Treatment equipment and treatment method

Abstract

To provide a treatment apparatus and a treatment method capable of performing mass decomposition treatment (destruction treatment) of PFOS and / or PFOA by utilizing (diverting) a treatment apparatus has have been operating in cement production from the past, without generating harmful substances in the process of that treatment.SOLUTION: A treatment apparatus 10 of the present disclosure includes: a preheater 20 that preheats a cement raw material pulverized by a raw material mill; a rotary kiln 40 (one example of a kiln) to which the preheater 20 is connected at a kiln inlet part 45, and that fires the cement raw material preheated by the preheater 20 to generate a clinker; and a delivery pipe 55 disposed in the kiln inlet part 45, having a delivery port 56 that protrudes toward the internal part of the kiln inlet part 45, to which an aqueous mixture AM containing PFOS and / or PFOA is supplied and from which the aqueous mixture AM is discharged toward the internal part of the kiln inlet part 45. The aqueous mixture AM is discharged from the delivery port 56 of the delivery pipe 55 simultaneously while generating the clinker.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a treatment facility and a treatment method for decomposing (destroying) PFOS and / or PFOA by incinerating an aqueous mixture containing PFOS and / or PFOA. [Background technology]

[0002] PFOS and PFOA are known as perfluorooctane sulfonic acid and perfluorooctanoic acid, respectively, and recent research has revealed that these substances are carcinogenic, making them a social issue.

[0003] These chemicals are widely used in various industrial processes and in products such as household goods, raising concerns about their environmental impact and potential health risks. Furthermore, PFOS and PFOA have a highly stable chemical structure, making them difficult to decompose using conventional treatment methods and remaining in the environment for long periods of time. Therefore, there is a strong social demand for safe and efficient decomposition processes for the existing PFOS and PFOA that have been widely used in society to date.

[0004] An apparatus for destroying conventional fluorinated organic compounds (e.g., PFAS) is known that includes a first inlet conduit for passing a PFAS-containing aqueous stream through a mixing joint, a second inlet conduit for passing a heated stream of clean water to the mixed stream, a conduit connecting the mixing tee to the inlet of an SCWO reactor, and an outlet of the SCWO reactor connected to a salt separator (see, for example, Patent Document 1).

[0005] In the apparatus, the salt separator includes a effluent outlet configured to pass clean water through a heat exchanger configured to heat the clean water exiting the heat exchanger and entering a mixing tee. Alternatively, the effluent outlet is configured to pass the effluent through the mixing tee. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2022-537895 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when using the technology described in Patent Document 1, it becomes necessary to install new facilities in each area to treat the chemical substances PFOS or PFOA. Furthermore, when treating large quantities, new facilities are required, and the structures are large and complex, which may result in enormous treatment costs.

[0008] On the other hand, if it were possible to utilize (repurpose) facilities already used in normal social production activities for the treatment of PFOS and PFOA, it would be efficient and rational from both social and economic perspectives. By utilizing existing facilities, there would be no need to introduce new facilities, and treatment costs could be reduced. In addition, because these are established technologies, there is also the possibility of reducing the environmental burden.

[0009] By the way, cement facilities play a vital role in society by supplying basic materials for buildings and structures. It is an important infrastructure facility (social function) and has a wide range of benefits.

[0010] One of these is the ability to process large volumes. Cement facilities are configured to quickly supply the cement needed for building materials through automated production lines. Cement facilities also have advantages when it comes to processing industrial waste. Waste generated at construction sites and other places can be reused as a component of cement, and processing that industrial waste as a raw material for cement at cement facilities makes it possible to reduce waste and make effective use of resources. Furthermore, in recent years, technology has advanced to recover energy from industrial waste processing, and it is now possible to convert waste into a useful energy resource while minimizing the environmental impact.

[0011] As such, cement facilities have various advantages, and it can be said that there is room for improvement in the utilization of cement facilities in the treatment technology for PFOS and / or PFOA.

[0012] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a treatment facility and a treatment method that can decompose (destroy) a large amount of PFOS and / or PFOA without generating harmful substances during the treatment process, by utilizing (reusing) treatment facilities that have been in operation for some time in cement production. [Means for solving the problem]

[0013] The above-mentioned object of the present invention can be achieved by the following configuration. [1] a preheater for preheating the cement raw material to be ground in the raw material mill; a kiln in which the preheater is connected to the bottom of the kiln and which burns the cement raw materials preheated by the preheater to produce clinker; a discharge pipe disposed in the kiln end portion, the discharge port of which projects toward the inside of the kiln end portion, through which an aqueous mixture containing PFOS and / or PFOA is supplied and which discharges the aqueous mixture from the discharge port toward the inside of the kiln end portion; while generating the clinker, the aqueous mixture is simultaneously discharged from the discharge port of the discharge pipe. Processing equipment. [2] An exhaust duct standing vertically upward is connected to the kiln buttock, The exhaust duct allows exhaust gas generated in the kiln to flow through, The discharge pipe is disposed on the wall surface of the kiln bottom portion, which is opposite to the main body of the kiln and located on the exhaust duct side, based on the intersection of the main body of the kiln, the main body of the exhaust duct, and the first direction which is the extension direction of the kiln and the second direction which is the extension direction of the exhaust duct. [1] The processing equipment described in [1]. [3] An exhaust duct standing vertically upward is connected to the kiln buttock, The exhaust duct allows exhaust gas generated in the kiln to flow through, The discharge port is offset toward the opposite side of the main body of the kiln in the internal space of the kiln bottom portion, based on the main body of the kiln, the main body of the exhaust duct, and the intersection of the first direction which is the extension direction of the kiln and the second direction which is the extension direction of the exhaust duct. [1] The processing equipment described in [1]. [4] a central axis of the outlet port in the discharge direction is set to be inclined upward so as to face the main body side of the exhaust duct; [3] The processing equipment described in [3]. [5] The discharge pipe radially discharges the aqueous mixture from the discharge port. [4] The processing equipment described in [4]. [6] a storage tank for storing the aqueous mixture; a pressure pump connected to the discharge pipe for pressure-feeding and supplying the aqueous mixture in the storage tank; [1] The processing equipment described in [1]. [7] the pressure pump continuously supplies the aqueous mixture to the discharge pipe; [6] The processing equipment described in [6]. [8] a preheater for preheating the cement raw material to be ground in the raw material mill; a kiln in which the preheater is connected to the bottom of the kiln and which burns the cement raw materials preheated by the preheater to produce clinker; An exhaust duct connected to the kiln buttock and erected vertically upward, a discharge pipe disposed at a lower end of the exhaust duct, the discharge port of which projects toward the inside of the exhaust duct, the discharge pipe through which an aqueous mixture containing PFOS and / or PFOA is supplied and which discharges the aqueous mixture from the discharge port toward the inside of the exhaust duct, while generating the clinker, the aqueous mixture is simultaneously discharged from the discharge port of the discharge pipe. Processing equipment. [9] a preheating step of preheating the cement raw material to be pulverized in the raw material mill using a preheater; a firing step in which the preheater uses a kiln connected to its bottom end to fire the cement raw materials preheated by the preheater to produce clinker; a discharge step of supplying an aqueous mixture containing PFOS and / or PFOA to a discharge pipe disposed in the kiln bottom section and having a discharge port protruding toward the inside of the kiln bottom section, and discharging the aqueous mixture from the discharge port toward the inside of the kiln bottom section, The preheating step, the baking step, and the ejection step are carried out in parallel. Processing method.

[0014] According to the above-mentioned [1] and [9] configurations, by utilizing (reusing) treatment facilities already in operation for cement production, it is possible to decompose (destroy) PFOS and / or PFOA chemical substances without generating harmful substances during the treatment process. Moreover, since PFOS and / or PFOA are decomposed simultaneously while cement is being produced, treatment can be carried out economically and efficiently. Furthermore, it is possible to treat large quantities of PFOS and / or PFOA. Here, there is a bend (curve) in the flow path between the end of the kiln and the flow path of the exhaust duct, and at this curve, the exhaust gas flowing from the end of the kiln to the exhaust duct flows faster on the outside of the curve than on the inside of the curve. Therefore, according to the configuration [2], the discharged aqueous mixture is incinerated by riding on the flow of the fast-flowing outer exhaust gas, so that destruction is reliably carried out during the decomposition (destruction) process, thereby suppressing the generation of harmful substances. In addition, because the aqueous mixture does not flow toward the kiln, a drop in the operating temperature of the kiln can be suppressed. According to the configuration [3], the aqueous mixture released is treated by riding on the fast-flowing outer exhaust gas, so that the destruction is reliably carried out during the decomposition (destruction) process, thereby suppressing the generation of harmful substances. In addition, because the aqueous mixture does not flow toward the kiln, a drop in the operating temperature of the kiln can be suppressed. According to the configuration [4], the exhaust gas from the kiln can be carried along with the flow of the exhaust gas and contact with the cement raw materials can be minimized, thereby suppressing the impact on cement production and reducing the operating temperature of the kiln. According to the configuration [5] above, it is possible to suppress the cooling of the operating temperature of the kiln, thereby minimizing the operational impact on cement production and increasing the efficiency of the decomposition treatment (destruction treatment) of PFOS and / or PFOA. According to the configuration [6], it is preferable to further include a storage tank for storing the aqueous mixture, and a pressure pump connected to the discharge pipe for pressure-feeding and supplying the aqueous mixture from the storage tank. In this case, the aqueous mixture can be efficiently and continuously supplied to the end of the kiln, allowing for the decomposition (destruction) of a larger amount of PFOS and / or PFOA to be carried out. According to the configuration [7], the aqueous mixture is continuously supplied toward the inside of the kiln end, thereby suppressing the accompanying fluctuations in the temperature load of the equipment and maintaining stable operation of the kiln. The configuration [8] can also achieve the same effects as the configurations [1] and [9]. [Effects of the Invention]

[0015] According to the present invention, by utilizing (reusing) treatment facilities that have been in operation for cement production, PFOS and / or PFOA can be decomposed (destroyed) in large quantities without generating harmful substances during the treatment process.

[0016] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the structure of a processing facility according to a first embodiment of the present invention. [Figure 2] Enlarged view of the area around the kiln end shown in Figure 1 [Figure 3] Further enlarged view of the main part around the discharge port shown in Figure 2 DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, one or more embodiments specifically disclosing a processing facility and a processing method according to the present invention will be described in detail with appropriate reference to the accompanying drawings.

[0019] However, more detailed explanations than necessary may be omitted, for example, detailed explanations of well-known matters or redundant explanations of substantially the same configurations may be omitted, in order to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0020] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Also, each of the accompanying drawings should be referenced according to the orientation of the reference numerals.

[0021] Also, unless otherwise indicated, all numbers expressing parameters, reaction conditions, concentrations of ingredients, and so forth used in this specification and the appended claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending, at least in part, on particular analytical techniques.

[0022] <Terminology> Characterized by the terms "including" or "including" which are synonymous with "comprising" and "containing" "Comprising" is to be interpreted in an inclusive or open-ended sense and does not exclude additional, unrecited elements or method steps. "Comprising" is a term of art used in claim language that means that the named claim element is required, but that other claim elements may be added to form further structure within the scope of the claim.

[0023] Also, as used herein, the phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When the phrase "consisting of (or variations thereof)" appears in a section of the body of a claim rather than immediately following the preamble, it limits only the elements set forth in that section and does not exclude other elements from the claim as a whole. As used herein, the phrase "consisting essentially of" limits the scope of a claim to those elements or method steps specified in addition to those that do not materially affect the main and novel feature(s) of the claimed subject matter.

[0024] With respect to the terms "comprising," "consisting of," and "consisting essentially of," when one of these three terms is used herein, the presently disclosed and claimed subject matter may also include the use of either of the other two terms. Thus, in some embodiments not expressly recited otherwise, any instance of "comprising" may be replaced by "consisting of" or "consisting essentially of."

[0025] The term "process" or "step" may be used explicitly or implicitly in connection with process or method features, but no order or sequence is limited among such explicit processes or steps or among implicit processes or steps unless the order or sequence is stated.

[0026] <PFOSおよびPFOA> The present invention targets PFOS and PFOA. These substances will now be described.

[0027] PFOS (Perfluorooctane Sulfonic Acid) and PFOA (Perfluorooctanoic Acid) are organic fluorine compounds and surfactants with excellent heat, chemical, and stain resistance. They have been used since the 1950s in a variety of fields, including semiconductor manufacturing, metal plating, firefighting foam, termite control, fluororesin manufacturing, textiles, medicine, and food packaging.

[0028] However, in recent years, PFOS and PFOA have become a growing concern for the environment and health, and recent studies have revealed that they are widely distributed in ecosystems. These chemicals have low biodegradability, persist for long periods in soil and water, and can accumulate in living organisms. It has also been pointed out that these chemicals may have adverse effects on humans through the food chain due to bioaccumulation or impacts on ecosystems.

[0029] Animal experiments have suggested the possibility of carcinogenicity, endocrine disruption, and immunosuppression, and international regulations and initiatives are being considered. While the use of these chemicals is being restricted, the reality is that there is an urgent need to decompose (destroy) the existing PFOS and PFOA that are currently in use.

[0030] PFOS and PFOA have been pointed out as having adverse effects on the environment and potential dangers to the human body, and there is a strong social demand for technology to safely destroy and treat these chemicals in large quantities.

[0031] The present invention is directed to the treatment of PFOS and / or PFOA, which generates harmful substances during the treatment process. In order to decompose (destroy) a large amount of waste without any waste, the device has a special configuration as in one or more embodiments described below.

[0032] First Embodiment A first embodiment of a processing facility 10 according to the present invention will be described with reference to FIGS.

[0033] [· Facility Overview] An example of the configuration of a processing facility 10 according to this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an example of the structure of a processing facility 10 according to this embodiment.

[0034] As shown in Fig. 1, the treatment facility 10 of this embodiment is mainly composed of cement equipment. That is, this embodiment (present invention) uses (repurposes) cement equipment to decompose (destroy) PFOS and / or PFOA to detoxify them.

[0035] The treatment facility 10 is a cement clinker burning facility, and includes a preheater 20, a calciner 30, and a rotary kiln 40 (an example of a kiln).

[0036] The rotary kiln 40 heats cement raw materials that have been preheated and calcined by a preheater 20 or the like, as described below, to a temperature of, for example, 1300°C or higher, causing a firing reaction to produce (fire) cement clinker. The rotary kiln 40 is cylindrical and installed extending horizontally. The rotary kiln 40 operates while rotating (rolling). The rotary kiln 40 is placed at a slight incline with respect to the installation surface (ground).

[0037] The rotary kiln 40 also has a kiln end 45 and a kiln front 41. A main burner (not shown) is provided in the kiln front 41 of the rotary kiln 40. The main burner injects pulverized coal into the kiln front 41 of the rotary kiln 40 to maintain the combustion reaction (combustion phenomenon). Furthermore, a kiln hood 42 is provided in the kiln front 41 of the rotary kiln 40. The kiln hood 42 is connected to a cooler device 43.

[0038] That is, in the rotary kiln 40, cement raw materials are burned at a predetermined temperature, and the burned cement clinker is transported from the kiln front section 41 to a cooler device 43, where it is cooled and discharged. The kiln rear section 45 is connected to the preheater 20, and preheated cement raw materials from the preheater 20 are supplied to the main body of the rotary kiln 40 through the kiln rear section 45.

[0039] In the rotary kiln 40 of this embodiment, the cement raw materials are fired to a maximum temperature of, for example, about 1,450°C, and then cooled in one go to about 125°C using the cooler described above. However, the temperature setting is not limited to this, and can be adaptively selected and set based on the properties of the cement raw materials or external environmental factors such as weather.

[0040] The preheater 20 introduces high-temperature exhaust gas discharged from the calciner 30, as described below, and preheats the cement raw materials being pulverized in a raw material mill (not shown), for example, to 800 to 900°C. The preheater 20 of this embodiment is a multi-stage cyclone type in which a plurality of cyclones 21 are connected in multiple stages in the vertical direction. A third exhaust duct DC3 is provided to connect the uppermost cyclone 21 and the second-highest cyclone 21. An inlet 22 for charging the cement raw materials is provided in the third exhaust duct DC3. A chute ST is provided between the lowermost cyclone 21 and the rotary kiln 40. The cement raw materials preheated by the preheater 20 are discharged through this chute ST. The cement raw materials pass through the rotary kiln 40 and are fed into the kiln end 45 of the rotary kiln 40. The fed cement raw materials are burned in the rotating rotary kiln 40 and ultimately become cement clinker. In this embodiment, the inlet 22 is disposed between the uppermost cyclone 21 and the second cyclone 21, but the present invention is not limited to this.

[0041] The calciner 30 receives high-temperature gas discharged from the rotary kiln 40 and also inputs fuel to calcinate the preheated cement raw materials. A plurality of sub-burners (not shown) and an inlet (not shown) are disposed at the bottom of the calciner 30. Each of the sub-burners injects pulverized coal into the interior of the calciner 30. Solid combustible waste, such as industrial waste, is input into the inlet of the calciner 30.

[0042] The calciner 30 also has a first exhaust duct DC1 (an example of an exhaust duct) and a second exhaust duct DC2. The first exhaust duct DC1 is erected vertically upward and connects and communicates with the lower end of the calciner 30 and the kiln end 45 of the rotary kiln 40. That is, the first exhaust duct DC1 is connected to the kiln end 45, and exhaust gas generated in the rotary kiln 40 flows through (is introduced into) the first exhaust duct DC1. The second exhaust duct DC2 connects and communicates with the upper end of the calciner 30 and the side wall of the lowest cyclone 21.

[0043] As described above, solid combustible waste and pulverized coal are combusted in the calciner 30. At the same time, exhaust gas generated in the rotary kiln 40 passes through the first exhaust duct DC1 and flows into the calciner 30. The exhaust gas flowing through the calciner 30 then passes from the upper end of the calciner 30 through the second exhaust duct DC2 and is introduced into the lowest cyclone 21.

[0044] In the treatment facility 10 configured in this manner, cement clinker is produced from cement raw materials as described above.

[0045] Specifically, cement raw materials (limestone, clay, silica, iron raw materials, etc.) are introduced into a raw material mill, optionally passing through a dryer. These cement raw materials are crushed in advance in the raw material mill and stored, for example, in a raw material mixing storage silo. Thereafter, as described above, they are preheated in the preheater 20, and a portion of them is calcined in the calciner 30, after which they are fed into the rotary kiln 40 for burning cement. The cement clinker is then burned in the rotary kiln 40 to become cement clinker, which is cooled in the cooler device 43 and then loaded into a clinker silo (not shown).

[0046] Regarding exhaust gas treatment, approximately half of the exhaust gas from the uppermost cyclone 21 of the preheater 20 is circulated (transferred) to the raw material mill. The remainder is transferred to the humidity control tower (not shown). The exhaust gas transferred to the raw material mill is used to dry the raw materials, and then passes through a dust collection cyclone (not shown) and is transferred to an electrostatic precipitator (not shown). Meanwhile, the exhaust gas transferred to the humidity control tower is cooled and its humidity adjusted by spraying it with industrial water stored in an industrial water storage tank. The exhaust gas from the raw material mill and the exhaust gas from the humidity control tower then merge just before the electrostatic precipitator, and the combined exhaust gases are mixed together and then dust collected by the electrostatic precipitator. The exhaust gas is then finally discharged to the outside through a chimney (not shown).

[0047] In this embodiment, a discharge pipe 55 of a supply unit 50 (described later) is provided at the kiln end 45 of a rotary kiln 40 of the treatment facility 10, and while cement clinker is produced as described above, an aqueous mixture AM containing PFOS and / or PFOA is simultaneously discharged from a discharge port 56 of the discharge pipe 55. This release effectively decomposes (destroys) these chemical substances. This is achieved safely and efficiently without producing any harmful substances (see below).

[0048] [Configuration of the supply unit 50] An example of the configuration of the supply unit 50 will be described with reference to FIGS. FIG. 2 is an enlarged view of the periphery of the kiln bottom portion 45 shown in FIG. FIG. 3 is an enlarged view of the main part of the discharge pipe 55 shown in FIG. 2, further enlarging the vicinity of the discharge port 56. In FIG.

[0049] As shown in FIGS. 2 and 3, the processing equipment 10 further includes a supply section 50 .

[0050] The supply section 50 is configured to have a storage tank 51, a pressure pump 52, and a discharge pipe 55, and releases an aqueous mixture AM containing PFOS and / or PFOA (hereinafter also referred to as the "aqueous mixture") into the inside of the kiln end section 45 of the rotary kiln 40.

[0051] In this embodiment, in order to destroy PFOS and / or PFOA, pretreatment is carried out by mixing these chemicals with a liquid such as water to form an aqueous mixture AM, or the PFOS and / or PFOA-containing liquid is received as industrial waste (for example, a foam fire extinguishing agent containing PFOS and PFOA). In this way, the treatment facility 10 of this embodiment treats the liquid state, i.e., the aqueous mixture AM containing PFOS and / or PFOA.

[0052] The storage tank 51 temporarily stores the aqueous mixture AM, for example, produced in pretreatment or transported from outside. The pressure pump 52 is disposed, for example, below the storage tank 51 and is connected to a discharge pipe 55 through a predetermined piping 53. The pressure pump 52 applies pressure to the aqueous mixture AM stored in the storage tank 51, and continuously sends (supplies) the aqueous mixture AM to the discharge pipe 55 through the piping 53.

[0053] The discharge pipe 55 is made of, for example, a metal pipe material and is bent at its middle. The discharge pipe 55 is attached (disposed) to the bottom 45 of the rotary kiln 40. Specifically, the discharge pipe 55 is disposed so as to penetrate the front and back of the wall of the bottom 45, which is located on the side opposite the main body of the rotary kiln 40 and on the first exhaust duct DC1 side, based on the intersection CP of the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the first direction DR1, which is the extension direction of the rotary kiln 40, and the second direction DR2, which is the extension direction of the first exhaust duct DC1. The bent tip of the discharge pipe 55 is disposed so as to face the entire interior of the bottom 45. The bent portion of the discharge pipe 55 is disposed close to the inner wall of the bottom 45.

[0054] For this reason, the discharge port 56 (tip opening) of the discharge pipe 55 is disposed so as to protrude toward the inside of the kiln end portion 45 of the rotary kiln 40, and the aqueous mixture AM is supplied from the pressure pump 52 and discharged from the discharge port 56 toward the inside of the kiln end portion 45. A spray nozzle (not shown) is attached to the discharge port 56 of the discharge pipe 55, and the discharge pipe 55 discharges the supplied aqueous mixture AM by spraying or spraying it in a conical radial pattern from the discharge port 56. The radiation angle is set to, for example, about 90°. In this embodiment, the concept of injection is understood to include the meaning of spray, and since the aqueous mixture AM is pumped by the pressure pump 52 as described above, it may be released in a mixed state of injection and spray.

[0055] Furthermore, in this embodiment, the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the intersection CP of the first direction DR1 and the second direction DR2 are used as references. In the internal space of the tail portion 45, the discharge port 56 of the discharge pipe 55 is disposed offset (displaced) toward the opposite side from the main body of the rotary kiln 40. In other words, the discharge port 56 is positioned so that the exhaust gas generated from the rotary kiln 40, which is changed in direction and flows in a curve to be introduced into the first exhaust duct DC1, is carried by the flow on the outside of the curve at the curved portion, and the aqueous mixture AM is discharged from the discharge port 56 (see below).

[0056] Furthermore, due to the bent portion of the discharge pipe 55, the central axis of the discharge direction of the discharge port 56 is inclined upward so as to face the main body of the first exhaust duct DC1. The inclination angle A is set in the range of 30° to 60°, more preferably 45°, with respect to the horizontal direction (see FIG. 3).

[0057] [About the decomposition process] Referring again to FIG. 3, the process of decomposing PFOS and / or PFOA in this embodiment will be described. FIG. 3 is an enlarged view of the main part of the discharge pipe 55 shown in FIG. 2, further enlarging the vicinity of the discharge port 56. In FIG.

[0058] As described above, the treatment equipment 10 of this embodiment is normally operated as cement clinker burning equipment, and a preheater 20 is connected to the top of the kiln end 45 of the rotary kiln 40, and the cement raw materials pulverized in a raw material mill are preheated by this preheater 20. The preheated cement raw materials are then dropped into the kiln end 45 of the rotary kiln 40 and burned in the rotary kiln 40. As a result, cement clinker is generated (manufactured). In other words, the treatment equipment 10 of this embodiment produces cement clinker in the normal manner as cement clinker burning equipment.

[0059] 3, during the firing process in the rotary kiln 40, exhaust gas is generated in the rotary kiln 40 as a result of the firing, and at least a portion of the exhaust gas passes through the kiln end section 45 and is introduced into the first exhaust duct DC1. In other words, at least a portion of the exhaust gas from the rotary kiln 40 curves and changes direction vertically upward at the kiln end section 45, and flows (is introduced) into the first exhaust duct DC1.

[0060] As described above, the discharge pipe 55 of the supply unit 50 is disposed with its discharge port 56 protruding into the kiln end section 45. Specifically, the discharge port 56 is disposed offset (displaced) from the main body of the rotary kiln 40 in the internal space of the kiln end section 45, based on the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the intersection CP of the first direction DR1 and the second direction DR2. Furthermore, the central axis of the discharge direction of the discharge port 56 is set to be inclined upward so as to face the main body of the first exhaust duct DC1 (see symbol A in FIG. 3).

[0061] Furthermore, at the curved portion of the flow of exhaust gas in the internal space of the kiln bottom section 45, the flow velocity on the outside of the curved portion is higher than the flow velocity on the inside of the curved portion. Therefore, in this embodiment, the aqueous mixture AM discharged from the discharge port 56 rides on the flow on the outside of the curved portion of the exhaust gas and flows vigorously toward the first exhaust duct DC1. While riding on this fast flow toward the first exhaust duct DC1, the aqueous mixture AM is incinerated at high temperatures by the combustion energy in the rotary kiln 40 and the calciner 30.

[0062] As a result, the PFOS and / or PFOA contained in the aqueous mixture AM are decomposed (destroyed) without generating harmful substances, etc. Furthermore, in this embodiment, the release direction is set on the opposite side of the rotary kiln 40, Therefore, it is possible to suppress the cooling of the operating temperature of the rotary kiln 40, burn cement clinker as in normal operation, and efficiently decompose PFOS and / or PFOA.

[0063] [Features and advantages of this embodiment] As described above, the treatment equipment 10 of this embodiment includes a preheater 20 that preheats the cement raw materials ground in a raw material mill, a rotary kiln 40 (an example of a kiln) connected to the bottom end 45 of the preheater 20 and that produces clinker by burning the cement raw materials preheated by the preheater 20, and a discharge pipe 55 that is disposed in the bottom end 45 and has a discharge port 56 that protrudes toward the inside of the bottom end 45, and through which an aqueous mixture AM containing PFOS and / or PFOA is supplied and released from the discharge port 56 toward the inside of the bottom end 45. Furthermore, while clinker is being produced, the aqueous mixture AM is simultaneously released from the discharge port 56 of the discharge pipe 55.

[0064] The treatment method of this embodiment also includes the following steps: a preheating step of using a preheater 20 to preheat the cement raw materials pulverized in a raw material mill; a firing step of using a rotary kiln 40 (an example of a kiln) connected to the bottom end 45 of the preheater 20 to fire the cement raw materials preheated by the preheater 20 to produce clinker; and a discharging step of using a discharge pipe 55 disposed in the bottom end 45 and having a discharge port 56 protruding toward the inside of the bottom end 45 to supply an aqueous mixture AM containing PFOS and / or PFOA to the discharge pipe 55 and discharge the aqueous mixture AM from the discharge port 56 toward the inside of the bottom end 45. The preheating step, the firing step, and the discharging step are performed in parallel.

[0065] Therefore, by utilizing (reusing) the treatment facility 10 that has been in operation for cement production, the chemical substances PFOS and / or PFOA can be decomposed (destroyed) without generating harmful substances during the treatment process. Furthermore, since PFOS and / or PFOA are decomposed simultaneously while cement is being produced, treatment can be carried out economically and efficiently. Furthermore, large quantities of PFOS and / or PFOA can be treated.

[0066] According to the processing equipment 10 of this embodiment, a first exhaust duct DC1 (an example of an exhaust duct) is connected to the kiln end 45, and is installed vertically upward. The first exhaust duct DC1 carries exhaust gas generated in the rotary kiln 40 (an example of a kiln). A discharge pipe 55 is disposed on the wall surface of the kiln end 45, located on the side of the first exhaust duct DC1, opposite the main body of the rotary kiln 40, based on the intersection CP of the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the first direction DR1, which is the extension direction of the rotary kiln 40, and the second direction DR2, which is the extension direction of the first exhaust duct DC1.

[0067] Therefore, the released aqueous mixture AM is incinerated by riding on the fast-flowing outer exhaust gas flow, so that destruction is reliably carried out during the decomposition (destruction) process, thereby suppressing the generation of harmful substances. Also, because the aqueous mixture AM does not flow toward the rotary kiln 40 (an example of a kiln), a decrease in the operating temperature of the rotary kiln 40 can be suppressed.

[0068] Furthermore, according to the processing equipment 10 of this embodiment, a first exhaust duct DC1 (an example of an exhaust duct) that is installed vertically upward is connected to the kiln bottom section 45. Further, exhaust gas generated in the rotary kiln 40 (an example of a kiln) flows through the first exhaust duct DC1. Further, the discharge port 56 is connected to the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the first direction DR1, which is the extension direction of the rotary kiln 40, and the first exhaust duct DC1. The rotary kiln 40 is disposed in the internal space of the kiln bottom portion 45, offset toward the opposite side of the main body portion of the rotary kiln 40, based on the intersection point CP of the second direction DR2, which is the extension direction of the cut DC1.

[0069] Therefore, the released aqueous mixture AM is treated by riding on the fast-flowing outer exhaust gas, so that destruction is reliably carried out during the decomposition (destruction) process, thereby suppressing the generation of harmful substances. Also, because the aqueous mixture AM does not flow toward the rotary kiln 40 (an example of a kiln), a decrease in the operating temperature of the rotary kiln 40 can be suppressed.

[0070] Furthermore, according to the processing equipment 10 of this embodiment, the central axis of the discharge direction of the outlet 56 is set to be inclined upward so as to face the main body side of the first exhaust duct DC1 (an example of an exhaust duct).

[0071] This allows the exhaust gas from the rotary kiln 40 (an example of a kiln) to flow through the exhaust gas and minimizes contact with the cement raw materials, thereby minimizing the impact on cement production and reducing the operating temperature of the rotary kiln 40.

[0072] Furthermore, according to the treatment facility 10 of this embodiment, the discharge pipe 55 discharges the aqueous mixture AM radially from the discharge port 56 .

[0073] This allows for suppressing cooling of the operating temperature of the rotary kiln 40 (an example of a kiln), thereby increasing the efficiency of the decomposition (destruction) of PFOS and / or PFOA while minimizing the operational impact on cement production.

[0074] Furthermore, the treatment equipment 10 of this embodiment may further include a storage tank 51 for storing the aqueous mixture AM, and a pressure pump 52 connected to the discharge pipe 55 for pressure-feeding and supplying the aqueous mixture AM from the storage tank 51.

[0075] In this case, the aqueous mixture AM can be continuously supplied to the kiln end 45 of the rotary kiln 40 (an example of a kiln) efficiently, thereby enabling decomposition (destruction) of a larger amount of PFOS and / or PFOA.

[0076] Furthermore, according to the treatment facility 10 of this embodiment, the pressure pump 52 continuously supplies the aqueous mixture AM to the discharge pipe 55 .

[0077] Therefore, the aqueous mixture AM is continuously supplied toward the inside of the kiln end portion 45, thereby suppressing the accompanying fluctuations in the temperature load of the equipment and maintaining stable operation of the rotary kiln 40 (an example of a kiln).

[0078] [First Modification of the Present Embodiment] In this modification, the discharge pipe 55 is disposed at the lower end of the first exhaust duct DC1 (an example of an exhaust duct) rather than at the kiln bottom section 45. The discharge port 56 is disposed so as to protrude toward the inside of the first exhaust duct DC1, and the aqueous mixture AM containing PFOS and / or PFOA is supplied and discharged from the discharge port 56 toward the inside of the first exhaust duct DC1. In this case, the same effects as those of this embodiment are achieved. [Example]

[0079] The usefulness of the present invention will be explained in more detail by providing one or more tests as examples (application examples and / or specific examples) of the present invention.

[0080] <First Example> In order to confirm the usefulness of the present invention, a confirmation test was conducted using a PFOS- and PFOA-containing foam fire extinguishing agent (hereinafter also referred to as the "test sample") as an aqueous mixture (AM) containing PFOA and PFOS. The details of the confirmation test are shown below.

[0081] [Test method] While cement clinker is being burned using equipment already installed and operating as cement clinker burning equipment (test equipment), an aqueous mixture of PFOA and PFOS (AM: foam fire extinguishing agent in this example) is released (discharged) from the kiln end (45) of the rotary kiln (40). A test is conducted to incinerate these chemicals by this discharge.

[0082] Samples are then taken from multiple locations in the test facility (see "Sample Collection Locations" below) and evaluated.

[0083] For the evaluation, test samples, solid samples, and exhaust gas samples obtained from each collection site will be pretreated in accordance with the "Technical Considerations for the Treatment of PFOS- and PFOA-Containing Waste" (September 2022, Waste Control Division, Environmental Regeneration and Resource Recycling Bureau, Ministry of the Environment; hereinafter referred to as the "Guidelines"), and then analyzed for identification and quantification using a liquid chromatograph mass spectrometer (LC-MS / MS).

[0084] Through this analysis, the efficiency of PFOS decomposition and removal, the emission concentration of PFOS, and the emission concentration of PFOA will be evaluated. Management target values ​​will be set based on the aforementioned guidelines. In this example, the presence or absence of generation of harmful substances such as hydrogen fluoride and dioxins is also evaluated as appropriate.

[0085] In addition, the PFOS- and PFOA-containing foam fire extinguishing agent has a very high viscosity, which may make it difficult to discharge (spray or spray) from the spray nozzle of the discharge outlet (56) in its original state. Therefore, in order to facilitate its discharge into the kiln end (45), the PFOS- and PFOA-containing foam fire extinguishing agent is diluted before being discharged.

[0086] [Testing equipment] The cement clinker burning equipment configured as described above was used as the test equipment. The main specifications of the test equipment are shown in Table 1. The installation location is in northern Okinawa Prefecture.

[0087] [Table 1]

[0088] [Target to be treated (test sample)] In this example, a foam fire extinguishing agent containing PFOS and PFOA (PFOS concentration: approximately 6,000 mg / kg, PFOA concentration: approximately 60 mg / kg) is used as the test sample. The amount of PFOS added is set to 1,000 g / h (5,000 g / 5 h) taking into account the analytical lower limit of quantitative analysis.

[0089] [Sample collection location] (Storage tank: test sample) Test samples are taken directly before being put into the test equipment for comparison before and after treatment. Specifically, they are taken from the storage location before being put into the test equipment, i.e., the storage tank (51). As mentioned above, the test samples are diluted to make them easier to release into the kiln bottom (45). Therefore, the diluted samples are taken as test samples and evaluated. (Rotary kiln: cement clinker) Considering the residence time in the rotary kiln (40) (about 40 minutes) and the cooling time in the cooler unit (43) (about 20 minutes), samples are taken one hour after the start of the test sample introduction, and then four times at one-hour intervals at the outlet of the cooler unit (43). (Dust: Electrostatic dust collection ash) Considering the residence time from the rotary kiln (40) to the preheater (20) (it is assumed that the time it takes for the exhaust gas to reach the electrostatic precipitator is about 10 to 15 minutes), the test sample is taken once one hour after the start of feeding the test sample, and then a total of four times at one-hour intervals on the conveyor at the soot and dust outlet (56) from the electrostatic precipitator. (Raw material storage silo: cement raw materials) Taking into account the residence time from the preheater (20) to the rotary kiln (40) (it is assumed that it takes about two hours for the electrostatically collected ash to mix with the cement raw materials), the test sample is taken once two hours after the start of the test sample introduction, and then a total of four times at one-hour intervals at the outlet of the raw material storage silo. (Above the preheater: exhaust gas) Taking into account the residence time from the rotary kiln (40) to the top of the preheater (20), samples are collected continuously for four hours for dioxin measurement, starting one hour after the test samples are first introduced. Two one-hour continuous samples are collected for each of PFOS and PFOA. (Chimney: Exhaust gas) Taking into account the residence time of the exhaust gas from the rotary kiln (40) to the chimney, samples are collected continuously for four hours for dioxin measurement, starting one hour after the test samples are first introduced. Two one-hour continuous samples are collected for each of PFOS and PFOA. (Industrial water: water) Collect from the outlet of an industrial water storage tank.

[0090] [Test Results] Samples were collected from each of the collection locations and analyzed and evaluated based on the aforementioned guidelines. The results of the evaluation are summarized below.

[0091] (1) Both the decomposition efficiency and decomposition and removal efficiency of PFOS achieved the target values. (2) PFOS emission concentrations in exhaust gas, cement clinker, and soot and dust were below the control target values. (3) The hydrogen fluoride emission concentration was evaluated to be below the control target value of 5 mg / m3N. (4) The concentration of dioxins in the smokestack exhaust gas was below the emission standard of 0.1ng-TEQ / m3N, as stipulated by the Law Concerning Special Measures against Dioxins. (5) PFOA decomposition efficiency and decomposition and removal efficiency For PFOA, the degradation and removal efficiencies were 99.9947% and 99.9986%, respectively. (6) Evaluation of PFOA emission concentration PFOA emission concentrations in exhaust gas, cement clinker, and particulate matter were below the management target values.

[0092] As described above, this example demonstrates that PFOS and PFOA can be decomposed (destroyed) in large quantities without generating harmful substances during the treatment process by utilizing (reusing) treatment equipment (10) that has been in operation for cement production. The usefulness of the present invention was confirmed through this example (this confirmation test).

[0093] <Conclusion> This concludes the description of one or more specific embodiments and one or more specific examples, but the aspects of the present invention are not limited to these embodiments or examples, and modifications, improvements, etc. are possible as appropriate. [Industrial Applicability]

[0094] The present invention is useful as a treatment facility and treatment method that can decompose (destroy) PFOS and / or PFOA in large quantities without generating harmful substances during the treatment process, by utilizing (reusing) treatment facilities that have been in operation for some time in cement production. [Explanation of symbols]

[0095] 10: Processing equipment 20: Preheater 21: Cyclone 22: Inlet 30: Calciner 40: Rotary kiln 41: Front of the kiln 42: Kiln Hood Section 43: Cooling device 45: Bottom of the kiln 50: Supply section 51: Storage tank 52: Pressure pump 53: Piping 55:Discharge pipe 56:Discharge port AM: Aqueous mixture CP: intersection DC1: First exhaust duct DC2: Second exhaust duct DC3: Third exhaust duct DR1: First direction DR2: Second direction ST: Shoot

Claims

1. A method of manufacturing a cement mill, comprising: a preheating step of preheating cement raw materials pulverized in a raw material mill using a preheater; a firing step of firing the cement raw materials preheated by the preheater using a kiln having a kiln bottom part and the preheater connected to the kiln bottom part to produce clinker; a discharge step of supplying an aqueous mixture containing PFOS and / or PFOA to a discharge pipe having a discharge port disposed in the kiln bottom section, the discharge port protruding toward the inside of the kiln bottom section, and discharging the aqueous mixture from the discharge port toward the inside of the kiln bottom section, An exhaust duct standing vertically upward is connected to the kiln buttock, The exhaust duct allows exhaust gas generated in the kiln to flow through, The discharge pipe is disposed on the wall surface of the kiln bottom portion, which is opposite to the main body of the kiln and located on the exhaust duct side, based on the intersection of the main body of the kiln, the main body of the exhaust duct, and a first direction which is the extension direction of the kiln and a second direction which is the extension direction of the exhaust duct, In the discharge step, the aqueous mixture is supplied in a liquid state to the discharge pipe and discharged from the discharge port, The preheating step, the baking step, and the ejection step are carried out in parallel, Thereby, the PFOS and / or PFOA contained in the aqueous mixture are destroyed while the clinker is produced. Processing method.

2. A method of manufacturing a cement mill, comprising: a preheating step of preheating the cement raw material pulverized in a raw material mill using a preheater; a firing step of firing the cement raw materials preheated by the preheater using a kiln having a kiln bottom part and the preheater connected to the kiln bottom part to produce clinker; a discharge step of supplying an aqueous mixture containing PFOS and / or PFOA to a discharge pipe having a discharge port disposed in the kiln bottom section, the discharge port protruding toward the inside of the kiln bottom section, and discharging the aqueous mixture from the discharge port toward the inside of the kiln bottom section, An exhaust duct standing vertically upward is connected to the kiln buttock, The exhaust duct allows exhaust gas generated in the kiln to flow through, The discharge port is offset toward the opposite side of the main body of the kiln in the internal space of the kiln buttocks, based on the main body of the kiln, the main body of the exhaust duct, and the intersection of the first direction which is the extension direction of the kiln and the second direction which is the extension direction of the exhaust duct. In the discharge step, the aqueous mixture is supplied in a liquid state to the discharge pipe and discharged from the discharge port, The preheating step, the baking step, and the ejection step are carried out in parallel, Thereby, the PFOS and / or PFOA contained in the aqueous mixture are destroyed while the clinker is produced. Processing method.

3. a central axis of the outlet port in the discharge direction is set to be inclined upward so as to face the main body side of the exhaust duct; The processing method according to claim 2 .

4. The discharge pipe radially discharges the aqueous mixture from the discharge port. The processing method according to claim 3.

5. a storage tank for storing the aqueous mixture; a pressure pump connected to the discharge pipe for pressure-feeding and supplying the aqueous mixture in the storage tank; 3. The processing method according to claim 1 or 2.

6. the pressure pump continuously supplies the aqueous mixture to the discharge pipe; The processing method according to claim 5.

7. a preheating step of preheating the cement raw material pulverized in the raw material mill using a preheater; a firing step of firing the cement raw materials preheated by the preheater using a kiln having a kiln bottom part and the preheater connected to the kiln bottom part to produce clinker; a discharge step of supplying an aqueous mixture containing PFOS and / or PFOA to a discharge pipe having a discharge outlet, the discharge pipe having a discharge outlet projecting toward the inside of the exhaust duct, and discharging the aqueous mixture from the discharge outlet toward the inside of the exhaust duct, The aqueous mixture is supplied in a liquid state to the discharge pipe and discharged from the discharge port; The preheating step, the baking step, and the ejection step are carried out in parallel, Thereby, the PFOS and / or PFOA contained in the aqueous mixture are destroyed while the clinker is produced. Processing method.

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