JP2011098303A - Treatment method for preventing scattering of asbestos - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make asbestos a non-scattered state beforehand when performing detoxification treatment of asbestos, and to maintain asbestos in a safe state during detoxification operation or until the detoxification treatment. <P>SOLUTION: Treatment method for preventing scattering of asbestos comprises a first process for feeding asbestos, an asbestos-containing subsidiary material, and thermoplastic resin components, a second process for crushing and mixing the fed materials, a third process preferably including a process mixing an asbestos melting agent, and melting thermoplastic resins and mixing the whole fed materials, a fourth process for (extrusion) molding the mixture, and a fifth process for solidifying the thermoplastic resins. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for treating asbestos sprayed mainly on a base material such as a ceiling, a wall, or a pillar as a heat insulating material, and relates to a method for containing asbestos to prevent the asbestos from being scattered.

  In recent years, aging, deterioration, and scattering of asbestos used for heat insulating materials have become a major problem, which is a serious problem as so-called asbestos pollution. That is, lightweight and fine asbestos is a substance that is easily scattered in the atmosphere, has a sharp shape like a fish bone, and is difficult to discharge by human self-cleaning action when pierced into a mucous membrane or the like.

  For this reason, it is said to cause various health problems and diseases. Asbestos inhalation causes pleural apex (pleural thickening), asbestosis (asbestosis), emphysema, and malignant mesothelioma and lung cancer. Has been pointed out to cause. Moreover, since it is said that these disorders develop after illness or inhalation after 10 to 20 years, measures need to be taken as soon as possible.

Therefore, asbestos sprayed on the ceiling, etc. is peeled off after dismantling workers wear complete protective clothing and take measures such as surrounding the work site with a resin sheet so that it will not be scattered around. After that, measures were taken for disposal. However, safety management for workers must be made very strict, and since it is easy to scatter to the atmosphere, measures to prevent it from scattering to the surroundings are extremely large. In addition, the asbestos that has been peeled off cannot be disposed of as it is, and it is difficult to corrode. I had to. Of course, it is needless to say that various sub-materials used for the processing work need to be completely processed.

At present, asbestos and asbestos-containing materials are landfilled in the final disposal site as specially controlled industrial waste, but there are limits to this. For this reason, various asbestos detoxification techniques have been proposed. A typical example is a closed electric furnace melting method proposed in Patent Document 1.

 Moreover, there exists patent document 2 as an asbestos detoxification processing method. According to this, asbestos can be rendered harmless by mixing asbestos and a CFC decomposition product and heat-treating the mixture.

However, as described above, it is inevitable that a large amount of dust is generated when the asbestos layer is peeled off, and dust is also generated during the transfer of asbestos for processing. It cannot be denied that there is an influence, and there is a big problem in practical use.

Japanese Patent No. 3085959 JP 2005-168632 A JP 2007-308771 A

  The purpose of the present invention is to preliminarily place asbestos in a non-scattering state in the process of detoxifying asbestos, and asbestos is safe during the detoxification operation or before detoxification treatment. The purpose is to keep it in a state. Needless to say, the present invention provides a method for treating the auxiliary materials used in various operations at the same time and completely preventing the asbestos from being scattered until the complete detoxification treatment.

The gist of the present invention is a method for preventing asbestos from scattering, a first step of adding asbestos, an asbestos-containing auxiliary material, a thermoplastic resin component, a second step of crushing and mixing the above-mentioned input, a thermoplastic resin component And a fourth step of (extrusion) molding the mixture, and a fifth step of solidifying the thermoplastic resin component. Preferably, it is desirable to incorporate an asbestos melting agent in the first step, the second step or after the second step.

  The present invention provides a method for treating asbestos sprayed on the surface of a base material such as a building as described above, and has a sufficiently stable shape until the permanent detoxification treatment as described above is performed. It is possible to maintain and maintain a non-scattering state. In addition, when performing the detoxification process, it can be safely transported and its workability is also ensured.

In other words, asbestos with scattering properties is solidified and molded into a desired shape, making it easy to store such asbestos, preventing scattering of asbestos during transportation, and improving transportation efficiency and reducing costs by reducing volume during transportation. Thus, the supply to the heat detoxification device during the asbestos detoxification treatment and the stabilization of the detoxification treatment can be achieved.

  The asbestos treatment method of the present invention consists of first to fifth steps, and is a technique for enclosing asbestos with a thermoplastic resin. Furthermore, it is a technique in which asbestos sprayed on the surface of a base material such as a building or a steel frame is preferably sealed with a thermoplastic resin together with an asbestos melting agent. The asbestos that can be treated is not particularly limited, and is a technique for detoxifying all asbestos such as chrysotile, crocidolite, amosite, anthophyllite, tremolite, and actinolite.

"First step"
Asbestos, asbestos-containing auxiliary material, thermoplastic resin component is a process of removing asbestos formed on the surface of base materials such as buildings and packing it, asbestos-containing auxiliary material, curing sheet and worker protection It is a process including collecting clothes and bagging, and if necessary, adding a thermoplastic resin component such as polyethylene or polypropylene. Specifically, it is a step of putting the peeled asbestos and the asbestos-containing auxiliary material together with the bag together with the thermoplastic resin into a hopper and pulverizing with, for example, a screw. The thermoplastic resin content is about 30 to 70% by weight with respect to 100 parts by weight of asbestos, and various auxiliary materials are generally made of a thermoplastic resin. In some cases, it may not be necessary to add a new thermoplastic resin component. Further, the thermoplastic resin component may be, for example, a waste material used for a beverage or food container.

"Second step"
It is a step of crushing and mixing the various inputs. That is, it is a step of adding the asbestos component, the auxiliary material, and if necessary, the thermoplastic resin component and mixing the whole.

"Third step"
In this process, the thermoplastic resin is melted to form the “sea part” and other inputs (asbestos) are mixed as the “island part”. That is, it is a step of heating and melting the thermoplastic resin content in the mixture to 120 to 150 ° C. to make “sea part”.

"4th process"
This is a step of molding the above mixture with the thermoplastic resin content as “sea part” into an arbitrary shape. Usually, extrusion molding, molding, or the like can be employed.

"5th process"
In this step, the molded product obtained in the previous step is cooled as it is to solidify the thermoplastic resin component. That is, the thermoplastic resin component is heated and melted, and the asbestos component is surrounded by the molten thermoplastic resin component to form a desired shape, and then the thermoplastic resin component is solidified to prevent asbestos from scattering. It is a process.

"Add process"
It is desirable to mix the asbestos melting agent in the first step, the second step, or after the second step. Such an asbestos melting agent is an alkaline compound and is usually a calcium compound or a silicon compound. For example, calcium fluoride, calcium carbonate, calcium oxide, calcium hydroxide, or silicon dioxide is used.

As described above, the basic flow of the present invention is a method that should be a pretreatment for the detoxification treatment of asbestos. A bag containing asbestos, a bag containing auxiliary materials, and if necessary, a thermoplastic resin component is added thereto. Then, this is crushed (pulverized) and mixed, and then a chemical is added thereto. The thermoplastic resin component is then melted and mixed together, and then extruded into a desired shape, for example, and then the thermoplastic resin component is mixed. It is a technology to solidify.

  For this reason, the obtained molding is a molding in which the asbestos content is “island” and the thermoplastic resin content is “sea”, and the non-scattering property, volume reduction, and stable shape of asbestos are maintained. It will be. In other words, the asbestos component, which is said to be highly scatterable, is embedded in the thermoplastic resin and can be stored in a stable state until final disposal.

When further referring to the present invention, the place of the above detoxification treatment is not particularly limited, and in some cases, the process is performed at the work site where asbestos is peeled and crushed to ensure safety, and thereafter This makes it easy to transport, and it is also possible to move it to another place and move it to the final disposal process.

Referring to secondary materials here, for example, a curing sheet that completely covers the work site where asbestos is peeled off, or a bag containing asbestos, these are used in very large quantities and are not completely discarded. Must not. The same applies to work clothes worn by workers. In addition, these auxiliary materials are usually made of thermoplastic resins such as polyethylene and polypropylene. The present invention makes high use of this fact, and intends to treat all resin components discharged during the treatment of asbestos together with asbestos.

Example 1
Hereinafter, an example of the present invention will be further described according to the order of steps. Polyethylene (including secondary materials) (100 parts by weight) is added to the asbestos pulverized product (100 parts by weight). Added and mixed. The polyethylene to be added is preferably pelletized in advance. They were then heated to melt the polyethylene and encapsulate asbestos, which was extruded. This was further cooled to solidify the molten polyethylene. As a result, the polyethylene part formed the “sea part” and the asbestos part formed the “island part”. It was found that no asbestos was scattered from the solidified product.

(Example of final disposal)
The present inventors have already provided an efficient asbestos final disposal method in Patent Document 3, and the molded product of the present invention can be directly applied to this final disposal method. That is, the molded product obtained in the present invention is introduced into a thermoplastic resin decomposition furnace and heated to oily or vaporize the thermoplastic resin. Specifically, the asbestos solidified product is heated at about 300 to 700 ° C. in an electric furnace to oily or vaporize the thermoplastic resin component. When no asbestos melting agent is present, heating at about 1000 ° C. is necessary. That is, the asbestos is burned and the asbestos is heated and melted using the amount of heat obtained. As a result, the thermoplastic resin component used in the treatment of asbestos can be completely recycled as fuel. Of course, the asbestos fiber form disappears, the crystal structure collapses, and the like can be rendered harmless.

(Evaluation 1)
When observed with a microscope, the former example showed a decrease in fiber, and the treatment at 700 ° C. showed no fiber at all. In the latter example, the fiber remained undegraded. From this, it was found that asbestos was rendered harmless by the amount of heat of the thermoplastic resin, and the effect of the asbestos melting agent was also high.

(Evaluation 2)
The observation with a scanning electron microscope does not confirm the presence of fiber in the former. This indicates that the influence on the living body is low.

The present invention provides a method for treating asbestos, which can maintain a sufficiently stable shape and maintain a non-scattering state until the permanent detoxification treatment as described above is performed. It is a thing. Therefore, the safety during the final disposal of asbestos and the safety during transportation to the final disposal site are ensured, and its applicability is extremely high.

In addition, the characteristics of the point of maintaining a stable shape (stabilization) can be further stated. In final disposal, asbestos can be quantitatively supplied and processed quantitatively, and there is no temperature fluctuation in the disposal device and it is constant. This is to enable stable and reliable detoxification treatment. In other words, the following points, which are a concern when a resin containing asbestos is added without solidification without being solidified and molded, are improved. In other words, asbestos is solidified and molded into a predetermined shape with resin to prevent clogging due to resin welding at the supply port in the heat detoxification device (final disposal device), and formation of carbides and clinker on the inner wall surface of the device This makes it possible to avoid operational troubles such as a decrease in the detoxification heat treatment capacity due to heat transfer failure due to heat transfer, and is a highly practical technology.

Claims (10)

  Asbestos scattering prevention treatment method, asbestos, asbestos-containing auxiliary material, first step of adding thermoplastic resin component, second step of crushing and mixing the above-mentioned input material, all the thermoplastic resin content is melted A method for preventing asbestos from scattering, comprising: a third step in which the mixture is mixed; a fourth step in which the mixture is molded; and a fifth step in which the thermoplastic resin component is solidified. The method for preventing scattering of asbestos according to claim 1, wherein the fourth step is extrusion molding.   The method for preventing scattering of asbestos according to claim 1 or 2, wherein the thermoplastic resin component is polyethylene or polypropylene.   The method for preventing asbestos from scattering according to claim 3, wherein the thermoplastic resin component is various auxiliary materials made of polyethylene or polypropylene.   The method for preventing scattering of asbestos according to any one of claims 1 to 4, wherein the thermoplastic resin component is heated to 120 to 150 ° C.   The asbestos scattering prevention treatment method according to claim 1, wherein an asbestos melting agent is mixed after the first step, the second step, or the second step.   The method for preventing scattering of asbestos according to claim 6, wherein the asbestos melting agent is a calcium compound.   The method for preventing asbestos from scattering according to claim 7, wherein the calcium compound is selected from calcium fluoride, calcium carbonate, calcium oxide, and calcium hydroxide.   The method for preventing scattering of asbestos according to claim 6, wherein the asbestos melting agent is a silicon compound.   The method for preventing scattering of asbestos according to claim 9, wherein the silicon compound is silicon dioxide.