Large-scale microreactor coupled in vitro focused wide-range germanium recovery method and equipment

Abstract

The present application relates to the technical field of hydrometallurgy solid waste resource utilization, and discloses a wide-range germanium recovery method coupled with a micro-reactor and an external focusing device, the device comprising a 3D-printed corrosion-resistant micro-reactor body, a coaxial three-channel external focusing nozzle and a multi-stage parallel modular structure, the material of the 3D-printed corrosion-resistant micro-reactor body being Hastelloy C276, PEEK resin and silicon carbide ceramic, and the channel size being 0.3-3 mm; the coaxial three-channel external focusing nozzle comprising a central pipe, a middle layer annular gap and an outer layer annular gap, the central pipe being used for passing in a germanium-containing waste liquid, and the middle layer annular gap being used for passing in a tannin liquid.In the present application, the corrosion-resistant micro-reactor body is manufactured by using a multi-material 3D printing technology, thereby improving the problem that the traditional tannin germanium precipitation reactor mostly adopts glass, silicon-based materials or ordinary stainless steel, thereby causing short equipment service life, high maintenance cost and the risk of heavy metal leakage.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology in hydrometallurgy, and in particular to a wide-area germanium recovery method and equipment using a large-scale microreactor coupled with external focusing. Background Technology

[0002] Germanium, element 32 of the periodic table, with the symbol Ge, is a grayish-white metallic element with a metallic luster. It is a typical semiconductor with a melting point of approximately 937.4℃ and a boiling point of approximately 2830℃. Its crystal structure is diamond-type. It is chemically stable, does not react with air or water at room temperature, but reacts with oxygen to form germanium dioxide when heated. It can react with concentrated hydrochloric acid and concentrated sulfuric acid. As an important semiconductor material, it was widely used in electronic components such as transistors and diodes in the past, and is still used in fiber optic communications as a dopant to improve transmission performance. Because it is transparent to infrared light, it is often used in lenses and windows of infrared optical instruments. Furthermore, it has important applications in solar cells, catalysts, and medicine, making it an indispensable material in modern high-tech fields.

[0003] Traditional tannin-germanium precipitation reactors mostly use glass, silicon-based materials, or ordinary stainless steel. Because these materials are prone to corrosion in strongly acidic environments with pH < 1, they result in short equipment life, high maintenance costs, and the risk of heavy metal leakage. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides a wide-area germanium recovery method and equipment using a large-scale microreactor coupled with in vitro focusing. This method aims to improve upon the problems of traditional tannin-precipitated germanium reactors, which mostly use glass, silicon-based materials, or ordinary stainless steel. These materials are prone to corrosion in strongly acidic environments with pH < 1, resulting in short equipment lifespan, high maintenance costs, and the risk of heavy metal leakage.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a wide-area germanium recovery equipment with a large-scale microreactor coupled with external focusing, comprising a 3D-printed corrosion-resistant microreactor body, a coaxial three-channel external focusing nozzle, and a multi-stage parallel modular structure. The 3D-printed corrosion-resistant microreactor body is made of Hastelloy C276, PEEK resin, and silicon carbide ceramic, with a channel size of 0.3-3 mm. The coaxial three-channel external focusing nozzle includes a central tube, a middle annular gap, and an outer annular gap. The central tube is used to introduce germanium-containing waste liquid, the middle annular gap is used to introduce tannin liquid, and the outer annular gap is used to introduce gas sheath flow. The 3D-printed corrosion-resistant microreactor body and the coaxial three-channel external focusing nozzle can form independent functional units, each with a throughput ≥ 50 L / h. Multiple independent functional units can form a multi-stage parallel modular structure.

[0006] By adopting the above technical solution, a corrosion-resistant microreactor body composed of Hastelloy C276, PEEK resin, modified ABS resin, and silicon carbide ceramic is manufactured using multi-material 3D printing technology. This enables the reactor to operate stably in a strong acid environment, thereby improving the problems of traditional tannin-germanium precipitation reactors, which mostly use glass, silicon-based materials, or ordinary stainless steel. These materials are prone to corrosion in strong acid environments with pH < 1, resulting in short equipment life, high maintenance costs, and the risk of heavy metal leakage.

[0007] Preferably, the pressure of the gas sheath flow is 0.1-0.6 MPa, and the droplet diameter of the gas sheath flow is 30-80 μm; the diameter of the central tube is 0.5-1.2 mm, and the flow velocity of the germanium-containing waste liquid in the central tube is 3-12 m / s; the width of the middle annular gap is 0.1-0.3 mm, and the flow velocity of the tannin liquid in the middle annular gap is 3-5 m / s; the width of the outer annular gap is 0.2-0.5 mm, and the flow velocity of the gas sheath flow in the outer annular gap is 5-10 m / s; the flow velocity ratio of the germanium-containing waste liquid to the tannin liquid is 1:6-1:10.

[0008] Preferably, the 3D-printed corrosion-resistant microreactor body is manufactured using selective laser melting technology or DLP photopolymerization sintering process. The surface roughness Ra of the 3D-printed corrosion-resistant microreactor body is ≤0.8μm, and the pressure resistance rating is >2MPa. The inlet section of the channel of the 3D-printed corrosion-resistant microreactor is provided with a tapered flow guiding structure, the contraction angle of which is 15-30°. The outlet section of the channel of the 3D-printed corrosion-resistant microreactor is provided with a diffuser section, the diffusion angle of which is 10-20°.

[0009] Preferably, the system also includes an online monitoring system, which comprises a germanium ion selective electrode and a flow controller. The germanium ion selective electrode is used to detect the concentration of germanium ions in the germanium-containing waste liquid in real time, and the detection limit of the germanium ion selective electrode is 0.1 ppm. The flow controller is used to regulate the injection rate of the tannin solution in real time. The inner wall of the channel of the 3D printed corrosion-resistant microreactor body is provided with a spiral turbulence structure, and the turbulence Reynolds number Re of the spiral turbulence structure is greater than 3000.

[0010] A wide-area germanium recovery method using a large-scale microreactor coupled with in vitro focusing includes the following steps:

[0011] Germanium-containing waste liquid is introduced into the central tube of a coaxial three-channel external focusing nozzle at a flow rate of 3-12 m / s;

[0012] The tannin solution is introduced into the middle annular gap of the coaxial three-channel external focusing nozzle at a flow rate of 3-5 m / s, and the amount of tannin solution used is 5-20 times the molar amount of germanium.

[0013] The gas sheath flow is introduced into the outer annular gap of the coaxial three-channel external focusing nozzle at a flow rate of 5-10 m / s to form droplets of 30-80 μm.

[0014] The reaction is carried out under conditions of pH 0.5-1.5 and temperature 20-40℃, with a reaction residence time of <10 seconds, resulting in the formation of a precipitate;

[0015] The precipitate formed by the reaction is collected and then calcined at a low temperature of 300-400℃.

[0016] Preferably, the volume ratio of the germanium-containing liquid phase in the germanium-containing waste liquid to the tannin phase in the tannin solution is 20:1-5:1; the germanium-containing waste liquid includes one or more of the following: zinc smelting germanium precipitation solution, zinc smelting indium extraction solution, steel plant dust germanium-containing solution, fly ash alkaline leaching solution, copper dust acid leaching solution, and lead-zinc slag pickling solution.

[0017] Preferably, when treating zinc smelting leaching solution, the germanium concentration in the germanium-containing waste liquid is 10-50 ppm, and the tannin solution is controlled to be 10-15 times in excess; when treating steel plant flue dust pickling solution, the germanium concentration in the germanium-containing waste liquid is 30-200 ppm, and the tannin solution is controlled to be 15-20 times in excess; the gas sheath flow is one or more of nitrogen and inert gas.

[0018] The application of a large-scale, microreactor-coupled, extracorporeal focusing wide-area germanium recovery equipment is applied to the wide-area germanium recovery of zinc smelting germanium-containing solutions, zinc smelting indium-extraction solutions, steel plant flue dust containing germanium, fly ash alkaline leaching solutions, copper flue dust acid leaching solutions, and lead-zinc slag pickling solutions.

[0019] The present invention has the following beneficial effects:

[0020] 1. In this invention, a corrosion-resistant microreactor body composed of Hastelloy C276, PEEK resin, and silicon carbide ceramic is manufactured by using multi-material 3D printing technology, thereby enabling the reactor to operate stably in a strong acid environment. This improves upon the traditional tannin-germanium precipitation reactors, which mostly use glass, silicon-based materials, or ordinary stainless steel. These materials are prone to corrosion in strong acid environments with pH < 1, resulting in short equipment life, high maintenance costs, and the risk of heavy metal leakage.

[0021] 2. In this invention, a coaxial three-channel external focusing nozzle is designed to achieve enhanced gas-liquid focusing mass transfer, compressing the droplet diameter to 50μm and combining it with high-shear turbulence, thereby reducing the amount of tannin used and eliminating the need for pH adjustment and heating. This improves upon the traditional tannin-germanium precipitation technology, which often requires an excess of 25-35 times tannin, pH adjustment, and heating to 40-80℃. Due to the excessive tannin consumption and additional operating conditions, the technology suffers from high tannin consumption, high energy consumption, and complex operation.

[0022] 3. In this invention, high-shear turbulence (flow velocity 5-12 m / s) is used to suppress the competitive complexation of impurities such as Fe³+, Fe²+, and Zn²+, thereby reducing the impurity entrainment rate. This improves the problem in the traditional tannin-germanium precipitation process where impurity ions easily form stable complexes with tannins. Due to the low efficiency of impurity competitive complexation and reaction contact, the germanium selectivity is low, the impurity entrainment rate is high, and the germanium precipitation rate is only 80-90%.

[0023] 4. In this invention, by adopting a modular parallel microreactor design, the single-channel throughput reaches 50L / h and the system processing capacity is >3m³ / h, thereby improving the equipment's processing capacity. This improves the problem that most traditional microchannel reactors have a single-channel throughput of less than 10L / h and are prone to clogging. Due to insufficient processing capacity, they are difficult to match the daily processing needs of hundreds of tons of metallurgical waste liquid and experience efficiency degradation after industrial scale-up.

[0024] 5. In this invention, through the comprehensive application of the above technologies, energy consumption and wastewater discharge are reduced, thereby improving the problems of high energy consumption and large wastewater discharge in traditional tannin precipitation germanium and ultrasonic strengthening processes. Due to high energy consumption and large wastewater discharge, the overall cost is high and the environmental impact is significant. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the wide-area germanium recovery equipment that couples a large-scale microreactor with in vitro focusing, as proposed in this invention.

[0026] Figure 2 This is a schematic diagram illustrating the steps of the wide-area germanium recovery method proposed in this invention, which involves coupling a large-scale microreactor with in vitro focusing. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] See attached document Figure 1 This invention provides a wide-area germanium recovery equipment that couples a large-scale microreactor with external focusing. Germanium waste liquid is transported from a germanium storage tank to the central tube of a coaxial three-channel external focusing nozzle via a pump. Tannin liquid is transported from a tannin liquid storage tank to the middle annular gap of the coaxial three-channel external focusing nozzle via a pump. Gas sheath flow is transported to the outer annular gap of the coaxial three-channel external focusing nozzle via a pump. Then, it is transported to the interior of a 3D-printed corrosion-resistant microreactor body. After passing through a converging chute, it is then filtered by plate and frame filter press to finally obtain germanium-precipitated liquid and germanium slag.

[0029] See attached document Figure 2 :

[0030] Example 1: Treatment of steel plant flue dust pickling solution

[0031] The raw material uses an H2SO4 system, containing 158 ppm Ge, 6.2 g / L Fe³+, 0.8 g / L Cu²+, and pH=0.9;

[0032] Operating parameters: Hastelloy C276 reactor, germanium liquid flow rate 5.2 m / s, tannin liquid flow rate 4.1 m / s; tannin excess ratio 18 times, nitrogen sheath flow pressure 0.3 MPa;

[0033] In this embodiment, the effluent Ge concentration is 3.5 ppm, the germanium precipitation rate is 97.8%, the slag contains 2.7% germanium, the Fe³+ entrainment rate is 7.2%, and the annual corrosion rate is <0.01 mm / a.

[0034] Case 1: Low-concentration germanium solution with Ge=60mg / L

[0035] The raw material used is: zinc smelting indium extraction solution with pH=1.2, containing 60 mg / L Ge, 4.8 g / L Fe³+, and 0.5 g / L In³+.

[0036] Operating parameters: Germanium precipitation solution: tannin volume ratio = 1:25, germanium: tannin flow rate ratio = 1:8; germanium solution flow rate 4.8 m / s, tannin solution flow rate 3.4 m / s, high shear to inhibit In³⁺ co-precipitation; tannin excess ratio 22 times.

[0037] In this case: the concentration of Ge in the germanium-precipitated liquid was 2.1 mg / L, with a germanium precipitation rate of 96.5%. The calculation formula for the germanium precipitation rate of 96.5% is 1 - 2.160 = 0.9651 - 602.1 = 0.965. The slag contained 2.8% germanium and <0.05% In, achieving efficient separation of Ge and In.

[0038] Case 2: Medium-to-high concentration germanium solution with Ge=180mg / L

[0039] The raw material used is a copper fume acid leaching solution with pH=0.8, containing 180 mg / L Ge, 7.5 g / L Fe³+, and 1.2 g / L Cu²+.

[0040] Operating parameters: Germanium precipitate: tannin volume ratio = 1:15, speed ratio = 1:10; germanium precipitate flow rate 6.0 m / s, turbulent mass transfer enhancement; tannin precipitate flow rate 2.6 m / s; tannin excess ratio 18 times; Na2SO3 pre-reducing agent is used, with 0.1 g / L added to convert Fe³⁺ to Fe²⁺.

[0041] In this case: the concentration of Ge in the solution after germanium precipitation is 8.6 mg / L, the germanium precipitation rate is 95.2%, and the calculation formula for the germanium precipitation rate is: 1 - 8.6180 = 0.9521 - 1808.6 = 0.952; the slag contains 3.1% germanium, the Cu entrainment is <0.3%, and the annual corrosion rate is <0.008 mm / a.

[0042] Case 3: High-concentration germanium solution with Ge=400mg / L

[0043] The raw material used is a germanium concentrate acid solution with pH=1.5, containing 400 mg / L Ge, 3.2 g / L Fe²+, and 2.4 g / L Zn²+.

[0044] Operating parameters: Germanium precipitation solution: tannin volume ratio = 1:10, speed ratio = 1:6; germanium solution flow rate 5.5 m / s, tannin solution flow rate 5.3 m / s, high shear inhibits Zn²+ adsorption; tannin excess ratio 15 times, 0.2% thiourea added to shield Fe²+.

[0045] In this case: the concentration of Ge in the solution after germanium precipitation is 18.4 mg / L, the germanium precipitation rate is 95.4%, and the calculation formula for the germanium precipitation rate is: 1 - 18.4 / 400 = 0.954 / 1 - 400 / 18.4 = 0.954; the slag contains 3.5% germanium, the amount of Zn entrained is <0.1%, and the tannin consumption is reduced by 30%.

[0046] Case 4: Complex impurity system with Ge = 120 mg / L

[0047] The raw material used is a lead-zinc slag pickling solution with pH=1.0, containing 120 mg / L Ge, 8.0 g / L Fe³+, and 0.3 g / L As³+.

[0048] Operating parameters: Germanium precipitation solution: tannin volume ratio = 1:20, speed ratio = 1:8; germanium solution flow rate 4.2 m / s, tannin solution flow rate 3.7 m / s; tannin excess ratio 25 times, and H2S gas at a rate of 0.05 L / min is simultaneously introduced to precipitate As³+.

[0049] In this case: the concentration of Ge in the germanium-precipitated liquid is 3.8 mg / L, the germanium precipitation rate is 96.8%, and the calculation formula for the germanium precipitation rate is: 1 - 3.8120 = 0.9681 - 1203.8 = 0.968; the slag contains 2.6% germanium and <0.01% As, which meets the environmental emission requirements.

[0050] Example 1 clearly shows that a Hastelloy C276 reactor was used, and the annual corrosion rate was <0.01 mm / a when treating a strong acid system. Examples 2-4 all operated stably in acidic environments, directly proving that 3D-printed corrosion-resistant materials solve the problems of traditional tannin-germanium precipitating reactors, which mostly use glass, silicon-based materials or ordinary stainless steel. These materials are prone to corrosion in strong acid environments with pH <1, resulting in short equipment life, high maintenance costs, and the risk of heavy metal leakage.

[0051] In Cases 1-4, the tannin excess ratio was 15-25 times, far lower than the 25-35 times required by traditional processes. Furthermore, all cases involved reactions at room temperature of 20-40℃, without mentioning a pH adjustment step. This improves upon the traditional tannin-germanium precipitation technology, which typically requires a tannin excess of 25-35 times, pH adjustment, and heating to 40-80℃. The excessive tannin consumption and additional operating conditions result in high tannin consumption, high energy consumption, and complex operation.

[0052] In Case 1, the In³⁺ entrainment rate was <0.05%; in Case 2, the Cu entrainment rate was <0.3%; in Case 3, the Zn entrainment rate was <0.1%; and in Case 4, the As content was <0.01%, all showing an impurity entrainment rate of <7%. Meanwhile, the germanium deposition rate in each case was >95%, thus improving the problem in the traditional tannin-deuterium deposition process where impurity ions easily form stable complexes with tannins. Due to the low efficiency of impurity competitive complexation and reaction contact, this resulted in low germanium selectivity, high impurity entrainment rate, and a germanium deposition rate of only 80-90%.

[0053] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wide-area germanium recovery equipment with a large-scale microreactor coupled with external focusing, comprising a 3D-printed corrosion-resistant microreactor body, a coaxial three-channel external focusing nozzle, and a multi-stage parallel modular structure, characterized in that, The 3D-printed corrosion-resistant microreactor body is made of Hastelloy C276, PEEK resin, and silicon carbide ceramic, with a channel size of 0.3-3mm. The coaxial three-channel external focusing nozzle includes a central tube, a middle annular gap, and an outer annular gap. The central tube is used to introduce germanium-containing waste liquid, the middle annular gap is used to introduce tannin liquid, and the outer annular gap is used to introduce gas sheath flow. The 3D-printed corrosion-resistant microreactor body and the coaxial three-channel external focusing nozzle can form an independent functional unit. The throughput of the independent functional unit is ≥50L / h, and multiple independent functional units can form a multi-level parallel modular structure. The pressure of the gas sheath flow is 0.1-0.6 MPa, and the droplet diameter of the gas sheath flow is 30-80 μm; the diameter of the central tube is 0.5-1.2 mm, and the flow velocity of the germanium-containing waste liquid in the central tube is 3-12 m / s; the width of the middle annular gap is 0.1-0.3 mm, and the flow velocity of the tannin liquid in the middle annular gap is 3-5 m / s; the width of the outer annular gap is 0.2-0.5 mm, and the flow velocity of the gas sheath flow in the outer annular gap is 5-10 m / s; the flow velocity ratio of the germanium-containing waste liquid to the tannin liquid is 1:6-1:

10.

2. The wide-area germanium recovery equipment with large-scale microreactor coupled to external focusing according to claim 1, characterized in that, The 3D-printed corrosion-resistant microreactor body is manufactured using selective laser melting (SLM) or DLP photopolymerization sintering. The surface roughness Ra of the 3D-printed corrosion-resistant microreactor body is ≤0.8μm, and the pressure resistance is >2MPa. The inlet section of the channel of the 3D-printed corrosion-resistant microreactor is provided with a tapered flow guide structure with a contraction angle of 15-30°. The outlet section of the channel of the 3D-printed corrosion-resistant microreactor is provided with a diffuser section with a diffusion angle of 10-20°.

3. The wide-area germanium recovery equipment with large-scale microreactor coupled to in vitro focusing according to claim 1, characterized in that, It also includes an online monitoring system, which comprises a germanium ion selective electrode and a flow controller. The germanium ion selective electrode is used to detect the concentration of germanium ions in germanium-containing waste liquid in real time, and the detection limit of the germanium ion selective electrode is 0.1 ppm. The flow controller is used to regulate the injection rate of tannin solution in real time. The inner wall of the channel of the 3D printed corrosion-resistant microreactor body is provided with a spiral turbulence structure, and the turbulence Reynolds number Re of the spiral turbulence structure is greater than 3000.

4. A wide-area germanium recovery method using a large-scale microreactor coupled with external focusing, applied to the wide-area germanium recovery equipment using a large-scale microreactor coupled with external focusing as described in any one of claims 1-3, characterized in that, Includes the following steps: Germanium-containing waste liquid is introduced into the central tube of a coaxial three-channel external focusing nozzle at a flow rate of 3-12 m / s; The tannin solution is introduced into the middle annular gap of the coaxial three-channel external focusing nozzle at a flow rate of 3-5 m / s, and the amount of tannin solution used is 5-20 times the molar amount of germanium. The gas sheath flow is introduced into the outer annular gap of the coaxial three-channel external focusing nozzle at a flow rate of 5-10 m / s to form droplets of 30-80 μm. The reaction is carried out under conditions of pH 0.5-1.5 and temperature 20-40℃, with a reaction residence time of <10 seconds, resulting in the formation of a precipitate; The precipitate formed by the reaction is collected and then calcined at a low temperature of 300-400℃.

5. The wide-area germanium recovery method using a large-scale microreactor coupled with in vitro focusing according to claim 4, characterized in that, The volume ratio of the germanium-containing liquid phase in the germanium-containing waste liquid to the tannin phase in the tannin liquid is 20:1-5:1; the germanium-containing waste liquid includes one or more of the following: zinc smelting germanium precipitation liquid, zinc smelting indium extraction liquid, steel plant flue dust containing germanium liquid, fly ash alkaline leaching liquid, copper flue dust acid leaching liquid, and lead-zinc slag pickling liquid.

6. The wide-area germanium recovery method using a large-scale microreactor coupled with in vitro focusing according to claim 4, characterized in that, When treating zinc smelting leaching solution, the germanium concentration in the germanium-containing waste liquid is 10-50 ppm, and the tannin solution is controlled to be 10-15 times in excess; when treating steel plant flue dust pickling solution, the germanium concentration in the germanium-containing waste liquid is 30-200 ppm, and the tannin solution is controlled to be 15-20 times in excess; the gas sheath flow is one or more of nitrogen and inert gas.

7. The application of the wide-area germanium recovery equipment coupled with in vitro focusing by a large-scale microreactor according to any one of claims 1-3, characterized in that, It can be applied to the wide range of germanium recovery from zinc smelting germanium precipitation solution, zinc smelting indium extraction solution, steel plant flue dust containing germanium solution, fly ash alkaline leaching solution, copper flue dust acid leaching solution, and lead-zinc slag pickling solution.

Images