Process method for synergistically recovering indium and germanium from zinc leaching residues and preparing single crystal

Abstract

The invention relates to the field of semiconductor single crystal material preparation processes, and discloses a process method for synergistically recovering indium and germanium from zinc leaching residues and preparing single crystals, which comprises the following steps: mixing a crude extract and a liquid metal solvent, carrying out low-temperature extraction to obtain mixed slurry, carrying out thermal-phase in-situ purification on the mixed slurry, separating a liquid-solid phase by utilizing thermal gradient migration, and carrying out solid-liquid separation on the separated liquid-solid phase. Performing directional solidification and purification to obtain an ultra-clean growth solution; analyzing the indium-germanium proportion of the ultra-clean growth solution, and supplementing pure metal for chemical component calibration; the ultra-clean growth solution with accurate components is used for liquid phase epitaxial growth to obtain single crystals, the thermodynamic principle is used for replacing physical filtration, so that particle heterogeneous nucleation centers are removed, the influence of chemical fluctuation of raw materials is eliminated through a built-in calibration link, and the physically pure growth solution with accurate components is prepared; the industrial preparation of the high-quality single crystal is ensured.

Description

Technical Field

[0001] This invention relates to a process for co-recovering indium germanium from zinc leaching residue and preparing single crystals, belonging to the field of semiconductor single crystal material preparation technology. Background Technology

[0002] Currently, solution-based methods, particularly liquid phase epitaxy, are crucial for preparing high-quality single-crystal materials and are a core technological step in obtaining specific functional devices. The fundamental premise for this process is obtaining a growth solution that is both physically clean and chemically precise. Traditionally, the preparation of such a growth solution has primarily involved two methods: hydrometallurgy and high-temperature melt physics. The hydrometallurgical approach relies on strong acid dissolution, multi-stage extraction, and precipitation processes, which generate significant waste liquid and are complex. High-temperature melt physics methods, such as zone melting or Czochralski, are also important. However, this approach consumes a huge amount of energy, and its original design is intended to process raw materials with high purity, making it unable to directly handle complex metallurgical waste containing large amounts of oxides or silicates. To avoid the shortcomings of the above two approaches, the industry has adopted a strategy of using mild process conditions combined with mechanical filtration methods, such as high-temperature resistant ceramic filters, in order to separate and prepare growth solutions from complex metallurgical crude extracts, i.e., solid-liquid mixed slurries. However, when this conventional chemical or metallurgical separation method is directly applied to the precision field of single crystal growth, its fundamental shortcomings will directly affect the process results.

[0003] While these traditional hydrometallurgical processes solve the recycling problem, they also introduce new and more difficult obstacles to overcome in the subsequent semiconductor single crystal growth process, which requires extremely high purity. For example, Chinese invention patent CN102703707A discloses a method for recovering indium and germanium from zinc leaching slag. This method adopts the traditional hydrometallurgical approach, firstly through sulfuric acid leaching and purification, then using hydroxamic acid and P204 kerosene for synergistic extraction of indium and germanium, followed by ammonium fluoride back-extraction of germanium, ammonia precipitation of germanium, and hydrochloric acid back-extraction of indium. Finally, indium ingots and germanium concentrates are obtained through aluminum plate replacement and low-temperature roasting, respectively. The core products of this technical route are indium ingots and germanium concentrates, and its purpose is to extract these two metals from low-grade slag, with a recovery rate of up to [percentage missing]. However, this hydrometallurgical technology, which uses concentrates or crude ingots as end products, still produces products in powder, block, or alloy form. These products cannot be directly used as the physically clean and chemically precise growth solutions required for liquid phase epitaxial growth. More importantly, the hydrometallurgical process inevitably introduces or leaves micron- or even nano-sized solid impurity particles during multiple chemical reactions, precipitation, filtration, and calcination. If such products are used as raw materials for subsequent single crystal growth, their inherent oxide precursors have extremely poor solubility in low-temperature liquid metal solvents, ultimately forming only an uneven suspension slurry, which cannot initiate liquid phase epitaxial growth at all. The traditional hydrometallurgical route cannot achieve the preparation of high-quality single crystal materials from zinc leaching slag.

[0004] Therefore, the technical problem to be solved by this invention is how to provide a growth solution that is physically clean and chemically precise for subsequent liquid-phase epitaxial growth, starting from raw materials such as zinc leaching residue with complex composition, and under mild non-aqueous and non-molten phase process conditions, so as to simultaneously solve the two core problems of physical removal of heterogeneous nucleation centers of suspended particles and precise control of target chemical components. Summary of the Invention

[0005] This invention provides a process for the co-recovery of indium and germanium from zinc leaching residue and the preparation of single crystals. Its main purpose is to solve the problem of how to remove the particulate heterogeneous nucleation centers that cause crystal growth failure when preparing single crystal growth solutions from complex raw materials using a mild process route, while simultaneously achieving precise control of the chemical composition of the solution.

[0006] To achieve the above objectives, the present invention provides a process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals, the method comprising: Step 101, low-temperature extraction: The crude extract of zinc leaching residue is mixed with a liquid metal solvent and extracted at 200°C. Up to 600 The temperature is maintained to allow indium and germanium in the crude extract to dissolve in the liquid metal solvent, forming a mixed slurry containing the liquid metal solution and solid impurity slag. Step 102, in-situ thermal phase purification: The mixed slurry is placed in a first heating vessel and a second purification vessel with a thermal gradient. The temperature of the first heating vessel is... Temperature higher than the second purification vessel The difference in thermal conductivity between the liquid metal solution and the solid impurity slag is used to drive the liquid metal solution to migrate to the second purification vessel, while the solid impurity slag is retained. The temperature of the second purification vessel is lowered below the freezing point of the liquid metal solvent, causing the liquid metal solution to solidify in a directional manner, thus repelling and enriching the suspended particulate impurities in the finally solidified liquid phase. The liquid phase is removed, and the solidified pure solid solvent in the second purification vessel is remelted to obtain an ultra-clean growth solution. Step 103, chemical composition calibration, analyze the actual component ratio of indium and germanium in the ultra-clean growth solution; based on the difference between the actual component ratio and a target component ratio, add pure indium or pure germanium material to the ultra-clean growth solution to adjust the ratio of indium and germanium in the ultra-clean growth solution to the target component ratio. Step 104, liquid phase epitaxial growth: the ultra-clean growth solution calibrated in step 103 is used as the growth solution, a single crystal seed is introduced, and the temperature is lowered to allow indium and germanium to grow on the single crystal seed to form an indium-germanium alloy single crystal.

[0007] Preferably, the liquid metal solvent is selected from pure gallium or gallium-based alloys, and the gallium-based alloys are gallium-indium alloys or gallium-tin alloys. Gallium or gallium-based alloys are used as liquid metal solvents because gallium or gallium-based alloys have high solubility for indium and germanium at the working temperature in step 101, but low solubility for oxides and silicate components in solid impurity slag.

[0008] Preferably, in step 102, the temperature of the first heating vessel... Maintain at 300 Up to 500 The temperature of the second purification reactor Maintain at 30 Up to 100 This is to establish a thermal gradient between the two.

[0009] Preferably, in step 102, lowering the temperature of the second purification vessel below the freezing point of the liquid metal solvent is achieved by using a pump that operates at 0.5 kilowatt-hours per hour. Up to 5 The cooling rate is achieved; directional solidification is based on the solute partition law, which makes the partition coefficient of particulate impurities much less than 1, thereby ensuring that particulate impurities are rejected by the solid-liquid interface of the pure solid solvent and enriched in the liquid phase.

[0010] Preferably, in step 103, the analysis of the actual component ratio of indium and germanium in the ultra-clean growth solution is achieved by inductively coupled plasma atomic emission spectrometry or X-ray fluorescence spectrometry.

[0011] Preferably, in step 104, the cooling is achieved by a process of 0.1 liters per hour. Up to 1 It is achieved through a precise cooling process.

[0012] Preferably, the method further includes step 105, solvent regeneration, recovering the remaining growth solution from step 104 and returning it as a liquid metal solvent to step 101 for recycling.

[0013] Preferably, in step 104, the single crystal seed is a germanium single chip or a silicon single chip.

[0014] Preferably, in step 103, the target component ratio is determined based on the target alloy component x value of the desired indium-germanium alloy single crystal, and the chemical formula of the indium-germanium alloy single crystal is: .

[0015] Preferably, the method further includes step 103A, total concentration calibration, after step 103 and before step 104, determining the total concentration of indium and germanium in the ultra-clean growth solution after calibration in step 103. ; Total concentration With a preset target total concentration Comparison; when total concentration Higher than the target total concentration At that time, pure liquid metal solvent is added as a diluent to the ultra-clean growth solution calibrated in step 103. The mass of the added diluent is... This is determined through the following relationship: ,in, The current mass of the liquid metal solvent in the ultra-clean growth solution after calibration in step 103 is obtained, and the total concentration calibration solution is obtained; and step 104 is modified accordingly to: Step 104, liquid phase epitaxial growth, using the total concentration calibration solution as the growth solution, introducing a single crystal seed, and cooling to allow indium and germanium to grow on the single crystal seed to form an indium-germanium alloy single crystal.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention utilizes the same low-melting-point liquid metal medium to assume two traditionally completely separate technical roles in the same process flow: firstly, it serves as a selective extraction solvent at low temperatures to prepare a liquid solution rich in target elements from industrial crude extracts; subsequently, this solution is used directly as the mother liquor for single crystal growth without replacement. This process architecture, which unifies upstream solution preparation and downstream crystal growth within a mild, non-aqueous, non-high-temperature molten phase system through the unification of the core medium, establishes a continuous path from complex industrial raw materials to high-purity single crystal materials, changing the traditional process prerequisite in the field of single crystal growth that must rely on high-purity starting materials.

[0017] 2. Before the core step of single crystal growth (liquid phase epitaxy), a collaborative step of component analysis and component calibration is set up. The design of this step is based on the deep understanding that there are natural and uncontrollable batch-to-batch fluctuations in the chemical composition of upstream industrial crude extracts. Such fluctuations are fatal to the downstream preparation of alloy single crystals with specific compositions. This invention constructs a diagnostic and compensatory process closed loop by actively sampling and analyzing the liquid metal solution before growth, and making precise physical feeding adjustments based on the difference between the analysis results and the preset target composition. It cuts off the transmission path of the uncertainty of raw material composition to the consistency of the final single crystal product in the process flow, making it possible to reproduce alloy single crystals with specific compositions using industrial waste with compositional fluctuations.

[0018] 3. By introducing an in-situ purification mechanism based on thermodynamics and phase transition principles, the fundamental limitation of mechanical filtration in removing particulate impurities is systematically addressed. This mechanism first utilizes the physical difference in thermal conductivity between liquid metal and solid slag, applying a thermal gradient to drive the liquid metal solution to migrate non-contactly to the purification area, achieving coarse separation from the solid slag. Then, a controllable directional solidification process is initiated within the purification area, utilizing the repulsion effect of the liquid-solid phase transition interface on particulate impurities to systematically drive away and enrich heterogeneous nucleation centers that cause disordered crystal growth into the final solidified waste liquid. This ultra-clean solution preparation method, which relies entirely on thermal field control and the law of phase transition rather than mechanical barriers, ensures that during subsequent single crystal growth, the crystal grows exclusively and orderly only on the seed crystal surface. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the synergistic recycling and single crystal preparation of the present invention; Figure 2 This is a comparison graph of the total concentration and supersaturation index of the solution before and after the total concentration calibration of this invention; Figure 3 This diagram shows the correspondence between the core stages of the process and the key elements, materials, and controls of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] The present invention discloses a process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals. Its overall technical architecture comprises four core stages: First, step 101 involves low-temperature extraction, using a liquid metal solvent to selectively dissolve the target metal in the raw material; subsequently, step 102 involves in-situ thermal purification, achieving physical purification through thermodynamic principles rather than mechanical filtration; next, step 103 involves chemical composition calibration, precisely balancing the chemical composition of the purified solution; finally, step 104 involves liquid-phase epitaxial growth, utilizing the physically purified... The target single crystal is prepared from a clean and precisely composed solution. Specifically, the low-temperature extraction in step 101 uses zinc leaching residue as the starting material. This residue is a complex mixture containing the target products indium and germanium, as well as a large amount of solid impurity slag, such as oxides and silicate components. To achieve preliminary separation of the target metal from the impurity slag under mild conditions, this method introduces a liquid metal solvent, preferably pure gallium or a gallium-based alloy, such as a gallium-indium alloy or a gallium-tin alloy. The engineering basis for selecting such solvents is that they have a low viscosity at 200°C. Up to 600 Within its low-temperature operating range, it exhibits high chemical solubility for indium and germanium, but extremely low solubility for solid impurity slag components such as oxides and silicates. During operation, the crude extract is mixed with a liquid metal solvent and then, for example, at 300°C... Up to 500 The preferred operating temperature is maintained so that indium and germanium are fully dissolved in the liquid metal solvent, while the solid impurity slag is suspended in the form of insoluble matter, thereby forming a mixed slurry containing liquid metal solution and solid impurity slag.

[0022] Subsequently, the mixed slurry enters the in-situ thermal phase purification stage in step 102. This step is used to remove micron- and nano-sized suspended particles that cannot be removed by conventional mechanical filtration. These particles are interference sources that may cause unintended nucleation during subsequent single crystal growth. To remove these particles, this step adopts a dual-reactor thermodynamic separation design, placing the mixed slurry in a first heating vessel and a second purification vessel. The temperature of the first heating vessel is controlled. For example, maintaining at 300 Up to 500 Temperature higher than the second purification vessel For example, maintaining at 30 Up to 100 This establishes a controlled thermal gradient. Based on the high thermal conductivity of the liquid metal solution and the low thermal conductivity of the solid slag impurities, this difference in properties drives the liquid metal solution to migrate to the second purification vessel, while most of the solid slag impurities remain in the first heating vessel due to thermodynamic effects. After this initial thermal migration and coarse separation, to remove suspended particulate impurities entrained in the second purification vessel, this step further utilizes the phase change purification principle of directional solidification. Specifically, the temperature of the second purification vessel is increased at a rate of 0.5°C per hour. Up to 5 The temperature is gradually reduced to below the freezing point of the liquid metal solvent. During this directional solidification process, according to the solute partition law, the partition coefficient of suspended particulate impurities with different physicochemical properties in the solid solvent is much less than 1. Therefore, they are repelled by the solid-liquid interface of the growing pure solid solvent and enriched in the final solidified liquid phase. When solidification is nearing completion, this final solidified liquid phase enriched with all particulate impurities is removed by physical means. Subsequently, the remaining solidified pure solid solvent in the second purification vessel is remelted to obtain an ultra-clean growth solution.

[0023] The core of the in-situ thermal phase purification unit in step 102 lies in establishing and maintaining a controllable temperature gradient field to drive the migration and separation of the liquid and solid phases. The first heating vessel ( ) and the second purification vessel ( Thermodynamic coupling is achieved through a connecting channel with specific geometric dimensions to ensure efficient separation and adequate retention of solid impurities (slag), creating an effective thermal gradient between the two reactors. Maintained at to Within the interval, where for and difference, The distance between the center points of the two temperature sensors and the migration time of the liquid metal solution driven by the thermal gradient are determined by pre-calculation using heat transfer models of slurries with different viscosities, and the migration holding time is set. It needs to be greater than one empirical characteristic time. of This migration time is doubled to ensure that the indium-germanium-rich liquid metal solution is fully transferred to the second purification vessel. The recovery rate of the liquid metal solution at the outlet of the first heating vessel was achieved by monitoring the recovery rate. The time consumed is used to define this thermal migration coarse separation method, which utilizes the inherent difference in thermal conductivity to circumvent the physical upper limit of particle size constraints imposed by mechanical filtration; in step 102, the directional coagulation purification stage, the temperature of the second purification vessel is increased by 100°C per hour. to The rate of solidification decreases below the freezing point of the liquid metal solvent. To accurately remove the final solidified liquid phase enriched with suspended particulate impurities, the determination of the solidification percentage is based on real-time monitoring of the solidification front temperature by a thermocouple array and analysis of the phase change enthalpy release curve: when the system temperature reaches the freezing point of the liquid metal solvent and begins to slowly decrease to a lower level, the total heat released during solidification is calculated to reach the total phase change enthalpy. The corresponding cooling time is determined. The solidification endpoint is determined by... Immediately after the solidification endpoint, a non-contact, high-pressure inert gas compression operation is initiated to remove the liquid from the central region. The enriched impurity liquid phase is directionally extruded through a bottom-mounted impurity discharge valve and collected in a separate collection container. The valve's activation and deactivation are based on real-time monitoring of the extruded liquid phase quality using a flow sensor, ensuring that only the predetermined amount of enriched liquid phase is removed. This procedure reduces the concentration of particulate impurities to below the technical specifications usable for subsequent liquid phase epitaxial growth without introducing secondary contamination. After obtaining the ultra-clean growth solution, to address the issue of fluctuations in the chemical composition of the raw material source, the process then performs step 103, chemical composition calibration. This step first requires accurate determination of the actual component ratio of indium and germanium in the ultra-clean growth solution. This determination can be achieved using well-established analytical methods in the field, such as inductively coupled plasma atomic emission spectrometry (ICP-AES) or X-ray fluorescence spectrometry (XRF). Subsequently, the measured actual component ratio is compared with a target component ratio, which is based on the target chemical formula of the desired indium-germanium alloy single crystal. Target alloy components The value is predetermined; based on the difference between the actual component ratio and the target component ratio, supplementary materials are added to the ultra-clean growth solution, namely, pure indium material or pure germanium material, until the ratio of indium and germanium in the ultra-clean growth solution is precisely adjusted to the target component ratio.

[0024] In some embodiments with higher requirements for growth kinetics, a step 103A can be added after step 103 and before step 104: total concentration calibration. This step aims to ensure that the saturation of the solution is within a preset growth window. The operation is as follows: first, the total concentration of indium and germanium in the ultra-clean growth solution after calibration in step 103 is measured. ; will With a preset target total concentration Compare; when the total concentration is found Higher than the target total concentration When the solution becomes supersaturated, it is necessary to add pure liquid metal solvent, the same solvent used in step 101, such as pure gallium as a diluent; the mass of the added diluent should be... Calculated using a defined relational expression: In the formula, The current mass of the liquid metal solvent in the ultra-clean growth solution after calibration in step 103. The total concentration to be measured, To achieve the target total concentration, this step yields a solution with a calibrated total concentration. Finally, step 104, liquid phase epitaxial growth, is performed. The ultra-clean growth solution calibrated in step 103 (or the total concentration calibrated solution calibrated in step 103A) is used as the final growth solution. A single-crystal seed crystal is introduced into this growth solution; this seed crystal can be a germanium single-chip or a silicon single-chip. Subsequently, a process of 0.1 kJ / hour is initiated. Up to 1 The precise cooling process allows the growth solution to slowly reach and maintain a slightly supersaturated state. Indium and germanium atoms in the solution undergo ordered heterogeneous nucleation and epitaxial growth on the surface of the single-crystal seed, ultimately forming a crystal with the target composition. The method further includes step 105, solvent regeneration, to achieve process economy: recovering the remaining growth solution after growth in step 104 and returning it as a liquid metal solvent to step 101 for recycling; the method includes the solvent regeneration step 105, recovering the remaining growth solution in step 104 as a liquid metal solvent and returning it to step 101 for recycling. To ensure the long-term stability of solvent quality and the feasibility of recycling, the quality of the regenerated solvent is periodically controlled: every cycle... to After each batch, non-target impurity elements (such as...) in the regenerated solvent must be analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES). , , Analyze trace metallic impurities (such as those from the leaching residue). If the concentration of any non-target impurity element exceeds [a certain value], [further analysis will be performed]. If the preset control limit is reached, the deep purification process of the solvent is initiated, which includes an additional purification process per hour. to The secondary directional solidification purification is carried out at an extremely low rate to distribute the enriched impurities to the end solidification region of the solvent and remove them, ensuring that the purity of the regenerated solvent meets the strict requirements of the purity of the starting materials for semiconductor single crystal preparation.

[0025] Example 1: This example is a specific application of the disclosed method. Its objective is to prepare an indium-germanium alloy single crystal with a specific alloy composition from a batch of zinc leaching residue crude extract with fluctuating chemical composition. Single crystal; In a specific industrial preparation scenario, the challenge lies not only in the presence of a large number of suspended, submicron-sized oxide and silicate particles in the crude zinc leaching residue, but more importantly, preliminary assessments indicate that the indium-germanium ratio of this batch of raw materials deviates significantly from the target of 0.1:0.9, and the composition of subsequent batches is expected to fluctuate further. This presents an obstacle to achieving the two prerequisites necessary for semiconductor chip growth: physical purity and chemical precision. To address this scenario, step 101 is first performed, mixing the crude zinc leaching residue with pure gallium liquid metal solvent, and heating it to 400°C in a first heating vessel under an inert atmosphere. The process continues, allowing indium and germanium in the crude extract to fully dissolve in the gallium solvent, forming a mixed slurry. At this point, the process faces a critical juncture: how to separate the liquid phase from this mixed slurry. Conventional mechanical filtration methods are not only prone to clogging but also unable to intercept submicron-sized heterogeneous nucleation centers that lead to crystal growth failure. Therefore, this embodiment instead performs in-situ thermal purification in step 102; a second purification vessel is thermodynamically coupled to the first heating vessel, and the temperature of the first heating vessel is set. Maintain at 400 And set the temperature of the second purification vessel. Maintain at 60 Utilizing the thermal gradient between the two reactors and the difference in thermal conductivity between the liquid metal solution and the solid impurity slag, the indium-germanium-rich liquid metal solution is driven to migrate to the second purification reactor, while most of the solid impurity slag remains in the first heating reactor. After migration, although most of the coarse slag has been removed from the liquid metal solution in the second purification reactor, it still carries suspended particulate impurities that cause single crystal growth failure. Therefore, a directional solidification purification process is initiated: the temperature of the second purification reactor is increased at a rate of 1.0°C per hour. The cooling rate is from 60 The temperature begins to drop; as the temperature falls below the freezing point of the gallium solvent, the pure solid solvent begins to solidify at the vessel wall. The solid-liquid interface repels suspended particulate impurities and enriches them in the last solidified liquid phase at the center. This is due to the partition coefficient of these particulate impurities in the solid solvent. Once 95% of the solution has solidified, remove the remaining 5% of the liquid phase, which contains all the particulate impurities, and then remelt the second purification vessel to 60°C. This yields a physically clean growth solution.

[0026] This ultra-clean growth solution provides a necessary prerequisite for subsequent chemical composition calibration. Without the physical eradication of heterogeneous nucleation centers in step 102, any chemical calibration would be meaningless. Therefore, step 103 is performed, and the ultra-clean growth solution is analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The actual indium-germanium composition ratio was determined to be 0.08:0.92, corresponding to the chemical formula... This is related to The target component ratio was found to be off. Based on this deviation, a calculated mass of pure indium material was precisely added to the ultra-clean growth solution and allowed to fully dissolve, adjusting the indium to germanium ratio to the target ratio of 0.1:0.9. Thus, in-situ thermal phase purification in step 102, through thermal gradient migration and directional solidification phase transformation, yielded a solution with removed heterogeneous nucleation centers. This solution provided an analyzable and harmonizable homogeneous medium for chemical composition calibration in step 103. The analysis and compensation in step 103 further ensured that the solution achieved a precisely controlled chemical composition. Finally, in step 104, this calibrated ultra-clean growth solution, free of particulate interference and with a precise chemical composition, was used for liquid phase epitaxial growth. A germanium single-chip was introduced as a single-crystal seed, and a process was initiated at 0.2 ppm per hour. A precise cooling process was employed; because there were no particles in the solution interfering with spontaneous nucleation, and the chemical composition of indium and germanium was precisely controlled, indium and germanium underwent orderly epitaxial growth only on single-crystal seed crystals, ultimately yielding a product with… High-quality indium-germanium alloy single crystals with target alloy composition.

[0027] Example 2: This example compares the effectiveness of three process methods in treating the same batch of contaminated zinc leaching residue crude extract with varying compositions. The objective of this batch of raw materials is to prepare... Alloy single crystals; three groups were set up for the experiment, all using the same batch of zinc leaching residue crude extract; this batch of raw materials was pre-tested and found to contain a high concentration of submicron-sized silicate particles, with a count greater than [missing information]. The concentration of indium / mL was measured by ICP-AES to be 0.15:0.85, which deviates from the target component ratio of 0.2:0.8. The first group, the control group D1, simulated a conventional mechanical filtration process. This group underwent low-temperature extraction in step 101, followed by extraction using a pore size of 1... The first group undergoes physical filtration using a high-temperature resistant ceramic filter screen, followed by direct liquid-phase epitaxial growth in step 104. This group does not perform the in-situ thermal purification in step 102 or the chemical composition calibration in step 103. The second group is the control group D2, simulating a process that only performs physical purification but not chemical calibration. This group performs the low-temperature extraction in step 101 and the in-situ thermal purification in step 102, followed by direct liquid-phase epitaxial growth in step 104. This group does not perform the chemical composition calibration in step 103. The third group is the sample group S1 of this invention, employing the complete process of this invention, sequentially performing steps 101, 102, 103, and 104. All groups use 1 kg of the above-mentioned raw materials and 5 kg of pure gallium liquid metal solvent, heated in a first heating vessel at 450°C. Performing low-temperature extraction in step 101 for 2 hours resulted in the formation of a mixed slurry.

[0028] Subsequently, control group D1 will use this 450 The mixed slurry is passed through 1 The solution to be grown is obtained by filtration through a ceramic filter screen; the mixed slurry of control group D2 and sample group S1 of this invention is transferred to a dual-reactor purification unit to perform in-situ thermal phase purification in step 102. The specific parameters are as follows: the first heating vessel is set... Maintain at 450 Second purification reactor Maintain at 50 Thermal gradient migration is performed; after the migration is completed, the second purification vessel is subjected to a 2 Cooling is performed at a rate of / hr to induce directional solidification. After 95% solidification of the solution in the reactor, the remaining 5% of the liquid phase enriched with impurities is removed. The pure solid solvent in the reactor is then remelted to obtain an ultra-clean growth solution. After obtaining the respective growth solutions, intermediate testing is performed, including using a laser particle size analyzer to detect particles larger than 0.5 μm. The number of particulate impurities m was measured, and the indium-germanium composition ratio was detected using ICP-AES. After the detection was completed, sample group S1 of the present invention, based on the difference between the actual composition ratio of 0.15:0.85 measured by ICP-AES and the target composition ratio of 0.2:0.8, performed step 103, adding a calculated mass of pure indium material to its ultra-clean growth solution and stirring to dissolve it, so that its composition ratio was calibrated to 0.2:0.8; control groups D1 and D2 did not perform any chemical composition calibration; finally, the final solutions of the three groups, namely the filtered solution of D1, the ultra-clean growth solution of D2, and the calibrated ultra-clean growth solution of S1, were placed in the same liquid phase epitaxial growth furnace, and a germanium single chip with (100) crystal orientation was introduced as a single crystal seed crystal, and 0.5 The precise cooling procedure of / hr executes step 104 of liquid phase epitaxial growth; after growth, the product is removed, its crystal structure is analyzed by X-ray diffraction (XRD), and its final alloy composition is analyzed by energy-dispersive X-ray spectroscopy (EDX). The values ​​and experimental results are summarized in Table 1.

[0029] Table 1: Effects of different purification and calibration processes on single crystal growth results The data analysis in Table 1 shows that, compared with control group D2, conventional mechanical filtration (group D1) cannot remove suspended particulate impurities from the solution before growth, and the number of particles remains as high as [missing data]. These particles, at a density of 10 particles / mL, acted as heterogeneous nucleation centers during the cooling process, leading to a large number of spontaneous nucleations and ultimately resulting in a polycrystalline mixture from which single crystals could not be obtained. Conversely, the D2 group, purified in situ using the thermal phase in step 102, reduced the number of particles in its solution to the detection limit (<10 particles / mL), achieving a physically clean growth solution and thus avoiding spontaneous nucleation, resulting in structurally complete single crystals. This confirms the effectiveness of step 102 in removing heterogeneous nucleation centers. Furthermore, a comparison between the control group D2 and the sample group S1 of this invention shows that although the D2 group obtained physically pure single crystals, its alloy composition was affected because the chemical calibration in step 103 was not performed. The value is 0.15, which replicates the component ratio at the raw material end, deviating from the target of 0.20; while the sample group S1 of this invention, based on group D2, adds the chemical composition calibration in step 103, and the final single crystal alloy composition obtained is... The value is 0.20 0.01, highly consistent with the target composition; experimental data show that the in-situ thermal phase purification in step 102 is a key prerequisite for obtaining a physically clean solution and realizing single crystal growth. It solves the problem that mechanical filtration cannot remove the heterogeneous nucleation centers of microparticles; the chemical composition calibration in step 103 is a key prerequisite for obtaining products with accurate chemical composition, avoiding the problem of inconsistent product batches caused by fluctuations in raw material composition.

[0030] To further verify the non-obviousness of the integrated liquid metal extraction-purification path (steps 101 and 102) used in the method of the present invention compared with the traditional hydrometallurgical path, the following comparative examples were set up.

[0031] Example 3: A comparative example D3 was set up, the process flow of which was compared with that of sample group S1 in Example 2 of the present invention. The difference was that: comparative example D3 used a conventional hydrometallurgical process to replace steps 101 (low-temperature liquid metal extraction) and 102 (thermal phase in-situ purification) of the present invention, and then attempted to perform liquid phase epitaxial growth in step 104; comparative example D3 used the same starting material as sample group S1 in Example 2, namely 1 kg of the same batch of zinc leaching residue crude extract. This batch of raw material contained a high concentration of submicron silicate particles, and the indium-germanium mass ratio was determined to be 0.15:0.85; the process flow of comparative example D3 first performed the hydrometallurgical purification step: step 101 of the present invention was not performed, but 1 kg of crude extract was treated by a conventional hydrometallurgical process; specifically, the crude extract was placed in an acid-resistant reactor, 5 L of 2M sulfuric acid solution was added, and the mixture was heated at 80°C. The solution was leached with stirring for 4 hours; the leachate was then filtered under pressure, and the filtrate was transferred to a multi-stage extraction tank for selective extraction and back-extraction using P204 extractant to separate indium and germanium; the back-extraction solutions were combined, and the pH was adjusted to 3.5 to co-precipitate indium and germanium into a mixed hydroxide; the precipitate was filtered, washed, and then subjected to a 600°C test. After calcination for 2 hours, 45g of indium-germanium mixed oxide powder was finally obtained; this process generated approximately 6.2L of highly hydrochloric acid wastewater.

[0032] Subsequently, an attempt was made to prepare the growth solution: all 45g of the mixed oxide powder obtained in the above steps were added to 5kg of pure gallium liquid metal solvent (the same mass as the solvent in the S1 sample group), and the temperature was raised to 450°C. (Extraction temperature same as S1 sample group), stir for 2 hours; at 450 Observations revealed that the indium-germanium mixed oxide powder hardly dissolved in liquid gallium solvent, but instead remained highly dispersed in the gallium solvent as solid particles, forming a non-uniform suspension slurry. This high-temperature suspension slurry was transferred to a liquid phase epitaxial growth furnace, and a (100) oriented germanium single-chip was introduced as a single-crystal seed, and the same 0.5 km / h growth rate as the S1 sample group was applied. The precise cooling procedure was followed; after the growth was completed, the seed crystal was removed, and it was observed that no epitaxial growth of indium-germanium alloy occurred on the surface of the seed crystal; the residue in the crucible was analyzed, and it was found to be a physical mixture of solid gallium metal and undissolved indium-germanium mixed oxide powder. The results of the comparative experiments are summarized in Table 2.

[0033] Table 2: Comparison of the Invention Path (S1) and the Conventional Wet Process Path (D3) The results of Comparative Example D3 show that the product (oxide) obtained by the conventional C22B hydrometallurgical route is not physicochemically compatible with the liquid metal solvent (gallium) used for C30B low-temperature liquid phase epitaxial growth. The oxide precursor does not dissolve in the low-temperature gallium solvent and cannot form the supersaturated solute solution necessary for crystal growth. Therefore, liquid phase epitaxial growth cannot be initiated, resulting in process failure.

[0034] Example 4: This example combines Figures 1 to 3 This describes a process for the co-recovery of indium and germanium from zinc leaching residue and the preparation of single crystals, as follows: Figure 1As shown, this method uses zinc leaching residue crude extract and liquid metal solvent such as pure gallium or gallium-based alloys as starting materials. First, a low-temperature extraction in step 101 is performed to dissolve indium and germanium, forming a mixed slurry. This mixed slurry then enters the thermal phase in-situ purification stage in step 102. This stage aims to remove heterogeneous nucleation centers of microparticles and specifically includes three sub-steps: thermal gradient migration coarse separation, directional solidification fine purification, and removal of impurities from the liquid phase followed by remelting, thereby obtaining an ultra-clean growth solution. This ultra-clean growth solution then enters the chemical composition calibration stage in step 103, where the indium-germanium ratio is calibrated by analyzing and supplementing with pure metal. After obtaining the calibrated solution, in an optional key module, the total concentration calibration of the calibrated solution can be further performed in step 103A. By comparing the target concentration and adding solvent for dilution, a total concentration calibration solution is obtained. Finally, the calibrated solution or the total concentration calibration solution enters the liquid phase epitaxial growth stage in step 104. By introducing seed crystals and growing at a precise temperature, the target product, indium-germanium alloy single crystal, is prepared. In addition, the method also includes solvent regeneration in step 105, which recovers the remaining growth solution generated in step 104 and returns it to step 101 for recycling as a liquid metal solvent.

[0035] like Figure 2 As shown, the chart contains two Y-axis: the left Y-axis represents the total concentration (%), and the right Y-axis represents the supersaturation index. The X-axis distinguishes between before and after calibration. As shown in the data bars, both the total concentration and the supersaturation index were at high levels before calibration, while after total concentration calibration, both the total concentration and the supersaturation index were reduced to a controlled low level. Figure 3 As shown, the top layer of the roadmap clearly indicates the four core process stages and their key operations: namely, the low-temperature extraction stage, for example, at 200... Up to 600 The process involves several stages: thermal insulation to form a mixed slurry; in-situ purification of the thermal phase by removing heterogeneous nucleation centers; directional solidification purification and thermal gradient migration separation; chemical composition calibration, including total concentration calibration, supplementation of pure metals, analysis of actual component ratios; and liquid phase epitaxial growth using a precise cooling program, introduction of single-crystal seed crystals, and the use of calibrated ultra-clean solutions. Ultimately, this process achieves the preparation of high-quality indium-germanium alloy single crystals. The bottom layer of this roadmap summarizes the key elements required to achieve the above process and vertically corresponds them to the top layer stages: the key materials module includes zinc leaching residue crude extract, gallium-based liquid metal solvent, and single-crystal seed germanium / silicon, which vertically correspond to the low-temperature extraction stage; while the analysis and control module includes component analysis ICP / XRF, thermal gradient control, and precise cooling rate control, which vertically correspond to the chemical composition calibration stage.

[0036] Example 5: This example records the preparation of the target alloy composition as follows: The calibration and application procedures for key process parameters of alloy single crystals; first, the target total concentration required for calibration step 104. A series of test melts were prepared, each containing 100g of pure gallium liquid metal solvent, and each melt was dissolved with a pre-mixed indium-germanium alloy in a mass ratio of 0.3:0.7, with the mass of the alloy increasing from 1g to 10g. The solidification point, i.e., the liquidus temperature, of each test melt was determined by differential scanning calorimetry (DSC). The liquidus temperature was measured when the alloy material addition was 5.0g. It is 451.2 When the amount added is 5.5g, It is 462.5 Based on this data, the initial growth temperature for step 104 is set to 460°C. The corresponding target total concentration The concentration was determined to be 5.4 g alloy / 100 g gallium, i.e., a total solute mass fraction of 5.12%; subsequently, the process parameters of step 102 were calibrated; using the same contaminated crude extract raw material as in Example 2, three sets of gradient tests were set: Test group A was set as follows: 450 , For 60 Experimental group B was set up 450 , 150 (above 100) Upper limit); Experimental group C setting 250 (Below 300) (lower limit) For 60 After performing thermal gradient migration, the recovery rate of the liquid metal solution that migrated to the second purification vessel was measured; the recovery rate of experimental group A was 98.8%; the recovery rate of experimental group B was... Excessive heat, insufficient thermal gradient, and turbidity of the migration products; experimental group C due to... If the temperature is too low, the liquid phase is retained by the slag, resulting in a recovery rate of only 61.3%; based on this, it is determined that... In 300 Up to 500 and In 30 Up to 100 High-efficiency thermal migration can be achieved within a certain range.

[0037] To calibrate the cooling rate of directional solidification in step 102, a cooling rate gradient experiment was conducted using the high-recovery solution (still containing suspended particles) obtained from test group A: the solution was divided into three portions, each cooled at a rate of 1.0... / hr, 4.0 / hr and 10.0 / hr (higher than 5) Directional coagulation purification was performed at a rate of (maximum / hr); the resulting ultra-clean growth solution was used in subsequent step 104 growth; 1.0 / hr and 4.0 Solutions purified at a rate of / hr all grew single crystals; while those purified at 10.0 The solution purified at a rate of / hr produced a polycrystalline mixture as its growth product. This result indicates that an excessively rapid cooling rate leads to the trapping of particulate impurities at the solid-liquid interface, rendering the impurity removal effect of directional solidification ineffective. Therefore, a cooling rate of 0.5 h / hr was determined. Up to 5 The cooling rate is the process window for achieving phase change purification; using the parameters calibrated above ( 450 , 60 Cooling rate 1.0 ( / hr) Perform steps 101 and 102 to obtain a 5025g ultra-clean growth solution; perform step 103 to analyze the solution by ICP-AES, and its composition is determined to be: indium (In) 196.0g, germanium (Ge) 784.0g, and gallium (Ga) solvent 4045g; The actual ratio is 0.2:0.8, which is consistent with this embodiment. The target component ratio is incorrect; to calibrate to 0.3:0.7, additional pure indium needs to be added. Through mass balance calculations: Calculated g; Add 140.0 g of pure indium to the solution and dissolve it; after calibration, the total mass of solute in the solution is g, total solution mass is g, total concentration for ;this (21.68%) is higher than the value specified in the first step of this embodiment. (5.12%), perform total concentration calibration in step 103A; replenish the mass of pure liquid metal solvent (Ga) added. According to the formula Perform calculations; among which, It weighs 4045g. The ratio is 21.68 / 5.12, which is 4.234; the calculation yields... g; Add 13083.0 g of pure gallium to the solution and mix thoroughly to obtain a total concentration calibration solution with a total concentration of 5.12% and a component ratio of 0.3:0.7; Use this total concentration calibration solution in step 104, at 460 To establish the initial growth temperature, a germanium single-crystal seed crystal was introduced, and a temperature of 0.1 was set. Liquid phase epitaxial growth was performed using a precise cooling program of / hr; after growth, a crystal phase with complete crystal structure and no polycrystalline defects was obtained, and the alloy composition was determined by EDX. The target single crystal.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals, characterized in that, The method includes: Step 101, low-temperature extraction: The crude extract of zinc leaching residue is mixed with a liquid metal solvent and extracted at 200°C. Up to 600 The temperature is maintained to allow indium and germanium in the crude extract to dissolve in the liquid metal solvent, forming a mixed slurry containing the liquid metal solution and solid impurity slag. Step 102, in-situ thermal phase purification: The mixed slurry is placed in a first heating vessel and a second purification vessel with a thermal gradient. The temperature of the first heating vessel is... Temperature higher than the second purification vessel The difference in thermal conductivity between the liquid metal solution and the solid impurity slag is used to drive the liquid metal solution to migrate to the second purification vessel, while the solid impurity slag is retained. The temperature of the second purification vessel is lowered below the freezing point of the liquid metal solvent, causing the liquid metal solution to solidify in a directional manner, thus repelling and enriching the suspended particulate impurities in the finally solidified liquid phase. The liquid phase is removed, and the solidified pure solid solvent in the second purification vessel is remelted to obtain an ultra-clean growth solution. Step 103, chemical composition calibration, analyze the actual component ratio of indium and germanium in the ultra-clean growth solution; based on the difference between the actual component ratio and a target component ratio, add pure indium or pure germanium material to the ultra-clean growth solution to adjust the ratio of indium and germanium in the ultra-clean growth solution to the target component ratio. Step 104, liquid phase epitaxial growth: the ultra-clean growth solution calibrated in step 103 is used as the growth solution, a single crystal seed is introduced, and the temperature is lowered to allow indium and germanium to grow on the single crystal seed to form an indium-germanium alloy single crystal.

2. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, The liquid metal solvent is selected from pure gallium or gallium-based alloys, which are gallium-indium alloys or gallium-tin alloys. Gallium or gallium-based alloys are used as liquid metal solvents because gallium or gallium-based alloys have high solubility for indium and germanium at the working temperature in step 101, but low solubility for oxides and silicate components in solid impurity slag.

3. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 102, the temperature of the first heating vessel... Maintain at 300 Up to 500 The temperature of the second purification reactor Maintain at 30 Up to 100 This is to establish a thermal gradient between the two.

4. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 102, the temperature of the second purification vessel is lowered below the freezing point of the liquid metal solvent by a process that reduces the temperature by 0.5 kWh per hour. Up to 5 The cooling rate is achieved; directional solidification is based on the solute partition law, making the partition coefficient of particulate impurities much less than 1.

5. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 103, the actual component ratio of indium and germanium in the ultra-clean growth solution is analyzed by inductively coupled plasma atomic emission spectrometry or X-ray fluorescence spectrometry.

6. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 104, the cooling is achieved by applying a cooling rate of 0.1 liters per hour. Up to 1 A precise cooling process is achieved.

7. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, The method also includes step 105, solvent regeneration, recovering the remaining growth solution from step 104 and returning it as a liquid metal solvent to step 101 for recycling.

8. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 104, the single crystal seed crystal is a germanium single chip or a silicon single chip.

9. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, In step 103, the target component ratio is determined based on the target alloy component x value of the desired indium-germanium alloy single crystal. The chemical formula of the indium-germanium alloy single crystal is: .

10. The process for co-recovering indium and germanium from zinc leaching residue and preparing single crystals according to claim 1, characterized in that, The method, following step 103 and preceding step 104, also includes step 103A, total concentration calibration, which measures the total concentration of indium and germanium in the ultra-clean growth solution after calibration in step 103. ; Total concentration With a preset target total concentration Comparison; when total concentration Higher than the target total concentration At that time, pure liquid metal solvent is added as a diluent to the ultra-clean growth solution calibrated in step 103. The mass of the added diluent is... This is determined through the following relationship: ,in, The current mass of the liquid metal solvent in the ultra-clean growth solution after calibration in step 103 is obtained, and the total concentration calibration solution is obtained; and step 104 is modified accordingly to: Step 104, liquid phase epitaxial growth, using the total concentration calibration solution as the growth solution, introducing a single crystal seed, and cooling to allow indium and germanium to grow on the single crystal seed to form an indium-germanium alloy single crystal.

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