Mineral wool recycling process

Abstract

The invention relates to a process for recycling waste (1) of mineral wool. According to the invention, the process comprises the following steps: - a step of fragmenting the mineral wool waste in order to obtain smaller particles, - a step of impregnating the particles thus obtained with a binder, - a step of baking the substance (7) consisting of the binder impregnated in the mineral wool particles, - a step of obtaining a solidified final product (30) ready for use in an installation for its insulating and / or mechanical rigidity properties. Figure for the abstract: Fig. 1.

Description

Title of the invention: Mineral wool recycling process

[0001] The present invention relates to a process for recycling mineral wool, such as glass wool.

[0002] Generally, mineral wool waste, which may for example consist of glass wool, is mainly buried in non-hazardous waste storage facilities.

[0003] Currently, recycling solutions for this mineral wool consist of remelting the fibrous materials to create a new raw material for the manufacture of mineral wool. However, these solutions have two main drawbacks: - they require a great deal of energy to remelt the fibers (between 1010° and 1450°C), resulting in significant energy consumption and therefore high costs, - they necessitate the selection of waste materials compatible with these processes, greatly reducing their scope of application.

[0004] A process according to the invention makes it possible to recycle mineral wool while overcoming the disadvantages encountered with existing processes.

[0005] In order to remove any ambiguity, the terms "cooking" and "heating" used in the context of a process according to the invention are equivalent and designate the conditions for setting the binder.

[0006] The invention relates to a process for recycling mineral wool waste.

[0007] According to the invention, the process comprises the following steps: -a step of fragmenting mineral wool waste in order to obtain smaller particles, -a step of impregnating the particles thus obtained with a binder, -a cooking stage of the substance consisting of the binder impregnated in the mineral wool particles, -a step of obtaining a solidified final product ready to be used in an installation for its insulation and / or mechanical rigidity properties.

[0008] Mineral wool waste treated by such a process can come from several sources: deconstruction waste, new mineral wool from new or renovation sites, and production waste from factories. This waste may be with or without a surface layer (e.g., kraft paper, aluminum, bitumen, fiberglass, etc.). The mineral wool waste may, for example, be of the fiberglass or rock wool type. The principle of a process according to the invention is first to reduce the mineral wool waste to the form of particles, and then to impregnate these particles with a binder suitable for hardening. By means of heating, the aim is to obtain a solidified final product consisting of the mineral wool particles and the binder. The final product can, for example, be shaped in a mold used during the heating stage, and / or can, for example, be cut into panels. Advantageously, the final product obtained with such a process possesses thermal insulation properties. Preferably, this product possesses acoustic insulation and / or mechanical rigidity properties, depending on its dimensional and geometric characteristics. Following this process, the final product can either be finished and thus directly used as is in an installation for its insulation and / or mechanical rigidity properties, or be semi-finished, awaiting integration as a component of a finished product.The final product obtained can be used either directly as a wall or ceiling in an installation, or as a supplement to that wall or ceiling to modify its thermal and / or acoustic insulation properties. The binder can take any form, and may, for example, include adhesives; the important thing is that it has properties that allow the particles to bind together.

[0009] According to one possible feature of the invention, the fragmentation step is carried out to obtain particles with a size of 10 cm or less. The advantage of such a step is that it allows for obtaining, before the heating step, a homogeneous substance in which the mineral wool particles are evenly distributed within the binder. The object of a process according to the invention is to obtain a homogeneous final product whose insulation and / or mechanical rigidity properties are constant regardless of the area of ​​the product considered. Advantageously, the particle size is 5 cm or less, and even more advantageously, 2 cm or less.

[0010] According to one possible feature of the invention, the binder used in the mixing step is to be selected from organic binders, such as phenolic resins (formaldehyde-phenol or urea-formaldehyde-phenol), acrylic resins, and polysaccharide-based binders, such as plant-based or bio-based binders. The binder must allow for a homogeneous substance to be obtained with the mineral wool particles before the heating step, and must be capable of hardening after this heating step. The binders listed above are examples of binders particularly suited to a process according to the invention, but are by no means limiting in the context of such a process.

[0011] According to one possible feature of the invention, the impregnation step is carried out using a technique to be selected from dipping, spraying, and injection. These techniques are particularly well-suited to a process according to the invention, but are by no means limiting in the context of such a process.

[0012] According to a possible feature of the invention, during the impregnation step, the binder content by dry mass is less than or equal to 50%. This mass percentage may vary, as it depends on the nature of the binder used and the technical characteristics required for the final product.

[0013] According to one possible feature of the invention, the process includes a step of mixing the binder with the mineral wool particles to obtain a homogeneous resulting product. This step makes it possible to obtain a substance consisting of the binder and the mineral wool particles that is consistent throughout its volume without showing areas deficient in mineral wool particles that could bias the insulating or mechanical properties of the final product obtained. This mixing can be carried out using a mixer, agitator, paddle mixer, or in a mixing tank (rotary drum).

[0014] According to one possible feature of the invention, the heating step is carried out at a variable temperature, corresponding to the curing temperature of the binder used. The objective of this heating step is to obtain a solidified final product. It must therefore be carried out at a heating temperature greater than or equal to the curing temperature of the binder used. The term "variable" means that the heating temperature depends on the nature of the binder used, and not that it varies during this heating step.

[0015] According to one possible feature of the invention, the process includes a compaction step during the heating step to obtain a final product with a density between 40 kg / m³ and 450 kg / m³. Indeed, depending on the requirements of the final product, it may be advantageous to compact this product during or before the heating step in order to obtain the product with the best mechanical and surface finish properties.

[0016] According to one possible feature of the invention, the process includes a step of depositing a surface layer whose composition differs from that of the final product obtained. Preferably, this step of depositing this surface layer is carried out during or after the heating step. This surface layer can be applied to one or more faces of the product obtained. This coating can be of the type: kraft paper, aluminum foil, fiberglass, or any other type of surface coating. This surface layer can also consist of a coating deposited by any type of technique, such as, for example, a spray.

[0017] According to one possible feature of the invention, the process includes a shaping step of the final solidified product obtained, this shaping step comprising at least one step to be selected from cutting, surface grinding to obtain good flatness, and specific machining to obtain a groove. Indeed, the final product obtained with a process according to the invention having a Depending on its intended use and / or specific application, it can be shaped by any means to meet those requirements. The final product can also be packaged in panel form. Shaping the final product allows its structural characteristics to be adapted to the specific need.

[0018] A process according to the invention has the advantage of comprising several simple steps, the judicious chronology of which makes it possible to produce a surprising product, directly reusable in an installation for its insulation and / or mechanical rigidity properties.

[0019] A detailed description of a preferred embodiment of a recycling process according to the invention is given below, with reference to the following figures:

[0020] [Fig. 1] represents a side view of an installation intended to carry out a process according to the invention, said installation comprising apparatus enabling a mineral wool fragmentation step, a binder impregnation step, and a binder mixing step with the mineral wool particles,

[0021] [Fig.2] represents a side view of a framing table intended to receive the a mixture of binder and mineral wool particles,

[0022] [Fig.3] shows a side view of a plating press, a batch oven or a oven, intended to carry out a compaction and heating step of the binder mixture and mineral wool particles for the implementation of a process according to the invention,

[0023] [Fig.4] shows a side view of a cutout for shaping a product final result obtained by means of a process according to the invention,

[0024] [Fig. 5] represents a side view of a pallet for the storage and transport of the product obtained by means of a process according to the invention and already shaped.

[0025] A recycling process according to the invention aims to transform mineral wool waste into finished or semi-finished solid objects suitable for use in installations for their thermal and / or acoustic and / or mechanical insulation properties. The term "finished" means that the product resulting from the recycling process will be packaged so that it can be used directly as such in the installation. The term "semi-finished" means that the product resulting from said process is awaiting integration as a component of a finished product.

[0026] A process according to the invention makes it possible to recycle mineral wool waste, which can come from several sources: deconstruction waste, new mineral wool from new or renovation sites, and production waste from factories. In a process according to the invention, this waste can be with or without a surface layer (for example, kraft paper, aluminum, bitumen, glass veil, etc.). The mineral wool waste can, for example, be glass wool or rock wool.

[0027] The raw materials to be recycled may undergo preliminary treatment such as cleaning, dusting, washing, etc., if their condition so requires. As mentioned above, in the case of the presence of a surface layer (kraft paper, aluminum, etc.) on the mineral wool waste, these surface layers may be removed beforehand in order to obtain a higher quality product with this process.

[0028] A recycling process according to the invention comprises the following steps: A- a fragmentation step

[0029] As illustrated in [Fig. 1], the waste 1 is conveyed in its raw state to a device 2, which may be, for example, a crusher or shredder, which will be used to cut said waste 1 into small fragments, the dimensions of which are less than 10 cm, and advantageously less than 5 cm, and even more advantageously, less than or equal to 2 cm. Before being cut into small fragments, the waste 1 may have undergone a preliminary decompaction step. B - a step of impregnating a binder

[0030] Referring to [Fig. 1], the small fragments are discharged from the cutting apparatus 2 by means of a conduit 3 connecting said apparatus 2 to a mixer 4. A binder reservoir 5 is in fluidic communication with the conduit 3, so as to allow the small fragments circulating in said conduit 3 to be impregnated with said binder before reaching the mixer 4. The binder can be made of a multitude of materials, and can therefore, for example, consist of organic binders (phenolic resins (formaldehyde-phenol or urea-formaldehyde-phenol)), acrylic resins, or polysaccharide-based binders (plant-based, bio-based binder). This concept of binder encompasses the concept of adhesive. Various methods can be used to carry out this impregnation, such as dipping, injection, spraying, or any other process.In the case of spraying, the binder will be sprayed in liquid form onto the fragmented mineral wool elements.

[0031] The binder content by dry mass, relative to the mineral wool waste 1 to be treated, depends on the technical characteristics of the binder and the performance level expected for the finished or semi-finished product. It may vary from a few percent to 50%. C - a homogenization step.

[0032] The substance, consisting of the small fragments and the binder, exits the conduit 3 by means of a nozzle 6 before reaching the mixer 4, where it is mixed to obtain a continuous and homogeneous material in which the fragments are evenly distributed. This mixer 4 encompasses a multitude of devices, such as those involving rotating drums, or tanks including a mixing device like paddle mixers.

[0033] The mineral wool waste fragmentation step 1 aims to obtain elements small enough to be thoroughly impregnated with binder. Referring to [Fig. 2], once the substance 7, consisting of the binder and the small fragments, has been sufficiently mixed in the mixer 4, it is collected on a framing table 8 or a conveyor belt in the case of a continuous flow process. D - A heating step

[0034] The framing table 8, loaded with substance 7, is conveyed to a heating unit 9 where it is baked. The substance 7 is unloaded from the framing table 8 and then placed in said unit 9. This baking step can be carried out by any type of process that allows the temperature and curing time of the binder to be reached, which will depend on its technical characteristics. The machines used for this baking step can be of the heated plate type or ovens, and the heating technique can, for example, be steaming. Any other heating process may also be suitable. The baking can be continuous in a tunnel oven or statically by batch. E - a forming step

[0035] Referring to [Fig. 3], once the homogeneous substance 7, consisting of the binder and small fragments, has been placed in the firing apparatus, it can be simultaneously pressed, for example, by bringing two plates 20, 21 together, to obtain different product densities or specific shapes in molds. The densities of the fired products can, for example, vary from 40 kg / m³ to 450 kg / m³. In the case of pressing specific shapes, it can be possible to produce, for example, semi-spherical shells or studded pallets, or any other shape. F - a surfacing step

[0036] During the cooking stage, a surface layer may be applied to one or more faces of the products. This surface layer, which can be considered a coating, may, for example, be made of: kraft paper, aluminum foil, fiberglass, or any other type of surface coating. G- a marking step

[0037] The product may also be marked, either by printing or by burning, for example using a laser. The purpose of this marking is to identify the product obtained by a process according to the invention by means of information including, for example, the date of manufacture, the place of manufacture, the components of the product, the origin of the product, etc. H - A cutting and / or rectification step

[0038] With reference to [Fig.4], the solid product resulting from the cooking stage can be cut to the dimensions required for its use, as a finished or semi-finished product. by means of equipment 10 involving a saw 11 or any other cutting system such as a guillotine. It can then take, for example, the form of panels of varying sizes. It can also be rectified on one or more of its sides to achieve a sufficient level of flatness necessary for its use as a finished or semi-finished product. The product can also be subjected to specific cuts, such as grooves or holes, to enable its future use. I - A palletizing stage

[0039] With reference to [Fig.5], once the final product from the recycling process according to the invention has been manufactured in its final form, for example in the form of panels, they are stacked on a base 12 and then packaged individually or in several units before being delivered to a customer.

Claims

Demands

1. A process for recycling mineral wool, characterized in that it comprises the following steps: - a shredding step using a shredder to obtain smaller particles, the particle dimensions being less than or equal to 10 cm, - an impregnation step of the particles thus obtained with a binder, the binder being chosen from organic binders, acrylic resins, and polysaccharide-based binders, the binder content by dry mass being less than or equal to 50%, - a baking step of the substance (7) consisting of the binder impregnated in the mineral wool particles, the baking step comprising a compaction step to obtain a final product having a density between 40 kg / m³ and 450 kg / m³, - a step of depositing a surface layer having a composition different from that of the final product obtained.-a step of obtaining a solidified final product (30) ready to be used in an installation for its insulation and / or mechanical rigidity properties.

2. Recycling process according to claim 1, characterized in that the impregnation step is carried out using a technique to be selected from dipping, spraying, and injection.

3. Recycling process according to claim 1 or 2, characterized in that it comprises a step of mixing the binder with the mineral wool particles in order to obtain a homogeneous resulting product.

4. Recycling process according to any one of claims 1 to 3, characterized in that the step of solidifying the bonds between particles by baking is carried out with a temperature corresponding to the hardening temperature of the binder used.

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