Method for sorting different components of crystalline silicon photovoltaic module by utilizing pulsating airflow

Abstract

The invention discloses a method for sorting different components of a crystalline silicon photovoltaic module by utilizing pulsating airflow, which is characterized in that a pulsating airflow sorting device is used, and separation and enrichment of different components in a mixed material of three components of waste crystalline silicon photovoltaic module glass particles, solar cells and solder strips are realized by adjusting airflow, pulsating frequency and feeding amount. And after pulsating airflow separation is carried out under proper operation conditions, the recovery rate and the grade of the glass particles, the solar cells and the welding strips are all greater than 95%. According to the technical scheme, efficient separation and enrichment of single components in the crystalline silicon photovoltaic module glass particles, solar cells and solder strip mixed materials are achieved, subsequent deep recovery is facilitated, the technological process is simple, efficiency is high, green, low-carbon and environment-friendly, secondary waste is avoided, and the operation and management cost is effectively reduced.

Description

Technical Field

[0001] The invention relates to a method for recycling different components of waste crystalline silicon photovoltaic modules, in particular to a method for classifying and enriching glass particles, solar cell sheets and welding strips in crystalline silicon photovoltaic modules by using pulsating airflow. Technical Background

[0002] Photovoltaic modules are used on a large scale as an efficient, safe, easy-to-deploy and economical way of solar power generation. Since the average service life of photovoltaic modules is 25-30 years, the first peak of photovoltaic module retirement is coming. It is predicted that by 2030, 8 million tons of scrapped photovoltaic modules will be generated, and by 2050, this value will increase tenfold to 80 million tons. Among various types of photovoltaic modules, crystalline silicon photovoltaic modules account for more than 90% of the market share, so crystalline silicon photovoltaic modules are also the dominant type of discarded photovoltaic modules. Discarded crystalline silicon photovoltaic modules are a new type of valuable urban mineral. Recycling valuable materials from them can alleviate the material crisis and support the sustainable development of the photovoltaic industry.

[0003] At present, there are relatively few studies on the separation and enrichment of different components in crystalline silicon photovoltaic modules, and the research has not received enough attention. The proposed methods usually use simple screening, photoelectric sorting, electrostatic sorting, eddy current sorting processes, etc. Although these sorting methods can achieve partial separation of certain components, their separation and enrichment effects are not good, and the sorting efficiency and product quality are not ideal. Therefore, there is an urgent need for an effective separation and enrichment method that can achieve high sorting efficiency and product quality. In addition, this method uses air as the sorting medium, which is green and environmentally friendly and has no secondary pollution. Summary of the invention

[0004] Technical problem: The purpose of the present invention is to solve the problems in the prior art and to provide a method for classifying, separating and enriching different components of waste crystalline silicon photovoltaic modules, which has a simple process flow, is easy to operate, is green and environmentally friendly, and improves the recovery efficiency and grade of valuable components.

[0005] Technical solution: To achieve the above purpose, the present invention provides a method for sorting different components of crystalline silicon photovoltaic modules using pulsating airflow. First, the discarded crystalline silicon photovoltaic modules with the aluminum frame and junction box removed are pre-processed to obtain a mixture of glass particles, solar cells and solder strips; then, the mixture is crushed and sieved to obtain a target particle size; finally, the mixture is sorted using a pulsating airflow sorting device, and the classification and enrichment of different components in the mixture is finally achieved by adjusting parameters including airflow, pulsation frequency and feed amount. The specific steps are as follows:

[0006] a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules;

[0007] b. Pre-processing the discarded crystalline silicon photovoltaic modules with the junction box and aluminum frame removed to remove the encapsulant and backplane to obtain a mixture of glass particles, solar cells and solder strips;

[0008] c. The obtained mixed material is screened to obtain a mixed material of three components of glass particles, solar cells and welding strips with a particle size of 0.5-8 cm, and the mixed material with a particle size larger than the target particle size is crushed and screened again;

[0009] d. Feed the screened mixed material into the pulsating airflow sorting device from the feed port at a uniform speed, and adjust the airflow rate and pulsation frequency for airflow sorting;

[0010] e. Through two-stage sorting operations, the three materials of glass particles, solar cells and welding ribbons are classified, separated and enriched;

[0011] f. Collect light products at the discharge port at the upper end of the pulsating airflow sorting device, and collect heavy products at the discharge port at the lower end of the pulsating airflow sorting device. Through two-stage sorting, the classification and enrichment of single materials such as glass particles, solar cells and welding strips can be achieved.

[0012] In step b, the pretreatment includes anaerobic pyrolysis, aerobic roasting and chemical dissolution.

[0013] In step c, the crushing includes impact crushing or roller crushing.

[0014] In step c, the mixture of the three components of glass particles, solar cells and solder strips with a particle size of 0.5-8 cm obtained by screening, because the solder strip is in the form of a wire strip, its length will be greater than 8 cm, but must be less than 20 cm.

[0015] In step d, the pulsating airflow sorting device is an active pulsating airflow device, the airflow is introduced from the bottom of the device, and the sorting material is fed from the upper part of the device.

[0016] In step d, the mixed material is fed into the pulsating airflow sorting device from the feed port at a uniform speed, the feed speed is 50-300g / min, and the air flow rate is 50-140m 3 / h, the pulsation frequency is 0-10Hz.

[0017] In step e, the two-stage sorting operation:

[0018] In the first stage, pulsating airflow separation is used to separate glass particles, solar cells and welding ribbons. Most of the glass particles and solar cells are collected in the light product, and most of the welding ribbons are collected in the heavy product.

[0019] In the second stage, pulsating airflow separation is used to separate the glass particles and solar cells. Most of the solar cells are collected in the light products, and most of the glass particles are collected in the heavy products.

[0020] Beneficial effects: Due to the adoption of the above technical solution, the process of the present invention is simple, easy to operate, green and environmentally friendly, and improves the sorting efficiency and product quality in the process of separation and enrichment of different component materials in waste crystalline silicon photovoltaic modules. The recovery rate and quality of the sorted glass particles, solar cells and welding strips are greater than 95%. The main advantages compared with the existing technology are:

[0021] (1) Innovatively proposed the use of pulsating airflow sorting equipment to achieve high-efficiency, high-grade separation and enrichment of glass particles, solar cells and solder ribbons in waste crystalline silicon photovoltaic modules.

[0022] (2) By using air as the sorting medium, the entire sorting process does not require the investment of additional reagent costs and does not produce secondary pollutants, thus achieving low-carbon emission, green and environmentally friendly, low-cost separation and enrichment of valuable components in waste crystalline silicon photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the technical process of the present invention.

[0024] Figure 2 This is a schematic diagram of three products after sorting in the second implementation example of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the embodiments in the accompanying drawings:

[0026] like Figure 1 As shown, the method of using pulsating airflow to sort different components of crystalline silicon photovoltaic modules of the present invention, firstly, the waste crystalline silicon photovoltaic modules with the aluminum frame and the junction box removed are pre-processed to obtain a mixture of glass particles, solar cells and welding strips; then, the mixture of target particle size is obtained by crushing and screening; finally, the mixture is sorted by using a pulsating airflow sorting device, and the classification and enrichment of different components in the mixture is finally achieved by adjusting parameters including airflow, pulsation frequency and feed amount; the specific steps are as follows:

[0027] a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules;

[0028] b. Pre-treating the discarded crystalline silicon photovoltaic modules with the junction box and aluminum frame removed to remove the encapsulant and backplane to obtain a mixture of three components: glass particles, solar cells and solder strips; the pre-treatment includes anaerobic pyrolysis, aerobic roasting and chemical dissolution.

[0029] c. Screening the obtained mixed material to obtain a mixed material of three components, namely, glass particles, solar cells and solder strips with a particle size of 0.5-8 cm. The mixed material with a particle size larger than the target particle size is crushed and screened again; the crushing includes impact crushing the mixture with an impact crusher or roller crushing the mixture with a roller machine. In the mixed material of three components, namely, glass particles, solar cells and solder strips with a particle size of 0.5-8 cm, obtained by screening, the length of the solder strips may be greater than 8 cm, but must be less than 20 cm, because the solder strips are in the form of silk strips.

[0030] d. Feed the screened mixed material into the pulsating airflow sorting device at a uniform speed from the feed port, and adjust the airflow volume and pulsation frequency for airflow sorting; the pulsating airflow sorting device is an active pulsating airflow device, the airflow is introduced from the bottom of the device, and the sorted material is fed from the upper middle part of the device. The mixed material is fed into the pulsating airflow sorting device at a uniform speed from the feed port, the feeding speed is 50-300g / min, and the airflow volume is 50-140m 3 / h, the pulsation frequency is 0-10Hz.

[0031] e. The glass particles, solar cells and solder strips are separated and enriched by two-stage sorting operation; the two-stage sorting operation:

[0032] In the first stage, pulsating airflow is used to separate glass particles, solar cells and welding ribbons. Most of the glass particles and solar cells are collected in the light product, and most of the welding ribbons are collected in the heavy product.

[0033] In the second stage, pulsating airflow is used for sorting to separate glass particles and solar cells. Most of the solar cells are collected in the light products, and most of the glass particles are collected in the heavy products.

[0034] f. Collect light products at the discharge port at the upper end of the pulsating airflow sorting device, and collect heavy products at the discharge port at the lower end of the pulsating airflow sorting device, and achieve classification and enrichment of single materials of glass particles, solar cells and welding strips through two-stage sorting;

[0035] The three materials are separated into purer single materials through two-stage sorting. After sorting, the recovery rate and grade of glass particles, solar cells and welding strips are greater than 95%. Figure 2 shown.

[0036] Embodiment 1

[0037] a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules;

[0038] b. removing the junction box and the aluminum frame of the waste crystalline silicon photovoltaic module by aerobic calcination pretreatment to remove the encapsulant and the backplane to obtain a mixture of glass particles, solar cells and welding ribbons;

[0039] c. The obtained mixture of glass particles, solar cell sheets and welding strips is crushed and sieved to obtain a mixture with a particle size of 0.5-8 cm.

[0040] d. In the first stage of sorting, the mixed material of the three components of screened glass particles, solar cells and solder strips is fed into the active pulsating airflow sorting device at a uniform speed of 50g / min from the upper feeding port of the device. The airflow is introduced from the bottom of the device and the airflow is adjusted to 90m 3 / h, and the pulsation frequency is 0Hz for sorting, collecting glass particles and solar cell mixed materials in the light product, and collecting welding strips in the heavy product;

[0041] e. In the second stage of sorting, the light product obtained after the first stage of sorting, i.e., the glass particles and the mixed material of the solar cell sheets, is fed into the active pulsating airflow sorting device from the upper feeding port of the device at a uniform feeding speed of 50 g / min. The airflow is introduced from the bottom of the device and the airflow is adjusted to 70 m 3 / h, and a pulsation frequency of 1Hz for sorting, collecting solar cells in the light products and glass particles in the heavy products; through two pulsating airflow sorting operations, the three materials of glass particles, solar cells and welding strips are classified, separated and enriched.

[0042] After sorting, the recovery rate and grade of glass particles, solar cells and welding strips are greater than 95%.

[0043] Embodiment 2

[0044] a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules;

[0045] b. removing the junction box and aluminum frame from the waste crystalline silicon photovoltaic modules and subjecting them to oxygen-free pyrolysis pretreatment to remove the encapsulant and backplane to obtain a mixture of glass particles, solar cells and solder strips;

[0046] c. The obtained mixture of glass particles, solar cell sheets and welding strips is crushed and sieved to obtain a mixture with a particle size of 0.5-8 cm.

[0047] d. In the first stage of sorting, the mixed material of the three components of screened glass particles, solar cells and solder strips is fed into the active pulsating airflow sorting device at a uniform speed of 100g / min from the upper feeding port of the device. The airflow is introduced from the bottom of the device and the airflow is adjusted to 100m 3 / h, and a pulsation frequency of 3Hz for sorting, collecting glass particles and solar cell mixed materials in the light product, and collecting welding ribbons in the heavy product;

[0048] e. In the second stage of sorting, the light product obtained after the first stage of sorting, i.e., the glass particles and the mixed material of the solar cell sheets, is uniformly fed into the active pulsating airflow sorting device from the upper feeding port of the device at a feeding speed of 100 g / min. The airflow is introduced from the bottom of the device and the airflow rate is adjusted to 70m 3 / h, and a pulsation frequency of 3Hz for sorting, collecting solar cells in the light products and glass particles in the heavy products; through two pulsating airflow sorting operations, the three materials of glass particles, solar cells and welding strips are classified, separated and enriched.

[0049] After sorting, the recovery rate and grade of glass particles, solar cells and welding strips are greater than 95%.

[0050] Embodiment 3

[0051] a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules;

[0052] b. removing the junction box and aluminum frame from the waste crystalline silicon photovoltaic modules and subjecting them to oxygen-free pyrolysis pretreatment to remove the encapsulant and backplane to obtain a mixture of glass particles, solar cells and solder strips;

[0053] c. The obtained mixture of glass particles, solar cell sheets and welding strips is crushed and sieved to obtain a mixture with a particle size of 0.5-8 cm.

[0054] d. In the first stage of sorting, the mixed material of the three components of screened glass particles, solar cells and solder strips is fed into the active pulsating airflow sorting device at a uniform feeding speed of 150g / min from the upper feeding port of the device. The airflow is introduced from the bottom of the device and the airflow is adjusted to 100m 3 / h, and a pulsation frequency of 5Hz for sorting, collecting glass particles and solar cell mixed materials in the light product, and collecting welding strips in the heavy product;

[0055] e. In the second stage of sorting, the light product obtained after the first stage of sorting, i.e., the glass particles and the mixed material of the solar cell sheets, is fed into the active pulsating airflow sorting device from the upper feeding port of the device at a uniform feeding speed of 150 g / min. The airflow is introduced from the bottom of the device and the airflow is adjusted to 60 m 3 / h, and the pulsation frequency is 5Hz for sorting, collecting solar cells in the light products and collecting glass particles in the heavy products; through two pulsating airflow sorting operations, the three materials of glass particles, solar cells and welding strips are classified, separated and enriched;

[0056] After sorting, the recovery rate and grade of glass particles, solar cells and welding strips are greater than 95%.

Claims

1. A method for sorting different components of crystalline silicon photovoltaic modules using pulsating airflow, characterized in that: First, the waste crystalline silicon photovoltaic modules with the aluminum frame and junction box removed are pre-processed to obtain a mixture of glass particles, solar cells and solder strips; then the mixture is crushed and sieved to obtain a target particle size; finally, the mixture is sorted using a pulsating airflow sorting device, and the classification and enrichment of different components in the mixture is finally achieved by adjusting parameters including airflow, pulsation frequency and feed amount; the specific steps are as follows: a. Remove the junction box and aluminum frame of the discarded crystalline silicon photovoltaic modules; b. Pre-processing the discarded crystalline silicon photovoltaic modules with the junction box and aluminum frame removed to remove the encapsulant and backplane to obtain a mixture of glass particles, solar cells and solder strips; c. The obtained mixed material is screened to obtain a mixed material of three components of glass particles, solar cells and welding strips with a particle size of 0.5-8 cm, and the mixed material with a particle size larger than the target particle size is crushed and screened again; d. Feed the screened mixed material into the pulsating airflow sorting device from the feed port at a uniform speed, and adjust the airflow rate and pulsation frequency for airflow sorting; e. Through two-stage sorting operations, the three materials of glass particles, solar cells and welding ribbons are classified, separated and enriched; f. Collect light products at the discharge port at the upper end of the pulsating airflow sorting device, and collect heavy products at the discharge port at the lower end of the pulsating airflow sorting device. Through two-stage sorting, the classification and enrichment of single materials such as glass particles, solar cells and welding strips can be achieved.

2. A method for sorting different components of a crystalline silicon photovoltaic module using pulsating airflow according to claim 1, characterized in that: In step b, the pretreatment includes anaerobic pyrolysis, aerobic roasting and chemical dissolution.

3. The method for separating different components of a crystalline silicon photovoltaic module by using pulsating airflow according to claim 1, characterized in that: In step c, the crushing includes impact crushing or roller crushing.

4. The method for separating different components of a crystalline silicon photovoltaic module by using pulsating airflow according to claim 1, characterized in that: In step c, the mixture of the three components of glass particles, solar cells and solder strips with a particle size of 0.5-8 cm obtained by screening, because the solder strip is in the form of a wire strip, its length will be greater than 8 cm, but must be less than 20 cm.

5. The method of using pulsating airflow to separate different components of a crystalline silicon photovoltaic module according to claim 1, characterized in that: In step d, the pulsating airflow sorting device is an active pulsating airflow device, the airflow is introduced from the bottom of the device, and the sorting material is fed from the upper part of the device.

6. The method of using pulsating airflow to separate different components of a crystalline silicon photovoltaic module according to claim 1, characterized in that: In step d, the mixed material is fed into the pulsating airflow sorting device from the feed port at a uniform speed, the feed speed is 50-300g / min, and the air flow rate is 50-140m 3 / h, the pulsation frequency is 0-10Hz.

7. The method of using pulsating airflow to separate different components of a crystalline silicon photovoltaic module according to claim 1, characterized in that: In step e, the two-stage sorting operation: In the first stage, pulsating airflow separation is used to separate glass particles, solar cells and welding ribbons. Most of the glass particles and solar cells are collected in the light product, and most of the welding ribbons are collected in the heavy product. In the second stage, pulsating airflow separation is used to separate the glass particles and solar cells. Most of the solar cells are collected in the light products, and most of the glass particles are collected in the heavy products.

Images