KR100562169B1 - Manufacturing method of lightweight aggregate using ash from municipal and industrial solid waste incinerators - Google Patents

Abstract

The present invention relates to a method for manufacturing lightweight aggregate which is an environmentally friendly and high value-added resource using urban / industrial waste incinerators, and uses blast furnace slag, waste gypsum and organic sludge as physical reinforcements. It is made through the process of mixing, assembling and firing the same, according to the present invention provides a method that can effectively treat and utilize the waste incineration ash that was previously treated indiscriminately by landfilling and simple solidification.

Garbage, Incinerator, Lightweight Aggregate, Blast Furnace Slag, Waste Gypsum, Organic Sludge

Description

MANUFACTURING METHOD OF LIGHTWEIGHT AGGREGATE USING ASH FROM MUNICIPAL AND INDUSTRIAL SOLID WASTE INCINERATORS}

1 is a manufacturing process of the lightweight aggregate according to an embodiment of the present invention.

Figure 2 is an appearance photograph of the light weight aggregate produced by the present invention.

Figure 3 is a cross-sectional photograph of a lightweight aggregate produced by the present invention.

Figure 4 is a graph showing the concrete compressive strength mixed with lightweight aggregate produced in Japan and the lightweight aggregate produced by the present invention.

The present invention relates to a method for manufacturing lightweight aggregate using waste incineration, and more particularly, to a method for producing lightweight aggregate, which is an environmentally friendly and high added resource, using urban / industrial waste incineration and clay as main raw materials.

Urban / industrial waste incineration ash referred to in the present invention is an incineration ash discharged from municipal waste and industrial waste incineration plants, and dust contained in the bottom ash (Bottom Ash) and combustion gas discharged to the bottom of the incinerator according to the discharged portion discharged during incineration is collected. It is divided into fly ash which is removed.

Under the current waste management law, the bottom ash is mostly composed of ash and is managed as general waste due to its relatively low concentration of heavy metals, whereas fly ash is managed as designated waste because of its relatively high concentration of heavy metals.

Fly ash among incineration ashes has been newly developed or planned incinerator facilities in which incinerators are newly socially developed or planned after hazardous heavy metals such as mercury, lead and cadmium exceed the designated waste determination criteria. It is reflected in the design and finally solidified and landfilled.

In contrast, Bottom ash was buried in landfills without a separate treatment facility. However, with the controversy over the hazards of fly ash, there has been a controversy about the hazards of floorings. Recently, when floorings were found to contain harmful heavy metals such as lead, cadmium, and mercury, they were restricted. As a result, a large amount of incinerators are left intact in the Seoul metropolitan incinerator, which is a big social problem.

Some local governments allow flooring materials to be sent to other provinces for recycling into bricks, but this is problematic because flooring materials that are likely to contain heavy metals are handled without proper measures for leaching heavy metals.

As described above, in the case of flooring, controversy continues over the safe treatment method, and there is no suitable solution due to the confrontation between the incinerator-related parties.

In addition, the generation of garbage is rapidly increasing with the increase of population and the improvement of living standard, and the problem of securing and compensation of landfills for landfilling, the cost of waste disposal facilities, and the environmental pollution caused by the discharge of landfill leachate It is getting worse.

Therefore, there is an urgent need for a technology that can effectively treat such urban / industrial waste and make use of it.

Korean Patent Laid-Open Publication No. 1999-0074135 discloses an artificial light aggregate using a waste incinerator ash and stone flour sludge and a method of manufacturing the same. It has a disadvantage that it cannot handle the fly ash part which is treated as designated waste because it contains a large amount of heavy metals, and the heavy metals contained in the incineration ash can not be fixed simply by using stone sludge but also have limitations in foaming. There is a problem in the selection of additives. In addition, the high temperature firing method using only the composition is not suitable in terms of economical efficiency since sintering may be performed only for a long time.

In addition, a number of technologies have been developed and published or published by various research institutes and individuals in Korea for the manufacture of artificial aggregates using incineration ash, but most of them focus on the treatment of coal ash, paper sludge incineration ash, etc., which contain almost no harmful ingredients. It is invented as. Since these incinerators contain little harmful substances, they can also be used as cement subsidiary materials for clay replacement and other cement admixtures, so it is not economically feasible to manufacture artificial lightweight aggregates.

The present invention is to improve the problem of disposal of municipal / industrial waste incineration as described above, complete management through safe and eco-friendly recycling of urban / industrial waste incineration, which has been indiscriminately treated and managed by landfill or solidification treatment. Its purpose is to provide a useful way to do this.

In addition, the present invention uses the blast furnace slag and / or waste gypsum as a strength enhancer to improve the immobilization ability of the harmful components of the incineration ash during firing, to reduce the absorption rate, to significantly increase the crush strength, and to be organic as a gas generating component It is possible to instantaneously melt and foam by heat generation of organic materials by adding wastes, and thus provide a method for manufacturing lightweight aggregates, which have a significantly lower firing temperature, a shorter firing time, and a dense vitreous form inside than conventional lightweight aggregates. The purpose.

In addition, the present invention is to improve the composition of the raw material significantly compared to the existing method to reduce the manufacturing cost, while effectively avoiding the fusion phenomenon between the molded body during the firing of the molded body to produce a lightweight aggregate capable of smoothly continuous operation with little defects generated It is an object to provide a method.

In addition, the present invention aims to provide artificial lightweight aggregates, which are environmentally friendly and high value-added resources that can be used for various purposes by effectively using industrial by-products and industrial wastes as the main ingredients of urban / industrial waste incinerators and clays. do.

In order to achieve the object as described above, the method for producing lightweight aggregate using waste incineration ash according to the present invention is based on 50 to 90 parts by weight of waste incineration ash consisting of 50 to 90% by weight and 10 to 50% by weight of ash, clay 50 ~ Mixing 200 parts by weight with 5 to 20 parts by weight of organic sludge and 4 to 20 parts by weight of strength enhancer to produce a mixture; Kneading water to the mixture and assembling to a diameter of 5 to 13 mm to produce a molded body; Coating and drying the surface of the molded body with a coating material; And it is characterized in that it comprises the step of cooling the dried molded body in the conditions of 700 ~ 900 ℃ and calcined for 10-25 minutes at 1050 ~ 1250 ℃.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

Figure 1 is a schematic diagram of a method for producing lightweight aggregate using urban / industrial waste in accordance with an embodiment of the present invention.

In order to manufacture lightweight aggregate using urban / industrial waste according to the present invention, first, based on 100 parts by weight of urban / industrial waste incineration, 50 to 200 parts by weight of clay, 5 to 20 parts by weight of organic sludge, and 4 to 20 parts by weight of strength enhancer Mix the parts to make a mixture. Herein, the waste incineration is made of 50 to 90% by weight of flooring material and 10 to 50% by weight of fly ash.

Hereinafter, the components of the composition will be described in detail.

Urban / industrial waste incinerators used in the present invention are incinerators discharged from domestic waste and industrial waste incinerators, and are composed of 50 to 90 wt% of floor ash and 10 to 50 wt% of fly ash.

Fly ash among the incineration ash can be used as it is discharged from the incinerator. However, the bottom ash is wetted to remove dust during incineration ash treatment after combustion, and is usually discharged with a water content of about 15 to 20%, and the unburned material is selected because it contains a large amount of unburned material and metal components. After sorting the scrap metal with a magnetic separator, it is preferable to use a pulverized sheet having passed through a 25 mm sieve to 16 mesh or less.

In addition, the clay used in the present invention is preferably used as a low-grade clay pulverized to 16 mesh (600㎛) or less. The clay includes 50 to 70% by weight of SiO ₂ , 15 to 30% by weight of Al ₂ O ₃ , 5 to 10% by weight of Fe ₂ O ₃ , 0 to 5% by weight of CaO and MgO, K ₂ O 2 to 4% by weight and Na 0.5 to 4% by weight of ₂ O is contained.

The organic sludge comprises any one or more of sewage, wastewater, water purification plant, papermaking or Corex sludge. The organic sludge may be ground to 16 mesh or less after being dried, or may be used as it is in a dehydrated state. The latter method is advantageous in terms of drying cost and raw material pretreatment cost reduction. They are used as internal gas generating components and can be used if the calorific value is 2,000 dl / g or more.

As the strength enhancing material, blast furnace slag and / or waste gypsum is used. Even when blast furnace slag or waste gypsum is used alone, the strength improvement effect of the aggregate is excellent when firing, but when the two are used in combination, the effect is more remarkable. This is because it is possible to secure the molding strength during the drying process by the hydration reaction of the slag and waste gypsum, so that it is not broken when conveying the conveyor, and smooth operation is possible, and the strength of the aggregate is significantly increased during high temperature firing.

The blast furnace slag is suitable for finely pulverizing the crushed slag produced by the steel mill at 2,000 cm 2 / g or more, waste gypsum can be used as it is discharged during the production of phosphoric acid in the fertilizer plant.

Water is kneaded into the mixture thus formed and molded into a shaped body having a constant shape with a diameter of about 3 to 13 mm. It is preferable to make the shape of the said molded object spherical.

After molding the mixture prepared as described above to form a molded body, the molded body is coated on the surface using a coating material to prevent fusion between the aggregates formed during firing. It is preferable to use waste gypsum with high refractory degree as the coating material. For example, when the surface of the molded body is coated with a thickness of 100 to 300 μm using waste gypsum, since the melting point of gypsum is high at 1,450 ° C., not only the fusion phenomenon between the molded parts due to melting of the molded body surface is prevented, but also 1,000. Above ℃, waste gypsum increases its surface hardness as its properties change to type I anhydrous gypsum.

After coating the molded product in this way, the water content of the molded product is dried to be 10% or less.

The dried molded body is put in the conditions of 700 ~ 900 ℃ and calcined at 1050 ~ 1250 ℃ 10-25 minutes, then cooled to produce a lightweight aggregate.

That is, the molded product is dried and then put into a rotary kiln, and the feeding temperature at this time is preferably about 700 to 900 ° C. If the temperature is below 700 ° C, a thick oxide film is formed on the outside of the aggregate, which is disadvantageous in weight reduction, and internal melting by instantaneous heat generation may not be sufficiently achieved. On the other hand, when it is added at more than 900 ℃ due to the rapid sintering of the organic matter by the rapid heat outside the aggregate and incomplete sintering of the clay it is difficult to form the instant foaming inside the aggregate.

2 and 3 is an external photograph and a cross-sectional photograph of the lightweight aggregate produced by the present invention is shown. As shown in the photo of Figures 2 and 3, the lightweight aggregate produced by the present invention does not occur fusion between the aggregates, the inside is formed of dense glass.

As described above, the light weight aggregate manufactured by the present invention is light weight concrete products such as bricks, blocks, boundary stones, light concrete such as roof pressed concrete, deck plate concrete, roofing greening, underground parking lot roof, retaining wall backfill, etc. It can be widely used for such uses.

Next, the specific production method and the effect of the present invention through the preferred examples and comparative examples of the present invention will be described in detail.

Component and physical properties of incineration ash, clay, organic sludge and strength enhancer used as raw materials used in the embodiment of the present invention are as follows.

I. Incineration ash

The average particle diameter of incineration ash is about 250 µm for floor ash and about 75 µm for fly ash. The components of the incineration ash used in the examples of the present invention are listed in Table 1.

division SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ MgO CaO Na ₂ O K ₂ O P ₂ O ₅ Cl Urban garbage Fly ash 22.93 4.03 2.72 2.79 25.86 4.80 4.04 1.15 14.20 Flooring 32.40 11.30 5.95 1.60 12.46 2.01 0.86 3.51 3.20 Industrial garbage Fly ash 28.12 9.03 3.72 1.79 14.33 2.62 2.62 1.92 6.62 Flooring 38.29 13.30 6.95 1.23 6.80 3.23 3.23 1.10 2.34

II. clay

The chemical composition of the clay used in the present invention is shown in Table 2 below, wherein the clay has an average particle diameter of about 215 μm.

SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O Na ₂ O L.O.I. 64.67 16.89 5.99 0.16 0.89 2.19 0.20 7.52

III. Organic sludge

Table 3 shows the organic sludge moisture content, organic content, inorganic content and calorific value, and Table 4 shows the chemical composition of paper sludge and sewage sludge as organic sludge.

Kinds Moisture content (%) Organic matter content (%) Mineral content (%) Calorific Value (cal / g) Paper Sludge 79.28 13.25 7.47 3,448 Sewage sludge 83.08 10.17 6.75 3,114

Kinds SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O SO ₃ P ₂ O ₅ Sewage sludge 40.04 22.32 12.61 8.03 2.53 1.86 5.40 5.43 Paper Sludge 36.40 22.85 1.30 26.89 5.53 0.98 3.10 2.30

Ⅳ. Strength enhancers

Table 5 shows the chemical composition and physical properties of the blast furnace slag and waste gypsum used as a strength enhancer in the present invention.

division Chemical composition (part) Powder level (㎠ / g) importance SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ Ig-loss Waste gypsum 1.98 0.70 0.11 31.66 0 43.95 20.32 2,100 2.36 Blast furnace slag 34.51 17.04 0.30 42.65 6.87 0.06 0.29 3,500 2.92

Using the raw materials having the components and physical properties as described above, various examples as described below were carried out and the results were analyzed.

Example 1

100 parts by weight of clay, 20 parts by weight of sewage sludge on a dry basis, 3 parts by weight of blast furnace slag powder and 7 parts by weight of waste gypsum were mixed with respect to 100 parts by weight of municipal waste incineration ash. The municipal waste incineration consists of 90% by weight of flooring material and 10% by weight of fly ash.

In this way, each component was weighed and mixed, and water was kneaded therein, followed by molding to a diameter of 3 to 13 mm to prepare a molded body.

The molded body was coated with a thickness of 250 μm again with waste gypsum having high fire resistance to prevent fusion of aggregates at the time of firing.

After coating as described above, it is dried to have a water content of 10 parts or less of the molded product, and the dried molded product is put under the conditions of a temperature of 700 to 900 ° C, calcined at 1050 to 1,250 ° C for 10 to 25 minutes, and cooled. It was.

As a result of testing the artificial lightweight aggregate manufactured by the above process, the specific gravity was 1.34, the absorption rate was 6.8%, and the 40-ton fracture test result of the coarse aggregate based on KS F 2541 was 37%.

Example 2

With respect to 100 parts by weight of industrial waste incineration ash (70% by weight of bottom ash and 30% by weight of fly ash), 150 parts by weight of clay, 10 parts by weight of paper sludge, 10 parts by weight of blast furnace slag powder, and 5 parts by weight of waste gypsum were added to the conditions as in Example 1. As an artificial lightweight aggregate was prepared.

As a result of testing the lightweight aggregate, the specific gravity was 1.63, the absorption was 3.4%, and the fracture rate test result was 31%.

Example 3

To 100 parts by weight of urban / industrial waste incineration ash (80% by weight of floor ash and 20% by weight of fly ash), 70 parts by weight of clay, 10 parts by weight of sewage sludge, 5 parts by weight of blast furnace slag powder and 5 parts by weight of waste gypsum were added. Artificial lightweight aggregate was prepared under the same conditions.

As a result of testing the lightweight aggregate, the specific gravity was 1.48, the absorption was 6.7%, and the fracture rate test result was 35%.

Example 4

100 parts by weight of clay, 15 parts by weight of paper sludge, 5 parts by weight of blast furnace slag powder and 10 parts by weight of waste gypsum were added to 100 parts by weight of urban / industrial waste incineration ash (60% by weight of floor ash and 40% by weight of fly ash). Artificial lightweight aggregate was prepared under the conditions.

As a result of testing the lightweight aggregate, the specific gravity was 1.59, the absorption was 6.8%, and the fracture rate test result was 33%.

In Examples 1 to 4, as the incorporation rate of fly ash increases, the crushing rate tends to decrease due to the decrease in porosity, the formation of dense tissue, and the increase in specific gravity. This is because a dense sintered layer is formed on the surface before the gas is generated during manufacturing, and thus plays an important role in preventing the escape of the generated gas.

Therefore, when the fly ash having a very high heavy metal content is mixed, it may be advantageous in the case of dense sintering for self-immobilization of the heavy metal. The fly ash mixed therein plays a role.

However, in the case of fly ash containing a large amount of chlorine ions among the harmful components, it may cause an explosive evaporation effect by the generation of chlorine gas in the foam during the firing process, causing the surface of the plastic to rupture or even shatter the plastic body.

Therefore, when the chlorine ion content of the fly ash is 15% or more, it is preferable not to exceed 50 parts by weight relative to the flooring material.

In addition, it should be noted that in the firing method according to the present invention, since low melting point metals (Pb, Zn, Cd, etc.) may be partially volatilized into gas, an appropriate air pollution prevention facility must be installed to take measures for this.

The dissolution characteristics of the aggregates prepared in the above example were carried out according to the EPA method and the Korean waste process test method. Most of the heavy metals were not detected, and a small amount of Mn, Ni, and Zn was eluted, but the effect on the environment was insignificant.

Table 6 below shows the results of detecting the elution characteristics of the light weight aggregates prepared by Examples 1 to 4 by the EPA method and the Korean waste process test method, wherein the unit is ppm, and ND (Not Detected) was tested. Indicates that no results were detected.

Method division Ti Cr Mn Co Ni Cu Zn As Mo CD Pb EPA Act Example 1 ND ND 0.26 ND 1.532 ND 0.492 ND 0.703 0.023 0.156 Example 2 ND ND 0.35 ND 1.283 ND 0.232 ND ND ND ND Example 3 ND ND 0.43 ND ND ND ND ND ND ND ND Example 4 ND ND 0.45 ND 1.890 ND 0.506 ND ND 0.012 0.013 Waste Process Test Method Example 1 ND ND 0.28 ND 1.060 ND 0.284 ND ND ND ND Example 2 ND ND 0.31 ND 1.070 ND 0.125 ND ND ND ND Example 3 ND ND ND ND 0.890 ND ND ND ND ND ND Example 4 ND ND ND ND ND ND 0.346 ND ND ND 0.234

In order to grasp the degree of quality characteristics of the lightweight aggregate obtained in the above example, the quality test of the crushed stone, structural lightweight aggregates imported from Germany, Spain and Japan, and the results are shown in Table 7.

division importance Absorption rate (part) 40ton crushed value (part) broken stone 2.62 1.78 19 Made in Germany 1.34 12.3 39 Spain 1.58 11.8 35 Made in Japan 1.63 8.8 33

As can be seen from Table 7, it can be confirmed that the light weight aggregate manufactured by the above embodiment according to the present invention has almost the same quality in terms of absorption rate and strength as compared to the imported light weight aggregate.

In addition, in order to evaluate the applicability of the lightweight aggregate manufactured according to the present invention to a lightweight concrete product, by selecting the aggregate with the same specific gravity produced by the present invention and the aggregate produced by the present invention, the composition of the same size as shown in Table 8 Lightweight concrete specimens were prepared at the compounding ratio, and the compressive strength test was performed. The results are shown in Table 8 and FIG. 4.

division Aggregate Maximum Dimensions (mm) W / C (part) AE water reducing agent (part) W (㎏ / ㎥) Weight compounding (㎏ / ㎥) Compressive strength (㎏f / ㎠) C S G 3 days 7 days 28 days Comparative Example (Made in Japan) 13 50 0.3% of cement weight 185 370 780 599 157 244 322 Invention (Example 2) 178 263 356

Concrete mixed with lightweight aggregate manufactured by the present invention increased the initial weight of 3 days and 7 days by 13% and 8%, respectively, compared to the concrete containing imported lightweight aggregates at the compressive strength of 28 days. It showed 11% higher strength than the mixed concrete.

Therefore, the light weight aggregate according to the present invention is capable of expressing more than the equivalent physical properties compared to the imported light weight aggregate is expected to be utilized in large quantities as a lightweight concrete and lightweight concrete secondary products. Moreover, considering that the current state of the production of light weight aggregates in the country are all imported and used at a high price in foreign countries, the import substitution effect by the supply of low-cost products according to the present invention is very large in the future.

The present invention is an environmentally friendly mass processing method of urban / industrial waste incineration materials that have been processed indiscriminately by conventional landfilling and simple solidification, and the final product is discharged into light aggregates, which are high value-added products, and can be utilized as construction materials and various hazardous substances. By sintering and melt-fixing, there is an effect that can solve the environmental technical challenges of environmental harm.

In addition, it is possible to provide an artificial lightweight aggregate that can be used for a variety of economical and economical use is possible with a low firing temperature, a short firing time, a dense glassy form within the conventional lightweight aggregate and economical.

Moreover, the lightweight aggregate according to the present invention has a very large import substitution effect of the lightweight aggregate, which is currently dependent on imports, and can greatly contribute to the development of urban / industrial waste incineration ash processing and recycling.

As described above, the present invention relates to a method for producing lightweight aggregate by mixing organic sludge and strength enhancer with urban / industrial waste incinerator and clay as the main raw materials, without departing from the spirit and scope of the present invention. Many modifications and variations are possible in the

Claims (4)

50 to 200 parts by weight of clay, 50 to 200 parts by weight of clay, 5 to 20 parts by weight of organic sludge and 4 to 20 parts by weight of strength enhancer are mixed with respect to 100 parts by weight of waste incineration consisting of 50 to 90% by weight of flooring material and 10 to 50% by weight of ash. Generating; Kneading water to the mixture and assembling to a diameter of 5 to 13 mm to produce a molded body; Coating and drying the surface of the molded body with a coating material; And Putting the dried molded body under the condition of 700 to 900 ° C., calcining at 1050 to 1250 ° C. for 10 to 25 minutes, and then cooling; Light aggregate production method using a waste incineration ash comprising a. The method of claim 1, wherein the organic sludge comprises any one or two or more of sewage, wastewater, water purification plant, paper sludge, and corex sludge. The method of claim 1, wherein the strength enhancer is a blast furnace slag or waste gypsum alone or a mixture of blast furnace slag and waste gypsum, characterized in that the light aggregate production method using waste incineration ash. The method of claim 1, wherein the coating material is a light aggregate production method using waste incinerator, characterized in that the waste gypsum.

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