Fluorine-free photovoltaic module recycling method

Abstract

The invention discloses a fluoride-free photovoltaic module recycling method which comprises the following steps: material classification: primarily-processed retired photovoltaic panel modules are classified and stored according to the crushing degree of glass plates, and incomplete and curled curled materials and flat primary neat materials are formed; flattening treatment is conducted, specifically, the curled material is flattened to form a secondary neat material; planing and impurity removal are conducted, specifically, planing treatment is conducted on the primary neatening material and the secondary neatening material, and most of the back plates are removed through planing to form planed materials. According to the method, the fluorine-containing back plate is removed in advance through front-end planing and grinding treatment and is recycled in a recycling form, energy consumption and fluorine-containing gas overflow in the follow-up treatment process are greatly reduced, emission of toxic gas is reduced, the whiteness of the recycled glass is more easily improved by the method, and the service life of the glass is prolonged. And the whole process flow does not adopt a high-energy-consumption process, so that the energy consumption is low, the pollution is avoided, the process is short-range and efficient, the engineering application is feasible, and the economic benefit is considerable.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling retired photovoltaic panels, and in particular to a method for recycling photovoltaic modules without fluorine. Background Art

[0002] In recent years, the photovoltaic industry has developed rapidly as a clean and renewable energy source. my country's photovoltaic industry scale and market application have ranked first in the world. Photovoltaic modules are composed of glass, packaging materials, silicon crystal cells, backplanes, aluminum frames, wire boxes and EVA glue. The life of photovoltaic modules is about 25 to 30 years. If a large number of retired photovoltaic modules are not properly, scientifically and effectively handled and utilized, it will inevitably cause environmental pollution and waste of resources. my country and even the world are about to enter the retirement tide of photovoltaic modules, and the rational resource recycling of photovoltaic modules is imminent.

[0003] At present, there are several existing methods for recycling retired photovoltaic panels: high-temperature incineration or pyrolysis, chemical treatment, physical crushing and sorting, etc.

[0004] Chemical treatment methods generally use acid, alkali and other solutions to treat photovoltaic modules. Although this method can recover valuable materials relatively cleanly, it has a long reaction time and a long process completion cycle, and produces a lot of wastewater during the production process, which is not environmentally friendly.

[0005] The physical crushing and sorting method is to remove the junction box and aluminum frame, roll the photovoltaic glass to recover most of the glass materials, and crush the remaining laminated parts for physical sorting. This method can efficiently sort the glass backplane and battery cell particles, but the purity of each valuable material is very low, and it is basically impossible to reuse or the reuse value is not high for downstream manufacturers.

[0006] Among them, high-temperature incineration pyrolysis can effectively treat the EVA glue and backboard, and the sorting products obtained are relatively clean. However, the backboard accounts for a considerable proportion of the entire photovoltaic panel components. The pyrolysis of the photovoltaic backboard consumes a lot of energy, and the backboard is easy to pyrolyze to produce a large amount of fluorine-containing toxic gases, which causes great harm to the environment and operators. At the same time, the heat treatment of the fluorine-containing backboard needs to be carried out in an inert gas atmosphere, which causes organic components to penetrate into the photovoltaic glass, reducing the whiteness of the glass, causing the downstream enterprises to reduce the value of glass recycling. Summary of the invention

[0007] The present invention provides a method for fluorine-free recycling of photovoltaic modules to solve the above technical problems in the prior art.

[0008] The technical solution of the present invention is achieved in this way:

[0009] A method for recycling photovoltaic modules without fluorine, comprising:

[0010] Material classification: The retired photovoltaic panel components after primary processing are classified and stored according to the degree of glass plate breakage, forming incomplete and curled curled materials and flat primary neat materials;

[0011] Flattening treatment: Flatten the curled material to form secondary neat material;

[0012] Planing and removing impurities: Planing is performed on the primary and secondary trimming materials, and most of the back panels are removed by planing to form planed materials;

[0013] Grinding and removing impurities: Grinding the planed material to remove the remaining backing plate on the initial planed material to form the planed material;

[0014] Heat treatment separation: heat treatment is performed on the planed material to separate the metal parts from other materials to form crushed materials;

[0015] Material screening: glass and silicon wafers are taken out from the large components in the crushed material, and the broken components in the crushed material are screened to select silicon wafers;

[0016] Material salvage: The remaining parts of the broken components are salvaged using slag removal equipment to select the solder strips in the glass.

[0017] Preferably, the planing depth in the planing and impurity removal step is 0.05-0.1 mm from the battery cell.

[0018] Preferably, the grinding and polishing method in the grinding and impurity removal step is automatic grinding and polishing with a sandpaper roller, and the grinding and polishing depth is 0.05-0.1mm. Specifically, automatic grinding and polishing is performed using a sandpaper roller with a wire brush or a mesh size of less than 400.

[0019] Preferably, the heat treatment temperature in the heat treatment separation step is 550-650° C., and the heat treatment time is 30-120 minutes.

[0020] Preferably, the screening process in the material screening step is grid screen screening, and the size of the grid screen is 0.5-2 mm.

[0021] Beneficial effects:

[0022] The present invention removes the fluorine-containing backplane in advance through front-end planing and grinding treatment and recycles it in a form that can be recycled, greatly reducing energy consumption and overflow of fluorine-containing gases in subsequent treatment processes, and reducing emissions of toxic gases. This method makes it easier to improve the whiteness of the recycled glass, reducing pre-treatment costs for downstream industries. The entire process does not use high-energy consumption processes, has low energy consumption and is pollution-free, has a short and efficient process, is feasible for engineering applications, and has considerable economic benefits.

[0023] The present invention can advance the separation of the fluorine-containing backsheet to before the heat treatment, which can not only efficiently recover the backsheet but also avoid the fluorine-containing backsheet from being pyrolyzed to produce a large amount of fluorine-containing gas during the heat treatment stage. The backsheet can be efficiently and cleanly separated without using high-temperature pyrolysis, avoiding the high-energy consumption and high-pollution process of using high-temperature pyrolysis or chemical reagents to react and treat the fluorine-containing backsheet, greatly reducing the energy consumption of the production line, and no toxic gas is generated, reducing the generation of three wastes, thereby improving the economic efficiency of industrial production and providing feasibility for the construction of subsequent production lines and facilitating on-site treatment of photovoltaic components.

[0024] The present invention can relatively completely recycle photovoltaic glass with high value, greatly improve the whiteness of photovoltaic glass compared to the inert gas heat treatment process, and increase the value of glass recycling for downstream enterprises. The recycling rate of photovoltaic glass reaches more than 95%, and the recycling rate of backplane reaches more than 98%. Compared with the pure crushing and sorting process, the invention can greatly improve the recycling rate and purity of the recycled product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The present invention is a process flow chart of a method for fluorine-free recycling of photovoltaic modules according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0028] According to an embodiment of the present invention, a method for fluorine-free recycling of photovoltaic modules is provided.

[0029] like Figure 1 As shown, in this optional embodiment, the method for fluorine-free recycling of photovoltaic modules according to an embodiment of the present invention includes:

[0030] Step S101, material classification: the retired photovoltaic panel components after primary processing are classified and stored according to the degree of breakage of the glass plates to form incomplete and curled curled materials and flat primary trimmed materials;

[0031] Step S103, flattening treatment: flattening the curled material to form a secondary neat material;

[0032] Step S105, planing and removing impurities: planing the primary trimming material and the secondary trimming material, and planing and removing most of the back plate to form planed material;

[0033] Step S107, grinding and removing impurities: grinding and processing the planed material, grinding and planing away the remaining backing plate on the initial planed material to form a planed material;

[0034] Step S109, heat treatment separation: heat treatment is performed on the shavings to separate the metal parts in the shavings from other materials to form crushed materials;

[0035] Step S111, material screening: glass and silicon wafers are taken out from the large components in the crushed material, and the broken components in the crushed material are screened to select silicon wafers;

[0036] Step S113, material salvage: using slag salvaging equipment to take out the soldering ribbon in the glass.

[0037] In this optional embodiment, the planing depth in the planing and impurity removal step is 0.05-0.1 mm from the battery cell.

[0038] In this optional embodiment, the grinding and polishing method in the grinding and impurity removal step is automatic grinding and polishing with a sandpaper roller, and the grinding and polishing depth is 0.05-0.1mm. Specifically, automatic grinding and polishing is performed using a sandpaper roller with a wire brush or a mesh size of less than 400.

[0039] In this optional embodiment, the heat treatment temperature in the heat treatment separation step is 550-650° C., and the heat treatment time is 30-120 minutes.

[0040] In this optional embodiment, the screening process in the material screening step is grid screen screening, and the size of the grid screen is 0.5-2 mm.

[0041] In order to facilitate understanding of the above technical solutions of the present invention, the above technical solutions of the present invention are further described below through a number of specific embodiments.

[0042] Embodiment 1

[0043] like Figure 1 As shown, in specific applications, the process of the method for fluorine-free recycling of photovoltaic modules can be as follows:

[0044] Material classification: The retired photovoltaic panel components after primary processing are classified and stored according to the degree of glass plate breakage, forming curled materials with broken and curled glass plates and primary neat materials with relatively complete glass plates;

[0045] Flattening treatment: Flatten the curled material to form secondary neat material;

[0046] Planing and removing impurities: The primary and secondary trimming materials are planed with a planer. The planing depth is 0.1mm from the battery cell to remove most of the backplane to form planed materials.

[0047] Grinding and removing impurities: The planed material is ground and polished with a wire brush roller at a depth of 0.05mm to grind off the remaining backing plate on the initial planed material to form the planed material;

[0048] Heat treatment separation: The photovoltaic modules after grinding and polishing are heat treated at 550℃ in a heating furnace for 120 minutes to separate the metal parts in the planed materials from other materials to form fragmented materials, and then air is introduced and the exhaust gas is connected to the waste gas treatment system. After leaving the furnace, air is used to blow away carbonized impurities;

[0049] Material screening: glass, silicon wafers and solder strips are taken out from the large components in the crushed material, and the broken components in the crushed material are screened with a 0.5 mm grid screen to select silicon wafers;

[0050] Material salvage: The remaining parts of the broken components are salvaged using slag removal equipment to select the solder strips in the glass.

[0051] Embodiment 2

[0052] like Figure 1 As shown, in specific applications, the process of the method for fluorine-free recycling of photovoltaic modules can be as follows:

[0053] Material classification: The retired photovoltaic panel components after primary processing are classified and stored according to the degree of glass plate breakage, forming curled materials with broken and curled glass plates and primary neat materials with relatively complete glass plates;

[0054] Flattening treatment: Flatten the curled material to form secondary neat material;

[0055] Planing and removing impurities: The primary and secondary trimming materials are planed with a planer. The planing depth is 0.05mm from the battery cell to remove most of the backplane to form planed materials.

[0056] Grinding and removing impurities: The planed material is ground and polished with a 400-mesh sand roller to a depth of 0.1 mm, and the remaining backing plate on the initial planed material is removed to form the planed material;

[0057] Heat treatment separation: The photovoltaic modules after grinding and polishing are heat treated at 650℃ in a heating furnace for 30 minutes to separate the metal parts in the planed materials from other materials to form fragmented materials, and then air is introduced and the exhaust gas is connected to the exhaust gas treatment system. After leaving the furnace, air is used to blow away carbonized impurities;

[0058] Material screening: glass, silicon wafers and solder strips are taken out from the large components in the crushed material, and the broken components in the crushed material are screened with a 2 mm grid screen to select silicon wafers;

[0059] Material salvage: The remaining parts of the broken components are salvaged using slag removal equipment to select the solder strips in the glass.

[0060] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recycling photovoltaic modules without fluorine, characterized in that: include: Material classification: The retired photovoltaic panel components after primary processing are classified and stored according to the degree of glass plate breakage, forming incomplete and curled curled materials and flat primary neat materials; Flattening treatment: Flatten the curled material to form secondary neat material; Planing and removing impurities: Planing is performed on the primary and secondary trimming materials, and most of the back panels are removed by planing to form planed materials; Grinding and removing impurities: Grinding the planed material to remove the remaining backing plate on the initial planed material to form the planed material; Heat treatment separation: heat treatment is performed on the planed material to separate the metal parts from other materials to form crushed materials; Material screening: glass and silicon wafers are taken out from the large components in the crushed material, and the broken components in the crushed material are screened to select silicon wafers; Material salvage: The remaining parts of the broken components are salvaged using slag removal equipment to select the solder strips in the glass.

2. The method for fluorine-free recycling of photovoltaic modules according to claim 1, characterized in that: The planing depth in the planing and impurity removal step is 0.05-0.1 mm from the battery cell.

3. The method for recycling photovoltaic modules without fluorine according to claim 1, characterized in that: The grinding and polishing method in the grinding and impurity removal step is automatic grinding and polishing with a sandpaper roller, and the grinding and polishing depth is 0.05-0.1mm. Specifically, automatic grinding and polishing is performed using a sandpaper roller with a wire brush or a mesh number below 400.

4. The method for fluorine-free recycling of photovoltaic modules according to claim 1, characterized in that: The heat treatment temperature in the heat treatment separation step is 550-650° C., and the heat treatment time is 30-120 minutes.

5. The method for fluorine-free recycling of photovoltaic modules according to claim 1, characterized in that: The screening process in the material screening step is grid screen screening, and the size of the grid screen is 0.5-2 mm.

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