Method for extracting, separating and recovering gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth step by step

Abstract

The invention relates to the technical field of hydrometallurgy, and particularly discloses a method for extracting, separating and recovering gallium, iron and rare earth from electronic waste sulfuric acid leachate containing gallium and rare earth step by step. According to the performance difference between the extraction effect and the reverse extraction effect of a mixed organic phase of N1923-sulfonated kerosene, TRPO-sulfonated kerosene and di (nonylphenyl) phosphate-sulfonated kerosene and gallium, iron and rare earth elements, total extraction separation of gallium, iron and rare earth in the sulfuric acid leaching solution of the electronic waste containing gallium and rare earth is achieved in a step-by-step extraction and reverse extraction mode. The method has the advantages of simplicity and convenience in operation, easiness in industrialization, environment friendliness and the like.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for step-by-step extraction, separation and recovery of gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth. Background Art

[0002] Both scattered metal gallium and rare earth are strategic metal resources in my country, and are also indispensable basic raw materials for the development of high-tech fields such as electronic information and advanced equipment. Due to the rapid development and upgrading of high-tech fields, a large number of retired products have been produced. These retired electronic wastes contain a large amount of gallium and rare earth resources, which are considered to be important secondary resources of gallium and rare earth, and are more famous as urban minerals. In order to achieve the leaching of gallium and rare earth in these secondary resources, sulfuric acid leaching is a commonly used technology. During the acid leaching process, Ga and rare earth enter the sulfuric acid leaching solution, and a high concentration of Fe, as well as a small amount of Ni, Co, Cu and other elements are also leached. Therefore, how to achieve the separation and recovery of Ga, rare earth, and Fe in the leachate is of great significance for the resource utilization of electronic waste containing gallium and rare earth. Although solvent extraction is a commonly used method for metal separation and extraction in solution, which is simple to operate and easy to industrialize, the current extractant system and extraction method are difficult to apply to the extraction, separation and recovery of gallium iron rare earth in the leachate solution, which largely restricts the comprehensive recycling of gallium iron 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-mentioned problems existing in the prior art. The purpose of the present invention is to provide a method for step-by-step extraction, separation and recovery of gallium-iron-rare earth from sulfuric acid leaching solution containing gallium and rare earth electronic waste, thereby realizing the efficient separation and recovery of gallium-iron-rare earth directly from sulfuric acid leaching solution containing gallium and rare earth electronic waste by full extraction method.

[0005] The present invention proposes a method for stepwise extraction, separation and recovery of gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth, comprising the following steps: (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) The fifth organic phase is subjected to countercurrent stripping with oxalic acid 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.

[0006] Preferably, the first organic phase in step (1) is composed of the following components by volume: 10% to 20% N1923 and 80% to 90% sulfonated kerosene.

[0007] Preferably, 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.

[0008] Preferably, 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.

[0009] Preferably, the second organic phase in step (3) consists of the following components, by volume fraction: 10% to 30% TRPO and 70% to 90% sulfonated kerosene.

[0010] Preferably, the extraction phase ratio O / A of the countercurrent extraction in step (3) is 1-3:1, the number of extraction stages is 2-3, and the extraction time is 5-10 min.

[0011] Preferably, 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.

[0012] Preferably, the third organic phase in step (5) is composed of the following components by volume: 10% to 20% di(nonylphenyl) phosphate and 80% to 90% sulfonated kerosene.

[0013] Preferably, the extraction phase ratio O / A of the countercurrent extraction in step (5) is 1-2:1, the number of extraction stages is 1-2, and the extraction time is 5-10 min.

[0014] Preferably, the molar concentration of the oxalic acid solution in step (6) is 0.5-1.0 mol / L: the countercurrent stripping phase ratio A / O is 1-2:1, the stripping stage is 3-5, and the stripping time is 5-10 min.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The method provided by the present invention cleverly utilizes the performance differences between the extraction and stripping of N1923-sulfonated kerosene, TRPO-sulfonated kerosene, and di(nonylphenyl) phosphate-sulfonated kerosene mixed organic phase with gallium, iron, and rare earth elements under different acidic systems, and realizes the full extraction and separation of gallium, iron, and rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste by step-by-step extraction and stripping. The method has the advantages of simple operation, easy industrialization, and green environmental protection, and provides technical support for the comprehensive recycling of gallium- and rare earth-containing electronic waste by wet full extraction. DETAILED DESCRIPTION

[0016] The following examples are provided to further illustrate the present invention, but are not intended to limit the present invention. Unless otherwise specified, the equipment and reagents used in the present invention are conventional commercial products in the art.

[0017] Example 1 The composition of the sulfuric acid leaching solution containing gallium and rare earth electronic waste is shown in Table 1: Table 1

[0018] A method for stepwise extraction, separation and recovery of gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth comprises the following steps: (1) The first organic phase and the sulfuric acid leaching solution of gallium and rare earth electronic waste were used in a three-stage cross-current extraction with an extraction phase ratio of 2:1 and an extraction time of 10 min to obtain a primary organic phase and a primary raffinate. The extraction rates of gallium, iron and rare earth were all 100%, and the extraction rates of other ions were <5%. In terms of volume fraction, the first organic phase was composed of 10% N1923 + 90% sulfonated kerosene; (2) The primary organic phase was mixed with 6 mol / L hydrochloric acid at a stripping ratio of 1:1 (A / O) for 10 min to perform three-stage countercurrent stripping to obtain a secondary organic phase and a gallium-iron-rare earth stripping solution. The gallium-iron-rare earth stripping rates were both 100%. The secondary organic phase was washed with a clarified lime aqueous solution to a pH of 7 and then returned to step (1) for recycling as the first organic phase. (3) The second organic phase and the gallium-iron-rare earth stripping solution were used at an O / A ratio of 1:1, and the extraction time was 10 min. Three organic phases and rare earth raffinate were obtained. The gallium-iron extraction rate was 100%, and the rare earth extraction rate was only 2.07%. In terms of volume fraction, the second organic phase was composed of 30% TRPO and 70% sulfonated kerosene. (4) The three organic phases were mixed with 2 mol / L nitric acid at a stripping ratio of 3:1 and a stripping time of 10 min to perform two-stage countercurrent stripping to obtain four organic phases and gallium-iron stripping solution, with a gallium stripping rate of 98.63% and an iron stripping rate of 99.02%. The four organic phases were washed with deionized water to a pH of 7 and then returned to step (3) for recycling as the second organic phase. (5) The third organic phase and the gallium-iron stripping solution were subjected to two-stage countercurrent extraction at an extraction phase ratio of 1:1 and an extraction time of 10 min to obtain five organic phases and gallium raffinate. The iron extraction rate was 98.05% and the gallium extraction rate was only 8.01%. In terms of volume fraction, the third organic phase consisted of 10% di(nonylphenyl) phosphate and 90% sulfonated kerosene. (6) The five organic phases were mixed with 0.5 mol / L oxalic acid solution at a stripping ratio of 1:1 and a stripping time of 10 min to perform five-stage countercurrent stripping to obtain six organic phases and iron stripping solution, with an iron stripping rate of 98.45%. The six organic phases were washed with deionized water to pH = 7 and then returned to step (5) for recycling as the third organic phase.

[0019] Example 2 The composition of the sulfuric acid leaching solution containing gallium and rare earth electronic waste is shown in Table 2: Table 2

[0020] A method for stepwise extraction, separation and recovery of gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth comprises the following steps: (1) The first organic phase and the sulfuric acid leaching solution containing gallium and rare earth electronic waste were used in a first-stage cross-current extraction with an extraction phase ratio of 1:1 and an extraction time of 10 min to obtain a first organic phase and a first raffinate. The extraction rates of aluminum, iron and gallium were all 100%, and the extraction rates of other ions were <5%. In terms of volume fraction, the first organic phase was composed of 20% N1923 + 80% sulfonated kerosene; (2) The primary organic phase was mixed with 6 mol / L hydrochloric acid at a stripping ratio of 1:1 (A / O) for 5 min to perform three-stage countercurrent stripping to obtain a secondary organic phase and a gallium-iron-rare earth stripping solution, with a gallium-iron-rare earth stripping rate of 100%. The secondary organic phase was washed with a clarified lime aqueous solution to a pH of 7 and then returned to step (1) for recycling as the first organic phase. (3) The second organic phase and the gallium-iron-rare earth stripping solution were used at an O / A ratio of 1:1 and an extraction time of 10 min to perform a two-stage countercurrent extraction to obtain three organic phases and a rare earth raffinate. The gallium-iron extraction rate was 100%, and the rare earth extraction rate was only 1.73%. In terms of volume fraction, the second organic phase was composed of 30% TRPO and 70% sulfonated kerosene. (4) The three organic phases were mixed with 4 mol / L nitric acid at a stripping ratio of 3:1 and a stripping time of 5 min to perform three-stage countercurrent stripping to obtain four organic phases and gallium-iron stripping solution, with a gallium stripping rate of 99.27% ​​and an iron stripping rate of 99.46%. The four organic phases were washed with deionized water to a pH of 7 and then returned to step (3) for recycling as the second organic phase. (5) The third organic phase and the gallium-iron stripping solution were used at an O / A ratio of 1:1 and an extraction time of 10 min to perform a first-stage countercurrent extraction to obtain five organic phases and gallium raffinate. The iron extraction rate was 100%, and the gallium extraction rate was only 7.28%. In terms of volume fraction, the third organic phase was composed of 20% di(nonylphenyl) phosphate and 80% sulfonated kerosene. (6) The five organic phases were mixed with 0.5 mol / L oxalic acid solution at a stripping ratio of 2:1 and a stripping time of 10 min to perform three-stage countercurrent stripping to obtain six organic phases and iron stripping solution, with an iron stripping rate of 98.24%. The six organic phases were washed with deionized water to pH = 7 and then returned to step (5) for recycling as the third organic phase.

[0021] Example 3 The composition of the sulfuric acid leaching solution containing gallium and rare earth electronic waste is shown in Table 3: Table 3

[0022] A method for stepwise extraction, separation and recovery of gallium, iron and rare earth from sulfuric acid leaching solution of electronic waste containing gallium and rare earth comprises the following steps: (1) A first organic phase and a sulfuric acid leaching solution containing gallium and rare earth electronic waste were used for two-stage cross-current extraction at an extraction ratio of 1:1 and an extraction time of 5 min to obtain a first organic phase and a first raffinate. The extraction rates of aluminum, iron and gallium were all 100%, and the extraction rates of other ions were <5%. In terms of volume fraction, the first organic phase consisted of 15% N1923 + 85% sulfonated kerosene; (2) The primary organic phase was mixed with 5 mol / L hydrochloric acid at a stripping ratio of 3:1 (A / O) for 5 min to perform two-stage countercurrent stripping to obtain a secondary organic phase and a gallium iron rare earth stripping solution, wherein the gallium iron rare earth stripping rate was 100%. The secondary organic phase was washed with a clarified lime water solution to a pH of 7 and then returned to step (1) for recycling as the first organic phase. (3) The second organic phase and the gallium-iron-rare earth stripping solution were used at an extraction phase ratio of 3:1 and an extraction time of 5 min to perform a three-stage countercurrent extraction to obtain three organic phases and a rare earth raffinate. The gallium-iron extraction rate was 100%, and the rare earth extraction rate was only 2.33%. In terms of volume fraction, the second organic phase was composed of 30% TRPO and 70% sulfonated kerosene. (4) The three organic phases were mixed with 3 mol / L nitric acid at a stripping ratio of 1:1 and a stripping time of 5 min to perform three-stage countercurrent stripping to obtain four organic phases and gallium-iron stripping solution, with a gallium stripping rate of 98.01% and an iron stripping rate of 98.21%. The four organic phases were washed with deionized water to a pH of 7 and then returned to step (3) for recycling as the second organic phase. (5) The third organic phase and the gallium-iron stripping solution were used in a first-stage countercurrent extraction with an extraction phase ratio of 2:1 and an extraction time of 5 min to obtain five organic phases and gallium raffinate. The iron extraction rate was 99.23%, and the gallium extraction rate was only 7.73%. In terms of volume fraction, the third organic phase was composed of 15% di(nonylphenyl) phosphate and 85% sulfonated kerosene. (6) The five organic phases were mixed with 0.5 mol / L oxalic acid solution at a stripping ratio of 1:1 and a stripping time of 5 min to perform five-stage countercurrent stripping to obtain six organic phases and iron stripping solution with an iron stripping rate of 97.89%. The six organic phases were washed with deionized water to pH = 7 and then returned to step (5) for recycling as the third organic phase.

[0023] Comparative Example 1 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 instead of N1923, and the Ga and rare earth extraction rates are both less than 30%, which makes it impossible to achieve the step-by-step extraction, separation and recovery of gallium, iron and rare earth in the sulfuric acid leachate of electronic waste containing gallium and rare earth.

[0024] Comparative Example 2 This comparative example is basically the same as Example 1, except that: nitric acid is used instead of hydrochloric acid, and the primary organic phase is stripped with 6 mol / L nitric acid to obtain a gallium-iron-rare earth stripping solution; the second organic phase is extracted with the gallium-iron-rare earth stripping solution, and the Ga and iron extraction rates are both less than 15%, and the step-by-step extraction, separation and recovery of gallium-iron-rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste cannot be achieved.

[0025] Comparative Example 3 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 instead of TRPO, the iron extraction rate is only 9.02%, and the Ga extraction rate is only 68.93%, which cannot achieve the step-by-step extraction, separation and recovery of gallium, iron and rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste.

[0026] Comparative Example 4 This comparative example is basically the same as Example 2, except that sulfuric acid is used instead of nitric acid, and the three organic phases are stripped with 4 mol / L sulfuric acid to obtain gallium-iron stripping solution; the third organic phase is extracted with the gallium-iron stripping solution, and the iron extraction rate is only 63.35%, which cannot achieve the step-by-step extraction, separation and recovery of gallium-iron and rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste. Comparative Example 5

[0027] 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 instead of di(nonylphenyl) phosphate, and the iron extraction rate is only 42.73%, which cannot achieve the step-by-step extraction, separation and recovery of gallium, iron and rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste.

[0028] Comparative Example 6 This comparative example is basically the same as Example 3, except that nitric acid is used instead of oxalic acid, and the organic phase is stripped with 0.5 mol / L nitric acid solution five times. The iron extraction rate is only 11.29%, and the step-by-step extraction, separation and recovery of gallium, iron and rare earth in the sulfuric acid leaching solution of gallium- and rare earth-containing electronic waste cannot be achieved.

[0029] By comparing the embodiment and the comparative examples, it can be seen that the comparative examples cannot achieve the gallium-iron-rare earth step-by-step extraction and separation effect of the embodiment, which can illustrate that the extraction system and extraction process for step-by-step extraction and separation of gallium-iron-rare earth from the sulfuric acid leachate containing gallium and rare earth electronic waste of the present invention are not a simple combination of extractants and extraction processes or conventional replacements of the same type, but have unexpected synergistic and significant gain effects; and when the extraction method, number of stages, time, etc. are within the range required by the present invention, the extraction and separation effects of each metal can be further guaranteed.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in 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) The fifth organic phase is subjected to countercurrent stripping with oxalic acid 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.

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 first organic phase in step (1) is composed of the following components by volume: 10% to 20% N1923 and 80% to 90% sulfonated kerosene.

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 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.

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 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.

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 second organic phase in step (3) is composed of the following components by volume: 10% to 30% TRPO and 70% to 90% sulfonated kerosene.

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 (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.

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 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.

8. 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 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.

9. 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.

10. 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 countercurrent stripping ratio A / O is 1-2:1, the stripping stage is 3-5, and the stripping time is 5-10 min.

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