Method for efficiently enriching gallium and separating iron from pressurized zinc hydrometallurgy solution

Abstract

The invention relates to a method for efficiently enriching gallium and separating iron from a pressurized zinc hydrometallurgy solution, which comprises the following steps: oxidizing a zinc oxygen pressure leaching solution to oxidize Fe < 2 + > into Fe < 3 + > to obtain a first solution; adding PbO and ZnO into the first solution, and adjusting the pH value to 2.0-2.4 to obtain a second solution; adding activated carbon into the second solution, adsorbing and filtering to obtain gallium-rich precipitate; h2SO4 is added into the gallium-rich precipitate to leach out zinc, and a gallium enriched product is obtained; strong base is added into one part of the gallium enrichment for leaching, and gallium alkaline leaching liquid and iron slag are obtained; if the gallium content in the gallium alkaline leaching solution is 20-50g / L, collecting the gallium alkaline leaching solution, if the gallium content in the gallium alkaline leaching solution is lower than 20g / L, mixing the gallium alkaline leaching solution with the other part of the gallium enrichment, adding the strong base again, and circularly leaching; wherein the zinc oxygen pressure leaching solution comprises the following components: 150 to 200 g / L of Zn, 10 to 15 g / L of Fe < 2 + >, 0.1 to 0.5 g / L of Fe < 3 + >, 10 to 25 g / L of H2SO4 and 10 to 30 mg / L of Ga < 3 + >. According to the method, the enrichment degree of gallium is improved, and effective separation of gallium is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of gallium recovery and extraction, and in particular to a method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution. Background Art

[0002] Gallium is an important basic material supporting the development of modern computers, 5G communications, aerospace, new energy, and medical and health high-tech.

[0003] Gallium is distributed very dispersedly in the earth's crust, mainly associated with non-ferrous metal deposits such as zinc and aluminum. At present, 90% of the world's gallium comes from aluminum smelting and 10% of gallium comes from zinc smelting.

[0004] Traditional wet zinc smelting adopts a roasting-leaching process. During the roasting process, gallium is stored in zinc ferrite. Subsequently, the atmospheric pressure leaching process is used to store gallium in the leaching residue. When the leaching residue is volatilized in a rotary kiln, the gallium remains in the kiln slag, which is difficult to recover.

[0005] When the pressurized wet leaching process is used to directly treat zinc concentrate, more than 90% of gallium is leached into the solution. The zinc oxygen pressure leaching solution is subsequently treated with a zinc powder replacement process, and gallium is enriched in the replacement slag. However, the gallium enrichment efficiency in this process is low, at only 50%. At the same time, the gallium phase in the replacement slag is complex, and the subsequent recovery of gallium from the replacement slag has problems such as a lengthy process flow and a low recovery rate.

[0006] Because of Ga 3+ with Fe 3+ The radius is similar, and Ga 3+ with Fe 3+ The trends are relatively consistent. The core issue in the gallium enrichment process is how to efficiently precipitate gallium from the pressurized wet zinc smelting solution and quickly separate gallium from iron in the gallium enriched product. Summary of the invention

[0007] Based on this, in order to overcome the problems of low gallium enrichment efficiency and difficulty in separating gallium from iron in existing pressurized wet zinc smelting solutions, the present invention provides a method for efficiently enriching gallium and separating iron from a pressurized wet zinc smelting solution, thereby improving the enrichment of gallium and achieving effective separation of gallium.

[0008] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0009] Fe 2+ Oxidation: Oxidize the zinc oxygen pressure leaching solution to make Fe 2+ Oxidized to Fe 3+ , obtaining a first solution;

[0010] pH adjustment: adding PbO and ZnO to the first solution, adjusting the pH to 2.0-2.4, to obtain a second solution;

[0011] Adsorption precipitation: adding activated carbon to the second solution, filtering after adsorption to obtain a gallium-rich precipitate;

[0012] Dilute acid zinc leaching: adding H2SO4 to the gallium-rich precipitate to leach zinc, thereby obtaining a gallium-enriched product;

[0013] Circular leaching: adding strong alkali to a part of the gallium enriched material for leaching to obtain gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution is 20-50 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 20 g / L, it is mixed with another part of the gallium enriched material, and strong alkali is added again for circular leaching;

[0014] The zinc oxygen pressure leaching solution comprises the following components: Zn 2+ 150~200g / L,Fe 2+ 10~15g / L, Fe 3+ 0.1~0.5g / L, H2SO4 10~25g / L, Ga 3+ 10~30mg / L.

[0015] The chemical reaction equation involved in the present invention is as follows:

[0016] Fe 2+ Oxidation: Fe 2+ +O2+4H+→4Fe 3+ +2H2O

[0017] pH adjustment:

[0018] Adsorption precipitation:

[0019] Cycle leaching:

[0020] Compared with the prior art, the advantages of the present invention are: (1) without affecting the zinc extraction in the main process, the deep enrichment of gallium in the pressurized wet zinc smelting leaching solution is achieved; (2) the efficient separation of iron and gallium in the gallium enriched product is achieved; (3) the short-process extraction of gallium in the gallium enriched product is achieved; (4) the by-product iron slag has a high iron grade and can be used as a raw material for blast furnace ironmaking.

[0021] As a preferred embodiment, the Fe 2+ The oxidation method is: at 80-90℃, oxygen is introduced at a rate of 0.25-0.5L / min, and the zinc is pressure-leached to remove Fe 3+ When the concentration increases to 1-1.5 g / L, oxygen is stopped to obtain the first solution.3+ The concentration is conducive to the subsequent Fe 3+ and Ga 3+ Coprecipitation, Fe 3+ Low concentration will lead to incomplete precipitation and affect the gallium recovery rate; Fe 3+ High concentrations will result in excessive precipitation, which in turn will reduce the grade of gallium.

[0022] As a preferred solution, the amount of ZnO added is 66.7-333.3% of the PbO based on the mass of Pb and Zn. A suitable ratio of zinc oxide to lead oxide can be beneficial to the subsequent gallium enrichment. If the lead oxide is too little, the gallium precipitation is incomplete, and if the lead oxide is too much, the amount of leached slag is large, which leads to low gallium grade in the replacement slag. Zinc oxide adjusts the pH to a suitable range without affecting the gallium enrichment and zinc extraction in the main process.

[0023] As a preferred solution, the pH adjustment method is: after adding the PbO and ZnO, react at 80 to 90° C. for 0.5 to 3 hours to obtain a second solution.

[0024] As a preferred solution, the amount of activated carbon added is 0.2-0.4 g / L. If the amount of activated carbon added is too low, the precipitation efficiency will be low or even incomplete precipitation will occur, affecting the gallium recovery rate; if the amount of activated carbon added is too high, the precipitation amount will be too high, thereby reducing the gallium grade.

[0025] As a preferred solution, the adsorption precipitation method is: after adding the activated carbon, aging for 2 to 4 hours at 80 to 90° C., and then filtering to obtain a gallium-rich precipitate. Adding activated carbon to assist precipitation can effectively reduce the gallium content in the neutralized solution. In addition, the activated carbon can also adsorb free gallium ions in the solution, further improving the recovery rate of gallium; in this step, a neutralized liquid is also obtained, and the neutralized liquid can recover zinc.

[0026] As a preferred solution, the dilute acid zinc leaching method is: at 80-90°C, add 0.05-0.1 mol / L H2SO4 at a liquid-to-solid ratio of 2.5-5 mL / g, and leaching for 15-30 minutes to obtain a gallium enriched product. Using dilute sulfuric acid acid leaching can avoid gallium leaching and reduce the gallium recovery rate; in this step, a zinc leaching solution is also obtained, which can be mixed with a zinc oxygen pressure leaching solution for cyclic production.

[0027] As a preferred embodiment, the strong base includes sodium hydroxide.

[0028] As a preferred solution, the cyclic leaching method is: at 80-90°C, add 1-4 mol / L NaOH at a liquid-to-solid ratio of 2.5-5 mL / g, and leach for 1-4 hours to obtain gallium alkali leaching solution and iron slag. Using a strong alkali of appropriate concentration can leach gallium as much as possible, improve the recovery rate of gallium, and reduce the loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a process flow chart of a method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution. DETAILED DESCRIPTION

[0030] In order to further understand the present invention, the present invention is described in detail below in conjunction with the embodiments. However, it should be noted that the embodiments do not limit the scope of protection claimed for the present invention.

[0031] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0032] Fe 2+ Oxidation: oxygen is introduced into the zinc oxygen pressure leaching solution at a rate of 0.25-0.5 L / min. 3+ When the concentration increases to 1-1.5 g / L, oxygen flow is stopped to obtain a first solution.

[0033] pH adjustment: adding PbO and ZnO to the first solution, adjusting the pH to 2.0-2.4, reacting for 0.5-3h to obtain a second solution;

[0034] Adsorption precipitation: adding activated carbon to the second solution, wherein the amount of the activated carbon added is 0.2-0.4 g / L, aging for 2-4 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0035] Dilute acid zinc leaching: add 0.05-0.1 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 2.5-5 mL / g, and leaching for 15-30 min to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0036] Circular leaching: adding 1-4 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 2.5-5 mL / g, leaching for 1-4 hours, and obtaining a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution is 20-50 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 20 g / L, it is mixed with another portion of the gallium enriched material, and NaOH is added again, and cyclic leaching is carried out until the gallium content in the gallium alkali leaching solution is 20-50 g / L.

[0037] All the above steps are carried out at 80-90°C.

[0038] The zinc oxygen pressure leaching solution of the embodiment of the present invention comprises the following components: Zn 2+ 180g / L, Fe 2+ 12g / L, Fe 3+ 0.25g / L, H2SO4 20g / L, Ga 3+ 20mg / L; based on the mass of Pb and Zn, the amount of ZnO added is 175% of PbO.

[0039] Example 1

[0040] like Figure 1 As shown, a method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0041] Fe 2+ Oxidation: At 85°C, oxygen was introduced into the zinc oxygen pressure leaching solution at a rate of 0.25 L / min. 3+ The concentration was increased to 1 g / L and oxygen was stopped to obtain a first solution;

[0042] pH adjustment: PbO and ZnO were added to the first solution, the pH was adjusted to 2.2, and the reaction was carried out at 85° C. for 3 h to obtain a second solution;

[0043] Adsorption precipitation: adding activated carbon to the second solution in an amount of 0.4 g / L, aging at 85°C for 4 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0044] Dilute acid zinc leaching: add 0.05 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 5 mL / g, and leaching for 30 min at 85°C to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0045] Circular leaching: add 2 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 5 mL / g, and leach for 2 h at 85° C. to obtain a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution reaches 20 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 20 g / L, mix it with another portion of the gallium enriched material, add NaOH again, and circulate leaching until the gallium content in the gallium alkali leaching solution reaches 20 g / L, and then use a purification-electrolysis method to recover gallium.

[0046] Example 2

[0047] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0048] Fe 2+ Oxidation: At 88°C, oxygen was introduced into the zinc oxygen pressure leaching solution at a rate of 0.3 L / min. 3+ The concentration was increased to 1.25 g / L and oxygen was stopped to obtain a first solution;

[0049] pH adjustment: PbO and ZnO were added to the first solution to adjust the pH to 2.1, and the reaction was carried out at 88° C. for 2.5 h to obtain a second solution;

[0050] Adsorption precipitation: adding activated carbon to the second solution in an amount of 0.3 g / L, aging at 88°C for 3 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0051] Dilute acid zinc leaching: add 0.08 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 4 mL / g, and leaching for 30 min at 88°C to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0052] Circular leaching: add 2.5 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 4 mL / g, and leach for 2 hours at 88° C. to obtain a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution reaches 25 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 25 g / L, mix it with another portion of the gallium enriched material, add NaOH again, and circulate leaching until the gallium content in the gallium alkali leaching solution reaches 25 g / L, and then use a purification-electrolysis method to recover gallium.

[0053] Example 3

[0054] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0055] Fe 2+ Oxidation: At 90°C, oxygen was introduced into the zinc oxygen pressure leaching solution at a rate of 0.25 L / min. 3+ The concentration was increased to 1.5 g / L and oxygen was stopped to obtain a first solution;

[0056] pH adjustment: PbO and ZnO were added to the first solution, the pH was adjusted to 2.0, and the reaction was carried out at 88° C. for 2 h to obtain a second solution;

[0057] Adsorption precipitation: adding activated carbon to the second solution in an amount of 0.3 g / L, aging at 90°C for 2.5 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0058] Dilute acid zinc leaching: add 0.1 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 3 mL / g, and leach for 20 min at 90°C to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0059] Circular leaching: adding 4 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 3 mL / g, leaching for 2 h at 90° C. to obtain a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution reaches 30 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 30 g / L, it is mixed with another portion of the gallium enriched material, and NaOH is added again, and cyclic leaching is carried out until the gallium content in the gallium alkali leaching solution reaches 30 g / L, and then the gallium is recovered by a purification-electrolysis method.

[0060] Example 4

[0061] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0062] Fe 2+ Oxidation: At 80℃, oxygen was introduced into the zinc oxygen pressure leaching solution at a rate of 0.5L / min. 3+ The concentration was increased to 1.5 g / L and oxygen was stopped to obtain a first solution;

[0063] pH adjustment: PbO and ZnO were added to the first solution, the pH was adjusted to 2.4, and the reaction was carried out at 80° C. for 3 h to obtain a second solution;

[0064] Adsorption precipitation: adding activated carbon to the second solution in an amount of 0.2 g / L, aging at 80°C for 2 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0065] Dilute acid zinc leaching: add 0.1 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 2.5 mL / g, and leach for 15 min at 80°C to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0066] Circular leaching: adding 4 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 2.5 mL / g, leaching for 4 hours at 80° C. to obtain a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution reaches 40 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 40 g / L, it is mixed with another portion of the gallium enriched material, and NaOH is added again, and leaching is circulated until the gallium content in the gallium alkali leaching solution reaches 40 g / L, and then the gallium is recovered by a purification-electrolysis method.

[0067] Example 5

[0068] A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution comprises the following steps:

[0069] Fe 2+ Oxidation: At 83°C, oxygen was introduced into the zinc oxygen pressure leaching solution at a rate of 0.4 L / min. 3+ The concentration was increased to 1.3 g / L and oxygen was stopped to obtain the first solution;

[0070] pH adjustment: PbO and ZnO were added to the first solution, the pH was adjusted to 2.0, and the reaction was carried out at 83° C. for 0.5 h to obtain a second solution;

[0071] Adsorption precipitation: adding activated carbon to the second solution in an amount of 0.3 g / L, aging at 83°C for 2 hours and then filtering to obtain gallium-rich precipitate and neutralized liquid; the neutralized liquid can be used to recover zinc;

[0072] Dilute acid zinc leaching: add 0.1 mol / L H2SO4 to the gallium-rich precipitate at a liquid-solid ratio of 5 mL / g, and leaching for 15 min at 83°C to obtain a gallium-enriched product and a zinc leaching solution; the zinc leaching solution can be mixed with a zinc oxygen pressure leaching solution for cyclic production;

[0073] Circular leaching: add 2 mol / L NaOH to a portion of the gallium enriched material at a liquid-to-solid ratio of 3 mL / g, and leach for 1 hour at 83° C. to obtain a gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution reaches 50 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 50 g / L, mix it with another portion of the gallium enriched material, add NaOH again, and circulate leaching until the gallium content in the gallium alkali leaching solution reaches 50 g / L, and then use a purification-electrolysis method to recover gallium.

[0074] Comparative Example 1

[0075] No Fe 2+ The oxidation step and other steps are exactly the same as those in Example 3.

[0076] Comparative Example 2

[0077] Only zinc oxide was used in the pH adjustment step, and the other steps were exactly the same as those in Example 3.

[0078] Comparative Example 3

[0079] No activated carbon was added in the adsorption precipitation step, and the other steps were exactly the same as in Example 3.

[0080] The results of the embodiments and comparative examples are shown in Table 1. As can be seen from Table 1, by 2+ Oxidation, pH adjustment with lead oxide, and adsorption and precipitation with activated carbon can effectively achieve efficient gallium enrichment. 2+ Oxidation, Pb 2+ When activated carbon is used to assist adsorption and precipitation, the gallium concentration in the neutralized liquid increases significantly, which is not conducive to the efficient enrichment of gallium in the pressurized wet zinc smelting process.

[0081] Table 1 Examples and Comparative Examples Results

[0082] <![CDATA[Post-neutralization solution Ga 3+ Concentration (mg / L)]]> <![CDATA[Ga 3+ Recovery rate (%)]]> Iron content of iron slag (wt%) Example 1 1 95 65.8 Example 2 0.5 97.5 67.2 Example 3 0.25 98.75 68.3 Example 4 0.2 99 68.8 Example 5 0.75 96.25 67.4 Comparative Example 1 10 50 65.8 Comparative Example 2 8 60 66.2 Comparative Example 3 5 75 67.3

Claims

1. A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution, characterized in that: The following steps are involved: Fe 2+ Oxidation: Oxidize the zinc oxygen pressure leaching solution to make Fe 2+ Oxidized to Fe 3+ , obtaining a first solution; pH adjustment: adding PbO and ZnO to the first solution, adjusting the pH to 2.0-2.4, to obtain a second solution; Adsorption precipitation: adding activated carbon to the second solution, filtering after adsorption to obtain a gallium-rich precipitate; Dilute acid zinc leaching: adding H2SO4 to the gallium-rich precipitate to leach zinc, thereby obtaining a gallium-enriched product; Circular leaching: adding strong alkali to a part of the gallium enriched material for leaching to obtain gallium alkali leaching solution and iron slag; if the gallium content in the gallium alkali leaching solution is 20-50 g / L, it can be collected; if the gallium content in the gallium alkali leaching solution is lower than 20 g / L, it is mixed with another part of the gallium enriched material, and strong alkali is added again for circular leaching; The zinc oxygen pressure leaching solution comprises the following components: Zn 2+ 150~200g / L,Fe 2+ 10~15g / L, Fe 3+ 0.1~0.5g / L, H2SO4 10~25g / L, Ga 3+ 10~30mg / L.

2. A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 1, characterized in that: The Fe 2+ The oxidation method is: at 80-90℃, oxygen is introduced at a rate of 0.25-0.5L / min, and the zinc is pressure-leached to remove Fe 3+ When the concentration increases to 1-1.5 g / L, oxygen flow is stopped to obtain a first solution.

3. The method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 1, characterized in that: Calculated by the mass of Pb and Zn, the added amount of ZnO is 66.7-333.3% of the PbO.

4. A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 3, characterized in that: The pH adjustment method comprises: adding the PbO and ZnO, reacting at 80 to 90° C. for 0.5 to 3 hours to obtain a second solution.

5. The method of efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 1, characterized in that: The added amount of the activated carbon is 0.2-0.4 g / L.

6. A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 5, characterized in that The adsorption precipitation method comprises: adding the activated carbon, aging for 2 to 4 hours at 80 to 90° C., and then filtering to obtain a gallium-rich precipitate.

7. The method of efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 1, characterized in that: The dilute acid zinc leaching method comprises: adding 0.05-0.1 mol / L H2SO4 at a liquid-solid ratio of 2.5-5 mL / g at 80-90° C., leaching for 15-30 minutes, and obtaining a gallium-enriched product.

8. The method of efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 1, characterized in that: The strong base includes sodium hydroxide.

9. A method for efficiently enriching gallium and separating iron from a pressurized hydrometallurgical zinc solution according to claim 8, characterized in that: The circulating leaching method comprises: adding 1-4 mol / L NaOH at a liquid-to-solid ratio of 2.5-5 mL / g at 80-90° C., leaching for 1-4 hours, and obtaining gallium alkali leaching solution and iron slag.

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