Oxygen pressure acid leaching solution extraction process

Abstract

The invention discloses an oxygen pressure acid leaching solution extraction process, which relates to the technical field of nickel extraction, and comprises the following steps: carrying out primary pH value adjustment and solid-liquid separation on a leaching solution output by a high-pressure reaction kettle in advance to obtain a solution A; the solution A is subjected to an N235 extraction procedure, reverse extraction raffinate A and extraction liquid A are obtained, and the content of vanadium in the extraction liquid A is smaller than 0.5 g / L; carrying out secondary pH value adjustment and solid-liquid separation on the extract A to obtain a solution B; and the solution B is subjected to an HBL110 extraction procedure, reverse extraction raffinate B and extraction liquid B are obtained and used for separating nickel metal and aluminum metal, other impurities in the solution B are removed, and the nickel content in the extraction liquid B is smaller than or equal to 0.1 g / L. According to the method, the leaching rate is high, under the action of high temperature, high pressure and oxygen, the nickel mineral fully reacts with the acid, the leaching rate of nickel can be remarkably increased and can reach 95% or above, and valuable metal such as nickel can be effectively extracted from the ore.

Description

Technical Field

[0001] The invention relates to the technical field of nickel extraction, in particular to an oxygen pressure acid leaching solution extraction process. Background Art

[0002] Oxygen pressure acid leaching uses oxygen as an oxidant under high temperature, high pressure and acidic conditions to make the valuable metals in the ore or concentrate react with acid and convert them into soluble metal ions that enter the solution, while impurities are separated in the form of precipitation or other forms. For example, in the oxygen pressure acid leaching of zinc concentrate, zinc sulfide reacts with sulfuric acid to produce zinc sulfate and hydrogen sulfide, and hydrogen sulfide reacts with oxygen to produce elemental sulfur and water. The extraction principle uses the different solubility of solutes in immiscible solvents to extract the solutes from the solution composed of another solvent with one solvent. In the oxygen pressure acid leaching extraction process, organic extractants are usually used to selectively transfer the valuable metal ions in the leachate to the organic phase, while the impurities remain in the aqueous phase, thereby achieving the separation of valuable metals and impurities.

[0003] At present, the conventional oxygen pressure acid leaching process has problems such as low leaching rate and high impurity content when extracting nickel. In the process of leaching nickel, other impurity metals are also easily leached at the same time. For example, metals such as iron and cobalt in the ore will also react with acid and enter the solution under oxygen pressure acid leaching conditions. This increases the difficulty of subsequent extraction and separation, and requires the use of complex extractants and extraction processes to achieve the separation of nickel from other metals. Moreover, the presence of impurity metals may affect the performance and service life of the extractant, increasing the extraction cost.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In view of the problems in the related art, the present invention proposes an oxygen pressure acid leaching solution extraction process to overcome the above technical problems existing in the existing related technology.

[0006] The technical solution of the present invention is achieved in this way:

[0007] An oxygen pressure acid leaching solution extraction process comprises the following steps:

[0008] The pH value of the leaching solution output from the high-pressure reactor is adjusted and the solid-liquid separation is performed in advance to obtain solution A;

[0009] The solution A is subjected to a N235 extraction process to obtain a stripping raffinate A and an extract A, wherein the vanadium content in the extract A is less than 0.5 g / L;

[0010] The extract A is subjected to a second adjustment of pH value and solid-liquid separation to obtain solution B;

[0011] Solution B is subjected to the HBL110 extraction process to obtain stripping solution B and extract solution B for separating nickel metal and aluminum metal, and removing other impurities in solution B, and the nickel content in extract solution B is ≤0.1 g / L.

[0012] The one-time adjustment of pH value includes: adding flake caustic soda or soda ash to adjust the pH value, and the pH value after the addition is controlled to be 1.5-2.5.

[0013] The N235 extraction process includes: using a centrifugal extractor or an extraction tank, wherein the extraction process is: acidification, 2-stage extraction, 1-stage clarification and 1-2-stage stripping.

[0014] Wherein, the secondary adjustment of pH value comprises: adding soda ash or flake caustic soda solution, and performing secondary pH adjustment of extract A to adjust the pH value to 1.5-2.5.

[0015] Wherein, the solution B is subjected to the HBL110 extraction process, including: using a centrifugal extractor or an extraction tank, wherein the extraction process is: 3-stage saponification, 5-stage extraction, 2-stage washing, 2-stage stripping and 2-stage backwashing.

[0016] Beneficial effects of the present invention:

[0017] 1. The present invention has a high leaching rate. Under the action of high temperature, high pressure and oxygen, the nickel ore fully reacts with the acid, which can significantly increase the leaching rate of nickel to more than 95%, and effectively extract nickel and other valuable metals from the ore.

[0018] 2. The present invention has good selectivity. By optimizing and controlling the extractant and extraction conditions, the selective separation of nickel and other impurity metals can be achieved, thereby improving the purity of the nickel product. At the same time, in industrial applications, for some low-grade nickel ores, traditional processes may be difficult to economically and effectively extract the valuable metals therein, while the present invention has good adaptability and can achieve the recovery and utilization of valuable metals in low-grade ores, thereby broadening the source of nickel resources.

[0019] 3. The present invention generates relatively less waste gas, waste water and waste residue, which causes less pollution to the environment and meets the development requirements of modern green metallurgy. At the same time, nickel and cobalt can be extracted efficiently, and other valuable metals in the ore, such as copper, zinc, gold, silver, etc., can be recovered at the same time, thereby improving the comprehensive utilization efficiency of resources and increasing economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 The figure is a schematic flow chart of an oxygen pressure acid leaching solution extraction process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 belong to the scope of protection of the present invention.

[0023] According to an embodiment of the present invention, an oxygen pressure acid leaching solution extraction process is provided.

[0024] like Figure 1 As shown, the oxygen pressure acid leaching solution extraction process according to an embodiment of the present invention includes the following steps:

[0025] Step S1, adjusting the pH value and performing solid-liquid separation on the leaching solution output from the high-pressure reactor in advance to obtain solution A;

[0026] The pH value is adjusted once, stirring is turned on during the process, and flake caustic soda or soda ash is added to adjust the pH value. At the same time, the pH value after addition is controlled to be 1.5-2.5. After stirring evenly, sampling is performed, and the nickel content and vanadium content in the slurry are measured to facilitate the subsequent N253 extraction operation.

[0027] The slurry after adjusting the pH value is directly pumped to the plate-frame or diaphragm filter press for solid-liquid separation. The slag after solid-liquid separation enters the vanadium-molybdenum treatment section; and solution A is finely filtered and pumped to the N235 extraction stock tank for extraction treatment.

[0028] In this technical solution, the pH value of the leaching solution from the high-pressure reactor is adjusted and the solid-liquid separation is performed. On the one hand, the solid in the slurry is removed by solid-liquid separation, and on the other hand, the extraction requirements of the N235 extraction process can be met.

[0029] Step S2, subjecting solution A to a N235 extraction process to obtain a stripping raffinate A and an extract A, wherein the vanadium content in the extract A is less than 0.5 g / L;

[0030] The technical solution includes: using a centrifugal extractor or an extraction tank, wherein the extraction process is: acidification, 1 to 3 levels: 2 levels of extraction, 1 level of clarification, and 1 to 2 levels of stripping.

[0031] Specifically, when applying, the relevant parameters are as follows:

[0032] Acidification and extraction: The volume ratio of the organic phase is 70% solvent oil + 20% N235 + 10% isooctyl alcohol, and the weight ratio is 0.8:0.8:0.8; the acidity of the extraction solution is pH = 1.5-2.5; the flow ratio 0 / A1: 1.5-2.5; the contact time is 5-8 min; the stratification time is 10 min; the number of stages is 2; the temperature is 20-45 ° C.

[0033] Stripping: Regeneration agent: 4N liquid alkali; Contact phase ratio: 1:1~2 / 1; Temperature: 20-45℃; Contact time: 5~8min; Number of stages: 1~2 levels; Layering time: 10min.

[0034] With the help of the above scheme, the stripping raffinate A after N235 extraction mainly contains vanadium and molybdenum, and the stripping raffinate A is directly pumped to the vanadium and molybdenum treatment section for treatment. The extract A mainly contains nickel and aluminum, as well as other impurities, which are pumped to the impurity removal tank for secondary pH adjustment before HBL110 extraction.

[0035] Step S3, adjusting the pH value of the extract A for a second time and performing solid-liquid separation to obtain solution B;

[0036] In this technical solution, the extract A after N235 extraction is adjusted for a second time by adding soda ash / flaked caustic soda solution to adjust the pH value to 1.5-2.5, and after being fully stirred, it is pumped to the plate and frame filter press for solid-liquid separation. The solution B after solid-liquid separation is pumped to the HBL110 stock liquid tank for extraction treatment. The produced slag is treated by pyrometallurgy or external treatment.

[0037] Step S4, subjecting solution B to an HBL110 extraction process to obtain stripping solution B and extract solution B for separating nickel metal and aluminum metal, and removing other impurities in solution B, and the nickel content in extract solution B is ≤0.1 g / L.

[0038] In the present technical solution, HBL110 extraction can use a centrifugal extractor or an extraction tank, specifically 3 stages of saponification, 5 stages of extraction, 2 stages of washing, 2 stages of stripping, and 2 stages of backwashing.

[0039] Specifically, when applying, the relevant parameters are as follows:

[0040] Saponification extraction conditions: organic phase: 45% extractant + 55% kerosene, which can be adjusted according to the specific situation; Ni element concentration in the feed liquid ≤ 15g / L; feed liquid temperature: 25℃~40℃; saponification before extraction: 5~10mol / LNaOH solution saponification, saponification rate is 40%~50% according to the acidity value of the organic phase before and after saponification. Extraction time: t: 3~10min; pH value of raw material liquid: 1.5~2.5; extraction ratio: calculated according to the nickel metal concentration of the stock solution and the metal migration amount of the extractant, the specific operation can be appropriately adjusted according to the actual situation. Number of stages: 3-stage saponification, 5-stage extraction.

[0041] Washing conditions: washing time: 3 to 10 minutes; washing temperature: 25°C; washing agent concentration: 5 to 10 g / L sulfuric acid solution; washing level: 1 to 2 levels, the washing level can be increased according to actual conditions.

[0042] Stripping conditions: Stripping time: 3-10 min; Stripping temperature: 25°C; Stripping agent concentration: 50-100 g / L sulfuric acid solution; Level: 2 or above, the stripping level can be increased according to actual conditions;

[0043] Backwash conditions: backwash time: 3 to 10 minutes; backwash temperature: 25°C; backwash agent concentration: pure water or soft water; level: 1 to 3 levels of backwashing, the backwash level can be increased according to actual conditions.

[0044] Raffinate: Ni≤0.1g / L.

[0045] Stripping raffinate: Ni ≥ 25g / L.

[0046] With the help of the above scheme, the stripping raffinate B after HBL110 extraction is a nickel sulfate solution, and its purity can meet the needs of take-out or electrolytic pre-liquid. During the HBL110 extraction process, parameter control is performed, and the stripping solution B can be directly enriched with nickel precipitation and then enter electrolysis or electrolytic deposition.

[0047] In addition, the present invention was experimentally studied with conventional oxygen pressure acid leaching solution extraction process, reduction roasting-normal pressure ammonia leaching method, chemical precipitation method, ionic liquid method and electrochemical method, as shown in Table 1:

[0048]

[0049] Table 1 Experimental control analysis table

[0050] With the help of Table 1 above, the nickel leaching efficiency of the present invention is high, nickel can be fully leached into the solution, the nickel leaching rate can usually reach more than 95%, and the leaching rate in industrial applications is high and stable. In addition, by controlling the leaching conditions and the selection of the extractant, the separation of nickel and other impurities can be better achieved. At the same time, by selecting the extractant and optimizing the extraction conditions, the selective separation of nickel and cobalt can be achieved. Especially when treating low-grade ores or complex ores, it has good economic benefits, and the amount of waste gas, wastewater and waste residue generated is relatively small.

[0051] In summary, with the help of the above technical solution of the present invention, the following effects can be achieved:

[0052] 1. The present invention has a high leaching rate. Under the action of high temperature, high pressure and oxygen, the nickel ore fully reacts with the acid, which can significantly increase the leaching rate of nickel to more than 95%, and effectively extract nickel and other valuable metals from the ore.

[0053] 2. The present invention has good selectivity. By optimizing and controlling the extractant and extraction conditions, the selective separation of nickel and other impurity metals can be achieved, thereby improving the purity of the nickel product. At the same time, in industrial applications, for some low-grade nickel ores, traditional processes may be difficult to economically and effectively extract the valuable metals therein, while the present invention has good adaptability and can achieve the recovery and utilization of valuable metals in low-grade ores, thereby broadening the source of nickel resources.

[0054] 3. The present invention generates relatively less waste gas, waste water and waste residue, which causes less pollution to the environment and meets the development requirements of modern green metallurgy. At the same time, nickel and cobalt can be extracted efficiently, and other valuable metals in the ore, such as copper, zinc, gold, silver, etc., can be recovered at the same time, thereby improving the comprehensive utilization efficiency of resources and increasing economic benefits.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. After considering the disclosure of the specification and the examples, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptive change of the present disclosure, which follows the principle of the present disclosure and includes common knowledge or customary technical means in the technical field that are not disclosed in the present disclosure. The specification and the examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0056] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An oxygen pressure acid leaching solution extraction process, characterized in that: The following steps are involved: The pH value of the leaching solution output from the high-pressure reactor is adjusted and the solid-liquid separation is performed in advance to obtain solution A; The solution A is subjected to a N235 extraction process to obtain a stripping raffinate A and an extract A, wherein the vanadium content in the extract A is less than 0.5 g / L; The extract A is subjected to a second adjustment of pH value and solid-liquid separation to obtain solution B; Solution B is subjected to the HBL110 extraction process to obtain stripping solution B and extract solution B for separating nickel metal and aluminum metal, and removing other impurities in solution B, and the nickel content in extract solution B is ≤0.1 g / L.

2. The oxygen pressure acid leaching solution extraction process according to claim 1, characterized in that: The one-time adjustment of pH value includes: adding flake caustic soda or soda ash to adjust the pH value, and the pH value after the addition is controlled to be 1.5-2.

5.

3. The oxygen pressure acid leaching solution extraction process according to claim 1, characterized in that: The N235 extraction process includes: using a centrifugal extractor or an extraction tank, wherein the extraction process is: acidification, 2-stage extraction, 1-stage clarification and 1-2-stage stripping.

4. The oxygen pressure acid leaching solution extraction process according to claim 1, characterized in that: The second adjustment of pH value includes: adding soda ash or flake caustic soda solution, and performing a second pH adjustment on the extract A to adjust the pH value to 1.5-2.

5.

5. The oxygen pressure acid leaching solution extraction process according to claim 1, characterized in that: The solution B is subjected to the HBL110 extraction process, including: using a centrifugal extractor or an extraction tank, wherein the extraction process is: 3-stage saponification, 5-stage extraction, 2-stage washing, 2-stage stripping and 2-stage backwashing.

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