Method for classifying and recycling refractory shaped products, preferably bricks, and use thereof

Abstract

The invention relates to a classification method and to a method for recovering preferably structured ceramics, refractory materials, shaped products (1; 1a; 1b), preferably a slab, and the use of the classified or recycled product.

Description

[0001] The invention relates to a method for sorting and a method for recycling, preferably stoneware, refractory materials, shaped products, preferably bricks, and the use of the sorted or recycled products.

[0002] In the context of the present invention, the term "refractory material" is not limited to the definition according to ISO 836 or DIN 51060, which defines a high temperature cone equivalent of > 1500° C. Refractory products in the sense of the present invention include those with a compression softening point T according to DIN EN ISO 1893:2008-09. 0.5 , T 0.5 ≥600℃, preferably T 0.5 ≥800°C. Therefore, the refractory or refractory granular material or particle material in the present invention is suitable for having the above compression softening point T 0.5 The material or granular material of the refractory product.

[0003] Refractory products are used to protect aggregate structures in aggregates at temperatures between 600 and 2000°C, especially between 800 and 1800°C.

[0004] In particular, they are used for refractory cladding (lining) of heat treatment equipment, preferably smelting, firing and heat treatment equipment or transport containers. However, they can also be functional products (see "Gerald Routschka / Hartmut Wuthnow, "Feuerfeste Werkstoffe" Practice Manual, 6th Edition, Vulkan-Verlag (hereinafter referred to as "Practice Manual"), Chapter 1.6).

[0005] Refractory lining of equipment or transport containers, which lines the outer shell of the equipment or transport container and can be single-layer or multi-layer, usually multi-layer. The lining consists of a working sleeve or a wear sleeve, which is located on the fire side or inside the aggregate, which wears out during use and must be replaced regularly. If the wear sleeves consist of refractory bricks, especially their fire side will wear out during use. However, at least a part of the bricks can be reused after use and can be mechanically removed from the wear sleeve for this purpose.

[0006] Additionally, the lining may include a permanent casing that follows the wear casing. The permanent casing then stays in the equipment or shipping container for several furnace runs or cycles and serves as a safety enclosure. An insulating backing may also be added behind the permanent enclosure.

[0007] Known coarse ceramic products are products made of granular materials with a particle size of up to 6 mm and in special cases up to 25 mm (Practical Manual, Chapter 2). Coarse ceramics are distinguished from fine ceramics by the particle size of the microstructural components. If the microstructural components are at least partially larger than 1 mm, the product is a coarse ceramic product; if the microstructural components are all ≤ 1 mm, it is a fine ceramic product.

[0008] Furthermore, among refractory products, a distinction is made between non-basic (Handbook of Practice, 4.1) and basic products (Handbook of Practice, 4.2). According to DIN EN ISO 10081:2005-05, a distinction is made between non-basic and basic refractory products, in particular on the basis of chemical reaction behavior. The product group of non-basic products includes materials from the SiO2-Al2O3 series and other materials that cannot be classified more precisely based on their chemical reaction behavior, such as SiC and carbon products. An essential feature of most basic products is that the sum of the oxides MgO and CaO predominates. In addition, chromite, picrochrome, spinel and forsterite bricks are classified as basic products, although they are almost neutral.

[0009] For stoneware products, a distinction is also made between formed and unformed products.

[0010] Shaped stoneware products are unfired, possibly tempered or ceramic fired products, preferably produced in a ceramics factory, in particular bricks or slabs. They have a defined geometry and are ready for installation. The shaping is carried out, for example, by pressing, stamping, punching or slip casting. The shaped products, in particular bricks, are laid up into walls with or without mortar ("chipping"), for example to form linings. The production process of stoneware shaped products is usually divided into the following steps (Practical Manual, page 14 / point 2.1):

[0011] -Prepare

[0012] -mix

[0013] -forming

[0014] - Dry (if necessary)

[0015] - (if necessary) heat treatment to 800°C or firing

[0016] - Post-processing (if necessary)

[0017] Unformed products (Practical Handbook, p. 142 / point 5) are products that are usually formed into their final shape at the user's site from fresh unformed blocks or blocks (e.g. by casting, vibrating, poking, punching or spraying). Unformed products are usually placed behind formwork in a larger area at the place of use and, after hardening, form part of the lining. Unformed products are, for example, sprayed blocks, punched blocks, cast blocks, vibrated blocks or grouted blocks.

[0018] The recycling of refractory products is becoming increasingly important for economic and ecological reasons and due to resource scarcity. Reusing recycled materials (recyclate) to produce new refractory products has the advantages of cheaper raw materials, lower processing costs, lower energy consumption and lower CO2 emissions compared to virgin raw materials.

[0019] However, to reuse the separated products, they must be sorted by type. This is because different types of products are often mixed after liner separation. Depending on where and when they were used, the products are also subject to different pressures and may have undergone chemical / mineral changes, so not all products are suitable for reuse or for making different products. The separated products may be contaminated, for example, by penetration and / or adhesion by slag, molten clinker, metals, salts or other process media.

[0020] In order to separate the separated products according to their chemical / mineral composition, it is well known in the art to chemically analyze the products using laser induced breakdown spectroscopy (LIBS) (see for example https: / / cordis.europa.eu / article / id / 197342 -how-to-turn-refractory-waste-back-in-to-raw-materials / de). By means of multi-element analysis, different refractory materials can be classified. In particular, the main components and some aggregates can be determined.

[0021] However, it is not always possible to fully characterize refractory products chemically / mineralogically using this method. For example, it is not possible to clearly determine whether a refractory product contains carbon. This is because the surface of refractory products changes during use. The carbon burns off on the fire side of the product. Since the penetration depth of LIBS measurements is usually limited to a few hundred micrometers, carbon may not be detected even if the product contains it.

[0022] Furthermore, it is known in the art to provide refractory products with sensors or chips for various purposes.

[0023] For example, WO2008 / 135135A2 discloses a ceramic component comprising an integrated sensor for data acquisition and transmission, the information acquired being the identification of the component, the physical properties of the component, the movement of the component, the usage time of the component or the location of the component. The task is to be able to identify and state the condition or working time of the component before, during and after use. The information used to identify the component includes, for example, product type, material type, manufacturer details, manufacturing date, delivery date and usage date. Specifically, for example, temperature measurements and mechanical stress measurements as a function of time are used to predict the wear condition of the component so that the component can be replaced in time, but not too early. WO2008 / 135135A2 does not involve the recycling of components.

[0024] WO2020 / 254134A1 also relates to the use of sensors (e.g. RFID chips) in refractory components (e.g. sliding gate valve plates). This relates to the monitoring and tracking of replaceable refractory components in metallurgical plants.

[0025] EP 3 119 915 B1 discloses a metallurgical container with a wirelessly readable transponder.

[0026] WO2010 / 057656A1 relates to a device for actively tracking specific data related to a system of a metallurgical plant or its components, wherein at least one writable and readable storage medium for specific data (e.g. an RFID chip) is permanently connected to each component and the specific data can be changed periodically and / or in response to input. The data includes physical and / or mechanical and / or chemical properties of the component, etc.

[0027] The object of the present invention is to provide a sorting method for sorting preferably coarse ceramics, refractory materials, shaped products (preferably bricks), which are preferably used in aggregates (preferably furnaces) and separated therefrom after use, thereby ensuring efficient and accurate sorting of the separated products.

[0028] It is a further object of the present invention to provide a method for recovering the separated product and to provide uses of the separated product.

[0029] This problem is solved by a sorting method having the features of claim 1, a recycling method having the features of claim 13 and a use having the features of claim 14. Advantageous further embodiments of the invention are characterized in the following dependent claims.

[0030] The invention will be explained in more detail below with reference to the accompanying drawings. It shows:

[0031] Figure 1 : Schematic diagram of the life cycle of the recycled refractory fired product according to the present invention;

[0032] Figure 2 : Schematic diagram of the life cycle of a recycled refractory unfired product according to the present invention;

[0033] Figure 3 : Schematic cross-section of a refractory brick with an integrated transponder.

[0034] Figure 1 The life cycle 100 of a refractory shaped fired product 1 is schematically shown.

[0035] Thus, firstly, the raw materials for production are processed 101 in a known manner. These raw materials include primary raw materials and secondary raw materials. Afterwards, the processed raw materials are mixed 102 and shaped 103, preferably pressed 104, to form a shaped green product 1a. The shaped, in particular pressed green product 1a is then ceramic fired 105 in a furnace.

[0036] According to the invention, after firing, the fired product 1 is provided or equipped 106 with at least one transponder 2. Thereafter, the fired product 1 is preferably subjected to a quality control 107.

[0037] The transponder 2 is known as a radio communication device that receives incoming signals and automatically responds or forwards them. As is known, the transponder 2 can receive information from and / or send information to a transmitter and / or receiver unit 8 in a contactless process.

[0038] The transponder 2 comprises a coupling element (e.g. an antenna) and a microchip in a manner known per se. The microchip comprises analog circuits (transceiver) for receiving and sending as well as digital circuits (preferably a microcontroller) and a memory. The memory is a memory that can be written to at least once. The memory contains the unchangeable, in particular unique identity of the transponder 2. Preferably, however, it is a rewritable memory so that information can be stored and / or changed again and again during the service life of the transponder 2.

[0039] The transponder 2 is preferably a passive transponder 2 .

[0040] As is known, a passive transponder 2 obtains the energy required for communication and for carrying out internal processes only from the electromagnetic field of the transmitter and / or receiver unit 8 .

[0041] Preferably, the transponder 2 is also an RFID (Radio Frequency Identification) transponder 2 .

[0042] Furthermore, the transponder 2 preferably comprises a device for measuring the temperature and / or a device for measuring the humidity.

[0043] Furthermore, the unfired and fired product 1; 1a comprises a product fire side or product hot side 3a and a product cold side 3b opposite thereto. When the product 1 is installed, the product hot side 3a faces the burning aggregate interior of the aggregate 5 or the combustion chamber 4, preferably the furnace 6. The product cold side 3b faces away from the combustion chamber 4.

[0044] Preferably, the transponder 2 is arranged or positioned or fixed in a cutout or groove 7 in the product cold side 3b of the product 1. The arrangement on the product cold side 3b ensures that the temperature load on the transponder 2 during use is as low as possible. The arrangement of the transponder 2 in the groove 7 also ensures mechanical protection of the transponder 2. In particular, it is ensured that the transponder 2 is not damaged during handling of the product 1 during transport and during mounting and dismounting of the product 1.

[0045] According to the invention, product-specific information is now applied 108 to the transponder 2 by means of a transmitter / receiver unit 8 known per se, whereby at least information about the chemical and / or mineral composition of the respective product 1 is applied or stored. Preferably, the product-specific information is a recipe. The recipe contains all materials used to manufacture the product, i.e. in particular the main and minor ingredients used, in particular additives. Preferably, the recipe also contains information about the chemical composition of the materials used, in particular the impurity content, for example the iron content. In particular, the presence and amount of additives cannot be easily determined using known methods.

[0046] In addition, at least one of the following information is preferably applied or stored:

[0047] - Date of production

[0048] -Internal recipe number

[0049] - Manufacturing process information, in particular mixing time, and / or pressing pressure, and / or firing temperature

[0050] -Scrap code number

[0051] - Pallet number for tracking

[0052] For example, using the production date in combination with the recipe number, it is also possible to determine the materials used for production and their composition if the relevant data is stored in a database. It is then not necessary to store the complete recipe on the transponder 2.

[0053] After application 108 of the information, the fired product 1 is packaged 109 and transported 110 to the point of use.

[0054] After reaching the place of use, further information can be applied 108 to the transponder 2 and / or information can be read out 111 .

[0055] In particular, the read-out information can be taken over by the plant operator's goods management system.

[0056] Afterwards, the product 1 is installed or installed 112 into the aggregate 5. In particular, the aggregate 5 is refractory lined or coated 113 with the refractory product 1. The refractory product 1 is preferably used for producing a wear-resistant or permanent casing or an insulating backing. Thus, after installation 112, they form part of the lining 9 of the aggregate 5, in particular a wear-resistant or permanent casing or an insulating backing.

[0057] Before or after installation 112, preferably further information is applied 108 to the transponder 2, in particular information about the place of use (in particular the aggregate 5 itself) and preferably the area in the aggregate 5 (preferably in the furnace 6), and / or the assembly method. Regarding the assembly method, in particular information about whether the product 1 is bonded together with mortar can be applied.

[0058] Thereafter, the product 1 is used 114 in an aggregate 5 , preferably in a furnace 6 .

[0059] If a transponder 2 is provided for this purpose, preferably continuous temperature measurements and / or humidity measurements and / or atmospheric measurements are preferably carried out during use (ie in situ) by the respective transponder 2. The transponder 2 also stores these measurement results.

[0060] After a period of use, the product 1 is decomposed or separated 115 from the assembly 5, preferably from the furnace 6.

[0061] Preferably, after separation 115, further information is applied 108 to the transponder 2 of the separated product 1b, in particular information related to the use 114 of the product 1, preferably information about the usage time and / or the temperature conditions inside the aggregate or in the combustion chamber 4 and / or the atmosphere inside the aggregate or in the combustion chamber 4, in particular the alkali content in the atmosphere and / or in the aggregate 5, preferably the material produced or processed in the furnace 6, and / or the raw materials used for this purpose.

[0062] This is because, if the product 1 is subjected to stress and changes during use, the mineralogical and / or chemical composition of the separated product 1b can also be predicted from the information about the use of the product 1.

[0063] The separated product 1b is then sorted 116. According to the invention, the sorting 116 is carried out based in particular on information about the mineralogical and / or chemical composition of the product 1b contained on the transponder 2. To this end, the information is read 111 from the transponder 2 before the sorting 116.

[0064] The read information is processed by a data processing program or a data processing system and / or an operator and used for classification.

[0065] Specifically, the product 1 b is sorted into different material parts during sorting 116. Depending on whether the material parts are reusable, the product 1 b can be returned 117 and reused, or disposed of 118 in accordance with the law.

[0066] For reuse, the reusable product 1 b is again provided to the manufacturing process to produce a new refractory product 1 , in particular a reprocessed product.

[0067] The reusable products 1b can be used to manufacture products 1 or other refractory products of the same product type. For example, they can also be used to manufacture unformed refractory products (not shown).

[0068] Figure 2 The life cycle 100a of an unfired shaped refractory product 1a is shown.

[0069] In contrast to the fired product 1, preferably only a heat treatment 119 up to 800°C is carried out instead of the firing 105. The unfired product 1a is then fired in situ during use 114 in a manner known per se.

[0070] Especially for unfired products 1a, information on use facilitates classification, since these products usually undergo chemical and / or mineralogical changes during use.

[0071] Furthermore, according to the invention, fired or unfired products 1; 1a which are not used in aggregate 5 but are nevertheless to be recycled are also sorted.

[0072] In particular, products 1; 1a must be recycled if they have exceeded their useful life or have changed for other reasons during storage or transport, such that they can no longer be used, i.e. are unusable. For example, magnesia bricks may be exposed to high humidity for a long time during storage or transport, causing them to hydrate and making them unusable.

[0073] This can be determined by reading the transponder 2 (if the transponder has means for measuring humidity).

[0074] Furthermore, waste materials generated during the manufacture of the product 1; 1a or the product 1; 1a generated due to overproduction must be recycled.

[0075] Since the sorting 116 is based on the information contained on the transponder 2 or read out therefrom, the method according to the invention ensures sorting by type 116, i.e. efficient and reliable sorting 116. Error-prone and time-consuming laser optical determination of the chemical and / or mineralogical composition of the products 1; 1a; 1b and / or manual sorting are not necessary. A finer or more detailed sorting 116 is also possible. This is because the transponder 2 can contain not only information about the main components, but also about secondary components, for example, also about binders and additives, so that sorting can also be carried out based on this. This means that the quality of the recyclate can be further improved.

[0076] According to the method of the invention, the products 1; 1a; 1b can be classified not only according to the chemical and / or mineralogical composition, but also, for example, according to the origin of the raw materials and / or the influence of the use on the products.

[0077] Unlike barcodes, transponders 2, preferably RFID transponders, can be read even if optical methods cannot be used. In addition, as described, information from a continuous process can be recorded and output in several steps. Preferably, data is even recorded on-site as explained, which can be used for classification 116.

[0078] Of course, within the scope of the invention, the transponder 2 already contains information, in particular product specific information, before being attached to the refractory product 1; 1a. The information can also be applied to the transponder 2 before the quality control 107. It is important that the information is present on the transponder 2 before the installation 112 of the product 1; 1a.

[0079] It is also possible that the transponder 2 only contains a tag for uniquely identifying the product 1; 1a, without any other product-specific information. The classification criteria used for the classification cannot then be read directly.

[0080] The label is then assigned to the product property, in particular the recipe, by data processing only after reading the transponder 2. In this case, for example, all necessary product-specific information, in particular the recipe, of the respective product 1; 1a is stored in a database.

[0081] This also applies to all other information. In principle, the classification criteria used for classification do not have to be read directly from the transponder 2. Instead, the information can be stored on the transponder 2, which is then read out and the classification criteria and any other information assigned to it are stored in a database. As mentioned above, the information stored on the transponder 2 can be a recipe number or other information for uniquely identifying the product 1; 1a.

[0082] In this case, the transponder 2 can also be a simpler transponder 2 which has only a microprocessor without a rewritable memory or a SAW (surface acoustic waves) transponder.

[0083] Finally, it should be pointed out that all of the above-mentioned, in particular claimed, features of the sorting method and / or recycling method are particularly advantageous per se and in any combination and are the subject matter of the present invention.

[0084] In particular, all of the above-mentioned information read from the transponder and / or all of the information for processing the information read from the transponder can be combined with one another in any combination.

Claims

1. A classification method for classifying (116), preferably stoneware, refractory materials, shaped products (1; 1a; 1b), preferably bricks, wherein: The products (1; 1a; 1b) are classified at least on the basis of their mineral and / or chemical composition, The characteristic is that The product (1; 1a; 1b) comprises a transponder (2) which is read out for classification, and the product (1; 1a; 1b) is classified at least on the basis of its mineralogical and / or chemical composition based on or by processing the read out information.

2. The classification method according to claim 1, It is characterized in that The classification criteria for classifying the product (1; 1a; 1b) are read directly from the transponder (2) and / or are determined by data processing the information read from the transponder (2).

3. The classification method according to claim 1 or 2, It is characterized in that The transponder (2) contains information about the mineralogical and / or chemical composition of the product (1; 1a; 1b) and classifies the product (1; 1a; 1b) at least based on the information.

4. The classification method according to claim 1 or 2, It is characterized in that The information read from the transponder (2) and / or the information used for processing the information read from the transponder (2) is one or more of the following: -formula, - Date of manufacture, - internal recipe number, - information on the manufacturing process of the product (1; 1a), in particular, the mixing time, and / or the pressing pressure, and / or the firing temperature, - Waste code number - the place of use of the product (1; 1a), - the duration of use of the product (1; 1a), - the temperature conditions inside the equipment (4) for aggregates (5), preferably a furnace (6), in which said product (1; 1a) is used, - the atmosphere inside the device (4) for aggregates (5), preferably the furnace (6), in which the product (1; 1a) is used, in particular the alkali content of the atmosphere, -Pallet number.

5. The classification method according to claim 1, It is characterized in that The product (1; 1a; 1b) comprises an RFID transponder as a transponder (2).

6. The classification method according to claim 1, It is characterized in that The product (1; 1a; 1b) comprises a passive transponder (2).

7. The classification method according to claim 1, It is characterized in that The transponder (2) comprises means for temperature measurement, and / or means for humidity measurement, and / or means for atmosphere measurement.

8. The classification method according to claim 1, It is characterized in that The product (1; 1a; 1b) is a product (1b) which is at least partially used in an aggregate (5), preferably a furnace (6) or a transport container and is removed therefrom after use.

9. The classification method according to claim 8, It is characterized in that The transponders (2) are each arranged in a recess (7) in the product cold side (3b) of the removed product (1b).

10. The classification method according to claim 8 or 9, It is characterized in that The removed product (1b) is a refractory lining product (1b) and / or a functional product.

11. The classification method according to claim 1, It is characterized in that The product is an at least partially unusable product (1; 1a), in particular a waste product (1; 1a), a hydrate change that occurs in a product (1; 1a) that has changed (preferably hydrated) during the manufacturing process, and / or during storage, and / or transportation.

12. The classification method according to claim 1, It is characterized in that Some of the products (1; 1a) are overproduced products (1; 1a).

13. A method for recovering coarse ceramic refractory shaped products (1; 1a), preferably bricks, used in aggregates (5), preferably in furnaces (6) or transport containers, comprising the following steps: a) separating said product (1; 1a) from said aggregate (5), preferably from a furnace (6), b) classifying said separated products (1b) at least based on their mineralogical and / or chemical composition, c) preferably further processing the classified product (1b), The separated products (1b) comprise a transponder (2) and are sorted according to the sorting method of one of the preceding claims.

14. Reuse of the product (1; 1a; 1b) sorted according to the sorting method according to any one of claims 1 to 12 or the product (1b) recovered according to the method according to claim 13, preferably for the production of coarse ceramic, refractory, shaped or non-shaped products.

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