Gallium and germanium co-extraction system and application thereof

Abstract

The invention discloses a gallium and germanium co-extraction system and application thereof, and relates to the technical field of extraction. The gallium and germanium co-extraction system comprises oxalic acid and an organic extraction agent, the organic extraction agent comprises a tertiary amine extraction agent and / or an organophosphate extraction agent. According to the gallium and germanium co-extraction system, co-extraction of gallium and germanium can be effectively achieved in the feed liquid containing gallium and germanium through matching of oxalic acid and the specific organic extraction agent, meanwhile, the extraction rate of gallium and germanium is increased, high consumption is not needed, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of extraction, and particularly relates to a gallium-germanium co-extraction system and its application. Background Art

[0002] In the existing zinc smelting system, gallium-germanium replacement slag generally undergoes two-stage oxygen-enriched leaching and one-stage atmospheric pressure leaching to obtain a sulfuric acid solution containing gallium and germanium. Usually, P204-YW100 extraction is used to recover gallium and germanium, and copper products are obtained after extraction and electrowinning of the extraction solution. However, for the extractant YW100 in the comprehensive recovery process of gallium and germanium, it has high water solubility, high unit consumption, and high production cost, and both the extraction effect and the extraction cost need to be further optimized. Summary of the Invention

[0003] The present invention aims to at least solve the above technical problems existing in the prior art. For this reason, the object of the present invention is to provide a gallium-germanium co-extraction system, which realizes the efficient co-extraction of gallium and germanium through the compounding of oxalic acid and a tertiary amine extractant or an organophosphoric acid ester extractant. Moreover, the consumption of this co-extraction system is low, which is beneficial to reducing the production cost.

[0004] The second aspect of the present invention lies in providing a method for co-extracting gallium and germanium.

[0005] The third aspect of the present invention lies in providing an application of the gallium-germanium co-extraction system or the method for co-extracting gallium and germanium.

[0006] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0007] The first aspect of the present invention provides a gallium-germanium co-extraction system, which includes oxalic acid and an organic extractant; the organic extractant includes a tertiary amine extractant and / or an organophosphoric acid ester extractant.

[0008] The gallium-germanium co-extraction system of the present invention synergistically co-extracts gallium and germanium in the gallium-germanium-containing feed liquid through the combination of oxalic acid and the organic extractant. Relying solely on conventional extractants such as P204 and P507, there is no obvious co-extraction effect on gallium and germanium. However, in the co-extraction system formed by the combination of oxalic acid and a tertiary amine extractant and / or an organophosphoric acid ester extractant in the present invention, oxalic acid can coordinate with gallium and germanium ions, enhancing the co-extraction ability of the organic extractant for gallium and germanium, thereby simultaneously improving the extraction rates of gallium and germanium and realizing the efficient co-extraction of gallium and germanium. In addition, the raw material cost of the gallium-germanium co-extraction system used in the present invention is relatively low, and the consumption during co-extraction is also low, which is beneficial to reducing the production cost.

[0009] Preferably, the concentration of oxalic acid in the system is 6-12 g / L.

[0010] More preferably, the concentration of oxalic acid in the system is 8-12 g / L.

[0011] Preferably, the tertiary amine extractant includes trioctyldecyl tertiary amine; for example, N235.

[0012] Preferably, in the system, the volume concentration of the tertiary amine extractant is 15-25%.

[0013] Preferably, the organophosphoric acid ester extractant includes tributyl phosphate (TBP).

[0014] Preferably, in the system, the volume concentration of the organophosphoric acid ester extractant is 0-20%.

[0015] More preferably, the volume concentration of the organophosphoric acid ester extractant is 0-15%.

[0016] Preferably, the acidity in the system is 1-2 mol / L.

[0017] More preferably, the acidity in the system is 1.4-1.6 mol / L.

[0018] Preferably, the acidity of the system is adjusted by adding NaOH.

[0019] More preferably, the concentration of the NaOH is 8-12 mol / L.

[0020] More preferably, the NaOH is added to the feed liquid to be extracted for acidity adjustment.

[0021] Preferably, white oil is further included in the system; the volume ratio of the white oil to the organic extractant is (1-9):1.

[0022] More preferably, the volume ratio of the white oil to the organic extractant is (2-3):1.

[0023] Even more preferably, the volume ratio of the tertiary amine extractant, the organophosphoric acid ester extractant to the white oil is (5-30):(5-20):(60-90); even more preferably (1-2):1:(7-9).

[0024] Preferably, the gallium-germanium co-extraction system is used for recovering gallium and germanium from the gallium-germanium-containing feed liquid in the zinc smelting system.

[0025] The second aspect of the present invention provides a method for co-extracting gallium and germanium, which uses the gallium-germanium co-extraction system described in the first aspect of the present invention for co-extraction.

[0026] Preferably, the method includes the following steps: preparing an organic phase containing an organic extractant, mixing it with the gallium-germanium-containing feed liquid to be extracted, adding an oxalic acid solution, and extracting to obtain an organic phase containing gallium and germanium.

[0027] Further preferably, in the co-extraction process, the volume ratio of the organic phase to the gallium- and germanium-containing feed liquid (i.e., the phase ratio O / A) is (0.8 - 1.2):1.

[0028] Further preferably, the gallium- and germanium-containing feed liquid to be extracted is the gallium- and germanium-containing feed liquid in the zinc smelting system.

[0029] Further preferably, the extraction time is 5 - 20 min.

[0030] More preferably, the extraction time is 5 - 15 min.

[0031] Still more preferably, the extraction time is 8 - 12 min.

[0032] Further preferably, the gallium- and germanium-containing organic phase obtained by extraction is stripped successively with H2SO4 solution and NaOH solution.

[0033] More preferably, the concentration of the H2SO4 solution is 2 - 3 mol / L.

[0034] More preferably, the concentration of the NaOH solution is 4 - 6 mol / L.

[0035] More preferably, water washing is carried out before stripping with H2SO4 solution and NaOH solution.

[0036] The third aspect of the present invention provides an application of the gallium-germanium co-extraction system described in the first aspect of the present invention or the method described in the second aspect of the present invention in the recovery of gallium and germanium in the zinc smelting system.

[0037] Preferably, the gallium-germanium co-extraction system or the method is used for the co-extraction of gallium and germanium from the gallium- and germanium-containing feed liquid in the zinc smelting system.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) The gallium-germanium co-extraction system of the present invention can effectively co-extract gallium and germanium from the gallium- and germanium-containing feed liquid through the combination of oxalic acid and a specific organic extractant, while improving the extraction rates of gallium and germanium, and without high consumption, which is beneficial to reducing production costs.

[0040] (2) By further adjusting conditions such as the concentration of the oxalic acid solution and the concentration of the organic extractant, the present invention can further improve the extraction effect of gallium and germanium, ensuring that the extraction rates of gallium and germanium are not less than 60%.

[0041] (3) The method for co-extracting gallium and germanium of the present invention uses the gallium-germanium co-extraction system of the present invention for extraction, which has excellent co-extraction effect on gallium and germanium, high extraction rate, and can further achieve the stepwise stripping of gallium and germanium through sulfuric acid solution and sodium hydroxide solution, and is applicable to the recovery of gallium and germanium in the zinc smelting system. Detailed Embodiments

[0042] The content of the present invention will be further described in detail below through specific examples. The raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial channels or by existing technical methods without special instructions. Unless otherwise specified, the test or measurement methods are conventional methods in the art.

[0043] N235, TBP, white oil, oxalic acid, sulfuric acid and sodium hydroxide used in the following examples and comparative examples were all purchased from the conventional market.

[0044] The gallium-germanium-containing feed liquid used in the following examples and comparative examples was the gallium-germanium-containing sulfuric acid feed liquid in the traditional zinc smelting system.

[0045] Examples 1-6

[0046] Examples 1-6 provide a gallium-germanium co-extraction system containing oxalic acid, N235, TBP and white oil. The volume concentration of TBP in the system is 10%, the oxalic acid concentration is 10 g / L, and the volume ratio of N235, TBP to white oil is 15:10:80; the acidity of the feed liquid to be extracted is titrated to 1.495 mol / L with 10 mol / L NaOH solution; the volume concentration of N235 in the system is shown in Table 1.

[0047] The gallium-germanium co-extraction of the gallium-germanium-containing feed liquid was carried out using the gallium-germanium co-extraction systems of Examples 1-6. The specific steps are as follows:

[0048] Prepare the extraction organic phase: Prepare a mixed organic phase of N235, TBP and white oil according to the volume ratio;

[0049] Prepare the feed liquid: Take the gallium-germanium-containing feed liquid and add 10 mol / L NaOH solution to adjust the acidity;

[0050] Extraction reaction: Mix the prepared mixed organic phase and the gallium-germanium-containing feed liquid with adjusted acidity evenly according to the volume ratio of 1:1 (i.e., O / A = 1:1), pour it into a separating funnel, then add oxalic acid solution and mix well, shake and extract for 10 min, and the extraction temperature is room temperature to obtain the gallium-germanium-loaded organic phase and the raffinate.

[0051] The content of each element in the gallium-germanium-containing feed liquid (i.e., the feed liquid) and the raffinate was obtained by ICP test, and the extraction rate was calculated. The extraction results are shown in Table 2.

[0052] Table 1 Volume Concentration of N235 in the Systems of Examples 1 - 6

[0053]

[0054]

[0055] Table 2 Extraction Effects of Gallium - Germanium Co - extraction Systems with Different Volume Concentrations of N235 in Examples 1 - 6

[0056]

[0057] It should be noted that the concentration unit of In in Table 2 is different from others, and the concentration unit of In is mg / L.

[0058] As shown in Table 2 above, it can be seen that with the increase of the N235 concentration, the extraction rate of Ga increases significantly, while the extraction rate of Ge gradually decreases, and the extraction rates of Fe and As also show an upward trend. In addition, N235 has no obvious influence on the extraction effects of Cu, Zn, Cd, In, and Co.

[0059] Examples 7 - 11

[0060] Examples 7 - 11 provide a gallium - germanium co - extraction system containing oxalic acid, N235, TBP, and white oil. The volume concentration of N235 in the system is 20%, the concentration of oxalic acid is 10 g / L, and the volume ratio of N235, TBP, and white oil is 15:10:80; the acidity of the feed liquid to be extracted is titrated to 1.495 mol / L with 10 mol / L NaOH solution; the volume concentration of TBP in the system is shown in Table 3.

[0061] The gallium - germanium co - extraction of the feed liquid containing gallium and germanium is carried out using the gallium - germanium co - extraction system of Examples 7 - 11, and the specific steps are the same as those in Example 1; the element contents in the feed liquid containing gallium and germanium (i.e., the feed liquid) and the raffinate are obtained by ICP testing, and the extraction rate is calculated. The extraction results are shown in Table 4.

[0062] Table 3 Volume Concentration of TBP in the Systems of Examples 7 - 11

[0063] Example 7 Example 8 Example 9 Example 10 Example 11 Volume concentration of TBP 0％ 5％ 10％ 15％ 20％

[0064] Table 4 Extraction Effects of Gallium - Germanium Co - extraction Systems with Different Volume Concentrations of TBP in Examples 7 - 11

[0065]

[0066] It should be noted that the concentration unit of In in Table 4 is different from others, and the concentration unit of In is mg / L.

[0067] As can be seen from Table 4, with the increase in the TBP concentration, the extraction rate of Ga decreases, while the extraction rate of Ge increases. However, the change in the TBP concentration has no significant effect on the extraction of other elements. Nevertheless, with the increase in the TBP concentration, the phase separation time continuously prolongs. The phase separation time is 60 s at 0%, 161 s at 5%, and has reached 453 s at 10%. The organic phase gradually becomes turbid. Therefore, controlling the TBP concentration is beneficial to adjusting the co-extraction rate of gallium and germanium and shortening the phase separation time.

[0068] Examples 12 - 16

[0069] Examples 12 - 16 provide a co-extraction system for gallium and germanium, containing oxalic acid, N235, TBP, and white oil. In the system, the volume concentration of N235 is 20%, the volume concentration of TBP is 10%, the concentration of oxalic acid is 10 g / L, and the volume ratio of N235, TBP, and white oil is 15:10:80; the acidity of the feed solution to be extracted is adjusted by titration with 10 mol / L NaOH solution. The specific acidity of each example is shown in Table 5.

[0070] The co-extraction of gallium and germanium from the feed solution containing gallium and germanium is carried out using the co-extraction system of Examples 12 - 16. The specific steps are the same as those in Example 1; the content of each element in the feed solution containing gallium and germanium (i.e., the feed solution) and the raffinate is obtained by ICP test, and the extraction rate is calculated. The extraction results are shown in Table 6.

[0071] Table 5 Acidity in the systems of Examples 12 - 16

[0072] Example 12 Example 13 Example 14 Example 15 Example 16 Acidity (mol / L) 2.42 1.89 1.43 1 0.55

[0073] Table 6 Co-extraction effect of gallium and germanium in the systems with different acidities in Examples 12 - 16

[0074]

[0075] It should be noted that in Table 6, the concentration units of In in the feed solution and the extract are mg / L, which are different from those of other elements.

[0076] As shown in Table 6, low acidity is beneficial to the extraction of Ga, while high acidity is beneficial to the extraction of Ge. High-efficiency co-extraction of gallium and germanium can be achieved by controlling the appropriate acidity. In addition, it can be preliminarily judged that there is no co-extraction phenomenon for In and Cd.

[0077] Examples 17 - 23

[0078] Examples 17 to 23 provide a gallium-germanium co-extraction system containing oxalic acid, N235 and white oil. The volume concentration of N235 in the system is 20%, the TBP content is 0; the volume ratio of N235 to white oil is 35:80; 10 mol / L NaOH solution is used to titrate and adjust the acidity of the feed solution to be extracted to 1.495 mol / L; the oxalic acid concentration in the system is shown in Table 7.

[0079] The gallium-germanium co-extraction of the gallium-germanium-containing feed solution is carried out using the gallium-germanium co-extraction system of Examples 17 to 23. The specific steps are the same as those in Example 1; the content of each element in the gallium-germanium-containing feed solution (i.e., the feed solution) and the raffinate is obtained by ICP testing, and the extraction rate is calculated. The extraction results are shown in Table 8.

[0080] Table 7 Oxalic acid concentration in the systems of Examples 17 to 23

[0081]

[0082] Table 8 Extraction effects of the gallium-germanium co-extraction systems with different oxalic acid concentrations in Examples 17 to 23

[0083]

[0084]

[0085] From the results in Table 8, it can be seen that as the oxalic acid concentration increases, the extraction rates of Ga and Ge both gradually increase, and the extraction rates of As, Zn, etc. decrease, but at the same time, the extraction rate of Fe also shows an upward trend. However, too high a concentration of oxalic acid will not only increase the cost but also cause the precipitation of copper and zinc oxalates.

[0086] Example 24

[0087] Example 24 performs stripping on the organic phase loaded with gallium and germanium obtained in Example 9 (TBP volume concentration is 10%). The specific steps are as follows:

[0088] First, wash the organic phase loaded with gallium and germanium with deionized water to remove impurity elements such as arsenic; then add 2.5 mol / L sulfuric acid solution for the stripping of gallium. The stripping phase ratio O / A = 1:1, and the stripping time is 10 min to obtain a sulfuric acid solution containing gallium and an organic phase loaded with germanium; add 5 mol / L sodium hydroxide solution for the stripping of germanium. The stripping phase ratio O / A = 1:1, and the stripping time is 10 min to obtain a sodium hydroxide solution containing germanium; the stripping separation of gallium and germanium is completed.

[0089] Among them, Example 24 corresponds to Example 8, Example 15 corresponds to Example 9, and so on.

[0090] The stripping rate is calculated after each step of washing / stripping, and the stripping effects of each step in Example 24 are obtained, as shown in Table 9:

[0091] Table 9 Stripping effect of gallium- and germanium-containing organic phase obtained by co-extraction in Example 24

[0092] As Ga Ge Stripping rate / % 77.43 92.12 79.63

[0093] In this example, it can be found from the results in Table 9 that most of the arsenic can be removed by water washing first, and then sulfuric acid is used for the stripping of gallium, with the stripping rate reaching over 92%. At this time, the stripping rate of germanium is only 1.02%. Then, sodium hydroxide is used for the stripping of germanium, and the stripping rate of germanium reaches 79.63%, thus realizing the stepwise stripping of gallium and germanium.

[0094] Comparative Example 1

[0095] The difference between Comparative Example 1 and Example 4 is that in the gallium-germanium co-extraction system, 8 g / L of citric acid is used to replace 10 g / L of oxalic acid, and the rest is the same as in Example 4; the co-extraction steps are also the same as in Example 4.

[0096] The extraction rate of this comparative example was calculated by the same method as in Example 4 and is shown in Table 10.

[0097] Table 10 Extraction rate of gallium-germanium co-extraction system in Comparative Example 1

[0098] Ga Ge Extraction rate / % 2.99 70.97

[0099] It can be seen from Table 10 that although the replacement of oxalic acid with citric acid has a certain improvement in the extraction rate of germanium by the N235-TBP system, it has no obvious effect on the extraction of gallium, and the extraction rate is only 2.99%, so the co-extraction of gallium and germanium cannot be achieved.

[0100] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A gallium-germanium co-extraction system, characterized in that, It includes oxalic acid and an organic extractant; the organic extractant includes a tertiary amine extractant and / or an organic phosphate ester extractant.

2. The gallium-germanium coextraction system according to claim 1, wherein The concentration of oxalic acid in the system is 6 - 12 g / L.

3. The gallium-germanium co-extraction system according to claim 1, wherein The tertiary amine extractant includes trioctyldecylamine; And / or, in the system, the volume concentration of the tertiary amine extractant is 15 - 25%.

4. The gallium-germanium co-extraction system according to claim 1, wherein The organic phosphate ester extractant includes tributyl phosphate; And / or, in the system, the volume concentration of the organic phosphate ester extractant is 0 - 20%.

5. The gallium-germanium co-extraction system according to any one of claims 1 to 4, characterized in that, The acidity of the system is 1 - 2 mol / L; And / or, the acidity of the system is adjusted by adding NaOH.

6. The gallium-germanium co-extraction system according to any one of claims 1 to 4, characterized in that, The system also includes white oil; the volume ratio of the white oil to the organic extractant is (1 - 9):

1.

7. A method for co-extracting gallium and germanium, characterized in that, Co - extraction is carried out using the gallium - germanium co - extraction system according to any one of claims 1 - 6.

8. The method according to claim 7, wherein It includes the following steps: Prepare an organic phase containing an organic extractant, mix it with the gallium - germanium - containing feed liquid to be extracted, add an oxalic acid solution, and extract to obtain a gallium - germanium - containing organic phase.

9. The method according to claim 8, wherein The extraction time is 5 - 20 min; And / or, the gallium - germanium - containing organic phase obtained by extraction is stripped successively with an H2SO4 solution and an NaOH solution.

10. An application of the gallium - germanium co - extraction system according to any one of claims 1 - 6 or the method according to any one of claims 7 - 9 in the recovery of gallium and germanium in a zinc smelting system.

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