JP4994793B2 - Method and apparatus for processing asbestos-containing material - Google Patents

Description

  The present invention relates to a processing method and processing apparatus for asbestos-containing materials, and in particular, to safely and reliably detoxify asbestos-containing materials and to effectively use the fuel energy used for the detoxification processing and the asbestos after the detoxification processing. The present invention relates to a method and an apparatus.

Asbestos (natural asbestos) is a natural mineral fiber, and serpentinite chrysotile (white asbestos, Mg ₆ Si ₄ O ₁₀ (OH) ₈ ) and amphibole amosite (tea asbestos (Fe, Mg) ₇ ). There are various types such as Si ₈ O ₂₂ (OH) ₂ ] and has excellent properties such as heat resistance, chemical resistance, insulation, etc., so it is widely used in the fields of construction materials, electrical products, automobiles, household products, etc. It had been.

  However, asbestos is a very fine fiber material with a thickness of 1/5000 that of human hair, when a person inhales asbestos dust, so-called "micro needles" pierce lung cells, asbestosis, Causes serious diseases such as lung cancer and malignant mesothelioma.

  Therefore, at present, the use of asbestos is completely prohibited, and there is an urgent need to remove the asbestos used in the past in a pollution-free manner and to make it harmless.

  As a detoxification method for asbestos-containing materials such as asbestos building materials, for example, Patent Document 1 discloses a melting furnace having a heavy oil burner in which approximately the same weight of incinerated ash of general industrial waste is mixed as a solvent with asbestos waste material. The slag melted at a temperature of about 1800 ° C is taken out and solidified while supplying high-temperature air with a heat exchanger that uses the exhaust heat at a high speed, and as a non-polluting material, concrete aggregate, etc. Describes how to recycle.

  In Patent Document 2, glass powder and clay are kneaded into a waste material made of phenol resin containing asbestos, etc., and asbestos harmful to the human body is encapsulated by melting at an appropriate temperature to prevent the asbestos from scattering. An incineration disposal method for industrial waste raw materials is disclosed.

  Furthermore, in Patent Document 3, asbestos and incinerated ash are used as raw materials to obtain a sintered body in which asbestos is rendered harmless, and asbestos that can be reused as building materials such as adsorbents, tiles, bricks, and cement fillers. Detoxification processing methods are described.

  In Patent Document 4, asbestos waste material is supplied into the rotary kiln from the vicinity of the combustion means provided on the discharge port side of the rotary kiln, and the supplied asbestos waste material and cement raw material are processed by the combustion means, thereby asbestos. A method for producing cement that can be used by detoxifying waste materials has been proposed.

JP-A-8-141537 JP-A-8-187482 JP-A-9-206726 Japanese Patent No. 3680958

  However, even with the technology described in the above patent document, asbestos can be reused as a building material such as concrete aggregate, adsorbent, tile, brick, cement filler, etc., or asbestos-containing waste material can be used as a dry powder. When blowing into a cement kiln, the dry powder leaked in the middle of the process, which could threaten the safety of workers and residents in the vicinity.

  Therefore, the present invention has been made in view of the problems in the above-described conventional technology, and detoxifies the asbestos-containing material while ensuring the safety of workers and the like, and the fuel energy used for the detoxification process and the detoxification process It aims at providing the processing method and processing apparatus of an asbestos containing material which can also make effective use of the asbestos after.

  In order to achieve the above object, the present invention is a method for treating an asbestos-containing material, wherein the asbestos-containing material is pulverized to 90 μm or more and 5 mm or less, and then mixed with a liquid fuel to form a slurry. It is characterized by blowing into a cement kiln through a dedicated burner.

  And according to the present invention, by handling the asbestos-containing material in the state of slurry, it is possible to prevent the asbestos from scattering and ensure the safety of workers and the like, and the liquid fuel itself contained in the slurry burns. Thus, a high-temperature frame can be formed, and asbestos contained in the slurry can be detoxified into harmless forsterite and elastite in a short time, and can be reliably rendered harmless. Moreover, the asbestos after a detoxification process can be used effectively as a cement raw material.

  Furthermore, by making the particle size of the asbestos-containing material 90 μm or more and 5 mm or less, it is possible to prevent the asbestos from splashing to the preheater side through the kiln bottom, and asbestos-containing material is reliably processed in the cement kiln. Can do.

  The present invention also relates to a method for treating an asbestos-containing material, in which a liquid fuel is mixed with the asbestos-containing material and then pulverized to 90 μm or more and 5 mm or less, and the slurry produced by the mixed pulverization is used as a main burner or a slurry-only burner. It is characterized by blowing into a cement kiln through.

  According to the present invention, the liquid fuel is mixed with the asbestos-containing material and pulverized, so that there is no risk that the asbestos-containing dust will scatter when the asbestos-containing material is pulverized. Asbestos scattering can be prevented. As in the above invention, the asbestos after the detoxification treatment can be effectively used as a cement raw material, and the asbestos-containing material is surely contained in the cement kiln by preventing the asbestos from scattering to the preheater side through the kiln bottom. Can be processed.

  In the method for treating asbestos-containing material, the liquid fuel can be used as waste oil, and the asbestos-containing material can be treated while effectively using the waste oil.

  Moreover, in the processing method of the said asbestos containing material, the said liquid fuel can be mixed in the ratio of 20 mass% or more and 500 mass% or less with respect to the said asbestos containing material. When the mixing ratio of the liquid fuel with respect to the asbestos-containing material is less than 20% by mass, it is not preferable because there is a concern that the slurry becomes clogged with the burner piping and the chip because it becomes a high-viscosity slurry. This is not preferable because there is a concern that the kiln refractory may be damaged during landing combustion.

  Furthermore, in the processing method of the asbestos-containing material, the blowing speed of the slurry into the cement kiln can be 10 m / s or more and 50 m / s or less. When the blowing speed is less than 10 m / s, the slurry falls too far in front of the kiln (the end of the cement kiln on the opposite side of the kiln butt), so that sufficient time for dissolving asbestos cannot be taken. If it exceeds 50 m / s, there is a possibility that the slurry will land near the bottom of the kiln and burn and there is a concern of affecting the combustion pattern of a normal cement kiln, which is not preferable.

  The present invention also relates to a processing apparatus for asbestos-containing material, a slurry for mixing the asbestos-containing material into a slurry by mixing the pulverized asbestos-containing material and liquid fuel with a pulverizing means for pulverizing the asbestos-containing material into 90 μm or more and 5 mm or less. And a blowing means for blowing the slurry into a cement kiln through a main burner or a slurry dedicated burner. According to the present invention, as described above, asbestos after detoxification can be effectively used as a cement raw material without wasting combustion energy used for detoxification while ensuring the safety of workers and the like.

  Furthermore, the present invention is an asbestos-containing material processing apparatus, a mixing and pulverizing means for obtaining a slurry containing 90 μm or more and 5 mm or less of asbestos-containing material by mixing liquid fuel with the asbestos-containing material, and the slurry. And a blowing means for blowing into the cement kiln through a main burner or a slurry dedicated burner. According to this invention, it is possible to ensure the safety of workers, prevent the generation of useless combustion energy, and effectively use asbestos after detoxification.

  As described above, according to the asbestos-containing material processing method and processing apparatus according to the present invention, while ensuring the safety of workers and the like, the asbestos-containing material is harmless, and the fuel energy and the detoxifying treatment used for the detoxification treatment It becomes possible to effectively use the later asbestos.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description, a case where a non-scattering building material containing asbestos is detoxified as an asbestos-containing material will be described as an example.

  As shown in FIG. 1, the asbestos-containing material processing apparatus according to the present invention crushes the roller conveyor 2 for supplying the non-scattering building material N to the crushing machine 3 and the supplied non-scattering building material N. A pulverizer 3, a liquid fuel tank 4 for temporarily storing liquid fuel such as waste oil, and a pulverizer 5 for wet mixing and pulverizing the crushed non-scattering building material G and the liquid fuel O A fuel tank 6 for temporarily storing the slurry-like fuel S generated by the pulverizer 5, and a main burner 7 for introducing the slurry-like fuel S stored in the fuel tank 6 into the cement kiln 8; And cement kiln 8.

  Non-scattering building material N is a building material in which asbestos moldings have been removed by demolition work, etc., resulting in waste. Asbestos slate, asbestos cement boards, roof tiles, resin water pipes, automobile brake pads, These include a matrix of an acetylene cylinder, and a gasket or sealing material containing asbestos for the purpose of imparting heat insulation and insulation.

  Even when the liquid fuel O is spilled when the slurry fuel S is supplied from the pulverizer 5 to the fuel tank 6 or leaks from the fuel tank 6 or the like, the components may volatilize and the asbestos powder may be dried and scattered. Oils containing hard-to-evaporate components such as A heavy oil, B heavy oil, C heavy oil, waste lubricating oil, heavy oil sludge, vegetable oil, waste paint, and crude oil sludge From the viewpoint of ensuring safety at the time of mixing and grinding, B heavy oil, waste lubricating oil and the like having an appropriate viscosity and a high flash point are preferable.

  The crusher 3 is provided for crushing the non-scattering building material N, and a jaw crusher or the like is used.

  The pulverizer 5 is provided for wet mixing and pulverizing the coarsely crushed non-scattering building material G and the liquid fuel O, and a wet vibration mill, a medium stirring mill, or the like is used.

  Next, operation | movement of the asbestos-containing material processing apparatus 1 which has the said structure is demonstrated, referring FIG.

  The non-scattering building material N received by the cement factory from a building demolition work site or the like is supplied to the crusher 3 by the roller conveyor 2 and crushed. Here, building materials that do not contain asbestos are removed and processed separately.

  The roughly crushed non-scattering building material G is supplied to the pulverizer 5 and mixed and pulverized together with the liquid fuel O supplied from the liquid fuel tank 4. Under the present circumstances, in order to prevent scattering of asbestos in a post process and to prevent asbestos from being precipitated in the slurry, it is pulverized to a particle size of 90 μm or more and 5 mm or less. By this mixing and pulverization, a slurry-like fuel S containing fine asbestos is produced.

  The slurry fuel S is supplied to the fuel tank 6 and then blown into the cement kiln 8 through the main burner 7. In the fuel tank 6, heavy oils, waste solvent, waste toner, and the like are mixed, and the amount of combustion energy (true calorific value), fluidity (pump pumpability, viscosity), solid dispersibility of the slurry fuel S, The air content, water content, etc. may be adjusted.

  Specifically, the true calorific value of the slurry fuel S is adjusted to 2500 kcal / kg or more, in particular, 5000 kcal / kg to 8000 kcal / kg, and used as a partial replacement fuel for the main fuel in the cement kiln for cement firing. Furthermore, a slurry fuel having a true calorific value of 5000 kcal / kg or more can be used as a main fuel in a cement kiln for cement firing. Even if the true calorific value of the slurry fuel S is 2500 kcal / kg or less. If the amount of the slurry fuel is limited and the temperature and shape of the entire burner frame are maintained, the fuel can be used without any problem.

  From the viewpoint of fluidity, the viscosity (25 ° C.) of the slurry fuel S is preferably 200,000 cps or less, more preferably 10 to 50000 cps, and further preferably 500 to 10000 cps. Slurry fuels with a viscosity of 200,000 cps or less are excellent in fluidity, so that troubles such as clogging are less likely to occur during pressure feeding, and work efficiency is improved. In addition, clogging due to high viscosity in winter can be avoided.

  The slurry-like fuel S is blown as fuel from the main burner 7 of the cement kiln 8, and the slurry itself burns to form a flame (flame) reaching 1800 ° C. or higher in the cement kiln 8, and the asbestos contained in the slurry-like fuel S Is heat-treated in this flame, and in a short period of time it is detoxified to be harmless forsterite or elastite, and the heat generated by the combustion of the slurry fuel S is used to heat the non-fired product. The

  Incidentally, the slurry-like fuel S in the cement kiln 8 is blown in the same manner as in the case of blowing in liquid fuel such as heavy oil, for example, from a pipe provided in the central portion of the coal-burning burner which is the main fuel, or in the vicinity thereof, or Alternatively, pressure feeding may be performed while metering from a dedicated blowing burner installed separately from the main fuel blowing burner.

  In addition, the amount of slurry fuel S blown is adjusted in consideration of changes in the amount of heat generated, because the amount of heat generated per unit weight differs from pulverized coal generally used as the main fuel.

  In addition, in the said embodiment, although the case where the non-scattering building material N was processed was demonstrated as an example, it is also possible to process a scattering building material. In that case, various kinds of emulsions such as epoxy resin emulsions and acrylic resin emulsions, organic fixatives such as various latexes such as SBR latex and NBR latex, alkaline aqueous solutions mainly composed of silicates and glass fine particles. An anti-scattering agent such as an inorganic fixing agent such as a mixture of

  In particular, if bentonite suspension is used as an anti-scattering agent, and it is further transported and stored in a returnable container, it can be easily fluidized simply by applying vibration when the container is inverted and placed in a wet mixing and grinding machine. It is preferable because the contents can be easily discharged and silicon, which is a component of bentonite, can react with asbestos and be rendered harmless when burned in the frame of the main burner. Further, the concentration of the bentonite suspension is preferably a water slurry of about 5% by mass.

  Moreover, in the said embodiment, although the case where the non-scattering building material N was mixed and pulverized with the liquid fuel O was demonstrated, only the non-scattering building material N was previously pulverized and then mixed with the liquid fuel O to form a slurry. It may be used as fuel.

  Next, an example of particle track calculation assuming asbestos particles in a cement kiln will be described.

  Using a main burner having a tip as shown in FIG. 2, the track of the particles when asbestos particles were blown from the blowing port 1 or 2 in the figure under the following operating conditions was calculated. When blowing from the port 1, the blowing speed is set to 10 m / s. When blowing from the port 2, the blowing speed is set to 40 m in consideration of the influence of the circulating flow generated inside the swirling internal flow. / S.

[Operating conditions]
Kiln length: 83 m, kiln inner diameter (distance between opposing refractory surfaces): 4.8 m, kiln bottom O ₂ : 3.0%, secondary air temperature: 850 ° C., primary air ratio: 9.6% , Straight outward flow velocity: 159 m / s, swirl external flow velocity: 142 m / s, swirl external flow swirl angle: 37 °, fuel flow velocity: 50 m / s, fuel flow swirl angle: 10 °, swirl internal flow velocity: 142 m / s, Swivel internal flow swivel angle: 37 °

The conditions for the asbestos particle model were as follows.
(1) Particle morphology Treated as spherical particles and does not consider waste oil covering the surroundings.
(2) Physical properties of particles Specific gravity (density): 3150 kg / m ³ , specific heat: 1100 J / kg- ° C.

  Table 1 shows the results of track calculations when asbestos particles having a particle size of 90 μm (Example) and a particle size of 45 μm (Comparative Example) were blown under the above conditions.

  As shown in the table, in the examples, it can be seen that asbestos particles land on the raw material side of 20 to 60 m from the main burner, and the asbestos-containing material can be reliably processed in the cement kiln. On the other hand, in the comparative examples, it can be seen that asbestos particles may be scattered to the kiln bottom, and then may be scattered to the preheater side through the kiln bottom.

It is a flowchart which shows one Embodiment of the processing apparatus of the asbestos containing material concerning this invention. It is the schematic which shows the front-end | tip of the main burner used for the particle track calculation supposing the asbestos particle | grains in a cement kiln.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Asbestos-containing processing equipment 2 Roller conveyor 3 Crusher 4 Liquid fuel tank 5 Crusher 6 Fuel tank 7 Main burner 8 Cement kiln G Non-scattering building material (after crushing)
N Non-scattering building material (before crushing)
O Liquid fuel S Slurry fuel

Claims (7)

After pulverizing the asbestos-containing material to 90 μm or more and 5 mm or less, it is mixed with liquid fuel to form a slurry,
A method for treating an asbestos-containing material, wherein the slurry is blown into a cement kiln through a main burner or a slurry burner. After mixing liquid fuel with asbestos-containing material, pulverize to 90 to 5 mm,
A method for treating an asbestos-containing material, wherein the slurry produced by the mixing and pulverization is blown into a cement kiln through a main burner or a slurry burner.   The method for treating an asbestos-containing material according to claim 1 or 2, wherein the liquid fuel is waste oil.   The method for treating an asbestos-containing material according to claim 1, 2 or 3, wherein the liquid fuel is mixed in a proportion of 20% by mass or more and 500% by mass or less with respect to the asbestos-containing material.   The method for treating an asbestos-containing material according to any one of claims 1 to 4, wherein a speed at which the slurry is blown into the cement kiln is 10 m / s or more and 50 m / s or less. Pulverizing means for pulverizing the asbestos-containing material to 90 μm or more and 5 mm or less;
Slurrying means for mixing the pulverized asbestos-containing material and liquid fuel into a slurry;
An asbestos-containing material processing apparatus comprising: a blowing means for blowing the slurry into a cement kiln through a main burner or a slurry dedicated burner. A mixing and pulverizing means for pulverizing the asbestos-containing material while mixing the liquid fuel to obtain a slurry containing the asbestos-containing material of 90 μm or more and 5 mm or less;
An asbestos-containing material processing apparatus comprising: a blowing means for blowing the slurry into a cement kiln through a main burner or a slurry dedicated burner.

Images