A process for synergistically recovering indium and germanium from zinc leaching residue and preparing single crystal

Abstract

The application relates to the field of semiconductor single crystal material preparation processes, and discloses a process method for cooperatively recovering indium and germanium from zinc leaching residue and preparing single crystals, which comprises the following steps: mixing crude extract and a liquid metal solvent to carry out low-temperature extraction to obtain mixed slurry, performing hot-phase in-situ purification on the mixed slurry, separating liquid and solid phases by using thermal gradient migration, and then obtaining an ultraclean growth solution by directional solidification purification; analyzing the indium-germanium ratio of the ultraclean growth solution, and supplementing pure metal to perform chemical component calibration; and using the component-accurate ultraclean growth solution to perform liquid-phase epitaxial growth to obtain single crystals; the application replaces physical filtration with thermodynamic principles to remove particulate heterogeneous nucleation centers, and eliminates the influence of raw material chemical fluctuations by using an internal calibration link to prepare a physically clean and component-accurate growth solution, thereby guaranteeing the industrialized preparation of high-quality single crystals.

Description

TECHNICAL FIELD

[0001] The application relates to a process method for cooperatively recovering indium and germanium from zinc leaching residue and preparing single crystals, and belongs to the technical field of semiconductor single crystal material preparation processes. BACKGROUND

[0002] At present, high-quality single crystal materials are prepared by adopting a solution method, in particular a liquid phase epitaxy method, and the method is a core process link for obtaining specific functional devices. The most fundamental prerequisite for the process is to obtain a growth solution which is highly clean in physical structure and highly accurate in chemical composition. Traditionally, there are two ways for preparing the growth solution, i.e., a hydrometallurgy method and a high-temperature melt physics method. The hydrometallurgy method depends on strong acid dissolution, multi-stage extraction and precipitation processes, and the processes will generate more waste liquid and are complex. The high-temperature melt physics method, such as a zone melting or a pulling method, has huge energy consumption, and the method is originally designed to process raw materials with high purity and cannot directly deal with metallurgical waste residues with complex sources and a large amount of oxides or silicates. In order to avoid the shortcomings of the two methods, there is a thought of adopting a mild process condition and combining a mechanical filtration method, for example, a high-temperature resistant ceramic filter screen, to separate and prepare a growth solution from a complex composition metallurgical crude extract, i.e., a solid-liquid mixed slurry. However, when the conventional chemical or metallurgical separation method is directly applied to the field of precise single crystal growth, the principle deficiency will directly affect the process result.

[0003] These traditional wet processes, while solving the problem of recycling, bring new and more difficult obstacles to the subsequent semiconductor single crystal growth process which requires extremely high purity, for example, the Chinese invention patent with publication number CN102703707A discloses a method for recovering indium and germanium from zinc leaching residue. The method uses the traditional hydrometallurgical approach, first through sulfuric acid leaching and impurity removal, 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, and finally through aluminum plate displacement and low temperature roasting to obtain indium ingot and germanium concentrate respectively. The core product of this technical route is indium ingot and germanium concentrate, and the purpose is to extract these two metals from low-grade slag, with a recovery rate of more than 95%. However, this hydrometallurgical technology with concentrate or crude ingot as the final product is still in the form of powder, block or alloy, which cannot be directly used as the physical highly clean and chemically highly accurate growth solution required for liquid phase epitaxial growth. More importantly, in the process of multiple chemical reactions, precipitation, filtration and calcination, micron or even nanometer solid impurity particles are inevitably introduced or left. If such products are used as raw materials for subsequent single crystal growth, the inherent oxide precursor has very poor solubility in low-temperature liquid metal solvent, and can only form a non-uniform suspended slurry, which cannot start liquid phase epitaxial growth. The traditional hydrometallurgical route cannot realize the preparation of high-quality single crystal materials from zinc leaching residue.

[0004] Therefore, how to provide a process for starting from complex zinc leaching residue and other raw materials, under the conditions of a mild non-aqueous phase and non-molten phase, to simultaneously solve the two core problems of physical removal of suspended particle heterogeneous nucleation centers and accurate control of target chemical components, so as to prepare a physically clean and chemically accurate growth solution for subsequent liquid phase epitaxial growth, has become a technical problem to be solved by the present application. SUMMARY

[0005] The present application provides a process for simultaneously recovering indium and germanium from zinc leaching residue and preparing single crystals, which is mainly aimed at solving the problem of how to remove the particle heterogeneous nucleation centers that cause crystal growth failure and simultaneously achieve accurate control of the chemical components of the solution when using a mild process route to prepare single crystal growth solution from complex raw materials.

[0006] To achieve the above-mentioned purpose, the present application provides a process for simultaneously recovering indium and germanium from zinc leaching residue and preparing single crystals, which comprises:

[0007] Step 101, low-temperature extraction, mixing zinc leaching residue crude extract with liquid metal solvent at 200 to 600 Celsius to keep the indium and germanium in the crude extract dissolved in the liquid metal solvent, forming a mixed slurry containing liquid metal solution and solid impurity slag;

[0008] Step 102, thermal phase in-situ purification, the mixed slurry is placed in a first heating kettle and a second purification kettle with a thermal gradient, the temperature of the first heating kettle is higher than the temperature of the second purification kettle ; the difference in thermal conductivity between the liquid metal solution and the solid impurity slag drives the liquid metal solution to migrate to the second purification kettle, and the solid impurity slag is retained; the temperature of the second purification kettle is lowered below the solidification point of the liquid metal solvent, so that the liquid metal solution is directionally solidified, and the suspended particulate impurities are enriched in the last solidified liquid phase; the liquid phase is removed, and the solidified pure solid phase solvent in the second purification kettle is remelted to obtain an ultra-clean growth solution;

[0009] Step 103, chemical component calibration, analyzing the actual component ratio of indium and germanium in the ultra-clean growth solution; according to the difference between the actual component ratio and a target component ratio, pure indium material or pure germanium material is added 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;

[0010] Step 104, liquid phase epitaxial growth, the ultra-clean growth solution calibrated in step 103 is used as a growth solution, a single crystal seed crystal is introduced, and the temperature is lowered to make indium and germanium grow on the single crystal seed crystal to form an indium-germanium alloy single crystal.

[0011] Preferably, the liquid metal solvent is selected from pure gallium or gallium-based alloy, and the gallium-based alloy is gallium-indium alloy or gallium-tin alloy. Gallium or gallium-based alloy is used as the liquid metal solvent because it has high solubility for indium and germanium at the working temperature of step 101, and low solubility for the oxide and silicate components in the solid impurity slag.

[0012] Preferably, in step 102, the temperature of the first heating kettle is maintained at 300 to 500 , and the temperature of the second purification kettle is maintained at 30 to 100 , so as to establish a thermal gradient therebetween. Preferably, in step 102, the temperature of the second purification kettle is lowered below the solidification point of the liquid metal solvent by a cooling rate of 0.5 to 5

[0013] per hour; directional solidification is based on the solute partition law, so that the distribution coefficient of particulate impurities is much less than 1, thereby ensuring that particulate impurities are rejected by the solid-liquid interface of the grown pure solid phase solvent and enriched in the liquid phase.

[0014] ​​​Preferably, in step 103, the actual component ratio of indium and germanium in the ultra-clean growth solution is analyzed by using inductively coupled plasma atomic emission spectrometry or X-ray fluorescence spectrometry.

[0015] Preferably, in step 104, the temperature reduction is achieved by a precise temperature reduction program of 0.1 to 1 per hour.

[0016] Preferably, the method further comprises step 105, solvent regeneration, recovering the growth solution remaining in step 104 and returning it as a liquid metal solvent to step 101 for recycling.

[0017] Preferably, in step 104, the single crystal seed is a germanium single chip or a silicon single chip.

[0018] Preferably, in step 103, the target component ratio is determined according to the target alloy component x value of the indium-germanium alloy single crystal to be prepared, and the chemical formula of the indium-germanium alloy single crystal is .

[0019] Preferably, the method further comprises 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 calibrated in step 103 ; comparing the total concentration with a pre-set target total concentration ; when the total concentration is higher than the target total concentration , supplementing pure liquid metal solvent as a diluent to the ultra-clean growth solution calibrated in step 103, and the supplementing mass of the diluent is determined by the following relationship: , wherein is the current mass of the liquid metal solvent in the ultra-clean growth solution calibrated in step 103, and a total concentration calibrated solution is obtained; and step 104 is correspondingly modified as: step 104, liquid phase epitaxial growth, introducing a single crystal seed into the total concentration calibrated solution as a growth solution, and reducing the temperature to grow indium and germanium on the single crystal seed to form an indium-germanium alloy single crystal.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] 1. The present invention utilizes the same low-melting liquid metal medium to undertake two completely separate technical roles in the same process flow: first, as a selective extraction solvent at low temperature, used to prepare a liquid solution rich in target elements from industrial crude extract; then, without replacement, directly as a mother liquor for single crystal growth. This process architecture, which unifies solution preparation upstream with crystal growth downstream in a single mild non-aqueous, non-high-temperature molten phase system, establishes a continuous path from complex industrial raw materials to high-purity single crystal materials, changing the traditional process premise in the single crystal growth field that must rely on high-purity starting materials.

[0022] 2. Before the core step of single crystal growth (liquid phase epitaxy), a coordinated link of component analysis and component calibration is set. This link is designed with the deep understanding that upstream industrial crude extract has natural uncontrollable batch-to-batch fluctuations in chemical composition, which is fatal to the downstream preparation of alloy single crystals of specific components. The present invention actively samples and analyzes the liquid metal solution before growth, and based on the difference between the analysis results and the preset target components, precise physical feed adjustment is made, thereby constructing a diagnostic compensation process loop that cuts off the transmission path of raw material composition uncertainty to the consistency of the final single crystal product, making it possible to use industrial waste slag with composition fluctuations to repeatedly produce alloy single crystals of specific components.

[0023] 3. By introducing an in-situ purification mechanism based on thermodynamics and phase transition principles, the systematic defect of mechanical filtration means that cannot remove particulate impurities is systematically solved. This mechanism first uses the physical difference in thermal conductivity between liquid metal and solid slag to drive the non-contact migration of liquid metal solution to the purification area by applying a thermal gradient, achieving coarse separation with solid slag. Then, a controllable directional solidification process is started in the purification area, using the repelling effect of the liquid-solid phase interface on particulate impurities to systematically drive and enrich those heterogeneous nucleation centers that cause disordered crystal growth into the last solidified waste liquid. This ultra-clean solution preparation method, which relies entirely on thermal field control and phase transition laws rather than mechanical barriers, ensures that the crystal grows exclusively and orderly on the seed surface during the subsequent single crystal growth process. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 Process flow chart for the present invention's coordinated recovery and single crystal preparation;

[0025] Fig. 2 Comparison chart of total solution concentration and supersaturation index before and after total concentration calibration of the present invention;

[0026] Fig. 3The corresponding relationship diagram of the process core stage, key element material and control. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0028] The disclosed process for the synergistic recovery of indium and germanium from zinc leaching residue and the preparation of single crystals comprises four core stages in the overall technical framework. Firstly, low-temperature extraction is performed in step 101, using a liquid metal solvent to selectively dissolve the target metals in the raw material. Subsequently, hot-phase in-situ purification is performed in step 102, achieving physical purification through thermodynamic principles rather than mechanical filtration. Then, chemical component calibration is performed in step 103, accurately balancing the chemical composition of the purified solution. Finally, liquid-phase epitaxial growth is performed in step 104, using the physically pure and accurately composed solution to prepare target single crystals. Specifically, the low-temperature extraction in step 101 uses zinc leaching residue crude extract as the starting material. The crude extract is a complex mixture containing target products indium and germanium, as well as a large amount of solid impurity slag such as oxide and silicate components. To achieve the preliminary separation of target metals and impurity slag under mild conditions, a liquid metal solvent is introduced. The liquid metal solvent is preferably pure gallium or a gallium-based alloy, such as gallium-indium alloy or gallium-tin alloy. The selection of such solvents is based on the fact that they have high chemical solubility for indium and germanium in the low-temperature working interval of 200 to 600 °C, while the solubility of oxide, silicate and other solid impurity slag components is extremely low. In operation, after mixing the crude extract with the liquid metal solvent, it is kept at a preferred working temperature of, for example, 300 to 500 °C, 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, forming a mixed slurry containing liquid metal solution and solid impurity slag.

[0029] Subsequently, the mixed slurry enters the hot-phase in-situ purification stage in step 102. This step is used to remove micron or even nanometer-sized suspended particles that cannot be removed by conventional mechanical filtration. These particles are a source of interference that may cause unintended nucleation in subsequent single crystal growth. To remove these particles, a two-kettle thermodynamic separation design is used in this step. The mixed slurry is placed in a first heating kettle and a second purification kettle, and the temperature of the first heating kettle is controlled to be higher than that of the second purification kettle. The mixed slurry is heated in the first kettle to a temperature higher than the melting point of the liquid metal solvent, and then transferred to the second kettle. The temperature of the second kettle is controlled to be lower than the melting point of the liquid metal solvent, so that the liquid metal solvent in the second kettle is in a liquid state, while the solid impurity slag is in a solid state. The liquid metal solvent in the second kettle is then cooled to a temperature lower than the melting point of the liquid metal solvent, so that the liquid metal solvent in the second kettle is in a solid state, while the solid impurity slag is in a liquid state. , for example, maintained at 300 higher than the temperature of the second purification kettle , for example, maintained at 30 , so as to establish a controlled thermal gradient; based on the high thermal conductivity characteristics of the liquid metal solution and the low thermal conductivity characteristics of the solid impurity slag, using the property difference, the thermal gradient will drive the liquid metal solution to migrate to the second purification kettle, and most of the solid impurity slag will be retained in the first heating kettle due to the thermodynamic effect; after completing the thermal migration coarse separation, in order to remove the suspended particulate impurities entrained into the second purification kettle, this step further utilizes the phase change purification principle of directional solidification, and the specific operation is to reduce the temperature of the second purification kettle to below the solidification point of the liquid metal solvent at a slow cooling rate of 0.5 per hour; in this directional solidification process, according to the solute distribution law, those suspended particulate impurities with different physical and chemical properties have a distribution coefficient much less than 1 in the solid phase solvent, so they are repelled by the solid-liquid interface of the growing pure solid phase solvent and enriched in the last solidified liquid phase; when the solidification is close to completion, the last solidified liquid phase enriched with all particulate impurities is removed by physical means, and then the remaining solidified pure solid phase solvent in the second purification kettle is remelted, thereby obtaining an ultra-clean growth solution.

[0030] The thermal phase in-situ purification unit of step 102 is to establish and maintain a controllable temperature gradient field to drive the migration and separation of liquid and solid phases. The first heating kettle ( ) and the second purification kettle ( ) are thermodynamically coupled through a connecting channel with a specific geometric size. To achieve efficient separation and ensure sufficient retention of solid impurity slag, the effective thermal gradient between the two kettles is maintained in the range of , where is the difference between and , is the center point distance between the two kettle temperature sensors, and the migration time of the liquid metal solution under the driving of the thermal gradient is determined by calculating the heat transfer model of different viscosity slurries in advance. The migration retention time is set to be more than times of an empirical characteristic time to ensure that the liquid metal solution rich in indium germanium is fully transferred to the second purification kettle. The migration time is determined by monitoring the recovery rate of the liquid metal solution at the outlet of the first heating kettle to reach ​​​​​The time spent in the calibration of the thermal migration coarse separation method, which takes advantage of the inherent difference in thermal conductivity, circumvents the physical upper limit constraint on particle size that mechanical filtration suffers from; in the directional solidification purification step 102, the temperature of the second purification kettle is reduced at a rate of to below the solidification point of the liquid metal solvent, in order to accurately remove the last solidified liquid phase enriched with suspended particulate impurities; the judgment of the solidification percentage is based on real-time monitoring of the temperature of the solidification front by the thermocouple array and analysis of the phase transition enthalpy release curve: when the system temperature reaches the solidification point of the liquid metal solvent and begins to slowly cool down, the solidification endpoint is determined by calculating the cooling time corresponding to the when the total amount of solidification exothermic heat reaches the total phase transition enthalpy The solidification endpoint is determined, and immediately after the determination of the solidification endpoint, a non-contact inert gas high-pressure extrusion operation is started to extrude and collect the central region of the still liquid impurity-enriched liquid phase through a bottom impurity removal valve to an independent collection container; the start and stop of the impurity removal valve are based on real-time monitoring of the extruded liquid phase mass by a flow sensor to ensure that only the predetermined enriched liquid phase mass is removed; this procedure can reduce the concentration of particulate impurities to below the technical indicators that can be used for subsequent liquid phase epitaxial growth without introducing secondary pollution; after obtaining the ultra-clean growth solution, in order to solve the problem of chemical composition fluctuation of the raw material source, the process flow then performs step 103 of chemical component calibration; this step first requires accurate determination of the actual component ratio of indium and germanium in the ultra-clean growth solution, which can be achieved by mature analysis means in the art, such as inductively coupled plasma atomic emission spectrometry (ICP-AES) or X-ray fluorescence spectrometry (XRF); then, the measured actual component ratio is compared with a target component ratio, which is predetermined according to the target alloy component value in the target chemical formula of the indium-germanium alloy single crystal to be prepared; according to the difference between the actual component ratio and the target component ratio, pure indium material or pure germanium material is added to the ultra-clean growth solution until the ratio of indium and germanium in the ultra-clean growth solution is accurately adjusted to the target component ratio.

[0031] In some embodiments with higher requirements for growth kinetics, a step 103A of total concentration calibration can be added after step 103 and before step 104; this step aims to ensure that the saturation of the solution is within a pre-set growth window, and the operation is as follows: first, determine the total concentration of indium and germanium in the ultra-clean growth solution after step 103 calibration ; compare this with a pre-set target total concentration ; when the total concentration is found to be lower than the target total concentration, pure indium material is added to the ultra-clean growth solution until the total concentration of indium and germanium in the ultra-clean growth solution is adjusted to the target total concentration. higher than the target total concentration , indicating that the solution is supersaturated, at which point pure liquid metal solvent, i.e. the same solvent used in step 101, such as pure gallium, is added as diluent; the amount of diluent added is calculated by a certain relationship: , wherein, is the current amount of liquid metal solvent in the ultra-clean growth solution after calibration in step 103, is the measured total concentration, is the target total concentration, and the solution whose total concentration is also calibrated through this step; finally, step 104 of liquid phase epitaxial growth is performed; the ultra-clean growth solution after calibration in step 103 (or the total concentration calibrated solution after calibration in step 103A) is used as the final growth solution; in the growth solution, a single crystal seed crystal is introduced, which can be a germanium single chip or a silicon single chip; then, a precise cooling program of 0.1 to 1 per hour is started to slowly bring the growth solution to and maintain it at a slightly supersaturated state, and the indium and germanium atoms in the solution will orderly heterogeneously nucleate and epitaxially grow on the surface of the single crystal seed crystal, eventually forming an indium-germanium alloy single crystal with the target composition ; for the sake of process economy, the method can further include step 105 of solvent regeneration: the growth solution remaining after the end of step 104 is recovered and recycled as liquid metal solvent to step 101; the method including the solvent regeneration step 105 of step 104 recovers the remaining growth solution as liquid metal solvent and recycles it to step 101, to ensure the long-term stability of the solvent quality and the feasibility of recycling, the quality of the regenerated solvent is periodically controlled: after to batches of recycling, the non-target impurity elements (such as , , trace metal impurities from leaching residue) in the regenerated solvent must be analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES), and if the concentration of any non-target impurity element exceeds the preset control limit of , a deep purification process of the solvent is started, which includes an additional secondary directional solidification purification at an extremely low rate of to per hour to distribute the enriched impurities to the end solidification area of the solvent and remove them, ensuring that the purity of the regenerated solvent meets the strict requirements of semiconductor single crystal preparation for the purity of the starting material.

[0032] 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 in the center, which contains all the particulate impurities. Then, remelt the second purification vessel to 60°C. This yields a physically clean growth solution.

[0033] The ultraclean growth solution provides a prerequisite for subsequent chemical component calibration. Without the physical eradication of heterogeneous nucleation centers in step 102, any chemical calibration is meaningless. Then, step 103 is performed to analyze the ultraclean growth solution by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the actual component ratio of indium to germanium in the solution is measured to be 0.08:0.92, which corresponds to the chemical formula , which deviates from the target component ratio of . According to the deviation, a calculated amount of pure indium material is accurately added to the ultraclean growth solution and fully dissolved to adjust the ratio of indium to germanium in the solution to the target component ratio of 0.1:0.9. In this way, the thermal phase in step 102 is in-situ purified, and through thermal gradient migration and directional solidification phase transition, a solution free of heterogeneous nucleation centers is obtained, which provides an analyzable, adjustable, and homogeneous medium for the chemical component calibration in step 103. The analysis and compensation in step 103 further make the solution have an accurately controlled chemical component. Finally, in step 104, the calibration ultraclean growth solution, which is free of particulate interference and has an accurate chemical component, is used for liquid phase epitaxial growth. A piece of germanium single chip is introduced as a single crystal seed, and a precise cooling program of 0.2 per hour is started. Since there is no particulate interference causing spontaneous nucleation in the solution and the indium-germanium chemical component is accurately controlled, only indium and germanium will have ordered epitaxial growth on the single crystal seed, and finally a high-quality indium-germanium alloy single crystal with the target alloy component is obtained.

[0034] Example 2: This example compares the effects of three process methods in treating the same batch of contaminated and component deviated zinc leaching residue crude extract. The target of this batch of raw material is to prepare alloy single crystal. Three groups are set up for the test, all using the same batch of zinc leaching residue crude extract. The batch of raw material is pre-detected to contain high concentration of sub-micron silicate particles, with a count of more than particles / mL, and its inherent indium-germanium mass ratio is 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 is the control group D1, which simulates the conventional mechanical filtration process. This group performs step 101 of low-temperature extraction, and then uses a 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.

[0035] 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.

[0036] Table 1: Effects of different purification and calibration processes on single crystal growth results

[0037]

[0038] 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.

[0039] 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.

[0040] Example 3: A comparative example D3 is set up, whose process flow is compared with the inventive sample group S1 in Example 2, the difference is that: the comparative example D3 uses a conventional hydrometallurgical process route instead of the step 101 (low-temperature liquid metal extraction) and step 102 (hot phase in-situ purification) of the present application, and then attempts to perform the step 104 of liquid phase epitaxial growth; the comparative example D3 uses the same starting material as the S1 sample group in Example 2, i.e. 1 kg of the same batch of zinc leaching residue crude extract, which contains a high concentration of sub-micron silicate particles, and the mass ratio of indium to germanium is determined to be 0.15:0.85; the process flow of the comparative example D3 first performs a hydrometallurgical purification step: instead of step 101 of the present application, 1 kg of crude extract is treated by a conventional hydrometallurgical process; the specific operation is to place the crude extract in an acid-resistant reaction kettle, add 5 L of 2 M sulfuric acid solution, and stir and leach at 80 for 4 hours; the leaching solution is filtered by pressure filtration, and the filtrate is transferred to a multi-stage extraction tank for selective extraction and stripping using P204 extractant to separate indium and germanium; the stripping solution is combined, and the indium and germanium are co-precipitated as mixed hydroxide by adjusting the pH value to 3.5; the precipitate is filtered, washed, and calcined at 600 for 2 hours, finally obtaining 45 g of indium-germanium mixed oxide powder; this process produces about 6.2 L of high-salinity acidic wastewater.

[0041] Then, an attempt is made to prepare a growth solution: all 45 g of mixed oxide powder obtained in the above step is added to 5 kg of pure gallium liquid metal solvent (the same solvent mass as the S1 sample group), and heated to 450 (the same extraction temperature as the S1 sample group), and stirred for 2 hours; at 450 It is observed that the indium-germanium mixed oxide powder is almost insoluble in the liquid gallium solvent, but is highly dispersed in the form of solid particles in the gallium solvent, forming an uneven suspension slurry; this high-temperature suspension slurry is transferred to a liquid phase epitaxial growth furnace, a (100) crystal direction germanium single chip is introduced as a single crystal seed crystal, and the same precise cooling program of 0.5 per hour as the S1 sample group is performed; after the growth is completed, the seed crystal is taken out, and it is observed that the surface of the seed crystal has not undergone any epitaxial growth of indium-germanium alloy; the residue in the crucible is analyzed, which is still a physical mixture of solid gallium metal and undissolved indium-germanium mixed oxide powder; the comparative test results are summarized in Table 2.

[0042] Table 2: Comparison table of the present application route (S1) and the conventional hydrometallurgical route (D3)

[0043]

[0044] 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.

[0045] Example 4: This example combines Figs. 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: Fig. 1 As 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.

[0046] like Fig. 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. Fig. 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 heat preservation forms a mixed slurry, the hot phase is purified in place by removing heterogeneous nucleation centers, directional solidification purification, and thermal gradient migration separation, the chemical component calibration stage includes total concentration calibration, supplementary pure metal deployment, analysis of actual component ratio, and liquid phase epitaxial growth stage, using a precise cooling program, introducing a single crystal seed crystal, and using calibrated ultra-clean solution, ultimately realizing the preparation of high-quality indium-germanium alloy single crystals. The bottom layer of the roadmap summarizes the key elements required to implement the above process and vertically corresponds to the top stage: among them, the key material module includes zinc leaching slag crude extract, liquid metal solvent gallium-based, and single crystal seed crystal germanium / silicon, which vertically corresponds to the low-temperature extraction stage, and the analysis and control module includes component analysis ICP / XRF, thermal gradient control, and precise cooling rate control, which vertically corresponds to the chemical component calibration stage.

[0047] Example 5: This example records the key process parameter calibration and application procedures for preparing alloy single crystals with a target alloy component of ; first, the target total concentration required in step 104 is calibrated, a series of test melts are prepared, each containing 100 g of pure gallium liquid metal solvent, and 1 g of indium-germanium alloy material mixed in advance according to a mass ratio of 0.3:0.7 is added to each test melt, and the mass increases from 1 g to 10 g; the freezing point, i.e., the liquidus temperature , of each test melt is determined by differential scanning calorimetry (DSC); when the alloy material addition amount is 5.0 g, the liquidus temperature is 451.2 ; when the addition amount is 5.5 g, is 462.5 ; based on this data, the initial growth temperature of step 104 is set to 460 , and the corresponding target total concentration is determined to be 5.4 g of alloy per 100 g of gallium, i.e., the total solute mass fraction is 5.12%; then, the process parameters of step 102 are calibrated; using the same contaminated crude extract raw material as in Example 2, three gradient test groups are set: test group A sets to 450 , to 60 ; test group B sets to 450 , to 150 (higher than the upper limit of 100 ); test group C sets to 250 (lower than the lower limit of 300 ), to 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.

[0048] 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.

[0049] 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.

[0050] 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 the synergistic recovery of indium and germanium from zinc leach residue and production of single crystals, characterized by, The method comprises: Step 101, low temperature extraction, the zinc leaching residue crude extract is mixed with a liquid metal solvent at 200 to 600 degrees Celsius to dissolve indium and germanium in the crude extract into the liquid metal solvent to form a mixed slurry comprising a liquid metal solution and solid impurity slag; Step 102, hot phase in-situ purification, the mixed slurry is placed in a first heating kettle and a second purification kettle with a thermal gradient, the temperature of the first heating kettle is higher than the temperature of the second purification kettle ; 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 kettle and to make the solid impurity slag stay; the temperature of the second purification kettle is lowered below the solidification point of the liquid metal solution, so that the liquid metal solution is directionally solidified, and the suspended particulate impurities are enriched in the last solidified liquid phase; the liquid phase is removed, and the solidified pure solid phase solution in the second purification kettle is remelted to obtain an ultra-clean growth solution; ; 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 kettle and to make the solid impurity slag stay; the temperature of the second purification kettle is lowered below the solidification point of the liquid metal solution, so that the liquid metal solution is directionally solidified, and the suspended particulate impurities are enriched in the last solidified liquid phase; the liquid phase is removed, and the solidified pure solid phase solution in the second purification kettle is remelted to obtain an ultra-clean growth solution; Step 103, chemical component calibration, analyzing the actual component ratio of indium and germanium in the ultraclean growth solution; according to the difference between the actual component ratio and a target component ratio, supplementing pure indium material or pure germanium material to the ultraclean growth solution to adjust the ratio of indium and germanium in the ultraclean growth solution to the target component ratio; Step 104, liquid phase epitaxial growth, taking the ultraclean growth solution calibrated in step 103 as a growth solution, introducing a single crystal seed crystal, and cooling to make indium and germanium grow on the single crystal seed crystal to form an indium-germanium alloy single crystal; In addition, the liquid metal solvent is selected from pure gallium or a gallium-based alloy, and the gallium-based alloy is a gallium-indium alloy or a gallium-tin alloy. The reason for using gallium or a gallium-based alloy as the liquid metal solvent is that gallium or a gallium-based alloy has high solubility for indium and germanium at the working temperature in step 101, and has low solubility for oxide and silicate components in the solid impurity slag.

2. A process for the synergic recovery of indium and germanium and preparation of single crystals from zinc leaching residue according to claim 1, characterized in that, In step 102, the temperature of the first heating vessel is maintained at 300 to 500 Celsius. In step 104, the temperature of the second heating vessel is maintained at 30 to 100 Celsius. to establish a thermal gradient between the two.

3. A process for the simultaneous recovery of indium and germanium and preparation of single crystals from zinc leaching residue 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 at a rate of 0.5 to 5 °C per hour; directional solidification, based on the solute partition law, causes the distribution coefficient of the particulate impurities to be much less than 1.

4. The process of claim 1, wherein the process is characterized in that, In step 103, the actual component ratio of indium and germanium in the ultraclean growth solution is analyzed by using inductively coupled plasma atomic emission spectrometry or X-ray fluorescence spectrometry.

5. The process of claim 1, wherein the process is characterized in that, In step 104, the temperature is lowered by a precision temperature lowering program of 0.1 to 1 per hour.

6. The process of claim 1, wherein the process is characterized by, The method further comprises step 105, solvent regeneration, recovering the growth solution remaining in step 104 and returning it to step 101 as a liquid metal solvent for recycling.

7. A process for the simultaneous recovery of indium and germanium and preparation of single crystals from zinc leaching residue 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.

8. A process for the simultaneous recovery of indium and germanium and preparation of single crystals from zinc leaching residue according to claim 1, characterized in that, In step 103, the target component ratio is determined according to a target alloy component x value of the indium-germanium alloy single crystal to be prepared, the chemical formula of the indium-germanium alloy single crystal being .

9. The process of claim 1, wherein the process is characterized in that, The method further comprises a step 103A, total concentration calibration, determining the total concentration of indium and germanium in the ultra-clean growth solution calibrated in step 103 ; comparing the total concentration with a preset target total concentration ; when the total concentration is higher than the target total concentration , supplementing the ultra-clean growth solution calibrated in step 103 with pure liquid metal solvent as a diluent, the supplementing mass of the diluent is determined by the following relationship: , wherein, is the current mass of the liquid metal solvent in the ultra-clean growth solution calibrated in step 103, and a total concentration calibration solution is obtained; and step 104 is correspondingly modified as: step 104, liquid phase epitaxial growth, taking the total concentration calibration solution as a growth solution, introducing a single crystal seed crystal, and cooling to grow indium and germanium on the single crystal seed crystal to form an indium-germanium alloy single crystal.

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