JPH0139008B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for incinerating waste ion exchange resin. More specifically, the present invention relates to a method in which wet coarse waste ion exchange resin taken out from an ion exchange treatment process can be directly incinerated as it is. In the nuclear power field, etc., the amount of wet coarse waste ion exchange resin extracted from the ion exchange treatment process has increased significantly, and the establishment of technology to reduce its volume has become an issue. Incineration of waste ion exchange resin has been considered, but even if conventional methods such as rotary kiln, multi-stage furnace, fluidized bed furnace, and stirred hearth method are used for incineration, combustion will not occur. These methods have been difficult to adopt because they have low efficiency and require a large amount of combustion air, making the exhaust gas treatment equipment extremely large. Furthermore, even if incineration treatment is attempted using other methods such as pulverized coal combustion, the wet coarse waste ion exchange resin must be pulverized to less than 200 mesh as a pretreatment and dried to a specified level. This method was difficult to adopt because it required complex equipment and advanced technical measures to prevent dust explosions. The present invention was invented in view of these conventional problems, and its purpose is to incinerate the wet coarse waste ion exchange resin taken out from the ion exchange treatment process, that is, to pulverize it. To provide a method for incinerating waste ion exchange resin, which can efficiently incinerate the resin without any pretreatment such as drying or drying, and can further reduce the amount of exhaust gas. The waste ion exchange resin incineration treatment method according to the present invention achieves this objective by mixing the moistened coarse waste ion exchange resin with fuel oil and water in the presence of a milking agent to form an oil-in-water three-component system. It is characterized by forming a stable emulsion and then spraying and combusting this either alone or under auxiliary combustion. The waste ion exchange resin taken out from the ion exchange treatment process is a coarse resin and is wet, and it is difficult to obtain a stable homogeneous dispersion even if it is mixed with fuel oil or water alone. In the present invention, since the waste ion exchange resin is mixed with fuel oil and water in the presence of an emulsifier, an extremely stable oil-in-water emulsion having a three-component system of waste ion exchange resin, fuel oil, and water can be obtained. Note that a water-in-oil emulsion can also be obtained by mixing the waste ion exchange resin with fuel oil and water in the presence of a water-in-oil emulsifier; difficult to achieve. This is because when the amount of water in this type of emulsion increases relative to the fuel oil, the fluidity at room temperature deteriorates, making it difficult to pump the liquid. This is because the fluidity deteriorates as the weight ratio of the liquid (a mixture of water and water) increases. In the present invention, the composition range of the oil-in-water emulsion is not particularly limited; It is preferable that the weight ratio with respect to the mixed liquid is 20:80 to 70:30. Table 1 shows examples of oil-in-water emulsions having various composition ranges. In addition, (A) to (F), (O/
W) and (R/L) represent the following, and in the row of "emulsion stability", the (○) symbol indicates good, the (△) symbol indicates separation within 1 hour, and the (x) symbol indicates separation. Separation within a few minutes is shown in each case, and in the "room temperature fluidity" row, the (◯) symbol indicates good and the (△) symbol indicates poor. In this example, an oil-in-water type nonionic emulsifier is used. (A): Wetted waste cation exchange resin (Powdex PCH manufactured by Organo Co., Ltd.) with 60 to 400 meshes and a porosity of 7.6%. (B): Wetted waste anion exchange resin (Powdex PAO manufactured by Organo Co., Ltd.) with 60 to 400 meshes and a porosity of 31%. (C): Wetted waste cation exchange resin (Amberlite 1R120B manufactured by Organo Co., Ltd.) with an effective diameter of 0.45 to 0.60 mm and a porosity of 35%. (D): Wetted waste anion exchange resin (Amberlite 1RA40O manufactured by Organo Co., Ltd.) with an effective diameter of 0.45 to 0.60 mm and a porosity of 35%. (E): A mixture of the above (A) and (B), wherein the above (A) and (B)
The weight ratio is 3:1. (F): A mixture of the above (A) to (D), which includes the above (A) and (B).
The weight ratio of (C) and (D) is 6:2:2:1. (O/W): Weight ratio of fuel oil and water. (R/L): Weight ratio of each of the waste ion exchange resins (A) to (F) above and the mixed liquid (liquid mixed with fuel oil and water).

【table】

[Table] As described above, in the present invention, various composition ranges can be provided for the oil-in-water emulsion, but it is not very preferable to provide the composition ranges as in Examples 7 and 9. In other words, as in Example 7, (O/W) is changed to (16/
84), even if the emulsion stability and room-temperature fluidity are good, the flame stability will be insufficient even if it is burned under auxiliary combustion, and as in Example 9. If (O/W) is set to (85/15), the fluidity will deteriorate and the liquid feeding operation will become difficult, which is not very preferable. Regarding (O/W), generally at least (10/
90) or above, a stable emulsion can be obtained, and in this case, the oil droplets will be from several microns to several tens of microns in size and will be dispersed densely in the water, preventing the resin particles from settling. In order to obtain a stable flame during combustion, it is preferable to provide a ratio of (20/80) or more even under auxiliary combustion. In addition, (R/L) is preferably less than (70/30) because if it is too large, the fluidity will deteriorate and the liquid feeding operation will be difficult. Next, Table 2 shows water-in-oil emulsions having various composition ranges. In addition, (A) in this table
(F), (O/W), (R/L), and other various symbols are shown in Table 1.
The emulsifier used is a water-in-oil type nonionic emulsifier.

[Table] As is clear from this, the fluidity of the water-in-oil emulsion is significantly inferior to that of the oil-in-water emulsion shown in Table 1, and (R/
It can be seen that the water-in-oil emulsion cannot achieve the object of the present invention more fully because the amount of fuel oil used per waste ion exchange resin increases. Table 3 shows an example where either water or light oil and no emulsifier are added, where (R/W) is the weight ratio of the resin (F) and water, and (R/O) represents the weight ratio of the resin (F) and light oil.

[Table] According to this example, the emulsion stability is not sufficient, so
It goes without saying that the object of the present invention cannot be achieved by using this emulsion. Although light oil is used as the fuel oil in the above-described embodiments, the present invention is not limited thereto, and heavy oil, kerosene, waste oil, waste solvent, etc. may also be used. The emulsifier is preferably a nonionic surfactant; if a cationic or anionic surfactant is used, it will react with the waste ion exchange resin and reduce the emulsifying ability, making it difficult to maintain stable emulsivity for a long period of time. In the present invention, as described above, a wetted coarse waste ion exchange resin is mixed with fuel oil and water in the presence of an emulsifier to form a stable oil-in-water three-component emulsion; This is then sprayed and combusted. That is, as shown in the combustion system diagram in FIG.
It is sprayed into the furnace 4 and burned. At this time, it is preferable to carry out spray combustion under auxiliary combustion. In the illustrated apparatus, an auxiliary fuel oil supply conduit having a pump 5 and a nozzle 6 is provided. Note that 7 is a blower for supplying combustion air, 8 is a compressor for supplying pressurized air for atomization, 9 is an emulsifier, 10 is a fuel oil supply pipe, 11 is a water supply pipe, and 12 is a humidifier. conduit for supplying coarse waste ion exchange resin, 13
indicate emulsifier supply pipes, respectively. By incinerating the waste ion exchange resin in this way, various superior effects can be obtained compared to the case of water-in-oil emulsion. First, increasing the amount of water added lowers the viscosity of the emulsion (it increases in the case of water-in-oil type), so the amount of water added can be easily increased when lowering the exhaust gas temperature to a specified level. Therefore, it is possible to maintain the amount of combustion air to a minimum. Second, the amount of fuel used per amount of waste ion exchange resin can be reduced, and third, even when using high viscosity oil such as C heavy oil, the viscosity of the emulsion is reduced by the continuous phase. Since the viscosity of water converges to a certain level, fluidity that can be sprayed at room temperature can be obtained.Furthermore, even if the emulsion flows, there is no accumulation of static electricity, so there is a risk of ignition and explosion in the gas phase. (Water-in-oil type is highly dangerous)
This effect can be obtained. Next, FIG. 4 shows an example in which various oil-in-water emulsions were combusted using the apparatus shown in FIG. In addition, (F), (O/W), (R/L) in the same table
indicates the same thing as mentioned above.

[Table] As described above, according to the present invention, wet coarse waste ion exchange resin can be effectively incinerated. Regarding kerosene and diesel oil (O/W),
As long as (R/L) was kept the same, the emulsion stability and room temperature fluidity were almost the same. As detailed above, various excellent effects can be obtained according to the present invention.To explain in more detail here, one of them is that it facilitates complete combustion and reduces the amount of exhaust gas. It will be done. In other words, in order to reduce the amount of exhaust gas per amount of waste ion exchange resin processed, it is desirable to convert the resin into liquid fuel and bring the amount of combustion air close to the theoretical combustion air ratio.
In addition, in order to completely burn the resin, it is necessary to pass it through a high temperature zone as much as possible, but in the present invention, the resin must have good fluidity so that it can be mixed with fuel oil etc. and handled as a liquid fuel. A stable homogeneous dispersion is made and this is sprayed and burned.
Since the resin always passes through the high-temperature flame, its combustion can be carried out efficiently and complete combustion can be achieved. Secondly, it can save fuel and
The effect is that NOx can also be reduced. That is, if the uniform dispersion of the emulsion can be stably maintained, steady spray combustion can be maintained and ignition of the resin can be stabilized, so there is no need to excessively raise the temperature in the furnace necessary for complete combustion. In general incineration treatment, when the temperature inside the furnace becomes excessively high, the amount of combustion air is increased to lower the temperature, but in the present invention, the calorific value of the waste resin emulsion is reduced by adding water. Since it can be easily adjusted by changing the amount, it is possible to prevent excessive rise in the furnace temperature while maintaining the combustion air amount close to the theoretical air amount, mainly by changing the (O/W). Furthermore, since spray combustion is performed under auxiliary combustion when (O/W) is small and the calorific value of the emulsion is low, the temperature inside the furnace can be adjusted by controlling the auxiliary combustion fuel. The addition of water greatly contributes to NOx reduction in terms of both preventing the temperature inside the furnace from rising excessively and making the combustion flame temperature distribution uniform.
It is also desirable to use as little fuel as possible per waste ion exchange resin, but in the case of water-in-oil emulsions, as is clear from the comparative example in Table 2 (O/
If W) is lowered or (R/L) is increased, fluidity deteriorates and stable spray combustion is difficult to obtain. On the other hand, in the oil-in-water emulsion according to the present invention, complete combustion is easy even when the ratio (R/L) is (60/40), and therefore the amount of fuel used can be reduced. Thirdly, there is an effect that pre-treatments such as pulverization and drying can be omitted. General ion exchange resins are thermosetting polymeric substances whose basic constituents are crosslinked copolymers of styrene and divinylbenzene, and waste ion exchange resin particles contain a large amount of water. The drying speed of this is extremely slow. However, in the present invention, since the oil-in-water emulsion can be spray-combusted to produce a high-temperature combustion flame, even waste ion exchange resin with a particle size of about 1 mm can be crushed and finely divided in the flame. In other words, during combustion, the rate of heating inside the particles is faster than the rate of escape of water contained within the resin particles.
Particles are crushed by internal water vapor pressure. Thus, complete combustion can be achieved without pretreatment.
The emulsifier 9 in the apparatus shown in FIG. 1 can be of various types, such as a vibration type, a stirring type, a turbulent mixing type, a jet type, an impact type, and an ultrasonic type, and the furnace 4 can also be of a horizontal type or a vertical type. It can be installed in spray combustion furnaces and other cyclone combustion furnaces.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and is a schematic diagram of a waste ion exchange resin incineration treatment apparatus. 1: emulsion tank, 4: furnace, 10: fuel oil supply pipe, 11: water supply pipe, 12: waste ion exchange resin supply pipe, 13: emulsifier supply pipe.

Claims (1)

[Claims] 1. A wetted coarse waste ion exchange resin is mixed with fuel oil and water in the presence of an emulsifier to form a stable oil-in-water three-component emulsion, which is then mixed alone or with auxiliary combustion. A method for incinerating waste ion exchange resin, which is characterized by spraying and burning it at a bottom. 2 The composition range of the emulsion is such that the weight ratio of fuel oil and water is 70:30 to 20:80, and the weight ratio of waste ion exchange resin to the mixed liquid of fuel oil and water is 20:80 to 20:80.
Claim 1 characterized in that the ratio is 70:30.
The method for incinerating waste ion exchange resin described in .