JPS62237984A - Waste materials treatment for asbestos-containing substance - Google Patents

Abstract

PURPOSE:To facilitate waste materials treatment, by adding a proper melting aid and a proper additive to the materials containing an asbestos fiber to melt the resulting mixture at high temp. and vitrifying the same or converting the same to a substance having a crystal structure other than asbestos. CONSTITUTION:Asbestos-containing waste 1 being a melting object is weighed to be thrown in a grinder 4a from a hopper 3 and ground to a proper particle size to be guided to a mixer 5. A melting aid and an additive of kinds and amounts corresponding to the material quality of the waste are added to the waste materials from melting aid storage bins 6a, 6b and additive storage bins 7a, 7b to be mixed therewith according to a wet system. The asbestos waste after mixing is transferred by a conveyor 8a to be thrown in a melting furnace 9 and melted under heating in the furnace 9 and injected in a mold 11 from the discharge nozzle provided to the lower end part of said furnace 9 and subsequently gradually cooled and solidified by a cooling mechanism 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for disposing of asbestos fibers and other articles containing asbestos.

[Prior art and its problems]

Asbestos is resistant to heat and friction, and has excellent heat insulating properties, so extremely large amounts of asbestos have been used in building materials, friction materials, sealing materials, heat insulating materials, and the like.

However, as questions have been raised that the asbestos used in these products is suspected of being a carcinogen, the handling of these asbestos products in Japan is also becoming regulated by law. [For example, Ministry of Labor Ordinance No. 39 of September 30, 1971 and Ministry of Labor Ordinance No. 2 of September 30, 1975 (revised)
Regulations based on the Ordinance on Prevention of Hazards from Specified Chemical Substances, etc. (Specialized Regulations) under No. 6] In addition, these regulations are not limited to Japan; in the United States, regulations have been proposed for a longer time than in Japan, and have recently been implemented. was approved by the U.S. Environmental Protection Agency (EP) in January 1986.
A) proposes a strict regulatory policy that ``reduces the use of asbestos year by year and completely bans its use in 10 years.''

In response to this situation, glass fibers that can replace asbestos have been developed, and as a result, the types and quantities of products that use asbestos are decreasing dramatically.

However, even if strict regulations regarding asbestos such as those mentioned above are established and implemented, they will only guarantee future safety, and will not be effective when disposing of asbestos products that have been used in large quantities in the past. There are no guarantees regarding safety.

In the past, the amount of products produced using asbestos (including those used in building products, plants, etc.) was enormous. In this case, waste containing extremely large amounts of asbestos will inevitably be generated, making the above-mentioned danger all the more urgent.

Considering the risk of cancer mentioned above, it is likely that considerable care and measures will be required to dispose of these products, but at present, asbestos products cannot be used in other buildings without taking special protective measures when disposing of them. The reality is that the parts are destroyed together with machines.

Considering the flow of regulations under current laws and regulations, it is expected that the disposal methods for disposing of these asbestos products will naturally become a problem, but at present in Japan, there are no plans to dismantle buildings or dismantle plant equipment. However, there are no laws or regulations that cover the handling of asbestos products for disposal, and only some local governments do so when demolishing buildings that use asbestos-containing materials. It only requires workers to "wear dust masks" and to "sprinkle water on asbestos materials" and "install vinyl curtains inside buildings" to prevent asbestos fibers from scattering at work sites. be.

[Purpose of the invention]

The present invention is intended to address these circumstances, and its purpose is to melt waste containing asbestos fibers at high temperature and convert it into vitrification or into a substance with a crystal structure other than asbestos. The present invention aims to provide a method for disposing of asbestos-containing materials, which is characterized by converting them into stable and harmless inorganic solids.

Another object of the present invention is to provide a new waste treatment method that can reduce the volume of asbestos-containing waste and facilitate its disposal.

Furthermore, another object of the present invention is that it can be applied to all asbestos-containing materials to be disposed of, ranging from high to low-level asbestos content, Moreover, even if the material to be treated is inorganic or organic, it can be disposed of very easily by using appropriate melting aids and additives. The purpose is to provide a method.

Still another object of the present invention is to enable inorganic solids obtained by high-temperature melting to be used as materials for civil engineering and construction, thereby making it possible to utilize resources effectively. The present invention aims to provide a method for disposing of asbestos-containing materials.

[Key points of the invention]

The present invention involves mixing asbestos-containing waste with a melting aid, then putting it into a melting kiln, and heating the waste at a high temperature in the melting kiln to melt and solidify the waste in its entirety. The main point is to do so.

〔Example〕

In the present invention, a melting aid is mixed with waste containing asbestos to be treated, and the mixture is put into a melting furnace and heated at high temperature, thereby melting and assimilating the entire amount of waste while melting. This is a method for disposing of asbestos-containing materials.

In addition, "asbestos" as used in the present invention is not limited to its type, and generally includes warm asbestos 84M g 3S t 209 blue asbestos.
NaFe (Sins)z・FeSiO3 ■ Hornblende Ca (Mg, Fe) 3 (S i 03
) a■ Orthogonal asbestos (F e, Mg) S i 03
means.

In addition, the asbestos-containing waste referred to in the present invention refers to molded insulation materials such as asbestos insulation materials, diatomaceous earth insulation materials, basic magnesium carbonate insulation materials, perlite insulation materials, and vermiculite insulation materials, as well as powdered or water-mixed materials thereof. Heat insulation materials, heat insulation exterior coating materials mixed with other powders, asbestos fibers, asbestos threads,
Asbestos string, asbestos rope, asbestos tube, asbestos ribbon, asbestos cloth, textile products and processed products thereof, gaskets, packing, brake linings, clutch facings,
Refers to asbestos paper, asbestos board, asbestos cement products, asbestos calcium silicate board, sprayed asbestos, asbestos tile, etc.

Further, the melting aid used in the present invention refers to a boric acid compound, a phosphorus compound, a silicate compound, a carbonate compound, an alkaline earth metal hydroxide, or a cullet of a melt-solidified product generated in the process of carrying out the present invention.

Examples of boric acid compounds include BzOi (boric anhydride), H3BO3 (boric acid), and Na2B40?・10H20 (borax) Na2B40?・5HzO (dehydrated borax) Ca B4O
7' 6 H2O (calcium borate) Na ZCa
2 (B4O7) 3' 18H20 (polonite calcite) Phosphoric acid compounds include P2O, (e4 pentoxide) Hs po a (phosphoric acid) NaHPOn' 12H20 (secondary sodium phosphate) C
a3 (PO4)! (Third calcium phosphate) As a silicate compound, 1Oz Na2S t2o5 (sodium silicate) Na 2S
i O3 (sodium silicate) Na4S i O4 (sodium silicate) K2Si40. (Potassium silicate) KzSizOs (Potassium silicate) K2S > 03 (Potassium silicate) Examples of the carbonate compound include Na2COa (sodium carbonate), KgCO3 (potassium carbonate), Li2CO1+ (lithium carbonate), and the like.

Further, in order to further enhance the volume reduction effect, it is desirable to add a melting aid such as a melting promoter, an oxidizing agent, a reducing agent, etc. together with the melting aid.

As the above-mentioned melting promoter, As a melt accelerator BaCC1+ (barium carbonate) 13asO4 (barium sulfate) as an oxidizing agent NaN0i (sodium nitrate) KNOs (potassium nitrate) as a reducing agent C (carbon) SnO (stannic oxide) SnC#z・2H20 (Stannic chloride) can be mentioned respectively.

The above-mentioned "melting aids" such as boric acid compounds have the function of lowering the melting point when asbestos-containing waste is melted, whereas "melting accelerators" such as barium carbonate reduce the melting time. This is effective for shortening the time.

Hereinafter, specific embodiments of the present invention will be described with reference to charts of a waste treatment apparatus.

The asbestos-containing waste 1 to be melted is measured using a measuring device 2a.
After weighing, the pulverizer 194 a
After being pulverized to an appropriate particle size, it is guided to a mixer 5.

In addition, if the asbestos-containing waste to be melted was obtained under water sprinkling during demolition, it should be weighed using a weighing device 2b that is specialized for weighing waste containing water, and then transferred to a wet crusher. 4b and then guided to the mixer 5.

6a and 6b are storage bottles for melting aids, 7a and 7b are storage bottles for additives, and the type and amount of these were selected and weighed as appropriate depending on the material of the waste to be melted. Thereafter, it is added to the asbestos-containing waste 1 in the mixer 5 and wet-mixed.

The asbestos-containing waste 1 mixed with a melting aid and optionally additives by the mixer 5 is transferred to a melting furnace 9 by a conveyor 8a.

Note that it is desirable to remove moisture from the asbestos-containing waste 1 by providing a heating drying device 8b such as a heater on the conveyor 8a.

Further, as the heater used in the heating drying device 8b, resistance heating, microwave heating, heating wire heating, far infrared heating, etc. may be used; You can also try it out.

Although most of the water content of the pulverized asbestos-containing waste 1 transferred to the heating drying device 8b is removed during the transfer process, it cannot be denied that some water remains. While falling from the input port 9b of the melting furnace 9, it can be brought into an almost completely dry state by high-temperature gas and radiant heat.

The pulverized asbestos-containing waste 1 is charged into the melting furnace 9 continuously or intermittently according to the treatment schedule.

The melting point of the asbestos-containing waste 1 placed in the melting furnace 9 can be lowered when a melting aid is added to the asbestos-containing waste 1 than when it is melted alone.

The melting furnace 9 can be heated by arc heating, resistance heating, heating using the Joule heat generated by passing electricity through the waste itself, high frequency heating, or a combination of these methods, but depending on the work. From the point of view of avoiding complications, electric heating can be said to be the best method.

During melting in the melting kiln 9, asbestos-containing waste, melting aid,
Decomposed products such as H20:O□:CO□ are generated in the additive, and a part of these decomposed products may be discharged from the inlet 9b of the melting furnace 9 together with the powder of the dried material before melting. The discharged gas and powder exchange heat with the moisture-containing waste transported by the conveyor 8a, contributing to the temperature rise and drying of the waste, and a part of the discharged powder is It is collected here.

Note that the gas discharged here is sucked into the dust collector 10 through the duct 8C.

The melting kiln 9 is different from a normal glass kiln because it melts various materials, and requires corrosion resistance rather than heat resistance. Therefore, it is recommended to use fused quartz blocks that are resistant to electrocast refractories and borosilicate glass melting. is necessary.

The asbestos-containing waste 1 melted in the melting kiln 9 is injected into the mold 11 from a discharge nozzle provided at the lower end, and then slowly cooled and solidified by the cooling mechanism 12.

The molded product after solidification is removed from the mold 11, stored in a waste storage container such as a tank or drum, and stored at a predetermined storage location.

Example 1 Asbestos cloth (chrysoquil asbestos) 100 parts Maximum usage temperature 480°C Melting temperature
1.520°C sand
30 parts 1.10 parts of the above mixture
A solidified product was obtained by heating at 0°C. The solidified product obtained is 5
The volume of the vitrified material was 0 cc, and the volume reduction ratio was as small as 1/2. Further, the dissolution rate with respect to water was 10-hg/C-day.

Example 2 Calcium silicate heat insulating material 100 parts Maximum operating temperature: 650°C Melting temperature: 1.550°C Bulk specific gravity: 0.2 Boron Sand
25 parts sodium carbonate
10 parts The mixture having the above composition was heated at 1.000"C to obtain a solidified product. The obtained solidified product was a vitrified product of 50 cc, and the volume reduction ratio was extremely small at 1/10. I was able to make it happen.

In addition, the dissolution rate for water is 10-6 g/cJ-da
It was called y.

〔Effect of the invention〕

The effects of the present invention obtained by the above method are as follows.

(1) Asbestos-containing materials produced through the disposal of buildings, etc. can be vitrified by heating and melting, or converted into stable and harmless inorganic solids that have a crystal structure other than asbestos. It is possible to easily prevent harm caused by scattering asbestos fibers to other places.

(2) The volume of treated waste is the same as that before treatment.
Since the volume can be reduced and solidified to an extremely superior ratio of 1/2 to 1/10 compared to G, the waste and storage area for the processed material can be stored in a small space.

(3) Asbestos-containing materials that are disposed of are completely irreversible by themselves, but by forming them after disposal, the inorganic solids can be reused as civil engineering and construction materials, etc. This can have excellent side effects of preventing pollution and reusing resources.

(4) Although the shape of asbestos-containing materials before disposal (volume reduction and solidification) is extremely amorphous, it is possible to form them into a specific shape during volume reduction and solidification. This has the excellent effect that it can be freely molded into a shape that is suitable for later use.

(5) The range of asbestos content of asbestos-containing materials to be disposed of can be applied to all ranges from high to low levels.

(6) The material to be disposed of may be inorganic or organic, and the melting temperature can be adjusted freely by using melting aids and additives added as necessary. can do.

[Brief explanation of drawings]

The figure is a schematic chart diagram illustrating an apparatus for carrying out the invention. 1... Asbestos-containing waste, 2a, 2b... Measuring instrument, 3
...Hopper, 4a...Crusher, 4b...Wet grinder, 5...Mixer, 5a, 5b...Storage bottle for melting aid, 7a, 7b...Storage bottle for additive material , 8a・
...Conveyor, 8b...Drying device, 9...Melting kiln, 9b...Input port Patent applicant Meisei Kogyo Co., Ltd. Procedures Neho Authorized Letter (Method) June 25, 1986 Commissioner of the Patent Office Michibu Uga, Patent Application No. 80894, filed in 1986, 2, Name of the invention: Method for disposing of asbestos-containing materials 3, Relationship with the case of the person making the amendment Patent applicant address: 1-8-5 Kyomachibori, Nishi-ku, Osaka Name: Myojo Kogyo Co., Ltd. Representative: Shinta Tomiki Department 4, Agent address: 2-7-4-6, Kanda Tsukasa-cho, Chiyoda-ku, Tokyo Subject of amendment: Specification and drawings 7 attached to the application, Attached statement of correction regarding the content of the amendment Correction as follows: The following part of the attached details of the application is corrected as follows. (1) Brief description of the drawings starting from line 5 on page 18 of the specification: ``4. Brief description of the drawings Figure 1 is a schematic chart showing an apparatus for carrying out the present invention.'' I am corrected. (2) Please write the drawing number on the drawing attached to the application as shown in the attached sheet.

Claims (9)

[Claims] (1) Mix a melting aid with waste containing asbestos, add additives such as a melting accelerator as necessary, and then heat the asbestos fibers at high temperature in a melting kiln to vitrify the asbestos fibers, or , a method for disposing of asbestos-containing materials, characterized by converting them into substances having a crystal structure other than asbestos. (2) The waste containing asbestos is a molded insulation material such as asbestos insulation material, diatomaceous earth insulation material, basic magnesium carbonate insulation material, calcium silicate insulation material, perlite insulation material, vermiculite insulation material, or powder or water paste of these materials. insulation material,
The method for disposing of asbestos-containing materials according to claim 1, which is a heat-insulating exterior coating material mixed with other powders. (3) The waste containing asbestos is asbestos fiber, asbestos thread, asbestos string, asbestos rope, asbestos tube, asbestos ribbon, asbestos cloth, textile products thereof, or one of these processed products,
or a mixture thereof. The method for disposing of asbestos-containing materials according to claim 1. (4) The method for disposing of asbestos-containing materials according to claim 1, wherein the asbestos-containing waste is a gasket, packing, brake lining, or clutch facing. (5) The method for disposing of asbestos-containing material according to claim 1, wherein the asbestos-containing waste is asbestos paper or asbestos board. (6) The method for disposing of asbestos-containing materials according to claim 1, wherein the asbestos-containing waste is an asbestos-cement product, an asbestos-calcium silicate board, or an asbestos tile. (7) The method for disposing of asbestos-containing material according to claim 1, wherein the asbestos-containing waste is sprayed asbestos. (8) The melting aid to be added is either a boric acid compound, a phosphoric acid compound, a silicate compound, a carbonic acid compound, an alkaline earth metal hydroxide, or a cullet of the melt-solidified product generated in the process of carrying out the method of the present invention. 2. The method for disposing of asbestos-containing materials according to claim 1, which is a combination of these. (9) Additives to be added together with the melting aid include melting promoters such as barium carbonate and barium sulfate, sodium nitrate,
Disposal of asbestos-containing material as set forth in claim 1, which is any one or a combination of oxidizing agents such as potassium nitrate, reducing agents such as carbon, stannous oxide, stannous chloride, graphite, zinc, etc. Processing method.