WO2008072467A1

WO2008072467A1 - Method for melting asbestos and apparatus for melting asbestos

Info

Publication number: WO2008072467A1
Application number: PCT/JP2007/072842
Authority: WO
Inventors: Shinichi Ikeda; Norio Umeyama
Original assignee: National Institute Of Advanced Industrial Science And Technology
Priority date: 2006-12-15
Filing date: 2007-11-27
Publication date: 2008-06-19
Also published as: JPWO2008072467A1

Abstract

This invention provides a method for rendering asbestos unharmful, which can significantly reduce the cost necessary for asbestos treatment and is satisfactorily safe in the removal of asbestos. Light from an infrared light emitting source is collected at asbestos or an asbestos-containing material to locally heat asbestos, the asbestos-containing material, or asbestos contained in the asbestos-containing material to a predetermined temperature, and thus to melt asbestos, whereby the asbestos is rendered unharmful. In the method, an apparatus for melting asbestos is used. The apparatus comprises a light emitting source and means for collecting light emitted from the light emitting source at asbestos or the asbestos-containing material.

Description

Specification

Method for melting asbestos and apparatus therefor

Technical field

The present invention relates to a method for melting asbestos and an apparatus therefor, and more particularly to a method for detoxifying asbestos by melting asbestos and extinguishing its fibrous form, and an apparatus therefor. is there.

Background art

[0002] Asbestos (natural asbestos) is a naturally occurring fibrous mineral that includes chrysotile (white asbestos), crocidolite (blue asbestos), and amosite (tea asbestos). It has excellent potency, heat resistance, insulation, mechanical strength, and is easy to process, so it has long been widely used as an industrial material for electrical products, automobiles, and building materials such as building roofing materials and wall materials. I came.

[0003] Thus, asbestos has excellent characteristics, but has fine needle-like 'fibrous crystals', and when inhaled by humans, a part of it remains in the respiratory organs for a long time, and asbestos lungs. It causes serious health problems such as lung cancer, malignant mesothelioma, and so on!

With regard to this asbestos problem, since July 2005, various measures have been put in place by the government in earnest. Specifically, the use of building materials that may scatter asbestos is regulated. At the same time, legislation has been put in place, such as obligating the removal of asbestos as a general rule at the time of expansion and reconstruction or dismantling.

[0004] As a disposal method of waste containing such asbestos (waste asbestos material), it has been conventionally packed in a double plastic bag so that it does not scatter or is made concrete, and it is underground in the final treatment plant. The landfill method was taken.

However, due to environmental problems, landfill sites are lacking.In recent years, instead of such landfills, an asbestos melting point of about 1500 ° C or higher is heated in an electric furnace, etc. Detoxification of asbestos, such as in construction waste, has been carried out.

[0005] For example, Patent Document 1 discloses a method for separating asbestos from a waste material of a fiber-reinforced cement board containing asbestos and detoxifying the separated asbestos, and the obtained solid and residue. Describes a method for producing a fiber-reinforced cement board that is reused as a part of the raw material. In this method, the fiber reinforced cement board waste containing asbestos is roughly crushed or crushed, then wet pulverized, and 60% asbestos is recovered from the resulting slurry by wet separation. The asbestos content is separated into 0 to 10% by weight or less, and the solid content is baked at 700 to 1000 ° C to decompose the asbestos in the solid content. It is a harmless component mainly composed of Mg 2 SiO 3.

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[0006] Also, in Patent Document 2, paying attention to the fact that the fluorocarbon decomposition product produced by the fluorocarbon detoxification treatment contains calcium fluoride, by using this fluorocarbon decomposition waste as a melting agent, low energy is used. A method for detoxifying asbestos is proposed. In other words, it was produced by substances containing asbestos (slate plates containing asbestos, roof tiles, water pipes, automobile brakes, acetylene cylinder fillers, fireproof coatings, etc.) and detoxification treatment of CFCs. By mixing or kneading the CFC decomposition product, and then heat-treating the mixture at a low temperature of 600 ° C or lower, asbestos is reliably decomposed, causing the fiber form of asbestos to disappear, the crystal structure to collapse, etc. To make it pollution-free.

[0007] Further, in Patent Document 3, a method for melting asbestos waste mixed with aluminum powder by arc discharge or heating by thermal plasma, Patent Document 4 describes asbestos pretreated with a melting agent composed of a boron compound. A method of melting slate waste materials containing about 1000 ° C is proposed, and Patent Document 5 proposes a method of melting asbestos-containing waste from 1200 to 1700 ° C without additives. Yes.

[0008] However, since any asbestos detoxification treatment method uses a method in which the asbestos used in a building or the like is removed and then collected in a treatment plant and melted, it was sprayed on a wall material. When removing asbestos, etc., it is necessary to prepare powerful equipment and safety measures so that dust containing asbestos does not leak out of the workplace, and in this situation, asbestos processing costs are very high. In addition, it is not safe enough to remove asbestos.

Patent Document 1: JP 2000-271561 A

Patent Document 2: JP 2005-168632 Koyuki

Patent Document 3: Japanese Patent Laid-Open No. 08-084969 Patent Document 4: JP-A-2005-279589

Patent Document 5: Japanese Patent Laid-Open No. 09-019672

Patent Document 6: Japanese Patent Publication No. 5-34317

Patent Document 7: International Publication No. 2005/1725 Pamphlet

Disclosure of the invention

Problems to be solved by the invention

[0009] The present invention has been made in view of the circumstances as described above, and greatly reduces the cost of processing asbestos, and also has sufficient safety when removing asbestos. The purpose is to provide a method of detoxifying the best.

Means for solving the problem

[0010] The above-mentioned problem in conventional asbestos detoxification treatment is mainly in the asbestos removal process from wall materials and the like, and in order to solve the problem, a method that can simultaneously perform the asbestos removal process and the detoxification process. is required. On the other hand, as described above, asbestos detoxification method is very effective in terms of cost, environmental safety, etc. However, if a conventional practical heating and melting method, such as a heating method using a gas burner flame, is applied to the asbestos sprayed on the wall material, the temperature of the substrate such as the wall material and its surroundings also rises. Therefore, it is almost impossible to melt only asbestos or only the spray material containing asbestos by uniformly heating to a predetermined temperature.

[0011] As a result of studies on a method for melting asbestos sprayed on a wall material, the present inventors have concentrated light from a light source such as a halogen lamp on asbestos or an asbestos-containing member. We obtained the knowledge that asbestos can be rendered harmless by melting asbestos with heat and collapsing its fibrous form.

The present invention has been completed based on these findings, and provides the following asbestos melting method and apparatus.

(1) A method for melting asbestos, comprising melting asbestos, an asbestos-containing member, or an asbestos in an asbestos-containing member by condensing light from the light source on the asbestos or the asbestos-containing member. (2) The method for melting asbestos according to (1), wherein the light emitting source is a light source that emits light including infrared rays.

(3) The asbestos melting method according to (1), wherein the asbestos or asbestos-containing member is coated or sprayed on a plane, curved surface or polyhedral surface.

(4) Asbestos, an asbestos-containing member, or an apparatus for melting asbestos in an asbestos-containing member, comprising: a light emitting source; and means for condensing light emitted from the light emitting source onto the asbestos or the asbestos-containing member. A melting apparatus for asbestos, comprising:

(5) The asbestos melting apparatus according to (4), wherein the light source is an infrared irradiation lamp.

(6) The asbestos melting device according to (4), wherein the condensing means is a spheroid mirror, and is a reflecting mirror capable of condensing light from a light source in a dot shape. .

(7) The asbestos melting apparatus according to (4), wherein the condensing means is a reflecting mirror capable of condensing light from a light source in a linear shape.

(8) A device for melting asbestos, asbestos-containing members or asbestos in asbestos-containing members applied or sprayed on a plane, curved surface, or polyhedron surface (4) to (7) No! / Asbestos melting equipment as described in any of the above.

The invention's effect

[0013] According to the method and apparatus of the present invention, asbestos can be melted while attached to a wall that does not need to be peeled off from the wall or the like, the current cost can be greatly reduced, and the safety can be remarkably improved. Can be improved.

Brief Description of Drawings

FIG. 1 is a diagram showing an outline of a detoxification apparatus according to the present invention.

[Figure 2] Photograph of chrysotile before infrared condensing heat treatment

[Figure 3] Photo of chrysotile after infrared heat treatment

[Fig.4] Photograph of amosite before infrared heat treatment

[Fig.5] Photo of amosite after infrared heat treatment

[Figure 6] Photograph of crocidolite before infrared condensing heat treatment [Figure 7] Photograph of crocidolite after infrared heat treatment

[Figure 8] Photo of phase contrast microscope observation of chrysotile before infrared condensing heat treatment

[Figure 9] Photo of phase contrast microscope observation of chrysotile after infrared condensing heat treatment

[Fig.10] Photo of phase contrast microscope observation of amosite before infrared heat treatment

[Figure 11] Photo of phase contrast microscope observation of amosite after infrared condensing heat treatment

[Figure 12] Photo of phase contrast microscope observation of crocidolite before infrared heat treatment

[Fig.13] Photo of phase contrast infrared microscopic observation of crocidolite after infrared heat treatment

[Fig.14] X-ray diffraction pattern of chrysotile powder before infrared heat treatment

[Figure 15] X-ray diffraction pattern of chrysotile powder after infrared heat treatment

[Figure 16] X-ray diffraction pattern of mosite powder before infrared heat treatment

[Fig.17] X-ray diffraction pattern of amosite powder after infrared heat treatment

[Fig.18] X-ray diffraction pattern of crocidolite powder before infrared heat treatment

[Fig.19] X-ray diffraction pattern of crocidolite powder after infrared focused heat treatment

FIG. 20 is a diagram schematically showing a melting experiment method using a reflecting mirror.

[Fig.21] Cross-sectional photograph after rock wool on concrete melts

Explanation of symbols

[0015] 1: Elliptical reflector

2: Light source (halogen lamp)

3: Sample (asbestos or asbestos-containing spray material)

4: Concrete plate or iron plate

5: Melted part

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] In the present invention, asbestos, an asbestos-containing member, or an asbestos-containing member is collected by condensing light from a light-emitting source that emits light including infrared rays onto asbestos or a member containing asbestos. The asbestos in the member is locally heated to a predetermined temperature, whereby the asbestos is heated and melted to be detoxified.

Representative examples of asbestos in the present invention include chrysotile (white asbestos), clothidite (blue asbestos), and amosite (tea asbestos). It can be rendered harmless by a device.

[0017] Although it has been conventionally known that these asbestos melt at a high temperature of about 1500 ° C or higher by high-temperature heating of an electric furnace or the like, from a light source that emits light including infrared rays such as a halogen lamp. Until now, it has not been heated and melted by the absorption of light. That is, asbestos itself is a white, blue or brownish white fibrous mineral, it has not been known that it can absorb light and efficiently heat and melt it. A white substance is a force generally considered to be difficult to absorb light. Unexpectedly, it was found that when irradiated with light, it absorbs the light and is easily melted by heating. And asbestos has a very low thermal conductivity, it seems that it is likely to be heated and melted locally when the material containing asbestos is irradiated by collecting the radiated light from the heating source.

[0018] In the present invention, the light source that emits light containing infrared rays is typically a force S that uses an infrared irradiation lamp such as a halogen lamp or a xenon lamp, or a light source that emits light containing infrared rays. It is not limited to this. In addition, a reflecting mirror or a lens is used as a means for condensing the light from the light source on the best.

The apparatus used for melting asbestos in the present invention is not particularly limited as long as it has the light emitting source and means for condensing the light from the light emitting source. It is possible to refer to known heating devices described in Patent Documents 6 and 7, which are known as crystal growth devices. In particular, the crystal growth heating device described in Patent Document 7 is extremely small, can be used with a household 100V power source, and can be used at low cost, although the temperature can be raised to 2000 ° C. It has some advantages. The following melting experiment 1 was performed using this apparatus.

[0019] (Melting experiment 1)

An asbestos melting experiment was conducted using a small infrared central heating furnace.

Fig. 1 is a conceptual diagram showing an outline of a small infrared central heating furnace used for melting experiments. In the figure, 1 is an elliptical reflector, 2 is a light source such as a halogen lamp, and 3 is a sample.

As shown in the figure, the small infrared central heating furnace has two elliptical reflectors. One light source 3 such as a halogen lamp is installed at each focal point. The two reflecting mirrors are provided so that the other focal points coincide with each other, and the sample 3 is arranged at the focal point.

When the current is supplied to the lamp 3, the filament becomes red hot and emits infrared rays. By collecting the infrared rays at the sample position, the temperature of the sample is raised.

[0020] Three types of samples, chrysotile (Russia's Ural P4 class), amosite (South Africa) and crocidolite (South Africa), are used, each approximately 5mm square, and inserted into the tip of an alumina tube with an outer diameter of 6mm. Fixed.

Next, the alumina tube on which the sample was fixed was attached to the small infrared central heating furnace.

[0021] The small infrared fountain intensive heating furnace is equipped with two general-purpose halogen lamps of 650W, each capable of applying a voltage up to 100V. For example, in order to dissolve ruby with a melting point of 2050 ° C, it is necessary to apply a voltage of about 93V with the device.

In this melting experiment, all three types of asbestos could be melted by applying a voltage of 40 V to 50 V while flowing air at a rate of several hundred cc / min into the sample space. This force, et al., In the case of asbestos, that the force ^s I force can be melted at about about one-third of the power in the case of ruby, Ru.

[0022] FIGS. 2 and 3, FIGS. 4 and 5, and FIGS. 6 and 7 are photographs of the chrysotile, amosite, and clothite, respectively, observed directly with cameras before and after heating with the apparatus.

As is clear from these photographs, it was observed that the shape of the fibrous sample became smooth and the volume decreased. In addition, asbestos after melting is not wetted to the alumina tube used to hold the sample and is in the shape of a ball, so that asbestos absorbs more infrared rays than alumina and the temperature rises! S component force.

[0023] In addition, in order to confirm that the fibrous form does not remain in the melted chrysotile, amosite, and crocidolite samples, before and after the infrared focused heat treatment, respectively. The sample was subjected to phase contrast microscope observation and powder X-ray diffraction in accordance with JIS A 1481: 2006 “Method for measuring aspect content in building materials”. For phase contrast microscopy, the refractive index and dispersion color adopted are chrysotile (1.550, white), crocidolite (1 · 700, white) and amosite (1 · 700, white). X-ray is Cu— Κ α rays were used.

Figs. 8 and 9, Fig. 10 and Fig. 11, Fig. 12 and Fig. 13 are photographs of phase contrast microscopic observation of chrysotile, amosite, and crocidolite before and after infrared focused heat treatment, respectively. Figure 14 and Figure 15, Figure 16 and Figure 17, Figure 18 and Figure 19 show the powder X-rays of chrysotile, amosite, and crocidolite before and after infrared focused heat treatment, respectively. It is a diffraction pattern. In this phase contrast microscope photo, the fibrous form of asbestos is observed as a blue glow!

From these figures, it is clear that fibrous asbestos is contained in any of the samples after the infrared condensing heat treatment! / ,!

[0024] (Melting experiment 2)

A melting experiment of spray material on a flat surface was conducted.

When the asbestos spraying material applied on a flat surface using this technology is melted, the asbestos-containing spraying material with a concentration of 0.1% to several percent is mainly processed. Specifically, rock wool, vermiculite, and pearlite, which are the base materials of typical spray materials, must be melted simultaneously with asbestos. Moreover, in the processing of the asbestos-containing spray material on the assumed plane, the above-mentioned crystal growth apparatus cannot be used as it is because of restrictions on the shape of the apparatus.

Therefore, in this experiment, only a reflecting mirror was prepared, and a rock unole (thickness of about 15 mm) and vermiculite sprayed on a concrete plate (60 mm x 300 mm x 30 Omm) and an iron plate (5 mm x 300 mm x 300 mm). (Thickness of about 5 mm) and pearlite (thickness of about 5 mm) were melted.

[0025] FIG. 20 is a diagram schematically showing the method used, in which 1 is a reflecting mirror, 2 is a halogen lamp, 3 is a spraying material, and 4 is , Concrete plate or iron plate, 5 is the molten part.

The reflector used was a spheroidal mirror made of brass and gold-plated on the mirror surface. The focal length for the spheroid was 50 mm, the major axis was 65 mm, the minor axis was 60 mm, and the minor axis to major axis ratio was 0.92. The halogen lamp used was a flat filament (JCS 100V-650WCC manufactured by Usio Electric Co., Ltd.) with a power of 650W. Halogen lamp The center of the lament was located at one focal point inside the reflector, and the reflector was placed so that the other focal point was on the surface of the spray material. The power supply was the 100V'15A power supply used in the crystal growth apparatus.

Each result is shown below.

(1) Rock wool on concrete

The surface began to melt at about 55V, and melted and collapsed at about 70V. The irradiation time was about 30 seconds. Even when the voltage was increased to 90 V, the melted part did not increase. This means that a local melting process with a diameter of about 15 mm and a depth of about 15 mm has been achieved. Figure 21 is a cross-sectional photograph after rock wool on concrete has melted. The melted and solid ocher mass remained on the bottom and sides of the sinkhole.

(2) Vermiculite on concrete

Smoke started at about 30V, started melting at about 70V, and the melted part at about 85V boiled. The irradiation time was about 30 seconds. The melted area was about 10 mm in diameter and about 3 mm deep.

(3) Perlite on concrete

Smoke started at around 20V, started melting at around 70V, and the part melted at around 75V boiled. The irradiation time was about 30 seconds. The melted area was about 10 mm in diameter and about 3 mm deep.

(4) Rock wool on iron plate

The surface started to melt at about 50V, and melted and collapsed at about 60V. The irradiation time was about 30 seconds. Even when the voltage was increased to 90 V, the melted part did not increase. The melted area was about 20 mm in diameter and about 16 mm in depth. The temperature of the iron plate after the experiment remained at room temperature.

(5) Vermiculite on iron plate

Smoke rose at about 30V, and the voltage increased to 95V. The irradiation time was about 30 seconds. The temperature of the iron plate after the experiment rose to about 50 ° C!

(6) Perlite on iron plate

Smoke rose at about 20V, and the power increased to 95V. Irradiation time is 3 It was about 0 seconds. The temperature of the iron plate after the experiment rose to about 50 ° C!

[0027] From the experimental results of (1), (2), (3), and (4) above, rock wool on concrete, vermiculite, pearlite, and rock wool on iron plates can be melted by local heating with infrared rays. It became clear that power.

From the experimental results of (4), (5) and (6) above, it can be seen that the thermal conductivity of vermiculite and pearlite is larger than that of rock wool, and the thickness of the sprayed vermiculite and pearlite. Power It is thin compared to rock wool, suggesting that local heating power by infrared rays is not possible for vermiculite and pearlite on iron plates.

[0028] (Melting experiment 3)

The surface of the concrete or iron plate may be exposed during the spraying material melting process. In addition, the experiment was performed to irradiate the concrete surface and the iron plate surface with infrared rays in the same way as the melting process for the spraying material described above. went.

Each result is shown below.

(7) Concrete

It started to melt at about 45V, and the part melted at about 65V boiled. After that, even if the voltage was raised to about 70V, the boiling only increased. The irradiation time was about 30 seconds. The melted area was about 10 mm in diameter and about 2 mm in depth.

(8) Iron plate

No change even if the voltage is increased to 95V. No oxidation was observed. The irradiation time was about 30 seconds. The temperature of the iron plate after the experiment rose to about 50 ° C!

[0029] From the results of (7) and (8) above, when the spray material such as rock wool on the concrete is melted by the method and apparatus of the present invention, the infrared rays should be condensed directly on the concrete surface. Even if this happens, only the surface of the concrete is forced; it only melts thinly to about 2mm, and it can be understood that it cannot melt or break to the inside of the concrete. On the other hand, in the case of an iron plate, even if infrared rays are directly collected on the surface of the iron plate, due to its good thermal conductivity, local heating cannot be performed and the irradiation energy over a relatively large area It can be seen that the steel plate cannot be melted and no alterations such as oxidation and breakage need to be considered. [0030] (Melting experiment 4)

In order to know the relationship between the lamp voltage and temperature on an iron plate that is not affected by infrared irradiation except for temperature rise, silver foil, copper oxide (CuO) powder, and iron oxide (FeO) powder were previously

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Infrared rays were irradiated using the method shown in the schematic diagram of FIG.

(9) Silver foil (0 · lmm X 15mm X 15mm)

The voltage was raised to 95V, but there was no change. It was considered that the powder did not have a glossy foil, so the reflectivity was large and the temperature did not rise.

(10) Copper oxide (CuO) powder: Melting point 1100 ° C

It started to melt at about 35V, and the whole melted at about 40V.

(11) Iron oxide (Fe 2 O 3, Fe 2 O 3) powder: both melting points about 1600 ° C

2 3 3 4

It began to turn black at about 25 V Fe O 1 which was a red powder. Changing to Fe 2 O

2 3 3 4

it is conceivable that. Melting started at about 70V, and the whole melted at about 75V.

[0031] From these experiments, it can be seen that there are cases where the melting process by the infrared condensing heating is not easy depending on the thermal conductivity or the reflectance of the target material, or! /, Or the volume.

It was confirmed that the asbestos-containing spray material targeted by the present invention is a material suitable for local heat treatment with low thermal conductivity and reflectance. In addition, it was proved that there was almost no influence from the infrared irradiation of concrete or steel sheet, which is the base material of walls, ceilings, etc., when the spray material was applied. Moreover, since the voltage at which rock wool melts is around 70V, the iron oxide melting test results show that the temperature of rock wool is 1600 ° C or higher. Therefore, when rock wool mixed with asbestos is melted, it is certain that the contained asbestos, whose melting point is said to be about 1500 ° C, is also melted when the wool is melted. It was also shown that chrysotile, crocidolite, and amosite were all easily melted by infrared rays, and the fibrous form disappeared. It became clear that it was practically possible to perform in-situ melting.

Industrial applicability

[0032] According to the method and apparatus of the present invention, asbestos can be made harmless by being attached to a wall that does not need to be peeled off from the wall or the like, and melted as it is. , Rua The application of the method and apparatus of the present invention to the asbestos treatment required when demolishing a sbestos board or asbestos-containing rock wool can be greatly expected.

Claims

The scope of the claims

[1] A method for melting asbestos, characterized in that asbestos, an asbestos-containing member, or an asbestos in an asbestos-containing member is melted by concentrating light from the light source on the asbestos or the asbestos-containing member.

2. The asbestos melting method according to claim 1, wherein the light emitting source is a light source that emits light including infrared rays.

[3] The asbestos melting method according to [1], wherein the asbestos or asbestos-containing member is applied or sprayed on a plane, a curved surface, or a polyhedral surface.

[4] An apparatus for melting asbestos, an asbestos-containing member, or an asbestos in an asbestos-containing member, comprising a light source and a means for condensing the light emitted from the light source on the asbestos or the asbestos-containing member An asbestos melting apparatus characterized by that.

5. The best melting apparatus according to claim 4, wherein the light source is an infrared irradiation lamp.

6. The asbestos melting apparatus according to claim 4, wherein the condensing means is a spheroid mirror, and is a reflecting mirror capable of condensing light from a light source in a dot shape. .

7. The asbestos melting apparatus according to claim 4, wherein the condensing means is a reflecting mirror capable of condensing light from a light source in a linear shape.

[8] Any one of claims 4 to 7, characterized in that it is an apparatus for melting asbestos, an asbestos-containing member or asbestos in an asbestos-containing member applied or sprayed on a plane, a curved surface, or a polyhedron. 1. The asbestos melting device according to item 1.