high-pressure acid leaching slag is alkali washed for 1-4 h under the conditions of a liquid-solid mass ratio of (2-5): 1 and a temperature of 20-90℃, and solid-liquid separation is performed, to obtain alkali washed slag;

[0059] The washing agent for the alkali washing includes any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution, a potassium hydroxide solution or a potassium carbonate solution.

[0060] (2) the alkali washed slag in step (1) is first water washed at a liquid-solid mass ratio of (2-5): 1, and solid-liquid separation is performed, to obtain first water washed slag;

[0061] (3) the first water washed slag in step (2) is acid washed for 1-4 h under the conditions of a pH of 1.0-3.0, a liquid-solid mass ratio of (2-5): 1 and a temperature of 20-90℃, and solid-liquid separation is performed, to obtain acid washed slag;

[0062] The washing agent for the acid washing includes hydrochloric acid and / or nitric acid.

[0063] (4) the acid washed slag in step (3) is second water washed at a liquid-solid mass ratio of (2-5): 1, and solid-liquid separation is performed, and the second water washed slag obtained is dried at 100-150℃, to obtain an iron concentrate product.

[0064] The first water washing liquid after the first water washing in step (2) is recycled to step (1) to be used as a washing agent for preparing the liquid bottom water for the alkali washing; and the second water washing liquid after the second water washing in step (4) is recycled to step (3) to be used as a washing agent for preparing the liquid bottom water for the acid washing.

[0065] For the convenience of experiments, the limonite nickel ore high-pressure acid leaching slag used in the examples and comparative examples has the following specific composition: Fe: 35-45wt%; Al: 2.5-3.5wt%; Ca: 5-6wt%; S: 6-8wt%; Si: 0.1-0.2wt%; and Mg: 0.3-0.5wt%. However, it does not mean that the method for resource utilization of the limonite nickel ore high-pressure acid leaching slag provided in the present application must be performed using the above limonite nickel ore high-pressure acid leaching slag, and other compositions known to those skilled in the art can also be used.

[0066] Example 1

[0067] The present example provides a method for resource utilization of limonite nickel ore high-pressure acid leaching slag, as shown in FIG. 1, which comprises the following steps:

[0068] (1) The laterite nickel ore high-pressure acid leaching slag (specific group includes Fe: 40wt%; Al: 3.0wt%; Ca: 5.5wt%; S: 6.5wt%; Si: 0.15wt%; Mg: 0.4wt%) is alkali washed for 3h under the conditions of liquid-solid mass ratio of 3:1 and temperature of 70℃, the washing agent of alkali washing is sodium hydroxide solution with a concentration of 2.0mol / L, and centrifugal separation is performed to obtain alkali washed slag;

[0069] (2) The alkali washed slag in step (1) is first water washed with liquid-solid mass ratio of 3:1, the washing mode of the first water washing is single-stage washing, and centrifugal separation is performed to obtain first water washed slag;

[0070] (3) The first water washed slag in step (2) is acid washed with hydrochloric acid for 3h under the conditions of pH of 2.5, liquid-solid mass ratio of 2.5:1 and temperature of 70℃, and centrifugal separation is performed to obtain acid washed slag;

[0071] (4) The acid washed slag in step (3) is second water washed with liquid-solid mass ratio of 2.5:1, the washing mode of the second water washing is single-stage washing, and centrifugal separation is performed, and the obtained second water washed slag is dried at 120℃ to obtain iron concentrate product.

[0072] Example 2

[0073] The embodiment provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, and the method comprises the following steps:

[0074] (1) The laterite nickel ore high-pressure acid leaching slag (specific group includes Fe: 35wt%; Al: 2.5wt%; Ca: 5.0wt%; S: 6.0wt%; Si: 0.1wt%; Mg: 0.3wt%) is alkali washed for 1h under the conditions of liquid-solid mass ratio of 2:1 and temperature of 90℃, the washing agent of alkali washing is potassium hydroxide solution with a concentration of 1.5mol / L, and filtration separation is performed to obtain alkali washed slag;

[0075] (2) The alkali washed slag in step (1) is first water washed with liquid-solid mass ratio of 2:1, the washing mode of the first water washing is 4-stage countercurrent washing, and centrifugal separation is performed to obtain first water washed slag;

[0076] (3) The first water washed slag in step (2) is acid washed with nitric acid for 4h under the conditions of pH of 3.0, liquid-solid mass ratio of 2.0:1 and temperature of 20℃, and centrifugal separation is performed to obtain acid washed slag;

[0077] (4) The acid washed slag in step (3) is second water washed with liquid-solid mass ratio of 2:1, the washing mode of the second water washing is 5-stage countercurrent washing, and filtration separation is performed, and the obtained second water washed slag is dried at 150℃ to obtain iron concentrate product.

[0078] Example 3

[0079] The embodiment provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, and the method comprises the following steps:

[0080] (1) The laterite nickel ore high-pressure acid leaching slag (specific components include Fe: 45wt%, Al: 3.5wt%, Ca: 6wt%, S: 8wt%, Si: 0.2wt%, and Mg: 0.5wt%) is alkali washed for 4h under the condition that the liquid-solid mass ratio is 5:1 and the temperature is 20 DEG C, the alkali washing detergent is a sodium carbonate solution with a concentration of 0.5mol / L, and filtration separation is carried out, so that the alkali washing residue is obtained;

[0081] (2) The alkali washing residue in step (1) is first washed with water under the condition that the liquid-solid mass ratio is 5:1, the first water washing is single-stage washing, and centrifugal separation is carried out, so that the first water washing residue is obtained;

[0082] (3) The first water washing residue in step (2) is hydrochloric acid washed under the condition that the pH is 1.0, the liquid-solid mass ratio is 5.0:1, the temperature is 90 DEG C, and centrifugal separation is carried out, so that the acid washing residue is obtained;

[0083] (4) The acid washing residue in step (3) is second washed with water under the condition that the liquid-solid mass ratio is 5:1, the first water washing is two-stage countercurrent washing, and filtration separation is carried out, so that the second water washing residue is obtained, and the second water washing residue is dried at 100 DEG C, so that the iron concentrate product is obtained.

[0084] Embodiment 4

[0085] The embodiment provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, and the method comprises the following steps:

[0086] (1) The laterite nickel ore high-pressure acid leaching slag is alkali washed for 2.5h under the condition that the liquid-solid mass ratio is 2.5:1 and the temperature is 30 DEG C, the alkali washing detergent is a potassium carbonate solution with a concentration of 1.5mol / L, and centrifugal separation is carried out, so that the alkali washing residue is obtained;

[0087] (2) The alkali washing residue in step (1) is first washed with water under the condition that the liquid-solid mass ratio is 2.5:1, the first water washing is two-stage countercurrent washing, and filtration separation is carried out, so that the first water washing residue is obtained;

[0088] (3) The first water washing residue in step (2) is hydrochloric acid washed under the condition that the pH is 3.0, the liquid-solid mass ratio is 4.50:1, the temperature is 70 DEG C, and centrifugal separation is carried out, so that the acid washing residue is obtained;

[0089] (4) The acid washing residue in step (3) is second washed with water under the condition that the liquid-solid mass ratio is 3.5:1, the first water washing is single-stage washing, and filtration separation is carried out, so that the second water washing residue is obtained, and the second water washing residue is dried at 120 DEG C, so that the iron concentrate product is obtained.

[0090] Example 5

[0091] The present example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the concentration of sodium hydroxide solution in step (1) is 3.5 mol / L, which is not repeated here.

[0092] Example 6

[0093] The present example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the concentration of sodium hydroxide solution in step (1) is 1.0 mol / L, which is not repeated here.

[0094] Example 7

[0095] The present example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the pH in step (3) is 0.5, which is not repeated here.

[0096] Example 8

[0097] The present example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the pH in step (3) is 3.5, which is not repeated here.

[0098] Comparative Example 1

[0099] The present comparative example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the alkali washing in step (1) is not performed, which is not repeated here.

[0100] Comparative Example 2

[0101] The present comparative example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the first water washing in step (2) is not performed, which is not repeated here.

[0102] Comparative Example 3

[0103] The present comparative example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the acid washing in step (3) is not performed, which is not repeated here.

[0104] Comparative Example 4

[0105] The present comparative example provides a method for resource utilization of high-pressure acid leaching residue of laterite nickel ore, which is the same as example 1 except that the second water washing in step (4) is not performed, which is not repeated here.

[0106] Comparative Example 5

[0107] The present comparative example provides a method for resource utilization of laterite nickel ore high-pressure acid leaching slag, which is the same as example 1 except that the order of alkali washing and acid washing in step (1) and step (3) is reversed, and details are not repeated here.

[0108] Test method: GB / T 36704-2018 iron concentrate national standard method is used to test the iron content and other impurity element content in the iron concentrate product, and the iron recovery rate is calculated.

[0109] The test results of the above examples and comparative examples are shown in Table 1.

[0110] Table 1

[0111] From Table 1, it can be seen that:

[0112] (1) From examples 1-4, it can be seen that the method for resource utilization of laterite nickel ore high-pressure acid leaching slag provided by the present application can selectively wash out the impurities in the laterite nickel ore high-pressure acid leaching slag, realize the enrichment and recovery of iron, and obtain high-grade hematite concentrate product, wherein the iron content in the hematite concentrate product is more than 63wt%, and the yield is more than 98%; wherein the content of S impurity element is reduced to less than 0.1wt%, the content of Al impurity element is reduced to less than 0.35wt%, and the content of Ca impurity element is reduced to less than 0.15wt%;

[0113] (2) From examples 1 and 5-6, it can be seen that in example 1, sodium hydroxide solution with a concentration of 2.0mol / L is used as the detergent for alkali washing, compared with 3.5mol / L and 1.0mol / L in examples 5-6, the iron content in the hematite concentrate product in example 1 is 65.6wt%, and the iron yield is 99.2%, while the product purity of example 5 is similar to that of example 1, but the excessive amount of alkali will lead to relatively high cost; compared with example 1, the iron purity of the iron concentrate product in example 6 is reduced to 61.8%, and the impurity content is also high, which shows that the concentration of sodium hydroxide or potassium hydroxide in the detergent for alkali washing can be controlled within a certain range, which can further improve the iron content and iron recovery rate of the hematite concentrate product while controlling the cost; adjusting the concentration of sodium carbonate solution or potassium carbonate solution can also find that controlling the concentration of carbonate solution within a certain range can also improve the iron content and iron recovery rate of the hematite concentrate product, and details are not repeated here;

[0114] (3) From the combination of Example 1 and Examples 7-8, it can be seen that, compared with the pH of 0.5 and the pH of 3.5 in Examples 7-8, the iron content in the hematite concentrate product in Example 1 is 65.6wt%, and the iron yield is more than 99.2%, while the iron yield in Example 7 is reduced to 96.2%, and the iron purity in the hematite concentrate product in Example 8 is reduced to 60.6%. Thus, it is shown that the pH of the pickling can be controlled in a specific range, which can promote the removal of impurities while ensuring the iron recovery, and further improve the iron content in the hematite concentrate product;

[0115] (4) From the combination of Example 1 and Comparative Examples 1-5, it can be seen that the method for resource utilization of high-pressure acid leaching residue of laterite nickel ore provided by the present application can selectively wash out the impurities in the high-pressure acid leaching residue of laterite nickel ore by strictly adopting the step process of alkali washing, first water washing, pickling and second water washing, so as to realize the enrichment and recovery of iron, and obtain a high-grade hematite concentrate product. When the above steps or sequence are not adopted in Comparative Examples 1-5, the impurities are significantly higher, the product purity is seriously insufficient, and it is difficult to realize the efficient resource utilization of the high-pressure acid leaching residue of laterite nickel ore.

[0116] The above examples are used to illustrate the detailed features of the present application, but the present application is not limited to the above detailed features, i.e. it does not mean that the present application must rely on the above detailed features to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of the technical features selected by the present application, addition of auxiliary technical features, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for resource utilization of laterite nickel ore high-pressure acid leaching residue, comprising: (1) alkali washing and solid-liquid separation of the laterite nickel ore high-pressure acid leaching residue to obtain an alkali washed residue; (2) first water washing and solid-liquid separation of the alkali washed residue of step (1) to obtain a first water washed residue; (3) acid washing and solid-liquid separation of the first water washed residue of step (2) to obtain an acid washed residue; (4) second water washing and solid-liquid separation of the acid washed residue of step (3) to obtain a second water washed residue, and drying the second water washed residue to obtain an iron concentrate product.

2. The method of claim 1, wherein, The iron content in the laterite nickel ore high-pressure acid leaching residue in step (1) is 35-45 wt%; Optionally, the iron in the laterite nickel ore high-pressure acid leaching residue exists in the form of hematite phase; optionally, the laterite nickel ore high-pressure acid leaching residue further contains S, Al, Ca, Si and Mg elements; wherein the content of each element is: Al: 2.5-3.5 wt%; Ca: 5-6 wt%; S: 6-8 wt%; Si: 0.1-0.2 wt%; Mg: 0.3-0.5 wt%.

3. The method of claim 1 or 2, wherein, The washing agent for the alkali washing in step (1) comprises any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution, a potassium hydroxide solution or a potassium carbonate solution; Optionally, the concentration of the sodium hydroxide solution is 1.5-3 mol / L; Optionally, the concentration of the potassium hydroxide solution is 1.5-3 mol / L; Optionally, the concentration of the sodium carbonate solution is 0.5-2 mol / L; Optionally, the concentration of the potassium carbonate solution is 0.5-2 mol / L.

4. The method according to any one of claims 1 to 3, wherein, The liquid-solid mass ratio of the washing agent for the alkali washing in step (1) to the laterite nickel ore high-pressure acid leaching residue is (2-5): 1; Optionally, the temperature of the alkali washing is 20-90℃; Optionally, the time of the alkali washing is 1-4 h.

5. The method according to any one of claims 1 to 4, wherein, The liquid-solid mass ratio of the first water washing in step (2) is (2-5): 1; Optionally, the washing mode of the first water washing comprises single-stage washing or multi-stage countercurrent washing.

6. The method according to any one of claims 1 to 5, wherein, The washing agent for the acid washing in step (3) comprises hydrochloric acid and / or nitric acid; Optionally, the pH of the acid washing is 1.0-3.

0.

7. The method according to any one of claims 1 to 6, wherein, The temperature of the acid washing in step (3) is 20-90℃; Optionally, the time of the acid washing is 1-4 h; Optionally, the liquid-solid mass ratio of the acid washing is (2-5):

1.

8. The method according to any one of claims 1 to 7, wherein, The liquid-solid mass ratio of the second water washing in step (4) is (2-5): 1; Optionally, the washing mode of the second water washing comprises single-stage washing or multi-stage countercurrent washing.

9. The method according to any one of claims 1 to 8, wherein, The temperature of the drying in step (4) is 100-150℃. 10.The method according to any one of claims 1-9, comprising the following steps: (1) alkali washing of the laterite nickel ore high-pressure acid leaching residue at a liquid-solid mass ratio of (2-5): 1 and a temperature of 20-90℃ for 1-4 h, and solid-liquid separation to obtain an alkali washed residue; wherein The washing agent for the alkali washing comprises any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution, a potassium hydroxide solution or a potassium carbonate solution; (2) first water washing and solid-liquid separation of the alkali washed residue of step (1) at a liquid-solid mass ratio of (2-5): 1 to obtain a first water washed residue; (3) the first water washing residue in step (2) is pickled at a pH of 1.0-3.0, a liquid-solid mass ratio of (2-5):1, and a temperature of 20-90℃ for 1-4h, and then solid-liquid separation is performed to obtain a pickling residue; wherein the pickling detergent comprises hydrochloric acid and / or nitric acid; (4) the pickling residue in step (3) is subjected to second water washing at a liquid-solid mass ratio of (2-5):1 and solid-liquid separation, and the obtained second water washing residue is dried at 100-150℃ to obtain an iron concentrate product. ​

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