Method for treating silicone oil

Abstract

To provide a silicone oil processing method capable of reducing time and cost required for disposal of silicone oil.SOLUTION: The silicone oil processing method includes an adsorption step of adsorbing silicone oil into granules formed with non-combustible porous material. The granules may be formed of porous ceramic material and / or diatomaceous earth may be included. The silicone oil processing method includes a step of putting granules and silicone oil into a container 1. In the adsorption step, the granules and silicone oil placed in the container 1 may be stirred.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for treating silicone oil.

Background Art

[0002] Facilities and equipment using silicone oil are installed within the regulated area of nuclear power plants, and silicone oil is regularly discharged. As a waste treatment for waste oil, incineration treatment that can reduce the volume of waste is common, so it is conceivable to perform the same incineration treatment for silicone oil. For example, Patent Document 1 discloses a treatment method in which gas generated by incinerating silicone oil is filtered through a ceramic filter, and incineration ash of silicone oil is recovered from the ceramic filter and discarded as pellet-shaped waste.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the treatment method of Patent Document 1, a large amount of fine particles of silicon dioxide (SiO2) are generated by incinerating silicone oil, so frequent replacement of the ceramic filter is required. The ceramic filter is expensive, and since the fine particles derived from the silicone oil discharged from within the regulated area of the nuclear power plant adsorb to it, it is also necessary to handle the waste as radioactive waste, so there are cost problems for frequent replacement. Due to such a background, in reality, silicone oil is stored as a liquid as before at the site. However, even when storing silicone oil as a liquid, problems such as the need to newly install a dedicated storage facility and notify relevant agencies as the storage volume increases cannot be solved.

[0005] The present invention has been made based on such a background, and an object thereof is to provide a method for treating silicone oil that can reduce the labor and cost required for disposing of silicone oil.

Means for Solving the Problems

[0006] In order to achieve the above object, the method for treating silicone oil according to the present invention includes: A charging step of charging granular materials formed of a non-combustible porous material and silicone oil into a container; An adsorption step of adsorbing the silicone oil onto the granular materials such that when the granular materials come into contact with other objects, the silicone oil does not adhere to the other objects, by stirring the granular materials and the silicone oil in the container while an operator touches the granular materials and the silicone oil by hand with gloves on; including.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a method for treating silicone oil that can reduce the labor and cost required for disposing of silicone oil.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the method for treating silicone oil according to an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals.

[0010] The method for treating silicone oil according to the embodiment is a method of stably solidifying silicone oil by adsorbing silicone oil onto a large number of granular bodies formed of a non-combustible adsorbent that adsorbs silicone oil. Specifically, as shown in FIG. 1, silicone oil and a large number of granular bodies are put into the container 1, and the two are stirred in the container 1 to adsorb the silicone oil onto the granular bodies. As a result, the silicone oil can be solidified to such an extent that it does not fall under the designated combustibles specified in the Cabinet Order regarding the regulation of dangerous goods.

[0011] As methods for solidifying silicone oil, a method of solidifying silicone oil using a coagulant and a method of impregnating an object that absorbs a liquid, such as a cloth or a sponge, with silicone oil can be considered. However, in any of these methods, the silicone oil gradually oozes out to the surface over time, so it falls under the designated combustibles specified in the Cabinet Order regarding the regulation of dangerous goods. On the other hand, in the method for treating silicone oil according to the embodiment, the silicone oil once adsorbed onto the granular bodies does not ooze out to the surface of the granular bodies, and even from the calorific value of combustion of the non-combustible granular bodies that have adsorbed the silicone oil, it does not fall under the designated combustibles specified in the Cabinet Order regarding the regulation of dangerous goods.

[0012] The adsorbent according to the embodiment is formed of a porous material having a large number of micropores. The porous material is, for example, a porous ceramic material formed of a ceramic material. The average diameter of the micropores is set to such an extent that the silicone oil can be confined by surface tension. Specifically, the average diameter (diameter) of the micropores is, for example, 10 μm or less, preferably 1 μm or less, and more preferably 0.3 μm or less.

[0013] As raw materials for the adsorbent according to the embodiment, for example, diatomaceous earth, clay, zeolite, zirconia, and alumina can be used, but it is preferable to use diatomaceous earth. Diatomaceous earth is a sediment containing fossils of diatom shells and contains silicon dioxide as a main component. Various additives, for example, sodium carbonate, may be added to the raw material of the adsorbent. The granular body according to the embodiment may have an arbitrary shape, but is preferably spherical or cylindrical, for example. As an example, the granular body according to the embodiment is cylindrical and formed within a range of a diameter of 0.5 mm to 2 mm and a length of 1 to 3 mm.

[0014] The granular body according to the embodiment is produced, for example, by pulverizing diatomaceous earth as a raw material into a powder using a pulverizer, adding water to the pulverized diatomaceous earth and kneading it, forming the kneaded product, and then firing it at a high temperature. By firing the formed body at a high temperature, impurities contained therein can be removed. In the kneading step, additives may be added as necessary. In the forming step, for example, it may be formed into a cylindrical shape using an extrusion molding machine.

[0015] The granular body according to the embodiment can confine silicone oil inside the micropores due to the action of surface tension and hold it stably. Therefore, it remains dry after adsorbing silicone oil. The dry state means that silicone oil does not ooze out from the surface after adsorbing silicone oil and does not adhere to other objects even when it comes into contact with other objects. In the dry state, oxygen cannot contact the silicone oil confined in the micropores. Therefore, sufficient flame retardancy can be obtained even though the silicone oil is adsorbed.

[0016] Next, with reference to FIG. 2, the flow of the method for treating silicone oil according to the embodiment will be described. First, the silicon oil to be discarded, which is contained in the can 2, is put into the container 1 (step S1). At this time, it is preferable to confirm that the temperature of the silicon oil is at or above the pour point. This is because when the temperature of the silicon oil is below the pour point, its fluidity decreases, and there is a possibility that the silicon oil will not be adsorbed by the granular material in the process described later. If the temperature of the silicon oil is below the pour point, the silicon oil may be appropriately heated in the state of being contained in the can 2 before the silicon oil is put in.

[0017] Next, a large number of granular materials are put into the container 1 into which the silicon oil has been put in the step of step S1 (step S2). As the granular material, what is packed in the bag 3 may be directly put into the container 1.

[0018] Next, the silicon oil and the large number of granular materials are stirred in the container 1 to adsorb the silicon oil onto the granular materials (step S3). This stirring may be performed manually, for example, by an operator wearing gloves. In this step, the silicon oil is repeatedly brought into contact with the entire surface of the granular material to quickly and surely adsorb the silicon oil onto the granular material, and it is confirmed by the feel of the granular material that the adsorption of the silicon oil is completed.

[0019] Next, the granular materials that have adsorbed the silicon oil in the step of step S3 are recovered from the container 1 (step S4). The granular materials that have adsorbed the silicon oil may be returned to the bag 3 in which the granular materials before adsorption were packed. The bag 3 packed with the granular materials that have adsorbed the silicon oil may be carried into, for example, a solid waste storage of a nuclear power plant and stored together with other solid wastes. The above is the flow of the method for treating silicon oil.

[0020] The method for treating silicone oil according to the embodiment has the following advantages compared with the case of storing liquid silicone oil. First, to store liquid silicone oil, a dedicated storage facility different from a solid waste storage facility is required. However, in the method for treating silicone oil according to the embodiment, the granular material adsorbed with silicone oil can be stored in an existing solid waste storage facility. Also, to store a certain amount or more of liquid silicone oil, notification to the fire department is required. However, in the method for treating silicone oil according to the embodiment, since the granular material adsorbed with silicone oil does not fall under the designated combustibles specified in the Cabinet Order regarding the regulation of dangerous goods, notification to the fire department is not required even when storing a certain amount or more. And the granular material adsorbed with silicone oil can be discarded as solid waste in the same procedure as other solid waste.

[0021] As described above, the method for treating silicone oil according to the embodiment includes a step of adsorbing silicone oil onto a granular material formed of a non-combustible porous material. For this reason, it can be solidified by a simple method compared to other treatment methods such as incineration treatment, and can be stored in a solid waste storage facility in the same manner as other solid waste. Also, the granular material formed of a non-combustible porous material can be obtained at low cost. As a result, the labor and cost required for discarding silicone oil discharged from within the management area of a nuclear power plant can be suppressed more than before.

[0022] The present invention is not limited to the above embodiment, and the following modifications are also possible.

[0023] (Modification example) In the above embodiment, after the silicone oil was put into container 1, the adsorbent was put into container 1. However, the present invention is not limited to this. Conversely, after the adsorbent is put into container 1, the silicone oil may be put into container 1.

[0024] In the above-described embodiment, the charging and stirring of the adsorbent and silicone oil were performed manually, but the present invention is not limited thereto. The charging of the adsorbent and silicone oil may be performed manually, and the adsorbent and silicone oil may be stirred using a stirrer. The stirrer may include, for example, a stirring blade capable of stirring an object by rotating, and may be manually held so that the stirring blade contacts the adsorbent and silicone oil in the container 1.

[0025] Further, for the treatment of the adsorbent and silicone oil, a treatment device for charging and stirring the adsorbent and silicone oil may be used. The treatment device is, for example, installed above the container 1, and in response to a user's instruction, the adsorbent and silicone oil accommodated therein are charged into the container 1, and then, the adsorbent and silicone oil charged into the container 1 are stirred by a stirring blade capable of stirring an object by rotating.

[0026] In the above-described embodiment, the production process of the granular material included pulverizing, kneading, molding, and firing of diatomaceous earth, but the present invention is not limited thereto. For example, when the purity of diatomaceous earth is high, diatomaceous earth may be pulverized into granules using a pulverizer, and the granular material may be dried to produce the granular material. The drying of the granular material may be, for example, natural drying or high-temperature drying.

[0027] In the above-described embodiment, the solidification of silicone oil discharged from within the controlled area of a nuclear power plant was carried out, but the present invention is not limited thereto. The treatment method of the above-described embodiment is not limited to the controlled area of a nuclear power plant, and may be applied to the treatment of silicone oil discharged at other locations.

[0028] The above-described embodiments are illustrative, and the present invention is not limited thereto. Various embodiments are possible without departing from the spirit of the invention described in the claims. The constituent elements described in the embodiments and modification examples can be freely combined. Also, inventions equivalent to the invention described in the claims are included in the present invention.

[0029] Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

[0030] (Example) In the example, the disposal of the liquid silicon oil stored in the power plant was carried out. The silicon oil to be treated was used silicon oil distributed and stored in 20L cans.

[0031] The following is a description of the specific procedure of the treatment operation. First, the silicon oil stored in the 20L can was put into a working container, and then a total of 30 kg (60L) of granular adsorbent was put into the working container. The capacity of the working container is 170L. As the granular adsorbent, a commercially available road surface oil treatment material manufactured by pulverizing diatomaceous earth into powder, forming it, and firing it at high temperature was used. Next, the granular material and the silicon oil were manually stirred in the working container. As a result, the silicon oil could be easily adsorbed onto the granular material only by manual stirring by the operator. The granular material adsorbed with silicon oil was in a dry state as shown in Fig. 3(a), and no silicon oil adhered to the operator's gloves after the work.

[0032] Next, the granular material adsorbed with silicon oil was put back into the bag in which the granular material was originally stored, and it was observed for a long time whether the silicon oil would ooze out from the granular material. As a result, as shown in Fig. 3(b), the silicon oil did not ooze out from the granular material adsorbed with silicon oil, and no silicon oil adhered to the bag.

[0033] After that, when it was proved by the test results that the granular material adsorbed with silicon oil did not fall under the designated combustibles in terms of the calorific value of combustion, it was possible to obtain an opinion from the fire department that the granular material adsorbed with silicon oil did not fall under the designated combustibles defined in the ordinance regarding the regulation of dangerous goods.

Explanation of symbols

[0034] 1 Container 2 Can 3 Bag

Claims

1. An input step of inputting granular materials formed of a non-combustible porous material and silicone oil into a container; An adsorption step of adsorbing the silicone oil onto the granular materials such that when the granular materials come into contact with other objects, the silicone oil does not adhere to the other objects, by stirring the granular materials and the silicone oil in the container while an operator touches the granular materials and the silicone oil by hand with gloves on; A method for treating silicone oil, comprising the above steps.

2. The silicone oil is discharged from within the controlled area of a nuclear power plant. The method for treating silicone oil according to Claim 1.

3. The granular materials are formed of a porous ceramic material. The method for treating silicone oil according to Claim 1 or 2.

4. The granular materials contain diatomaceous earth. The method for treating silicone oil according to Claim 3. ​ ​ ​ ​ ​

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