Method for regeneration of water glass spent sand based on mechanical regeneration and microwave enhanced cleaning

Abstract

This invention provides a method for regenerating water glass sand based on mechanical regeneration and microwave-enhanced cleaning. This invention relates to the field of material regeneration technology and includes the following steps: S1, high-speed stirring and friction destroy the binder film structure on the surface of the sand particles to obtain primary regenerated sand; S2, the primary regenerated sand is mixed with water in a certain proportion and sequentially fed into a primary microwave sand washing unit and a secondary microwave sand washing unit. The sand-water mixture is cleaned under the combined action of a microwave field and mechanical stirring; S3, the sand-water mixture after the primary microwave sand washing is pumped into a natural water control tank. The separated high-concentration wastewater is introduced into a primary filtration system, and the filtrate is returned to the primary circulating water tank for reuse in the primary sand washing. When the water quality does not meet the requirements, the wastewater is discharged to a deep treatment device. The regenerated sand obtained by this invention has a defilming rate ≥95%, Na2O residue ≤0.3%, and loss on ignition ≤0.3%, and its process performance fully meets the requirements for use as surface sand.

Description

Technical Field

[0001] This invention relates to the field of material recycling technology, and in particular to a method for recycling water glass waste sand based on mechanical recycling and microwave-enhanced cleaning. Background Technology

[0002] Water glass sand is widely used in cast steel, cast iron, and non-ferrous alloy casting due to its environmental friendliness and high casting precision. However, the sodium silicate binder film remaining on the surface of the used sand particles after casting has high strength and poor collapsibility, leading to a sharp decline in the direct reuse performance of the used sand. To achieve the recycling of used water glass sand, this binder film must be effectively removed through regeneration technology.

[0003] Currently, the mainstream regeneration technologies are divided into dry regeneration and wet regeneration. Dry regeneration (such as CN118385443A) removes the adhesive film through mechanical friction and collision between sand particles. It has the advantages of simple system and no wastewater generation, but it has problems such as low film removal rate (usually less than 40%), severe sand particle breakage, and low quality of regenerated sand. It can mostly only be used as backing sand.

[0004] Wet recycling (such as CN104759584A and CN117483640A) utilizes the water solubility of sodium silicate to dissolve and peel off the adhesive membrane through hydraulic scrubbing, achieving a high membrane removal rate (up to 80%–95%) and producing high-quality recycled sand that can replace new sand. However, traditional wet recycling suffers from inherent problems such as huge water consumption (the sand-to-water ratio is often as high as 1:2 or more), the generation of large amounts of alkaline wastewater and sludge, and high energy consumption for drying wet sand, resulting in high operating costs and significant environmental impact.

[0005] To overcome the limitations of single technologies, composite regeneration processes have emerged. For example, CN111468673A discloses a process of calcination + hot grinding + ultrasonic treatment. While this improves the demolding rate, the calcination process has extremely high energy consumption, a complex system, and difficult-to-control operating costs. Another example is CN104399877B, which discloses a method for efficiently regenerating used water glass sand using microwaves. This method involves soaking the used sand in a strongly alkaline sodium hydroxide solution and heating it to 100-200°C in a microwave reactor. Although this method achieves a high demolding rate, it is essentially a chemical-thermal regeneration process. It introduces a high concentration of strong alkali as the reaction medium, which not only increases the safety risks and management costs associated with the procurement, storage, and use of chemicals, but more importantly, it generates a large amount of high-concentration, strongly alkaline waste solution. Although the patent mentions that the alkali solution can be recycled, in actual industrial production, the loss, pollution accumulation, and treatment of the alkali solution are extremely challenging. The difficulty and cost of its subsequent treatment even exceed those of traditional wet regeneration, posing a serious risk of secondary pollution. This method did not solve the inherent problems of high pollution and high cost in wet regeneration; instead, it introduced new sources of chemical pollution.

[0006] Therefore, there is an urgent need in this field for a green, economical, and efficient new method and system for regenerating water glass sand that can significantly reduce water consumption, energy consumption, and wastewater discharge while ensuring high demolding rate and quality of regenerated sand. Summary of the Invention

[0007] To address the aforementioned issues, this invention provides a method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning. The regenerated sand obtained by this invention has a decoction rate of ≥95%, a Na2O residue of ≤0.3%, and a loss on ignition of ≤0.3%, and its process performance fully meets the requirements for use as face sand.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] The water glass sand regeneration method based on mechanical regeneration and microwave-enhanced cleaning includes the following steps: S1, high-speed stirring and friction destroy the binder film structure on the surface of sand particles to obtain primary regenerated sand; S2, the primary regenerated sand and water are mixed in proportion and sequentially fed into the primary microwave sand washing unit and the secondary microwave sand washing unit, where the sand-water mixture is washed under the combined action of microwave field and mechanical stirring; S3, the sand-water mixture after primary microwave sand washing is fed into a natural water control tank, and the separated high-concentration wastewater is introduced into the primary filtration system. The filtrate is returned to the primary circulating water tank for reuse in primary sand washing. When the water quality does not meet the requirements, the wastewater is discharged to the deep treatment device; S4, the wet sand enters the secondary sand washing process. After solid-liquid separation in the natural water control tank, the low-concentration wastewater is filtered through a filter membrane and fed into the secondary circulating water tank. Part of the wastewater is added to the primary circulating water tank, and part is reused in secondary sand washing.

[0010] Preferably, the wet sand obtained after secondary sand washing is dehydrated and then sent to a drying equipment for drying; the dried sand particles are screened and cooled to finally obtain high-quality recycled sand.

[0011] Preferably, the mechanical regeneration in step S1 is carried out in a vertical friction regeneration machine. First, the old water glass sand is crushed and magnetically separated, and then the crushed and magnetically separated old sand is sent into the vertical friction regeneration machine.

[0012] Preferably, in step S1, the rotation speed is 900~1500 r / min, the processing time is 5~15 min, and the temperature is 50~80℃.

[0013] Preferably, the microwave washing unit has a microwave frequency of 2450 MHz, a power of 10~30 kW, a single-stage processing time of 1~3 min, and a sand to water mass ratio of 1:1~1:2.

[0014] Preferably, in step S3, fly ash is added as a filter aid during the filtration process.

[0015] Preferably, the amount of fly ash added is 1‰ to 3‰ of the wastewater mass; the industrial filter membrane is a microfiltration membrane or an ultrafiltration membrane with a pore size range of 0.01μm to 10μm.

[0016] Preferably, when the water quality parameters of the circulating water exceed the preset threshold, a portion of the wastewater is discharged and replenished. The preset water quality threshold for discharge is turbidity ≥ 1200 NTU or pH ≥ 10.

[0017] The beneficial effects of this invention are as follows:

[0018] Compared with existing technologies, the recycled sand obtained by this invention has excellent quality and can replace virgin sand as a surface sand: through the synergistic effect of mechanical film breaking and microwave physical enhanced cleaning, the binder film is thoroughly removed. Mechanical pretreatment creates favorable interface conditions for microwave cleaning, while microwave cleaning utilizes the bulk heating effect to efficiently peel off the weakened film layer from the inside. The recycled sand has a film removal rate of ≥95%, Na2O residue of ≤0.3%, and loss on ignition of ≤0.3%, and its process performance fully meets the requirements for surface sand use. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] See attached document Figure 1 This invention relates to the field of foundry waste sand regeneration technology, specifically disclosing a low-consumption and environmentally friendly regeneration method and system for water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning.

[0022] This method, through a synergistic process of mechanical regeneration pretreatment, two-stage microwave-enhanced cleaning, fractional filtration, and wastewater recycling, achieves near-zero water discharge and a significant reduction in energy consumption while efficiently removing surface adhesives from sand particles.

[0023] Specifically, the process includes: firstly, mechanical friction pretreatment of the old sand to disrupt the integrity of the binder film; then, in a two-stage vertical microwave sand washing machine, the heating effect of microwaves is used to enhance the removal of residual binder by water; the core innovation lies in the separate treatment of the two-stage sand washing wastewater. The primary wastewater is reused after being significantly reduced in turbidity using fly ash as a filter aid, while the secondary wastewater is recycled after deep purification through membrane filtration, with only a small amount discharged when the system water quality reaches a preset threshold.

[0024] This invention achieves green, economical, and efficient regeneration of water glass waste sand by combining process synergy and differentiated water treatment, while ensuring the quality of regenerated sand (Na2O residue ≤0.3%, descaling rate ≥95%). The water consumption per unit product is only 10% to 20% of that of traditional wet processes.

[0025] The purpose of this invention is to overcome the shortcomings of existing technologies, particularly addressing the core challenges of high water consumption, heavy wastewater pollution, and high treatment costs in existing wet regeneration and microwave-chemical regeneration technologies. This invention provides a low-consumption and environmentally friendly regeneration method and system for water glass waste sand. Through the deep synergy of three core processes—mechanical membrane breaking pretreatment, two-stage microwave physical enhanced cleaning, and fractional filtration with near-zero wastewater discharge—this invention achieves efficient membrane removal from waste sand and obtains high-quality regenerated sand while reducing water consumption and wastewater discharge to extremely low levels compared to traditional processes, thus achieving a balance between economic and environmental benefits. To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0026] In a first aspect, the present invention provides a method for regenerating waste water glass sand, comprising the following steps:

[0027] S1. Pretreatment and Mechanical Regeneration: The old water glass sand is crushed and magnetically separated to remove metal impurities and large sand blocks; then the crushed old sand is subjected to mechanical regeneration pretreatment, in which the binder film structure on the surface of the sand particles is destroyed by high-speed stirring and friction to obtain primary regenerated sand.

[0028] This step achieves mechanical regeneration pretreatment by mechanically rubbing the old water glass sand to break the binder film on the surface of the sand particles.

[0029] S2. Two-stage microwave-enhanced sand washing: The primary recycled sand is mixed with water in a certain proportion and then fed into the first-stage microwave sand washing unit and the second-stage microwave sand washing unit in sequence. The process is carried out in the first-stage microwave sand washing unit and the second-stage microwave sand washing unit in sequence. In each unit, the sand-water mixture is cleaned under the combined action of microwave field and mechanical stirring. The bulk heating effect of microwave is used to accelerate the dissolution and peeling of the adhesive film.

[0030] This step achieves two-stage microwave sand washing, where the pre-treated old sand is mixed with water and then processed sequentially through a primary microwave sand washing unit and a secondary microwave sand washing unit, using microwave energy to enhance the cleaning of residual adhesive film.

[0031] S3. Separate Filtration and Wastewater Recycling: The sand-water mixture after the first-stage microwave sand washing is fed into a natural water control chamber. The separated high-concentration wastewater is introduced into the first-stage filtration system, and fly ash is added as a filter aid during the filtration process. The filtrate is returned to the first-stage circulating water tank and reused in the first-stage sand washing. Only when the water quality does not meet the requirements is the wastewater discharged to the deep treatment device. The wet sand enters the second-stage sand washing process via a screw feeder. After the sand-water mixture after the second-stage microwave sand washing undergoes solid-liquid separation in the natural water control chamber, the low-concentration wastewater is filtered through a filter membrane and fed into the second-stage circulating water tank. Part of it is used to supplement the first-stage circulating water tank, and part is reused in the second-stage sand washing. By filtering the sand washing wastewater from both stages and keeping it for later use, it is possible to replenish the cleaning water for the first-stage microwave sand washing unit and ensure the cleanliness of the second-stage microwave sand washing unit, reducing impurity residue and improving the final demolding rate.

[0032] This step achieves separation filtration and wastewater recycling. The high-concentration wastewater discharged from the primary microwave sand washing unit is subjected to primary filtration, with fly ash added as a filter aid during the filtration process. The filtrate is returned to the primary microwave sand washing unit for recycling. The low-concentration wastewater discharged from the secondary microwave sand washing unit is subjected to secondary filtration, using an industrial filter membrane for precision filtration. Part of the filtrate is added to the primary recycling system, and the other part is returned to the secondary microwave sand washing unit for recycling. The filter residue is dewatered and disposed of as solid waste.

[0033] S4. Dehydration and drying: The wet sand obtained after secondary sand washing is dehydrated and then sent to drying equipment for drying.

[0034] S5. Post-processing: The dried sand particles are screened and cooled to obtain high-quality recycled sand.

[0035] Specifically, in step S1, the mechanical regeneration is carried out in a vertical friction regeneration machine. First, the old water glass sand is crushed and magnetically separated. Then, the crushed and magnetically separated old sand is fed into the vertical friction regeneration machine. The rotation speed is 900~1500 r / min, and the processing time is 5~15 min. Slight heating may be carried out during the processing. At this time, the slight heating is the heat generated by friction, and the temperature is 50~80℃.

[0036] Specifically, in step S2, the microwave frequency of the microwave sand washing unit is 2450 MHz, the power is 10~30 kW, the single-stage processing time is 1~3 min, and the mass ratio of sand to water is 1:1~1:2.

[0037] Specifically, in step S3, the amount of fly ash added is 1‰ to 3‰ of the wastewater mass; the industrial filter membrane is a microfiltration membrane or an ultrafiltration membrane with a pore size range of 0.01μm to 10μm.

[0038] Specifically, in step S3, wastewater is recycled. When the water quality parameters of the recycled water exceed a preset threshold, a portion of the wastewater is discharged and replenished. Wastewater is recycled at least five times before it needs to be discharged. The preset water quality threshold for discharge is preferably turbidity ≥ 1200 NTU or pH ≥ 10.

[0039] Specifically, in step S4, the dehydration treatment includes natural water control and mechanical dehydration to reduce the moisture content of the wet sand to below 5%; the drying adopts a three-pass dryer with a drying temperature of 200~400℃ and a drying time of 20~40 minutes.

[0040] Secondly, the present invention provides a regeneration system for implementing the above-described method, comprising:

[0041] The pretreatment and mechanical regeneration unit includes a crusher, a magnetic separator, and a vertical friction regenerator connected in sequence; it is used to crush, magnetically separate, and frictionally pretreat old sand.

[0042] A two-stage microwave sand washing unit includes a first-stage vertical microwave sand washing machine and a second-stage vertical microwave sand washing machine connected in series. The microwave sand washing machine includes a housing, a stirring device disposed within the housing, and a microwave generator installed on the outer wall or inside the housing.

[0043] The separate filtration and wastewater recycling unit specifically includes: a primary filtration subsystem (sedimentation tank and fly ash dosing device) connected to the drain outlet of the primary sand washing machine; a secondary filtration subsystem (industrial membrane filter) connected to the drain outlet of the secondary sand washing machine; and a primary and secondary circulating water tanks for storing filtered clean water, which are connected to the corresponding sand washing machines via water pumps to form a closed-loop circulation.

[0044] The dehydration and drying unit includes a dehydration device (such as a centrifugal dehydrator) and a dryer (such as a three-pass dryer) connected in sequence.

[0045] The post-processing unit includes a vibrating screen and a sand cooler connected in sequence.

[0046] The control system is used to monitor the water quality parameters of the primary circulating water online and automatically control the operation of wastewater discharge, secondary water replenishment to the primary system, and fresh water replenishment to the secondary system according to preset thresholds.

[0047] The beneficial effects of this invention are as follows:

[0048] 1. Recycled sand is of excellent quality and can replace virgin sand as a surface cleaning agent: Through the synergistic effect of mechanical film breaking and microwave physical enhanced cleaning, the binder film is thoroughly removed. Mechanical pretreatment creates favorable interface conditions for microwave cleaning, while microwave cleaning utilizes the bulk heating effect to efficiently peel off the weakened film layer from the inside. The recycled sand has a film removal rate ≥95%, Na2O residue ≤0.3%, and loss on ignition ≤0.3%, and its process performance fully meets the requirements for surface cleaning.

[0049] 2. Extremely low water consumption and wastewater discharge, environmentally friendly: This invention innovatively introduces a fractional filtration and wastewater recycling system. Primary wastewater utilizes fly ash as a filter aid—a clever waste-to-waste approach—significantly reducing treatment load and costs; secondary wastewater undergoes low-cost deep purification through membrane filtration. This fractional strategy allows over 95% of the process water to be recycled within the system for more than 5 cycles, and the fresh water replenishment per unit of regenerated sand is only 10%~20% of that in traditional wet processes, truly achieving near-zero wastewater discharge and fundamentally solving the environmental challenges of wet regeneration.

[0050] 3. Significant energy saving and consumption reduction, low operating costs: Microwave heating is a volumetric heating method with high energy utilization and low heat loss. Furthermore, the microwaves in this invention are primarily used for physical strengthening rather than macroscopic heating to high temperatures, thus the energy consumption is far lower than that of roasting or high-temperature alkaline boiling methods. Simultaneously, the significant reduction in wastewater treatment volume and difficulty also results in considerable energy and reagent cost savings. Comprehensive calculations show that the direct regeneration cost of this invention is only 30% to 40% of the cost of purchasing new sand.

[0051] 4. High system integration and high degree of automation: The entire regeneration system has a clear process and compact equipment. The control system realizes the automated operation of online water quality monitoring, wastewater treatment and water replenishment. It is easy to operate and easy to promote and apply in industrial applications.

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention.

[0053] Example 1

[0054] This embodiment 1 provides a low-consumption and environmentally friendly recycling method and system for water glass waste sand, the object of which is water glass waste sand produced by a lining plant.

[0055] S1. Pretreatment and Mechanical Regeneration: The collected old sand blocks are first crushed by a jaw crusher, and then ferrous impurities are removed by a magnetic separator. The crushed and magnetically separated old sand is then fed into a vertical friction regeneration machine, where it is stirred and frictionally subjected to a speed of 1000 r / min for 10 minutes. During this process, hot water is circulated through the equipment jacket to maintain the material temperature at around 60℃. This step can remove approximately 15%~20% of the binder film.

[0056] S2. Two-stage microwave-enhanced sand washing: Mechanically regenerated sand particles are fed into a first-stage vertical microwave sand washing machine via a screw feeder, controlling the sand-to-water mass ratio at 1:1. The agitator (200 r / min) and microwave generator (20 kW) are started and processed for 2 minutes. Then, the sand-water mixture after the first-stage washing is pumped into a natural water control chamber for solid-liquid separation. The wet sand enters the second-stage vertical microwave sand washing machine for secondary washing and solid-liquid separation under the same conditions.

[0057] S3. Multi-stage Filtration and Wastewater Recirculation: Wastewater (turbidity approximately 800 NTU) discharged from the primary natural water control tank flows into the sedimentation tank. Fly ash (1‰ of the wastewater mass) is added at the overflow outlet for filtration. The filtrate (turbidity reduced to approximately 500 NTU) enters the primary circulating water tank. Wastewater (turbidity approximately 300 NTU) discharged from the secondary natural water control tank directly enters a membrane filter (0.1 μm pore size) for precision filtration, resulting in effluent turbidity below 50 NTU. The filtrate enters the secondary circulating water tank. Water is then pumped to both stages of the microwave sand washing machine as makeup water. This system operates continuously until the pH value of the wastewater discharged from the primary natural water control tank is >10 or the turbidity is >1500 NTU. At this point, the wastewater is discharged to the plant's wastewater treatment facility, and water from the secondary circulating water tank is introduced into the primary circulating water tank, while the secondary circulating water tank is replenished with tap water.

[0058] S4. Dehydration and Drying: The wet sand obtained after secondary sand washing is controlled for water in a natural water control chamber for 6 hours, and then dehydrated by a centrifugal dehydrator to reduce the moisture content to about 5%. Then it is sent to a three-pass rotary dryer and dried at 280℃ for 25 minutes.

[0059] S5. Post-processing: The dried hot sand is screened by a linear vibrating screen to remove fine particles, and then cooled to room temperature (≤30℃) by a sand temperature cooler to obtain the final recycled sand product with a Na2O residue of 0.21% and a demolding rate of 96.5%.

[0060] Example 2

[0061] Embodiment 2 of the present invention provides a low-consumption and environmentally friendly recycling method and system for used water glass sand. The difference between this embodiment and Embodiment 1 is that the sand-to-water ratio is 1:2. The residual Na2O content in the recycled sand is 0.16%, and the demolding rate is 98.3%.

[0062] Example 3

[0063] Embodiment 3 of the present invention provides a low-consumption and environmentally friendly recycling method and system for used water glass sand. The difference between this embodiment and Embodiment 1 is that the microwave power is 30kW. The residual Na2O content in the recycled sand is 0.18%, and the demolding rate is 97.8%.

[0064] Comparative Example 1

[0065] Comparative Example 1 of this invention provides a low-consumption and environmentally friendly recycling method and system for used water glass sand. The difference between this comparative example and Example 1 is that the microwave power is 0 kW. The residual Na2O content in the recycled sand is 0.63%, and the demolding rate is 78.1%.

[0066] Comparative Example 2

[0067] Comparative Example 2 of this invention provides a low-consumption and environmentally friendly recycling method and system for used water glass sand. The difference between this comparative example and Example 1 is that the fly ash addition is 0. The residual Na2O content in the recycled sand is 0.45%, and the demolding rate is 81.7%.

[0068] Comparative Example 3

[0069] Comparative Example 3 of this invention provides a low-consumption and environmentally friendly method and system for the recycling of waste water glass sand. The difference between this comparative example and Example 1 is that the wastewater from the two-stage sand washing process is filtered and then mixed for later use. The residual Na2O content in the recycled sand is 0.38%, and the demolding rate is 84.5%.

[0070] The above embodiments and comparative examples fully demonstrate that the method and system provided by the present invention are superior to existing traditional recycling technologies in multiple dimensions such as water consumption, energy consumption, environmental protection and recycled sand quality, and have significant industrial application value and market prospects.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning, characterized in that, Includes the following steps: S1. High-speed stirring and friction destroy the binder film structure on the surface of sand particles to obtain primary recycled sand; S2. The primary recycled sand and water are mixed in proportion and then fed into the first-stage microwave sand washing unit and the second-stage microwave sand washing unit in sequence. The sand-water mixture is cleaned under the combined action of microwave field and mechanical stirring. S3. The sand-water mixture after primary microwave sand washing is fed into the natural water control tank. The high-concentration wastewater separated is introduced into the primary filtration system. The filtrate is returned to the primary circulating water tank for reuse in primary sand washing. When the water quality does not meet the requirements, the wastewater is discharged to the deep treatment device. S4. The wet sand enters the secondary sand washing process. After the sand-water mixture after the secondary microwave sand washing is separated into solid and liquid by the natural water control chamber, the low-concentration wastewater is filtered through the filter membrane and then pumped into the secondary circulating water tank. Part of it is added to the primary circulating water tank and part of it is reused in the secondary sand washing.

2. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 1, characterized in that, The wet sand obtained after secondary sand washing is dehydrated and then sent to a drying equipment for drying. The dried sand particles are then screened and cooled to finally obtain high-quality recycled sand.

3. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 1, characterized in that, In step S1, mechanical regeneration is carried out in a vertical friction regeneration machine. First, the old water glass sand is crushed and magnetically separated, and then the crushed and magnetically separated old sand is sent into the vertical friction regeneration machine.

4. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 3, characterized in that, In step S1, the rotation speed is 900~1500 r / min, the processing time is 5~15 min, and the temperature is 50~80℃.

5. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 1, characterized in that, The microwave sand washing unit has a microwave frequency of 2450 MHz, a power of 10~30 kW, a single-stage processing time of 1~3 min, and a sand to water mass ratio of 1:1~1:

2.

6. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 1, characterized in that, In step S3, fly ash is added as a filter aid during the filtration process.

7. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 6, characterized in that, The amount of fly ash added is 1‰ to 3‰ of the wastewater mass; the industrial filter membrane is a microfiltration membrane or an ultrafiltration membrane with a pore size range of 0.01μm to 10μm.

8. The method for regenerating water glass waste sand based on mechanical regeneration and microwave-enhanced cleaning according to claim 1, characterized in that, When the water quality parameters of the circulating water exceed the preset threshold, part of the wastewater will be discharged and replenished. The preset water quality threshold for discharge is turbidity ≥ 1200 NTU or pH ≥ 10.

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