A method for stepwise extraction and separation and recovery of gallium, iron and rare earths from the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste

Abstract

The present invention relates to the technical field of hydrometallurgy, and specifically discloses a method for stepwise extraction and separation and recovery of gallium, iron and rare earths from a sulfuric acid leaching solution of electronic waste containing gallium and rare earths. This method cleverly utilizes the performance differences between the extraction and stripping effects of the mixed organic phases of N1923-sulfonated kerosene, TRPO-sulfonated kerosene, and bis(nonylphenyl) phosphate-sulfonated kerosene with gallium, iron, and rare earth elements in different acidic systems, and realizes the complete extraction and separation of gallium, iron and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths through stepwise extraction and stripping. This method has the advantages of simple operation, easy industrialization, environmental friendliness, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrometallurgy, and particularly to a method for stepwise extraction and separation to recover gallium, iron and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth. Background Art

[0002] Scattered metal gallium and rare earth are indispensable basic raw materials for the development of high-tech fields such as electronic information and advanced equipment. Due to the rapid development and replacement of high-tech fields, a large number of retired products have emerged. These retired electronic wastes contain a large amount of gallium and rare earth resources, and are considered important secondary resources for gallium and rare earth, and are even more renowned as urban minerals. To achieve the leaching of gallium and rare earth in these secondary resources, the sulfuric acid leaching method is a commonly used technology. During the acid leaching process, Ga and rare earth enter the sulfuric acid leaching solution, and at the same time, there is a relatively high concentration of Fe, as well as a small amount of elements such as Ni, Co, and Cu that are also leached. Therefore, how to achieve the separation and recovery of Ga, rare earth, and Fe in the leaching solution is of great significance for the resource utilization of electronic waste containing gallium and rare earth. Although the solvent extraction method is a commonly used and easy-to-operate method for the separation and extraction of metals in solution and is easy to industrialize, the current extraction agent system and extraction method are both difficult to be applicable to the extraction and separation of gallium, iron and rare earth in this leaching solution, which greatly restricts the comprehensive recovery and utilization of gallium, iron and rare earth in electronic waste containing gallium and rare earth.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The present invention solves the above problems existing in the prior art. The purpose of the present invention is to provide a method for stepwise extraction and separation to recover gallium, iron and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth, and realizes the efficient separation and recovery of gallium, iron and rare earth by the full extraction method directly from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth.

[0005] A method for stepwise extraction and separation to recover gallium, iron and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth proposed by the present invention includes the following steps:

[0006] (1) Using a first organic phase to perform cross-flow extraction with the sulfuric acid leaching solution of electronic waste containing gallium and rare earth to obtain a primary organic phase and a primary raffinate. The first organic phase is composed of N1923 and sulfonated kerosene. Among them, the sulfuric acid leaching solution of electronic waste containing gallium and rare earth contains Ga 3+ 1 - 2 g / L, Fe 3+ 5 - 10 g / L, rare earth ions 1 - 2 g / L, Ni 2+ , Co 2+ , Cu 2+ are all less than 1.0 g / L, and the pH value is 0 - 1.5;

[0007] (2) Perform counter-current stripping of the primary organic phase with hydrochloric acid to obtain a secondary organic phase and a gallium-iron-rare earth stripping solution. After the secondary organic phase is washed with a clarified lime water solution until the pH reaches 7, it is returned to step (1) as the primary organic phase for recycling.

[0008] (3) Perform counter-current extraction of the gallium-iron-rare earth stripping solution with a secondary organic phase to obtain a tertiary organic phase and a rare earth raffinate. The secondary organic phase consists of TRPO and sulfonated kerosene.

[0009] (4) Perform counter-current stripping of the tertiary organic phase with nitric acid to obtain a quaternary organic phase and a gallium-iron stripping solution. After the quaternary organic phase is washed with deionized water solution until the pH reaches 7, it is returned to step (3) as the secondary organic phase for recycling.

[0010] (5) Perform counter-current extraction of the gallium-iron stripping solution with a tertiary organic phase to obtain a quinary organic phase and a gallium raffinate. The tertiary organic phase consists of bis(nonylphenyl) phosphate and sulfonated kerosene.

[0011] (6) Perform counter-current stripping of the quinary organic phase with oxalic acid to obtain a senary organic phase and an iron stripping solution; after the senary organic phase is washed with deionized water solution until the pH reaches 7, it is returned to step (5) as the tertiary organic phase for recycling.

[0012] Preferably, the primary organic phase in step (1) consists of the following components by volume fraction: 10% - 20% N1923 and 80% - 90% sulfonated kerosene.

[0013] Preferably, in step (1), the extraction ratio O / A of the cross-flow extraction is 1 - 3:1, the number of extraction stages is 1 - 3, and the extraction time is 5 - 10 min.

[0014] Preferably, the concentration of the hydrochloric acid in step (2) is 5 - 6 mol / L, the stripping ratio A / O of the counter-current stripping is 1 - 3:1, the number of stripping stages is 2 - 3, and the stripping time is 5 - 10 min.

[0015] Preferably, the secondary organic phase in step (3) consists of the following components by volume fraction: 10% - 30% TRPO and 70% - 90% sulfonated kerosene.

[0016] Preferably, in step (3), the extraction ratio O / A of the counter-current extraction is 1 - 3:1, the number of extraction stages is 2 - 3, and the extraction time is 5 - 10 min.

[0017] Preferably, the molar concentration of the nitric acid in step (4) is 2 - 4 mol / L, the stripping ratio A / O of the counter-current stripping is 1 - 3:1, the number of stripping stages is 2 - 3, and the stripping time is 5 - 10 min.

[0018] Preferably, the third organic phase in step (5) is composed of the following components by volume fraction: 10% - 20% bis(nonylphenyl) phosphate and 80% - 90% sulfonated kerosene.

[0019] Preferably, for the countercurrent extraction in step (5), the extraction phase ratio O / A is 1 - 2:1, the number of extraction stages is 1 - 2, and the extraction time is 5 - 10 min.

[0020] Preferably, the molar concentration of the oxalic acid solution in step (6) is 0.5 - 1.0 mol / L: for the countercurrent stripping, the stripping phase ratio A / O is 1 - 2:1, the number of stripping stages is 3 - 5, and the stripping time is 5 - 10 min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The method provided by the present invention ingeniously utilizes the performance differences in the extraction and stripping effects of N1923 - sulfonated kerosene, TRPO - sulfonated kerosene, and bis(nonylphenyl) phosphate - sulfonated kerosene mixed organic phases with gallium, iron, and rare earth elements under different acidic systems. Through the step - by - step extraction and stripping methods, the complete extraction and separation of gallium, iron, and rare earth in the sulfuric acid leaching solution of electronic waste containing gallium and rare earth are realized. This method has the advantages of simple operation, easy industrialization, and environmental friendliness, providing technical support for the comprehensive recovery and utilization of the wet - process complete extraction of electronic waste containing gallium and rare earth. Detailed Embodiments

[0023] The following examples are further illustrations of the present invention rather than limitations. Unless otherwise specified, the equipment and reagents used in the present invention are conventional commercially available products in this technical field.

[0024] Example 1

[0025] The composition of the sulfuric acid leaching solution of electronic waste containing gallium and rare earth is shown in Table 1:

[0026] Table 1

[0027]

[0028] A method for step - by - step extraction and separation of gallium, iron, and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth, comprising the following steps:

[0029] (1) Using the first organic phase and the sulfuric acid leaching solution of electronic waste containing gallium and rare earth for 3 - stage cross - flow extraction with an extraction phase ratio O / A of 2:1 and an extraction time of 10 min, obtaining a primary organic phase and a primary raffinate. The extraction rates of gallium, iron, and rare earth are all 100%, and the extraction rate of other ions is <5%. By volume fraction, the first organic phase is composed of 10% N1923 + 90% sulfonated kerosene;

[0030] (2) Take the primary organic phase and 6 mol / L hydrochloric acid, with a stripping phase ratio of A / O of 1:1 and a stripping time of 10 min, and perform three-stage countercurrent stripping to obtain the secondary organic phase and the gallium-iron-rare earth stripping solution. The stripping rates of gallium, iron, and rare earth are all 100%. After the secondary organic phase is washed with clarified lime water solution until the pH = 7, it is returned to step (1) as the primary organic phase for recycling;

[0031] (3) Use the secondary organic phase and the gallium-iron-rare earth stripping solution, with an extraction phase ratio of O / A of 1:1 and an extraction time of 10 min, and perform three-stage countercurrent extraction to obtain the tertiary organic phase and the rare earth raffinate. The extraction rates of gallium and iron are both 100%, and the extraction rate of rare earth is only 2.07%. By volume fraction, the secondary organic phase consists of 30% TRPO and 70% sulfonated kerosene;

[0032] (4) Take the tertiary organic phase and 2 mol / L nitric acid, with a stripping phase ratio of A / O of 3:1 and a stripping time of 10 min, and perform two-stage countercurrent stripping to obtain the quaternary organic phase and the gallium-iron stripping solution. The stripping rate of gallium is 98.63% and the stripping rate of iron is 99.02%. After the quaternary organic phase is washed with deionized water solution until the pH = 7, it is returned to step (3) as the secondary organic phase for recycling;

[0033] (5) Use the tertiary organic phase and the gallium-iron stripping solution, with an extraction phase ratio of O / A of 1:1 and an extraction time of 10 min, and perform two-stage countercurrent extraction to obtain the quinary organic phase and the gallium raffinate. The extraction rate of iron is 98.05%, and the extraction rate of gallium is only 8.01%. By volume fraction, the tertiary organic phase consists of 10% bis(nonylphenyl) phosphate and 90% sulfonated kerosene;

[0034] (6) Take the quinary organic phase and 0.5 mol / L oxalic acid solution, with a stripping phase ratio of A / O of 1:1 and a stripping time of 10 min, and perform five-stage countercurrent stripping to obtain the senary organic phase and the iron stripping solution. The stripping rate of iron is 98.45%. After the senary organic phase is washed with deionized water solution until the pH = 7, it is returned to step (5) as the tertiary organic phase for recycling.

[0035] Example 2

[0036] The composition of the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste is shown in Table 2:

[0037] Table 2

[0038]

[0039] A method for stepwise extraction and separation and recovery of gallium, iron, and rare earth from the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste, comprising the following steps:

[0040] (1) The first organic phase and the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste are subjected to 1-stage cross-flow extraction with an extraction ratio of O / A of 1:1 and an extraction time of 10 min to obtain a primary organic phase and a primary raffinate. The extraction rates of aluminum, iron, and gallium are all 100%, and the extraction rates of other ions are <5% (by volume fraction). The first organic phase consists of 20% N1923 + 80% sulfonated kerosene;

[0041] (2) The primary organic phase and 6 mol / L hydrochloric acid are subjected to 3-stage counter-current stripping with a stripping ratio of A / O of 1:1 and a stripping time of 5 min to obtain a secondary organic phase and a gallium, iron, and rare earth stripping solution. The stripping rates of gallium, iron, and rare earth are all 100%. After the secondary organic phase is washed with a clarified lime water solution to pH = 7, it is returned to step (1) as the first organic phase for recycling;

[0042] (3) The second organic phase and the gallium, iron, and rare earth stripping solution are subjected to 2-stage counter-current extraction with an extraction ratio of O / A of 1:1 and an extraction time of 10 min to obtain a tertiary organic phase and a rare earth raffinate. The extraction rates of gallium and iron are both 100%, and the extraction rate of rare earth is only 1.73% (by volume fraction). The second organic phase consists of 30% TRPO + 70% sulfonated kerosene;

[0043] (4) The tertiary organic phase and 4 mol / L nitric acid are subjected to 3-stage counter-current stripping with a stripping ratio of A / O of 3:1 and a stripping time of 5 min to obtain a quaternary organic phase and a gallium and iron stripping solution. The gallium stripping rate is 99.27% and the iron stripping rate is 99.46%. After the quaternary organic phase is washed with deionized water solution to pH = 7, it is returned to step (3) as the second organic phase for recycling;

[0044] (5) The third organic phase and the gallium and iron stripping solution are subjected to 1-stage counter-current extraction with an extraction ratio of O / A of 1:1 and an extraction time of 10 min to obtain a quinary organic phase and a gallium raffinate. The iron extraction rate is 100%, and the gallium extraction rate is only 7.28% (by volume fraction). The third organic phase consists of 20% bis(nonylphenyl) phosphate + 80% sulfonated kerosene;

[0045] (6) The quinary organic phase and 0.5 mol / L oxalic acid solution are subjected to 3-stage counter-current stripping with a stripping ratio of A / O of 2:1 and a stripping time of 10 min to obtain a senary organic phase and an iron stripping solution. The iron stripping rate is 98.24%. After the senary organic phase is washed with deionized water solution to pH = 7, it is returned to step (5) as the third organic phase for recycling.

[0046] Example 3

[0047] The composition of the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste is shown in Table 3:

[0048] Table 3

[0049]

[0050] A method for stepwise extraction and separation to recover gallium, iron and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth, comprising the following steps:

[0051] (1) Using a first organic phase and the sulfuric acid leaching solution of electronic waste containing gallium and rare earth with an extraction ratio of O / A of 1:1 and an extraction time of 5 min, performing 2-stage cross-flow extraction to obtain a primary organic phase and a primary raffinate. The extraction rates of aluminum, iron and gallium are all 100%, and the extraction rates of other ions are <5% (by volume fraction). The first organic phase consists of 15% N1923 + 85% sulfonated kerosene;

[0052] (2) Taking the primary organic phase and 5 mol / L hydrochloric acid with a stripping ratio of A / O of 3:1 and a stripping time of 5 min, performing 2-stage counter-current stripping to obtain a secondary organic phase and a gallium, iron and rare earth stripping solution. The stripping rates of gallium, iron and rare earth are all 100%. After the secondary organic phase is washed with a clarified lime water solution to pH = 7, it is returned to step (1) as the first organic phase for recycling;

[0053] (3) Using a second organic phase and the gallium, iron and rare earth stripping solution with an extraction ratio of O / A of 3:1 and an extraction time of 5 min, performing 3-stage counter-current extraction to obtain a tertiary organic phase and a rare earth raffinate. The extraction rates of gallium and iron are both 100%, and the extraction rate of rare earth is only 2.33% (by volume fraction). The second organic phase consists of 30% TRPO and 70% sulfonated kerosene;

[0054] (4) Taking the tertiary organic phase and 3 mol / L nitric acid with a stripping ratio of A / O of 1:1 and a stripping time of 5 min, performing 3-stage counter-current stripping to obtain a quaternary organic phase and a gallium and iron stripping solution. The gallium stripping rate is 98.01% and the iron stripping rate is 98.21%. After the quaternary organic phase is washed with deionized water solution to pH = 7, it is returned to step (3) as the second organic phase for recycling;

[0055] (5) Using a third organic phase and the gallium and iron stripping solution with an extraction ratio of O / A of 2:1 and an extraction time of 5 min, performing 1-stage counter-current extraction to obtain a fifth organic phase and a gallium raffinate. The iron extraction rate is 99.23% and the gallium extraction rate is only 7.73% (by volume fraction). The third organic phase consists of 15% bis(nonylphenyl) phosphate and 85% sulfonated kerosene;

[0056] (6) Taking the fifth organic phase and 0.5 mol / L oxalic acid solution with a stripping ratio of A / O of 1:1 and a stripping time of 5 min, performing 5-stage counter-current stripping to obtain a sixth organic phase and an iron stripping solution. The iron stripping rate is 97.89%. After the sixth organic phase is washed with deionized water solution to pH = 7, it is returned to step (5) as the third organic phase for recycling.

[0057] Comparative Example 1

[0058] This comparative example is basically the same as Example 1, except that: in the first organic phase, the same type of extractant N235 is used to replace N1923, and the extraction rates of Ga and rare earths are both less than 30%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0059] Comparative Example 2

[0060] This comparative example is basically the same as Example 1, except that: nitric acid is used to replace hydrochloric acid, and the first organic phase is stripped with 6 mol / L nitric acid to obtain a stripping solution of Ga, Fe, and rare earths; the second organic phase is used to extract the stripping solution of Ga, Fe, and rare earths, and the extraction rates of Ga and Fe are both less than 15%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0061] Comparative Example 3

[0062] This comparative example is basically the same as Example 2, except that: in the second organic phase, the same type of extractant P350 is used to replace TRPO, the extraction rate of Fe is only 9.02%, and the extraction rate of Ga is only 68.93%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0063] Comparative Example 4

[0064] This comparative example is basically the same as Example 2, except that: sulfuric acid is used to replace nitric acid, and the third organic phase is stripped with 4 mol / L sulfuric acid to obtain a stripping solution of Ga and Fe; the third organic phase is used to extract the stripping solution of Ga and Fe, and the extraction rate of Fe is only 63.35%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0065] Comparative Example 5

[0066] This comparative example is basically the same as Example 3, except that: in the third organic phase, the same type of extractant Cyanex272 is used to replace bis(nonylphenyl) phosphate, and the extraction rate of Fe is only 42.73%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0067] Comparative Example 6

[0068] This comparative example is basically the same as Example 3, except that: nitric acid is used to replace oxalic acid, and the fifth organic phase is stripped with 0.5 mol / L nitric acid solution, and the extraction rate of Fe is only 11.29%, and the stepwise extraction and separation and recovery of Ga, Fe, and rare earths in the sulfuric acid leaching solution of electronic waste containing gallium and rare earths cannot be achieved.

[0069] By comparing the examples with each comparative example, it can be seen that none of the comparative examples can achieve the stepwise extraction and separation effect of gallium, iron, and rare earth in the examples. Thus, it can be demonstrated that the extraction system and extraction process for the stepwise extraction and separation and recovery of gallium, iron, and rare earth from the sulfuric acid leaching solution of electronic waste containing gallium and rare earth in the present invention are not simply a combination of extractants and extraction processes or a conventional substitution of the same type, but have an unexpected and significantly synergistic effect; and when the extraction method, number of stages, time, etc. are within the scope required by the present invention, the extraction and separation effects of each metal can be further ensured.

[0070] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction, separation and recovery, characterized in that: The steps include: (1) A first organic phase is used to perform cross-current extraction with a sulfuric acid leaching solution containing gallium and rare earth electronic waste to obtain a primary organic phase and a primary raffinate, wherein the first organic phase is composed of N1923 and sulfonated kerosene, wherein the sulfuric acid leaching solution containing gallium and rare earth electronic waste contains Ga 3+ 1~2 g / L, Fe 3+ 5~10 g / L, rare earth ions 1~2 g / L, Ni 2+ 、Co 2+ , Cu 2+ All are less than 1.0 g / L, and the pH value is 0~1.5; (2) taking the primary organic phase and conducting countercurrent stripping with hydrochloric acid to obtain a secondary organic phase and a gallium-iron-rare earth stripping solution, and washing the secondary organic phase with a clarified lime solution to a pH of 7 and then returning to step (1) for recycling as the first organic phase; (3) using the second organic phase and the gallium iron rare earth stripping solution to perform countercurrent extraction to obtain a tertiary organic phase and a rare earth raffinate, wherein the second organic phase is composed of TRPO and sulfonated kerosene; (4) taking the three organic phases and performing countercurrent stripping with nitric acid to obtain the fourth organic phase and gallium-iron stripping solution, washing the fourth organic phase with deionized water solution to pH = 7 and then returning to step (3) for recycling as the second organic phase; (5) using a third organic phase and a gallium-iron stripping solution to perform countercurrent extraction to obtain a fifth organic phase and a gallium raffinate, wherein the third organic phase is composed of di(nonylphenyl) phosphate and sulfonated kerosene; (6) taking the fifth organic phase and conducting countercurrent stripping with oxalic acid solution to obtain a sixth organic phase and an iron stripping solution; the sixth organic phase is washed with a deionized water solution to a pH of 7 and then returned to step (5) for recycling as the third organic phase; Wherein, the first organic phase in step (1) is composed of the following components by volume fraction: 10% to 20% N1923 and 80% to 90% sulfonated kerosene; The second organic phase in step (3) is composed of the following components by volume: 10% to 30% TRPO and 70% to 90% sulfonated kerosene; The third organic phase in step (5) is composed of the following components by volume: 10% to 20% of di(nonylphenyl) phosphate and 80% to 90% of sulfonated kerosene.

2. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The extraction phase ratio O / A of the cross-current extraction in step (1) is 1-3:1, the number of extraction stages is 1-3, and the extraction time is 5-10 min.

3. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The concentration of the hydrochloric acid in step (2) is 5-6 mol / L, the countercurrent stripping phase ratio A / O is 1-3:1, the stripping stage is 2-3, and the stripping time is 5-10 min.

4. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The countercurrent extraction in step (3) has an extraction phase ratio O / A of 1-3:1, an extraction stage of 2-3, and an extraction time of 5-10 min.

5. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The molar concentration of nitric acid in step (4) is 2-4 mol / L, the stripping phase ratio A / O of countercurrent stripping is 1-3:1, the stripping stage is 2-3, and the stripping time is 5-10 min.

6. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The countercurrent extraction in step (5) has an extraction phase ratio O / A of 1-2:1, an extraction stage of 1-2, and an extraction time of 5-10 min.

7. The method for recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth by stepwise extraction and separation according to claim 1, characterized in that: The molar concentration of the oxalic acid solution in step (6) is 0.5-1.0 mol / L: the stripping phase ratio A / O of the countercurrent stripping is 1-2:1, the stripping stage is 3-5, and the stripping time is 5-10 min.

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