Method and equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors

Abstract

This invention provides a separation and recovery method that enables the efficient separation and recovery of valuable elements from waste multilayer ceramic capacitors with a high recovery rate using a relatively simple process. [Solution] The method includes a grinding step (A) for grinding waste multilayer ceramic capacitors, a chloride volatilization step (B) for volatilizing and separating metal elements contained in waste multilayer ceramic capacitors as chlorides by reacting the waste multilayer ceramic capacitors with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, either after or before the grinding step, and a chloride recovery step (C) for recovering the chlorides of metal elements volatilized and separated in the chloride volatilization step.

Description

[Technical Field]

[0001] This invention relates to a separation and recovery method and equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors. [Background technology]

[0002] Multilayer ceramic capacitors (hereinafter referred to as "MLCCs" for convenience of explanation) are used in various electronic devices. MLCCs have a structure in which dielectrics and internal electrodes are alternately stacked and sintered together. Generally, barium titanate (BaTiO3) is used as the dielectric, and nickel (Ni) is used as the internal electrode. In addition, the external electrodes (end electrodes) generally contain Sn, Cu, and Ni. The metallic elements such as Ni, Cu, and Sn used in MLCCs are of very high purity, and it is desirable to be able to separate and recover these metallic elements from waste MLCCs (discarded MLCCs) as this would allow for the effective use of resources. Therefore, there is a need for technology that can efficiently separate and recover metallic elements such as Ni, Cu, and Sn (especially Ni) from waste MLCCs with a high recovery rate.

[0003] Patent documents 1 and 2 propose a technique for separating and recovering Ni from MLCC scrap using a wet processing method. The wet treatment method described in Patent Document 1 involves leaching Ni from crushed MLCC scrap with sulfuric acid, neutralizing the resulting leached solution to a pH range of 1 to 5, and precipitating and separating the dissolved binder. After precipitating and separating this binder, the leached solution is neutralized to a pH range of 6 to 9 to precipitate Ni, and after separating the leached solution containing the remaining binder, the resulting precipitate is dissolved again in sulfuric acid to obtain a nickel solution. Furthermore, the wet treatment method described in Patent Document 2 involves leaching MLCC scrap with a mineral acid such as sulfuric acid, neutralizing impurities other than nickel contained in the resulting nickel leachate in the presence of Fe ions, and then removing the impurities by solvent extraction to recover it as a high-purity nickel aqueous solution. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-268459 [Patent Document 2] Japanese Patent Publication No. 2003-277846 [Patent Document 3] Japanese Patent Publication No. 2011-74408 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the methods described in Patent Documents 1 and 2 involve complex processing steps, and since the resulting nickel compound is nickel sulfate, further complex processing is required to obtain anhydrous nickel chloride, which is the raw material for Ni fine powder. In addition, the method described in Patent Document 2 uses solvent extraction, which further complicates the process. On the other hand, Patent Document 3 describes a method for separating rare metal elements such as La and Gd contained in raw materials (mainly optical glass) using the chlorine volatilization method, but it does not consider separating and recovering valuable metals such as Ni from waste MLCCs. Patent Document 3 targets raw materials with relatively homogeneous composition and structure, such as optical glass, whereas MLCCs have a special structure in which the dielectric and internal electrodes (Ni) are firmly solidified by sintering, and Patent Document 3 does not consider raw materials (waste MLCCs) with such a special structure. Furthermore, no other technology for separating and recovering valuable elements such as Ni from waste MLCCs using the chlorine volatilization method is known.

[0006] Therefore, the object of the present invention is to solve the problems of the prior art described above and to provide a separation and recovery method and equipment that can efficiently separate and recover valuable elements from waste MLCCs with a high recovery rate using a relatively simple process. [Means for solving the problem]

[0007] The inventors focused on the chloride volatilization method as a method for separating and recovering valuable elements from waste MLCCs, as it is a simple process and allows for the recovery of metallic elements as solid chlorides. They conducted research on how to efficiently separate and recover valuable elements from waste MLCCs with a high recovery rate using this chloride volatilization method, and as a result, obtained the following findings. (i) When waste MLCCs are subjected to chlorine volatilization treatment without being crushed, it is possible to recover Ni, Cu, and Sn from the external electrodes by volatilization separation. However, it is difficult to recover Ni from the internal electrodes, which are firmly sintered and integrated with the dielectric, by volatilization separation. (ii) By pre-grinding the waste MLCC and then subjecting it to chlorine volatilization treatment, the recovery rate of Ni from the internal electrodes can be significantly improved, however there is a certain limit to how much the Ni recovery rate can be increased. This is thought to be because Sn from the external electrodes inhibits (interferes with) the improvement of the Ni recovery rate.

[0008] (iii) To address the problem in (ii) above, by first volatilizing the waste MLCC by chlorine volatilization treatment without crushing it to volatilize and separate the metal elements (mainly Sn and Cu) of the external electrode, then crushing the waste MLCC, and then volatilizing it again by chlorine volatilization treatment to volatilize and separate the Ni of the internal electrode, the inhibitory effect of Sn on the volatilization separation of Ni is eliminated, so that the Ni of the internal electrode can be efficiently separated and recovered with a high recovery rate. (iv) In particular, by optimizing the treatment temperature and treatment time in the chlorine volatilization treatment, Ni, Cu, and Sn, which are the main valuable metals contained in waste MLCCs, can be efficiently separated and recovered with a particularly high recovery rate.

[0009] This invention is based on the above findings and is summarized as follows. [1] A crushing process for crushing waste multilayer ceramic capacitors, After the pulverization step or before and after the pulverization step, the waste multilayer ceramic capacitor is reacted with chlorine gas in a heating atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, so as to volatilize and separate the metal elements contained in the waste multilayer ceramic capacitor as chlorides. A chlorination volatilization step for performing the treatment; A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized by having a chloride recovery step for recovering the chlorides of the metal elements volatilized and separated in the chlorination volatilization step.

[0010] [2] A pulverization step for pulverizing the waste multilayer ceramic capacitor; The waste multilayer ceramic capacitor after the pulverization step is reacted with chlorine gas in a heating atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, so as to volatilize and separate Sn, Cu, and Ni contained in the waste multilayer ceramic capacitor as chlorides. A chlorination volatilization step for performing the treatment; A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized by having a chloride recovery step for separately recovering the chlorides of Sn and Cu or recovering both chlorides together among the chlorides of Sn, Cu, and Ni volatilized and separated in the chlorination volatilization step, and separately recovering the chloride of Ni.

[0011] [3] In the separation and recovery method of [2] above, in the chlorination volatilization step, Sn is volatilized and separated as a chloride by performing a treatment at a temperature of 250 °C or higher and 350 °C or lower for 0.5 to 5 hours, and then Cu is volatilized and separated as a chloride by performing a treatment at a temperature of 450 °C or higher and 550 °C or lower for 0.5 to 5 hours, and then Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 900 °C or higher and 1050 °C or lower for 0.5 to 5 hours. A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized in that in the chloride recovery step, the chlorides of Sn, Cu, and Ni volatilized and separated in the chlorination volatilization step are separately recovered.

[0012] [4] In the separation and recovery method described in [2] above, in the chlorination volatilization step, Sn and Cu are volatilized and separated as chlorides by performing a treatment at a temperature of 450°C or higher and 550°C or lower for 0.5 to 5 hours, and subsequently, Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 900°C or higher and 1050°C or lower for 0.5 to 5 hours. In the chloride recovery step, among the chlorides of Sn, Cu, and Ni volatilized and separated in the chlorination volatilization step, the chlorides of Sn and Cu are recovered together, and the chloride of Ni is recovered individually. A method for separating and recovering valuable elements from waste multilayer ceramic capacitors is characterized by this.

[0013] [5] Without pulverizing the waste multilayer ceramic capacitor, by reacting with chlorine gas in a heating atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, a first chlorination volatilization step is performed to volatilize and separate Sn and Cu contained in the external electrodes of the waste multilayer ceramic capacitor as chlorides. A pulverization step of pulverizing the waste multilayer ceramic capacitor that has undergone the first chlorination volatilization step. The waste multilayer ceramic capacitor that has undergone the pulverization step is reacted with chlorine gas in a heating atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby performing a second chlorination volatilization step to volatilize and separate Ni contained in the waste multilayer ceramic capacitor as a chloride. A first chloride recovery step of individually recovering the chlorides of Sn and Cu volatilized and separated in the first chlorination volatilization step or recovering both chlorides together. A method for separating and recovering valuable elements from waste multilayer ceramic capacitors, characterized by having a second chloride recovery step of individually recovering the chloride of Ni volatilized and separated in the second chlorination volatilization step.

[0014] [6] In the separation and recovery method described in [5] above, in the first chlorination volatilization step, Sn is volatilized and separated as a chloride by performing a treatment at a temperature of 250°C or higher and 350°C or lower for 0.5 to 5 hours, and subsequently, Cu is volatilized and separated as a chloride by performing a treatment at a temperature of 450°C or higher and 550°C or lower for 0.5 to 5 hours. In the second chloride volatilization step, Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 800°C to 1050°C for 0.5 to 3 hours. A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized in that the first chloride recovery step separately recovers the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization step.

[0015] [7] In the separation and recovery method described in [5] above, in the first chloride volatilization step, Sn and Cu are separated by volatilization as chlorides by performing treatment at a temperature of 450°C to 550°C for 0.5 to 5 hours. In the second chloride volatilization step, Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 800°C to 1050°C for 0.5 to 3 hours. A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized in that the first chloride recovery step recovers together the Sn chloride and Cu chloride that were volatilized and separated in the first chloride volatilization step. [8] A method for separating and recovering valuable elements from waste multilayer ceramic capacitors, characterized in that, in any of the separation and recovery methods described in [1] to [7] above, the chloride recovery step involves cooling the chloride of the metal element and recovering it as a solid chloride.

[0016] [9] A crushing apparatus for crushing waste multilayer ceramic capacitors, A chlorine volatilization furnace is used to perform a volatilization treatment on waste multilayer ceramic capacitors that have been pulverized by the pulverizing device, or waste multilayer ceramic capacitors before and after pulverization by the pulverizing device, by reacting them with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Sn, Cu, and Ni contained in the waste multilayer ceramic capacitors as chlorides. A system for separating and recovering valuable elements from waste multilayer ceramic capacitors, characterized by having a chloride recovery facility that recovers Sn chloride and Cu chloride individually, or both chlorides together, from the chlorides of Sn, Cu, and Ni that have been volatilized and separated in the chloride volatilization treatment furnace, and recovers Ni chloride individually.

[10] Separation and recovery equipment for valuable elements from waste multilayer ceramic capacitors, wherein the chlorine volatilization treatment furnace is capable of adjusting the internal heating atmosphere to the following temperature ranges: 250°C to 350°C, 450°C to 550°C, and 900°C to 1050°C or 800°C to 1050°C.

[0017]

[11] Separation and recovery equipment for valuable elements from waste multilayer ceramic capacitors, wherein the chlorine volatilization treatment furnace is capable of adjusting the internal heating atmosphere to a temperature range of 450°C or more and 550°C or 900°C or more and 1050°C or 800°C or more and 1050°C.

[12] A separation and recovery facility for valuable elements from waste multilayer ceramic capacitors, characterized in that, in any of the separation and recovery facilities described in [9] to

[11] above, it further has a gas pipeline for circulating chlorine gas discharged from the chloride recovery facility to a chloride volatilization treatment furnace.

[13] In any of the separation and recovery equipment described in [9] to

[12] above, the chloride recovery equipment is characterized in that it cools the chlorides of metal elements and recovers them as solid chlorides, thereby providing equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors.

[0018]

[14] A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed after or before / after the pulverization step, in which the waste multilayer ceramic capacitor is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the metal elements contained in the waste multilayer ceramic capacitor as chlorides. A method for producing chlorides of valuable elements, characterized by having a chloride recovery step for recovering the chlorides of metal elements separated by volatilization in the chloride volatilization step.

[0019]

[15] A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed to volatilize and separate Sn, Cu, and Ni contained in the waste multilayer ceramic capacitor as chlorides by reacting the waste multilayer ceramic capacitor, which has undergone the pulverization step, with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated. A method for producing chlorides of valuable elements, characterized by having a chloride recovery step in which, from the chlorides of Sn, Cu, and Ni separated by volatilization in the chloride volatilization step, Sn chloride and Cu chloride are recovered individually, or both chlorides are recovered together, and Ni chloride is recovered individually.

[0020]

[16] A first chloride volatilization step is performed in which the waste multilayer ceramic capacitor is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, without crushing the waste multilayer ceramic capacitor, thereby volatilizing and separating Sn and Cu contained in the external electrodes of the waste multilayer ceramic capacitor as chlorides, A pulverization step for pulverizing the waste multilayer ceramic capacitor that has undergone the first chloride volatilization step, A second chlorine volatilization step is performed in which the waste multilayer ceramic capacitor that has undergone the crushing step is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the Ni contained in the waste multilayer ceramic capacitor as chloride. A first chloride recovery step in which the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization step are recovered individually or both chlorides are recovered together, A method for producing chlorides of valuable elements, characterized by having a second chloride recovery step for individually recovering the Ni chlorides separated by volatilization in the second chloride volatilization step. [Effects of the Invention]

[0021] According to the present invention, valuable metal elements can be efficiently separated and recovered from waste MLCCs with a high recovery rate using a relatively simple process. Furthermore, the valuable metal elements can be recovered in the form of solid chlorides by a dry method, and in particular, Ni, the main valuable metal element, has the advantage of being recoverable (directly manufactured) in the form of anhydrous nickel chloride, which is a raw material for nickel fine powder. Furthermore, in the present invention, the method of performing a two-stage chlorine volatilization process with a crushing process of waste MLCC in between can separate and recover Ni with a particularly high recovery rate. [Brief explanation of the drawing]

[0022] [Figure 1] A schematic partial cross-sectional perspective view showing the MLCC that is the target of processing in this invention. [Figure 2] An explanatory diagram showing the overall processing flow of one embodiment of the present invention. [Figure 3] Figure 2 shows a detailed diagram illustrating the chloride volatilization process (B) and the chloride recovery process (C) within the processing flow. [Figure 4] An explanatory diagram showing the overall processing flow of another embodiment of the present invention. [Figure 5] Figure 4 shows an explanatory diagram illustrating the details of the first chloride volatilization process (B1) and the first chloride recovery process (C1) within the processing flow. [Figure 6] This graph shows the results of a chloride volatilization test conducted on pulverized MLCC at processing temperatures ranging from 400°C to 1000°C, investigating the relationship between processing temperature and the volatilization rate of metal elements. [Figure 7] This graph shows the results of a chloride volatilization test conducted on MLCCs in their original, unpulverized form at processing temperatures ranging from 400°C to 1000°C, investigating the relationship between processing temperature and the volatilization rate of metal elements. [Figure 8] This graph shows the results of a chloride volatilization test conducted on MLCCs in their original, unpulverized form, at 400°C (Figure 8(a)) and 500°C (Figure 8(b)), with varying treatment times, to investigate the relationship between treatment time and the volatilization rate of metal elements. [Figure 9]This graph shows the results of investigating the relationship between treatment temperature and the volatilization rate of Ni in MLCCs that had been subjected to chlorine volatilization treatment at low to medium heating temperatures while still in their unpulverized product form. The pulverized MLCCs were then subjected to chlorine volatilization tests at treatment temperatures of 800°C to 1000°C. [Figure 10] This diagram schematically illustrates one embodiment of the separation and recovery equipment of the present invention. [Figure 11] A schematic diagram showing the test chlorination apparatus used in the examples. [Modes for carrying out the invention]

[0023] The present invention relates to a method and apparatus for separating and recovering valuable elements from waste multilayer ceramic capacitors. Here, waste multilayer ceramic capacitors refer to discarded multilayer ceramic capacitors or their components, and include, for example, multilayer ceramic capacitors recovered from discarded electronic equipment (such as electronic circuit boards), defective products generated in the manufacturing process, and scrap generated in the manufacturing process (such as pieces of laminated sheets). For the sake of convenience, multilayer ceramic capacitors will be referred to as "MLCCs" and waste multilayer ceramic capacitors as "waste MLCCs".

[0024] Figure 1 is a schematic partial cross-sectional perspective view showing an example of an MLCC that is the target of processing in the present invention. An MLCC mainly consists of a dielectric 50, an internal electrode 60, and an external electrode 70 (end electrode), and has a structure in which the dielectric 50 and the internal electrode 60 are alternately stacked and integrally sintered. Generally, barium titanate (BaTiO3) is used for the dielectric 50, and Ni is used for the internal electrode 60. The external electrode 70 consists of a plating layer or an under electrode, and generally contains Sn, Cu, and Ni as constituent materials. Although some MLCCs may have different structures and compositions depending on the product, all MLCCs have in common the structure in which the dielectric 50 and the internal electrode 60 are alternately stacked and integrally sintered.

[0025] This invention relates to a method for separating and recovering valuable metal elements from waste MLCCs using the chloride volatilization method. The chloride volatilization method is a method of separating specific elements by converting them into chlorides with high vapor pressure and then volatilizing them. Compared to general volatilization smelting, it is an energy-saving process that requires less energy for volatilization. The separation and recovery method of the present invention has as its basic configuration a grinding step (A) in which waste MLCC is ground up, a chloride volatilization step (B) in which waste MLCC is subjected to chloride volatilization treatment after or before / after the grinding step, and a chloride recovery step (C) in which the chlorides of metal elements separated by volatilization in the chloride volatilization step are recovered. In the chloride volatilization process (B), the chloride volatilization treatment is carried out by reacting the metal elements contained in the waste MLCC with chlorine gas to volatilize them as low-boiling point chlorides.

[0026] In this invention, it is essential to pulverize the waste MLCC in the pulverization step (A). As mentioned earlier, even if the waste MLCC is subjected to chlorine volatilization treatment without pulverization, the metal elements of the external electrodes can be recovered, but it is difficult to efficiently recover the metal elements of the internal electrodes, which are firmly sintered and integrated with the dielectric. By pulverizing the waste MLCC beforehand and then performing chlorine volatilization treatment, the metal elements constituting the internal electrodes can be efficiently brought into contact with chlorine gas, and the recovery rate (volatilization rate) of the metal elements of the internal electrodes can be significantly improved compared to the case without the pulverization step. In the grinding process (A), it is desirable to grind the material to a certain degree of fineness in order to improve its reactivity with chlorine gas in the subsequent chlorine volatilization process (B), but the grinding particle size only needs to be sufficient to improve the contact efficiency with chlorine gas. Generally, the grinding particle size is preferably 100 μm or less in average particle size, and more preferably 50 μm or less. Here, the average particle size is the average particle size D50 (μm) measured wet using a laser diffraction particle size distribution analyzer.

[0027] In the chloride volatilization process (B), the waste MLCC is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the metal elements contained in the waste MLCC as chlorides. That is, since the temperature at which the chlorides of metal elements volatilize (boiling point) differs depending on the type of metal element, the temperature of the heated atmosphere is controlled according to the metal elements to be separated and recovered (i.e., to be volatilized and separated), and the metal elements contained in the waste MLCC are volatilized and separated as chlorides. Therefore, if there are multiple types of metal elements to be separated and recovered, it is preferable to sequentially control (usually increase the temperature) the heated atmosphere to the temperature at which the chlorides of each metal element volatilize.

[0028] The chloride volatilization process (B) is performed after the grinding process (A) or before and after the grinding process (A). Performing it before and after the grinding process (A) is advantageous because, for example, as will be described later, in order to separate and recover the metal elements of the internal electrodes (e.g., Ni) with a high recovery rate by chloride volatilization after the grinding process, it is sometimes advantageous to volatilize and separate other metal elements (e.g., Sn of the external electrodes) before the grinding process. In the chloride volatilization process (B), the heating atmosphere in which the chloride volatilization treatment is carried out is a non-oxidizing atmosphere, and there are no particular restrictions on the chlorine gas concentration, but generally 90 vol% or higher is preferred, and 95 vol% or higher is more preferred. Typically, chlorine gas is continuously introduced into the atmosphere in which the chloride volatilization treatment is carried out, and this chlorine gas reacts with the metal elements contained in the waste MLCC, causing the metal elements to volatilize and separate as chlorides. These metal chlorides (gases) are continuously discharged from the system along with unreacted chlorine gas and sent to the next process, the chloride recovery process (C). Furthermore, the chlorine gas introduced into the atmosphere where the chlorine volatilization treatment is performed is usually heated to a predetermined temperature by a preheating means before its introduction.

[0029] In the chloride recovery process (C), the chlorides (gases) of the metal elements separated by volatilization in the chloride volatilization process (B) are cooled and condensed (precipitated) to recover them as solid chlorides. If two or more metal elements are separated by volatilization in separate heating processes in the chloride volatilization process (B) (however, this includes cases where one metal element and a mixture of two metal elements are separated by volatilization), then in this chloride recovery process (C), each metal chloride is recovered separately. The method for cooling and condensing (depositing) the metal chloride gas is arbitrary, but for example, gas-phase granulation methods such as the PVD (Physical Vapor Deposition) method, which induces supersaturation and nucleation through cooling, can be used. The metal chloride (gas) generated in the chloride volatilization process (B) is supplied to the equipment for the chloride recovery process (C) while being kept warm to prevent precipitation and solidification during transport via gas piping, etc.

[0030] The present invention includes a one-stage processing method in which the chloride volatilization process (B) is performed continuously in one step, and a two-stage processing method in which the chloride volatilization process is performed in two steps, with a waste MLCC pulverization process in between. The former will be described below as the first embodiment of the present invention, and the latter as the second embodiment of the present invention. Both embodiments of the method can volatilize and separate Ni, Sn, and Cu from waste MLCC and recover them as valuable elements, and have the advantage of being able to recover high-purity Ni in particular. In this invention, when Ni, Sn, and Cu are separated from waste MLCCs as chlorides and recovered individually, or when only Ni chloride is recovered individually, it is desirable that the metal chloride to be recovered contains as few other metal chlorides as possible and is separated by volatilization with a high volatilization rate. This makes it possible to recover each metal chloride with high purity and high yield (yield: the ratio of the metal element that can be separated and recovered relative to the amount of metal element contained in the waste MLCC). However, depending on the processing conditions of the chloride volatilization process, other metal chlorides may inevitably be included in the metal chloride to be separated and recovered, or the volatilization rate may fall below 100%, and for this reason, the target metal chloride may not be recovered with 100% purity and 100% yield. However, in this invention, such forms are also acceptable and are included as forms of the invention. Therefore, in the chloride recovery process of this invention, "recovering a specific metal chloride individually" includes such forms. If the purity of the recovered metal chloride is less than 100%, post-treatment such as distilling the mixed vapor of chlorides to separate any other metal chlorides present may be performed as needed.

[0031] The first embodiment of the present invention is a one-stage treatment method in which a chloride volatilization treatment is performed continuously in one step, and this one-stage treatment method comprises a grinding step (A) in which waste MLCC is ground up, a chloride volatilization step (B) in which the waste MLCC that has undergone the grinding step (ground up) is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Sn, Cu, and Ni contained in the waste MLCC as chlorides, and a chloride recovery step (C) in which the chlorides of Sn, Cu, and Ni that have been volatilized and separated in the chloride volatilization step are recovered.

[0032] In this one-step treatment method, there are two methods: (i) in the chlorination volatilization step (B), Sn and Cu are volatilized and separated in separate heating steps (heating temperatures) suitable for their respective volatilization separations, and in the chloride recovery step (C), the chlorides of Sn and Cu are recovered individually (separately); (ii) in the chlorination volatilization step (B), Sn and Cu are volatilized and separated together in one heating step (heating temperature), and in the chloride recovery step (C), the chlorides of Sn and Cu are recovered together (i.e., in a mixed state). Note that the methods (i) and (ii) above are common in the volatilization separation and recovery of Ni. When comparing these two methods, the method (i) has the advantage that the chlorides of Sn and Cu can be separated and recovered individually (separately). On the other hand, the method (ii) has the advantage that the temperature control of the chlorination volatilization treatment is simple because the chlorides of Sn and Cu are separated and recovered together.

[0033] First, the method (i) will be described. Figures 2 and 3 show the process flow. Figure 2 shows the overall process flow, and Figure 3 shows the details of the chlorination volatilization step (B) and the chloride recovery step (C) therein. Here, since the details of each treatment in the pulverization step (A), the chlorination volatilization step (B), and the chloride recovery step (C) are as described above, the description thereof will be omitted. Since the volatilization temperatures of the chlorides of Sn, Cu, and Ni are Sn < Cu < Ni, as shown in Figure 3, the chlorination volatilization step (B) has three heating steps according to these metal elements. In the first first-stage heating step (b1) (the step of performing chlorination volatilization treatment at a low heating temperature), Sn is volatilized and separated. When the volatilization separation of Sn is completed, the heating atmosphere is heated up, and in the second-stage heating step (b2) (the step of performing chlorination volatilization treatment at an intermediate heating temperature), Cu is volatilized and separated. Then, when the volatilization separation of Cu is completed, the heating atmosphere is further heated up, and in the third-stage heating step (b3) (the step of performing chlorination volatilization treatment at a high heating temperature), Ni is volatilized and separated. In this way, since Sn, Cu, and Ni contained in the waste MLCC are chlorinated and volatilized under temperature conditions suitable for their respective volatilization separations, each metal element can be volatilized and separated with a high volatilization rate.

[0034] Here, if the processing temperature in the first heating step (b1) is too low, the chlorine volatilization of Sn will not proceed efficiently, while if the processing temperature is too high, chlorine volatilization of Cu will occur, making it difficult to separate and recover Sn with high purity. Also, if the processing time is too short, the chlorine volatilization of Sn will not proceed sufficiently, while if the processing time is too long, productivity will decrease. Furthermore, if the processing temperature in the second heating step (b2) is too low, the chlorine volatilization of Cu will not proceed efficiently, while if the processing temperature is too high, chlorine volatilization of Ni will occur, resulting in a large Ni loss, which will decrease the Ni yield in the subsequent third heating step (b3). It will also become difficult to separate and recover Cu with high purity. Furthermore, if the processing time is too short, the chlorine volatilization of Cu will not proceed sufficiently, while if the processing time is too long, productivity will decrease. Furthermore, if the processing temperature in the third heating step (b3) is too low, the chlorine volatilization of Ni will not proceed efficiently, while if the processing temperature is too high, there is a risk that Ba and Ti from the barium titanate, which constitutes the dielectric of the waste MLCC, may volatilize. Also, if the processing time is too short, the chlorine volatilization of Ni will not proceed sufficiently, while if the processing time is too long, productivity will decrease.

[0035] From the above viewpoint, it is preferable that the first heating step (b1) to the third heating step (b3) be carried out under the following conditions, for example. That is, as the first heating step (b1), Sn is volatilized and separated as chloride by treating at a temperature of 250°C to 350°C for 0.5 to 5 hours. Then the temperature is raised, and as the second heating step (b2), Cu is volatilized and separated as chloride by treating at a temperature of 450°C to 550°C for 0.5 to 5 hours. Then the temperature is raised, and as the third heating step (b3), Ni is volatilized and separated as chloride by treating at a temperature of 900°C to 1050°C for 0.5 to 5 hours.

[0036] Here, regarding the first heating step (b1), as shown in Example 1 described later, 100% of Sn can be volatilized and separated under the conditions of 300°C × 3hr. However, if the processing temperature is too low, the chlorine volatilization of Sn does not proceed efficiently, and the processing time is only unnecessarily prolonged. Therefore, considering the results of the above example and the boiling point of Sn chloride, the preferred lower limit of the processing temperature was set to 250°C. Figure 6 shows the results of a chlorine volatilization test conducted on pulverized MLCC (pulverized sample with an average particle size of 29 μm) at processing temperatures from 400°C to 1000°C (processing time 1hr) using a test method similar to the example described later, and the relationship between the processing temperature and the volatilization rate of metal elements (the proportion that volatilized from MLCC as metal chlorides). According to this, under the conditions of 400°C × 1hr, the volatilization rate of Sn is 100%, but the volatilization rate of Cu is high at 40%, making it unsuitable for the individual separation and recovery of Sn. Therefore, taking these results and the results of Example 1 described later into consideration, the upper limit of the preferred processing temperature was set to 350°C.

[0037] Furthermore, regarding the second heating step (b2), as shown in Figure 6 (and Example 1 described later), under the conditions of 500°C × 1hr, the volatilization rate of Cu is 95% or more, and the volatilization rate of Ni (Ni loss) is low at 5% or less. In contrast, under the conditions of 400°C × 1hr, the volatilization rate of Cu is low at 40%, while under the conditions of 600°C × 1hr, the volatilization rate of Cu is 100%, but the volatilization rate of Ni (Ni loss) is high at 40%, resulting in excessive Ni loss and making it unsuitable for the individual separation and recovery of Cu. Therefore, taking these results into consideration, the preferred processing temperature range was determined to be 450~550°C.

[0038] Furthermore, regarding the third heating step (b3), as shown in Figure 6, the volatilization rate of Ni is 83% under the condition of 1000°C × 1hr (in Example 1 described later, the Ni yield is 78% due to Ni loss in the second heating step (b2)), and it is even lower under the condition of 900°C × 1hr. However, it is thought that the volatilization rate can be increased by sufficiently extending the processing time. On the other hand, processing temperatures significantly exceeding 1000°C are undesirable because they may cause chlorine volatilization of Ba, Ti, etc., which should remain as post-processing residue (solid), potentially reducing the purity of the Ni that is separated by volatilization. For this reason, the preferred processing temperature range was set to 900~1050°C. Note that the above-mentioned first heating steps (b1) to third heating steps (b3) differ only in temperature conditions; all other conditions can remain the same. Furthermore, once the chlorination volatilization process (B) is completed, solid compounds derived from materials other than Sn, Cu, and Ni among the constituent materials of the waste MLCC (for example, compounds such as Ba and Ti derived from barium titanate, which constitutes the dielectric) remain in the system as post-treatment residue (which may in some cases include small amounts of Sn, Cu, and Ni that have not been separated by volatilization), and are removed from the system.

[0039] As shown in Figure 3, the chloride recovery process (C) receives the Sn chloride, Cu chloride, and Ni chloride that were sequentially separated by volatilization in the first stage heating process (b1), second stage heating process (b2), and third stage heating process (b3) of the chloride volatilization process (B), and these metal chlorides are recovered individually (separately). The gas sent from the chloride volatilization process (B) to the chloride recovery process (C) contains not only the metal chlorides (gases) generated in the chloride volatilization process (B) but also unreacted chlorine gas. However, the chlorine gas remaining after the metal chlorides (gases) are precipitated and solidified in the chloride recovery process (C) is recovered and usually reused (recycled) in the chloride volatilization process (B).

[0040] Next, we will explain method (ii) above. Details of each process in the crushing process (A), the chloride volatilization process (B), and the chloride recovery process (C) are as previously described, so we will omit their explanation. Furthermore, since the process flow can be seen in Figures 2 and 3, we will also omit illustrating the process flow for method (ii). In this method, the chloride volatilization process (B) has two heating steps. The first heating step (b 10 )(A process in which chlorine volatilization treatment is performed at an intermediate heating temperature corresponding to the heating temperature of the second heating step (b2) of the method (i) above) to volatilize and separate Sn and Cu, and once the volatilization and separation of Sn and Cu is complete, the heating atmosphere is raised to perform the second heating step (b 20 Ni is volatilized and separated in a process that involves chlorination volatilization at a high heating temperature. In this case as well, since Sn+Cu and Ni contained in the waste MLCC are chlorinated and volatilized under temperature conditions suitable for the volatilization of each element, each metal element can be volatilized and separated at a high volatilization rate.

[0041] Here, the above first heating step (b 10 If the processing temperature is too low, the chlorine volatilization of Sn and Cu will not proceed efficiently, while if the processing temperature is too high, chlorine volatilization of Ni will occur, resulting in a large loss of Ni. 20 The Ni yield in this process decreases. It also becomes difficult to separate and recover Sn+Cu with high purity. Furthermore, if the processing time is too short, the chlorine volatilization of Sn and Cu does not proceed sufficiently, while if the processing time is too long, productivity decreases. In addition, the above second heating step (b 20 If the processing temperature is too low, the chlorine volatilization of Ni will not proceed efficiently, while if the processing temperature is too high, there is a risk that the barium titanate and Ti components of the dielectric of the waste MLCC will volatilize. Also, if the processing time is too short, the chlorine volatilization of Ni will not proceed sufficiently, while if the processing time is too long, productivity will decrease.

[0042] From the above perspective, the first heating step (b 10 ) and the second heating step (b 20 ) is preferably carried out under the following conditions, for example: that is, the first heating step (b10 ) By performing a treatment at a temperature of 450 °C or higher and 550 °C or lower for 0.5 to 5 hours, Sn and Cu are volatilized and separated as chlorides. Then, the temperature is raised, and in the second-stage heating step (b 20 ) By performing a treatment at a temperature of 900 °C or higher and 1050 °C or lower for 0.5 to 5 hours, Ni is volatilized and separated as a chloride.

[0043] Here, in the first-stage heating step (b 10 ), Sn and Cu are volatilized and separated as chlorides. Since the volatilization temperature of Sn and Cu chlorides is Sn < Cu, it can be determined in accordance with the chlorination volatilization of Cu. For this reason, for the same reason as the treatment temperature in the second-stage heating step (b2) in the method (i) above, the preferable treatment temperature range is set to 450 to 550 °C. Also, for the second-stage heating step (b 20 ), for the same reason as the treatment temperature in the third-stage heating step (b3) in the method (i) above, the preferable treatment temperature range is set to 900 to 1050 °C. In the chloride recovery step (C), the chlorides of Sn + Cu chloride and Ni chloride that are sequentially volatilized and separated in the first-stage heating step (b 10 ) and the second-stage heating step (b 20 ) of the chlorination volatilization step (B) are sent, the chlorides of Sn and Cu are recovered together (i.e., in a mixed state), and the Ni chloride is recovered individually.

[0044] Next, as described above, the second form of the present invention is a two-stage treatment method in which the chlorination volatilization treatment is performed in two stages with the pulverization step of the waste MLCC interposed therebetween. After performing the chlorination volatilization treatment without pulverizing the waste MLCC to volatilize and separate the metal elements (mainly Sn, Cu) of the external electrode, the waste MLCC is pulverized, and then, the chlorination volatilization treatment is performed again to volatilize and separate Ni of the internal electrode. The present inventors repeated experiments and studies to find conditions under which the metal elements contained in the waste MLCC can be efficiently volatilized and separated with a high recovery rate. As a result, the following findings were obtained, and the two-stage treatment method was completed.

[0045] First, when waste MLCCs are subjected to chlorine volatilization treatment without being crushed, the Cu and Sn in the external electrodes can be separated by volatilization with a high volatilization rate even at heating temperatures of around 500°C. In contrast, the Ni in the internal electrodes, which is firmly sintered and integrated with the dielectric, is difficult to separate by volatilization even when heated to 1000°C unless the waste MLCCs are crushed (Finding 1). On the other hand, when Ni is volatilized in the presence of Sn, the volatilization rate of Ni is lower compared to when Ni is volatilized in the absence of Sn (Finding 2). In the experiment, when unpulverized waste MLCC was heated to 500°C to volatilize and separate Sn and Cu from the external electrode, and then the resulting pulverized sample (average particle size 25 μm) was heated and held at 800°C to 1000°C for 1 hour, almost all of the Ni was volatilized and separated at 900°C. In contrast, when a sample of waste MLCC that had been pulverized from the beginning (average particle size 29 μm) was heated and held at 600°C to 1000°C for 1 hour, the volatilization rate of Ni was higher than that of the unpulverized sample, but even when heated to 1000°C, the volatilization rate was only about 80%. The reason for this is thought to be that, under conditions where BaTiO3 (a constituent material of the dielectric) and Cl2 react easily in the presence of Sn, Sn acts as a deoxidizing agent for BaO, promoting the chlorination of Ba at low temperatures, and the melting of BaCl2 at high temperatures inhibits the diffusion of chlorine (→ inhibits the chlorination of Ni).

[0046] Based on the above findings, it was found that by first volatilizing the waste MLCC by applying a chloride volatilization treatment without crushing it to separate the Sn and Cu from the external electrodes, then crushing the waste MLCC, and finally applying a chloride volatilization treatment again to separate the Ni from the internal electrodes (i.e., a two-stage treatment method), the Ni from the waste MLCC can be efficiently volatilized and recovered with a high volatilization rate. This two-stage processing method includes: a first chloride volatilization step (B1) in which waste MLCCs are reacted with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, without pulverizing the waste MLCCs, thereby volatilizing and separating Sn and Cu contained in the external electrodes of the waste MLCCs as chlorides; a pulverization step (Ax) in which the waste MLCCs that have undergone the first chloride volatilization step are pulverized; a second chloride volatilization step (B2) in which the waste MLCCs that have undergone the pulverization step (pulverized) are reacted with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Ni contained in the waste MLCCs as chlorides; a first chloride recovery step (C1) in which the chlorides of Sn and Cu volatilized and separated in the first chloride volatilization step (B1) are recovered; and a second chloride recovery step (C2) in which the chlorides of Ni volatilized and separated in the second chloride volatilization step (B2) are recovered.

[0047] This two-stage processing method also has two variations: (I) In the first chloride volatilization step (B1), Sn and Cu are volatilized and separated using separate heating steps (heating temperatures) suitable for their respective volatilization separation, and in the first chloride recovery step (C1), the Sn chloride and Cu chloride are recovered individually (separately); (II) In the first chloride volatilization step (B1), Sn and Cu are volatilized and separated together using a single heating step (heating temperature), and in the first chloride recovery step (C1), the Sn chloride and Cu chloride are recovered together (i.e., in a mixed state). Note that methods (I) and (II) above have commonalities in the volatilization separation and recovery of Ni. When comparing these two methods, method (I) above has the advantage of being able to separate and recover Sn and Cu chlorides individually, while method (II) above has the advantage of being able to separate and recover Sn and Cu chlorides together, thus simplifying temperature control during the chloride volatilization process.

[0048] First, let's explain method (I) above. Figures 4 and 5 show the process flow. Figure 4 shows the overall process flow, and Figure 5 shows the details of the first chlorination volatilization step (B1) and the first chloride recovery step (C1) therein. Here, the details of each process in the pulverization step (Ax), the first and second chlorination volatilization steps (B1), (B2), and the first and second chloride recovery steps (C1), (C2) are the same as those of the pulverization step (A), chlorination volatilization step (B), and chloride recovery step (C) described above, so the description thereof is omitted. Since the volatilization temperatures of the chlorides of Sn, Cu, and Ni are Sn < Cu < Ni, as shown in Figure 5, the first chlorination volatilization step (B1) for volatilization separation of Sn and Cu has a two-stage heating process according to these metal elements. In the first stage heating step (b11) (the step of performing chlorination volatilization treatment at a low heating temperature), Sn is volatilized and separated. When the volatilization separation of Sn is completed, the heating atmosphere is heated up, and in the second stage heating step (b12) (the step of performing chlorination volatilization treatment at an intermediate heating temperature), Cu is volatilized and separated. In addition, in the second chlorination volatilization step (B2) performed with the pulverization step (Ax) interposed therebetween, the heating atmosphere temperature is further increased, and Ni is volatilized and separated as the third stage heating step (b13) (the step of performing chlorination volatilization treatment at a high heating temperature) (since the third stage heating step (b13) = the second chlorination volatilization step (B2), the third stage heating step (b13) is not shown). Thus, since Sn, Cu, and Ni contained in the waste MLCC are chlorinated and volatilized under temperature conditions suitable for their respective volatilization separations, each metal element can be volatilized and separated with a high volatilization rate.

[0049] Here, if the processing temperature in the first heating step (b11) is too low, the chlorine volatilization of Sn will not proceed efficiently, while if the processing temperature is too high, chlorine volatilization of Cu will occur, making it difficult to separate and recover Sn with high purity. Also, if the processing time is too short, the chlorine volatilization of Sn will not proceed sufficiently, while if the processing time is too long, productivity will decrease. Furthermore, if the processing temperature in the second heating step (b12) is too low, the chlorine volatilization of Cu will not proceed efficiently, while if the processing temperature is too high, chlorine volatilization of Ni will occur, resulting in a large Ni loss, which will decrease the Ni yield in the subsequent third heating step (b13) (second chlorine volatilization step (B2)). Furthermore, it will also become difficult to separate and recover Cu with high purity. Also, if the processing time is too short, the chlorine volatilization of Cu will not proceed sufficiently, while if the processing time is too long, productivity will decrease. Furthermore, if the processing temperature in the third heating step (b13) (second chlorine volatilization step (B2)) is too low, the chlorine volatilization of Ni will not proceed efficiently. On the other hand, if the processing temperature is too high, there is a risk that Ba and Ti from the barium titanate, which constitutes the dielectric of the waste MLCC, may volatilize. Also, if the processing time is too short, the chlorine volatilization of Ni will not proceed sufficiently. On the other hand, if the processing time is too long, productivity will decrease.

[0050] From the above viewpoint, it is preferable that the first heating step (b11) to the third heating step (b13) be carried out under the following conditions, for example. That is, in the first chloride volatilization step (B1), as the first heating step (b11), Sn is volatilized and separated as chloride by treating at a temperature of 250°C to 350°C for 0.5 to 5 hours. Then the temperature is raised, and as the second heating step (b12), Cu is volatilized and separated as chloride by treating at a temperature of 450°C to 550°C for 0.5 to 5 hours. Furthermore, in the second chloride volatilization step (B2) after the grinding step (Ax), the treatment temperature is raised further, and as the third heating step (b13), Ni is volatilized and separated as chloride by treating at a temperature of 800°C to (more preferably 900°C to 1050°C) for 0.5 to 3 hours.

[0051] Here, regarding the first stage heating step (b11) of the first chloride volatilization step (B1), as shown in Example 2 described later, 100% of Sn can be volatilized and separated under the condition of 300°C × 3hr. However, if the processing temperature is too low, the chlorine volatilization of Sn will not proceed efficiently, and the processing time will only be unnecessarily prolonged. Therefore, considering the results of the above example and the boiling point of Sn chloride, the preferred lower limit of the processing temperature was set to 250°C. Figure 7 shows the results of a chloride volatilization test conducted on MLCC in its original, uncrushed product form at processing temperatures from 400°C to 1000°C (processing time 1hr) using a test method similar to the example described later, and the relationship between the processing temperature and the volatilization rate of the metal element was investigated. Figure 8 also shows the results of a chloride volatilization test conducted on MLCC in its original, uncrushed product form at 400°C (Figure 8(a)) and 500°C (Figure 8(b)) with varying processing times (processing time 1 to 3hr), and the relationship between the processing time and the volatilization rate of the metal element was investigated. According to Figures 7 and 8, under the conditions of 400°C × 1hr, the volatilization rate of Sn is nearly 90%, but the volatilization rate of Cu is nearly 20%, making it unsuitable for the individual separation and recovery of Sn. Therefore, taking these results into consideration, along with the results of Example 2 described later, the upper limit of the preferred processing temperature was set to 350°C.

[0052] Furthermore, regarding the second heating step (b12), as shown in Figures 7 and 8 (and in Example 2 described later), under the condition of 500°C × 1hr, the volatilization rate of Cu is 90% or more, and the volatilization rate of Ni (Ni loss) is low at 3% or less. Also, under the condition of 500°C × 3hr, the volatilization rate of Cu is 100%, and the volatilization rate of Ni (Ni loss) is suppressed to 7%. On the other hand, under the condition of 400°C × 1~3hr, the volatilization rate of Cu is low at 20~30%, and under the condition of 600°C × 1hr, the volatilization rate of Cu is 100%, but the volatilization rate of Ni (Ni loss) is high at 20%, which is too high a Ni loss and unsuitable for the individual separation and recovery of Cu. Therefore, taking these results into consideration, the preferred processing temperature range was set to 450~550°C.

[0053] Furthermore, the third stage heating process (b13), which is the second chloride volatilization process (B2), was carried out as follows. Figure 9 shows the results of investigating the relationship between the treatment temperature and the volatilization rate of Ni. This was done by pulverizing MLCCs that had undergone the chloride volatilization treatment in the first stage heating process (b11) and the second stage heating process (b12) in the first chloride volatilization process (B1) while remaining in their unpulverized product form. A chloride volatilization test was then performed on these pulverized MLCCs (pulverized samples with an average particle size of 25 μm) at treatment temperatures of 800°C to 1000°C (treatment time of 1 hr) according to the test method described later in the examples, and the relationship between the treatment temperature and the volatilization rate of Ni was investigated. As shown in Figure 9, the volatilization rate of Ni was 80% under the condition of 800°C × 1 hr, over 95% under the condition of 900°C × 1 hr, and 100% under the condition of 1000°C × 1 hr. On the other hand, processing temperatures significantly exceeding 1000°C are undesirable because they may cause chlorine volatilization of Ba, Ti, and other elements that should remain as post-processing residues (solids), potentially reducing the purity of Ni that is separated by volatilization. For this reason, the preferred processing temperature range was set to 800-1050°C, more preferably 900-1050°C. Furthermore, as shown in Figure 9, in the third heating step (b13) of the two-stage processing method, the Ni volatilization rate is 100% under the condition of 1000°C × 1 hr, so the processing time is considered to be shorter compared to the single-stage processing method, and for this reason, the preferred upper limit for the processing time was set to 3 hr. Note that the first heating step (b11) to the third heating step (b13) described above differ only in temperature conditions; all other conditions can remain the same. Furthermore, once the chlorination volatilization process (B1) is completed, solid compounds derived from materials other than Sn, Cu, and Ni among the constituent materials of the waste MLCC (for example, compounds such as Ba and Ti derived from barium titanate, which constitutes the dielectric) remain in the system as post-treatment residue (which may sometimes include small amounts of Sn, Cu, and Ni that have not been separated by volatilization), and are removed from the system.

[0054] As shown in Figure 5, the chloride recovery process (C1) receives the Sn chloride and Cu chloride that were sequentially separated by volatilization in the first heating process (b11) and the second heating process (b12) of the chloride volatilization process (B1), and these metal chlorides are recovered individually (separately). Furthermore, the chloride recovery process (C2) receives the chloride volatilization process (B2) (Ni chloride separated by volatilization in the third heating process (b13)), and this Ni chloride is recovered individually. The gas sent from the chloride volatilization process (B1) and (B2) to the chloride recovery process (C1) and (C2) contains not only the metal chlorides (gases) generated in the chloride volatilization process (B1) and (B2) but also unreacted chlorine gas. However, the chlorine gas remaining after the metal chlorides (gases) have been precipitated and solidified in the chloride recovery process (C1) and (C2) is recovered and is usually reused (recycled) in the chloride volatilization process (B1) and (B2).

[0055] Next, we will explain method (II) described above. The details of each process in the crushing process (Ax), the first and second chloride volatilization processes (B1) and (B2), and the first and second chloride recovery processes (C1) and (C2) are the same as those described earlier in the crushing process (A), chloride volatilization process (B), and chloride recovery process (C), so we will omit their explanation. Also, since the process flow can be seen in Figures 4 and 5, we will omit illustrating the process flow for method (II). In this method, the first chloride volatilization step (B1) is performed in the first heating step (b1 10 )(A step in which chlorine volatilization treatment is performed at an intermediate heating temperature corresponding to the heating temperature of the second stage heating step (b12) of the method (I) above) to volatilize and separate Sn and Cu together. In addition, in the second chlorine volatilization step (B2), the second stage heating step (b1 20 Ni is volatilized and separated as a process of chlorine volatilization treatment at a high heating temperature. In this case as well, since Sn+Cu and Ni contained in the waste MLCC are chlorinated and volatilized under temperature conditions suitable for the volatilization of each, each metal element can be volatilized and separated with a high volatilization rate.

[0056] Here, the first chlorine volatilization step (B1) (first stage heating step (b1 10 If the processing temperature is too low, the chlorine volatilization of Sn and Cu will not proceed efficiently, on the other hand, if the processing temperature is too high, the chlorine volatilization of Ni will occur and the Ni loss will be large, so the subsequent second heating step (b1 20The Ni yield will decrease. Also, it becomes difficult to separate and recover Sn + Cu with high purity. Further, if the treatment time is too short, the chlorination volatilization of Sn and Cu will not proceed sufficiently, while if the treatment time is too long, the productivity will decrease. Also, in the second chlorination volatilization step (B2) (second-stage heating step (b1 20 )), if the treatment temperature is too low, the chlorination volatilization of Ni will not proceed efficiently, while if the treatment temperature is too high, there is a risk that Ba, Ti, etc. of barium titanate constituting the dielectric of the waste MLCC will undergo chlorination volatilization. Also, if the treatment time is too short, the chlorination volatilization of Ni will not proceed sufficiently, while if the treatment time is too long, the productivity will decrease.

[0057] From the above viewpoints, the first chlorination volatilization step (B1) (first-stage heating step (b1 10 )) and the second chlorination volatilization step (B2) (second-stage heating step (b1 20 )) are preferably carried out under the following conditions. That is, in the first chlorination volatilization step (B1), Sn and Cu are volatilized and separated as chlorides by performing a treatment at a temperature of 450°C or higher and 550°C or lower for 0.5 to 5 hours. Also, in the second chlorination volatilization step (B2), Ni is volatilized and separated as a chloride by performing a treatment at a temperature of​​​​​​​​​​​In the first chloride recovery process (C1), the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization process (B1) are sent, and the Sn chloride and Cu chloride are recovered together (i.e., in a mixed state). In the second chloride recovery process (C2), the Ni chloride separated by volatilization in the second chloride volatilization process (B2) is sent, and this Ni chloride is recovered individually.

[0059] As described above, the present invention (single-stage processing method, two-stage processing method) allows for the stepwise and selective volatilization and separation of multiple types of metal elements contained in waste MLCCs, and enables the recovery of each metal element with a high recovery rate. Furthermore, since metal elements can be separated and recovered simply by controlling the temperature within the system, the number of steps required can be reduced, and metal elements can be separated and recovered from waste MLCCs in a simple and efficient manner. Furthermore, in particular, with the two-stage processing method, Sn contained in the waste MLCC is separated by volatilization in the first stage of chlorine volatilization treatment, the waste MLCC is crushed, and Ni is separated by volatilization in the second stage of chlorine volatilization treatment. Therefore, Ni can be efficiently separated and recovered with a particularly high volatilization rate (recovery rate).

[0060] Next, the separation and recovery equipment of the present invention will be described. Figure 10 is a schematic diagram illustrating one embodiment of the separation and recovery equipment of the present invention. The separation and recovery equipment of the present invention is equipment used in carrying out the method of the present invention as described above, and consists of a crushing device 1 for crushing waste MLCCs, a chloride volatilization furnace 2 for chlorine volatilization treatment of waste MLCCs at an appropriate timing, and a chloride recovery equipment 3 for recovering the chlorides of metal elements generated by the chloride volatilization treatment of waste MLCCs. The pulverizer 1 can be any device capable of pulverizing waste MLCCs into the powder described above, and for example, one or more known pulverizers can be used.

[0061] The chlorine volatilization furnace 2 performs a process in which waste MLCCs that have been crushed by the crushing device 1 (for example, waste MLCCs in the one-stage processing method described above) or waste MLCCs before and after crushing by the crushing device 1 (for example, waste MLCCs in the two-stage processing method described above) are reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Sn, Cu, and Ni contained in the waste MLCCs as chlorides. For the chloride volatilization treatment furnace 2, for example, a fixed-bed type, a fluidized-bed type, or a mobile-bed type heating furnace can be used, but it is not limited to these as long as it can heat the waste MLCC to a predetermined temperature.

[0062] In the one-stage processing method described above, as shown by the solid arrows in Figure 10 (solid arrows for circled numbers (1) and (2)), waste MLCCs are first supplied to the crushing device 1 for crushing, and then the crushed waste MLCCs are transferred and supplied to the chloride volatilization furnace 2. In the two-stage processing method described above, as shown by the dashed arrows in Figure 10 (dashed arrows for circled numbers (1) to (3)), uncrushed waste MLCCs are supplied to the chloride volatilization furnace 2 for chloride volatilization, then transferred and supplied to the crushing device 1 for crushing, and then returned (transferred and supplied) to the chloride volatilization furnace 2 for chloride volatilization again. The transfer and supply of waste MLCCs between the crushing device 1 and the chloride volatilization furnace 2 can be carried out by appropriate transfer and supply means.

[0063] Chlorine gas is introduced into the chlorine volatilization furnace 2 through gas piping or the like, and it is preferable that the chlorine volatilization furnace 2 has a heating means for controlling the ambient temperature inside the furnace. It is also possible that a preheating device is provided on the furnace inlet side for heating (preheating) the chlorine gas introduced into the furnace. Furthermore, it is preferable that the chlorine gas introduced into the chlorine volatilization furnace 2 is heated to an appropriate temperature by a heating device (not shown) during its transfer through the gas pipeline or the like. It is preferable that the chlorine volatilization furnace 2 is capable of adjusting the internal heating atmosphere to the following temperature ranges: 250°C to 350°C, 450°C to 550°C, 900°C to 1050°C, or 800°C to 1050°C, in order to enable the implementation of the one-stage treatment method (i) or the two-stage treatment method (I) described above. Furthermore, it is preferable that the chlorine volatilization furnace 2 is capable of adjusting the internal heating atmosphere to the following temperature ranges: 450°C to 550°C, 900°C to 1050°C, or 800°C to 1050°C, in order to enable the implementation of the one-stage treatment method (ii) or the two-stage treatment method (II) described above. Typically, the chloride volatilization furnace 2 is equipped with a discharge mechanism for discharging and recovering the post-treatment residue (solid) of waste MLCCs.

[0064] The chloride recovery equipment 3 recovers Sn chloride and Cu chloride individually or together (i.e., in a mixed state) from the Sn, Cu, and Ni chlorides separated by volatilization in the chloride volatilization furnace 2, and recovers Ni chloride individually. In this embodiment, three recovery tanks 4a to 4c are provided to recover Sn, Cu, and Ni chlorides separated by volatilization in the chloride volatilization furnace 2 individually. Gas piping 5 from the chloride volatilization furnace 2 branches off, and each of the branch pipes 5a to 5c is connected to the recovery tanks 4a to 4c. Shut-off valves 8a to 8c and 9a to 9c are provided in each of the branch pipes 5a to 5c connected to the recovery tanks 4a to 4c, and in the exhaust pipes 7 from each of the recovery tanks 4a to 4c, allowing the recovery of metal chlorides to be performed by switching between the recovery tanks 4a to 4c depending on the type of metal chloride (gas) supplied from the chloride volatilization furnace 2. Furthermore, if the Sn chloride and Cu chloride separated by volatilization in the chloride volatilization treatment furnace 2 are recovered together, and the Ni chloride is recovered separately, then two recovery tanks 4 are sufficient.

[0065] The chloride recovery equipment 3 cools the chloride gas of metal elements and recovers it as solid chloride. Preferably, each recovery tank 4a to 4c has the necessary means for this purpose, such as a means for cooling the chloride gas, a means for storing the precipitated and solidified chloride, and a means for transporting it out of the tank. Furthermore, it is preferable to insulate the gas piping 5 (including branch pipes 5a to 5c) leading from the chloride volatilization furnace 2 to the chloride recovery equipment 3 with appropriate heat retention measures to prevent the precipitation of metal elements (chlorides) within the piping.

[0066] The gas supplied from the chloride volatilization furnace 2 to the chloride recovery equipment 3 contains unreacted chlorine gas in addition to chloride gas. After chloride recovery, this chlorine gas is exhausted from the chloride recovery equipment 3 through the exhaust pipe 7, but a gas pipeline 6 is provided to circulate this chlorine gas back to the chloride volatilization furnace 2. This gas pipeline 6 is connected to a gas supply pipe 10 that supplies chlorine gas to the chloride volatilization furnace 2, and is introduced into the chloride volatilization furnace 2 together with newly supplied chlorine gas from this gas supply pipe 10. Furthermore, in order to keep the concentration of impurities in the gas circulating in the gas pipeline 6 below a certain level, a gas exhaust pipe 11 is connected to the gas pipeline 6, and a portion of the circulating gas is extracted from this gas exhaust pipe 11, and after chlorine gas is removed by the scrubber 12, it is exhausted (released).

[0067] Next, the method for producing metal chlorides according to the present invention will be described. This method for producing metal chlorides comprises a grinding step (A) in which waste MLCCs are ground; a chloride volatilization step (B) in which the waste MLCCs are reacted with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, either after or before the grinding step, thereby volatilizing and separating the metal elements contained in the waste MLCCs as chlorides; and a chloride recovery step (C) in which the chlorides of the metal elements volatilized and separated in the chloride volatilization step are recovered. Through these steps, valuable metal element chlorides are produced. Similar to the method for separating and recovering valuable elements described above, this manufacturing method includes a one-stage process (first form) in which the chloride volatilization process (B) is carried out continuously in one step, and a two-stage process (second form) in which the chloride volatilization process is carried out in two steps, with a waste MLCC pulverization process in between. Both methods can volatilize and separate Ni, Sn, and Cu from waste MLCCs and produce their chlorides, and have the advantage of being able to produce high-purity Ni chloride in particular. Since the manufacturing method of the present invention is a dry method, it has the advantage, particularly with respect to Ni chloride, that anhydrous Ni chloride can be directly produced in a simple manufacturing process without going through a drying step.

[0068] The first embodiment of the manufacturing method of the present invention (single-stage processing method) comprises a grinding step (A) for grinding waste MLCCs, a chloride volatilization step (B) in which the waste MLCCs that have undergone the grinding step are reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Sn, Cu, and Ni contained in the waste MLCCs as chlorides, and a chloride recovery step (C) in which, from the chlorides of Sn, Cu, and Ni that have been volatilized and separated in the chloride volatilization step, the Sn chloride and Cu chloride are recovered individually, or both chlorides are recovered together, and the Ni chloride is recovered individually.

[0069] Furthermore, a second embodiment of the manufacturing method of the present invention (two-stage processing method) comprises: a first chloride volatilization step (B1) in which waste MLCCs are reacted with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, without pulverizing the waste MLCCs, thereby volatilizing and separating Sn and Cu contained in the external electrodes of the waste MLCCs as chlorides; a pulverization step (Ax) in which the waste MLCCs that have undergone the first chloride volatilization step are pulverized; a second chloride volatilization step (B2) in which the waste MLCCs that have undergone the pulverization step are reacted with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Ni contained in the waste MLCCs as chlorides; a first chloride recovery step (C1) in which the Sn chloride and Cu chloride volatilized and separated in the first chloride volatilization step are recovered individually, or both chlorides are recovered together; and a second chloride recovery step (C2) in which the Ni chloride volatilized and separated in the second chloride volatilization step is recovered individually. Details of the manufacturing method of the present invention and the manufacturing equipment used in its implementation are as follows: As previously explained, the method and equipment for separating and recovering valuable elements are as described, including the processing flow shown in Figures 2 to 5 and the manufacturing equipment shown in Figure 10. [Examples]

[0070] A test was conducted using commercially available MLCC as the test material, and it was subjected to chlorine volatilization treatment. The test conditions are as follows: ·Test material MLCC (manufactured by Murata Manufacturing Co., Ltd.) 3 pieces MLCC size and weight: L: 1.6mm x W: 0.8mm x T: 0.8mm, 5.5mg / piece ·MLCC composition (mass%) Ni:6.08%,Cu:3.88%, Sn: 1.23%, Ti: 17.7%, Ba: 51.5%, Other (remaining): 19.6% MLCCs were ground using an alumina mortar, and the average particle size of the ground sample was measured using a particle size distribution analyzer (MT3300EX II, Microtrac).

[0071] Figure 11 shows a schematic of the chlorination apparatus used for the test. A quartz boat containing the sample was placed in the center of the heating section of a reaction tube (quartz tube, inner diameter 22 mm) installed in a heater (AS ONE Corporation, TMF-500N). Chlorine gas (purity 99.4%) was introduced from a cylinder at a flow rate of 100 ml / min to perform chlorine volatilization treatment, and the generated metal chloride (gas) was precipitated in the reaction tube on the outlet side of the electric furnace to obtain solid metal chloride. Unreacted chlorine gas was collected in a trap (1M NaOH aq). The test temperature for chlorine volatilization treatment was 300°C to 1000°C, the heating rate was 10°C / min, and the holding time at each treatment temperature was 1 to 3 hours. Figure 11 also shows the heat pattern and gas supply pattern for chlorine volatilization treatment in each test. The gas supplied to the reaction tube was nitrogen gas at the very beginning of the heating process, and then switched to chlorine gas, which was continuously supplied. The point at which the target temperature was reached was defined as HR 0, and the temperature was maintained for 1 to 3 hours from that point for chlorine volatilization treatment. After this 1 to 3 hour treatment was completed, the supply gas was switched to nitrogen gas and the temperature was lowered. After each test, the treated residue was removed from the reaction tube and subjected to component analysis. Based on the analysis results and the original composition of the MLCC, the yield (recovery rate) of each metal element due to chloride volatilization and the purity of the metal in each metal chloride were calculated. Component analysis was performed using atomic absorption spectrophotometers (SHIMADZU, AA-7800 and analytic jena, AA700TG).

[0072] [Example 1] A chlorine volatilization process test was conducted to separate and recover valuable elements from MLCCs using a method equivalent to the one-stage processing method described earlier. In this example, the MLCC test material was subjected to a grinding process (grinding step), followed by a chlorine volatilization process (chlorine volatilization step) using the chlorination apparatus described above. The average particle size of the test material (ground sample) after grinding was 29 μm. The chlorine volatilization process was carried out in three stages: the first heating step to the third heating step. The results, along with the chlorine volatilization conditions, are shown in Table 1. In this embodiment, the Ni yield in the third heating stage was only 78%, but it is thought that the Ni yield could be increased by extending the processing time. Also, although the Sn yield in the first heating stage was 100%, the Cu yield in the second heating stage was only 98%, so the purity of the Ni recovered in the third heating stage was less than 100%. However, referring to test (2) in [Example 2] described later, it is thought that if the processing time in the second heating stage is extended, the Cu yield in the second heating stage will become 100%, and although the Ni loss will be slightly higher in that case, the purity of the Ni recovered in the third heating stage can be made 100%.

[0073] [Table 1]

[0074] [Example 2] A chlorine volatilization process test was conducted to separate and recover valuable elements from MLCCs using a method equivalent to the two-stage processing method described earlier. In this example, the MLCC test material was subjected to chloride volatilization treatment (first chloride volatilization step) in the chlorination apparatus while retaining its product shape, without pulverization. Afterward, it was removed from the chlorination apparatus and pulverized (pulverization step), and the pulverized sample was subjected to chloride volatilization treatment again in the chlorination apparatus (second chloride volatilization step). The average particle size of the test material (pulverized sample) after pulverization was 25 μm. The first chloride volatilization treatment was performed in two stages: a first-stage heating step and a second-stage heating step. The second-stage heating step was performed in two ways: 500°C × 1 hr (test (1)) and 500°C × 3 hr (test (2)). The results, along with the chloride volatilization treatment conditions, are shown in Table 2. In this embodiment, the Ni yield in the third heating stage (second chlorine volatilization stage) is higher than in Example 1. In addition, in Test (2), the Sn yield in the first heating stage and the Cu yield in the second heating stage of the first chlorine volatilization stage were both 100%. In this case, although the Ni loss in the second heating stage is slightly higher, the Ni yield in the third heating stage is 93%, and the Ni purity is 100%.

[0075] [Table 2] [Comparative Example 1] The MLCC test material was subjected to chlorine volatilization treatment in the chlorination apparatus described above under the conditions of 1000°C × 1 hr without pulverization. As a result, the Ni yield was approximately 30%. The yields of Sn and Cu were 100%, but since the entire amount of these was recovered together with the Ni, the Ni purity of the recovered metal chloride was at a very low level. [Explanation of symbols]

[0076] 1. Grinding device 2. Chloride volatilization furnace 3. Chloride recovery equipment 4a~4c Recovery tank 5. Gas piping 5a~5c Branch pipe 6. Gas pipelines 7 Exhaust pipe 8a~8c Shut-off valves 9a~9c Shut-off valves 10 Gas supply pipe

Claims

1. A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed after or before / after the pulverization step, in which the waste multilayer ceramic capacitor is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the metal elements contained in the waste multilayer ceramic capacitor as chlorides. A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized by having a chloride recovery step for recovering the chlorides of metal elements separated by volatilization in the chloride volatilization step.

2. A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed to volatilize and separate Sn, Cu, and Ni contained in the waste multilayer ceramic capacitor as chlorides by reacting the waste multilayer ceramic capacitor, which has undergone the pulverization step, with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated. A method for separating and recovering valuable elements from waste multilayer ceramic capacitors, characterized by having a chloride recovery step in which, from the chlorides of Sn, Cu, and Ni separated by volatilization in the chloride volatilization step, Sn chloride and Cu chloride are recovered individually, or both chlorides are recovered together, and Ni chloride is recovered individually.

3. In the aforementioned chloride volatilization step, Sn is volatilized and separated as chloride by performing a treatment at a temperature of 250°C to 350°C for 0.5 to 5 hours, Cu is volatilized and separated as chloride by performing a treatment at a temperature of 450°C to 550°C for 0.5 to 5 hours, and Ni is volatilized and separated as chloride by performing a treatment at a temperature of 900°C to 1050°C for 0.5 to 5 hours. The method for separating and recovering valuable elements from a waste multilayer ceramic capacitor according to claim 2, characterized in that the chloride recovery step involves individually recovering the chlorides of Sn, Cu, and Ni that were volatilized and separated in the chloride volatilization step.

4. In the aforementioned chloride volatilization step, Sn and Cu are volatilized and separated as chlorides by performing a treatment at a temperature of 450°C to 550°C for 0.5 to 5 hours, and Ni is subsequently volatilized and separated as chlorides by performing a treatment at a temperature of 900°C to 1050°C for 0.5 to 5 hours. The method for separating and recovering valuable elements from a waste multilayer ceramic capacitor according to claim 2, characterized in that, in the chloride recovery step, Sn chloride and Cu chloride are recovered together and Ni chloride is recovered separately from the Sn, Cu, and Ni chlorides separated by volatilization in the chloride volatilization step.

5. A first chloride volatilization step involves reacting the waste multilayer ceramic capacitor with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, without crushing the waste multilayer ceramic capacitor, thereby volatilizing and separating Sn and Cu contained in the external electrodes of the waste multilayer ceramic capacitor as chlorides. A pulverization step for pulverizing the waste multilayer ceramic capacitor that has undergone the first chloride volatilization step, A second chlorine volatilization step is performed in which the waste multilayer ceramic capacitor that has undergone the crushing step is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the Ni contained in the waste multilayer ceramic capacitor as chloride. A first chloride recovery step in which the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization step are recovered individually, or both chlorides are recovered together, A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor, characterized by having a second chloride recovery step for individually recovering Ni chloride separated by volatilization in the second chloride volatilization step.

6. In the first chloride volatilization step, Sn is volatilized and separated as a chloride by performing a treatment at a temperature of 250°C to 350°C for 0.5 to 5 hours, and Cu is subsequently volatilized and separated as a chloride by performing a treatment at a temperature of 450°C to 550°C for 0.5 to 5 hours. In the second chloride volatilization step, Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 800°C to 1050°C for 0.5 to 3 hours. The method for separating and recovering valuable elements from a waste multilayer ceramic capacitor according to claim 5, characterized in that the first chloride recovery step separately recovers the Sn chloride and Cu chloride that were separated by volatilization in the first chloride volatilization step.

7. In the first chloride volatilization step, Sn and Cu are separated by volatilization as chlorides by performing a treatment at a temperature of 450°C to 550°C for 0.5 to 5 hours. In the second chloride volatilization step, Ni is volatilized and separated as a chloride by performing a treatment at a temperature of 800°C to 1050°C for 0.5 to 3 hours. The method for separating and recovering valuable elements from a waste multilayer ceramic capacitor according to claim 5, characterized in that the first chloride recovery step recovers together the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization step.

8. A method for separating and recovering valuable elements from a waste multilayer ceramic capacitor according to any one of claims 1 to 7, characterized in that the chloride recovery step involves cooling the chloride of a metal element and recovering it as a solid chloride.

9. A crushing device for crushing waste multilayer ceramic capacitors, A chlorine volatilization furnace is used to perform a volatilization treatment on waste multilayer ceramic capacitors that have been pulverized by the pulverizing device, or waste multilayer ceramic capacitors before and after pulverization by the pulverizing device, by reacting them with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating Sn, Cu, and Ni contained in the waste multilayer ceramic capacitors as chlorides. A system for separating and recovering valuable elements from waste multilayer ceramic capacitors, characterized by having a chloride recovery facility that recovers Sn chloride and Cu chloride individually, or both chlorides together, from the chlorides of Sn, Cu, and Ni that have been volatilized and separated in the chloride volatilization treatment furnace, and recovers Ni chloride individually.

10. The equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors according to claim 9, characterized in that the chlorine volatilization treatment furnace is capable of adjusting the internal heating atmosphere to the following temperature ranges: 250°C to 350°C, 450°C to 550°C, 900°C to 1050°C, or 800°C to 1050°C.

11. The equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors according to claim 9, characterized in that the chlorine volatilization treatment furnace can adjust the internal heating atmosphere to a temperature range of 450°C to 550°C, 900°C to 1050°C, or 800°C to 1050°C.

12. Furthermore, the equipment for separating and recovering valuable elements from waste multilayer ceramic capacitors according to claim 9, characterized in that it has a gas pipeline for circulating chlorine gas discharged from the chloride recovery equipment to a chloride volatilization treatment furnace.

13. The chloride recovery equipment is characterized by cooling the chlorides of metal elements and recovering them as solid chlorides, as described in any one of 9 to 12, for the separation and recovery of valuable elements from waste multilayer ceramic capacitors.

14. A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed after or before / after the pulverization step, in which the waste multilayer ceramic capacitor is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the metal elements contained in the waste multilayer ceramic capacitor as chlorides. A method for producing chlorides of valuable elements, characterized by having a chloride recovery step for recovering the chlorides of metal elements separated by volatilization in the chloride volatilization step.

15. A crushing process for crushing waste multilayer ceramic capacitors, A chlorine volatilization step is performed to volatilize and separate Sn, Cu, and Ni contained in the waste multilayer ceramic capacitor as chlorides by reacting the waste multilayer ceramic capacitor, which has undergone the pulverization step, with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated. A method for producing chlorides of valuable elements, characterized by having a chloride recovery step in which, from the chlorides of Sn, Cu, and Ni separated by volatilization in the chloride volatilization step, Sn chloride and Cu chloride are recovered individually, or both chlorides are recovered together, and Ni chloride is recovered individually.

16. A first chloride volatilization step involves reacting the waste multilayer ceramic capacitor with chlorine gas in a heated atmosphere with temperature conditions controlled according to the metal elements to be volatilized and separated, without crushing the waste multilayer ceramic capacitor, thereby volatilizing and separating Sn and Cu contained in the external electrodes of the waste multilayer ceramic capacitor as chlorides. A pulverization step for pulverizing the waste multilayer ceramic capacitor that has undergone the first chloride volatilization step, A second chlorine volatilization step is performed in which the waste multilayer ceramic capacitor that has undergone the crushing step is reacted with chlorine gas in a heated atmosphere where the temperature conditions are controlled according to the metal elements to be volatilized and separated, thereby volatilizing and separating the Ni contained in the waste multilayer ceramic capacitor as chloride. A first chloride recovery step in which the Sn chloride and Cu chloride separated by volatilization in the first chloride volatilization step are recovered individually, or both chlorides are recovered together, A method for producing chlorides of valuable elements, characterized by having a second chloride recovery step for individually recovering the Ni chlorides separated by volatilization in the second chloride volatilization step.

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