Method and apparatus for separating photovoltaic module materials

Abstract

A method for separating materials of a photovoltaic (PV) module and an associated apparatus are disclosed, the method including: providing at least one sieve and at least one collecting portion, the sieve having a receiving portion and a sieving screen, the sieving screen including a plurality of openings, such that fragments of material having a size below the opening size of the plurality of openings can pass from the receiving portion through the sieving screen to reach the collecting portion; introducing a load into the receiving portion, the load including a first load portion and a second load portion, the first load portion including fragments of a first material of the photovoltaic module, and the second load portion including fragments of a second material of the photovoltaic module, the second material being a different type of material from the first material; adding one or more sieving aids to the receiving portion; and agitating the at least one sieve, the one or more sieving aids mechanically interacting with the load to assist in reducing the plurality of fragments of the first material to a size below the opening size.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Australian Provisional Patent Application No. 2022903639, filed November 30, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to methods and related apparatus for separating materials. In particular, but not necessarily exclusively, the present disclosure relates to methods and apparatus for separating materials in photovoltaic modules, for example, for recycling purposes. [Background technology]

[0003] Photovoltaic (PV) modules, also known as solar panels, function to convert sunlight into electrical energy and are therefore a valuable alternative to fossil fuel-based energy generation. PV modules typically include a photovoltaic layer comprising a PV silicon wafer encapsulated between two protective sheets, which are held in place over the PV silicon wafer by an encapsulant layer, such as an ethylene-vinyl acetate (EVA) layer. The photovoltaic layer, protective sheets, and encapsulant layer are usually set within a frame, such as an aluminum frame. Metallization elements, which function as electrical conductors, are typically screen-printed onto the surface of the PV silicon wafer. One or both of the protective sheets typically comprises glass.

[0004] Due to defects related to the natural wear of PV modules, such as layer delamination and grinding burns, the average lifespan of PV modules is limited. PV modules that reach the end of their lifespan must be discarded and replaced. Currently, there are no standard procedures for the disposal of PV module waste, and in most regions, waste ends up in landfills.

[0005] Current processes used to recycle PV module materials involve disassembly of the aluminum frame and stripping of the protective sheet and encapsulant layer using mechanical, thermal, and / or chemical methods. The disassembly and stripping process often results in damage and breakage of the glass and PV silicon wafer, resulting in the mixing of fragments of both materials. Fragments of glass and PV silicon wafer material in a mixture are difficult to separate, making recycling challenging. Current techniques used to separate the fragments of material include, for example, electrostatic separation and density separation, which attempt to separate fragments based on differences in their physical properties.

[0006] In electrostatic separation techniques, materials are sorted based on differences in their electrical conductivity, and therefore electrostatic properties. PV solar modules are shredded into fine particles and then fed into roller separators. The particles acquire different electrical charges upon physical contact with the rollers, resulting in different tendencies for the particles to fall off the rollers, enabling the separation of the materials. While electrostatic separation has great potential for dealing with large amounts of waste, it is relatively ineffective at separating glass from other conductive or semiconducting particles because the weight of glass particles is relatively heavy, meaning that the momentum gained by glass particles during rotation exceeds the force of electrostatic forces.

[0007] Density separation separates materials based on their mass-to-volume ratio. PV solar modules are shredded into fine particles and sent to a density separation device containing a fluid. Material separation is achieved by using an intermediate-density fluid, so that particles of materials with one density range float in the fluid and particles of materials with a second density range sink. Water is one of the most commonly used fluids in density separation applications. However, in PV module recycling, most of the materials contained in PV modules have relative densities greater than 1, making water no longer a suitable and applicable solution. For example, the relative densities of silicon, glass, aluminum, copper, and silver are 2.33, 2.5, 2.7, 8.9, and 10.4, respectively. While it is possible to use other high-density fluids as intermediate fluids, this could significantly increase the operational costs and risks of the separation process in PV recycling.

[0008] Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification should not be construed as an admission that any or all of such matters form part of the prior art base or were common general knowledge in the art to which this disclosure pertains by virtue of their existence prior to the priority date of each of the appended claims. Summary of the Invention

[0009] According to one aspect, the present disclosure provides a method for separating materials in a photovoltaic (PV) module, comprising: Providing at least one sieve and at least one collecting section, the sieve comprising a receiving section and a sieving screen, the sieving screen including a plurality of openings, and allowing material fragments having a size smaller than the opening size of the plurality of openings to pass from the receiving section through the sieving screen and reach the collecting section; introducing a load into the receiving portion, the load including a first load portion and a second load portion, the first load portion including a piece of a first material of the photovoltaic module, and the second load portion including a piece of a second material of the photovoltaic module, the second material being a different type of material than the first material; adding one or more sieving aids to the receiving portion; agitating at least one sieve, wherein one or more sieving aids mechanically interact with the load to assist in reducing the plurality of pieces of the first material to a size below the aperture size.

[0010] In some embodiments, the agitation of the at least one sieve is such that a portion of the first load portion passes from the receiving portion through the sieving screen to reach the collection portion, and this portion of the first load portion is larger in size than any portion of the second load portion that passes from the receiving portion through the sieving screen to reach the collection portion.

[0011] In some embodiments, the agitation of the at least one sieve is such that a majority of the first load portion passes from the receiving portion through the sieving screen to the collection portion, and a majority of the second load portion remains in the receiving portion.

[0012] In some embodiments, the majority of the first loading portion comprises at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of the first loading portion.

[0013] In some embodiments, the majority of the second loading portion comprises at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or at least 98% by weight of the second loading portion.

[0014] In some embodiments, the reduction in size of the plurality of pieces of the first material below the aperture size is faster than any reduction in size of the plurality of pieces of the second material below the aperture size.

[0015] In some embodiments, one or more of the sieving aids have the shape of a ball, sphere, ellipsoid, cube, cuboid, cylinder, cone, or pyramid.

[0016] In some embodiments, one or more of the sieving aids comprises stainless steel, rubber, plastic, or ceramic.

[0017] In some embodiments, adding one or more sieving aids to the receiving portion comprises adding at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 40, at least 50, at least 60, at least 100, at least 200, at least 500, at least 1000, at least 10,000, 2-10,000, 10-1,000, 100-500, 500-1,000, 200-800, 2-100, 5-75, or 10-60 sieving aids to the receiving portion.

[0018] In some embodiments, the fragments of the first material are fragments of photovoltaic silicon wafers of a PV module.

[0019] In some embodiments, the first load portion comprises a metallization element of a photovoltaic module, or a fragment of a metallization element, attached to or associated with the fragment of a photovoltaic silicon wafer.

[0020] In some embodiments, the metallization elements include one or more of silver, aluminum, tin, copper, zinc, or lead.

[0021] In some embodiments, the piece of second material is a piece of glass from a photovoltaic module.

[0022] In some embodiments, agitating the at least one sieve comprises intermittently agitating the sieve.

[0023] In some embodiments, agitating the at least one sieve comprises agitating the sieve consecutively during each of a plurality of first time periods, each consecutive first time period of the plurality of first time periods being separated by a respective second time period, during each second time period the sieve is substantially not agitated.

[0024] In some embodiments, during the first period, the one or more sieving aids undergo a vibrational motion within the receiving portion to mechanically interact with the load.

[0025] In some embodiments, during the second period of time, the vibrational motion of the one or more sieving aids is discontinued and the sieving aids move substantially horizontally within the receiving portion.

[0026] In some embodiments, the first period of time is one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes, and the second period of time is one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes.

[0027] In some embodiments, the total stirring period, i.e., the total first period, is at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 30 minutes, or at least 1 hour.

[0028] In some embodiments, the first period of time is at least 3 seconds, the second period of time is at least 3 seconds, and the total stirring period is at least 5 minutes.

[0029] In some embodiments, the agitation of at least one sieve is such that the sieve has an amplitude of vertical motion of at least 1 mm, at least 1.5 mm, at least 2 mm, at least 2.5 mm, at least 3 mm, at least 5 mm, at least 10 mm, at least 20 mm, or at least 50 mm.

[0030] In some embodiments, the method includes providing a plurality of sieves in a vertically stacked configuration, wherein a receiving portion of at least one lower sieve of the plurality of sieves provides a collection portion for at least one upper sieve of the plurality of sieves located above the at least one lower sieve.

[0031] In some embodiments, the sieving screens of the plurality of sieves have decreasing opening sizes from top to bottom of the vertically stacked configuration of the plurality of sieves.

[0032] In some embodiments, one or more sieving aids are added to the receiving portion of two or more of the plurality of sieves.

[0033] In some embodiments, the amount of sieving aid and / or the physical parameters of the sieving aid added to each of the receiving portions are different.

[0034] According to one aspect of the present disclosure, there is provided a photovoltaic (PV) module material separation apparatus, comprising: at least one sieve and at least one collecting section, wherein the sieve comprises a receiving section and a sieve screen, the sieve screen comprising a plurality of openings, such that fragments of material having a size smaller than the opening size of the plurality of openings can pass from the receiving section through the sieve screen to reach the collecting section, the receiving section being adapted to receive a load comprising a first load section and a second load section, the first load section comprising fragments of a first material of a photovoltaic module, the second load section comprising fragments of a second material of the photovoltaic module, and the second material being a different type of material from the first material; one or more sieving aids configured to be received in the receiving portion; A photovoltaic (PV) module material separation apparatus is provided, comprising: an agitation mechanism configured to agitate at least one sieve, wherein one or more sieving aids mechanically interact with the load to assist in reducing a plurality of pieces of a first material to a size below the mesh size.

[0035] The PV module material separation apparatus may be used, for example, in the methods described above with respect to the previous embodiment, and any one or more of the components of the apparatus may be configured as described with respect to the previous embodiment.

[0036] Although the methods and apparatus are described above in relation to the separation of materials in photovoltaic modules, the methods and apparatus can be used for the separation of other materials.

[0037] Following this, according to one aspect, the present disclosure provides a method of separating materials, comprising: Providing at least one sieve and at least one collecting section, the sieve comprising a receiving section and a sieving screen, the sieving screen including a plurality of openings, and allowing material fragments having a size smaller than the opening size of the plurality of openings to pass from the receiving section through the sieving screen and reach the collecting section; introducing a load into the receiving portion, the load including a first load portion and a second load portion, the first load portion including pieces of a first material and the second load portion including pieces of a second material, the second material being a different type of material than the first material; adding one or more sieving aids to the receiving portion; agitating at least one sieve, wherein one or more sieving aids mechanically interact with the load to assist in reducing the plurality of pieces of the first material to a size below the aperture size.

[0038] Furthermore, according to another aspect of the present disclosure, there is provided a material separation apparatus, comprising: at least one sieve and at least one collecting section, wherein the sieve comprises a receiving section and a sieve screen, the sieve screen comprising a plurality of openings, such that fragments of material having a size smaller than the opening size of the plurality of openings can pass from the receiving section through the sieve screen to reach the collecting section, the receiving section being adapted to receive a load comprising a first load section and a second load section, the first load section comprising fragments of the first material, the second load section comprising fragments of the second material, the second material being a different type of material from the first material; one or more sieving aids configured to be received in the receiving portion; and an agitation mechanism configured to agitate the sieve such that one or more sieving aids mechanically interact with the load to assist in reducing a plurality of fragments of the first material to a size below the aperture size.

[0039] Throughout this specification, the word "comprise" or variations thereof (e.g., "comprises" or "comprising") will be understood to mean the inclusion of a stated element, integer, or step, or group of elements, integers, or steps, but not the exclusion of any other element, integer, or step, or group of elements, integers, or steps.

[0040] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0041] [Figure 1] An exploded view of a PV module is shown. [Figure 2] 1 shows a flowchart of a method for separating materials in a PV module according to one embodiment of the present disclosure. [Figure 3] 1 illustrates a PV module material separation apparatus according to an embodiment of the present disclosure, including a load in a sieve receiving portion of the apparatus. [Figure 4] 4 shows the apparatus of FIG. 3 after agitation of the sieves. [Figure 5] 1 illustrates a PV module material separation apparatus according to an embodiment of the present disclosure, including a load in a sieve receiving portion of the apparatus. [Figure 6] 1 illustrates different sieving aids according to embodiments of the present disclosure. [Figure 7A] 1 shows an image of a fragment of material in a 5 mm sieve section after an initial sieving process without the use of a sieving aid. [Figure 7B] 1 shows an image of a fragment of material in a 5 mm sieve section after the sieving process using a sieving aid. [Figure 8A] 1 shows an image of a fragment of material in the 3.15 mm sieve section after the initial sieving process without the use of a sieving aid. [Figure 8B] 1 shows an image of a fragment of material in the 3.15 mm sieve section after the sieving process using a sieving aid. [Figure 9A] 1 shows an image of a fragment of material in a 1 mm sieve section after an initial sieving process without the use of a sieving aid. [Figure 9B] 1 shows an image of a fragment of material in a 1 mm sieve section after a sieving process using a sieving aid. [Figure 10] 1 shows an image of concentrated PV silicon wafer fragments in a 0.5 mm sieve section after the sieving process using a sieving aid. DETAILED DESCRIPTION OF THE INVENTION

[0042] One or more embodiments of the present disclosure provide methods and apparatus for separating materials in PV modules, for example, as part of a recycling process.

[0043] An example of a PV module 100 that can be subject to the methods and apparatus of the present disclosure is shown in FIG. 1. The PV module 100 includes a photovoltaic layer 110 (which may include one or more photovoltaic layers), which in turn includes a PV silicon wafer. First and second protective sheets 120, 130 are positioned on either side of the photovoltaic layer 100 and secured to opposite sides of the photovoltaic layer 100 using first and second encapsulant layers 140, 150, respectively. The first and second encapsulant layers may be ethylene-vinyl acetate (EVA) layers, although other thermoplastic resins may be used as encapsulants. The assembly of the photovoltaic layer 110, first and second protective sheets 120, 130, and encapsulant layers 140, 150 is held in a frame 160, such as an aluminum frame.

[0044] One or both of the first and second protective sheets 120, 130 may comprise glass, allowing sunlight to pass through the glass to reach the photovoltaic layer 100. The glass may include soda-lime glass, borosilicate glass, and lead crystal glass, or any other type of glass typically used in PV modules. The glass may be tempered glass.

[0045] Metallization elements 115, such as bus bars, conductive fingers, and contacts, are attached to or otherwise associated with the PV silicon wafer of photovoltaic layer 110 for the purpose of conducting electricity generated through photovoltaic layer 110. Metallization elements 115 may include one or more of silver, aluminum, tin, copper, zinc, or lead, or any other material that can be used as an electrical conductor in a photovoltaic module to conduct electricity generated through the PV silicon wafer.

[0046] At the end of the PV module 100's life, or otherwise, the PV module 100 may be disassembled, and the frame 160 may be removed from the other components of the PV module 100. The protective sheets 120, 130 and encapsulant layers 140, 150 may then be peeled from the photovoltaic layer 110 using mechanical, thermal, and / or chemical methods. The disassembly and / or peeling process often damages and destroys the glass in at least one of the first and second protective sheets 120, 130, as well as destroying the PV silicon wafer, resulting in glass fragments intermixed with fragments of the PV silicon wafer and, in some cases, with fragments of the associated metallization element 115. Methods and apparatus according to embodiments of the present disclosure may be used, for example, as part of a PV module recycling process or otherwise, to separate fragments of different materials. The methods and apparatus may enable recovery of materials, such as silicon and / or any one or more metals present in the PV module, increasing recycling yields.

[0047] 2 , in a method 200 for separating materials of a PV module according to an embodiment of the present disclosure, a load and one or more sieving aids are added to a receiving portion of a sieve at 210. The sieve includes a receiving portion and a sieving screen, the sieving screen including a plurality of openings, and fractions of material having a size below the opening size of the plurality of openings can pass from the receiving portion through the sieving screen to reach a collecting portion. The load includes a first load portion and a second load portion, the first load portion including fractions of a first material of the photovoltaic module, and the second load portion including fractions of a second material of the photovoltaic module, the second material being a different type of material than the first material.

[0048] At 220, the sieve is agitated and one or more sieving aids mechanically interact with the load to assist in reducing the size of the plurality of pieces of the first material below the opening size of the sieving screen.

[0049] The sieve agitation may be such that a portion of the first load portion passes from the receiving portion through the sieving screen to reach the collection portion, the portion of the first load portion being greater in total size than any portion of the second load portion that passes from the receiving portion through the sieving screen to reach the collection portion. For example, the amount of the first load portion that passes through the sieving screen to reach the collection portion as a weight percentage (wt %) of the total first load portion introduced into the receiving portion may be greater than the amount of the second load portion that passes through the sieving screen to reach the collection portion as a weight % of the total second load portion introduced into the receiving portion.

[0050] The sieve agitation may be such that a majority of the first load portion passes from the receiving portion through the sieving screen to the collection portion, and a majority of the second load portion remains in the receiving portion. The majority of the first load portion may comprise at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of the first load portion, and the majority of the second load portion may comprise at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of the second load portion.

[0051] FIG. 3 shows a PV module material separation apparatus 300 according to an embodiment of the present disclosure, which may be used, for example, to implement the method described with respect to FIG. 2 , optionally after disassembly and stripping of a PV module 100 of the type described above with respect to FIG. 1 . Apparatus 300 includes a sieve 305 having a receiving portion 310 and a sieving screen 320. A collection portion 330 of apparatus 300 is located below sieve 305. Sieving screen 320 includes a plurality of openings 321, and material fragments having a size below the opening size of the plurality of openings 321 can pass from receiving portion 310 through sieving screen 320 to collection portion 330. In some embodiments, collection portion 330 may be a pan of a sieving apparatus as shown in FIG. 3 .

[0052] The apparatus 300 further includes an agitation mechanism 340 for agitating (e.g., vibrating) the sieve 305. The agitation mechanism 340 may include a vibration plate 341 for vibrating the vibration plate 341 and a motor 342. The agitation mechanism may vibrate the sieve 305 vertically and / or horizontally. Additionally or alternatively, the agitation mechanism 340 may agitate the sieve 305 by applying a circular motion and / or by tapping the sieve 305. The agitation mechanism 340 may be positioned below the sieve 305, but in alternative embodiments, may be positioned above or to the side of the sieve 305. The agitation may agitate at least the receiving portion 310 of the sieve 305 and the sieving screen 320. A controller 343 is associated with the agitation mechanism and may control the motor 342 and, therefore, agitation parameters such as the amplitude and duration of the vibration. Some or all of apparatus 300 can be provided by, for example, a commercially available vertical sieve shaker, horizontal sieve shaker, tap shaker, or rotary tap shaker. The agitation of sieve 305 can be such that sieve 305 has an amplitude of vertical motion (and / or horizontal motion) of, for example, at least 1 mm, at least 1.5 mm, at least 2 mm, at least 2.5 mm, at least 3 mm, at least 5 mm, at least 10 mm, at least 20 mm, or at least 50 mm. The amplitude of vertical motion (and / or any other motion) of sieve 305 can be increased, for example, when the method is performed using a larger sieve that can accommodate a larger load.

[0053] FIG. 3 shows load 350 including first load portion 360 and second load portion 370 after being added to receiving portion 310 of sieve 305. First load portion 360 includes fragments of a first material 361 of a photovoltaic module, and second load portion 370 includes fragments of a second material 362 of a photovoltaic module, the second material being a different type of material than the first material. The fragments of first material 361 may be fragments of PV silicon wafers, and the fragments of second material 362 may be fragments of glass (fragments of glass layers). In addition to the fragments of PV silicon wafers, first load portion 360 may include fragments of a third material 363, which may include metallization elements 363, as described with respect to FIG. 1.

[0054] In addition to the load 350, one or more sieving aids 380, and in this example, multiple sieving aids 380, are also added to the receiving portion 310 of the sieving unit 305, either before or after the addition of the load 350. The sieving aids 380 are additives to the sieving process that are not part of the PV module being processed. During the agitation of the sieve 305, the sieving aids 380 are configured to mechanically interact (e.g., impact, crush, crush, and / or pulverize) with the load 350 to assist in reducing the plurality of pieces of at least the first material 361 and optionally the third material 363 to a size below the aperture size. The reduction of the plurality of pieces of the first material 361 and optionally also the third material 363 to a size below the aperture size may be faster than any reduction of the plurality of pieces of the second material 362 to a size below the aperture size. In general, fragments of the first material 361 (and optionally the third material 363) may be reduced in size more easily than fragments of the second material 362, for example, due to the fragments of the first material 361 (and optionally the third material 363) being more likely to break as a result of mechanically interacting with the sieve 305 and the sieving aid 380 than fragments of the second material 362. However, this may not be necessary if the fragments of the first material 361 (and optionally the third material 363) are already closer to the threshold size than the fragments of the second material 362, prior to mechanically interacting with the sieving aid 380.

[0055] 4 , the agitation of sieve 305 causes a portion of first load portion 360 (including fragments of first material 361 and optionally fragments of third material 363) to pass from receiving portion 310 through sieving screen 320 to collection portion 330, this portion of first load portion 360 having a larger total size than any portion of second load portion (including fragments of second material 362) that passes from receiving portion 310 through sieving screen 320 to collection portion 330. For example, the amount of first load portion 360, in terms of weight percentage (wt %) of the total first load portion added to receiving portion 310, that passes through sieving screen 320 to collection portion 330 may be greater than the amount of second load portion 370, in terms of wt % of the total second load portion added to receiving portion 310, that passes through sieving screen 320 to collection portion 330.

[0056] The agitation of sieve 305 may be such that a majority of first load portion 360 may pass from receiver portion 310 through sieving screen 320 to collection portion 330, and a majority of second load portion 370 may remain in receiver portion 310. The majority of first load portion 360 may comprise at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of first load portion 360, and the majority of second load portion 370 may comprise at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of second load portion.

[0057] A variety of different sieving parameters may be selected to optimize the desired reduction in size of the fragments of the first material 361 and optionally also the third material 363 so that the first load portion passes more easily from the receiving portion 310 through the openings 321 of the sieving screen 320 to the collection portion 330 compared to the second load portion. The sieving parameters selected may include the amount of sieving aid 380 added to the receiving portion 310, the weight, density, and / or size (e.g., diameter or volume) of the sieving aid 380, the shape of the sieving aid 380, the material of the sieving aid 380, or otherwise. The selected parameters may depend on factors such as the weight and / or components of the load 350 and the dimensions of the sieve 305.

[0058] For example, one or more of the sieving aids 380 may have the shape of a ball (including a sphere 381 or an ellipsoid 382), a cube 383, a rectangular solid 384, a cylinder 385, a cone 386, or a pyramid 387, see Figure 6. As another example, one or more of the sieving aids 370 may include stainless steel, rubber, plastic, ceramic, or any other material capable of achieving the desired size reduction of different materials. The amount of sieving aid 380 added to receiving portion 310 can be, for example, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 40, at least 50, at least 60, at least 100, at least 200, at least 500, at least 1000, at least 10,000, 2-10,000, 10-1,000, 100-500, 500-1,000, 200-800, 2-100, 5-75, or 10-60 sieving aids 380. The diameter of one or more of the sieving aids 380 (e.g., if in the shape of a ball or sphere) can be, for example, at least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, at least 50 mm, at least 100 mm, 5-100 mm, 10-50 mm, 3-20 mm, 4-15 mm, or 5-10 mm. For example, a greater amount of sieving aid 380 having a larger size, diameter, weight, and / or density, and / or sieving aid 380 can be added to the receiving portion of a larger sieve that can accommodate a larger load.

[0059] In the above-described method and apparatus, agitating the sieve 305 may include intermittently agitating the sieve 305. Intermittently agitating the sieve 305 may include continuously agitating the sieve 305 during each of a plurality of first time periods, each successive first time period among the plurality of first time periods being separated by a respective second time period, during which the sieve is not substantially agitated. During the first time periods, the one or more sieving aids 380 may be subjected to a vibrational motion within the receiving portion 310 (e.g., a vertical and / or horizontal vibrational motion within the receiving portion 310) to mechanically interact with the load 350. During the second time periods, the vibrational motion of the one or more sieving aids 380 may be interrupted, and the sieving aids 380 may move substantially horizontally within the receiving portion 310. This may enhance contact between the sieving aid 380 and the pieces of the first material 361 and optionally the third material 363, for example, by allowing the sieving aid 380 to be relocated to different areas within the sieve during the second period of time.

[0060] The first period of time can be, for example, one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes, and the second period of time can be, for example, one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes. The first and second periods of time can be extended, for example, when the method is performed using a larger sieve that can accommodate a larger load.

[0061] The total agitation period, i.e., the sum of the first period, can be, for example, at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 20 minutes, at least 30 minutes, or at least 1 hour. For example, the first period can be at least 3 seconds, the second period can be at least 3 seconds, and the total agitation period can be at least 5 minutes. For example, the total agitation period can be extended when the method is performed using a larger sieve that can accommodate a larger load.

[0062] 3 and 4, a single sieve 305 is provided having a receiving portion 310 and a sieving screen 320, and positioned only above a single collection portion 330. In an alternative embodiment, as shown in FIG. 5, an apparatus 400 may be provided that includes multiple sieves 405a, 405b, 405c, each including a respective receiving portion 410a, 410b, 410c and a respective sieving screen 420a, 420b, 420c, and each positioned above a respective collection portion 430a, 430b, 430c. The sieves 405a, 405b, 405c are stacked vertically above an agitation mechanism 440, which may be operable to agitate all of the sieves 405a, 405b, 405c simultaneously and in a manner the same or similar to the agitation mechanism 340 of the apparatus 300 described above. The sieving screens 420a, 420b, 420c may have apertures that decrease in size from the top sieve to the bottom sieve in the stack. In this configuration, one or more receiving portions 410b, 410c of lower sieves 405b, 405c in the stack may act individually or in combination as one or more collecting portions 430a, 430b for the sieves 405a, 405b located higher in the stack. A pan may serve as the collection portion 430c for the bottom sieve 403c. Part or all of the apparatus 400 may be provided by, for example, a commercially available vertical sieve shaker, horizontal sieve shaker, tap shaker, or rotary tap shaker. One or more sieving aids 480 may be added to the receiving portions 410a, 410b of one or more of the sieves 405a, 405b. The amount of sieving aid 480 and / or the physical parameters of the sieving aids added to each of the receiving portions 410a, 410b may be the same or different. For example, a larger amount and / or a smaller size (diameter) of sieving aid 480 may be provided in the receiving portion 410b of one or more lower sieves 405b than in one or more upper sieves 405a.

[0063] Experimental example The loads were obtained after disassembly and thermal delamination of the PV modules, each containing a fragment of the broken glass layer along with a fragment (chip) of the PV silicon wafer and associated metallization elements.

[0064] One of the loads was sieved using a vibrating sieve shaker (Retsch™ AS200 vibrating sieve shaker). The vibrating sieve shaker utilizes a vertical stack of sieves with decreasing sieve opening sizes (10 mm, 5 mm, 3.15 mm, 1 mm, 0.5 mm, 0.15 mm, and 0.075 mm) located above a pan and vibration mechanism. Sieving was carried out over a single continuous sieving time of 3 minutes at a vertical vibration amplitude of 1.5 mm. No sieving aid was used in the sieving process. The weight separation of the load fractions within each sieve after the sieving process was completed is listed in Table 1 below, along with the estimated silver content of each fraction. It was observed that the fractions on the sieves with the four largest aperture sizes (10 mm, 5 mm, 3.15 mm, and 1 mm) each contained numerous fragments of PV silicon wafers mixed with broken glass, with the sieves with smaller apertures collecting PV silicon wafer powder representing approximately 2.5 wt.% of the original load. [Table 1]

[0065] The load was sieved using a vibrating sieve shaker (Retsch™ AS200 vibrating sieve shaker). The vibrating sieve shaker utilizes an identical vertical stack of sieves with decreasing sieve opening sizes (10 mm, 5 mm, 3.15 mm, 1 mm, 0.5 mm, 0.5 mm, and 0.075 mm) located above the pan and vibration mechanism, except that a sieving aid was added to the four largest opening sizes (10 mm, 5 mm, 3.15 mm, and 1 mm; these were the largest opening sizes observed after the sieving process of the previous example to contain numerous fragments of PV silicon wafers mixed with the broken glass). Sieving was performed using the following parameters: (A) Intermittent 3-second periods of 1.5 mm vertical vibration amplitude separated by periods of no sieving for a total sieving time of 5 minutes, or (B) 5-second periods of 2.0 mm vertical vibration amplitude separated by periods of no sieving for a total sieving time of 5 minutes.

[0066] The amount, diameter, and material of the sieving aid used in each sieve, along with the weight of the portion of the load in each sieve before and after the sieving process, and the estimated separation efficiency of the glass fragments from the PV silicon weber and associated metallized element fragments, are listed below in Tables 2A and 2B, which provide the results when applying the sieving parameters (A) and (B) described above, respectively. [Table 2A] [Table 2B]

[0067] The results show that the use of a sieving aid significantly improved the separation efficiency of the sieving process, with virtually 100% of all PV silicon wafer fragments and associated metallization elements being sufficiently reduced in size by mechanical interaction with the sieve and sieving aid to pass through the 10 mm and 5 mm opening size sieving screens, with only the glass fragments remaining in these sieving sections. Furthermore, using higher vertical vibration amplitudes and applied for longer intermittent periods, similar separation efficiencies were achieved with sieving sections having 3.15 mm and 1 mm opening sizes, resulting in an estimated 98% of the PV silicon wafer fragments being recoverable using this process.

[0068] In a further experimental example, a similar experimental setup was utilized for the load resulting from the thermal stripping process of a PV module. After an initial sieving process without using a sieving aid, the weight of the fraction of the load distributed across the different sieves was determined and is listed in the second column of Table 3 below. A sieving process was then applied to the fraction of the load using the sieving conditions and sieving aids having the parameters (amount, diameter, and material) listed in Table 4 below. After completion of this sieving process, the weight of the fraction of the load distributed across the different sieves was determined and is listed in the third column of Table 3 below. [Table 3] [Table 4]

[0069] By comparing the particle size distributions before and after applying the proposed sieving process using a sieving aid, it can be concluded that most of the large fragments of the PV silicon wafers (approximately 14 g) were originally captured on the 1 mm, 3.15 mm, and 5 mm sieves, and these fragments were crushed by the sieving aid during the sieving process. Figures 7A, 8A, and 9A show the separation performance of the initial sieving process (without a sieving aid) for the 5 mm, 3.15 mm, and 1 mm sieves, respectively. Figures 7B, 8B, and 9B show the separation performance of the sieving process (with a sieving aid) for the 5 mm, 3.15 mm, and 1 mm sieves, respectively. As shown in Figures 7A and 7B, a larger portion of PV silicon wafer 760 fragments remain on the 5 mm sieve after the initial sieving process, with only glass fragments 770 remaining in the receiving portion, compared to the portion of PV silicon wafer fragments remaining after the proposed sieving process. A similar finding is noted when comparing the proportions of PV silicon wafer 860, 960 fragments and glass 870, 970 remaining fragments after the initial sieving process and the proposed sieving process, as shown in Figures 8A-9B. The majority of these fragments (approximately 10.8 g) were concentrated on the 0.5 mm sieve, as shown in Figure 10.

[0070] Silver concentration provides an indicator of separation efficiency, as it is one of the most valuable materials contained in a typical PV silicon wafer-containing load. In this example experiment, approximately 191.2 mg of AgNO3 can be extracted from this target load. Approximately 33% (62 mg) of the silver content is contained within the PV silicon wafer powder, which originally has a particle size of less than 1 mm and can be easily recovered and processed. The lower sieves (e.g., 0.5 mm sieves, 0.075 mm sieves) concentrate approximately 13 g of larger PV silicon wafer fragments, from which approximately 124.5 mg (65%) of AgNO3 can be extracted. After the sieving process, a small portion of the fragmented PV silicon wafers remains on the upper sieve, and approximately 4.7 mg (2%) of AgNO3 can be extracted from these fragments.

[0071] Those skilled in the art will appreciate that numerous variations and / or modifications may be made to the above-described embodiments without departing from the broad general scope of the present disclosure, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. 1. A method for separating materials in a photovoltaic (PV) module, comprising: Providing at least one sieve and at least one collection section, the sieve comprising a receiving section and a sieving screen, the sieving screen including a plurality of openings, and allowing material fragments having a size smaller than the opening size of the plurality of openings to pass from the receiving section through the sieving screen and reach the collection section; introducing a load into the receiving portion, the load including a first load portion and a second load portion, the first load portion including a piece of a first material of the photovoltaic module, the second load portion including a piece of a second material of the photovoltaic module, the second material being a different type of material than the first material; adding one or more sieving aids to said receiving portion; agitating the at least one sieve, wherein the one or more sieving aids mechanically interact with the load to assist in reducing the plurality of pieces of the first material to a size below the aperture size.

2. 2. The method of claim 1, wherein the agitation of the at least one sieve is such that a portion of the first load portion passes from the receiving portion through the sieving screen to the collection portion, the portion of the first load portion being larger in size than any portion of the second load portion that passes from the receiving portion through the sieving screen to the collection portion.

3. 3. The method of claim 1 or 2, wherein the agitation of the at least one sieve is such that a majority of the first load portion passes from the receiving portion through the sieving screen to the collecting portion and a majority of the second load portion remains in the receiving portion.

4. 4. The method of claim 3, wherein the majority of the first load portion comprises at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of the first load portion.

5. 5. The method of claim 3 or 4, wherein the majority of the second load portion comprises at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 98% by weight of the second load portion.

6. 10. The method of any one of the preceding claims, wherein the reduction of the plurality of pieces of the first material to a size below the aperture size is faster than any reduction of the plurality of pieces of the second material to a size below the aperture size.

7. 10. The method of any one of the preceding claims, wherein one or more of the sieving aids have the shape of a ball, sphere, ellipsoid, cube, cuboid, cylinder, cone, or pyramid.

8. 10. The method of any one of the preceding claims, wherein one or more of the sieving aids comprises stainless steel, rubber, plastic, or ceramic.

9. 10. The method of any one of the preceding claims, wherein adding the one or more sieving aids to the receiving portion comprises adding to the receiving portion at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 40, at least 50, at least 60, at least 100, at least 200, at least 500, at least 1000, at least 10,000, 2 to 10,000, 10 to 1,000, 100 to 500, 500 to 1,000, 200 to 800, 2 to 100, 5 to 75, or 10 to 60 sieving aids.

10. 10. The method of any one of the preceding claims, wherein the pieces of the first material are pieces of photovoltaic (PV) silicon wafers of the PV module.

11. The method of claim 10 , wherein the first load portion comprises a metallization element or a fragment of a metallization element of the photovoltaic module attached to or associated with the fragment of the PV silicon wafer.

12. The method of claim 11 , wherein the metallization element comprises one or more of silver, aluminum, tin, copper, zinc, and lead.

13. 10. A method according to any one of the preceding claims, wherein the pieces of the second material are pieces of glass of the PV module.

14. 10. The method of any one of the preceding claims, wherein said agitating said at least one sieve comprises intermittently agitating said sieve.

15. 15. The method of claim 14, wherein intermittently agitating the at least one sieve comprises continuously agitating the sieve during each of a plurality of first time periods, each successive first time period of the plurality of first time periods being separated by a respective second time period, during which the sieve is substantially not agitated.

16. 16. The method of claim 15, wherein during the first period, the sieving aid undergoes a vibrational motion within the receiving portion to mechanically interact with the load.

17. 17. The method of claim 15 or 16, wherein during the second period, the vibrational movement of the sieving aid is interrupted and the sieving aid moves substantially horizontally within the receiving portion.

18. the first period of time is one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes; 18. The method of any one of claims 15 to 17, wherein the second period of time is one of at least 2 seconds, at least 3 seconds, at least 4 seconds, at least 5 seconds, at least 6 seconds, at least 7 seconds, at least 8 seconds, at least 9 seconds, at least 10 seconds, at least 20 seconds, at least 30 seconds, at least 50 seconds, at least 100 seconds, or at least 5 minutes.

19. 20. The method of claim 18, wherein the total stirring period, i.e., the sum of the first period of time, is at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 30 minutes, or at least 1 hour.

20. 20. The method of claim 19, wherein the first period of time is at least 3 seconds, the second period of time is at least 3 seconds, and the total stirring period is at least 5 minutes.

21. 10. The method of any one of the preceding claims, wherein the agitation of the at least one sieve is such that the sieve has an amplitude of vertical movement of at least 1 mm, at least 1.5 mm, at least 2 mm, at least 2.5 mm, at least 3 mm, at least 5 mm, at least 10 mm, at least 20 mm, or at least 50 mm.

22. 10. The method of any one of the preceding claims, comprising providing a plurality of the sieves in a vertically stacked configuration, the receiving portion of at least one lower sieve of the plurality of sieves providing the collection portion for at least one upper sieve of the plurality of sieves located above the at least one lower sieve.

23. 23. The method of claim 22, wherein the sieving screens of the plurality of sieves have decreasing opening sizes from the top to the bottom of the vertically stacked arrangement of the plurality of sieves.

24. 24. The method of claim 22 or 23, wherein one or more sieving aids are added to the receiving portion of two or more of the plurality of sieves.

25. 25. The method of claim 24, wherein the amount of sieving aid and / or the physical parameters of the sieving aid added to each of the receiving portions are different.

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