CN104480307A - Mixed extraction agent for separating iron, aluminium and nickel-cobalt-magnesium from nickel oxide oresulfuric acid leaching solution as well as separation method - Google Patents

Abstract

The invention discloses a mixed extraction agent and a separation method for separating iron, aluminum and nickel-cobalt-magnesium in sulfuric acid leaching solution of nickel oxide ore. The mixed extractant is composed of 10-50% of P204, 10-40% of amine extractant and the rest of solvent in volume percentage. The method selects P204, amine extractant and solvent to form a mixed extractant, selects water and dilute sulfuric acid as detergent and stripping agent, extracts and separates the sulfuric acid leachate of nickel oxide ore, and undergoes the steps of extraction, washing and stripping, Sulfuric acid solution, aluminum sulfate solution and iron sulfate solution containing nickel, cobalt and magnesium are respectively obtained at the outlet of the extraction section, the outlet of the washing section and the outlet of the stripping section, and the mixed solution of nickel, cobalt and magnesium can be further separated through the subsequent extraction process. The mixed extractant system used in the present invention has strong separation ability for iron and aluminum and iron-aluminum, nickel-cobalt-magnesium, the extractant does not need saponification treatment, and the blank organic phase can be recycled without acid washing operation.

Description

Mixed extraction agent and separation method for separating iron, aluminum and nickel-cobalt-magnesium in sulfuric acid leaching solution of nickel oxide ore

technical field

The invention relates to a nickel ore smelting method, in particular to a mixed extraction agent and a separation method for separating iron, aluminum, nickel, cobalt and magnesium in a nickel oxide ore sulfuric acid leach solution.

Background technique

Nickel oxide ore is the main resource of nickel ore. Acid leaching process is a common technology for smelting nickel oxide ore. Sulfuric acid leaching process is widely used in the wet smelting process of nickel oxide ore. The sulfuric acid leaching solution of nickel oxide ore contains a certain concentration of iron, aluminum, magnesium, nickel, cobalt and other metal ions. When the concentration of iron ions is high, iron removal is usually carried out first, and a certain concentration of iron still remains in the leaching solution after iron removal. In order to meet the impurity requirements of the subsequent cobalt-nickel electrolysis process, it is necessary to carry out deep iron removal through extraction and other impurity removal processes, and then use extraction methods to continue to separate nickel, cobalt, and magnesium; and the separation methods of aluminum and nickel-cobalt-magnesium in the leaching solution are relatively poor. few.

Solvent extraction technology has become a common method for separating metal ions due to its advantages of high selectivity, high recovery, simple process, continuous operation and easy automation. Acidic organophosphorus (phosphine) extractants are common extractants used in the separation of metal ions in sulfate solutions. Typical extractants include di(2-ethylhexyl)phosphonic acid (P204), 2-ethylhexylphosphonic acid 2-ethylhexyl ester (P507), bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272), etc. P204 is cheap and has strong extraction ability at low pH value, and is mostly used for impurity removal treatment of acid leaching solution (such as iron, copper and other impurities); Cyanex272 is developed and produced by American cyanamide company, which is expensive and rarely large-scale industrial Application: P507 is cheap, and its ability to extract and separate cobalt and nickel is higher than that of P204, and it is mostly used for the separation of cobalt and nickel under high pH conditions (pH>3). For the sulfuric acid leaching solution of nickel oxide ore or the leaching solution after iron removal, the pH value is mostly <2, so it is more appropriate to use P204 as the extraction and separation agent for iron. Therefore, P204 is selected as the extraction agent for the impurity removal (iron removal) operation of most nickel oxide ore acid leaching solutions. In addition, P204 can also extract aluminum under low pH conditions, so P204 can also be used as an extraction and separation agent for iron-aluminum and nickel-cobalt-magnesium.

When P204 reacts with metal ions, the H+ of the extractant will transfer to the water phase to increase the acidity of the water phase. In order to avoid the increase of the acidity of the water phase from affecting the extraction rate, P204 should be saponified with alkaline substances such as ammonia (or ammonium salt), NaOH, etc. It can ensure that the acidity of the extraction process remains unchanged. However, the saponification process will inevitably produce ammonia nitrogen wastewater or wastewater containing sodium ions. First, these wastewaters need to be treated before they can be discharged, otherwise they will cause environmental pollution; cost increase.

Another defect of P204 extraction and separation of metal ions is that stripping is difficult, and the concentration of stripping acid required is very high. For example, in the invention patent with the publication number CN102010999A, P204-kerosene is used as the extraction agent, and 5-8 mol/L hydrochloric acid is required. Back-extraction and removal of iron from the loaded organic phase; another example is the invention patent with the publication number CN102010993A, which uses 3-6 mol/L hydrochloric acid to back-extract the loaded organic phase including P204 to remove iron and other impurities in the organic phase. As a result, the residual acid in the blank organic phase after stripping is high, and it needs to be washed with water in multiple stages to remove the entrained acid or it can be recycled after adding an excessive amount of alkali to neutralize the acid. This not only prolongs the extraction process, but also Increased consumption of water or lye.

Contents of the invention

The technical problem to be solved by the present invention is to provide a mixed extraction agent and a separation method for separating iron, aluminum and nickel-cobalt-magnesium in the sulfuric acid leaching solution of nickel oxide ore. Using the extractant of the present invention to separate iron, aluminum and nickel-cobalt-magnesium in the sulfuric acid leaching solution of nickel oxide ore does not need to saponify the extractant in advance, while shortening the extraction cycle and reducing costs, it can also realize the extraction of nickel oxide ore sulfuric acid Separation of iron, aluminum and nickel-cobalt-magnesium in leach solution.

The mixed extractant used for separating iron, aluminum and nickel-cobalt-magnesium in the sulfuric acid leaching solution of nickel oxide ore according to the present invention is calculated by volume percentage, and the mixed extractant consists of 10-50% di(2-ethylhexyl)phosphonic acid (P204), 10-40% amine extractant and the remainder of the solvent composition.

Preferably, the above-mentioned mixed extractant is composed of 20-40% bis(2-ethylhexyl)phosphonic acid, 15-35% amine extractant and the balance of solvent by volume percentage.

In the technical scheme of the above mixed extractant, the amine extractant is a trialkyl tertiary amine (N235) or a secondary carbon primary amine (N1923).

In the technical scheme of the above-mentioned mixed extractant, the solvent is a conventional choice in the prior art, specifically, it can be one or more than two kinds selected from sulfonated kerosene, n-octane, n-octanol and n-heptane The combination. When the choice of solvent is a combination of any two of the above, the ratio between them can be any ratio.

The present invention also includes the method for separating iron, aluminum and nickel-cobalt-magnesium in the sulfuric acid leaching solution of nickel oxide ore by using the above-mentioned mixed extractant, including the extraction section treatment process, the washing section treatment process and the stripping section treatment process, and the organic phase and the water phase are continuously countercurrent Extraction, washing and stripping, where:

In the treatment process of the extraction section, the mixed extractant is used as the organic phase, and the mixed extractant and nickel oxide ore sulfuric acid leaching solution are respectively added from the entrance of the first stage of the extraction section and the entrance of the last stage of the extraction section; wherein, the mixed The extractant consists of 10-50% bis(2-ethylhexyl)phosphonic acid, 10-40% amine extractant and the rest of the solvent by volume percentage; the iron concentration in the sulfuric acid leaching solution of nickel oxide ore ≤3g/L, when the iron concentration in the nickel oxide ore sulfuric acid leaching solution is greater than 3g/L, the leaching solution is subjected to conventional iron removal operations to make the iron concentration ≤3g/L; in this process, the flow rate of the organic phase and the nickel oxide ore sulfuric acid leaching solution The ratio is 5～0.5:1～5;

In the treatment process of the washing section, the liquid flowing out from the outlet of the last stage of the extraction section is used as the organic phase, which is directly sent to the inlet of the first stage of the washing section; water is used as the water phase, and the water is sent from the inlet of the last stage of the washing section Add; in this process, the flow ratio of the organic phase to the aqueous phase is 10～0.5:1～10;

In the treatment process of the stripping section, the liquid flowing out from the outlet of the last stage of the washing section is used as the organic phase, which is directly sent to the inlet of the first stage of the stripping section; the dilute sulfuric acid is used as the water phase, and the dilute sulfuric acid is taken from the stripping section The inlet of the last stage is added; in this process, the flow ratio of the organic phase to the water phase is 10-0.5:1-10;

After continuous countercurrent extraction, washing and back-extraction processes, the solution containing nickel, cobalt and magnesium is discharged from the first-stage outlet of the extraction section, the aluminum sulfate solution is discharged from the first-stage outlet of the washing section, and the iron sulfate is discharged from the first-stage outlet of the stripping section. The solution and the blank mixed extractant are discharged from the last stage outlet of the stripping section.

In the above method, in the stripping section treatment process, the dilute sulfuric acid may be a sulfuric acid with a concentration lower than 1 mol/L, preferably a dilute sulfuric acid with a concentration of 0.01-1 mol/L.

In the above method, in the composition of the mixed extractant, the amine extractant is a trialkyl tertiary amine or a secondary carbon primary amine, and the solvent is a conventional choice in the prior art, specifically, it can be selected One or a combination of two or more of self-sulfonated kerosene, n-octane, n-octanol and n-heptane. When the choice of solvent is a combination of any two of the above, the ratio between them can be any ratio. In the present application, the mixed extractant is preferably composed of 20-40% bis(2-ethylhexyl)phosphonic acid, 15-35% amine extractant and the rest solvent in volume percentage.

In the above method, in the treatment process of the extraction section, the flow ratio of the organic phase to the nickel oxide ore sulfuric acid leaching solution is preferably 3-1:1-4.

In the above method, in the washing stage treatment process, the flow ratio of the organic phase to the water phase is preferably 7-0.5:1-6.

In the above method, in the stripping section treatment process, the flow ratio of the organic phase to the aqueous phase is preferably 3-0.5:1-7.

In the method of the present invention, the pH value of the nickel oxide ore sulfuric acid leaching solution is between -2 and 2, which contains nickel, cobalt, magnesium, iron (including ferrous ions and ferric ions) , aluminum and other metal ions, their concentrations are in the following ranges: nickel 0.5-3g/L, magnesium 3-25g/L, cobalt 0.01-0.2g/L, iron 0.01-3g/L, aluminum 0.5-15g /L. When iron > 3g/L (as iron content is 3～45g/L) in nickel oxide ore sulfuric acid leaching solution, it is necessary to carry out conventional deironing operation to leaching solution so that iron content ≤ 3g/L when just being suitable for using the method of the present invention to separate. The conventional iron removal operation can be the iron removal method commonly used in the prior art leachate, such as oxidation neutralization method, jarosite method, goethite method and hematite method and the like.

In the method of the present invention, the equipment used in the extraction section treatment process, the washing section treatment process and the stripping section treatment process is the same, specifically, it can be an extraction tower, a centrifugal extractor or a mixing-clarifying extractor, each processing There are several stages of extraction towers, centrifugal extractors or mixing-clarifying extractors in the process according to the needs.

In the method of the present invention, iron and aluminum are extracted by the sulfuric acid leaching solution of nickel oxide ore in the extraction section after countercurrent extraction, and the organic phase containing iron and aluminum enters the washing section through the last stage of the extraction section, and the remaining nickel-cobalt-magnesium-containing The aqueous phase is discharged from the outlet of the first stage of the extraction section; the organic phase containing iron and aluminum is washed with water in the washing section, and the aluminum is washed into the aqueous phase and discharged from the outlet of the first stage of the washing section, while the organic phase containing iron The organic phase enters the stripping section from the last stage of the washing section for continuous countercurrent stripping to strip the iron from the organic phase and discharge it from the outlet of the first stage of the stripping section. The organic phase is discharged from the outlet of the last stage of the stripping section. The obtained organic phase has a high pH value and can be directly sent to the inlet of the first stage of the extraction section for recycling without acid washing. When the iron content in the nickel oxide ore sulfuric acid leaching solution is less than or equal to 3g/L, the number of stages of the extraction section in the method of the present invention is 1 to 3, the number of washing sections is 1 to 3, and the number of stripping sections is 1 ~3 stages can achieve a good separation effect of iron, aluminum and nickel-cobalt-magnesium. In the sulfuric acid solution containing nickel, cobalt and magnesium obtained from the first stage outlet of the extraction section, the concentration of iron is lower than 0.0001g/L, and the concentration of aluminum is less than 0.0001g/L. The concentration of nickel, cobalt, magnesium, and iron in the aluminum sulfate solution obtained from the first-stage outlet of the washing section are respectively lower than 0.0001g/L, 0.0001g/L, 0.009g/L, 0.009g/L; in the ferric sulfate solution obtained by the first stage outlet of the stripping section, the concentration of aluminum is lower than 0.009g/L; the blank organic phase obtained by the last stage outlet of the stripping section (i.e. blank mixed extractant) pH value>5.

Compared with the prior art, the present invention has the advantages of:

1. There is no need to saponify P204, the step of ammonia (sodium) soap is omitted, and the treatment and discharge of ammonia nitrogen wastewater or wastewater containing sodium ions is avoided.

2. After using the mixed extractant to replace the existing P204-kerosene extractant system, the extraction ability of the mixed extractant system for iron is enhanced, the separation coefficient of iron to aluminum is significantly improved, and the separation coefficient of iron and aluminum to nickel, cobalt and magnesium is also significant Increase, shorten the number of extraction and washing stages, and improve the separation efficiency.

3. The detergent uses water instead of dilute acid, and the stripping agent uses dilute acid with extremely low concentration instead of high-concentration acid, so that the acid consumption of the entire extraction and separation process is greatly reduced. The residual acid content in the agent) is very low, and it can be returned to the extraction section for recycling without acid washing operation.

4. The suitable pH range for P204 to extract iron and aluminum is 1 to 2. When the pH value of the feed liquid is lower than 1, an alkaline substance needs to be added for pre-neutralization. When using the mixed extractant of the present invention, Even if the pH value of the feed liquid is lower than 1, there is no need to neutralize the acidity of the feed liquid, thereby avoiding the consumption of alkaline substances in the extraction process.

5. When the iron concentration in the pickling solution is high, most of the iron can be removed first through the iron removal process, and then the residual iron can be further removed through extraction and separation; when the iron concentration in the pickling solution is low, the iron removal process can be omitted and directly enter The extraction process separates iron; therefore, the separation method of the present invention is applicable to the separation of iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solutions from different sources.

6. Compared with the existing separation methods of iron, aluminum and nickel-cobalt-magnesium, the method of the present invention has shorter process flow, less reagent consumption, lower cost, and will not cause environmental pollution.

Description of drawings

Fig. 1 is a process flow diagram of the present invention, wherein A represents the first stage of the extraction section, a represents the last stage of the extraction section; B represents the first stage of the washing section, and b represents the last stage of the washing section; C represents the first stage of the stripping section level, c represents the last level of stripping section.

Detailed ways

Below in conjunction with specific embodiment the present invention is described in further detail, to understand the present invention better, but the present invention is not limited to following embodiment.

Embodiment 1: mixed extractant

According to volume percentage, measure 10% of P204, 20% of N235, 10% of n-octanol, 10% of n-octane and 50% of sulfonated kerosene, and mix them uniformly to obtain a mixed extractant.

Embodiment 2: mixed extractant

Measure 40% of P204, 10% of N235, and 50% of sulfonated kerosene by volume percentage, and mix them uniformly to obtain a mixed extractant.

Embodiment 3: mixed extractant

According to volume percentage, measure 30% of P204, 40% of N1923, 15% of n-heptane and 15% of sulfonated kerosene, and mix them uniformly to obtain a mixed extractant.

Embodiment 4: mixed extractant

According to volume percentage, measure 50% of P204, 15% of N1923 and 35% of n-octane, and mix uniformly to obtain a mixed extractant.

Embodiment 5: mixed extractant

According to volume percentage, measure 50% of P204, 40% of N235 and 10% of n-octane, and mix uniformly to obtain a mixed extractant.

Embodiment 6: adopt the method for separating iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solution with mixed extractant

The concentrations of iron, nickel, cobalt, magnesium and aluminum in the sulfuric acid leaching solution of nickel oxide ore are 41.5g/L, 1.03g/L, 0.09g/L, 4.3g/L and 1.89g/L respectively, and the pH value of the stock solution is -0.3, using the hematite method to remove iron, the concentration of iron in the obtained solution after iron removal is 2.9g/L, and the pH value of the solution is 1.1. The mixed extractant prepared in Example 1 is added from the entrance of the first stage of the extraction section, the solution after iron removal is added from the entrance of the last stage of the extraction section, water is added from the entrance of the last stage of the washing section, and the concentration is 0.4mol/L dilute sulfuric acid is added from the inlet of the last stage of the stripping section for countercurrent extraction, washing and stripping. Control the flow ratio of the mixed extractant in the extraction section to the solution after iron removal to 1:1, control the flow ratio of the organic phase to water in the washing section to 1:2.5, and control the flow ratio of the organic phase to dilute sulfuric acid in the stripping section to 5:1 . After 2 stages of extraction, 2 stages of washing and 2 stages of back extraction, a sulfuric acid solution containing nickel, cobalt and magnesium is obtained at the first stage of the extraction section, in which the concentrations of iron and aluminum are all lower than 0.00002g/L; in the first stage of the washing section The aluminum sulfate solution is obtained at the outlet, in which the concentrations of nickel, cobalt, magnesium, and iron are lower than 0.0005g/L, 0.0001g/L, 0.0003g/L, and 0.00004g/L respectively; iron sulfate is obtained at the first-stage outlet of the stripping section A solution in which the concentration of aluminum is less than 0.0001 g/L. The blank organic phase obtained from the last stage of the stripping section has a pH value of 5.9, which can be directly injected into the first stage of the extraction section for recycling.

The flow chart of the whole process is shown in Figure 1.

Embodiment 7: adopt the method for separating iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solution with mixed extractant

The concentrations of iron, nickel, cobalt, magnesium and aluminum in the sulfuric acid leaching solution of nickel oxide ore were 24.5g/L, 0.93g/L, 0.109g/L, 14.8g/L and 5.89g/L respectively, and the pH of the stock solution was 0.3, using the hematite method to remove iron, the concentration of iron in the obtained solution after iron removal is 1.5g/L, and the pH value of the solution is 1.6. The mixed extractant prepared in Example 2 is added from the entrance of the first stage of the extraction section, the solution after iron removal is added from the entrance of the last stage of the extraction section, water is added from the entrance of the last stage of the washing section, and the concentration is 0.1mol/L dilute sulfuric acid is added from the inlet of the last stage of the stripping section for countercurrent extraction, washing and stripping. Control the flow ratio of the mixed extractant in the extraction section to the solution after iron removal to 1:2, control the flow ratio of the organic phase to water in the washing section to 5:1, and control the flow ratio of the organic phase to dilute sulfuric acid in the stripping section to 2:5 . After 2 stages of extraction, 2 stages of washing and 1 stage of stripping, a nickel-cobalt-magnesium-containing sulfuric acid solution is obtained at the outlet of the first stage of the extraction section, in which the concentrations of iron and aluminum are all lower than 0.00003g/L; Aluminum sulfate solution is obtained at the outlet, wherein the concentrations of nickel, cobalt, magnesium, and iron are respectively lower than 0.0004g/L, 0.0003g/L, 0.0008g/L, and 0.00003g/L; ferric sulfate is obtained at the first-stage outlet of the stripping section A solution in which the concentration of aluminum is less than 0.0008 g/L. The blank organic phase obtained from the outlet of the last stage of the stripping section has a pH value of 6.1, which can be directly injected into the first stage of the extraction section for recycling.

Embodiment 8: adopt the method for separating iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solution with mixed extractant

The concentrations of iron, nickel, cobalt, magnesium and aluminum in the sulfuric acid leaching solution of nickel oxide ore were 7.5g/L, 2.13g/L, 0.19g/L, 20.8g/L and 8.89g/L respectively, and the pH of the stock solution was 1.4, adopt the goethite method to remove iron, the concentration of iron in the obtained solution after iron removal is 0.85g/L, and the pH value of the solution is 2.0. The mixed extractant prepared in Example 3 is added from the entrance of the first stage of the extraction section, the solution after iron removal is added from the entrance of the last stage of the extraction section, water is added from the entrance of the last stage of the washing section, and the concentration is 0.05mol/L dilute sulfuric acid is added from the inlet of the last stage of the stripping section for countercurrent extraction, washing and stripping. Control the flow ratio of the mixed extractant in the extraction section to the solution after iron removal to 1:3, control the flow ratio of the organic phase to water in the washing section to 0.5:3, and control the flow ratio of the organic phase to dilute sulfuric acid in the stripping section to 1:3 . After 1-stage extraction, 3-stage washing and 1-stage stripping, a sulfuric acid solution containing nickel, cobalt and magnesium is obtained at the first stage outlet of the extraction section, wherein the iron concentration is lower than 0.00003g/L, and the aluminum concentration is lower than 0.0004g/L; The aluminum sulfate solution is obtained from the first-stage outlet of the washing section, in which the concentrations of nickel, cobalt, magnesium, and iron are respectively lower than 0.00009g/L, 0.00003g/L, 0.0005g/L, and 0.00001g/L; The outlet of the second stage obtains a solution of ferric sulfate, in which the concentration of aluminum is lower than 0.0008g/L. The blank organic phase obtained from the last stage outlet of the stripping section has a pH value of 5.7, which can be directly injected into the first stage of the extraction section for recycling.

Embodiment 9: adopt the method for separating iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solution with mixed extractant

The concentrations of iron, nickel, cobalt, magnesium and aluminum in the sulfuric acid leaching solution of nickel oxide ore were 2.85g/L, 1.01g/L, 0.069g/L, 17.8g/L and 3.89g/L respectively, and the pH of the stock solution was 0.84. The mixed extractant prepared in Example 4 is added from the entrance of the first stage of the extraction section, the feed liquid is added from the entrance of the last stage of the extraction section, water is added from the entrance of the last stage of the washing section, and the concentration is 0.8mol /L of dilute sulfuric acid is added from the inlet of the last stage of the stripping section, and the solution after iron removal is subjected to countercurrent extraction, washing and stripping. Control the flow ratio of the mixed extractant in the extraction section to the solution after iron removal to 3:1, control the flow ratio of the organic phase to water in the washing section to 7:5, and control the flow ratio of the organic phase to dilute sulfuric acid in the stripping section to 1:3.5 . Through 2 stages of extraction, 3 stages of washing and 3 stages of stripping, the sulfuric acid solution containing nickel, cobalt and magnesium is obtained at the first stage outlet of the extraction section, wherein the iron concentration is lower than 0.00009g/L, and the aluminum concentration is lower than 0.00004g/L; The aluminum sulfate solution is obtained from the first-stage outlet of the washing section, in which the concentrations of nickel, cobalt, magnesium, and iron are respectively lower than 0.0001g/L, 0.00008g/L, 0.0009g/L, and 0.00001g/L; The outlet of the second stage is ferric sulfate solution, wherein the concentration of aluminum is lower than 0.0009g/L. The blank organic phase obtained from the last stage outlet of the stripping section has a pH value of 5.3, which can be directly injected into the first stage of the extraction section for recycling.

Embodiment 10: adopt the method for separating iron, aluminum and nickel-cobalt-magnesium in nickel oxide ore sulfuric acid leaching solution with mixed extractant

The concentrations of iron, nickel, cobalt, magnesium and aluminum in the sulfuric acid leaching solution of nickel oxide ore were 14.1g/L, 0.65g/L, 0.079g/L, 7.8g/L and 12.1g/L respectively, and the pH of the stock solution was 0.4, using the hematite method to remove iron, the concentration of iron in the obtained solution after iron removal is 1.05g/L, and the pH value of the solution is 2.2. The mixed extractant prepared in Example 5 is added from the entrance of the first stage of the extraction section, the solution after iron removal is added from the entrance of the last stage of the extraction section, water is added from the entrance of the last stage of the washing section, and the concentration is 0.03mol/L dilute sulfuric acid is added from the inlet of the last stage of the stripping section for countercurrent extraction, washing and stripping. Control the flow ratio of the mixed extractant in the extraction section to the solution after iron removal to 1:4, control the flow ratio of the organic phase to water in the washing section to 1:6, and control the flow ratio of the organic phase to dilute sulfuric acid in the stripping section to 3:7 . After 3 stages of extraction, 4 stages of washing and 2 stages of back extraction, the sulfuric acid solution containing nickel, cobalt and magnesium is obtained at the first stage of the extraction section, wherein the iron concentration is lower than 0.00003g/L, and the aluminum concentration is lower than 0.0001g/L; The aluminum sulfate solution is obtained from the first-stage outlet of the washing section, in which the concentrations of nickel, cobalt, magnesium, and iron are respectively lower than 0.00007g/L, 0.00001g/L, 0.0007g/L, and 0.00001g/L; The outlet of the second stage obtains a solution of ferric sulfate, in which the concentration of aluminum is lower than 0.0008g/L. The blank organic phase obtained from the last stage outlet of the stripping section has a pH value of 5.7, which can be directly injected into the first stage of the extraction section for recycling.

Claims (10)

1. for separating of the mixed extractant of iron, aluminium and nickel cobalt magnesium in nickel oxide ore sulphuric leachate, it is characterized in that: by volume percentages, this mixed extractant by 10 ~ 50% two (2-ethylhexyl) phosphonic acids, the amine extractant of 10 ~ 40% and the solvent composition of surplus.

2. the mixed extractant for separating of iron, aluminium and nickel cobalt magnesium in nickel oxide ore sulphuric leachate according to claim 1, it is characterized in that: by volume percentages, this mixed extractant by 20 ~ 40% two (2-ethylhexyl) phosphonic acids, the amine extractant of 15 ~ 35% and the solvent composition of surplus.

3. the mixed extractant for separating of iron, aluminium and nickel cobalt magnesium in nickel oxide ore sulphuric leachate according to claim 1 and 2, is characterized in that: described amine extractant is trialkyl tertiary amine or secondary carbon primary amine.

4. the mixed extractant for separating of iron, aluminium and nickel cobalt magnesium in nickel oxide ore sulphuric leachate according to claim 1 and 2, is characterized in that: described solvent is one or more the combination be selected from sulfonated kerosene, octane, n-Octanol and normal heptane.

5. adopt the method for iron, aluminium and nickel cobalt magnesium in mixed extractant separation of oxygenated nickel minerals sulphuric leachate according to claim 1, comprise extraction section treatment process, washing section treatment process and stripping section treatment process, organic phase and aqueous phase carry out continuous countercurrent extraction, washing and back extraction, it is characterized in that:

In extraction section treatment process, take mixed extractant as organic phase, mixed extractant and nickel oxide ore sulphuric leachate are added from the entrance of extraction section the 1st grade and the entrance of extraction section last step respectively; Wherein, described mixed extractant by volume percentages, two (2-ethylhexyl) phosphonic acids by 10 ~ 50%, the amine extractant of 10 ~ 40% and the solvent composition of surplus; Concentration of iron≤3g/L in described nickel oxide ore sulphuric leachate, when in nickel oxide ore sulphuric leachate during concentration of iron > 3g/L, carries out conventional deironing operation and makes wherein concentration of iron≤3g/L by leach liquor; In this operation, the throughput ratio of organic phase and nickel oxide ore sulphuric leachate is 5 ~ 0.5:1 ~ 5;

In washing section treatment process, with the liquid flowed out from the outlet of extraction section last step for organic phase, directly send into the entrance of washing section the 1st grade; Take water as aqueous phase, the entrance of water from washing section last step is added; In this operation, the throughput ratio of organic phase and aqueous phase is 10 ~ 0.5:1 ~ 10;

In stripping section treatment process, with the liquid flowed out from the outlet of washing section last step for organic phase, directly send into the entrance of stripping section the 1st grade; Take dilute sulphuric acid as aqueous phase, the entrance of dilute sulphuric acid from stripping section last step is added; In this operation, the throughput ratio of organic phase and aqueous phase is 10 ~ 0.5:1 ~ 10;

After continuous countercurrent extraction, washing and back extraction, the solution of nickel and cobalt containing magnesium is discharged from extraction section the 1st grade outlet, discharge alum liquor from washing section the 1st grade outlet, discharge ferrum sulfuricum oxydatum solutum from stripping section the 1st grade outlet, blank mixed extractant is exported by stripping section last step and discharges.

6. method according to claim 5, is characterized in that: in stripping section treatment process, and the concentration of described dilute sulphuric acid is 0.01 ~ 1mol/L.

7. the method according to claim 5 or 6, is characterized in that: by volume percentages, described mixed extractant by 20 ~ 40% two (2-ethylhexyl) phosphonic acids, the amine extractant of 15 ~ 35% and the solvent composition of surplus.

8. the method according to claim 5 or 6, is characterized in that: in extraction section treatment process, and the throughput ratio of organic phase and nickel oxide ore sulphuric leachate is 3 ~ 1:1 ~ 4.

9. the method according to claim 5 or 6, is characterized in that: in washing section treatment process, and the throughput ratio of organic phase and aqueous phase is 7 ~ 0.5:1 ~ 6.

10. the method according to claim 5 or 6, is characterized in that: in stripping section treatment process, and the throughput ratio of organic phase and aqueous phase is 3 ~ 0.5:1 ~ 7.