Method and system for in-situ strengthening acid leaching and synchronous extraction of indium and germanium by multi-parameter coupling regulation

Abstract

The application discloses a method and system for in-situ strengthening acid leaching and synchronous extraction of indium and germanium by multi-parameter coupling control, and relates to the technical field of hydrometallurgy of dispersed metals. The specific steps of the method are as follows: mineralization pretreatment is performed on raw materials to calibrate parameters, fuming enrichment is performed to obtain indium-germanium-containing fume dust and fine-tune parameters, coupling acid leaching is performed to realize synchronous and efficient leaching of indium and germanium, gradient separation is performed to recover indium and germanium and calibrate process parameters, finally, intelligent management and control systems are relied on to optimize process and equipment parameters in the whole process, and continuous and stable industrial production is realized. The application realizes efficient synchronous extraction and accurate separation of indium and germanium, solves the problems of low leaching rate and resource waste in traditional processes, and builds a material closed-circuit system, which promotes the upgrading of automatic and intelligent recovery of dispersed metals, improves the comprehensive utilization efficiency of by-products of zinc smelting, helps the industry to form a green and low-carbon circular economic mode, and provides strong support for efficient utilization of strategic resources and high-quality development of non-ferrous metal industry.

Description

Technical Field

[0001] This invention relates to the field of rare and dispersed metal hydrometallurgy technology, specifically to a method and system for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium by multi-parameter coupling control. Background Technology

[0002] Indium and germanium, as important rare and dispersed metals, are core strategic materials supporting the development of high-tech fields such as semiconductors, optoelectronics, new energy, and military industry. They occupy an irreplaceable position in modern industrial systems and national defense security. All countries list them as key raw materials and strategic reserves. Indium and germanium are extremely rare in the earth's crust and have no independent mining value. They mostly occur as isomorphous substances in non-ferrous metal minerals such as zinc and lead. Leaching slag and secondary zinc oxide dust produced in the zinc smelting process are the main raw materials for indium and germanium recovery. my country is a major country in terms of global indium and germanium reserves and production, undertaking most of the global indium and germanium supply. With the rapid development of emerging industries, the market demand for indium and germanium continues to grow. The efficient extraction of indium and germanium from zinc smelting by-products has become an important measure to improve the comprehensive utilization efficiency of resources and ensure the stable supply of my country's strategic metal resources. It also promotes the upgrading of the zinc smelting industry towards the high-value utilization of resources.

[0003] Traditional processes for recovering indium and germanium from zinc smelting byproducts suffer from numerous technical shortcomings, failing to meet the demands for efficient and comprehensive recovery. In the fumigation enrichment stage, traditional processes cannot precisely control furnace temperature and atmosphere, resulting in low indium and germanium volatilization efficiency and significant loss of valuable metals with the waste residue. Furthermore, the limited pretreatment methods for raw materials make it difficult to disrupt the silicate and iron oxide encapsulation structures of indium and germanium. Silicon impurities can also form interfering phases, further reducing enrichment efficiency. Conventional acid leaching processes struggle to dissociate complex indium and germanium compounds from the flue gas, resulting in low leaching rates. Moreover, the acid leaching process lacks dynamic monitoring and control of system parameters, leading to haphazard reagent addition and potential interference from co-dissolved impurities. Indium and germanium separation often employs a single recovery model, exhibiting poor raw material adaptability. The extraction process is prone to emulsification and organic phase aging issues. Additionally, the lack of effective coordination and process synergy between different stages, coupled with the absence of a systematic intelligent management system, results in a low overall recovery rate of indium and germanium, causing severe resource waste. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method and system for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium by multi-parameter coupling control. It integrates five major processes: mineralization pretreatment, fumigation enrichment, coupled acid leaching, gradient separation, and intelligent control. The raw material properties are optimized through mechanical activation and dilute sulfuric acid pre-leaching. The gradient heating and atmosphere control of the fumigation furnace achieve efficient enrichment of indium and germanium. Parameters such as pH, ORP, and chloride ion concentration are monitored in real time in a closed reaction vessel. Based on the leaching coupling control algorithm, reagents are dynamically added to precisely control the acid leaching process, ensuring simultaneous and efficient leaching of indium and germanium, and realizing multi-metal stepwise separation and recovery.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: On the one hand, a method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium by multi-parameter coupling regulation, the method comprising:

[0006] S100, mineralization pretreatment: quantitative analysis and mineralogical analysis of the components of indium, germanium and zinc smelting raw materials are carried out. Based on the analysis results, the raw materials are mechanically activated, pre-leached with dilute sulfuric acid and treated with additives in sequence. The basic parameters of the raw materials are calibrated for the leaching coupling control algorithm, so as to provide suitable materials for subsequent indium and germanium enrichment and leaching.

[0007] S200, Fuming Enrichment: After mixing the pretreated raw materials with the reducing agent, the mixture is sent to the fuming furnace for gradient heating and atmosphere control. The flue gas is collected to obtain indium-germanium zinc oxide dust. The mineralogical characteristics of the dust are verified and the raw material parameters of the leaching coupling control algorithm are fine-tuned.

[0008] S300, Coupled Acid Leaching: Indium-germanium-containing zinc oxide dust is mixed with zinc smelting circulating acid solution to form a slurry. The slurry is sent into a closed reaction vessel and the stirring and reaction temperature are controlled. System parameters are collected, and the simultaneous leaching efficiency of indium and germanium is calculated using the leaching coupling control algorithm. The amount of reagent added is dynamically adjusted to complete the acid leaching reaction and obtain the acid leaching slurry.

[0009] S400, gradient separation: solid-liquid separation is performed on the acid leaching slurry, and extraction back-extraction and tannic acid precipitation of germanium are carried out on the leachate in sequence. After the germanium precipitation, the solution is subjected to oxidation to remove iron and zinc electrowinning to achieve closed-loop circulation of materials throughout the process and complete the calibration of process parameters for the whole process recovery collaborative algorithm.

[0010] S500, intelligent control: It builds a full-process industrial production system and optimizes the material connection of each process. It calibrates relevant equipment parameters based on the full-process recycling collaborative algorithm and dynamically controls the process of each process. It conducts continuous operation tests of the production line, corrects the calibration parameters of the leaching coupling control algorithm and the full-process recycling collaborative algorithm, and optimizes the full-process process parameters. A threshold alarm mechanism is set in the entire production process, and the threshold judgment is triggered by the real-time collected process parameters.

[0011] Furthermore, the indium-germanium-zinc smelting raw material includes zinc leaching residue, secondary zinc oxide powder, and secondary indium-germanium-containing materials from zinc smelting. X-ray fluorescence spectroscopy and inductively coupled plasma atomic emission spectrometry are used for quantitative detection of the raw material composition. Scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction are used for mineralogical analysis of the raw material. Mechanical activation is achieved by continuous ball milling combined with grading sieves to control the particle size D90 ≤ 75 μm after grinding. Acid pre-leaching is carried out using 0.5-1 mol / L dilute sulfuric acid at a liquid-to-solid ratio of 3:1 and a temperature of 60°C. Calcium oxide is added at 2%-5% of the dry weight of the raw material and thoroughly mixed with the acid-preleached raw material.

[0012] Furthermore, the reducing agent is coke powder, and the amount of coke powder added is 5%-8% of the dry weight of the pretreated raw materials. After the raw materials and coke powder are batched, they are sent into the fuming furnace through a closed conveying device. The fuming furnace is heated in a gradient manner, first raising the temperature inside the furnace to 600°C, and then raising it to the reaction range of 950-1300°C. The CO concentration inside the furnace is controlled at 5%-20% by adjusting the ratio of primary air and secondary air volume and the feeding rate of reducing agent. The residence time of the material in the fuming furnace is controlled at 30-50 minutes. The indium-germanium-containing flue gas generated in the furnace is treated by waste heat recovery, cooling and dust collection to obtain indium-germanium-containing zinc oxide dust.

[0013] Furthermore, in the slurry preparation process, indium-germanium zinc oxide dust is mixed with zinc smelting circulating acid solution at a liquid-to-solid ratio of 5-8:1. The initial sulfuric acid concentration of the zinc smelting circulating acid solution is 1.0-2.0 mol / L. The sealed reactor is lined with titanium material. The stirring rate of the reaction system is controlled at 200-400 rpm, and the reaction system temperature is controlled at 75-90℃. The relevant parameters of the reaction system collected in real time include pH, ORP, chloride ion concentration, reaction temperature, and cumulative reaction time. Various reagents that are dynamically adjusted include concentrated sulfuric acid, in-situ oxidant, and complexing agent.

[0014] Furthermore, the in-situ oxidant is preferably selected from the high-iron silver leaching tailings produced by zinc smelting. The total iron content of the high-iron silver leaching tailings is ≥15%, and the Fe³+ content is ≥80%. The in-situ oxidant is added to the closed reactor in batches according to the real-time monitoring data of the reaction system ORP. When the ORP monitoring value does not reach the preset value and the suitable redox potential range for indium-germanium leaching is 600-900mV, compressed air or hydrogen peroxide is added to the reaction system as an auxiliary oxidant. The complexing agent is selected from industrial-grade sodium chloride or hydrochloric acid. The complexing agent is added to the closed reactor in batches according to the real-time monitoring data of the chloride ion concentration in the reaction system, and the chloride ion concentration in the reaction system is controlled to be maintained at 0.1-1.0mol / L.

[0015] Furthermore, the mathematical expression of the leaching coupling control algorithm is:

[0016]

[0017] in, is the simultaneous leaching efficiency of indium and germanium, and is the weighted average of the actual leaching rates of indium and germanium; The basic leaching efficiency of indium and germanium is given by the simultaneous leaching efficiency of indium and germanium under conventional acid leaching without multi-parameter coupling control, and is determined by the mineralogical characteristics of the raw materials. The pH adaptation correction coefficient characterizes the coupled regulatory effect of pH on the dissolution of indium and germanium. It is calibrated by the optimal pH window preset by the process. When the pH is within the optimal window [0.5, 2.0], =1.2-1.5; When pH deviates from the optimal window, kH decreases linearly with the degree of deviation; when pH < 0.5 or pH > 2.0, <0.8; The ORP (oxidation correction factor) characterizes the enhancing effect of the redox potential on the lattice disruption of indium-germanium minerals. It is determined by the optimal ORP window preset by the process. When the ORP is within the optimal window [600, 900] mV, =1.3-1.6; When ORP deviates from the optimal window, As the deviation index decreases, when ORP < 600mV, <0.7; The chloride ion complexation enhancement coefficient characterizes the interaction between chloride ions and chloride ions. The dissolution-promoting effect of forming soluble complexes is determined by the optimal chloride ion concentration window preset in the process. When the chloride ion concentration is within the optimal window [0.1, 1.0] mol / L, =1.1-1.4; When the chloride ion concentration exceeds the window, Maintain 1.0, with no enhancement effect and no negative interference; The actual reaction temperature of the acid leaching system is the real-time reaction temperature inside the sealed reactor. The actual reaction time for acid leaching is denoted as , and the cumulative reaction time is denoted as , from the time the slurry enters the reactor to the end of the acid leaching reaction. These are the thermodynamic characteristic constants of the raw materials, determined by the mineralogical characteristics of the pretreated raw materials.

[0018] Furthermore, the solid-liquid separation is carried out using a plate and frame filter press for constant pressure filtration. The lead-silver slag obtained by filtration is washed three times with clean water and then sent to the lead-silver recovery system. The washing water is returned to the slurry preparation process for reuse. For indium extraction, P204 is used as the extractant and sulfonated kerosene is used as the diluent to carry out 3-5 stages of countercurrent extraction. After washing, the indium-loaded organic phase is back-extracted in 2-3 stages with 5-6 mol / L hydrochloric acid to obtain an indium-rich solution. For germanium precipitation, the pH of the raffinate is first adjusted to 2.5-4.0, and then tannic acid is added at 25-30 times the amount of germanium. After stirring and reaction, centrifugation is used to obtain tannic germanium precipitate. After washing, the precipitate is calcined at 600-800℃. For iron removal and zinc electrowinning, compressed air is first introduced into the germanium-precipitated liquid, and then the pH of the solution is adjusted to 3.5-4.5. After filtering to remove iron, the solution is deeply purified and sent to the zinc electrowinning process. The waste liquid after electrowinning is returned to the slurry preparation process for reuse.

[0019] Furthermore, in the intelligent control system, a sealed buffer silo is set between the fuming furnace and the sealed reaction vessel, and an intermediate storage tank is set between the sealed reaction vessel and the indium extraction process. Material transportation between processes adopts a combination of pneumatic conveying and pipeline liquid flow conveying. After the industrial production system is built, continuous operation testing of the production line is carried out. The algorithm calibration parameters are corrected based on the actual production data of the continuous operation test. During the daily operation of the production line, the algorithm calibration parameters and process parameters of each process are continuously optimized through real-time collected production data. A threshold alarm mechanism is set in the entire production process. Threshold judgment is triggered by real-time collected process parameters to realize timely early warning of process abnormalities.

[0020] The threshold alarm mechanism is a multi-parameter hierarchical closed-loop alarm system covering the entire process. It pre-sets two levels of alarm thresholds for core process parameters and inter-process connection parameters of each process by combining algorithm calibration parameters and continuous operation test data of the production line. The second level is the process deviation warning threshold, which matches the upper and lower limits of the optimal process window. The first level is the safety interlock red line threshold, which corresponds to the critical limit of production and equipment operation. The core parameters cover the entire process of mineralization pretreatment, fumigation enrichment, coupled acid leaching, gradient separation, as well as the operating parameters of closed buffer silos, intermediate storage tanks, and material conveying. During production, parameters are collected in real time and multi-parameter coupling and linkage verification is performed to eliminate misjudgments due to single parameter fluctuations. When the second-level threshold is triggered, the process parameters are automatically corrected and an early warning is pushed. When the first-level threshold is triggered, the process interlock protection is immediately triggered and an emergency alarm is pushed. After the abnormality is handled, the data is fed back to the algorithm to continuously correct the algorithm calibration parameters and alarm thresholds, forming a closed-loop control of alarm-handling-optimization.

[0021] Furthermore, the mathematical expression of the end-to-end recycling collaborative algorithm is:

[0022]

[0023] in, To improve the overall recovery efficiency of indium and germanium throughout the entire process; The simultaneous leaching efficiency of indium and germanium is taken from the calculation results of the leaching coupling control algorithm; The efficiency of indium-germanium separation and enrichment is the combined separation efficiency of indium extraction and germanium precipitation by tannins, calibrated by industrial process parameters; It is a correction coefficient for the closed-loop material recovery rate, which characterizes the effect of the closed-loop process of waste liquid recycling, slag washing and reuse, and organic phase regeneration. It is determined by the material balance of the recycling process. It is a correction factor for equipment loss throughout the entire process, characterizing the material loss of equipment such as material conveying, filtration, and centrifugation. It is determined by equipment selection and process layout.

[0024] On the other hand, a system for multi-parameter coupled regulation of in-situ enhanced acid leaching simultaneous extraction of indium and germanium is provided, comprising:

[0025] Reaction Module: A closed reaction vessel lined with titanium, equipped with a controllable speed stirring device and a constant temperature control component. It serves as the core carrier for the acid leaching reaction of indium-germanium zinc oxide dust and zinc smelting circulating acid slurry. The vessel has a dosing end, a feeding end, and a discharging end, which are adapted to the dosing of reagents in the dosing module and the slurry transportation and discharge in the material module, ensuring that the acid leaching reaction is carried out under closed, constant temperature, and controllable stirring conditions.

[0026] Monitoring module: The detection terminals are all located inside the reaction vessel, including online sensors for pH, ORP, chloride ion concentration, and temperature, as well as a reaction time acquisition module. It collects all the parameters of the acid leaching system in real time, providing a precise and real-time data source for the coupled control of the entire system.

[0027] Dosing module: Connected to the dosing end of the reactor, it is equipped with independent dosing sub-modules for concentrated sulfuric acid, in-situ oxidant, complexing agent and auxiliary oxidant. Each sub-module is equipped with a designed quantity delivery component to add the corresponding agent into the reactor in batches, which is adapted to the dynamic control requirements of the acid leaching system parameters.

[0028] Material module: Includes slurry preparation and conveying unit and constant pressure filter separation unit, which can complete the preparation and quantitative supply of slurry, and at the same time perform solid-liquid separation on the slurry after acid leaching, complete the external delivery of lead-silver slag, reuse of washing water and export of filtrate, and build a material flow system for the entire acid leaching process;

[0029] Control module: It is a central controller with a built-in multi-parameter coupled control model, equipped with a data storage and parameter early warning module. Based on the real-time parameters collected by the monitoring module, it coordinates and controls the operation status of the reaction, dosing, and material modules, and records the entire process operation data simultaneously to achieve coordinated linkage and intelligent control of each module.

[0030] Compared with existing technologies, this AI platform's computing resource scheduling and management method and system have the following advantages:

[0031] I. This invention employs an in-situ enhanced acid leaching process design with multi-parameter coupling control, combined with a stepped raw material processing method of mineralization pretreatment and fuming enrichment. This allows for precise calibration and dynamic fine-tuning of basic raw material parameters, laying the foundation for simultaneous extraction of indium and germanium. In the coupled acid leaching stage, the leaching coupling control algorithm, combined with real-time acquisition of multi-dimensional system parameters, enables dynamic adjustment of reagent dosage. This breaks through the technical bottleneck of insufficient leaching of complex indium and germanium compounds in traditional acid leaching processes, achieving efficient simultaneous leaching of indium and germanium. In the gradient separation stage, the orderly connection of extraction back-extraction, precipitation for germanium extraction, and iron removal electrowinning achieves precise separation of indium and germanium from other valuable metals. Simultaneously, a system for recycling washing water and waste liquid is constructed, realizing a closed-loop circulation of materials. This improves the comprehensive utilization efficiency of rare and dispersed metals in zinc smelting byproducts, solving the industry pain points of difficulty in simultaneously recovering indium and germanium and resource waste in traditional processes.

[0032] II. This invention establishes a complete industrial production system and optimizes the material connection methods of each process. Relying on a full-process recycling collaborative algorithm, it completes the calibration of equipment parameters and dynamic control of each process. Combined with a threshold alarm mechanism, it realizes real-time monitoring and anomaly warning of the production process, ensuring the continuous and stable operation of the production line. Through continuous collection and analysis of production data, it continuously corrects and optimizes the calibration parameters of the algorithm and process parameters, realizing intelligent control of the entire process from raw material pretreatment to indium and germanium recovery. This promotes the upgrading of rare and dispersed metal extraction processes to automation and intelligence, while realizing the coordinated matching of fuming, acid leaching, and separation processes. It solves the problems of lagging process parameter control, poor production continuity, and difficulty in process scale-up in traditional processes. This helps the zinc smelting industry form a green and low-carbon circular economy model, improves the recycling capacity of strategic rare and dispersed metals, and promotes the transformation, upgrading, and high-quality development of the non-ferrous metals industry.

[0033] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0035] Figure 1 Flowchart of a method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium under multi-parameter coupled regulation;

[0036] Figure 2 A schematic diagram of data transmission for a method of in-situ enhanced acid leaching simultaneous extraction of indium and germanium under multi-parameter coupled regulation;

[0037] Figure 3 This is a distribution diagram showing the application fields of indium and germanium in this invention;

[0038] Figure 4 This is a process flow diagram of indium and germanium extraction and separation in the zinc smelting process of the present invention. Detailed Implementation

[0039] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0040] Example 1:

[0041] This embodiment uses zinc leaching residue generated during zinc hydrometallurgy as the core raw material for indium-germanium-containing zinc smelting. An industrial-scale experiment was conducted using a multi-parameter coupled control method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium. The zinc leaching residue used in the experiment was tested and found to have an initial indium grade of 0.012% and a germanium grade of 0.008%. The experiment scaled a single processing of 500 kg of raw material. The entire process strictly followed the technological flow of mineralization pretreatment, fumigation enrichment, coupled acid leaching, gradient separation, and intelligent control. Process parameters were precisely controlled at each stage, and leaching coupling control algorithms and full-process recovery collaborative algorithms were simultaneously used to achieve parameter calibration and dynamic control, ultimately achieving efficient simultaneous extraction of indium and germanium. Figure 1 As shown, the relevant experimental data and operational details are as follows.

[0042] In the mineralization pretreatment stage, X-ray fluorescence spectroscopy and inductively coupled plasma atomic emission spectrometry were used to conduct full-component quantitative analysis on 500 kg of zinc leaching residue to accurately obtain the content ratio of elements such as indium, germanium, zinc, iron, and silicon in the raw material. At the same time, scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction were used to conduct mineralogical analysis to clearly identify the mineral phase characteristics of indium and germanium in zinc leaching residue existing in the form of ferrates and silicates, providing accurate mineralogical basis for subsequent process adjustments. Based on the test and analysis results, the zinc leaching residue was subjected to mechanical activation, dilute sulfuric acid pre-leaching, and additive treatment in sequence. Mechanical activation was carried out by continuous ball milling and grading sieve. After grinding, the particle size of the raw material was controlled to be below 0.074 mm, accounting for 90%. This broke the encapsulation structure of silicates and iron oxides on indium and germanium minerals, allowing the indium and germanium minerals to be fully exposed, creating a better reaction interface for subsequent acid leaching. Dilute sulfuric acid pre-leaching was carried out by leaching with a low-concentration sulfuric acid solution to dissolve some of the easily soluble iron and calcium impurities in the raw material, reducing the formation of silica gel and impurity interference in subsequent processes. Calcium oxide was added at 3% of the dry weight of the zinc leaching residue. The calcium oxide was thoroughly mixed with the zinc leaching residue after acid pre-leaching. Calcium oxide can combine with silicon-like substances in the raw material to inhibit the formation of germanium-silicon complexes during subsequent fuming enrichment, reducing the ineffective loss of indium and germanium. After completing the above processing, based on the composition and mineralogical data of the raw materials, the basic parameters of the leaching coupling control algorithm are calibrated, establishing a basic database for the dynamic adjustment of parameters in subsequent coupled acid leaching. After this process, the exposure rate of indium and germanium minerals in zinc leaching residue is increased to over 85%.

[0043] In the fuming enrichment stage, the zinc leaching residue after mineralization pretreatment is mixed with reducing agent coke powder. The coke powder is added at a ratio of 6% of the dry weight of the raw materials. After mixing, the material is sent into the fuming furnace via a closed conveyor system. The closed conveyor system prevents oxidation of the material during transportation and ensures a reducing atmosphere for the fuming reaction. The fuming furnace uses a gradient heating mode. The furnace temperature is first gradually increased from room temperature to 600℃ for preliminary preheating, and then increased to the fuming reaction zone of 1250℃ at a heating rate of 5℃ / min. The gradient heating prevents the raw materials from agglomerating due to a sudden temperature increase, ensures uniform heating of the material, and improves the sufficiency of the fuming reaction. By adjusting the airflow ratio of primary and secondary air and the feeding rate of coke powder, the CO concentration in the furnace is precisely controlled at around 12%. This suitable CO concentration provides a stable reducing environment for the fuming reaction, promoting the conversion of indium and germanium from the solid phase to the gas phase. Simultaneously, the residence time of the material in the fuming furnace is strictly controlled to 40 minutes, ensuring sufficient volatilization of indium and germanium while avoiding over-calcination. The indium- and germanium-containing flue gas generated in the furnace first recovers heat through a waste heat recovery device, achieving energy recycling. Then, the flue gas temperature is reduced to below 200℃ by a cooling device. Finally, it undergoes efficient dust collection to obtain indium- and germanium-containing zinc oxide dust. Testing shows that the indium volatilization rate reaches 82% and the germanium volatilization rate reaches 70% in this stage. The indium grade in the indium- and germanium-containing zinc oxide dust is increased to 0.18% and the germanium grade to 0.096%, which are 15 times and 12 times that of the original zinc leaching residue, respectively. The mineralogical characteristics of the flue dust were re-verified, and the raw material parameters of the leaching coupling control algorithm were fine-tuned based on the verification results to ensure that the algorithm parameters were highly compatible with the mineralogical characteristics of the flue dust, thereby improving the accuracy of subsequent coupled acid leaching algorithm calculations.

[0044] In the coupled acid leaching process, indium-germanium zinc oxide fume and circulating acid from zinc smelting are mixed into a slurry with a liquid-to-solid ratio controlled at 6:1. Thorough stirring during slurry preparation ensures uniform mixing of the fume and acid, forming a highly fluid slurry that improves mass transfer efficiency in subsequent acid leaching reactions. The mixed slurry is then fed into a titanium-lined, sealed reactor. The titanium lining effectively resists acid corrosion, extending the reactor's lifespan, while the sealed environment prevents acid mist escape, ensuring production safety and reducing acid loss. The stirring rate within the reactor is controlled at 300 rpm, and the reaction system temperature is stabilized at 80°C. Appropriate stirring rate and temperature accelerate the reaction rate between indium-germanium minerals and acid, preventing localized overheating or material deposition. Online sensors installed within the reactor collect real-time data on parameters such as pH, ORP, chloride ion concentration, reaction temperature, and cumulative reaction time at a frequency of once per minute, ensuring real-time and continuous data transmission. The collected parameter data is transmitted in real time to the leaching coupling control algorithm. The mathematical expression of the leaching coupling control algorithm is:

[0045]

[0046] in, To improve the efficiency of simultaneous leaching of indium and germanium; For indium-germanium base leaching efficiency; This is a pH adaptation correction factor; This is the ORP oxidation correction factor; The chloride ion complexation enhancement coefficient; This refers to the actual reaction temperature of the acid leaching system. This refers to the actual reaction time of the acid leaching process; Using the thermodynamic characteristic constant of the raw materials, the algorithm was used to calculate the simultaneous leaching efficiency of indium and germanium. The dosage of reagents was dynamically adjusted based on the calculation results and parameter changes. Concentrated sulfuric acid, in-situ oxidant, and complexing agent were added to the reaction system in batches. The in-situ oxidant was selected from high-iron silver tailings produced in zinc smelting, and its dosage was adjusted gradually according to the redox potential monitoring data of the reaction system. If the redox potential monitoring value did not reach the suitable range for indium and germanium leaching, compressed air was added to the reaction system as an auxiliary oxidant to supplement the oxidizing atmosphere and promote the oxidation and dissolution of indium and germanium. Industrial-grade sodium chloride was selected as the complexing agent and its dosage was added according to the chloride ion concentration monitoring data of the reaction system to control the chloride ion concentration within a suitable range. Chloride ions can form complexes with indium and germanium ions, increasing the solubility of indium and germanium in the acid solution and reducing precipitation loss. The entire acid leaching reaction lasted 90 minutes, and the resulting acid-leached slurry was tested. The simultaneous leaching efficiencies of indium and germanium in this step reached 90% and 86%, respectively, achieving highly efficient leaching of indium and germanium.

[0047] Gradient separation process, such as Figure 4As shown, constant pressure filtration was used to separate the acid-leached slurry into solids and liquids. The filtration pressure was controlled at 0.8 MPa. Constant pressure filtration improves the efficiency of solid-liquid separation, ensures that the moisture content of the filter cake is controlled below 25%, and reduces the loss of valuable metals with the filter cake. The lead-silver slag obtained from the filtration was washed with clean water and then sent to the lead-silver recovery process. The washing water was returned to the slurry preparation process for reuse, realizing a closed-loop water resource cycle and reducing the consumption of fresh water. The residual indium and germanium in the lead-silver slag were both controlled below 3% after testing. The leachate obtained from solid-liquid separation was subjected to extraction and back-extraction, followed by tannic acid precipitation of germanium. For indium extraction, a five-stage countercurrent extraction was carried out using an extractant and diluent at a volume ratio of 1:4. Multi-stage countercurrent extraction can improve the extraction efficiency of indium and reduce the loss of indium with the raffinate. After the indium-loaded organic phase was washed with 10% dilute sulfuric acid to remove impurities, a two-stage countercurrent back-extraction was carried out using a back-extraction agent to obtain an indium-rich solution. The indium extraction rate reached 96%, the back-extraction rate reached 98%, and the indium grade in the indium-rich solution was increased to over 50 g / L. For germanium precipitation, the pH of the raffinate is first adjusted to 3.0 with an alkaline solution. Then, tannic acid is added as a precipitant at a ratio of 28 times the amount of germanium. After stirring and reacting for 30 minutes, germanium-containing precipitate is obtained by centrifugation. The precipitate is washed multiple times with water to remove soluble impurities and then calcined at 600℃. Calcination removes organic impurities from the precipitate and improves the purity of the germanium concentrate. The precipitate precipitation rate of germanium by tannic acid reaches 95%, and the grade of the germanium concentrate obtained after calcination is over 25%. Compressed air is introduced into the germanium-precipitated solution as an oxidizing gas to oxidize and remove iron, converting ferrous iron to ferric iron. The pH of the solution is then adjusted to 4.0, causing the ferric iron to precipitate as ferric hydroxide. Iron slag is removed by filtration. After iron removal, the solution undergoes deep purification to remove trace amounts of lead, copper, and other impurities before being sent to the zinc electrowinning process. The waste liquid after electrowinning is returned to the slurry preparation process for reuse, achieving acid recycling. Testing shows that the zinc recovery rate in this stage reaches 96.5%, and the iron removal rate reaches over 99%. Throughout the gradient separation process, based on the process data and material recovery rates of each stage, the process parameters of the full-process recovery collaborative algorithm are calibrated, establishing a parameter basis for subsequent dynamic control of the entire process.

[0048] In the intelligent control phase, based on the process data from the aforementioned experimental phases, a full-process industrial production system adapted to zinc leaching residue raw materials was established. This system comprehensively optimized the material connection rhythm of each process, including mineralization pretreatment, fuming enrichment, coupled acid leaching, and gradient separation. A sealed buffer silo was installed between the fuming furnace and the sealed reactor to effectively buffer the material transport rhythm of fuming enrichment and coupled acid leaching, preventing material interruptions in the coupled acid leaching process due to fluctuations in fuming furnace output. An intermediate storage tank was installed between the sealed reactor and the indium extraction process to ensure a stable slurry supply for the indium extraction process. Material transport between processes combined pneumatic conveying and pipelined liquid flow conveying. Solid materials were transported using pneumatic conveying, which is highly efficient and leaves no residue, while liquid materials were transported using pipelined liquid flow conveying, achieving continuous material transport. The relevant operating parameters of each process's equipment were calibrated based on a full-process recycling collaborative algorithm. The mathematical expression of the full-process recycling collaborative algorithm is as follows:

[0049]

[0050] in, To improve the overall recovery efficiency of indium and germanium throughout the entire process; To improve the efficiency of simultaneous leaching of indium and germanium; To improve the efficiency of indium-germanium separation and enrichment; This is a correction factor for the closed-loop material recovery rate. This algorithm serves as a correction coefficient for equipment losses throughout the entire process and dynamically manages the process conditions of each step, enabling coordinated adjustment of parameters across all steps. When a parameter in a particular step fluctuates, the algorithm automatically adjusts the process parameters of related steps to ensure the stability of the entire process. After the industrial production system is established, a 72-hour continuous operation test of the production line is conducted. During the test, process parameters and material recovery rate data for each step are collected in real time. Based on the actual production data obtained from the test, the calibration parameters of the leaching coupling control algorithm and the whole-process recovery coordination algorithm are precisely corrected. At the same time, the process parameters of the entire process are optimized to ensure a high degree of compatibility between the algorithm and the process. A threshold alarm mechanism is set up throughout the entire production process. Reasonable threshold ranges are set for key process parameters such as temperature, pH, ORP, and flow rate. Threshold judgments are triggered by the real-time collected process parameters. When a parameter exceeds the threshold range, the system automatically issues an alarm signal to remind staff to handle it in time and avoid abnormal parameters leading to decreased production efficiency or fluctuations in product quality. After 72 hours of continuous operation testing, the production system operated stably, with fluctuations in key process parameters controlled within 5%. Ultimately, the overall recovery rate of indium reached over 80%, the overall recovery rate of germanium reached over 65%, and the overall recovery rate of zinc reached 96.5%, achieving efficient and comprehensive recovery of indium, germanium, and zinc.

[0051] This embodiment uses zinc leaching residue as raw material and employs a multi-parameter coupled control method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium. Mineralization pretreatment breaks down the mineral encapsulation structure of indium and germanium, increasing the mineral exposure rate to over 85%, laying the foundation for subsequent processes. Fumigation enrichment, through gradient heating and atmosphere control, achieves a volatilization rate of 82% for indium and 70% for germanium, significantly improving the indium and germanium grades. Coupled acid leaching relies on a leaching coupling control algorithm for dynamic parameter adjustment, achieving a simultaneous leaching efficiency of 90% for indium and 86% for germanium. Gradient separation, through multi-stage extraction and tannic acid precipitation of germanium, achieves efficient separation of indium and germanium, with a zinc recovery rate of 96.5%. The industrial system built with intelligent control, after 72 hours of continuous operation testing, exhibits minimal parameter fluctuations, ultimately achieving a comprehensive indium recovery rate of over 80% and a germanium recovery rate of over 65%, successfully realizing the efficient comprehensive recovery of indium, germanium, and zinc from zinc leaching residue and providing a feasible industrial path for the resource utilization of zinc leaching residue.

[0052] Example 2:

[0053] This embodiment uses zinc oxide powder, a secondary resource in zinc smelting, as the core raw material for indium-germanium zinc smelting. This raw material is characterized by high fluorine and chlorine content and uneven indium-germanium distribution. Initial testing showed an indium grade of 0.015%, a germanium grade of 0.010%, a fluorine content of 0.3%, and a chlorine content of 0.4%. An industrial-scale trial was conducted using a multi-parameter coupled control method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium. The trial scale was 500 kg of raw material processed per batch. The entire process followed a flow of mineralization pretreatment, fumigation enrichment, coupled acid leaching, gradient separation, and intelligent control. Process details were optimized based on the characteristics of the zinc oxide powder raw material. Simultaneously, a leaching coupling control algorithm and a full-process recovery collaborative algorithm were used to achieve precise parameter calibration and dynamic control, effectively solving the interference problem of fluorine and chlorine impurities and achieving efficient simultaneous extraction of indium and germanium. Figure 2 As shown, the relevant experimental data and operational details are as follows.

[0054] In the mineralization pretreatment stage, X-ray fluorescence spectroscopy and inductively coupled plasma atomic emission spectrometry were used to conduct full-component quantitative analysis on 500 kg of zinc oxide powder to accurately obtain the content ratio of elements such as indium, germanium, zinc, fluorine, chlorine, and silicon in the raw material. At the same time, scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction were used to conduct mineralogical analysis, which clarified that indium and germanium in zinc oxide powder mainly exist in the form of oxides and a small amount of germanate, and that fluorine and chlorine mainly exist in the form of soluble salts and adsorbed states. This mineral phase characteristic provides accurate mineralogical and compositional basis for subsequent process adjustments. Based on the test and analysis results, the zinc oxide powder underwent mechanical activation, dilute sulfuric acid pre-leaching, and additive treatment in sequence. Mechanical activation was carried out using a continuous ball mill and sieving with a classifying sieve. After grinding, the particle size of the raw material was controlled to be below 0.074 mm, accounting for 88%. This broke the agglomeration structure of indium and germanium minerals in the zinc oxide powder, allowing the indium and germanium minerals to be fully exposed. At the same time, it destroyed the adsorption and binding state of fluorine and chlorine with the minerals, creating better conditions for subsequent fluorine and chlorine removal and acid leaching reactions. Dilute sulfuric acid pre-leaching was carried out using a low-concentration sulfuric acid solution. While dissolving some easily soluble impurities, it also dissolved some soluble fluorine and chlorine salts in the raw material into the solution, achieving preliminary removal of fluorine and chlorine and reducing the interference of fluorine and chlorine on equipment and reactions in subsequent processes. The test results showed that the preliminary fluorine removal rate reached 40% and the preliminary chlorine removal rate reached 45% in this step. Additives include calcium oxide at 4% of the dry weight of the zinc oxide powder. The calcium oxide is thoroughly mixed with the acid-pre-leached zinc oxide powder. Calcium oxide can combine with silicon-like substances in the raw material to form stable calcium silicate, inhibiting the formation of germanium-silicon complexes during subsequent fuming enrichment and acid leaching. Simultaneously, it can combine with some fluoride ions to form calcium fluoride precipitate, further reducing interference from fluoride impurities. After the above treatment, based on the raw material composition, mineralogical data, and fluoride / chlorine removal status, the basic parameters of the leaching coupling control algorithm are calibrated. This establishes a basic database tailored to the raw material characteristics for subsequent dynamic adjustment of parameters in coupled acid leaching. After this step, the exposure rate of indium and germanium minerals in the zinc oxide powder increases to over 83%.

[0055] In the fuming enrichment stage, zinc oxide powder that has undergone mineralization pretreatment and preliminary fluorine and chlorine removal is mixed with reducing agent coke powder. The coke powder is added at a ratio of 7% of the dry weight of the raw materials. After mixing, the material is sent into the fuming furnace via a closed conveyor. The closed conveyor prevents the material from oxidizing due to contact with air during transportation, ensuring a reducing atmosphere for the fuming reaction, and reducing the escape of fluorine and chlorine impurities during transportation, thus minimizing the impact on the production environment. The fuming furnace uses a gradient heating mode. The furnace temperature is first gradually increased from room temperature to 550℃ for preliminary preheating, and then increased to the fuming reaction zone of 1200℃ at a heating rate of 4℃ / min. The gradient heating prevents the zinc oxide powder from agglomerating due to a sudden temperature increase, ensuring uniform heating of the material, and reducing the corrosion of the equipment caused by the rapid escape of fluorine and chlorine impurities due to high temperature. By adjusting the air volume ratio of primary and secondary air and the feeding rate of coke powder, the CO concentration in the furnace is precisely controlled at around 10%. The appropriate CO concentration provides a stable reducing environment for the fuming reaction, promoting the transformation of indium and germanium from the solid phase to the gas phase. At the same time, the residence time of the material in the fuming furnace is strictly controlled to 45 minutes to ensure that indium and germanium are fully volatilized while reducing the excessive volatilization of fluorine and chlorine impurities, and reducing the interference of fluorine and chlorine in the subsequent dust collection and acid leaching processes. The indium-germanium-containing flue gas generated in the furnace first recovers heat through a waste heat recovery device to achieve energy recycling. Then, it is cooled to below 180℃ by a cooling device, and finally, it undergoes efficient dust collection to obtain indium-germanium-containing zinc oxide dust. Testing shows that the indium volatilization rate in this stage reaches 80%, and the germanium volatilization rate reaches 68%. The indium grade in the indium-germanium-containing zinc oxide dust is increased to 0.195%, and the germanium grade to 0.10%, which are 13 times and 10 times higher than the original zinc oxide powder, respectively. Furthermore, the fluorine content in the dust is reduced to 0.18%, and the chlorine content to 0.22%, indicating further removal of fluorine and chlorine. The mineralogical characteristics of this dust are then re-examined, focusing on the occurrence forms of indium and germanium and the residual states of fluorine and chlorine. Based on the re-examination results, the raw material parameters of the leaching coupling control algorithm are fine-tuned to ensure a high degree of compatibility between the algorithm parameters and the characteristics of the dust, thereby improving the accuracy of subsequent coupled acid leaching algorithm calculations and the precision of parameter control.

[0056] In the coupled acid leaching process, indium-germanium zinc oxide dust and circulating acid from zinc smelting are mixed into a slurry with a liquid-to-solid ratio controlled at 7:1. Thorough stirring during slurry preparation ensures uniform mixing of the dust and acid, forming a highly fluid slurry. To address the presence of residual fluoride and chlorine in the dust, the stirring rate is appropriately increased during slurry preparation to reduce the deposition of fluoride and chlorine salts in the slurry and improve the mass transfer efficiency of the subsequent acid leaching reaction. The mixed slurry is then fed into a titanium-lined, sealed reactor. The titanium lining effectively resists the dual corrosion of acid and fluoride / chlorine impurities, extending the reactor's service life. The sealed environment prevents the escape of acid mist and fluoride / chlorine gases, ensuring production safety while reducing acid loss. The stirring rate within the reactor is controlled at 350 rpm, and the reaction system temperature is maintained at 75°C. Appropriate stirring rate and temperature accelerate the reaction rate between indium-germanium minerals and acid while preventing excessive fluoride / chlorine gas escape due to high temperatures, which could exacerbate equipment corrosion. Online sensors installed inside the reactor are used to collect relevant parameters of the reaction system in real time, such as pH, ORP, chloride ion concentration, reaction temperature, and cumulative reaction time. The parameter collection frequency is once per minute to ensure the real-time and continuous nature of the parameter data. In view of the characteristics of fluorine and chlorine residues, the focus is on monitoring changes in chloride ion concentration and adjusting the dosage of complexing agent in a timely manner. The collected parameter data is transmitted in real time to the leaching coupling control algorithm. This algorithm is used to calculate the simultaneous leaching efficiency of indium and germanium, and the dosage of reagents is dynamically adjusted according to the calculation results and parameter changes. Concentrated sulfuric acid, in-situ oxidant, and complexing agent are added to the reaction system in batches. The in-situ oxidant is selected from the high-iron silver tailings produced by zinc smelting. It is added according to the redox potential monitoring data of the reaction system, and the dosage is gradually adjusted according to the potential changes. If the redox potential monitoring value does not reach the suitable range for indium and germanium leaching, compressed air is added to the reaction system as an auxiliary oxidant to supplement the oxidizing atmosphere of the system and promote the oxidation and dissolution of indium and germanium. The complexing agent is industrial-grade sodium chloride, which is added according to the chloride ion concentration monitoring data of the reaction system to control the chloride ion concentration in the system within a suitable range. Chloride ions can form complexes with indium and germanium ions, increasing the solubility of indium and germanium in acid. At the same time, it can combine with fluoride ions to form complexes, reducing the interference of fluoride ions on the leaching of indium and germanium. The entire acid leaching reaction lasted 100 minutes, and the resulting acid leaching slurry was tested. The simultaneous leaching efficiency of indium and germanium in this step reached 89% and 85%, respectively. Fluorine and chlorine were further dissolved into the solution, creating conditions for deep removal in subsequent separation steps.

[0057] In the gradient separation stage, the acid-leached slurry is subjected to constant-pressure filtration using a filter press to achieve solid-liquid separation. The filtration pressure is controlled at 0.9 MPa. Constant-pressure filtration improves the efficiency of solid-liquid separation, ensures that the moisture content of the filter cake is controlled below 24%, and reduces the loss of valuable metals with the filter cake. Considering the fluorine and chlorine content in the slurry, the filter cloth of the filter press is made of corrosion-resistant material to extend its service life. The lead-silver slag obtained from the filter press is washed multiple times with clean water and then sent to the lead-silver recovery process. The washing water is returned to the slurry preparation process for reuse, realizing a closed-loop water resource cycle and reducing the consumption of fresh water. The residual indium and germanium in the lead-silver slag are controlled below 3.5% after testing. The leachate obtained from solid-liquid separation was subjected to extraction-back-extraction and tannic acid precipitation of germanium in sequence. For indium extraction, a four-stage countercurrent extraction was carried out using an extractant and a diluent at a volume ratio of 1:5. Considering the presence of small amounts of fluorine and chlorine in the leachate, the number of extraction stages was appropriately increased to improve the extraction efficiency of indium and reduce the interference of fluorine and chlorine on the extraction. After the indium-loaded organic phase was washed with water to remove impurities such as fluorine and chlorine, a three-stage countercurrent back-extraction was carried out using a back-extraction agent to obtain an indium-rich solution. The results showed that the indium extraction rate reached 95%, the back-extraction rate reached 97%, the indium grade in the indium-rich solution was increased to above 48 g / L, and the fluorine and chlorine content was reduced to an extremely low level. For germanium precipitation, the pH of the raffinate was first adjusted to 2.8 with an alkaline solution. Then, tannic acid was added as a precipitant at a ratio of 26 times the amount of germanium. After stirring for 35 minutes, the germanium-containing precipitate was obtained by centrifugation. Considering the trace amounts of fluorine and chlorine still present in the raffinate, the stirring rate was appropriately increased during the stirring process to ensure that the tannic acid and germanium ions reacted fully. After the precipitate was washed multiple times with water to remove soluble fluorine, chlorine, and impurities, it was calcined at 650℃. Calcination can remove organic impurities and some bound fluorine and chlorine from the precipitate, thereby improving the purity of the germanium concentrate. The precipitation rate of germanium by tannic acid reached 97%, and the grade of the germanium concentrate obtained after calcination reached over 24%. Compressed air is introduced into the germanium-precipitated solution as an oxidizing gas to oxidize and remove iron, converting ferrous iron to ferric iron. The pH of the solution is then adjusted to 4.2, causing the ferric iron to form ferric hydroxide precipitate. This precipitate adsorbs some fluoride ions, achieving deep fluoride removal. Iron slag is removed by filtration, and the solution is then further purified using ion exchange to remove residual chloride ions and trace amounts of lead, copper, and other impurities. The chloride removal rate reaches over 99%, and the fluoride removal rate reaches over 98%. The purified solution is then sent to the zinc electrowinning process for zinc electrowinning. The waste liquid after electrowinning is returned to the slurry preparation process for reuse, achieving acid recycling. Testing shows that the zinc recovery rate in this stage reaches 96.5%, and the iron removal rate reaches over 99%. Throughout the gradient separation process, based on the process data, material recovery rate, and fluoride and chloride removal effects of each stage, the process parameters of the full-process recovery collaborative algorithm are calibrated, establishing a parameter basis that fits the characteristics of the zinc oxide powder raw material for subsequent dynamic control of the entire process.

[0058] In the intelligent control phase, based on the process data and fluoride / chlorine removal effects from the aforementioned experimental phases, a full-process industrial production system adapted to zinc oxide powder raw materials was established. The material connection rhythm of each process—mineralization pretreatment, fumigation enrichment, coupled acid leaching, and gradient separation—was comprehensively optimized. Given the high fluoride / chlorine content of zinc oxide powder, material buffering and impurity pretreatment steps were added between each process. A sealed buffer silo was installed between the fumigation furnace and the sealed reactor to buffer the material transport rhythm of fumigation enrichment and coupled acid leaching, preventing material interruption in the coupled acid leaching process due to fluctuations in the fumigation furnace output. Simultaneously, the buffer silo was equipped with a tail gas absorption device to absorb any small amounts of fluoride / chlorine gas that escaped. An intermediate storage tank was installed between the sealed reactor and the indium extraction process to ensure a stable slurry supply for the indium extraction process. The storage tank was equipped with a stirring device to prevent the deposition of fluoride / chlorine salts in the slurry. Material conveying between processes employs a combination of pneumatic conveying and pipelined liquid flow conveying. Solid materials are conveyed pneumatically using corrosion-resistant pipelines, while liquid materials are conveyed via pipelined liquid flow conveying. Pipeline cleaning devices are installed to regularly clean the pipelines and prevent the accumulation and blockage of fluoride and chloride salts. A full-process recovery collaborative algorithm is used to calibrate the relevant operating parameters of equipment in each process, with a focus on calibrating parameters related to fluoride and chloride removal and indium-germanium leaching. This algorithm dynamically manages the process conditions of each process, enabling coordinated adjustment of parameters. When fluoride and chloride concentrations fluctuate, the algorithm automatically adjusts the process parameters of the acid leaching and purification stages to ensure effective fluoride and chloride removal and efficient indium-germanium leaching. After the industrial production system was established, a 72-hour continuous production line test was conducted. During the test, real-time data on process parameters, material recovery rates, and fluoride and chloride removal rates for each process were collected. Based on the actual production data obtained from the test, the calibration parameters of the leaching coupling control algorithm and the full-process recovery collaborative algorithm were precisely corrected, and the process parameters of the entire process were optimized to ensure a high degree of compatibility between the algorithm and the process. A multi-dimensional threshold alarm mechanism is implemented throughout the entire production process. Reasonable threshold ranges are set for key process parameters such as temperature, pH, ORP, flow rate, and fluoride / chlorine concentration. Threshold judgments are triggered by real-time collected process parameters. When parameters exceed the threshold range, the system automatically issues an alarm signal, reminding staff to handle the situation promptly and preventing parameter anomalies from causing decreased production efficiency, equipment corrosion, or product quality fluctuations. After 72 hours of continuous operation testing, the production system operated stably, with fluctuations in key process parameters controlled within 6%. The final fluoride / chlorine removal rates reached over 98% and 99%, respectively, effectively solving the interference problem caused by fluoride / chlorine impurities. Ultimately, the overall indium recovery rate remained stable above 80%, the germanium recovery rate above 65%, and the zinc recovery rate reached 96.5%, achieving efficient comprehensive recovery of indium, germanium, and zinc, as well as deep removal of fluoride / chlorine.

[0059] This embodiment uses zinc oxide powder with high fluoride and chlorine content as raw material. By optimizing process details based on the raw material characteristics, the method of this invention achieves efficient extraction of indium and germanium and deep removal of fluoride and chlorine. Mineralization pretreatment achieves initial removal of fluoride and chlorine, with indium and germanium mineral exposure exceeding 83%. Fumigation enrichment precisely controls the atmosphere and temperature, resulting in indium and germanium volatilization rates of 80% and 68%, respectively, while simultaneously reducing fluoride and chlorine volatilization. Coupled acid leaching, relying on a leaching coupling control algorithm, achieves further dissolution of fluoride and chlorine at indium and germanium leaching efficiencies of 89% and 85%. Gradient separation, through extraction, germanium precipitation, and deep purification, achieves deep removal of fluoride and chlorine, with an indium extraction rate of 95% and a germanium precipitation rate of 97%. The intelligent control system, after 72 hours of continuous operation, maintains stable parameters, with fluoride and chlorine removal rates exceeding 98% and indium and germanium comprehensive recovery rates consistently above 80% and 65%, respectively. This solves the industry problem of fluoride and chlorine interference in zinc oxide powder and provides an industrial demonstration for the high-value utilization of secondary zinc resources.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium under multi-parameter coupled regulation, characterized in that, The method includes: S100, mineralization pretreatment: quantitative analysis and mineralogical analysis of the components of indium, germanium and zinc smelting raw materials are carried out. Based on the analysis results, the raw materials are mechanically activated, pre-leached with dilute sulfuric acid and treated with additives in sequence. The basic parameters of the raw materials are calibrated for the leaching coupling control algorithm. S200, Fuming Enrichment: After mixing the pretreated raw materials with the reducing agent, the mixture is sent to the fuming furnace for gradient heating and atmosphere control. The flue gas is collected to obtain indium-germanium zinc oxide dust. The mineralogical characteristics of the dust are verified and the raw material parameters of the leaching coupling control algorithm are fine-tuned. S300, Coupled Acid Leaching: Indium-germanium-containing zinc oxide dust is mixed with zinc smelting circulating acid solution to form a slurry. The slurry is sent into a closed reaction vessel and the stirring and reaction temperature are controlled. System parameters are collected, and the simultaneous leaching efficiency of indium and germanium is calculated using the leaching coupling control algorithm. The amount of reagent added is dynamically adjusted to complete the acid leaching reaction and obtain the acid leaching slurry. S400, gradient separation: solid-liquid separation is performed on the acid leaching slurry, and extraction back-extraction and tannic acid precipitation of germanium are carried out on the leachate in sequence. After the germanium precipitation, the solution is subjected to oxidation to remove iron and zinc electrowinning. The process parameters of the whole process recovery collaborative algorithm are calibrated. S500, Intelligent Control: It establishes a full-process industrialized production system and optimizes the material connection of each process. It calibrates relevant equipment parameters based on the full-process recycling collaborative algorithm and dynamically controls the process of each process. It conducts continuous operation tests of the production line, corrects the calibration parameters of the leaching coupling control algorithm and the full-process recycling collaborative algorithm, and optimizes the process parameters of the entire process.

2. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S100, the indium-germanium-zinc smelting raw material includes zinc leaching residue, secondary zinc oxide powder, and secondary indium-germanium-containing materials from zinc smelting. X-ray fluorescence spectroscopy and inductively coupled plasma atomic emission spectrometry are used for quantitative detection of the raw material composition. Scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction are used for mineralogical analysis of the raw material. Mechanical activation is carried out by continuous ball milling and sieving with a classifying sieve. Calcium oxide is added at 2%-5% of the dry weight of the raw material and thoroughly mixed with the raw material after acid pre-leaching.

3. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S200, the reducing agent is coke powder. The raw materials and coke powder are fed into the fuming furnace through a closed conveying device after being batched. The fuming furnace adopts a gradient heating mode to heat the furnace. First, the temperature inside the furnace is initially increased, and then the temperature is increased to the fuming reaction zone. The CO concentration inside the furnace is controlled by adjusting the air volume ratio of primary air and secondary air and the feeding rate of the reducing agent. The residence time of the material in the fuming furnace is controlled. The indium-germanium-containing flue gas generated in the furnace is treated by waste heat recovery, cooling and dust collection to obtain indium-germanium-containing zinc oxide dust.

4. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S300, the slurry preparation process mixes indium-germanium zinc oxide dust with zinc smelting circulating acid. The mixed slurry is then fed into a closed reactor lined with titanium. The stirring and temperature of the reaction system are controlled, and relevant parameters of the reaction system, including pH, ORP, chloride ion concentration, reaction temperature, and cumulative reaction time, are collected in real time. Based on the changes in parameters, concentrated sulfuric acid, in-situ oxidant, complexing agent, and other reagents are dynamically added to the reaction system.

5. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 4, characterized in that, In step S300, the in-situ oxidant is preferably high-iron silver tailings produced by zinc smelting. The in-situ oxidant is added to the closed reactor in batches according to the redox potential monitoring data of the reaction system. When the redox potential monitoring value does not reach the redox potential range suitable for indium-germanium leaching, compressed air is added to the reaction system as an auxiliary oxidant. The complexing agent is industrial-grade sodium chloride. The complexing agent is added to the closed reactor in batches according to the chloride ion concentration monitoring data of the reaction system to control the chloride ion concentration in the reaction system.

6. The method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium by multi-parameter coupling regulation according to claim 1, characterized in that, In step S300, the mathematical expression of the leaching coupling control algorithm is: in, To improve the efficiency of simultaneous leaching of indium and germanium; For indium-germanium base leaching efficiency; This is a pH adaptation correction factor; This is the ORP oxidation correction factor; The chloride ion complexation enhancement coefficient; This refers to the actual reaction temperature of the acid leaching system. This refers to the actual reaction time of the acid leaching process; is the characteristic constant of the thermodynamics of the raw material.

7. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S400, the solid-liquid separation is performed using a constant pressure filtration device. The lead-silver slag obtained by filtration is washed with clean water and then sent to the lead-silver recovery process. The washing water is returned to the slurry preparation process for reuse. Indium extraction is performed using an extractant and a diluent for multi-stage countercurrent extraction. The indium-loaded organic phase is washed and then subjected to 2-3 stages of countercurrent back-extraction with a back-extraction agent to obtain an indium-rich solution. For germanium precipitation, the pH of the raffinate is first adjusted, then a precipitant is added. After stirring and reaction, germanium-containing precipitate is separated. The precipitate is washed and then subjected to high-temperature calcination. For iron removal and zinc electrowinning, oxidizing gas is first introduced into the germanium-precipitated liquid, then the pH of the solution is adjusted. After iron removal by filtration, the solution is deeply purified and sent to the zinc electrowinning process. The waste liquid after electrowinning is returned to the slurry preparation process for reuse.

8. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S500, the intelligent control system includes a sealed buffer silo between the fuming furnace and the sealed reactor, and an intermediate storage tank between the sealed reactor and the indium extraction process. Material transport between processes is achieved by a combination of pneumatic conveying and pipelined liquid flow transport. After the industrial production system is established, continuous operation testing of the production line is conducted. The algorithm calibration parameters are corrected based on the actual production data from the continuous operation test. During daily operation of the production line, the algorithm calibration parameters and process parameters of each process are continuously optimized by real-time collected production data. A threshold alarm mechanism is set up throughout the entire production process, and threshold judgment is triggered by real-time collected process parameters.

9. The method for simultaneous extraction of indium and germanium by in-situ enhanced acid leaching under multi-parameter coupling control according to claim 1, characterized in that, In step S500, the mathematical expression of the full-process recycling collaborative algorithm is: in, To improve the overall recovery efficiency of indium and germanium throughout the entire process; To improve the efficiency of simultaneous leaching of indium and germanium; To improve the efficiency of indium-germanium separation and enrichment; This is a correction factor for the closed-loop material recovery rate. This is the correction factor for equipment loss throughout the entire process.

10. A system for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium under multi-parameter coupling regulation, the system being applicable to the method for in-situ enhanced acid leaching and simultaneous extraction of indium and germanium under multi-parameter coupling regulation as described in any one of claims 1-9, characterized in that, The system includes: Reaction Module: A closed reaction vessel lined with titanium. The vessel body is equipped with a controllable speed stirring device and a constant temperature control component. It serves as the core carrier for the acid leaching reaction of indium-germanium zinc oxide dust and zinc smelting circulating acid slurry. The vessel body has a dosing end, a feeding end and a discharging end, which are adapted to the dosing of reagents in the dosing module and the slurry transportation and slurry discharge in the material module. Monitoring module: The detection terminals are all located inside the reaction vessel, including online sensors for pH, ORP, chloride ion concentration, and temperature, as well as a reaction time acquisition module, to collect all the parameters of the acid leaching system in real time; Dosing module: Connected to the dosing end of the reactor, it is equipped with independent dosing sub-modules for concentrated sulfuric acid, in-situ oxidant, complexing agent and auxiliary oxidant. Each sub-module is equipped with a designed quantity delivery component to add the corresponding agent into the reactor in batches, which is adapted to the dynamic control requirements of the acid leaching system parameters. Material module: Includes slurry preparation and conveying unit and constant pressure filter separation unit, which can complete the preparation and quantitative supply of slurry, and at the same time perform solid-liquid separation on the slurry after acid leaching, complete the external delivery of lead-silver slag, reuse of washing water and export of filtrate, and build a material flow system for the entire acid leaching process; Control module: It is a central controller with a built-in multi-parameter coupled control model, equipped with a data storage and parameter early warning module. Based on the real-time parameters collected by the monitoring module, it coordinates and controls the operation status of the reaction, dosing and material modules, and records the entire process operation data synchronously.

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