Extracting agent as well as preparation method and application thereof

Abstract

The invention discloses an extraction agent as well as a preparation method and application thereof. The extraction agent comprises a phosphorus or phosphine compound extraction agent and an extraction inhibitor, the extraction inhibitor is a weak acid compound selected from nonyl phenol, octyl phenol, 3, 5-di-tert-butyl catechol, 4-tert-butyl catechol, 4-butyl catechol, capryloyl salicylic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-hexyldecanoic acid, lauric acid, decanoic acid, 2, 2 '-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2'-(1, 4-phenylene bis (oxy)) divaleric acid, 2, 2 '-(1, 4-phenylene bis (oxy)) divaleric acid, 2, 2'-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2 '-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2'-( the organic solvent is at least one of 2, 2 '-(1, 4-phenylene bis (oxy)) dihexanoic acid, neodecanoic acid, 2, 2'-(1, 4-phenylene bis (oxy)) diheptanoic acid or 2, 2 '-(1, 4-phenylene bis (oxy)) dioctanoic acid. The extraction agent provided by the invention can effectively prevent an extraction system from generating emulsification or three phases, and can effectively improve the reverse extraction efficiency. In addition, the extraction agent can be designed and adjusted, the composition of the extraction agent can be adjusted according to the composition, element concentration and the like of the solution, and then efficient separation of metal elements is achieved.

Description

Technical Field

[0001] The invention relates to the field of scandium separation, and in particular to an extractant and a preparation method and application thereof. Background Art

[0002] Scandium is a rare earth element with unique physical and chemical properties. It is an indispensable and important element in the fields of national defense, military industry, aerospace, and electronic information. It is also one of my country's strategic key metal elements. Scandium is extremely sparsely distributed in the earth's crust, and independent minerals are rare. It is usually associated with rare earth ores, bauxite, laterite nickel ore, tungsten ore, and vanadium-titanium magnetite. Its extraction and separation are difficult and the process is complicated. Acidic phosphorus (phosphine) extractants P204, P507, and Cyanex272 have excellent extraction ability for scandium and strong selectivity. They can effectively separate scandium from most transition metal elements (such as Co, Ni, Cu, Mn, Fe, Zn, etc.) and lanthanide elements. However, phosphorus or phosphine compound extractants are prone to emulsification or third phase after extracting scandium, and are difficult to strip and regenerate. It is often necessary to use strong acid for multi-stage stripping, or use sodium hydroxide solution for precipitation stripping. The acid and alkali consumption is large, and the production process is difficult to control. Isooctyl alcohol and tributyl phosphate (TBP) are often used as phase modifiers in phosphorus or phosphine compound extractant systems, which can effectively avoid emulsification or the third phase in the extraction system. However, TBP and isooctyl alcohol are highly water-soluble, which will lead to a high content of organic matter in the raffinate, causing adverse effects on subsequent production processes. Summary of the invention

[0003] In order to improve the above technical problems, the present invention provides an extractant, comprising a phosphorus or phosphine compound extractant and an extractant inhibitor;

[0004] The extractant inhibitor is a weakly acidic compound, selected from at least one of nonylphenol, octylphenol, 3,5-di-tert-butylcatechol, 4-tert-butylcatechol, 4-butylcatechol, octanoyl salicylic acid, azelaic acid, sebacic acid, lauric acid, 2-hexyldecanoic acid, lauric acid, capric acid, 2,2'-(1,4-phenylenebis(oxy))dibutyric acid, 2,2'-(1,4-phenylenebis(oxy))divaleric acid, 2,2'-(1,4-phenylenebis(oxy))dihexanoic acid, neodecanoic acid, 2,2'-(1,4-phenylenebis(oxy))diheptanoic acid or 2,2'-(1,4-phenylenebis(oxy))dioctanoic acid.

[0005] According to an embodiment of the present invention, the phosphorus or phosphine compound extractant is selected from C 8-24 Alkyl-phosphinic acid, for example, the phosphorus or phosphine compound extractant includes, but is not limited to, at least one of di(2,4,4'-trimethylpentyl)phosphinic acid (Cyanex 272) and di(2-ethylhexyl)phosphinic acid (P227).

[0006] According to an embodiment of the present invention, the extractant also includes a co-solvent, which accounts for 0%-50% of the total volume of the phosphorus or phosphine compound extractant and the depressant, preferably 5%-50%, and exemplary are 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%.

[0007] According to an embodiment of the present invention, the cosolvent is a carboxylic acid ester compound, including but not limited to at least one of methyl 2-ethylhexanoate, ethyl 2-ethylhexanoate, n-propyl 2-ethylhexanoate, dioctyl terephthalate, (2-methylpentyl) benzoate, 2-ethylhexyl benzoate, isopentyl benzoate, bis(2-ethylhexyl) isophthalate, n-hexyl benzoate, methyl oleate, methyl laurate, ethyl laurate, oleyl oleate and lauryl laurate.

[0008] According to an embodiment of the present invention, the volume ratio of the phosphorus or phosphine compound extractant to the extraction inhibitor is 1:10-10:1, preferably 1:0.5-5.

[0009] According to an embodiment of the present invention, the extractant further comprises a diluent, and the diluent is selected from at least one of sulfonated kerosene, toluene, n-heptane, n-hexane and cyclohexane. The volume ratio of the diluent to the depressant is 4:1-20:1, preferably 5:1-15:1.

[0010] According to an embodiment of the present invention, the extractant is used for extracting, separating and purifying scandium, indium, uranium, thorium or lanthanide elements, etc., preferably for extracting, separating and purifying scandium.

[0011] The present invention also provides a method for preparing the above-mentioned extractant, which comprises:

[0012] The extractant is obtained by mixing a phosphorus or phosphine compound extractant, an extractant inhibitor and an optionally added co-solvent.

[0013] According to an embodiment of the present invention, a diluent is further added to the method, and the diluent is selected from at least one of sulfonated kerosene, toluene, n-heptane, n-hexane and cyclohexane.

[0014] According to an embodiment of the present invention, the volume ratio of the diluent to the extraction inhibitor is 4:1-20:1, preferably 5:1-15:1.

[0015] In the present invention, the temperature and time for preparing the extractant are not particularly limited, as long as the raw materials are mixed uniformly.

[0016] As an exemplary embodiment of the present invention, the method is specifically:

[0017] The phosphorus or phosphine compound extractant is mixed with an extractant inhibitor, then dissolved in a diluent, and then a co-solvent is added to obtain an extractant.

[0018] The present invention also provides the use of the above extractant in extracting, separating and purifying metal elements, wherein the metal elements are selected from scandium, indium, uranium, thorium or lanthanide elements, and is preferably used for extracting, separating and purifying scandium.

[0019] The present invention also provides a method for extracting and separating metal elements, comprising:

[0020] (1) mixing the extractant with the metal element-containing leaching solution for extraction, so that the metal element enters the organic phase;

[0021] (2) The organic phase obtained in step (1) is stripped using a stripping agent to separate the metal elements.

[0022] According to an embodiment of the present invention, in step (1), the metal element-containing leaching solution includes but is not limited to tungsten slag leaching solution, metal element-containing leaching solution produced in the production process of laterite nickel ore, red mud leaching solution, etc. The leaching solution contains the metal element to be extracted, scandium, indium, uranium, thorium or lanthanide.

[0023] According to an embodiment of the present invention, in step (1), the pH value of the metal element-containing leaching solution is 0-6.

[0024] According to an embodiment of the present invention, in step (1), during the extraction process, the volume ratio of the organic phase to the metal element-containing leaching solution is 1:10 to 10:1.

[0025] According to an embodiment of the present invention, in step (1), the volume ratio of the extractant to the scandium-containing leaching solution is 1:0.1-10.

[0026] According to an embodiment of the present invention, in step (1), the extraction may be a multi-stage extraction.

[0027] According to an embodiment of the present invention, in step (1), the extraction time is 1-60 min, preferably 5-30 min.

[0028] According to an embodiment of the present invention, in step (2), the organic phase may be washed before back extraction, and the washing liquid used in the washing process is an acid; the acid is, for example, hydrochloric acid, sulfuric acid or nitric acid solution, and the acid concentration is 0.01 mol / L to 6 mol / L.

[0029] According to an embodiment of the present invention, the volume ratio of the organic phase to the washing liquid in the washing process is 1:10 to 10:1;

[0030] According to an embodiment of the present invention, in step (2), the stripping agent is at least one of water, hydrochloric acid, sulfuric acid, nitric acid, a short-chain organic acid (such as formic acid, acetic acid, citric acid, lactic acid, malic acid, etc.), an organic acid salt and EDTA.

[0031] According to an embodiment of the present invention, the concentration of the stripping agent is 0-8 mol / L.

[0032] According to an embodiment of the present invention, during the stripping process, the volume ratio of the stripping agent to the organic phase is 1:10 to 10:1.

[0033] According to an embodiment of the present invention, in step (2), the stripping may be a multi-stage stripping, for example, 2 to 10 stages.

[0034] Beneficial Effects

[0035] The present invention provides an extractant and a preparation method thereof. Compared with the prior art, the extractant of the present invention can effectively avoid the emulsification or three-phase generation of the extraction system, and can effectively improve the stripping efficiency. In addition, the extractant described in the present invention can be designed and adjusted, and the composition of the extractant can be adjusted according to the composition of the solution, the element concentration, etc. For example, if the scandium concentration is high, the extraction system is easy to emulsify, and the proportion of the co-solvent can be appropriately increased to reduce the emulsification of scandium; the present invention can increase the stripping rate of scandium by increasing the proportion of the depressant, thereby realizing the efficient separation of metal elements (especially scandium).

[0036] The extractant preparation method of the present invention is simple, does not require additional saponification treatment, is easy to strip and regenerate, effectively reduces the consumption of acid and alkali, has a stable extraction system, does not produce emulsification and three phases, and is economical, environmentally friendly and efficient. DETAILED DESCRIPTION

[0037] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0038] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0039] Embodiment 1:

[0040] First, Cyanex272, neodecanoic acid, 2-ethylhexyl benzoate and sulfonated kerosene were measured and mixed evenly in a volume ratio of 1:1:0.1:10 to obtain an extractant for separation and purification of scandium.

[0041] The extractant is mixed with the scandium-containing leachate for extraction. The concentrations of the elements in the scandium-containing leachate are shown in Table 1. The volume ratio of the extractant to the scandium-containing leachate is 1:1, single-stage extraction, and the extraction reaction time is 20 minutes. After the extraction equilibrium, the organic phase is washed with 0.2 mol / L sulfuric acid in a single stage, and then stripped with 3 mol / L sulfuric acid in two stages. During the stripping process, the volume ratio of the stripping solution to the organic phase is 1:1, and a crude product of scandium sulfate solution is obtained. The extraction rate of scandium is about 90%-95%. After two-stage stripping, the stripping rate of scandium exceeds 60%. The purity of scandium in the obtained crude product of scandium sulfate solution is greater than 98%, and the concentrations of the elements in the stripping solution are shown in Table 2. After 5-stage stripping, the regenerated extractant is reused 5 times, and the extraction rate of scandium is still about 85%-90%.

[0042] Table 1 Concentration of each element in the scandium-containing leaching solution (g / L)

[0043] element Zn Ni Co Mn Fe Mg Cu Sc Na concentration 6.452 81.17 21.42 9.236 0.005 1.903 4.679 0.755 0.171

[0044] Table 2 Concentration of each element in the stripping solution, (g / L)

[0045] element Zn Ni Co Mn Fe Mg Cu Sc Na First stage stripping 0.006 0.002 0 0 0 0 0 0.366 0 Second stage stripping 0 0 0 0 0 0 0 0.118 0

[0046] Embodiment 2:

[0047] First, Cyanex272, 2-hexyldecanoic acid, ethyl 2-ethylhexanoate and sulfonated kerosene were measured and mixed evenly in a volume ratio of 1:1:0.1:10 to obtain an extractant for separation and purification of scandium.

[0048] The extractant is mixed with the scandium-containing leachate for extraction, and the concentrations of each element in the scandium-containing leachate are shown in Table 1. The volume ratio of the extractant to the scandium-containing leachate for separation and purification of scandium is 1:1, single-stage extraction, and the extraction reaction time is 20 minutes. After the extraction equilibrium, the organic phase is washed with 0.2 mol / L sulfuric acid in a single stage, and then 3 mol / L sulfuric acid is used for two-stage stripping to obtain a crude product of scandium sulfate solution. The extraction rate of scandium is about 90%-95%. After two-stage stripping, the stripping rate of scandium exceeds 60%, and the purity of scandium in the obtained crude product of scandium sulfate solution is greater than 98%. After 5-stage stripping, the regenerated extractant is reused 5 times, and the extraction rate of scandium is still 85%-90%.

[0049] Embodiment 3:

[0050] First, Cyanex272, decanoic acid, methyl 2-ethylhexanoate and sulfonated kerosene were measured and mixed evenly in a volume ratio of 1:1:0.1:10 to obtain an extractant for separation and purification of scandium.

[0051] The extractant is mixed with the scandium-containing leachate for extraction. The concentrations of the elements in the scandium-containing leachate are shown in Table 1. The volume ratio of the extractant to the scandium-containing leachate for separation and purification of scandium is 1:1, single-stage extraction, and the extraction reaction time is 20 minutes. After the extraction equilibrium, the organic phase is washed with 0.2 mol / L sulfuric acid in a single stage, and then 3 mol / L sulfuric acid is used for two-stage stripping to obtain a crude product of scandium sulfate solution. The extraction rate of scandium is about 90%-95%. After two-stage stripping, the stripping rate of scandium exceeds 60%, and the purity of scandium in the obtained crude product of scandium sulfate solution is greater than 98%. After 5-stage stripping, the regenerated extractant is reused 5 times, and the extraction rate of scandium is still about 85%-90%.

[0052] Comparative Example 1:

[0053] Cyanex272 and sulfonated kerosene were uniformly mixed in a volume ratio of 1:10 to obtain an extractant for separation and purification of scandium.

[0054] The extractant is mixed with the scandium-containing leachate for extraction, and the concentration of each element in the scandium-containing leachate is shown in Table 1. The volume ratio of the extractant to the leachate is 1:1, single-stage extraction, and the extraction reaction time is 10 minutes. After the extraction equilibrium, the organic phase is washed with 0.2 mol / L sulfuric acid in a single stage, and then 3 mol / L sulfuric acid is used for two-stage stripping to obtain a crude product of scandium sulfate solution. The extraction rate of scandium is about 98%, and after two-stage stripping, the stripping rate of scandium does not exceed 40%. The concentration of each element in the stripping solution is shown in Table 3, and the stripping rate is significantly lower than that of Examples 1-3.

[0055] Table 3 Concentration of each element in the stripping solution, (g / L)

[0056] element Zn Ni Co Mn Fe Mg Cu Sc Na First stage stripping 0.040 0.002 0.001 0 0 0 0 0.143 0 Second stage stripping 0 0 0 0 0 0 0 0.068 0

[0057] The above is an exemplary description of the embodiments of the present invention. However, the protection scope of the present invention is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An extractant, characterized in that It includes a phosphorus or phosphine compound extractant and an extractant inhibitor; The extractant inhibitor is a weakly acidic compound, selected from at least one of nonylphenol, octylphenol, 3,5-di-tert-butylcatechol, 4-tert-butylcatechol, 4-butylcatechol, octanoyl salicylic acid, azelaic acid, sebacic acid, lauric acid, 2-hexyldecanoic acid, lauric acid, capric acid, 2,2'-(1,4-phenylenebis(oxy))dibutyric acid, 2,2'-(1,4-phenylenebis(oxy))divaleric acid, 2,2'-(1,4-phenylenebis(oxy))dihexanoic acid, neodecanoic acid, 2,2'-(1,4-phenylenebis(oxy))diheptanoic acid or 2,2'-(1,4-phenylenebis(oxy))dioctanoic acid.

2. The extractant according to claim 1, characterized in that The phosphorus or phosphine compound extractant is selected from C 8-24 The alkyl-phosphinic acid is preferably at least one of di(2,4,4'-trimethylpentyl)phosphinic acid and di(2-ethylhexyl)phosphinic acid. Preferably, the extractant further comprises a co-solvent, and the co-solvent accounts for 0%-50% of the total volume of the phosphorus or phosphine compound extractant and the extraction inhibitor. Preferably, the cosolvent is a carboxylic acid ester compound, including but not limited to at least one of methyl 2-ethylhexanoate, ethyl 2-ethylhexanoate, n-propyl 2-ethylhexanoate, dioctyl terephthalate, (2-methylpentyl) benzoate, 2-ethylhexyl benzoate, isopentyl benzoate, bis(2-ethylhexyl) isophthalate, n-hexyl benzoate, methyl oleate, methyl laurate, ethyl laurate, oleyl oleate and lauryl laurate.

3. The extractant according to claim 1 or 2, characterized in that The volume ratio of the phosphorus or phosphine compound extractant to the extraction inhibitor is 1:10-10:

1. Preferably, the extractant further comprises a diluent, and the diluent is selected from at least one of sulfonated kerosene, toluene, n-heptane, n-hexane and cyclohexane. Preferably, the volume ratio of the diluent to the depressant is 4:1-20:

1.

4. The method for preparing the extractant according to any one of claims 1 to 3, characterized in that: The method is: The extractant is obtained by mixing a phosphorus or phosphine compound extractant, an extractant inhibitor and an optionally added co-solvent.

5. The method according to claim 4, characterized in that A diluent is also added in the method, and the diluent is selected from at least one of sulfonated kerosene, toluene, n-heptane, n-hexane and cyclohexane. Preferably, the volume ratio of the diluent to the extraction inhibitor is 4:1-20:

1.

6. Use of the extractant according to any one of claims 1 to 3 in extracting, separating and purifying metal elements, wherein the metal elements are selected from scandium, indium, uranium, thorium or other rare earth elements, and is preferably used for extracting, separating and purifying scandium.

7. A method for extracting and separating metal elements, characterized in that: include: (1) mixing the extractant with the metal element-containing leaching solution for extraction, so that the metal element enters the organic phase; (2) stripping the organic phase obtained in step (1) using a stripping agent to separate the metal elements; The leaching solution contains the metal elements to be extracted, such as scandium, indium, uranium, thorium or lanthanide.

8. The method according to claim 7, characterized in that In step (1), during the extraction process, the volume ratio of the organic phase to the metal element-containing leaching solution is 1:10 to 10:

1. Preferably, in step (1), the volume ratio of the extractant to the scandium-containing leaching solution is 1:0.1-10.

9. The method according to claim 7 or 8, characterized in that: In step (2), the stripping agent is at least one of water, hydrochloric acid, sulfuric acid, nitric acid, a short-chain organic acid (such as formic acid, acetic acid, citric acid, lactic acid, malic acid, etc.), an organic acid salt and EDTA.

10. The method according to any one of claims 7 to 9, characterized in that: The concentration of the stripping agent is 0-8 mol / L. Preferably, during the stripping process, the volume ratio of the stripping agent to the organic phase is 1:10 to 10:1.