JP2007007610A - Environment-improving material utilizing fly ash of fine coal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environment-improving material having applications widened by using fly ash of fine coal which is industrial waste and blast furnace slag which is industrial waste too as raw material and by increasing grain size. <P>SOLUTION: The environment-improving material is manufactured by mixing fly ash of fine coal, water-soluble polymer, blast furnace slag fine powder and gypsum and is granulated into a shape of cross-section of circular shape of 5 to 20 mm and length of 10 to 50 mm. Strength is lacking in a product manufactured by fly ash of fine coal and water-soluble polymer, however, when using blast furnace slag in addition to them, the porosity is increased, absorbability of liquid is increased and, by the gypsum addition, the strength is increased. As compared to cement which is much used as a solidifying agent for fly ash of fine coal, the solidification can be initiated by the use of a slight amount and a production time is shortened. As a result, the drying process can be shortened upon the product manufacture. By being granulated into larger size, the adsorption property of water and oil is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an environmental improvement material having functions such as deodorization, moisture absorption, water absorption, and lost oil absorption using pulverized coal combustion ash which is industrial waste.

  In the pulverized coal combustion boiler of the coal-fired power plant, coal ash which is pulverized coal combustion ash is generated. It is classified into fly ash (fly ash), cinder ash, and clinker ash according to the location where coal ash is generated. Fly ash is coal ash collected from the combustion gas of a pulverized coal combustion boiler by a dust collector. Cinder ash is coal ash collected by dropping when the combustion gas of a pulverized coal combustion boiler passes through an air preheater or a economizer. Clinker ash is coal ash collected by dropping onto the bottom of a pulverized coal fired boiler.

The main components of fly ash are SiO ₂ and Al ₂ O ₃ , and these two occupy 70 to 80% of the whole.
About 8 million tons of fly ash is generated as an industrial by-product annually at coal-fired power plants nationwide, and its effective use has been studied and put into practical use. The average particle diameter of pulverized coal-burned fly ash is about 25 μm, and it is difficult to handle as it is easily scattered by wind.

  Patent Document 1 discloses a method for producing a granule having an average particle size of 1.7 to 1.9 mm by mixing coal ash, a water-soluble polymer having a carboxyl group, and water, The use of hydraulic cement as the inorganic solidifying agent is described. Its uses are concrete aggregates, roadbed materials and asphalt composites.

  Patent Document 2 discloses a method of producing a granule having a particle size of 0.3 to 5 mm and an average particle size of 1 mm by mixing coal ash, a water-soluble polymer, and cement, and the use thereof is architectural. It is described as an aggregate of the material.

  Patent Document 3 discloses porous ceramic particles having a particle diameter of 1 to 6 mm obtained by foaming and curing a mixture containing coal ash and cement, and its uses are a moisture adjusting material, a deodorizing agent, and a microorganism fixing. It is described that it is made of wood, filter material, soil improvement material, and livestock bedding.

  Patent Document 4 discloses an incineration ash, a cement-based solidifying material, a pet and livestock excrement treatment material containing zeolite, and has an average particle size of 0.1 to 10 mm and a pH of 6 to 6. 12 is preferably 7-10.

  Patent Document 5 describes a method of granulating coal ash by mixing concrete, a water-soluble polymer, and an organic acid / inorganic acid.

  In Patent Document 6, a solidified body formed of a composition containing coal ash, blast furnace slag fine powder, and aggregate is used to obtain a solidified body exhibiting high strength using glass cullet as the aggregate. Is disclosed.

JP-A-8-243527 JP-A-10-296207 JP 2001-37040 A Japanese Patent Laid-Open No. 2003-23894 JP-A-10-296208 JP 2004-115291 A

  In the aforementioned Patent Documents 1 to 5, when pulverized coal combustion ash (fly ash) is used as an aggregate of a building material, a water-soluble polymer and a cement solidifying agent are used as a solidifying agent for granulation. However, since cement is a new material, it has been insufficient as an application for recycling industrial by-products (industrial waste). Furthermore, it is known that cement contains a trace amount of heavy metals such as hexavalent chromium and lead, and the problem of using this as an environmental improvement material has been pointed out.

  Further, these materials have a particle size after granulation of 2 to 3 mm, and at most 10 mm or less, and have a limit in water and oil absorption performance. There was a problem that it was crushed by the weight of livestock at some degree.

  In Patent Document 6, since cement is not used and blast furnace slag fine powder, which is industrial waste, is used as a solidifying agent for fly ash, it is a step forward as recycling, but solidification using glass cullet as an aggregate. It is intended to be used as a substitute for sand and gravel, which are aggregates of concrete products, and utilizes functions such as deodorization, moisture absorption, water absorption, and loss of oil loss, which are the characteristics of fly ash is not.

  The present invention provides an environment improving material that is widely used by using pulverized coal combustion ash (fly ash), which is industrial waste, and blast furnace slag, which is also industrial waste, as raw materials and by increasing the particle size. For the purpose.

  In order to solve the above-mentioned problems, the environmental improvement material of the present invention is a mixture of pulverized coal combustion ash, water-soluble polymer, blast furnace slag fine powder, and gypsum, a cross-sectional shape of 5 to 20 mm in a circle, and a length of 10 It is characterized by being granulated to ˜50 mm.

  Since pulverized coal combustion ash (fly ash) is porous, it is excellent in moisture and other liquid absorbability. It also exhibits latent hydraulic properties that cure by reacting with water. Furthermore, granulation is easy.

  As the water-soluble polymer, an anionic water-soluble polymer obtained from cellulose as a raw material can be used. This is a water-soluble polymer used in foods, cosmetics and medical products, and ensures the most suitable safety for use in livestock and poultry soil. In addition, the water-soluble polymer has swelling property at the time of granulation, water retention, and extrusion stability, and functions as a binder. After granulation, it also functions as a dry strength enhancing aid.

  Blast furnace slag is iron ore produced when pig iron is produced in a blast furnace. Products made with pulverized coal combustion ash and water-soluble polymer are insufficient in strength, but as a result of using blast furnace slag, the porosity increases, the liquid absorbency increases, and the addition of gypsum increases the strength. Compared with cement, which is often used as a solidifying agent for pulverized coal combustion ash, solidification starts with a small amount of use and production time is shortened. As a result, shortening of the drying process at the time of product manufacture can be realized. A comparison of the characteristics of blast furnace slag and cement is shown in Table 1.

  From the above, it can be seen that blast furnace slag is superior to cement in terms of environment, production and cost.

Gypsum (CaSO ₄ .2H ₂ O) is used to accelerate the solidification of the blast furnace slag and to increase the strength.

  The shape is 50 mm in length and 20 mm in diameter for breeding large animals such as elephants in a zoo. Moreover, it embedded in the soil at a depth of 30 cm to 1 m as a soil moisture adjusting material, and the size used when adjusting water retention and excess water was 50 mm in length and 20 mm in diameter. For other applications, the cross-sectional shape can be 5 to 20 mm, and the length can be 10 to 50 mm.

  When the diameter of the cross-sectional shape is less than 5 mm and the length is less than 10 mm, the adsorptivity of water and oil is low. When the diameter exceeds 20 mm and the length exceeds 50 mm, it becomes difficult to maintain the strength and the molding problem. The shape of the grains may be spherical, but a rolling granulator such as a bread type, drum type, or vibration type is required, making the granulation process complicated and making hard particles that are hard to collapse. Is difficult. If the extruded product is cut into a predetermined length and granulated, the process is simple and a product having a constant shape can be produced.

  By setting the pH of the pulverized coal combustion ash to 11 to 13, the pulverized coal combustion ash can be made suitable for acidic soil neutralization. Moreover, ammonia volatilization can be reduced.

  As an application of the environmental improvement material of the present invention, using its characteristics, moisture, oil adsorbent, livestock barn, bedding for deodorization of animal manure in zoo, fermentation promoter for compost production, soil It can be used for many applications such as pH adjusters, fertilizers, adsorbents such as viscera, blood, and filth in slaughterhouses.

  According to the present invention, by using pulverized coal combustion ash, which is industrial waste, and blast furnace slag, which is also industrial waste, as raw materials, and by increasing the particle size, it is possible to provide an environment improving material that has wide application. it can.

In particular, the following effects can be obtained by making the cross-sectional shape a circle of 5 to 20 mm and a length of 10 to 50 mm.
1. The pulverized coal combustion ash (fly ash) is compressed, and the absorption of moisture and oil is increased about 5 times.
2. By adding the water-soluble polymer to the granulated product, the strength is increased by the adhesion effect between the particles of the pulverized coal combustion ash and the blast furnace slag, and the absorption of the moisture oil is increased about 10 times.
3. By putting blast furnace slag into the granulated product, the strength of the granulated product is increased, and it can be used for a long period of time as a litter for large animals such as cattle and elephants.
4). The granulation can prevent pulverized coal combustion ash from being scattered.
5. It can compensate for the lack of existing bedding (sawdust, chip dust, rice husk) and reduce costs.
6). The granulated material is a granule at the time of compost production and promotes oxygen ventilation and fermentation.
7). Chip chips, sawdust, and rice husks are required for a long time (2 to 3 years) to fully ripen as compost, but pulverized coal combustion ash is pulverized at the time of compost turning into a mixture.
8). The granulated product does not break down after adsorbed by lost oil, can be easily removed, has a large amount of absorbed oil, and after incineration, only pulverized coal combustion ash remains and can be regenerated as fertilizer.
9. It can be used as an adsorbent for liquid substances such as blood and filth generated from meat, poultry processing plants, etc., and after the liquid adsorption, the water content of the solids is reduced and the processing becomes easy. The liquid adsorbate can be incinerated and used as fertilizer or again as an adsorbent.

  Moreover, by setting the pH to about 12 (11 to 13), the ammonia concentration can be reduced, and the environment inside and outside the barn and in the vicinity of the zoo can be improved. Moreover, the pulverized coal combustion ash having a pH of about 12 itself becomes a good fertilizer.

  FIG. 1 is a block diagram showing an environment improvement material manufacturing plant of the present invention. This plant includes a pulverized coal combustion ash hopper 1, a water-soluble polymer hopper 2, a blast furnace slag hopper 3, a screw granulator 4, a dryer 5, and a product hopper 6.

  First, the pulverized coal combustion ash from the pulverized coal combustion ash hopper 1, the water-soluble polymer from the water-soluble polymer hopper 2, and the blast furnace slag from the blast furnace slag hopper 3 are quantitatively charged into the granulator 4. The mixture is stirred with a screw while adding 20 to 30% by mass of water. The material is well mixed as it goes downstream of the granulator 4, and is extruded at a predetermined pressure as a stick-like viscous material by a screw at the outlet portion of the granulator 4, and is cut into a predetermined length. Become. The granular material is dried by a dryer 5 and discharged to a product hopper 6. As a result, a circle having a cross-sectional shape of 5 to 20 mm and a particle having a length of 10 to 50 mm are manufactured.

The aim of granulating into relatively large grains as in the present invention is as follows.
As an example of the use of the environmental improvement material in a relatively clean place, there is cat sand as a cat toilet used for indoor breeding at home. Large particles are less likely to adhere to the cat's body and soil the room. In addition, the deodorizing effect is high.

  When used outdoors, it is a water absorption and deodorizing material in a chicken house for broiler chickens, and a cross-sectional shape having a diameter of 5 mm and a length of about 10 mm is suitable for this. In the case of chickens, feces are excreted, but there is no urination like mammals. Therefore, the liquid adsorption amount of the granulated material may be small. However, a large number of chickens may spill water when drinking. In summer, the amount of drinking water increases, and although there is no urination, it becomes loose stool and a large amount of absorbent is generated. Conventional bedding is mainly sawdust and chip waste of about 2 mm to 10 mm, and this size is standard. In accordance with this size, the size of the environmental improvement material was also 5 to 10 mm. This size is ideal for applications handling chicken dung to promote aerobic fermentation during manure treatment.

  In the case of cows and pigs, especially in the case of milking cows (Holstein), a large amount of water is drawn, so the amount of urination is also large. For this application, a large granulated product having a diameter of 10 to 20 mm in cross section and a length of 20 to 50 mm is preferable in order to provide a large amount of absorption capacity. Similarly, in slaughterhouses, zoos, etc., the shape of large grains is most effective for the purpose of adsorbing dirt and deodorizing.

  In the excreta treatment plant, the moisture content of the processed product has various moisture contents such as moisture of 60% to 90% (mass) or more. A 20-mm diameter section and 50-mm length was ideal as a moisture adsorbent in a milk powder treatment plant.

  In order to add other admixtures (sawdust, chip waste, rice husk), etc. to manure, and to make the proper moisture content of fermentation 60%, other mixtures have low water absorption and a large amount of mixture is required. Increases odor. However, by using the granulated product of the present invention, the absorptivity was increased, and moisture was absorbed in a small amount, and the deodorizing effect was great.

  Regarding absorption of oil, depending on the amount of oil leakage, a granulated product having a diameter of 5 mm and a length of 10 mm was suitable for a small amount, and a granulated product having a diameter of 20 mm and a length of 50 mm for a large amount.

  The environmental improvement material of the present invention includes moisture, oil adsorbent, livestock barn, bedding for deodorization of animal manure in zoos, fermentation accelerator for compost production, soil pH adjuster, fertilizer, slaughterhouse It can be used in many applications such as adsorbents for viscera, blood, and filth.

It is a block diagram which shows the manufacturing plant of the environmental improvement material of this invention.

Explanation of symbols

1 Pulverized coal combustion ash hopper 2 Water-soluble polymer hopper 3 Blast furnace slag hopper 4 Granulator 5 Dryer 6 Product hopper

Claims (2)

  An environmental improvement material obtained by mixing pulverized coal combustion ash, water-soluble polymer, blast furnace slag fine powder, and gypsum, and granulating the cross-sectional shape to a circle of 5 to 20 mm and a length of 10 to 50 mm.   The environment improving material according to claim 1, wherein the pH is 11 to 13.

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