Integrated microreactor and delayed pipe enhanced mass transfer pressure leaching system and method

Abstract

This invention discloses an integrated microreactor and delayed pipeline enhanced mass transfer pressurized leaching system and method, comprising: a slurry supply unit, a gas supply unit, a microreactor unit, a pressure regulation unit, a temperature control unit, a delayed reaction unit, and a separation and recovery unit. When processing sphalerite, this invention achieves a zinc leaching rate of 99.7% in 45 seconds of micro-reaction plus a 3-minute delay, with a unit volume processing capacity of 18 t / (m³·h). It reduces alkali consumption by 26% when processing monohydrate bauxite and acid consumption by 35% when recovering waste lithium batteries. Through parallel module expansion, the single module processing capacity is 0.5-10 t / h, with comprehensive energy consumption reduced to 30-60% of traditional processes and a floor space reduction of 85%. It is applicable to five major fields: sphalerite, bauxite, gold ore, waste lithium batteries, and platinum group metals recovery.

Description

Technical Field

[0001] This invention relates to the fields of hydrometallurgy, resource recovery and chemical process technology, and in particular to an integrated microreactor and time-delayed pipeline enhanced mass transfer pressurized leaching system and method. Background Technology

[0002] In traditional hydrometallurgical processes, pressure leaching technology has been widely used to process refractory ores and secondary resources. Conventional processes often employ high-pressure autoclave reactors, which have the following technical drawbacks: 1. Low reaction efficiency: In traditional autoclaves, the gas-liquid-solid three-phase contact is insufficient, the bubble size is large (usually on the order of millimeters), the interface area is limited, and the mass transfer rate is slow, resulting in a long reaction time (usually several hours), and the metal leaching rate needs to be improved.

[0003] 2. High energy consumption: Maintaining high temperature and high pressure conditions for extended periods requires a large amount of energy. Taking pressurized oxygen leaching of sphalerite as an example, the traditional process requires a reaction time of 60-120 minutes at 180-250℃ and 1-2MPa, resulting in significant heat loss.

[0004] 3. Poor safety: Large high-pressure vessels (usually 10-100m³) pose safety hazards such as leakage and explosion during long-term operation at high temperature and high pressure, and the emergency pressure relief system has a delayed response.

[0005] 4. High equipment investment: High pressure vessels and their auxiliary equipment are large in size, occupy a large area, have high initial investment, and expensive maintenance costs.

[0006] 5. Low control precision: Poor temperature and pressure control precision, often with obvious gradients, affecting reaction selectivity and product purity.

[0007] However, although there have been attempts to improve the reactor structure in existing technologies, none of them have fundamentally solved the above problems.

[0008] Although microreactor technology has been applied in the chemical industry, it is mainly limited to homogeneous or two-phase reactions. There are no reports of successful applications in complex three-phase reaction systems such as hydrometallurgy.

[0009] Pressure leaching technology has been used in traditional hydrometallurgy and resource recovery for decades. While conventional high-pressure autoclave leaching processes can handle refractory ores and complex materials, they have several inherent drawbacks: Traditional equipment for gas-liquid-solid three-phase reaction systems suffers from long reaction times (typically several hours to tens of hours), large equipment size, low mass transfer efficiency, poor temperature and pressure control precision, high safety risks, and high energy consumption. In particular, for gas-liquid-solid three-phase reaction systems, the large bubble size (typically on the millimeter scale), limited gas-liquid contact area, and easy sedimentation and accumulation of solid particles in traditional equipment result in severe diffusion control of the reaction rate.

[0010] Traditional pressurized oxygen leaching processes for sphalerite require a reaction time of 60-120 minutes in an autoclave at 180-250°C and 1-2 MPa oxygen pressure, achieving a zinc leaching rate of approximately 95-98%. Gold ore desulfurization and dearsenic removal pretreatment requires several hours of reaction under high-pressure oxygen atmosphere, while the cyanide leaching process requires an additional 24-72 hours. These extended periods not only increase equipment investment and operating costs but also pose significant safety hazards—high-pressure vessels are prone to corrosion, leakage, and even explosions during prolonged operation.

[0011] However, pressure leaching technology under microreactor conditions fundamentally overturns the traditional reaction engineering paradigm of hydrometallurgy. Its innovation is mainly reflected in the following aspects: 1. Application of the principles of microscale reaction engineering The core feature of microreactors lies in their micrometer-scale channel structure (typically 50-500 μm). When the slurry and gas enter from two separate inlets, special structural units within the channels (such as T-type mixers, cross-flow focusers, and multi-stage Venturi structures) cut the two-phase fluids into: Droplet size: 10-200μm; Bubble size: 5-100μm (micro-nano bubbles); Solid particles: pre-ground to a suitable size (e.g., sphalerite particle size D90 < 45 μm); According to mass transfer theory, the mass transfer coefficient is directly proportional to the interface area and inversely proportional to the diffusion distance.

[0012] The microscale environment created by microreactors enables: The gas-liquid interface area is increased by 2-3 orders of magnitude compared to traditional equipment (up to 5000-15000 m² / m³). The liquid-solid contact distance is reduced to the micrometer level; The diffusion time constant (t∝L² / D) is reduced from the minute level to the millisecond level; 2. Precise coordinated control of high pressure and high temperature Traditional autoclave temperature control relies on external jacket heating, resulting in a significant temperature gradient (the temperature difference between the autoclave center and the wall can reach 20-50℃).

[0013] The highly efficient heat exchange structures integrated into microreactors (such as microchannel heat exchangers and thin-film heat exchangers) can: Achieve uniform heating / cooling of fluids within milliseconds; Temperature control accuracy can reach ±0.5℃ (compared to ±5-10℃ for traditional equipment); The back pressure valve enables precise adjustment of pressure from 1 to 10 MPa, with pressure fluctuations of <0.1 MPa.

[0014] This precise control is crucial for reaction kinetics.

[0015] Taking pressurized oxygen leaching of sphalerite as an example: ZnS + H2SO4 + ½O2 → ZnSO4+ H2O + S 0 ; The reaction rate constant k exhibits an Arrhenius relationship with temperature: k = A e^{-E_a / (RT) When the temperature is increased from 180℃ to 220℃ (an increase of only 40℃), the reaction rate can be increased by 3-5 times. In addition, if the pressure of the reaction gas is increased by tens of times, the reaction rate can also be rapidly increased.

[0016] Traditional equipment often employs conservative operating conditions due to imprecise temperature control, while microreactors allow safe operation at temperatures close to the thermal stability limits of the reactants.

[0017] 3. Innovative Design of Delayed Pipeline Flow Reactor While microreactors themselves have extremely high mass transfer efficiency, the reaction time is typically only a few seconds to tens of seconds. For certain complex processes that require a certain reaction time (such as arsenic removal in gold ore or leaching of valuable metals from spent lithium-ion batteries), it is necessary to install a device at the downstream end of the microreactor. Insulated pipes: adopt a multi-layer insulation structure (inner layer of corrosion-resistant alloy, middle vacuum insulation layer, outer layer of insulation material); Pressure-holding design: utilizing the pipeline's own pressure-bearing capacity and pressure compensation system; Controllable residence time: Adjusted by pipe length and flow rate (usually designed to be 1-30 minutes); This design achieves an optimized combination of "rapid mixing + full reaction", which not only leverages the high-efficiency mass transfer advantage of microreactors, but also ensures the necessary degree of reaction completion.

[0018] Compared with traditional technologies from multiple perspectives, it has the following advantages: 1. Comparison of reaction efficiencies Taking pressurized oxygen leaching of sphalerite as an example: Table 1 shows a comparison of the system parameters of traditional autoclaves and microreactors. Table 1:

[0019] 2. Energy consumption comparison The energy consumption of traditional autoclaves mainly comes from: heating energy consumption for maintaining high temperature for a long time, mechanical energy consumption of the stirrer, and energy consumption of oxygen compression; Energy-saving mechanism of microreactor system: Rapid response reduces heat loss (heat loss is proportional to time); The laminar flow characteristics of microchannels reduce flow resistance (pressure drop is only 1 / 10 to 1 / 100 of that of traditional systems). Precise temperature control prevents overheating and waste; High oxygen utilization reduces compression energy consumption; Overall energy consumption can be reduced by 40-70%.

[0020] 3. Comparison of safety performance Safety hazards of traditional autoclaves: Explosion risk of large-volume high-pressure vessels (typically 10-100m³); Stress corrosion of materials under high temperature and high pressure conditions; Response delay of emergency pressure relief system; Safety advantages of microreactor systems: The "intrinsically safe" characteristic of microchannels: even if a leak occurs, the instantaneous energy released is extremely small; Fast response: Temperature and pressure sensors are integrated with the control system, with a response time of <100ms; Modular design: damage to a single module does not affect the overall operation of the system.

[0021] 4. Equipment investment and operating costs Although the microreactor unit requires high processing precision, and the initial investment may be comparable to or slightly higher than that of traditional equipment, considering all factors: The footprint is reduced by 80-90% (no need for a large autoclave plant); Installation and commissioning time reduced by 50-70%; Reduced maintenance costs (no large agitators, seals, or other easily damaged parts); High degree of automation reduces labor costs; The total life cycle cost can be reduced by 30-50%.

[0022] Therefore, in order to solve the problems existing in the prior art, it is an urgent technical problem for those skilled in the art to provide a microreactor pressure leaching system and method with high reaction efficiency, low energy consumption, good safety, flexible operation and applicability to various hydrometallurgical processes. Summary of the Invention

[0023] In view of this, the present invention provides an integrated microreactor and time-delayed pipeline enhanced mass transfer pressurized leaching system and method.

[0024] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: An integrated microreactor and extended-time pipeline enhanced mass transfer pressurized leaching system includes: a slurry supply unit, a gas supply unit, a microreactor unit, a pressure regulation unit, a temperature control unit, an extended-time reaction unit, and a separation and recovery unit; wherein, The slurry supply unit includes a slurry storage tank, a slurry pump, and a flow meter, and is used to transport the slurry formed by mixing solid materials with leaching agents. The gas supply unit includes a gas storage tank, a compressor, and a pressure reducing valve, and is used to supply oxygen, air, or reaction gas. The microreactor unit includes at least one microreactor body with a microchannel structure inside, and at least two inlets connected to the slurry and gas supply units respectively, and one outlet connected to the subsequent unit. The pressure regulating unit includes a back pressure valve and a pressure sensor, located at the outlet of the microreactor, to maintain the system pressure at 1-10 MPa. The temperature control unit includes an integrated heat exchange structure, a temperature sensor, and a heating / cooling system, and controls the reaction temperature to 120-300℃. The delayed reaction unit is a heat-insulated and pressure-maintaining pipe connected to the outlet of the microreactor, with an external insulation layer and pressure compensation system. The separation and recovery unit includes a gas-liquid separator and a solid-liquid separation device.

[0025] Preferably, the microchannel structure is selected from one or more combinations of the following: T-type / Y-type hybrid structure Crossflow focusing structure Venturi structure Multi-level branch-and-converge structure; The channel size of the microchannel structure is 50-500 μm.

[0026] Preferably, the heat exchange structure is a microchannel heat exchanger with a channel size of 100-500μm, which is arranged alternately with or coaxially with the reaction channels.

[0027] Preferably, the heat-insulating and pressure-maintaining pipe has a multi-layer composite structure, which includes, from the inside out: a corrosion-resistant alloy layer, a vacuum insulation layer, a nano-aerogel insulation layer, and a stainless steel protective layer. The inner diameter of the insulated and pressure-maintaining pipe is 5-50mm, and the length is 10-200m.

[0028] Preferably, the microreactor unit achieves capacity scaling by connecting multiple modules in parallel, with a single module processing capacity of 0.5-10 t / h; The system has a processing capacity of 5-20 t / (m³·h) per unit volume.

[0029] An integrated microreactor and time-delayed pipeline enhanced mass transfer pressurized leaching method includes the following steps: S1: Crush solid materials to D90<50μm and mix with leaching agent to form slurry; S2: Pump the slurry into the first inlet of the microreactor, and introduce the reaction gas into the second inlet; S3: The slurry is cut into 10-200μm droplets and the gas is dispersed into 5-100μm microbubbles in the microchannel, forming a gas-liquid-solid three-phase system; S4: Adjust the pressure to 1-10MPa via the back pressure valve, and control the temperature to 120-300℃ via the heat exchanger; S5: After the material stays in the microreactor for 10-120 seconds, it enters the delay pipeline and reacts for 1-30 minutes. S6: Separates gaseous, liquid and solid products.

[0030] Preferably, in step S3, the average diameter of the generated micro-nano bubbles is 5-100 μm, and the average diameter of the droplets is 10-200 μm.

[0031] Preferably, in step S4, the pressure control accuracy is ±0.1MPa and the temperature control accuracy is ±0.5℃. In step S4, the pressure and temperature are dynamically stabilized through PID closed-loop control, with fluctuation ranges of ≤±0.1MPa and ±0.5℃, respectively.

[0032] Preferably, the method is applicable to any of the following processes: Pressurized oxygen leaching of sphalerite: temperature 180-250℃, pressure 1-3MPa, total reaction time 2-10 minutes; Soda leaching of monohydrate diaspore: temperature 250-300℃, pressure 6-10MPa, total reaction time 5-15 minutes; Desulfurization and arsenic removal in gold mines: temperature 180-220℃, pressure 2-4MPa, total reaction time 5-20 minutes; Waste lithium-ion battery recycling: temperature 100-150℃, pressure 1-3MPa, total reaction time 3-10 minutes; Platinum group metals recovery: temperature 150-200℃, pressure 2-5MPa, total reaction time 5-15 minutes.

[0033] Preferably, the metal leaching rate after the reaction is ≥99.5% and the oxygen utilization rate is ≥95%.

[0034] The present invention achieves the following technical effects compared to the prior art: (1) Significantly improved reaction efficiency: The microreactor of this invention creates a huge interfacial area, with a gas-liquid interfacial area of ​​5000-15000 m² / m³, eliminating mass transfer limitations, reducing the reaction time from several hours in traditional processes to several minutes, and increasing the metal leaching rate by 1-5%; (2) Significantly reduced energy consumption: The rapid response of this invention reduces heat loss, precise temperature control avoids energy waste, and high gas utilization reduces compression energy consumption, resulting in a 40-70% reduction in overall energy consumption; (3) Significantly improved safety: The microreactor of this invention has the characteristics of "intrinsic safety", small liquid holding capacity and fast response, which fundamentally eliminates the risk of explosion of large high-pressure vessels. The modular design improves the reliability of the system. (4) Compact equipment and reduced investment: The system volume of the present invention is only 1 / 10 to 1 / 100 of that of traditional equipment, and the floor space is reduced by 80-90%. The modular design facilitates installation and maintenance, and the total life cycle cost is reduced by 30-50%. (5) High control precision and good product quality: The precise temperature and pressure control of this invention (±0.5℃, ±0.1MPa) improves reaction selectivity, reduces side reactions, and results in higher product purity; (6) Wide range of applications and good flexibility: The same system of the present invention can handle a variety of materials by adjusting the operating parameters, which is especially suitable for small and medium-sized production needs with multiple varieties. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the system of the present invention.

[0036] In the diagram: 100-Slurry Supply Unit: 1-Slurry Storage Tank; 2-Leaching Agent Storage Tank; 3-Reaction Slurry Preheating Unit; 4-Slurry Pump and Flow Meter; 5-Slurry Conveying Screw Pump; 6-Gas Supply Unit; 200-Micro-Reaction Unit: 7-Safety Valve; 8-Gas-Liquid-Solid Micro-Reaction Shear Heat Exchanger; 9-Temperature Controller; 10-Anti-Clogging Micro-Reaction Unit; 11-Safety Valve; 12-Delayed Reaction Unit; 300-Electrical Control Cabinet Control System; 16-Temperature Control Unit; 17-Pressure Regulating Unit; 13-Back Pressure Valve; 400-Separation and Recovery Unit: 14-Gas-Liquid Separator; 15-Solid-Liquid Separation Equipment; 18-Slurry Circulation Leaching System. Detailed Implementation

[0037] The technical solutions of 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.

[0038] This invention discloses an integrated microreactor and delayed-reaction pipeline enhanced mass transfer pressurized leaching system, comprising: a slurry supply unit, a gas supply unit, a microreactor unit, a pressure regulating unit, a temperature control unit, a delayed-reaction unit, and a separation and recovery unit; wherein, Slurry supply unit: including slurry storage tank, slurry pump and flow meter, used to transport slurry formed by mixing solid materials with leaching agent; Gas supply unit: includes gas storage tank, compressor and pressure reducing valve, used to supply oxygen, air or reaction gas; Microreactor Unit: Includes at least one microreactor body with a microchannel structure inside, and at least two inlets connected to the slurry and gas supply units respectively, and one outlet connected to the subsequent unit; Pressure regulating unit: including back pressure valve and pressure sensor, located at the outlet of microreactor, to maintain system pressure 1-10MPa; Temperature control unit: includes integrated heat exchange structure, temperature sensor and heating / cooling system, controls reaction temperature 120-300℃; Delayed reaction unit: Insulated and pressure-maintaining pipe connected to the outlet of the microreactor, with an external insulation layer and pressure compensation system; Separation and recovery unit: includes gas-liquid separator and solid-liquid separation equipment.

[0039] The microchannel structure is selected from one or more of the following combinations: T-type / Y-type hybrid structure Crossflow focusing structure Venturi structure Multi-level branch-and-converge structure; The channel size of the microchannel structure is 50-500 μm.

[0040] The heat exchange structure is a microchannel heat exchanger with a channel size of 100-500μm, which is arranged alternately with or coaxially with the reaction channels.

[0041] The insulated and pressure-resistant pipe has a multi-layer composite structure, which includes, from the inside out: a corrosion-resistant alloy layer, a vacuum insulation layer, a nano-aerogel insulation layer, and a stainless steel protective layer. The inner diameter of the insulated and pressure-resistant pipe is 5-50mm, and the length is 10-200m.

[0042] The microreactor unit achieves capacity scaling by connecting multiple modules in parallel, with a single module having a processing capacity of 0.5-10 t / h; The system has a processing capacity of 5-20 t / (m³·h) per unit volume.

[0043] This invention also discloses an integrated microreactor and time-delayed pipeline enhanced mass transfer pressurized leaching method, comprising the following steps: S1: Crush solid materials to D90<50μm and mix with leaching agent to form slurry; S2: Pump the slurry into the first inlet of the microreactor, and introduce the reaction gas into the second inlet; S3: The slurry is cut into 10-200μm droplets and the gas is dispersed into 5-100μm microbubbles in the microchannel, forming a gas-liquid-solid three-phase system; S4: Adjust the pressure to 1-10MPa via the back pressure valve, and control the temperature to 120-300℃ via the heat exchanger; S5: After the material stays in the microreactor for 10-120 seconds, it enters the delay pipeline and reacts for 1-30 minutes. S6: Separates gaseous, liquid and solid products.

[0044] In step S3, the average diameter of the generated micro-nano bubbles is 5-100 μm, and the average diameter of the droplets is 10-200 μm.

[0045] In step S4, the pressure control accuracy is ±0.1MPa and the temperature control accuracy is ±0.5℃. In step S4, pressure and temperature are dynamically stabilized through PID closed-loop control, with fluctuation ranges of ≤±0.1MPa and ±0.5℃, respectively.

[0046] The method is applicable to any of the following processes: Pressurized oxygen leaching of sphalerite: temperature 180-250℃, pressure 1-3MPa, total reaction time 2-10 minutes; Soda leaching of monohydrate diaspore: temperature 250-300℃, pressure 6-10MPa, total reaction time 5-15 minutes; Desulfurization and arsenic removal in gold mines: temperature 180-220℃, pressure 2-4MPa, total reaction time 5-20 minutes; Waste lithium-ion battery recycling: temperature 100-150℃, pressure 1-3MPa, total reaction time 3-10 minutes; Platinum group metals recovery: temperature 150-200℃, pressure 2-5MPa, total reaction time 5-15 minutes.

[0047] After the reaction, the metal leaching rate is ≥99.5% and the oxygen utilization rate is ≥95%.

[0048] Example 1: Pressure oxygen leaching of sphalerite The system of the present invention is used to process sphalerite concentrate containing 15% zinc (particle size D90=38μm). The slurry supply unit pumps 30% solid slurry (adjusted to pH=1.5 with dilute sulfuric acid) into the microreactor unit at a flow rate of 8 t / h. The unit consists of 64 parallel microchannel modules (channel size 200μm, T-type hybrid structure), and the gas supply unit is supplied with 2.5 MPa pure oxygen; The temperature control unit precisely maintains the reaction temperature at 220±0.3℃ through a coaxial microchannel heat exchanger (150μm channel), and the pressure regulation unit stabilizes the system pressure with an electric back pressure valve (accuracy ±0.08 MPa). The slurry is cut into 50-100μm droplets in the microchannel, and oxygen is dispersed into 10-30μm microbubbles. After a micro-reaction of 45 seconds, it enters a multi-layer composite time-delay pipe (25mm inner diameter / 60m length, Hastelloy C276 inner layer + vacuum insulation layer + nano aerogel), and continues to react for 3 minutes under heat preservation and pressure preservation conditions. The final slurry is processed by a separation and recovery unit: the gas-liquid separator recovers unreacted oxygen (recycling rate 97.5%), and the solid-liquid separation yields leachate (zinc leaching rate 99.7%, iron leaching rate only 1.8%). The system has a unit volume processing capacity of 18 t / (m³·h) (compared to 0.2 t / (m³·h) for a traditional autoclave), energy consumption of 0.8 tons of standard coal / ton of zinc (compared to 1.5 tons for a traditional autoclave), and a floor space reduction of 85%.

[0049] Example 2: Leaching with diaspore monohydrate Low-grade bauxite (Al2O3 45%, SiO2 15%) was processed by feeding the slurry (200 g / L NaOH solution, solid content 25%) into a Venturi microreactor (channel 300 μm) at a flow rate of 6 t / h. The gas supply unit injects 8 MPa of saturated steam to maintain the pressure, and the temperature control unit precisely controls the reaction temperature at 280±0.5℃ through alternating microchannel heat exchangers. The material is kept in the microreactor for 60 seconds to form a nanoscale mixing system, and then enters a 50m delay pipe (with an outer nano-aerogel insulation layer, heat loss <1℃) for 7 minutes to react. The leachate produced by the separation and recovery unit has an aluminum leaching rate of 94.2%, a silicon removal rate of 88.3%, and an alkali consumption of 85 kg / t ore (compared to 115 kg / t in the traditional method). The system adopts a cross-flow focusing + Venturi combined microchannel, with a unit volume processing capacity of 12 t / (m³·h) (compared to 0.4 t / (m³·h) for traditional autoclaves), and the overall energy consumption is 45% of that of the traditional process, verifying the feasibility of the high-temperature alkaline leaching process in right 7.

[0050] Example 3: Pretreatment for desulfurization and arsenic removal in gold ore Arsenic-containing gold concentrate (Au 35g / t, As 2.5%, S 18%) was processed by simultaneously pumping the slurry (dilute sulfuric acid + 0.5 mol / L Fe³⁺ oxidant) and 3.2 MPa oxygen into a cross-flow focusing microreactor (channel 100μm). The temperature control unit maintains 200±0.5℃, and the pressure regulation accuracy is ±0.1 MPa. After the three-phase system stays in the microchannel for 50 seconds, it reacts for 11 minutes through a 20mm / 40m inner diameter delay pipe (Hastelloy B3 lining).

[0051] Results: Desulfurization rate was 96.5%, arsenic removal rate was 94.8%, and subsequent cyanide leaching gold rate increased to 98.2% (compared to only 65% ​​without treatment). The system achieves a processing capacity of 10 t / h by connecting 12 microreactor modules in parallel, with a total reaction time of 12 minutes (compared to 4 hours for traditional pretreatment), reducing unit energy consumption by 55%. The microreactor outlet is equipped with a multi-stage diversion-convergence structure to ensure uniform dispersion of arsenic slag particles.

[0052] Example 4: Recycling of Waste Lithium-ion Batteries The lithium iron phosphate battery cathode material (Li 3.5%, Fe 35%) was processed by feeding a slurry (1.5 mol / L H2SO4 + 3% H2O2) into a Y-type micro-mixing reactor (channel 150μm) at a flow rate of 5 t / h. The gas supply unit provides 1.5 MPa of oxygen, and the temperature control unit maintains 120±0.3℃ through a coaxial micro heat exchange channel; the material undergoes a 30-second micro-reaction before entering a 15mm / 30m inner diameter delay pipe (titanium inner layer + stainless steel protective layer) for a 5.5-minute reaction. The leachate produced by the separation and recovery unit has the following leaching rates: lithium leaching rate 99.3%, iron leaching rate 98.5%, copper / aluminum leaching rate <0.5%, and acid consumption of 1.8 tons of sulfuric acid per ton of material (compared to 2.8 tons for conventional materials). The system consists of 80 parallel modules with a total volume of only 2.4 m³ (equivalent to 1 / 50 of traditional equipment), and its comprehensive energy consumption is 38% of that of traditional autoclaves, with an 85% reduction in waste gas emissions.

[0053] Example 5: Platinum Group Metals Recovery Waste automotive catalysts (800 ppm platinum group metals) are treated by feeding a slurry (diluted aqua regia HCl:HNO3=3:1, diluted 8 times) into a multi-stage split-combination microreactor (500μm channel) at a flow rate of 3 t / h. Chlorine gas (partial pressure 0.8 MPa, total system pressure 3 MPa) is introduced into the gas supply unit, and the temperature control unit maintains 180±0.4℃ through a microchannel heat exchanger array. After the material stays in the microreactor for 80 seconds, it enters a multi-layer composite time-delay pipeline (inner layer Hastelloy C-22, vacuum insulation layer with thermal conductivity of 0.015 W / (m·K)) and reacts for 11.2 minutes. Results: The leaching rates of Pt / Pd / Rh reached 99.8% / 99.5% / 98.9%, respectively, and acid consumption was reduced by 62%. The system adopts a four-layer composite pipeline structure with a liquid holdup of <100 L. Through modular parallel connection, it achieves a unit processing capacity of 15 t / (m³·h) (compared to 0.3 t / (m³·h) in the traditional process), and reduces the footprint by 90%.

[0054] Working principle of the device This system achieves enhanced leaching through a combination of micro-reaction instantaneous mixing and delayed deep reaction in pipelines: The slurry is pumped into the microreactor unit (channels 50-500μm) via a supply unit. In the T-type / Venturi structure, the slurry is broken into 10-200μm droplets, and the gas is dispersed into 5-100μm microbubbles, completing three-phase nanoscale mixing of gas, liquid, and solid within 10-120 seconds. The mixture flows into an insulated and pressure-maintaining pipeline (inner diameter 5-50mm, including a vacuum insulation layer and a thermal insulation layer), where it reacts continuously for 1-3 minutes at 1-10 MPa and 120-300℃, maintained by a pressure regulating unit (±0.1MPa) and a temperature control unit (±0.5℃). Dynamic thermal equilibrium is achieved through a microchannel heat exchanger (100-500μm). Parallel module groups (0.5-10 t / h per module) enable a unit volume processing capacity of 5-20 t / h. With a yield of t / (m³·h), a typical example is the zinc leaching rate of 99.7% achieved in sphalerite processing with a micro-reaction time of 45 seconds plus a 3-minute delay. The final product is gas and solid-liquid products after separation and recovery. The system comprehensively reduces alkali consumption by 26% (diaspore monohydrate) and acid consumption by 35% (waste lithium batteries). The overall energy consumption is only 30-60% of that of traditional processes, and the floor space is reduced by 85%. It covers five major areas: sphalerite, bauxite, gold mine, waste lithium batteries, and platinum group metals recycling.

[0055] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. Integrated microreactor with holdup pipe enhanced mass transfer pressurized leaching system characterized in that, include: The system includes a slurry supply unit, a gas supply unit, a microreactor unit, a pressure regulation unit, a temperature control unit, a delayed reaction unit, and a separation and recovery unit; among which, The slurry supply unit includes a slurry storage tank, a slurry pump, and a flow meter, and is used to transport the slurry formed by mixing solid materials with leaching agents. The gas supply unit includes a gas storage tank, a compressor, and a pressure reducing valve, and is used to supply oxygen, air, or reaction gas. The microreactor unit includes at least one microreactor body with a microchannel structure inside, and at least two inlets connected to the slurry and gas supply units respectively, and one outlet connected to the subsequent unit. The pressure regulating unit includes a back pressure valve and a pressure sensor, located at the outlet of the microreactor, to maintain the system pressure at 1-10 MPa. The temperature control unit includes an integrated heat exchange structure, a temperature sensor, and a heating / cooling system, and controls the reaction temperature to 120-300℃. The delayed reaction unit is a heat-insulated and pressure-maintaining pipe connected to the outlet of the microreactor, with an external insulation layer and pressure compensation system. The separation and recovery unit includes a gas-liquid separator and a solid-liquid separation device.

2. The integrated microreactor with holdup pipe intensified mass transfer pressurized leaching system according to claim 1, characterized in that, The microchannel structure is selected from one or more combinations of the following: T-type / Y-type hybrid structure Crossflow focusing structure Venturi structure Multi-level branch-and-converge structure; The channel size of the microchannel structure is 50-500 μm.

3. The integrated microreactor with holdup pipe reinforced mass transfer pressurized leaching system according to claim 1, wherein, The heat exchange structure is a microchannel heat exchanger with a channel size of 100-500μm, which is arranged alternately with or coaxially with the reaction channels.

4. The integrated microreactor with holdup pipe reinforced mass transfer pressurized leaching system according to claim 1, wherein, The heat-insulating and pressure-maintaining pipe has a multi-layer composite structure, which includes, from the inside out: a corrosion-resistant alloy layer, a vacuum insulation layer, a nano-aerogel insulation layer, and a stainless steel protective layer. The inner diameter of the insulated and pressure-maintaining pipe is 5-50mm, and the length is 10-200m.

5. The integrated microreactor and delayed-phase pipeline enhanced mass transfer pressurized leaching system according to claim 1, characterized in that, The microreactor unit achieves capacity scaling by connecting multiple modules in parallel, with a single module processing capacity of 0.5-10 t / h; The system has a processing capacity of 5-20 t / (m³·h) per unit volume.

6. The process of pressure leaching with enhanced mass transfer by integration of microreactor with holdup pipe characterized in that, Includes the following steps: S1: Crush solid materials to D90<50μm and mix with leaching agent to form slurry; S2: Pump the slurry into the first inlet of the microreactor, and introduce the reaction gas into the second inlet; S3: The slurry is cut into 10-200μm droplets and the gas is dispersed into 5-100μm microbubbles in the microchannel, forming a gas-liquid-solid three-phase system; S4: Adjust the pressure to 1-10MPa via the back pressure valve, and control the temperature to 120-300℃ via the heat exchanger; S5: After the material stays in the microreactor for 10-120 seconds, it enters the delay pipeline and reacts for 1-30 minutes. S6: Separates gaseous, liquid and solid products.

7. The integrated microreactor and holdup pipe intensified mass transfer pressurized leaching process according to claim 6, characterized in that, In step S3, the average diameter of the generated micro-nano bubbles is 5-100 μm, and the average diameter of the droplets is 10-200 μm.

8. The integrated microreactor and holdup pipe intensified mass transfer pressurized leaching process according to claim 6, characterized in that, In step S4, the pressure control accuracy is ±0.1MPa and the temperature control accuracy is ±0.5℃. In step S4, the pressure and temperature are dynamically stabilized through PID closed-loop control, with fluctuation ranges of ≤±0.1MPa and ±0.5℃, respectively.

9. The integrated microreactor and holdup pipe mass transfer enhanced pressure leaching process in accordance with claim 6, wherein, The method is applicable to any of the following processes: Pressurized oxygen leaching of sphalerite: temperature 180-250℃, pressure 1-3MPa, total reaction time 2-10 minutes; Soda leaching of monohydrate diaspore: temperature 250-300℃, pressure 6-10MPa, total reaction time 5-15 minutes; Desulfurization and arsenic removal in gold mines: temperature 180-220℃, pressure 2-4MPa, total reaction time 5-20 minutes; Waste lithium-ion battery recycling: temperature 100-150℃, pressure 1-3MPa, total reaction time 3-10 minutes; Platinum group metals recovery: temperature 150-200℃, pressure 2-5MPa, total reaction time 5-15 minutes.

10. The integrated microreactor and holdup pipe mass transfer enhanced pressure leaching process in accordance with claim 6, wherein, After the reaction, the metal leaching rate is ≥99.5% and the oxygen utilization rate is ≥95%.

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