JP2007113271A - Asbestos scattering prevention method by making use of soft epoxy resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of carrying out long term asbestos scattering prevention of an asbestos spraying layer of a building etc., or surely preventing the scattering of asbestos in the case of separation work and processing separated objects for stabilizing them. <P>SOLUTION: A soft epoxy resin is sprayed on a layer including asbestos to permeate asbestos with the soft epoxy resin. The building is used as it is or the separation work of the layer including asbestos is carried out. After asbestos has been permeated with the soft epoxy resin by injecting the soft epoxy resin into the layer including asbestos, the separation work of the layer including asbestos is carried out since the isolated resin is sucked. The layer including the separated asbestos is heated at 1,350°C or higher to stabilize it. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a method for preventing asbestos from being scattered when an asbestos sprayed building is maintained as it is or when a layer containing asbestos is peeled off.

Asbestos has industrially excellent characteristics such as heat resistance and wear resistance, and has been widely used as a spraying material as a heat insulating material, a heat absorbing material, a sound absorbing material, and the like in construction. Recently, however, the number of lung cancer and mesothelioma patients that are thought to be caused by asbestos has increased and has become a major social problem.
The asbestos sprays used so far are about 70% asbestos for sound absorption and condensation prevention, about 60% asbestos for fireproof coating, and 30% asbestos for other asbestos-containing sprays. Or 5% or less. Currently, those with an asbestos content of 1% or more are prohibited. However, it is desired to completely prevent the asbestos from being scattered or to remove the asbestos-containing material from those already installed. In the latter case, the problem is that asbestos is scattered. The manual of the former Ministry of Construction stipulates that the building is covered with a sheet, sprayed with water mixed with chemicals to prevent splashing, and workers wear dedicated protective clothing and dust masks. In addition, the Ordinance of the Ministry of Health and Welfare stipulates that the disposal method should be double-packed with water-resistant sheets and buried in a management-type disposal site that prevents outflow into soil or water. However, in practice, asbestos scattering may be observed near the dismantling and removal work site, and there is a need for a method that can more reliably prevent asbestos scattering.

Patent Document 1 discloses a method of preventing the diffusion to the outside by covering the outside of the region of the asbestos layer to be removed with a box-type hood and sucking the peeled asbestos. In Patent Document 2, as a method to save labor by omitting the whole surface curing with plastic sheet and the whole surface application of curing agent or anti-scattering agent, a working space surrounded by transparent panels is formed to remove asbestos. A method is shown in which the surface is locally cured and then sucked into a vacuum vehicle via a flexible hose. Furthermore, Patent Document 3 discloses a method of sealing by blowing bubbles from the nozzle around the inside of the hood in order to reliably prevent the asbestos from scattering to the outside of the hood even when the asbestos removal tool is moved. . Further, in Patent Document 4, as a method for reducing or eliminating the oxidation activity on the surface of asbestos, the alkali metal component and the alkaline earth metal component are immersed in or brought into contact with a solvent that dissolves the alkali metal component and the alkaline earth metal component. A method for cultivating filamentous fungi after washing and reducing the amount is shown.
JP-A-8-28027 JP-A-9-72111 JP-A-9-125707 JP, 2005-152780, A All of the methods of Patent Documents 1 to 3 focus on forming a closed system so that asbestos is not dissipated to the outside, but it is not easy to do it completely in field work. . Moreover, it is not easy to perform the method of patent document 4 to the whole wide asbestos spraying layer.

On the other hand, with regard to the use of epoxy resin for building-related purposes, hard materials have been used for repairing cracks in concrete. In that case, it is a necessary condition to have a strength comparable to concrete, and the soft epoxy resin used in the present invention was out of scope.

  The present invention reliably prevents the asbestos from scattering while the asbestos-containing layer is left as it is, or reliably prevents the asbestos from being scattered during the asbestos spray layer peeling operation, and completely stabilizes the peeled layer. It is intended to provide a way to do that.

The eye of the present invention for solving the above-mentioned problems is that a soft epoxy resin is used to efficiently infiltrate asbestos, and because the degree of curing is small, unlike ordinary curing agents, there is an unreasonable force when peeling off. It is not difficult to scatter the asbestos, and it is less likely to cause problems such as waste gas and dust during the post-treatment heating.
The first of the concrete means is to supply the asbestos-containing layer with soft epoxy resin of 20% or more of its volume by injection, etc. to make the asbestos infiltrated with the soft epoxy resin, and use the building as it is It is to be.

The second specific means is that a layer containing asbestos is supplied to the layer containing asbestos to be removed by injecting a soft epoxy resin of 20 volume% or more of the volume by infusion, etc., and asbestos is infiltrated with the soft epoxy resin. It is to perform the stripping work.

  The third specific means is to inject a soft epoxy resin of 20% by volume or more into the layer containing asbestos to be removed, infiltrate the asbestos with the soft epoxy resin, and then suck the free soft epoxy resin. After that, the work of stripping the layer containing asbestos is performed.

A fourth specific means is to infiltrate the layer containing asbestos to be removed with a soft epoxy resin, and then heat the layer containing asbestos peeled off to 1350 ° C. or more to stabilize it.

According to the method of claim 1, asbestos is infiltrated and the spray layer is integrated with a certain degree of flexibility, and asbestos scattering can be efficiently prevented in that state.

According to the method of claim 2, asbestos is infiltrated and the spray layer is integrated with a certain degree of flexibility, and the subsequent removal operation proceeds in the form of peeling to suppress generation of asbestos fragments. As a result, scattering of asbestos can be efficiently prevented.

According to the method of claim 3, a necessary and sufficient amount of the soft epoxy resin is supplied to the layer containing asbestos to be removed, and the maximum effect can be obtained at a minimum cost.

  According to the method of claim 4, it is possible to completely detoxify the asbestos contained in the peeled asbestos-containing layer and to burn the soft epoxy resin.

Even when using a building with asbestos-containing layers as it is, asbestos may be scattered, especially as a result of natural disasters and other cases where the asbestos layer is overpowered and destroyed. It can be considered to be almost the same as when the layer containing asbestos is peeled off. In either case, a soft epoxy resin is first sprayed on the surface of the asbestos-containing layer. The kind of soft epoxy resin to be used is selected in consideration of both the asbestos scattering prevention effect at the time of peeling and the detoxification of the generated gas at the time of final heating. Among these, the asbestos scattering prevention effect at the time of peeling is the effect of wetting the asbestos fibers to suppress the scattering and the softness unique to the soft epoxy resin, which peels without excessively destroying the asbestos spray layer. It depends on the combination of the effects of suppressing fiber scattering. In view of these effects, an Everbond system is suitable.
Other resins that have similar effects in terms of adhesion include polyvinyl acetate, but it is used for this purpose because it takes a long time to harden, its strength is too weak, and its change with time is large. Therefore, the quality is inferior.

When the supply of the soft epoxy resin is performed by injection, the amount of the soft epoxy resin to be used is preferably 20% by volume or more, preferably 50% by volume or more of the volume of the asbestos spray layer to be removed as shown in FIG. As a result, the soft epoxy resin can infiltrate the asbestos spray layer and wrap the asbestos fibers. Following this, the asbestos spray layer is peeled off by machine or manpower. At this time, the asbestos piece peeled off from the main body of the asbestos spray layer is also wrapped with a soft epoxy resin, or at least a soft epoxy resin adhering does not float in the air, so it can be recovered by cleaning the work floor .

  In order to further suppress the asbestos scattering during peeling and at the same time reduce the amount of soft epoxy resin used, instead of the work of 0015, first, as shown in Fig. 2, the soft epoxy resin is injected into the layer containing asbestos. And then suck. The amount of the soft epoxy resin in this case is 20% by volume or more of the volume of the layer containing asbestos to be removed. Further, after the press-fitting, suction is performed to feed back the soft epoxy resin that is excessively supplied and is in a free state so that it can be effectively used for injection at another location. Furthermore, the reduction in the amount of the soft epoxy resin remaining in the layer containing the separated asbestos has an effect of reducing post-treatment. Decreasing the amount of the soft epoxy resin remaining in the structure also has an effect of leaving no adverse effects later. In this way, a necessary and sufficient amount of soft epoxy resin for infiltrating the asbestos fibers can be supplied by press-fitting and subsequent suction. Subsequent stripping of the asbestos layer is the same as described in 0015.

After the asbestos-containing layer is peeled off, the asbestos-containing layer remaining on the structure surface is sprayed with a soft epoxy resin and then finished with a wire brush or the like.
In that case, the required amount of soft epoxy resin is about 3 g or more per 1 m ² . Furthermore, after the work, depending on the situation, the entire surface after removal is sprayed with resin as necessary. The amount is about 3 g or more per 1 m ² . As a result, the asbestos remaining on the spray surface can be completely fixed.

  The peeled layer containing asbestos is sealed in a bag and transported to a heat treatment plant. Therefore, the furnace is charged and heated in a furnace maintained at 1350 ° C. or higher. This heating makes asbestos harmless. Also, the soft epoxy resin is completely pyrolyzed and burned. In addition, the waste gas from this heating furnace is dust-collected to prevent one part of asbestos from coming out of the system as dust. In addition, when the collected dust contains fine asbestos, it is desirable to make the dust into pellets or briquettes, and charge it again into the heating furnace for stabilization.

A soft epoxy resin (EverBond) was injected into the layer of 8 mm thickness containing 70% asbestos, sprayed on the ceiling of the gymnasium, 40% by volume of the layer containing asbestos. Thereafter, the air collected from the vicinity was measured every six months for five years, but no asbestos fibers were detected.

The spraying layer having a thickness of 8 mm containing 70% asbestos sprayed on the ceiling of the gymnasium was peeled off as follows. A soft epoxy resin [EverBond] was injected by 50% of the volume of the layer containing asbestos, and then the peeling operation was performed manually 30 minutes later. At this time, the measurement result of the atmosphere at the operator's position (the number of asbestos fibers of 5 microns or more per 1 l of air) was 2.2 / l or less.
After peeling, ² g of the same silicone resin was sprayed per 1 m ² to remove the remaining asbestos layer with a wire brush. The measurement result of the atmosphere at the position of the operator at this time was 1.4 lines / l or less. Thereafter, ² g of the same soft epoxy resin was sprayed per 1 m ² to complete the operation.

The 8 mm thick spray layer containing 70% asbestos sprayed on the ceiling of the gymnasium was peeled as follows. 50 vol% of the volume of the layer containing asbestos was injected into the layer containing asbestos at an atmospheric pressure of 1.1 atm. The soft epoxy resin [EverBond] was sucked after 5 minutes. The amount of soft epoxy resin sucked was 15% of the amount injected. The sucked soft epoxy resin was used by mixing with the soft epoxy resin for press-fitting at the following place. 30 minutes after the suction, the asbestos layer was peeled off manually. The atmosphere measurement result at the operator's position was 0.4 or less asbestos fibers / l. After peeling, ² g of the same soft epoxy resin was sprayed per 1 m ² , and the remaining asbestos layer was removed with a wire brush. The measurement result of the atmosphere at the operator's position at that time was 0.2 pieces / l or less. Thereafter, ² g of the same soft epoxy resin was sprayed per 1 m ² to complete the operation.

The asbestos exfoliated in Example 3 was charged into a heavy oil combustion heating furnace maintained at 1500 ± 30 ° C. and dissolved. The generated slag was crushed and used as building material instead of stone.
Since the dust collection dust of the waste gas treatment system contained 5 fibers / g of asbestos fibers, the pellets were 5 to 7 mm in diameter and charged again into the heating furnace.

The method of the present invention can also be used when dismantling buildings and the like containing asbestos.

The effect of the amount of soft epoxy resin sprayed on the amount of asbestos scattered during the stripping operation is shown. 1 illustrates the most preferred implementation system of the present invention for reducing asbestos scattering.

Claims (4)

A method for preventing asbestos scattering, comprising supplying a soft epoxy resin having a volume of 20% by volume or more to a layer containing asbestos by injection or the like, and infiltrating the asbestos with the soft epoxy resin. Asbestos scattering is characterized by supplying a soft epoxy resin of 20% by volume or more to the layer containing asbestos by injection or the like and infiltrating the asbestos with the soft epoxy resin, and then stripping off the layer containing the asbestos. Prevention method. Injecting 20% or more by volume of soft epoxy resin into the layer containing asbestos, infiltrating the asbestos with the soft epoxy resin, and then sucking the free soft epoxy resin, then stripping the layer containing the asbestos Asbestos scattering prevention method characterized by performing. A method for preventing asbestos scattering, comprising heating and stabilizing the layer containing asbestos peeled off according to claims 2 and 3 to 1350 ° C or higher.

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