Aluminum-silicon solid waste dealkalization and resource system based on lattice distortion

Abstract

The present application relates to the technical field of comprehensive utilization of solid waste, and particularly relates to an aluminum-silicon solid waste dealkalization and resource system based on lattice distortion, comprising: a dealkalization control module, comprising a pulping unit for converting aluminum-silicon solid waste into a permeable system; a resource recovery module, comprising a separation unit for separating dealkalized solid phase from alkali-containing liquid phase after dealkalization; a dealkalization determination module for determining whether the dealkalization completeness of aluminum-silicon solid waste meets the requirements according to the dealkalization completion rate; a variable pressure mechanism construction module for determining whether to construct a structure disturbance mechanism and determining the alternating pressure difference amplitude according to the alkali metal ion concentration in the leaching solution of the dealkalized solid phase; and a dealkalization environment adjustment module for determining whether to add a low-concentration weak acid solution according to the net release rate of alkali metal ions in the dealkalization process. The present application improves the dealkalization completeness of aluminum-silicon solid waste.

Description

Technical Field

[0001] This invention relates to the field of solid waste comprehensive utilization technology, and in particular to an aluminum-silicon solid waste dealkali removal and resource recovery system based on lattice distortion. Background Technology

[0002] In the fields of industrial solid waste resource utilization and green metallurgy, the dealkali removal and resource utilization system for aluminum-silicon solid waste has become an important technical means to achieve the reduction of bulk solid waste and the recovery of valuable components. Because the Al-O and Si-O tetrahedra in aluminum-silicon solid waste form stable mullite, quartz, and other crystalline phase structures, alkali metal ions are usually embedded within the crystal lattice to form stable chemical bonds. Therefore, the dealkali removal efficiency directly affects the purity of subsequent aluminum extraction products and production energy consumption. When relying on traditional acid-alkali leaching or sintering processes, it is often difficult to effectively break the bonding relationship between alkali metals and the aluminum-silicon framework at the crystal lattice level, easily leading to incomplete dealkali removal, excessive alkali content in the product, or increased waste discharge, thereby weakening the resource utilization value of aluminum-silicon solid waste. Although existing treatment technologies have achieved partial aluminum-silicon separation, they mostly focus on the extraction of valuable metals or the desiliconization stage, with insufficient support for the deep removal of alkali metals and the lattice distortion induction mechanism, resulting in generally low dealkali removal efficiency. Subsequent treatment of alkali-containing residues indirectly increases carbon emissions. Therefore, there is an urgent need for an aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion, which can induce lattice deformation and defects through directional perturbation, reduce the bonding strength of alkali metals, and achieve efficient dealkali removal and full-component resource utilization of aluminum-silicon solid waste.

[0003] Chinese Patent Publication No. CN104803403A discloses an acid-base combined process for pre-desiliconizing and extracting alumina from coal-based solid waste, comprising: sulfuric acid acidolysis: the coal-based solid waste is mixed evenly with concentrated sulfuric acid, and then acidolyzed and solidified at a temperature of 120–500℃; high-temperature roasting decomposition: the acid-treated and solidified coal-based solid waste is roasted at a temperature of 900–1200℃ for 0.1–30 min without the addition of a reducing agent to obtain roasted sand and sulfur-containing flue gas, the sulfur-containing flue gas is collected and used to make acid for recycling back to the acidolysis process; atmospheric pressure low-temperature alkaline leaching desiliconization: the roasted sand is treated with sodium hydroxide with a Na2O concentration of 50–150 g / L. Silicon is leached from the solution at a solid-liquid mass-to-volume ratio of 1:3 to 1:20, a leaching temperature of 50 to 100℃, and a leaching time of 30 to 240 min. The leaching solution contains silicon and high-alumina slag. Aluminum is then extracted by pressurized high-temperature alkaline leaching: the high-alumina slag obtained in the first step is leached with a sodium hydroxide solution with a Na₂O concentration of 150 to 300 g / L, at a solid-liquid mass-to-volume ratio of 1:3 to 1:20, a molecular weight ratio of αk1 to 2, and lime addition of 0 to 15% of the high-alumina slag mass. The leaching temperature is 150 to 300℃, and the leaching time is 15 to 120 min. After leaching, the solution is filtered, and the resulting sodium aluminate solution is purified, seeded, and calcined to produce alumina. Therefore, it can be seen that the acid-base combined process for pre-desiliconizing and extracting alumina from coal-based solid waste has problems such as insufficient leaching power under normal pressure alkali leaching and pressurized alkali leaching conditions, and the high concentration of sodium ions in the alkali leaching solution easily triggering the re-adsorption of residual alkali metals, resulting in incomplete dealkali removal from aluminum-silicon solid waste. Summary of the Invention

[0004] To address this, the present invention provides a system for dealkali removal and resource utilization of aluminum-silicon solid waste based on lattice distortion, which overcomes the problems in the prior art where insufficient leaching power under normal pressure and pressurized alkali leaching conditions, and the high concentration of sodium ions in the alkali leaching solution easily triggers the re-adsorption of residual alkali metals, resulting in incomplete dealkali removal of aluminum-silicon solid waste.

[0005] To achieve the above objectives, this invention provides a system for dealkali removal and resource utilization of aluminum-silicon solid waste based on lattice distortion, comprising: The dealkali control module includes a pulping unit for converting aluminum-silicon solid waste into a permeable system, a pressurized permeation unit connected to the pulping unit for introducing acidic gas into the permeable system under controlled pressure, and a reaction unit connected to the pressurized permeation unit for causing lattice distortion in the aluminum-silicon solid waste through the acidic gas in a closed environment to complete the dealkali removal. The resource recovery module is connected to the dealkali control module, and includes a separation unit for separating the dealkali solid phase and the alkali-containing liquid phase after dealkali removal, and a recovery unit connected to the separation unit for recycling the dealkali solid phase and the alkali-containing liquid phase to obtain metal resources and alkali metal salts respectively. The dealkali determination module, which is connected to the resource recycling module, is used to determine whether the dealkali removal of aluminum-silicon solid waste meets the requirements based on the dealkali removal completion rate. The pressure change mechanism construction module is connected to the dealkali control module and the dealkali determination module respectively, and is used to determine whether to construct a structural disturbance mechanism and determine the amplitude of the alternating pressure difference based on the concentration of alkali metal ions in the leachate of the dealkali solid phase. The dealkali removal environment adjustment module is connected to the dealkali removal control module and the pressure swing mechanism construction module, respectively, and is used to determine whether to add a low-concentration weak acid solution based on the net release rate of alkali metal ions during the dealkali removal process.

[0006] Furthermore, the dealkali determination module determines that the dealkali removal completion rate meets the requirements when the dealkali removal completion rate is greater than the preset completion rate; The dealkali determination module determines that the completeness of dealkali removal of aluminum-silicon solid waste does not meet the requirements when the dealkali removal completion rate is less than or equal to the preset completion rate.

[0007] Furthermore, in response to the condition that the completeness of dealkali removal from the aluminum-silicon solid waste does not meet the requirements, the pressure-switching mechanism construction module determines whether the residual amount of alkali metal in the dealkali solid phase meets the requirements based on the concentration of alkali metal ions in the leachate of the dealkali solid phase.

[0008] Furthermore, the pressure swing mechanism construction module determines that the residual amount of alkali metal in the dealkali solid phase meets the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is less than or equal to a preset first concentration. The pressure swing mechanism construction module determines that the residual alkali metal in the dealkali solid phase does not meet the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset first concentration.

[0009] Furthermore, the pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkalized solid phase is greater than the preset first concentration and less than or equal to the preset second concentration, and constructs a structural disturbance mechanism and increases the amplitude of the alternating pressure difference. The pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset second concentration, initially determines that the release stability of the bound alkali does not meet the requirements, and determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali process.

[0010] Furthermore, the construction of the structural disturbance mechanism and the increase of the alternating pressure difference amplitude include: The pressure differential mechanism construction module is used to apply different pressures to opposite ends of the reaction space of the reaction unit to form a pressure difference and construct a basic pressure differential field. The pressure variation mechanism construction module is used to superimpose periodic pressure disturbances on the basic pressure difference field to form an alternating pressure difference field; The voltage switching mechanism module is used to suppress the desorption and resorption of alkali metal ions by increasing the amplitude of the alternating voltage difference.

[0011] Furthermore, the increase in the amplitude of the alternating pressure difference is determined by the difference between the concentration of alkali metal ions in the leachate of the dealkalized solid phase and the preset first concentration.

[0012] Furthermore, in response to the condition that the concentration of alkali metal ions in the leachate of the alkali-degrading solid phase is greater than the preset second concentration, the dealkali-degrading environment adjustment module determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali-degrading process.

[0013] Furthermore, the dealkali removal environment adjustment module determines that the release stability of the bound alkali meets the requirements when the net release rate of alkali metal ions during the dealkali removal process is greater than the preset release rate. The dealkali removal environment adjustment module responds to the fact that the net release rate of alkali metal ions during the dealkali removal process is less than or equal to the preset release rate, determines that the release stability of the bound alkali does not meet the requirements, and adds a low-concentration weak acid solution.

[0014] Furthermore, the concentration of the low-concentration weak acid solution is determined by the difference between the net release rate of alkali metal ions during the dealkalization process and the preset release rate.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The system of the present invention, by setting up a dealkali control module, a resource recovery module, a dealkali judgment module, a pressure differential mechanism construction module, and a dealkali environment adjustment module, determines whether the dealkali completeness of aluminum-silicon solid waste meets the requirements based on the dealkali completion rate. Since the aluminum-silicon framework has a high specific surface area and ion exchange activity after dealkali treatment, there may be incompletely removed metal impurities or residual alkali metals in the solid phase, directly affecting the purity and usability of the recovered metals. By determining the dealkali completeness of the aluminum-silicon solid waste, the reliability of the recovery process's ability to remove metal impurities can be quantified, and potentially insufficient dealkali areas can be identified. Based on the alkali metal ion concentration in the leachate of the dealkali-treated solid phase, it is determined whether to construct a structural disturbance mechanism and adjust the alternating pressure differential amplitude. Because during the dealkali treatment process, the pore structure and surface of the solid phase particles... Active sites may lead to the re-adsorption or local concentration retention of alkali metal ions, making it difficult for static leaching to completely remove residual alkali metals. By constructing a structural perturbation mechanism and increasing the amplitude of alternating pressure difference, the material exchange efficiency at the solid-liquid interface can be enhanced, promoting the migration and release of residual alkali metal ions on the surface and in the pores of solid particles, thus reducing the amount of residual alkali metals. The addition of a low-concentration weak acid solution is determined based on the net release rate of alkali metal ions during the dealkali removal process. Since alkali metal ions on the surface active sites and in the pores of the solid phase are easily re-adsorbed under changes in concentration gradient or temperature fluctuations, the net release rate fluctuates. By adding a low-concentration weak acid solution, a weak dissolution layer can be formed to increase the local solubility of iron and aluminum ions to occupy the surface active sites, effectively inhibiting the re-adsorption of alkali metal ions, ensuring the stability of the continuous release of bound alkali, and improving the completeness of dealkali removal from aluminum-silicon solid waste.

[0016] Furthermore, the system described in this invention determines whether the completeness of dealkali removal from aluminum-silicon solid waste meets the requirements by setting a preset completion rate. Since the aluminum-silicon framework has a high specific surface area and ion exchange activity after dealkali removal, there may be incompletely removed metal impurities or residual alkali metals in the solid phase, which directly affects the purity and usability of the recovered metals. By determining the completeness of dealkali removal from aluminum-silicon solid waste, the reliability of the recycling process's ability to remove metal impurities can be quantified, and potential areas of insufficient dealkali removal can be identified, further improving the completeness of dealkali removal from aluminum-silicon solid waste.

[0017] Furthermore, the system of the present invention determines whether to construct a structural disturbance mechanism and adjusts the amplitude of alternating pressure difference by setting a preset first concentration and a preset second concentration. Since the pore structure and surface active sites of solid particles may lead to the re-adsorption or local concentration retention of alkali metal ions during the dealkali removal process, static leaching is difficult to completely remove residual alkali metals. By constructing a structural disturbance mechanism and increasing the amplitude of alternating pressure difference, the material exchange efficiency of the solid-liquid interface can be enhanced, promoting the migration and release of residual alkali metal ions on the surface and in the pores of solid particles, reducing the amount of residual alkali metals, and further improving the completeness of dealkali removal from aluminum-silicon solid waste.

[0018] Furthermore, the system of the present invention determines the addition of a low-concentration weak acid solution by setting a preset release rate. Since alkali metal ions in the active sites and pores of the solid phase are easily re-adsorbed under changes in concentration gradient or temperature fluctuations, causing fluctuations in the net release rate, the addition of a low-concentration weak acid solution can form a weak dissolution layer to increase the local solubility of iron and aluminum ions to occupy the active sites on the surface, effectively suppressing the re-adsorption of alkali metal ions, ensuring the stability of the continuous release of bound alkali, and further improving the completeness of alkali removal from aluminum-silicon solid waste. Attached Figure Description

[0019] Figure 1 This is an overall structural block diagram of the aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion, according to an embodiment of the present invention. Figure 2 This is a flowchart illustrating the process of determining the completeness of alkali removal from aluminum-silicon solid waste using a lattice distortion-based system for dealkali removal and resource recovery in an embodiment of the present invention. Figure 3 This is a flowchart illustrating the process of determining whether to construct a structural disturbance mechanism and determining the amplitude of alternating pressure difference in an aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion, as described in an embodiment of the present invention. Figure 4 This is a flowchart illustrating the process of determining whether to add a low-concentration weak acid solution in an aluminum-silicon solid waste dealkali removal and resource recovery system based on lattice distortion, as described in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0021] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] Please see Figure 1 As shown, it is an overall structural block diagram of the aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to an embodiment of the present invention.

[0023] This invention discloses a system for dealkali removal and resource utilization of aluminum-silicon solid waste based on lattice distortion, comprising: The dealkali control module includes a pulping unit for converting aluminum-silicon solid waste into a permeable system, a pressurized permeation unit connected to the pulping unit for introducing acidic gas into the permeable system under controlled pressure, and a reaction unit connected to the pressurized permeation unit for causing lattice distortion in the aluminum-silicon solid waste through the acidic gas in a closed environment to complete the dealkali removal. The resource recovery module is connected to the dealkali control module, and includes a separation unit for separating the dealkali solid phase and the alkali-containing liquid phase after dealkali removal, and a recovery unit connected to the separation unit for recycling the dealkali solid phase and the alkali-containing liquid phase to obtain metal resources and alkali metal salts respectively. The dealkali determination module, which is connected to the resource recycling module, is used to determine whether the dealkali removal of aluminum-silicon solid waste meets the requirements based on the dealkali removal completion rate. The pressure change mechanism construction module is connected to the dealkali control module and the dealkali determination module respectively, and is used to determine whether to construct a structural disturbance mechanism and determine the amplitude of the alternating pressure difference based on the concentration of alkali metal ions in the leachate of the dealkali solid phase. The dealkali removal environment adjustment module is connected to the dealkali removal control module and the pressure swing mechanism construction module, respectively, and is used to determine whether to add a low-concentration weak acid solution based on the net release rate of alkali metal ions during the dealkali removal process.

[0024] Specifically, the aluminum-silicon solid waste includes red mud, high-alkali industrial residues containing sodium aluminum silicate phase, high-alkali aluminum silicate metallurgical dust and sludge, and strongly alkaline industrial solid waste with an aluminum-silicon framework and containing bound alkali.

[0025] Specifically, the process of converting aluminum-silicon solid waste into a permeable system involves mixing the aluminum-silicon solid waste with a liquid medium at a preset solid-liquid ratio and homogenizing and stirring it to fully disperse the solid waste particles in the liquid phase and form a slurry system with interconnected pore structures.

[0026] Specifically, acidic gases include CO2 and SO2.

[0027] Specifically, the process of dealkalizing aluminum-silicon solid waste by causing lattice distortion through the action of acidic gases involves CO2 and SO2 under controlled pressure conditions breaking through the liquid film and capillary resistance on the surface of solid waste particles in a dissolution-permeation coupling manner to enter the pore-interface reaction zone. In this process, CO2 and SO2 undergo hydration in the liquid phase to form H2CO3 and HSO3, respectively. - The generated H + Weak acid anions replace Na+ in the aluminosilicate framework for charge compensation through proton exchange and coordination competition. + and K + Sites that disrupt AlO4 -The local charge balance of the tetrahedral structure weakens the coordination stability of the Si-O-Al bonds, causing local lattice distortion, pore structure relaxation, and in-situ reconstruction in the alkali-containing mineral phase, thus promoting Na + and K + Alkali metal ions detach from the solid-phase framework and migrate into the liquid phase.

[0028] Specifically, the lattice distortion process can be verified by X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area and pore volume measurement. X-ray diffraction is used to detect parameter changes and structural distortions in aluminosilicate framework lattices. Fourier transform infrared spectroscopy is used to reflect the coordination environment of alkali metal ions or Al / O / Si atoms in the aluminum-silicon framework. Specific surface area and pore volume measurements are used to detect the formation of reactive pore structures and the degree of framework relaxation within the aluminum-silicon solid waste skeleton.

[0029] Specifically, the alkali metal ions in the leachate of the dealkalized solid phase include sodium ions and potassium ions, with sodium ions being the preferred embodiment.

[0030] Specifically, the process of separating the dealkali-removed solid phase from the alkali-containing liquid phase involves separating the dealkali-removed solid phase from the alkali-containing liquid phase in the solid-liquid mixture after the dealkali reaction is completed, under the action of gravity, filtration, and centrifugation.

[0031] Specifically, the process of recovering and utilizing the dealkali-treated solid phase and the alkali-containing liquid phase to obtain metal resources and alkali metal salts respectively involves subjecting the separated dealkali-treated solid phase to magnetic separation and reduction roasting-magnetic separation to recover iron resources, and further extracting aluminum or preparing aluminum-based materials from the aluminum or aluminum-silicon phase in the remaining solid phase through acid leaching or alkali leaching; and subjecting the alkali-containing liquid phase to impurity removal, concentration, and salt separation treatment to reduce the Na content in the liquid phase. + and K + Alkali metal ions are converted into corresponding alkali metal salts and then recovered through crystallization.

[0032] Specifically, the metal resources are iron resources, aluminum resources, and aluminum-based materials.

[0033] Specifically, the alternating pressure difference amplitude is the difference between the maximum and minimum pressure values ​​applied to the permeable system of aluminum-silicon solid waste during the dealkali reaction process.

[0034] Specifically, the weak acid can be acetic acid, citric acid, or lactic acid, with acetic acid being the preferred embodiment.

[0035] In implementation, the system of this invention includes a dealkali control module, a resource recovery module, a dealkali judgment module, a pressure differential mechanism construction module, and a dealkali environment adjustment module. It judges whether the dealkali removal completeness of aluminum-silicon solid waste meets the requirements based on the dealkali removal completion rate. Because the aluminum-silicon framework has a high specific surface area and ion exchange activity after dealkali removal, there may be incompletely removed metal impurities or residual alkali metals in the solid phase, directly affecting the purity and usability of the recovered metals. By judging the dealkali removal completeness of the aluminum-silicon solid waste, the reliability of the recovery process's ability to remove metal impurities can be quantified, and potentially insufficient dealkali removal areas can be identified. Based on the alkali metal ion concentration in the leachate of the dealkali-removed solid phase, it determines whether to construct a structural disturbance mechanism and adjust the alternating pressure differential amplitude. During the dealkali removal process, the pore structure and surface active sites of the solid phase particles may lead to… Static leaching is insufficient to completely remove residual alkali metals due to re-adsorption or localized concentration retention of alkali metal ions. By constructing a structural perturbation mechanism and increasing the amplitude of alternating pressure difference, the material exchange efficiency at the solid-liquid interface can be enhanced, promoting the migration and release of residual alkali metal ions on the surface and in the pores of solid particles, thereby reducing the amount of residual alkali metals. The addition of a low-concentration weak acid solution is determined based on the net release rate of alkali metal ions during the dealkali removal process. Since alkali metal ions on the active sites and in the pores of the solid phase are easily re-adsorbed under changes in concentration gradient or temperature fluctuations, causing fluctuations in the net release rate, the addition of a low-concentration weak acid solution can form a weak dissolution layer, increasing the local solubility of iron and aluminum ions to occupy the surface active sites, effectively inhibiting the re-adsorption of alkali metal ions, ensuring the stability of the continuous release of bound alkali, and improving the completeness of dealkali removal from aluminum-silicon solid waste.

[0036] Please continue reading. Figure 2 As shown, it is a logic flowchart of the process for determining the completeness of dealkali removal of aluminum-silicon solid waste in an aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to an embodiment of the present invention.

[0037] Specifically, the dealkali determination module determines that the dealkali removal of aluminum-silicon solid waste meets the requirements when the dealkali removal completion rate is greater than the preset completion rate. The dealkali determination module determines that the completeness of dealkali removal of aluminum-silicon solid waste does not meet the requirements when the dealkali removal completion rate is less than or equal to the preset completion rate.

[0038] Understandably, in the lattice distortion-based aluminum-silicon solid waste dealkali removal and resource utilization system, the dealkali removal completion rate is used to characterize the completeness of dealkali removal in aluminum-silicon solid waste. The core logic is to transform the actual execution effect of the dealkali removal process into a quantifiable completion rate indicator. By comparing it with the preset completion rate, it is determined whether the dealkali removal process has achieved the expected goal, thus providing a quantitative basis for judging whether the completeness of dealkali removal in aluminum-silicon solid waste meets the requirements. The preset completion rate can be set according to the actual working conditions. The setting of the preset completion rate aims to ensure the dealkali removal effect and practicality of aluminum-silicon solid waste. Optionally, the preset completion rate is determined through a limited number of experiments by evaluating the dealkali removal effect of different dealkali removal completion rates on aluminum-silicon solid waste. The determined preset completion rate should be neither too small nor cause excessive interference to the dealkali removal reaction process of aluminum-silicon solid waste. For example, the preset completion rate is generally selected in the range of [86%, 90%].

[0039] Preferably, the preset completion rate is 88% in the preferred embodiment.

[0040] Specifically, the dealkali removal completion rate is the ratio of the difference between the total alkali content in the original aluminum-silicon solid waste and the alkali content in the dealkali-removed solid phase to the total alkali content in the original aluminum-silicon solid waste.

[0041] In practice, the system described in this invention determines whether the completeness of dealkali removal from aluminum-silicon solid waste meets the requirements by setting a preset completion rate. Since the aluminum-silicon framework has a high specific surface area and ion exchange activity after dealkali removal, there may be incompletely removed metal impurities or residual alkali metals in the solid phase, which directly affects the purity and usability of the recovered metals. By determining the completeness of dealkali removal from aluminum-silicon solid waste, the reliability of the recycling process's ability to remove metal impurities can be quantified, potential areas of insufficient dealkali removal can be identified, and the completeness of dealkali removal from aluminum-silicon solid waste can be further improved.

[0042] Please continue reading. Figure 3 As shown, it is a flowchart of the process of determining whether to construct a structural disturbance mechanism and determining the amplitude of alternating pressure difference in the aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to an embodiment of the present invention.

[0043] Specifically, in response to the condition that the completeness of dealkali removal from the aluminum-silicon solid waste does not meet the requirements, the pressure-switching mechanism construction module determines whether the residual amount of alkali metal in the dealkali solid phase meets the requirements based on the concentration of alkali metal ions in the leachate of the dealkali solid phase.

[0044] Specifically, the pressure swing mechanism construction module determines that the residual amount of alkali metal in the dealkali solid phase meets the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is less than or equal to a preset first concentration. The pressure swing mechanism construction module determines that the residual alkali metal in the dealkali solid phase does not meet the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset first concentration.

[0045] Specifically, the pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkalized solid phase is greater than the preset first concentration and less than or equal to the preset second concentration, by constructing a structural disturbance mechanism and increasing the amplitude of the alternating pressure difference. The pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset second concentration, initially determines that the release stability of the bound alkali does not meet the requirements, and determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali process.

[0046] It is understandable that the preset first concentration is less than the preset second concentration, and the three intervals divided by the preset first and second concentrations correspond to three different scenarios: The first interval is when the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase is less than or equal to the preset first concentration. The corresponding situation is: the residual amount of alkali metal in the dealkali-treated solid phase is determined to meet the requirements. The second range is where the concentration of alkali metal ions in the leachate of the dealkali-removed solid phase is greater than the preset first concentration and less than or equal to the preset second concentration. The corresponding situation is that during the dealkali removal process, the pore structure and surface active sites of the solid phase particles may cause the re-adsorption of alkali metal ions or local concentration retention, making it difficult for static leaching to completely remove residual alkali metals. The third interval is when the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase is greater than the preset second concentration. The corresponding situation is that alkali metal ions in the active sites and pores on the solid phase surface are easily re-adsorbed under changes in concentration gradient or temperature fluctuations, causing fluctuations in the net release rate.

[0047] Understandably, in the lattice distortion-based dealkali treatment and resource recovery system for aluminum-silicon solid waste, the residual alkali metal content in the dealkali-treated solid phase is characterized by preset first and second concentrations. The core logic is to transform the determination of alkali metal residue into a quantifiable concentration range by correlating the sodium ion concentration in the dealkali-treated solid phase leachate with preset concentration thresholds. The preset first concentration serves as the boundary line for residues meeting requirements, and the preset second concentration serves as the distinguishing line for the causes of abnormal residues. The preset first and second concentrations can be set according to actual operating conditions. The setting of the preset first and second concentrations aims to ensure the dealkali treatment effect and practicality of aluminum-silicon solid waste. Optionally, the preset first and second concentrations are determined through a limited number of experiments by evaluating the dealkali treatment effect of different sodium ion concentrations on aluminum-silicon solid waste. The determined preset first and second concentrations should be neither too low nor too high, and should not cause excessive interference to the dealkali treatment process of aluminum-silicon solid waste. For example, the preset first concentration is generally selected in the range of [350 mg / L, 450 mg / L], and the preset second concentration is generally selected in the range of [500 mg / L, 600 mg / L].

[0048] Preferably, the first preset concentration is 400 mg / L, and the second preset concentration is 550 mg / L.

[0049] Specifically, the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase is the sodium ion content released into the liquid phase by the leaching method under a preset solid-liquid ratio.

[0050] Specifically, the leaching method is essentially a standardized dissolution test method used to characterize the release capacity of target ions from the solid phase to the liquid phase under uniform and controlled liquid-solid contact conditions. Generally, in order to avoid deviations in measurement results caused by local saturation or excessive dilution of the liquid phase, and to ensure that the dissolution process has sufficient mass transfer driving force, a preset solid-liquid ratio of 1:10 is commonly selected.

[0051] Specifically, the construction of the structural disturbance mechanism and the increase of the alternating pressure difference amplitude include: The pressure differential mechanism construction module is used to apply different pressures to opposite ends of the reaction space of the reaction unit to form a pressure difference and construct a basic pressure differential field. The pressure variation mechanism construction module is used to superimpose periodic pressure disturbances on the basic pressure difference field to form an alternating pressure difference field; The voltage switching mechanism module is used to suppress the desorption and resorption of alkali metal ions by increasing the amplitude of the alternating voltage difference.

[0052] Specifically, the process of applying different pressures to the opposite ends of the reaction space of the reaction unit to form a pressure difference and construct a basic pressure difference field is to apply different pressures to the opposite ends of the reaction space of the reaction unit, so that the liquid phase or gas phase generates a stable pressure gradient along the interior, thereby establishing a basic pressure difference field to drive the migration of alkali metal ions.

[0053] Specifically, the process of superimposing periodic pressure disturbances on the base pressure differential field to form an alternating pressure differential field is as follows: on the base pressure differential field, the pressure on one side of the reaction space is periodically adjusted according to a preset periodic change law, so that the pressure changes with time between the maximum and minimum values ​​periodically, thereby superimposing an alternating pressure differential field on the base pressure differential field.

[0054] Specifically, the pressure change waveform corresponding to the preset periodic change pattern includes sine wave, square wave, and pulse wave, with the preferred embodiment being a sine wave.

[0055] Specifically, the frequency of periodic pressure disturbance is generally selected in the range of [0.6Hz, 1Hz].

[0056] Specifically, the increase in the amplitude of the alternating pressure difference is determined by the difference between the concentration of alkali metal ions in the leachate of the dealkalized solid phase and the preset first concentration.

[0057] Specifically, when the difference between the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase and the preset first concentration is within 20 mg / L, the alternating pressure difference amplitude increases to 1.1 times the original value. When the difference between the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase and the preset first concentration exceeds 20 mg / L, in addition to increasing to 1.1 times the original value, the alternating pressure difference amplitude increases by 0.5 kPa for every 5 mg / L exceeding the original value. For example, when the difference between the concentration of alkali metal ions in the leachate of the dealkali-treated solid phase and the preset first concentration is 30 mg / L, and the current alternating pressure difference amplitude is 10 kPa, the increased alternating pressure difference amplitude is 10 × 1.1 + 0.5 × 2 = 12 kPa.

[0058] In practice, the system of the present invention determines whether to construct a structural disturbance mechanism and adjusts the amplitude of alternating pressure difference by setting a preset first concentration and a preset second concentration. Since the pore structure and surface active sites of solid particles may lead to the re-adsorption or local concentration retention of alkali metal ions during the dealkali removal process, static leaching is difficult to completely remove residual alkali metals. By constructing a structural disturbance mechanism and increasing the amplitude of alternating pressure difference, the material exchange efficiency of the solid-liquid interface can be enhanced, the migration and release of residual alkali metal ions on the surface and in the pores of solid particles can be promoted, the residual amount of alkali metal can be reduced, and the completeness of dealkali removal of aluminum-silicon solid waste can be further improved.

[0059] Please continue reading. Figure 4 As shown, it is a logic flowchart of the process of determining whether to add a low-concentration weak acid solution in the aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to an embodiment of the present invention.

[0060] Specifically, the dealkali-removing environment adjustment module, in response to a condition where the concentration of alkali metal ions in the leachate of the dealkali-removing solid phase is greater than the preset second concentration, determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali-removing process.

[0061] Specifically, the dealkali removal environment adjustment module determines that the release stability of the bound alkali meets the requirements when the net release rate of alkali metal ions during the dealkali removal process is greater than the preset release rate. The dealkali removal environment adjustment module responds to the fact that the net release rate of alkali metal ions during the dealkali removal process is less than or equal to the preset release rate, determines that the release stability of the bound alkali does not meet the requirements, and adds a low-concentration weak acid solution.

[0062] It is understandable that the two intervals defined by the preset release rate correspond to two different scenarios: The first interval is when the net release rate of alkali metal ions is less than or equal to the preset release rate. The corresponding situation is that alkali metal ions in the active sites and pores of the solid phase are easily re-adsorbed under changes in concentration gradient or temperature fluctuation, causing the net release rate to fluctuate. The second interval is when the net release rate of alkali metal ions during the dealkali removal process is greater than the preset release rate. The corresponding situation is that the release stability of the bound alkali is determined to meet the requirements.

[0063] Understandably, in the lattice distortion-based dealkali removal and resource utilization system for aluminum-silicon solid waste, the net release rate of alkali metal ions during the dealkali removal process characterizes the release stability of the bound alkali. The core logic is to compare the net release rate with the preset release rate, and determine whether the bound alkali can be released stably by checking whether the actual rate is greater than the preset threshold. The preset release rate serves as the dividing line for determining whether the stability meets the requirements. The preset release rate can be set according to the actual working conditions. The setting of the preset release rate aims to ensure the dealkali removal effect and practicality of aluminum-silicon solid waste. Optionally, the preset release rate is determined through a limited number of experiments by evaluating the dealkali removal effect of different ions on aluminum-silicon solid waste. The determined preset release rate should be neither too small nor cause excessive interference to the dealkali removal reaction process of aluminum-silicon solid waste. For example, the preset release rate is generally selected in the range of [4 mg / (L·min), 6 mg / (L·min)].

[0064] Preferably, the preferred embodiment of the preset release rate is 5 mg / (L·min).

[0065] Specifically, mg / (L·min) is the unit of the net release rate of alkali metal ions during the dealkali removal process. It means milligrams per liter per minute, that is, the content of alkali metal ions present in the liquid phase per minute per liter.

[0066] Specifically, the net release rate of alkali metal ions during the dealkali removal process is the difference between the number of alkali metal ions released from the dealkali removal solid phase to the liquid phase per unit time and the amount of re-adsorption.

[0067] Specifically, the concentration of the low-concentration weak acid solution is determined by the difference between the preset release rate and the net release rate of alkali metal ions during the dealkalization process.

[0068] Specifically, when the difference between the preset release rate and the net release rate of alkali metal ions during the dealkali removal process is within 1 mg / (L·min), a 0.01 mol / L weak acid solution is added. When the difference exceeds 1 mg / (L·min), in addition to adding 0.01 mol / L weak acid solution, the concentration of the weak acid solution is increased by 0.01 mol / L for every 1 mg / (L·min) exceeding the preset release rate. For example, when the difference between the preset release rate and the net release rate of alkali metal ions during the dealkali removal process is 2 mg / (L·min), the concentration of the weak acid solution to be added is 0.01 + 0.01 × 1 = 0.02 mol / L.

[0069] Specifically, the amount of the low-concentration weak acid solution added is generally selected in the range of 4% to 6% of the total liquid volume in the permeable system. Preferably, the preferred embodiment of the amount of the low-concentration weak acid solution added is 5% of the total liquid volume in the permeable system.

[0070] In practice, the system of the present invention determines the addition of a low-concentration weak acid solution by setting a preset release rate. Since alkali metal ions in the active sites and pores of the solid phase are easily re-adsorbed under changes in concentration gradient or temperature fluctuations, the net release rate fluctuates. By adding a low-concentration weak acid solution, a weak dissolution layer can be formed to increase the local solubility of iron and aluminum ions to occupy the active sites on the surface, effectively suppressing the re-adsorption of alkali metal ions, ensuring the stability of the continuous release of bound alkali, and further improving the completeness of alkali removal from aluminum-silicon solid waste.

[0071] In a specific embodiment, the dealkalization and resource recovery of red mud based on lattice distortion includes the following steps: Mix 100g of red mud with water at a solid-liquid ratio of 1:10 to form a slurry, resulting in 1100g of a permeable system; CO2 gas was introduced into the pulping system and pressurized under a controlled pressure of 0.2 MPa for 2 hours. At the same time, a base pressure difference of 0.1 MPa was applied across the reaction space and a periodic sinusoidal pressure disturbance was superimposed. During the dealkali removal process, the net release rate of alkali metal ions was detected to be 1 mg / (L·min). An acetic acid solution with a concentration of 0.05 mol / L was added to the permeable system. After the reaction, a de-alkali solid phase and an alkali-containing liquid phase were obtained by liquid-solid separation. The residual alkali content of the de-alkali solid phase was calculated to be approximately 1.5%, and the de-alkali removal rate was 88%. The Na content in the alkali-containing liquid phase was... + The concentration was 7.8 g / L; The dealkalized solid phase is further used for magnetic separation of iron-rich materials and acid leaching of aluminum, and the liquid phase can be recycled to prepare alkali metal salts; Specifically, the alkali content of the original solid waste of the red mud is 12g equivalent of Na2O.

[0072] Specifically, the periodic sinusoidal pressure disturbance has an amplitude of ±0.02 MPa and a frequency of 0.8 Hz.

[0073] Specifically, the amount of acetic acid solution added is 22g of a 0.05mol / L aqueous acetic acid solution.

[0074] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A system for dealkali removal and resource utilization of aluminum-silicon solid waste based on lattice distortion, characterized in that, include: The dealkali control module includes a pulping unit for converting aluminum-silicon solid waste into a permeable system, a pressurized permeation unit connected to the pulping unit for introducing acidic gas into the permeable system under controlled pressure, and a reaction unit connected to the pressurized permeation unit for causing lattice distortion in the aluminum-silicon solid waste through the acidic gas in a closed environment to complete the dealkali removal. The resource recovery module is connected to the dealkali control module, and includes a separation unit for separating the dealkali solid phase and the alkali-containing liquid phase after dealkali removal, and a recovery unit connected to the separation unit for recycling the dealkali solid phase and the alkali-containing liquid phase to obtain metal resources and alkali metal salts respectively. The dealkali determination module, which is connected to the resource recycling module, is used to determine whether the dealkali removal of aluminum-silicon solid waste meets the requirements based on the dealkali removal completion rate. The pressure change mechanism construction module is connected to the dealkali control module and the dealkali determination module respectively, and is used to determine whether to construct a structural disturbance mechanism and determine the amplitude of the alternating pressure difference based on the concentration of alkali metal ions in the leachate of the dealkali solid phase. The dealkali removal environment adjustment module is connected to the dealkali removal control module and the pressure swing mechanism construction module, respectively, and is used to determine whether to add a low-concentration weak acid solution based on the net release rate of alkali metal ions during the dealkali removal process.

2. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 1, characterized in that, The dealkali determination module determines that the dealkali removal completion rate meets the requirements when the dealkali removal completion rate is greater than the preset completion rate. The dealkali determination module determines that the completeness of dealkali removal of aluminum-silicon solid waste does not meet the requirements when the dealkali removal completion rate is less than or equal to the preset completion rate.

3. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 2, characterized in that, The pressure-changing mechanism construction module, in response to the condition that the completeness of dealkali removal from the aluminum-silicon solid waste does not meet the requirements, determines whether the residual amount of alkali metal in the dealkali solid phase meets the requirements based on the concentration of alkali metal ions in the leachate of the dealkali solid phase.

4. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 3, characterized in that, The pressure swing mechanism construction module determines that the residual alkali metal in the dealkali solid phase meets the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is less than or equal to a preset first concentration. The pressure swing mechanism construction module determines that the residual alkali metal in the dealkali solid phase does not meet the requirements when the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset first concentration.

5. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 4, characterized in that, The pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkalized solid phase is greater than the preset first concentration and less than or equal to the preset second concentration, and constructs a structural disturbance mechanism and increases the amplitude of the alternating pressure difference. The pressure swing mechanism construction module responds to the fact that the concentration of alkali metal ions in the leachate of the dealkali solid phase is greater than the preset second concentration, initially determines that the release stability of the bound alkali does not meet the requirements, and determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali process.

6. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 5, characterized in that, The construction of the structural disturbance mechanism and the increase of the alternating pressure difference amplitude include: The pressure differential mechanism construction module is used to apply different pressures to opposite ends of the reaction space of the reaction unit to form a pressure difference and construct a basic pressure differential field. The pressure variation mechanism construction module is used to superimpose periodic pressure disturbances on the basic pressure difference field to form an alternating pressure difference field; The voltage switching mechanism module is used to suppress the desorption and resorption of alkali metal ions by increasing the amplitude of the alternating voltage difference.

7. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 6, characterized in that, The increase in the amplitude of the alternating pressure difference is determined by the difference between the concentration of alkali metal ions in the leachate of the dealkalized solid phase and the preset first concentration.

8. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 7, characterized in that, The dealkali removal environment control module, in response to a condition where the concentration of alkali metal ions in the leachate of the dealkali removal solid phase is greater than the preset second concentration, determines whether the release stability of the bound alkali meets the requirements based on the net release rate of alkali metal ions during the dealkali removal process.

9. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 8, characterized in that, The dealkali removal environment regulation module determines that the release stability of the bound alkali meets the requirements when the net release rate of alkali metal ions during the dealkali removal process is greater than the preset release rate. The dealkali removal environment adjustment module responds to the fact that the net release rate of alkali metal ions during the dealkali removal process is less than or equal to the preset release rate, determines that the release stability of the bound alkali does not meet the requirements, and adds a low-concentration weak acid solution.

10. The aluminum-silicon solid waste dealkali removal and resource utilization system based on lattice distortion according to claim 9, characterized in that, The concentration of the low-concentration weak acid solution is determined by the difference between the preset release rate and the net release rate of alkali metal ions during the dealkalization process.

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