JP4121389B2 - Production method of hydrothermal solidified product using incinerated ash as main raw material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to garbage incineration ash and coal incineration ashFor the production method of hydrothermal solidified products using incinerated ash likeIt is related.
[0002]
BACKGROUND OF THE INVENTION
  In recent years, with high consumption and high industrialization, a large amount of waste is emitted from all over the country. Waste is roughly classified into household waste and industrial waste. Of these, household waste is collected by the local government, of which combustible waste is incinerated, and incombustible waste is mainly disposed of in landfills.
[0003]
  Even if garbage is incinerated, it is not completely lost, but incinerator ash (main ash and fly ash) remains in the incinerator. Since the incineration ash contains mostly hazardous substances such as heavy metals and dioxins, local governments are worried about its disposal.
[0004]
  On the other hand, laws and regulations have been developed for environmental conservation, triggered by environmental destruction caused by illegal dumping of industrial waste. As part of this, waste containing hazardous substances must be managed and maintained at the final disposal site, and has been dealt with by creating a final disposal site in the mountainous areas.
[0005]
  However, problems such as the contamination of groundwater and rivers due to incomplete leakage prevention at the disposal site and the generation of bad odors frequently occur. For this reason, there are strong opposition from the residents in the final disposal site development plan, and it is difficult to create a new one. Of course, the existing final disposal site is almost full.
[0006]
  Under such a critical situation, attempts have been made in various places to solidify and detoxify the waste that is defined as “Moegara” in the environmental standards, such as incinerated ash. For example, solidification by cement, solidification by asphalt, solidification by rapid cooling after melting at high temperature has been attempted.
[0007]
  However, solidification with cement and solidification with asphalt are merely solidification of potato, and elution of heavy metals and dioxins cannot be prevented.DifficultyThere is a problem. In addition, the method of rapid cooling after melting at a high temperature not only increases the cost, but also cannot be formed into various shapes, so it can be said that it is far from commercialization.
[0008]
  Raw materials having no safety problems such as incinerated ash that does not contain heavy metals or dioxins, or ceramic waste powder can be solidified and used as building materials. However, the conventional ones have the problem of low strength and poor appearance, and the fact is that commercial operation is not progressing.
The
[0009]
[Prior art]
  By the way, water is converted to high-temperature and high-pressure steam due to geothermal and geological pressures inside the earth, and it is thought that rocks are generated by the hydration action of this high-temperature and high-pressure steam and geological pressure. . This is called hydrothermal diagenesis.
[0010]
  An attempt was made to solidify the incinerated ash into a stone by artificially creating the same action as the hydrothermal diagenesis reaction (that is, a pseudo hydrothermal diagenesis reaction, hereinafter abbreviated as “hydrothermal reaction”). It is made. When the incineration ash is solidified by a hydrothermal reaction, the incineration ash is converted into a stone, and the elution of heavy metals can be suppressed below the standard value of the soil environment standard set by the Environment Agency.
[0011]
  Yamazaki, one of the inventors of the present application, has been working on solidification of incinerated ash using hydrothermal reaction for a long time, and also proposed a technology that uses hydrothermal action to decompose and detoxify dioxins. (Patent Document 1).
[0012]
  Furthermore, research and improvement have been made from various aspects regarding solidification technology of incineration ash and the like using hydrothermal reaction. For example, Patent Document 2 and Patent Document 3 describe that incinerated ash is formed in the presence of a calcium component and then solidified by autoclaving.
[0013]
  Patent Document 4 describes that a so-called hot press apparatus in which a press unit is provided with a heating unit and a steam supply unit performs molding and hydrothermal diagenesis simultaneously.
[0014]
  In the case of a method using a hot press apparatus as in Patent Document 4, it is difficult to control the temperature and pressure, and it is difficult to make the quality uniform and increase the size of the product. On the other hand, it can be said that the method of separately performing the pressure molding step and the hydrothermal reaction step as in Patent Documents 2 and 3 is practical because it is easy to increase the size and quality of the product.
[0015]
[Patent Document 1]
Japanese Patent No. 2758541
[Patent Document 2]
JP 54-128477 A
[Patent Document 3]
Japanese Patent No. 2748206
[Patent Document 4]
JP-A-7-256227
[0016]
[Problems to be solved by the invention]
  As already described, incineration ash is increasing, and solidification technology using hydrothermal reaction is expected as an effective treatment method for incineration ash that is exceeding its storage capacity. However, as expected, it is not yet ready for commercial operation. The reason can be considered from two aspects.
[0017]
  One is that technology for efficiently producing hydrothermal solidified products with excellent strength has not yet been established, and the other is to improve the product value in selling hydrothermal solidified products as products. This is not sufficient, and therefore, the cost concern (ie, the concern that it cannot be sold even if it is made) has not been dispelled.
[0018]
  This invention is made in view of such a present condition, and makes it a subject to raise the waste disposal technique using a hydrothermal reaction to the level which can be commercialized.
[0019]
[Means for Solving the Problems]
  The inventors of the present application have made efforts to improve the strength, safety, production efficiency, and commercial value of hydrothermal solidified products.
The experiment was repeated and research was repeated. And based on the knowledge obtained from these experiment and research, it came to complete this invention.
[0020]
  The present inventionA method for producing a hydrothermal solidified product, which comprises incinerated ash as a main component and is cosmetically treated with a cosmetic aid, comprising the steps of: This is a basic configuration comprising a step of forming an intermediate by pressure molding, and a step of placing the intermediate in an autoclave and exposing it to saturated steam under pressure to solidify by a hydrothermal reaction.
[0021]
  In the first aspect of the present invention, in the basic configuration, one or more kinds of granular natural stones are used as the cosmetic aid, and the granular natural stones are mixed evenly in the intermediate or intermediate. It is mixed only in the surface layer of the body, and after the intermediate is solidified, the surface is polished so as to increase the exposed area of the granular natural stone.
[0022]
  In the invention of claim 2, in the basic configuration, the cosmetic aid is in the form of powder or flakes, and the cosmetic aid is provided with a cosmetic aid by pressure molding in a state where the cosmetic aid is coated on the surface of the kneaded product. An intermediate is formed and then the intermediate is solidified in an autoclave.
[0023]
  In the invention of claim 3,In the basic configuration, natural stone powder or inorganic dye or inorganic pigment is used as the cosmetic aid, and a first kneaded product in which no cosmetic aid is mixed and a second kneaded product in which a cosmetic aid is mixed; And the first kneaded product and the second kneaded product are subjected to pressure molding in a state where the second kneaded product is on the surface side, so that the surface portion is formed of the second kneaded product. An intermediate is made, and then the intermediate of the laminated structure is solidified by an autoclave.
[0024]
  In the invention of claim 4, natural stone powder or an inorganic dye or an inorganic pigment is used as the cosmetic aid, and a plurality of kneaded products having different colors are made using the cosmetic aid. These kneaded materials are laminated in multiple layers and pressure-molded to produce an intermediate, which is solidified by an autoclave.
[0025]
[0026]
DETAILED DESCRIPTION OF THE INVENTION
  Next, specific embodiments of the present invention will be described with reference to the drawings.
[0027]
  (1). Outline of the process (Figure 1)
  FIG. 1 is a process diagram showing a specific flow of a production method (hydrothermal solidification method) according to the present invention. First, an outline of the process will be described based on this figure, and then details of each process will be described. .
[0028]
  (1) -1. mainoriginalFee
  In the present invention, various incinerations classified as “Moegara” in the environmental standardsAsh mainCan be used as a fee. Moegara includes various incineration ash, such as incineration ash from municipal waste, incineration ash from organic sludge, and coal ash emitted from thermal power plants.The
[0029]
  (1) -2.Foreign body removalLast
  The raw material carried into the treatment facility from the incineration site is stocked, and then foreign substances such as metals, organic matter, and stones are removed as pretreatment. The removal of the foreign matter can be performed using, for example, a coarse sieve. It can also be removed manually. When removing the magnetic material, a magnet may be used. Note that small inorganic substances such as sand may be mixed in to some extent.
[0030]
  (1) -3.MoistureAdjustment
Incineration ash removed from the incinerator is often accumulated in warehouses. Because of this,
In many cases, moisture is absorbed by absorbing moisture or by spraying water to prevent scattering. Therefore, the water content is adjusted so that the water content is 5 to 10 wt%. In the drying process, a hot air type dryer or the like may be used, and if there is no environmental problem, natural heat drying is also possible. When the raw material is sufficiently dried, a drying step is not necessary.
[0031]
  (1) -4.Grinding and particle sizeAdjustment
  The dried raw material is pulverized using a pulverizer such as a ball mill, and is further passed through a sieve to adjust the particle size. Particle size is 30-200meshIt is preferable to adjust so as to pass through the sieve (details will be described later).).
[0032]
  (1) -5.Mixing of auxiliary materialsTogether
  An auxiliary material is mixed with the main raw material whose particle size has been adjusted. Auxiliary materials include curing aids that help cure and improve aesthetics.BeautyThere are auxiliary materials and other auxiliary materials. HardAs chemical aids, Portland cement (hereinafter simply referred to as “cement”), slaked lime (Ca (OH))₂), Calcium bicarbonate (Ca (HCO_Three)₂), Ca-containing materials such as waste glass powder. One of these may be used, or a plurality of types may be mixed.
[0033]
  BeautyNatural stones and inorganic pigments are suitable for the auxiliary material from the viewpoint of availability and cost. Various natural stones such as feldspar, marble, granite, granite and olivine can be used. This makes it possible to produce a product that looks very similar to natural stone such as marble or granite.
[0034]
  These natural stones may be pulverized to a particle size of about 0.5 to 5 mm and mixed with the main raw material. For example, Bengala can be used as the inorganic pigment.
[0035]
  BeautyAidForm ofAs a state, only a single kind of natural stone, multiple natural stones, only a single inorganic dye, multiple inorganic dyes, single or multiple kindsNatural stone andSingle or plural inorganic dyes can be arbitrarily selected.
[0036]
  (1) -6.Commercialization assistantMaterial
  In commercialization, aesthetics are an important factor. No matter how good the strength is, if it looks bad, the commercial value will be significantly reduced. Therefore, for the purpose of making the surface beautifulBeautyUse aids.
[0037]
[0038]
  In the case of natural stone, a mixing amount of about 5 to 15 wt% is preferable, and in the case of an inorganic pigment, a mixing amount of about 3 to 5 wt% is preferable. A small amount of inorganic pigment is enoughIs wearingThis is because the color effect is high. Whether it is natural stone or inorganic pigment, the strength of the product will not decrease if an appropriate amount is mixed.
[0039]
  (1) -7.Adding and mixing moistureTraining
  Water is added to the mixture of raw material and auxiliary material and kneaded. As water, alkaline aqueous solution, especially caustic soda water (H₂O, NaOH) are preferred. A particularly preferable concentration of NaOH is about 2 mol / L (ph is 8.5 or more), and a particularly preferable water content is 20 wt% with respect to the whole.
[0040]
  (1) -8.Pressurizationform
  The kneaded product is formed into a desired form using a pressure forming apparatus (press machine) equipped with a forming die. In this case, it is preferable to warm the kneaded product to a temperature of 80 to 100 ° C. in order to increase the strength of the product. The pressurizing pressure is, for example, 10 to 30 MPa. In order to promote compression, it is preferable to apply pressure while applying vibration of about 320 Hz.
[0041]
  (1) -9.Hydrothermal reactionMeet
  The intermediate formed by the pressure molding machine is put into an autoclave and exposed to high-temperature and high-pressure saturated steam to cause a hydrothermal reaction. Thereby, the intermediate body becomes a hydrothermal solidified product solidified in a stone shape.
[0042]
  The temperature of the saturated steam is 150 to 220 ° C., the pressure is 1.6 to 2.2 Mpa, and the time of exposure to the steam (reaction time) is preferably about 8 to 12 hours (note that the reaction time may be rephrased as the autoclave curing time) good.).
[0043]
  (1) -10.Hydrothermal solidificationGoods
  The manufactured hydrothermal solidified product can be used for various applications including civil engineering and building materials. In particular, it is expected as a substitute for cement products, concrete products, stones, and ceramic products. Needless to say, the shape, size, color, pattern, etc. may be set according to the application.
[0044]
  (2).Analysis of each process (Figs. 2-14)
  Next, details of experiments, analysis, and the like for each step will be described with reference to FIGS. The strength measurement is based on JIS. Unless otherwise specified, “water” means fresh water, and the reaction pressure was about 1.8 to 2 MPa.
[0045]
  (2) -1. mainoriginalFee
  The composition of municipal waste incineration ash is shown in FIG. It is considered that the large amount of CaO is derived from the paper glossy material. As can be seen from the differences between the samples, the composition of the incinerated ash varies considerably depending on the type of garbage.
[0046]
  (2) -2.Relationship between raw material particle size and strengthPerson in charge
  The relationship between the particle size of the raw material and the tensile strength of the hydrothermal solidified product is shown in the graph of FIG. Conditions are as shown in the figure. From FIG. 3, it can be seen that the tensile strength tends to increase as the particle size decreases.
[0047]
  In addition, as a special point, it is mentioned that the case where the particle size of 50 to 200 mesh is mixed is superior to the case where the particle size is about 200 mesh. The detailed mechanism of why this phenomenon occurs has not been fully clarified, but it is presumed that when particles with different particle sizes are mixed, the deposition density of the mixture increases and the hydrothermal reaction works strongly. .
[0048]
  (2) -3. ViceBlast furnace slag / melting furnace slurry as raw materialG
  A large amount of slag is generated from the blast furnace for iron making, and this treatment is also a problem. Therefore, blast furnace slag was mixed in the incinerated ash as the main raw material and hydrothermally solidified, and the strength was measured. The result is shown in the graph of FIG. The conditions are as follows. Add 15wt% cement as a hardening aid. An aqueous NaOH solution (2 moI / L) was added as water to the mixture by 20 wt%. The molding pressure is 10 MPa. Hydrothermal reaction at 150 ° C for 10 hours. The blast furnace slag had a particle size of about 0.5-5 mm.
[0049]
  From FIG. 4, it was found that although a slight decrease in strength was observed due to the mixing of blast furnace slag, the strength decrease as a product was negligible if the mixing rate was about 20 wt% or less. Therefore, when incinerated ash is used as the main raw material, it is possible to use both blast furnace slag as a secondary raw material and hydrothermally treat both together to make it stone.
[0050]
  In addition, the intensity | strength showed the tendency to fall gradually with the increase in the addition amount of blast furnace slag. Therefore, if the strength of the hydrothermal solidified product is not required, blast furnace slag can be added by 20 wt% or more (for example, 30 wt%).The
[0051]
  By the way, as an incinerator capable of preventing the generation of dioxins, melting furnaces that incinerate garbage at a high temperature of about 1000 to 1200 ° C. are becoming widespread. In this melting furnace, there is left a brittle called vitrified melting furnace slag, which is also subject to regulation as industrial waste. In the present invention, this melting furnace slag can be used as a main raw material and commercialized as well as detoxified.
[0052]
  (2) -4.Relationship with curing aidsPerson in charge
  The graph of FIG. 5 shows the relationship between the mixing ratio and the tensile strength when cement is used as a curing aid and when slaked lime is used. The molding conditions are as shown in the figure (the conditions are slightly different between the two).The). From this figure, it can be understood that the tensile strength increases with the amount of cement mixed in.
  When the mixing ratio of cement increases, the cost increases accordingly, and the processing amount of the incinerated ash that is the original processing target decreases. Therefore, when using cement in commercial operations, it can be said that the amount used is preferably as small as possible while ensuring the strength required for the product.
[0053]
  From this figure, it can be seen that when slaked lime is used as a curing aid, the strength increases as the mixing ratio increases, and the strength improvement rate decreases at the point where the mixing ratio of slaked lime is 10 wt%.
[0054]
  Even if the usage amount of slaked lime increases, it leads to an increase in cost. Therefore, in the commercial operation, the range of 5 to 10 wt% is considered to be appropriate as in the case of cement.
[0055]
  In addition, calcium bicarbonate (Ca (HCO_Three)₂) Can be used, but experiments have shown that calcium bicarbonate is slightly less effective than cement and slaked lime.
[0056]
  Waste glass powder (glass fine powder) can also be used as a curing aid. In the graph of FIG. 6, the case where only cement is mixed as a hardening aid and the case where only waste glass powder is used are compared. From this figure, it can be understood that waste glass powder also has a hardening accelerating action comparable to cement, and that the effect does not increase much even if it exceeds 20 wt%. Therefore, when waste glass powder is used, the mixing ratio is considered to be 5 to 20 wt%.
[0057]
  Since waste glass powder is originally a waste, it is considered suitable as a curing aid from the cost aspect. In the experiment which became the base of FIG. 6, the tensile strength is low because the molding pressure is as low as 5 MPa. However, the strength can be dramatically improved by pressure molding at a pressure of 10 MPa or more.
[0058]
  (2) -5.Shadow of moisture content and NaOH concentrationsound
  In the graph of FIG. 7, the experimental result about the relationship between a moisture content and tensile strength is shown. The purpose of this experiment was to grasp only the relationship between moisture and strength, no curing aid was used, and fresh water was used as the water. The molding conditions are as shown in the figure.
[0059]
  From this figure, it can be seen that the intensity peaks when the water content is 20 wt%. That is, 20 wt% is most suitable. Of course, the moisture content may vary to some extent, and it is understood that there is no problem in practicality if it is 15 to 25 wt%.
[0060]
  The graph of FIG. 8 shows the relationship between the NaOH concentration and the tensile strength. Experiments were performed under different reaction conditions. According to FIG. 8, the strength is improved by adding NaOH, and the strength rapidly increases until the concentration is 2 mol / L.IsSlowing down
Can be seen to decline. Accordingly, the concentration of NaOH is most preferably 2 mol / L, and it is considered that the range of 1 to 3 mol / L is practical.
[0061]
  (2) -6.Relationship between molding pressure and strengthPerson in charge
The graph of FIG. 9 shows the relationship between molding pressure and strength. Conditions are as shown in the figure. In the graph (A), in order to avoid the influence of other conditions, fresh water is used as moisture and no curing aid is used. Graph (B) shows a case where cement is mixed as a curing aid.
[0062]
  From FIG. 9, it can be seen that the tensile strength increases as the pressurizing pressure increases, the strength increase rate differs between 20 MPa and 30 MPa, and the high tensile strength even at low molding pressure due to the mixing of the curing aid. It can be seen that can be secured.
[0063]
  Theoretically, the higher the molding pressure, the better. However, as the size of the hydrothermal solidified product increases, the pressure molding machine needs a huge capacity. Therefore, it can be said that 10 to 30 MPa is practical in combination with other conditions.
[0064]
  (2) -7.Relationship between pressurization temperature and strengthPerson in charge
  The graph of FIG. 10 shows the relationship between the pressing temperature and the tensile strength when the kneaded material is pressure-formed with a press device. Each condition is as described in the figure. From FIG. 10, it can be confirmed that when the temperature of the kneaded product is 80 ° C. and exceeds 80 ° C., the tensile strength of the product rapidly increases.
[0065]
  Although the exact mechanism of why the temperature of the kneaded product during pressure molding is related to the strength of the product has not been elucidated, the fluidity of the raw material particles suddenly increases when the temperature exceeds 80 ° C. It is assumed that the distribution becomes uniform, and as a result, the hydrothermal reaction in the subsequent process occurs homogeneously inside the raw material.
[0066]
  (2) -8.Relationship between hydrothermal reaction conditions and strengthPerson in charge
  The graph in FIG. 11A shows the relationship between the hydrothermal reaction temperature and the tensile strength. From FIG. 11 (A), the strength increases with temperature up to 150 ° C, the tensile strength peaks between 150 and 200 ° C, and reaches 250 ° C.RejectionIt can be seen that the strength decreases. Other conditions are as indicated in the figure.
[0067]
  By the way, when the raw material is turned into a stone by a hydrothermal reaction, quartz, calcite, cement hydrate, tobermorite (Tobermorite: Ca)._Five(OH)₂Si₆0₁₆4H₂0) etc. are generated. Of these, tobermorite is known to contribute to the improvement of mechanical properties.
[0068]
  Therefore, when the X-ray analysis pattern analysis of the generated sample was performed, the generation of tobermorite crystals was confirmed in the range of about 150 to 200 ° C., but the generation of tobermorite could not be confirmed at 250 ° C. The relationship between the reaction temperature and the production of tobermorite coincides with the relationship between the temperature and the intensity shown in FIG.
[0069]
  In the graph of FIG. 11 (B), the relationship between the hydrothermal reaction time (reaction curing time) and the tensile strength is shown. From FIG. 11 (B), the strength increases with increasing time until about 20 hours, the rate of improvement in strength decreases after about 8 hours, and the strength increases in the range of 8 to 20 hours. And after 20 hours, it turned out that intensity | strength falls on the contrary. Other conditions are the same as in (A).
[0070]
  The X-ray analysis pattern was also examined for the relationship between the amount of curing time and the generation of tobermorite, but it was also found that the generation of tobermorite was activated in the range of 8 to 20 hours. Considering production efficiency and quality maintenance, it is generally preferable that the time is 4 to 10 hours, more preferably 6 to 10 hours. Of course, curing up to 20 hours is possible, but exceeding 20 hours is not preferable.
[0071]
  Thus, in the hydrothermal reaction, the reaction temperature and the reaction time are closely intertwined, and in the temperature region of 150 to 200 ° C. and in the time region of 8 to 20 hours, the particlesButDensificationTheIt was clarified that the bond strength was the highest.
[0072]
  Meanwhile, high-temperature and high-pressure steam has a function of bonding particles, but also has a function of decomposing chemical substances to a molecular level. Attempts have been made to decompose and detoxify dioxins and PCBs using this decomposition function. Also in the hydrothermal reaction, there is a region where the reaction temperature and time are intertwined closely and the hydration action is superior to the decomposition action, and this appears to be the result shown in FIG.
[0073]
  (2) -9.Heavy metal elution and dioxin harmlessConversion
  A hydrothermal synthetic rock produced using incineration ash collected in an incinerator at a household waste incineration plant as a main material was crushed to a particle size of 0.5 to 5 mm, and was stipulated in Environmental Agency Notification Nos. 13 and 46 According to the method, a heavy metal dissolution test was conducted. The heavy metal content originally contained in the main raw material was as shown in the second row of the graph of FIG. 12, and the elution rate was as shown in FIG.
[0074]
  The conditions for the hydrothermal reaction are as follows.That is,CementThe5 wt%,Slaked limeThe10 wt%EachAdditionAndAdd 20wt% NaOH aqueous solution with 2mol / L concentration to the mixtureAnd thenPressurized pressure is 20MPaMet.
[0075]
  In FIG. 12, the judgment values set by the Environment Agency are listed as safety standards for landfill materials and soils. From the comparison with this, the hydrothermal solidified product according to the present invention greatly clears the environmental judgment standards. I can understand that. Therefore, it can be said that the hydrothermal solidified product (artificial stone) according to the present invention has safety that can be replaced with cement products, stone products, and the like.
[0076]
  The incineration ash at the garbage incineration plant is roughly divided into main ash collected at the bottom of the furnace and fly ash collected by the dust collector, and dioxin is contained in both (generally contained in fly ash in large quantities). Have.). Then, hydrothermal solidified products were produced using main ash and fly ash as separate raw materials, and the solidified products were pulverized to measure the dioxin elution amount. The results are shown in the graph of FIG.
[0077]
  From FIG. 13, it can be understood that the dioxins are almost harmless through the hydrothermal reaction. This point is consistent with Patent Document 1. In addition, fly ash may contain a considerable amount of chlorine. Then, in the hydrothermal reaction step, chlorine and NaOHButReaction may cause NaCl crystals to precipitate on the solidified product. In order to prevent this point, the fly ash should be washed with water.
[0078]
  (2) -10.Relationship between size and strength of solidified productPerson in charge
  Commercial operation becomes difficult if large products cannot be manufactured. Therefore, an experiment was conducted on how the size of the hydrothermal solidified product affects the strength. A cylindrical sample having a diameter of 105 mm and a height of 80 mm as a large sample and a small sample having a diameter of 30 mm and a height of 20 mm were manufactured under the same conditions, and the tensile strengths of the two were compared.
[0079]
  FIG. 14 is a graph comparing the tensile strengths of the two. The reaction conditions are as indicated in the figure. As can be understood from this figure, it can be understood that the hydrothermal reaction penetrates to the inside regardless of the size of the solidified product. It can also be seen that the reaction time is not related to the size.
.
[0080]
  Moreover, about the large sample, although the core part was cut out and the tensile strength was compared about each of a surface layer part and a core part, the difference in intensity | strength was not seen by both. The fact that the hydrothermal reaction penetrates to the core regardless of the size opens up the way to commercialize large materials such as revetment blocks and wave-dissipating blocks, and promotes the treatment of incineration ash. It can greatly contribute to.
[0081]
  (2) -11.MatoMe
  As can be understood from the above points, in order to ensure the quality (particularly strength) of hydrothermal solidified products, the type and amount of curing aid, the type and amount of moisture, molding temperature, molding pressure, hydrothermal The temperature, pressure and time factors for the reaction are closely related.
[0082]
  Then, the inventors of the present application adopt the configuration described in the claims as a point for realizing the commercial operation by repeating the experiment, analysis and research as described above for each of these elements.
[0083]
  BookEmbodimentOne of the features of the hydrothermal solidified product is that it has good dimensional accuracy. That is, in the case of a baked product, the shrinkage varies considerably depending on various conditions, so the dimensions are uneven and the product yield is not as high as 80%, for example. Book against thisEmbodimentProduct shrinkageButConstantExtremeHigh yield can be secured. Thus, commercialization to various articles | goods is anticipated by dimensional accuracy being high, and lightweight and high intensity | strength.
[0084]
  (3). Solidification equipment and basic process(FIGS. 15 to 21)
  nextThe figureBased on the drawings below 15Examples of solidification equipment and basic processesexplain. NaParts that overlap with the above description are omitted as much as possible.
[0085]
  (3) -1.Overview
  First, an outline of equipment and processes will be described with reference to FIG. Should be processedmainThe raw material A is transported from a waste discharge source such as the garbage incinerator 1 to a solidification facility by a truck 2 and stocked in an appropriate yard. If the solidification processing equipment is installed in parallel with the garbage incineration plant 1, the transportation is naturally not necessary. In the transport, it is preferable to use a steel plate container or a thick rubber container bag from the viewpoint of preventing scattering and easy handling.
[0086]
  The solidification processing equipment in this example ismainA hopper 3 into which the raw material A is charged, a preliminary crusher 4, a coarse sieve machine 5 for removing foreign matter, a dryer 6, a ball mill 7 for pulverization, a fine sieve machine 8 for particle size adjustment, an agitator 9 for mixing auxiliary materials, A kneader 10 for adding water to the mixture to form a kneaded product, a pressure molding machine (press device) 11 for molding into a predetermined shape, and an autoclave 12 for performing a hydrothermal reaction are provided. The sieves 5 and 8 may be of a reciprocating type or a rotating drum type.
[0087]
  Between the hopper 3 and the pressure molding machine 11, raw materials and the like are sent to the next process by a conveying means such as a belt conveyor 13 or a screw conveyor 14. Further, the portion from the hopper 3 to the kneader 10 is sealed by surrounding it with a steel plate so that powders of raw materials and the like are not scattered outside.
[0088]
  As already mentioned,mainSince the raw material A often absorbs water and is agglomerated, it passes through the coarse sieve 5As expectedCrush to a suitable size (for example, a size of gravel) with the crusher 4. Although the rotary blade type preliminary crusher 4 is used in the figure, other crushers such as a roller crusher and a reciprocating crusher may be employed.
[0089]
  The dryer 6 can employ a hot air type or the like. In order to promote uniform drying, a stirring blade 6a is provided. A rotary drum dryer can also be used. As a pulverization means, a large number of steel balls inside the rotating drum (it can be replaced with stone rollers)TheThe ball mill 7 is generally used, but other mills such as a vertical mill, or a milling mill type may be used.
[0090]
  As already mentioned,mainThe particle size of the raw material A is preferably mixed within a certain range. For this purpose, for example, sieves with different eye roughness (for example, in the order of 30, 50, 100, and 200 meshes in order from the top) may be arranged and those received by each sieve may be mixed.
[0091]
  After pulverizing so that a considerable ratio becomes 100 mesh or less by a ball mill, particles with various particle diameters were mixed even when applied to a 30-50 mesh sieve, for example.mainRaw material A can be obtained. Needless to say, the sieving machine is not limited to a reciprocating type, and a drum type can also be used.
[0092]
  In the stirrer 9mainThe raw material A and the auxiliary material are homogeneously mixed to form a powdery mixture B. The agitator 9 shown in the figure uses a horizontal type in which the rotation axis of the stirring blade is horizontal, but a vertical type in which the axis of the stirring blade is in a vertical posture may be used. Of course, it is also possible to use a stirring device having another structure.
[0093]
  Made of natural stoneCosmetic aid FWhen the auxiliary material is non-powder like this, it can be pulverized with the ball mill 7 together with the raw material. In this case, when the main raw material A and the auxiliary material are completely mixed in the pulverization step, the mixing step using a stirrer is not necessarily required.
[0094]
  A caustic soda aqueous solution is sent from the tank 13 to the kneader 10 by a pipe. It is considered that kneading efficiency can be improved by dripping water such as caustic soda water in a shower form from the discharge port. It is also possible to perform mixing and stirring and kneading of the auxiliary material with one apparatus.
[0095]
  In order to mold under heating, it is preferable to warm the caustic soda aqueous solution by providing a heater in the water supply path of the caustic soda aqueous solution. The temperature should be as high as possibleWhenI can say that. The tank 13 may be heated.
[0096]
  Further, instead of or in addition to heating the aqueous caustic soda solution, the kneader 10 may be provided with a heating means. An example of the heating means is shown in FIG. That is, in FIG. 16A, a steam heating type or heat transfer type heater 15 is provided on the inner periphery of the main body tank 10a of the kneading machine 10, and in FIG. 16B, a nozzle is provided inside the main body tank 10a. Hot air or hot air or steam is blown from 16.
[0097]
  As a means for heating the kneaded material C at the time of molding, for example, a heater can be incorporated in the mold, but since a large load is applied to the mold, the structure becomes complicated and the strength is increased if the heater is incorporated. Incurs a decline. On the other hand, when the kneaded material C is preheated in the kneading stage as in this example, there is an advantage that the pressure molding machine can be made a simple and robust structure.
[0098]
  (3) -2.Pressure molding machine and autoclave
  Next, the pressure molding machine 11 and the autoclave 12 will be described with reference to FIGS. 17 is a longitudinal side view of the pressure molding machine 11, FIG. 18 is a sectional view taken along line XVIII-XVIII in FIG. 17, and FIG. 19 is a sectional view showing a molding process.
[0099]
  The pressure molding machine 11 includes a main body 20 having a cradle 18 and a head 19, a molding die 24 having a cylindrical body 21, a lower plate 22, and a piston 23. The cylinder 21, the lower plate 22, and the piston 23 constitute a molding die. The piston 23 is attached to a plunger (ram) 25 that can move up and down.
It is The plunger 25 is driven by driving means such as a hydraulic cylinder provided in the head 20.
[0100]
  A horizontal hole (or a notch with an upward opening) 26 for introducing the kneaded product C is formed in the upper part of the cylindrical body 21, and the kneaded product is inserted into the horizontal hole 25 by inserting the tip of the screw conveyor 14. C can be introduced into the cylinder 21. The screw conveyor 14 can be inserted into and removed from the lateral hole 26. The piston 23 can be raised above the lateral hole 26.
[0101]
  The cylindrical body 21 can be moved up and down along a guide shaft 27 that extends between the head 20 and the cradle 18. Further, the cylinder body 21 can be moved up and down by screwing a screw shaft 29 into a nut member 28 provided on the cylinder body 21 and rotating the screw shaft 29 forward and backward with a motor. It goes without saying that other drive mechanisms such as a hydraulic cylinder may be employed instead of the screw type vertical movement mechanism. Other lifting guide means can also be employed.
[0102]
  The lower plate 22 is fixed to the cradle 18. The lower plate 22 is formed in a convex shape so that the cylindrical body 21 can be fitted (a flat plate shape may be used). A plate-shaped receiving member 30 that is in close contact with the inner surface of the cylindrical body 21 is placed on the lower plate 22.
[0103]
  Kneaded materialCIs inserted into the cylindrical body 21, the screw conveyor 14 is moved backward, the piston 23 is lowered and pressurized, and further, with respect to the entire pressure molding machine 11 or the molding die 24 by a vibrator (not shown). A minute vibration of about 320 Hz is applied. Thereby, the kneaded materialCIs formed into a block-like intermediate D.
[0104]
  When the molding is completed, the piston 23 is raised and the cylinder 21 is raised above the intermediate body D as shown in FIG. Thereby, the intermediate body D can be taken out from the pressure molding machine 11 together with the receiving member 30.
[0105]
  Since the intermediate body D is in close contact with the inner surface of the cylindrical body 21, there is a concern that the intermediate body D is lifted together with the cylindrical body 21. In this regard, for example, the cylindrical body 21 may be raised in a state where the piston 23 is in contact with the intermediate body D (not pressurized).
[0106]
  It is also preferable to apply a release agent to the inner surface of the cylinder 21. The release agent may be applied to the lower surface of the piston 23. The type of release agent may be selected according to the type of raw material. For example, oils, silicone agents, carbon powder, etc. are conceivable.
[0107]
  As shown by an alternate long and short dash line in FIG. 19B, if a movable positioning means such as a lift pin 30 for positioning the receiving member 30 on the lower plate 22 is provided, the cylinder 21 can be fitted into the receiving member 29 exactly. Therefore, it is preferable.
[0108]
  After the cylinder 21 is raised, the receiving member 30 is pulled out from the lower plate 22 and placed on, for example, a roller type conveyor 32 as shown in FIG. Then, as shown in FIG. 21, it is carried into the autoclave 12 by the conveyor 32. When the loading is completed, the lid of the autoclave 12 is closed and a hydrothermal reaction is performed for a predetermined time. by thisHydrothermal solidified product EIs manufactured. A conveyor 33 for taking in and out is also provided inside the autoclave 12.
[0109]
  According to the present inventionHydrothermal solidified product ECan be replaced with concrete products and stone products, and many of them have large dimensions. Therefore, if the intermediate D having a large size cannot be transported safely and efficiently, the commercial operation will not be realized. In this regard, when pressure molding is performed using the receiving member 30, even a large intermediate D can be safely and quickly conveyed without being out of shape.
[0110]
  The intermediate body D is not limited to being moved by the conveyor 32, but can be transported by a carriage, a forklift, or an overhead crane. Further, as a means for taking out the intermediate body D from the pressure molding machine 11, the lower plate 22 may be lowered instead of raising the cylindrical body 21. Further, the piston 23 may be pulled out above the cylinder 21 and the kneaded material C may be put into the cylinder 21.
[0111]
  (3) -3.Surface hardening by carbon dioxide injection
  In causing the hydrothermal reaction in the autoclave 12, the surface layer of the hydrothermal solidified product can be hardened by injecting carbon dioxide gas at a rate of 12 to 18% with respect to the amount of steam.
[0112]
  This is CaO, SiO contained in incineration ash₂Reacts with carbon dioxide gas, and the surface layer of the hydrothermal solidified product is hard and dense, and the calcium carbonate layerButThis is because it is formed. Weather resistance・Abrasion resistance is increased and deterioration can be remarkably suppressed.
[0113]
  (Four). First referenceExample (Fig. 22)
  According to the present inventionHydrothermal solidified productE can be set in various shapes depending on the application. In FIG.First reference as a specific exampleAn example is shown. That is, in (A),Hydrothermal solidified productFits together so that they do not slip even when E is stacked up and downFitA protrusion 35 and a recess 36 are formed.
[0114]
  By forming the protrusions 35 and the recesses on the side surfaces as indicated by the alternate long and short dash line, it is also possible to arrange the product groups side by side so that they cannot be displaced forward and backward. In addition, what is necessary is just to set it as the expansion | deployment system which can isolate | separate the side plate to the cylinder 21, when forming a protrusion and a recess in an up-and-down surface and a side surface.
[0115]
  In the example shown in (B),Hydrothermal solidified productE is formed in a block shape, and a hole 37 penetrating vertically is formed. For example, it is possible to construct a wall of a building by inserting a reinforcing bar or a metal core into the hole 37.
[0116]
  (5). No.2 ReferenceExample (Fig. 23)
  When the weight of the hydrothermally solidified product exceeds a certain level, it is preferable that the hydrothermal solidified product can be lifted by a crane for convenience of transportation and installation. Therefore, FIG.Second reference example shown inThen, so that the suspension bolt 38 can be attached,Hydrothermal solidified productA long nut 39 is embedded in E.
[0117]
  The pressure molding is performed in a state where the end face of the long nut 39 is in contact with the piston 23. The long nut 39 has a kneaded product.CThe bolt 40 is screwed in to prevent the contamination. In this case, the threaded portion of the bolt 40 is kneaded.CThe function to prevent falling out is enhanced by exposing to the surface.
[0118]
  (6).First to third embodiments(FIGS. 24 to 25)
  FIG.4-25Is a concrete means of enhancing the aesthetics of hydrothermal solidified products.EmbodimentIs shown. Figure of which24Shown in (A)First embodimentThen, the raw material such as natural stoneCosmetic aid FAre subjected to pressure molding and hydrothermal reaction. Therefore, the commercialization aid F is evenly mixed inside the product.
[0119]
  Cosmetic aid FAre exposed on the surface of the product, and this has the appearance of a natural stone and can significantly improve the value of the product.Cosmetic aid FIs granularin the case of,Since only a small part of the surface is exposed on the surface of the product, as shown by line 41 in (A),Hydrothermal solidified productPolish the surface of ECosmetic aid FIncrease the exposed area ofTo do. ThisFor example, it has a marble-like appearance, and the aesthetics can be further improved.
[0120]
  For example, in the case of a product where only one side is visible to the human eye, such as a building wall, only that side needs to be decorated. As the method, the second shown in FIG.Second embodimentThen, the kneaded material put into the mold 24COn the surface ofCosmetic aid FThe pressure molding is performed in this state.And cosmetic aid FIf the particle size ofThe surface of hydrothermal solidified product EOnly some dimensions are polishedAnd increase the exposed area of the cosmetic aid F.PowderyBeautyAuxiliary materials, scales like shells and mica piecesFlake makeupIf an auxiliary material is used, aesthetics can be improved without providing a polishing step.
[0121]
  25th shown in FIG.3 embodimentIs a technology to make up only one side. That is, in this example, the mold 24 isCosmetic aid FMixingIsFirst kneaded productC1NextOh,Cosmetic aid F2nd kneaded material mixed withC2 is charged and then pressure-molded. In this example, both kneaded materialsC1,C2 is integrated, the upper surface is the second kneaded productC2By beautyMakeupIt is.
[0122]
  When kneaded materials of different colors are laminated in multiple layers, the difference in the layers of the kneaded material appears as a pattern on the side of the product. It is also possible to add a pattern by such a method.
[0123]
  (7).3 ReferenceExample (Fig. 26)
  In FIG.Is the third referenceAn example is shown. thisreferenceExamples are for processing non-commercial waste such as resin waste, low-level radioactive material, or injection needles. First, the non-commercial waste G is solidified by some means. As this solidification means, bookEmbodimentIt may be mixed with the kneaded material according to the above and may be pressure-molded, or may be hardened with concrete or resin.
[0124]
  Then inside the moldEmbodimentKneaded materialCAbout half of the amount, then put solidified non-commercial waste G in the center and kneaded so that non-commercial waste G is hiddenCThen press-mold and waterFeverApply. As a result, the non-commercial waste G is wrapped in the hard rock-like hydrothermal solidified layer, and no harmful substances leak out.
[0125]
  Wrapped this non-commercial waste GHydrothermal solidified productE can be effectively used as a revetment material, etc., and may be accumulated in the final disposal site. Non-commercial wasteEncapsulationInstead of this, for example, it is possible to construct a civil engineering and building material having a sense of beauty and weight by encapsulating a natural stone, a concrete block, or a metal block. The thickness of the hydrothermal solidified layer is preferably 200 mm or more.
[0126]
  (8). Fourth reference example(Fig. 27)
  As described above, the hydrothermally cured product according to the present invention has an advantage that it can maintain the aesthetics such as natural stone, brick, and tile. On the other hand, the specific gravity is about 1.6 to 2.2, which is much lighter than ordinary natural stone or concrete. For this reason, it is difficult to divert as it is to a product that requires a certain specific gravity.
[0127]
  An example of how to deal with this point is shown in FIG.4th referenceIt is shown as an example. Ie this4th referenceIn the example, the hydrothermal solidified product is formed into a hollow container shape (cone shape), and concrete is placed inside it.42By pouring and solidifying, the aesthetics and weight are secured.Hydrothermal solidified productThe opening of E is plate-shapedHydrothermal solidified productE can be occluded, or if there is no problem with aestheticsConCleat42May be left exposed.
[0128]
  (9). 5th-6th reference examples(Fig. 28)
  In FIG. 28, it was applied to the wall material of the building.referenceAn example is shown. Of these, (A) is the second5 ReferenceIt is a longitudinal cross-sectional view (or plane cross-sectional view) of an example. In this example, the wall member 43 made of hydrothermally solidified product constitutes the outer surface and the inner surface of the foundation wall, and the upper and lower surfaces or the entire peripheral surface of the wall member 43 are fitted so as not to be displaced in the front-rear direction. 44 is formed.
[0129]
  Further, by using a nut 45 embedded in the same manner as in FIG. 23A, the adjacent wall member 43 is fixed by a metal fitting 46, and the inner and outer metal fittings 46 are connected by a double-cut bolt 47. . Then, concrete is poured between the inner and outer wall materials 43 to form walls.
[0130]
  On the other hand, (B)6 ReferenceIt is a plane sectional view of an example, and the wall includes an inner and outer frame 48, a wall member 43 made of hydrothermal solidification is fixed to the inner and outer frame 48 with a screw 49, and further, between the inner and outer wall members 42. Concrete 42 is poured into the space.
[0131]
  In the case of a reinforced concrete or steel-concrete building, a formwork made of wood or steel plate is used, and much effort is required to install and remove the formwork. In addition, the concrete walls that are left untouched are generally tiled to be decorated and protected.
[0132]
  In contrast to this28In this example, the outer surface of the wall can be constructed with the wall material 43 made of hydrothermal solidified product with excellent aesthetics and water resistance, so that the tile tension can be eliminated and the work of removing the concrete formwork is unnecessary. This can reduce the construction cost of concrete buildings. In addition, it is free to stretch tiles according to preference (because the hydrothermal solidified wall material has good bondability with mortar and plaster, so the tile sticking strength is also high..).
[0133]
  The hydrothermal solidified product is suitable for the wall material of such a building because its strength exceeds that of concrete and its specific gravity is smaller than that of concrete. Of course, it can also be used as an alternative to the ALC plate.
[0134]
  (Ten). Other
  The present invention can be embodied in various ways other than the above embodiment. For example, various additives can be used as long as their functions are not impaired. Also, curing aids andCosmetic aidsOtherComplement ofIt is also possible to add auxiliaries.
[0135]
  Furthermore, the application is not limited to the specific examples described above, for example, for tiles, paving materials, sight blocks, brick substitutes, gutters, etc.ofIt can be used for U-shaped materials, fishing reefs, roof tiles, figurines, park benches, etc. It is easy to embed a reinforcing bar inside.
[0136]
[Operation and effect of the invention]
  As can be understood from the above description, according to the present invention, waste such as incineration ash can be used as a raw material to efficiently treat a product with high commercial value that is excellent in strength, aesthetics, and safety. For this reason, incinerationOf ashExpedite processingRingIt is expected to contribute greatly to improving the border and preserving the national land.The
[Brief description of the drawings]
FIG. 1 is a process diagram showing a specific flow of a production method according to the present invention.
FIG. 2 is a table showing the composition of incineration ash and the like.
FIG. 3 is a graph showing the relationship between the particle size and strength of a raw material.
FIG. 4 is a graph showing a comparison of strength when blast furnace slag is mixed.
FIG. 5 is a graph showing the relationship between the addition amount of a curing aid and strength.
FIG. 6 is a graph comparing a case where cement is mixed as a hardening aid and a case where waste glass powder is mixed.
FIG. 7 is a graph showing the relationship between water addition amount and strength.
FIG. 8 is a graph showing the relationship between NaOH concentration and strength.
FIG. 9 is a graph showing the relationship between molding pressure and strength.
FIG. 10 is a graph showing the relationship between pressurization temperature and strength.
FIG. 11 is a graph showing the relationship between hydrothermal reaction temperature and time and tensile strength.
FIG. 12 is a table relating to elution and the like of heavy metals.
FIG. 13 is a graph relating to the amount of dioxin eluted.
FIG. 14 is a graph comparing strength according to product size.
FIG. 15 is a diagram illustrating an outline of specific equipment and processes.
FIG. 16 is a diagram showing an example of heating means in a kneader.
FIG. 17 is a longitudinal side view of a pressure molding machine.
18 is a cross-sectional view taken along the line XVIII-XVIII in FIG.
FIG. 19 is a cross-sectional view showing a molding process.
FIG. 20 is a view showing a state in which the intermediate body is taken out from the pressure molding machine.
FIG. 21 is a diagram showing a state in which the intermediate body is conveyed to the autoclave.
FIG. 221 referenceIt is a figure which shows an example.
FIG. 232 ReferenceIt is a figure which shows an example.
FIG. 24One embodimentAnd the secondSecond embodimentFIG.
FIG. 253 embodimentFIG.
FIG. 263 Reference examplesFIG.
FIG. 274 ReferenceIt is a figure which shows an example.
FIG. 285-6 referenceIt is a figure which shows an example.
[Explanation of symbols]
    AMain raw material
    BPowder mixture
    CKneaded material
    DIntermediate
    EHydrothermal solidified product
    F Cosmetic aids
    6 Dryer
    7 Ball mill for pulverization
    8 Screening machine for particle size adjustment
    9 Stirrer
  10 Kneading machine
  11 Pressure molding machine (press machine)
  12 Autoclave
  20 body
  24 Mold
  30 receiving member

Claims (4)

A method for producing a hydrothermal solidified product, which is mainly composed of incinerated ash and is cosmetically treated with a cosmetic aid,
A step of making a kneaded product of incinerated ash fine powder, curing aid and moisture, a step of pressing the kneaded product with a press to make an intermediate, and putting the intermediate in an autoclave and exposing to saturated steam under pressure The basic structure is provided with each step of solidifying by hydrothermal reaction ,
One or more kinds of granular natural stones are used as the cosmetic aid, and the granular natural stones are mixed evenly in the intermediate or mixed only in the surface layer of the intermediate, and After solidifying the intermediate, the surface is polished so that the exposed area of granular natural stone increases.
A method for producing hydrothermal solidified products using incinerated ash as the main raw material. A method for producing a hydrothermal solidified product, which is mainly composed of incinerated ash and is cosmetically treated with a cosmetic aid,
A step of making a kneaded product of incinerated ash fine powder, curing aid and moisture, a step of pressing the kneaded product with a press to make an intermediate, and putting the intermediate in an autoclave and exposing to saturated steam under pressure The basic structure is provided with each step of solidifying by hydrothermal reaction ,
The cosmetic aid is in the form of powder or flakes, and an intermediate with a cosmetic aid is formed by pressure molding in a state where the cosmetic aid is coated on the surface of the kneaded product, and the intermediate is then autoclaveed. Solidified,
A method for producing hydrothermal solidified products using incinerated ash as the main raw material. A method for producing a hydrothermal solidified product, which is mainly composed of incinerated ash and is cosmetically treated with a cosmetic aid,
A step of making a kneaded product of incinerated ash fine powder, curing aid and moisture, a step of pressing the kneaded product with a press to make an intermediate, and putting the intermediate in an autoclave and exposing to saturated steam under pressure The basic structure is provided with each step of solidifying by hydrothermal reaction ,
A natural stone powder or an inorganic dye or an inorganic pigment is used as the cosmetic aid, and a first kneaded product in which no cosmetic aid is mixed and a second kneaded product in which a cosmetic aid is mixed are prepared. these
The first kneaded product and the second kneaded product are pressure-molded in a state where the second kneaded product is on the surface side, thereby creating an intermediate body having a laminated structure in which the surface portion is formed of the second kneaded product. The intermediate of the laminated structure is solidified with an autoclave.
A method for producing hydrothermal solidified products using incinerated ash as the main raw material. A method for producing a hydrothermal solidified product, which is mainly composed of incinerated ash and is cosmetically treated with a cosmetic aid,
A step of making a kneaded product of incinerated ash fine powder, curing aid and moisture, a step of pressing the kneaded product with a press to make an intermediate, and putting the intermediate in an autoclave and exposing to saturated steam under pressure The basic structure is provided with each step of solidifying by hydrothermal reaction ,
Natural stone powder or inorganic dye or inorganic pigment is used as the cosmetic aid, and a plurality of kneaded materials having different colors are made using the cosmetic aid, and the plurality of kneaded materials having different colors are laminated in multiple layers. To make an intermediate by pressure molding, solidify the intermediate in an autoclave,
A method for producing hydrothermal solidified products using incinerated ash as the main raw material.

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