Multistage focusing entangled fluid type large-phase-ratio coupling precise opposite spraying microreactor, tannin germanium precipitation method and application in heavy metal separation

Abstract

The invention discloses a multi-stage focusing entangled fluid type large-phase-ratio coupling precise opposite spraying microreactor, a tannin germanium precipitation method and application in heavy metal separation, and relates to the technical field of hydrometallurgy and resource recycling, an inlet A and an inlet B are arranged front and back, the inlet A is divided into an A1 microchannel outlet and an A2 microchannel outlet in the reactor, the caliber of the outlet is adjustable within 0.1-30 mm, and the inlet B is divided into an inlet A and an outlet B; preferably, the thickness is 0.3 to 1mm; an inlet B at the front part is only provided with an internal pipeline, the caliber of an outlet is adjustable in a range of 0.1-30mm, preferably 0.3-1mm, and the outlet extends downwards from the right lower part of the reactor and is intersected with A1 and A2 at a convergent point C at an included angle of 22.5 + / -22.5 degrees respectively; the A is connected with a large-volume phase injection pump, the B is connected with a small-volume phase injection pump, and the liquid phase ratio of 1: 1-50: 1 is achieved by adjusting the pump speed and the pipeline diameter. The microreactor has the advantages that the reaction efficiency is revolutionarily improved, the resource consumption is greatly reduced, the metal separation selectivity is broken through, the industrial application advantage is achieved, the environmental benefit is remarkable, and practical use is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy and resource recovery, in particular to a multi-stage focused entangled fluid large-phase-ratio coupled precise counter-jet microreactor, a tannin germanium precipitation method and application thereof in heavy metal separation. BACKGROUND

[0002] The traditional tannin germanium precipitation process has the following defects:

[0003] 1. Low reaction efficiency: stirring for 15-30 minutes under heating conditions of 60-80℃, high energy consumption and serious equipment corrosion (such as patent CN201810001234.5);

[0004] 2. Poor selectivity: tannin competes with Fe 3+ , Zn 2+ , etc. for complexation, and the germanium recovery rate is only 61.2% under 30 times the tannin dosage (literature DOI:10.1016 / j.hydromet.2020.105432);

[0005] 3. Weak adaptability: only applicable to systems with a phase ratio of <5:1, and the precipitation rate of germanium drops sharply when the phase ratio is high (>10:1) due to uneven mixing (such as patent CN202010000567.8);

[0006] 4. Excessive impurities in the post-liquid: the germanium concentration in the post-liquid after germanium precipitation is >5mg / L, which needs to be treated twice to meet the requirements of zinc electrolysis;

[0007] 5. Risk of zinc system plate burning: high germanium content in the zinc electrolysis system increases the risk of plate burning.

[0008] Existing microreactor technology (such as patent CN202110001234.5) has improved mass transfer efficiency, but still has the following problems:

[0009] Single jet structure cannot adapt to stable focusing under large phase ratio (6:1-20:1);

[0010] Lack of online pH fluctuation control capability (tannin easily gels and precipitates when pH>2.5);

[0011] Insufficient selectivity of metal separation (Zn / Ge separation ratio <10). SUMMARY

[0012] The present application aims to provide a multi-stage focused entangled fluid large-phase-ratio coupled precise counter-jet microreactor, a tannin germanium precipitation method and application thereof in heavy metal separation, to solve the problems raised in the background art.

[0013] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0014] The multi-stage focusing entangled fluid large-phase-ratio coupling precise counter-jet micro-reactor comprises the following steps:

[0015] The inlet A and the inlet B are arranged in front and back, and the inlet A is divided into two micro-channel outlets A1 and A2 in the reactor, the caliber of the outlets is adjustable in 0.1-30mm, and preferably 0.3-1mm;

[0016] The front inlet B has only one internal pipeline, the caliber of the outlet is adjustable in 0.1-30mm, and preferably 0.3-1mm, and the outlet extends downward from the front of the reactor and intersects with the A1 and A2 respectively at an angle of 22.5°±22.5° to converge at a convergence point C;

[0017] The A is connected with a large-volume-phase injection pump, and the B is connected with a small-volume-phase injection pump, and the liquid-phase ratio of 1:1-50:1 is realized by adjusting the pump speed and the pipeline diameter.

[0018] As a further scheme of the present application, the inner wall of the micro-channel is a hydrophobic modified surface, the contact angle is greater than or equal to 110°, and the material is determined according to the reaction system, including ABS resin, borosilicate glass, ceramic or PEEK.

[0019] The tannin germanium precipitation method of the multi-stage focusing entangled fluid large-phase-ratio coupling precise counter-jet micro-reactor comprises the following steps:

[0020] The precipitant phase is injected through the A1 / A2, the precipitant is a tannin solution, the treated liquid phase is injected through the B, the treated liquid is a germanium-containing solution, the A phase is connected with the treated liquid, and the B phase is connected with the tannin phase.

[0021] The flow ratio of the two phases is controlled to be 1:5-1:50, and the contact time is less than or equal to 0.1s;

[0022] The reaction temperature is maintained at 20-40℃, and external heating is not required, according to the requirements of different precipitation reactions, the micro-reactor can be heated outside, the outer layer can be wrapped with a heat exchange structure layer, or a heating and heat exchange sleeve can be added to realize the temperature control in the range of 60-120℃.

[0023] As a further scheme of the present application, the molar ratio of the precipitant to the target metal ion is 10:1-30:1, and the molar ratio of tannin to germanium is preferably greater than or equal to 15:1.

[0024] The application of the multi-stage focusing entangled fluid large-phase-ratio coupling precise counter-jet micro-reactor in heavy metal separation is suitable for selectively recovering germanium from a mixed solution containing indium, zinc and iron, and the separation factor β(Ge / In) is greater than or equal to 100, and the separation factor β(Ge / Zn) is greater than or equal to 5.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] 1. Revolutionary improvement of reaction efficiency:

[0027] Droplet size is controlled at 10-50 μm by multi-stage focusing (shear rate >5000 s -1 ) to shorten the mass transfer time to 0.01-0.1 second, 9000 times more efficient than conventional stirring (15 minutes);

[0028] The precipitation rate of germanium is stable at >95% in the pH range of 0.5-4.5 and temperature range of 20-80℃, without external heating.

[0029] 2. Resource consumption is greatly reduced:

[0030] Tannin dosage is reduced by 67% (10 times of tannin can achieve 30 times of conventional use of germanium precipitation effect);

[0031] The cost of germanium recovery is reduced to 0.1 USD / kg-Ge (conventional process 0.8 USD / kg-Ge).

[0032] 3. Metal separation selectivity breakthrough:

[0033] The separation factor of germanium / indium is 120 (conventional method <5), and the separation factor of germanium / zinc is >50;

[0034] The impurity concentration of the solution after germanium precipitation is: Ge <0.8 mg / L, In <0.05 mg / L, Zn <1.2 g / L, which meets the direct recycling standard of zinc electrolyte.

[0035] 4. Industrial application advantages:

[0036] The flux of a single micro-reactor can reach 10 L / min (parallel array design of channels), reducing the land area by 90% compared with traditional tank equipment;

[0037] Modular structure supports online pH control and flow self-adaptation, suitable for fluctuating raw materials (such as mine leachate, electronic waste acid).

[0038] 5. Significant environmental benefits:

[0039] Avoid high temperature operation, energy consumption reduced by 85% (0.2 kWh / kg-Ge vs 1.5 kWh / kg-Ge);

[0040] No organic solvent is added, and the COD value of wastewater is <50 mg / L (conventional process >2000 mg / L). BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A three-dimensional structure diagram of a multi-stage focusing entangled fluid type large-phase coupling precise counter-spraying micro-reactor.

[0042] Figure 2Figure for the effect of tannin multiple on the efficiency of the deposition of germanium for microfluidic and conventional methods.

[0043] Figure 3 Figure for the effect of tannin multiple on the efficiency of the separation of germanium and impurity ions for microfluidic methods.

[0044] Figure 4 Figure for the effect of different deposition temperatures of germanium on the efficiency of the deposition of germanium for microfluidic methods.

[0045] Figure 5 Figure for the effect of residence time on the efficiency of the deposition of germanium for microfluidic and conventional methods. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0047] Please refer to Figure 1 Multi-stage focusing entangled fluid large-phase-ratio coupling precise counter-jet microreactor, comprising:

[0048] Inlet A and inlet B are arranged in front and back, and inlet A is divided into two microchannel outlets A1 and A2 in the reactor, the caliber of the outlet is adjustable in the range of 0.1-30 mm, and preferably 0.3-1 mm;

[0049] The front inlet B has only one internal pipeline, the caliber of the outlet is adjustable in the range of 0.1-30 mm, and preferably 0.3-1 mm, and extends downward from the front of the reactor and intersects with A1 and A2 at an angle of 22.5°±22.5° at the convergence point C;

[0050] A is connected to a large-volume-phase injection pump, and B is connected to a small-volume-phase injection pump, and the liquid-phase ratio of 1:1-50:1 is realized by adjusting the pump speed and pipeline diameter.

[0051] Preferably, the inner wall of the microchannel is a hydrophobic modified surface with a contact angle of ≥110°, and the material is determined according to the reaction system, including ABS resin, borosilicate glass, ceramic or PEEK.

[0052] The tannin deposition of germanium method of the multi-stage focusing entangled fluid large-phase-ratio coupling precise counter-jet microreactor comprises the following steps:

[0053] The precipitant phase is injected through A1 / A2, the precipitant is a tannin solution, the liquid phase to be treated is injected through B, and the liquid to be treated is a germanium-containing solution, A phase communicates with the liquid to be treated, and B phase communicates with the tannin phase, small volume;

[0054] The ratio of two-phase flow is 1:5-1:50, and the contact time is less than or equal to 0.1 s.

[0055] The reaction temperature is maintained at 20-40 DEG C, and no external heating is needed.

[0056] Preferably, the molar ratio of the precipitant to the target metal ion is 10:1-30:1, and the molar ratio of tannin to germanium is preferably greater than or equal to 15:1.

[0057] The high-efficiency selective recovery method of germanium uses the microreactor of the present application, and under the conditions of pH 0.5-4.5 and tannin multiple 10-20, achieves a germanium precipitation rate of greater than or equal to 95%, while inhibiting the co-precipitation of indium, zinc and iron (the indium precipitation rate is less than or equal to 2%, the zinc is less than or equal to 20%, and the iron is less than or equal to 12%), and the germanium concentration in the liquid phase after precipitation is less than or equal to 0.8 mg / L, which can be directly used in the zinc electrodeposition process.

[0058] The multi-stage focused entangled fluid large-phase-ratio coupling precise counter-jet microreactor is suitable for selectively recovering germanium from a mixed solution containing indium, zinc and iron, and the separation factor β (Ge / In) is greater than or equal to 100, and the separation factor β (Ge / Zn) is greater than or equal to 5.

[0059] The implementation case is that for a low-germanium-content solution of 20 mg / L and a high-germanium-content solution of 350 mg / L, the low-germanium-content solution of 20 mg / L can achieve a germanium precipitation rate of more than 98% at one time with a tannin concentration of 20 times to 30 times. The high-germanium-content solution of 350 mg / L can achieve the effect of reducing the tannin amount by two-stage germanium precipitation, the first time 10 times tannin achieves a germanium precipitation rate of 80%, and the second time 30 times tannin for the germanium concentration in the remaining solution, the two-stage tannin amount is 15 times the tannin amount of the high-germanium-content solution, which achieves the effect of the maximum germanium precipitation rate and the minimum tannin amount.

[0060] Please refer to Figure 2 , phase ratio = 6:1, initial pH = 0.5, temperature = 20 DEG C.

[0061] Please refer to Figure 4 , initial pH = 0.5, phase ratio = 6:1.

[0062] Please refer to Figure 5 , initial pH = 0.5, temperature = 20 DEG C, phase ratio = 6:1.

[0063] Take a zinc smelting waste acid (Ge 120 mg / L, In 35 mg / L, Zn 58 g / L, pH 0.8) and pass it into the microreactor at a phase ratio of 10:1 with a tannin multiple of 15 times at room temperature (25 DEG C). The detection results of the solution after germanium precipitation are as follows: Ge 0.65 mg / L, In 0.03 mg / L, Zn 55.8 g / L, the germanium precipitation rate is 98.2%, and the indium loss rate is 0.09%.

[0064] The design has passed pilot-scale verification (200L / h continuous operation for 720 hours) and is the world's first industrial-scale solution for microreactor-based germanium recovery. It can be widely used in fields such as hydrometallurgy and electronic waste recycling.

[0065] Example 1: Treatment of low-concentration germanium solution

[0066] Subjects to be treated: germanium concentration 20 mg / L, pH = 1.5, containing In 50 mg / L, Zn 200 mg / L, and Fe 150 mg / L;

[0067] Conditions: Tannin ratio 15:10, contact time 0.1s, room temperature;

[0068] Results: Germanium precipitation rate was 98.2%, In 1.1%, Zn 18.3%, and Fe 9.7%.

[0069] Example 2: High-concentration germanium solution treatment

[0070] Subject to treatment: germanium concentration 350 mg / L, pH = 3.0, containing In 100 mg / L;

[0071] Conditions: Tannin concentration 20 times, ratio 1:15, contact time 0.08s;

[0072] Results: Germanium precipitation rate was 99.5%, residual germanium concentration was 0.7 mg / L, and In precipitation rate was 0.9%.

[0073] Example 3: Tannin Optimization

[0074] Comparison group: Tannin ratio 10 times (microreactor) vs 30 times (conventional stirring);

[0075] Results: The germanium precipitation rate of the microreactor was 95.6% vs. 61.2% of the conventional reactor, and the impurity precipitation rates were comparable.

[0076] Example 4: Temperature Tolerance Verification

[0077] Conditions: Germanium solution temperature 20℃ vs 80℃, tannin ratio 15 times, ratio 1:10;

[0078] Results: The precipitation rate was 98.1% at 20℃ vs. 96.3% at 80℃, proving that heating was not required.

[0079] Example 5: Co-production of industrial wastewater

[0080] The treatment of zinc electrowinning waste liquid (Ge 45mg / L, Zn 12g / L) showed a tannin ratio of 18 times, with a comparison ratio of 1:12.

[0081] Results: Germanium precipitation rate was 97.8%, residual germanium was 0.9 mg / L, and zinc loss rate was 0.02%.

[0082] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0083] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-stage focused entangled fluid-type large-scale phase-coupled precision jet microreactor, characterized in that, include: Inlet A and inlet B are arranged one after the other. Inlet A is divided into two microchannel outlets, A1 and A2, inside the reactor. The outlet diameter is adjustable from 0.1 to 30 mm, preferably 0.3 to 1 mm. The front inlet B has only one internal pipe, and the outlet diameter is adjustable from 0.1 to 30 mm, preferably 0.3 to 1 mm. It extends downward from directly below the reactor and intersects with A1 and A2 at an angle of 22.5° ± 22.5° at the convergence point C. A is connected to a large volumetric phase injection pump, and B is connected to a small volumetric phase injection pump. By adjusting the pump speed and the pipe diameter, a liquid ratio of 1:1 to 50:1 can be achieved.

2. The multi-stage focused entangled fluid-type large-scale coupled precision jet microreactor according to claim 1, characterized in that, The inner wall of the microchannel is a hydrophobically modified surface with a contact angle ≥110°. The material depends on the reaction system and includes ABS-like resin, borosilicate glass, ceramic or PEEK.

3. A method for tannin-germanium precipitation based on a multi-stage focused entangled fluid-type large-scale coupled precise spray microreactor as described in any one of claims 1-2, characterized in that, Includes the following steps: The precipitant phase is injected through A1 / A2. The precipitant is a tannin solution. The liquid phase to be treated is injected through B. The liquid to be treated is a germanium-containing solution. Phase A is connected to the liquid to be treated and has a large volume, while phase B is connected to the tannin phase and has a small volume. The two-phase flow ratio is controlled at 1:5-1:50, and the contact time is ≤0.1s; The reaction temperature is maintained at 20-40℃ without external heating. Depending on the requirements of different precipitation reactions, the outside of the microreactor can be heated by adding a heat exchange structure coating layer to the outer layer, or by adding a heating heat exchange jacket. The temperature is controlled at 60-120℃ depending on the reaction.

4. The method for tannin-germanium precipitation in a multi-stage focused entangled fluid-type large-scale coupled precise spray microreactor according to claim 3, characterized in that, The molar ratio of the precipitant to the target metal ion is 10:1-30:1, with a preferred molar ratio of tannin to germanium of ≥15:

1.

5. An application of a multi-stage focused entangled fluid-type large-scale coupled precise jet microreactor as described in claims 1-2 in the separation of heavy metals, characterized in that, It is suitable for the selective recovery of germanium from mixed solutions containing indium, zinc and iron, with separation factors β(Ge / In)≥100 and β(Ge / Zn)≥5.

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