KR100874887B1 - Producing method carbonized lightweight aggregate using organic sludge - Google Patents

Abstract

A method of manufacturing carbonization light weight aggregate using organic sludge is provided to have an absorption and an adhesion by a carbonization surface by mixing the organic sludge and clay, molding to a predetermined shape and being fired at a high temperature under a reducing atmosphere. A method of manufacturing carbonization light weight aggregate using organic sludge comprises steps of: manufacturing a mixed material by mixing water with a mixture of clay of 90~10 weight% and the organic sludge of 10~90 weight%; molding and drying the mixed material; and being plasticized at a high temperature of 700~1100‹C in order to have a lightness, a water-absorption, an adsorption capability and a mechanical strength under a reducing atmosphere.

Description

Producing method carbonized lightweight aggregate using organic sludge}

The present invention relates to a method for producing lightweight aggregate having surface characteristics of carbonization using organic sludge, and more specifically, to form a predetermined shape by mixing organic sludge and clay including sewage sludge, purified sludge and dredged soil. The present invention relates to a method for producing carbonized lightweight aggregate using organic sludge having excellent plastic strength by absorbing and adsorbing power by a carbonized surface by high temperature baking in a reducing atmosphere.

Among organic sludges including sewage sludge, purified sludge and dredged soil, sewage sludge in urban area is composed of 75 ~ 85% water, 10 ~ 25% organic matter and 5 ~ 10% inorganic matter by weight. Such sewage sludge has been developed with a focus on the stabilization of organic matters along with the drying of moisture, covering soil regeneration by solidification, solid fuelization by carbonization, and composting by microbial decomposition.

Among the technologies using the organic sludge described above, the cover material refining technology has a feature of evaporating moisture and enveloping organic matter with a solidifying agent to prevent leakage to the outside. Depends on. Therefore, since the soil has an engineering poor quality compared to general soil, it is inevitably recycled only to low grade cover material. In addition, carbonization techniques proposed to date are modifications of carbonization techniques or activated carbon production techniques from the past, and carbonized organic sludge in the form of fine powder to produce carbon powder in the form of fine powder, and produced as it is or in the form of granules, solid fuel, The techniques were recycled into soil improvers and water treatment media. However, the carbide obtained by applying the carbonization technology is not easy to apply because it is flowed by wind and fluid in the case of fine powder form, and the fuelization of carbide not only reduces the calorific value, but also has a demand for stable use of such low-grade solid fuel. It is not enough. In addition, the carbide is not easy to recycle due to physical strength or performance problems, such as soil improver or water treatment recycle. As described above, the cover material and carbonization technologies have limitations in applying the manufactured low-quality recycled products to existing demand sources, and there is a problem in securing stable demand sources.

On the other hand, the lightweight aggregate manufacturing technology for firing organic sludge in an oxidizing atmosphere is a technique to secure the porous by the combustion of organic components at high temperature and to form a structural support by firing the inorganic material. In this technique, in order to form the overall structure of the light weight aggregate, the inorganic component of the raw material should be mostly, and the organic component is converted into a large volume of combustion gas to form pores, so only a relatively small amount is required. However, since organic sludge has much more organic matter than inorganic amount and has a large volume, in order to manufacture lightweight aggregate by firing in an oxidizing atmosphere using organic sludge, a large amount of inorganic material including clay must be supplied from the outside. This increases the size of the recycling facility, which is also a treatment facility, increasing the burden on facility and maintenance costs, and significantly increasing the cost of treating organic sludge. In addition, the lightweight aggregate manufactured as described above is limited to construction structures such as buildings because it has only light weight. Considering the characteristics of construction structures requiring high stability and durability, it is possible to replace high-grade lightweight aggregates using new materials. It is difficult to apply as aggregate.

In order to solve the above problems, the present applicant adds a separate inorganic material in addition to the low inorganic matter ratio in the organic sludge, increases the firing temperature to increase the mechanical strength of the molded body, and simultaneously fires in a reducing atmosphere, thereby reducing the weight of carbon by carbonization. The present invention has been found to have the property of absorbing, absorbing and adsorbing, and not forming voids by evaporation of organic matter, and to reduce the amount of inorganic matter added by acting as a structural support through carbonization of organic matter.

Accordingly, the first object of the present invention for solving the above problems is to carbonize having high strength of the molded body while having light weight, absorbency and adsorption using organic sludge including sewage sludge, purified sludge and dredged soil. It is to provide a method for producing aggregate.

In addition, a second object of the present invention is to provide a method for producing carbonized aggregate, which is a functional aggregate that can be used as a base material such as rooftop greening, non-point source reduction, rainwater underground penetration.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized by the means and combinations thereof indicated in the claims.

The present invention for achieving the above object, the first step of preparing a mixed raw material by mixing water in organic sludge 10 to 90% by weight, 90 to 10% by weight of clay; Forming and drying the mixed raw material in a sphere shape; And a third step of firing the molded body at a high temperature of 700 to 1100 ° C. to have light weight, absorbency, and adsorption functionality and mechanical strength in a reducing atmosphere.

The organic sludge in the first step includes sewage sludge, purified sludge and dredged soil.

In addition, the first step is characterized by improving the foaming properties and physical properties of the carbonized lightweight aggregate by adding 5 to 10 parts by weight of at least one additive selected from limestone, iron oxide, blast furnace slag and the like based on 100 parts by weight of the mixed raw material.

The second step is characterized in that it comprises a step of pre-drying the molded body in the wet state at 100 ~ 300 ℃, and firing.

The lightweight carbide aggregate obtained through the above-described manufacturing process has a specific gravity of 0.89 to 1.13 and a compressive strength of at least 10 kg / cm ² It is characterized by having a physical property of -24 kg / cm <^2> and water absorption 16-35.

According to the method for producing a light weight carbide aggregate of the present invention, it is possible to produce a light weight, absorbent, adsorptive, yet lightweight carbide aggregate having excellent mechanical strength characteristics. Therefore, the carbonized light weight aggregate manufactured by the present invention can be used directly as a lightweight aggregate or roofing soil for lightweight roofing, a carrier for filtration of non-point pollutants by rainwater, environmental aggregates for underground penetration of rainwater, landfill soil, and the like. Has the effect that can be produced by utilizing a variety of products used.

In addition, the present invention has a different effect that can achieve the resource saving and treatment effect by having an excellent product quality and a large demand in the present situation where a large amount of organic sludge is generated and difficult to treat.

In addition, the present invention can meet the demand of the functional aggregate newly required by environmental factors, and has another effect of increasing the economical efficiency of the organic sludge treatment by the high value added of recycled products.

The above objects, features, and advantages will become more apparent from the detailed description given with reference to the accompanying drawings, and as a result, those skilled in the art may easily implement the technical idea of the present invention. You can do it. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.

As shown in FIG. 1, the present invention includes a first step of preparing a mixed raw material having a constant moisture content by measuring and mixing organic sludge, clay, and water.

In the embodiment of the present invention, the organic sludge is described as an example of sewage sludge, but is not limited thereto, and may include purified sludge and dredged soil.

In the first step, water is mixed with 10 to 90% by weight of organic sludge and 90 to 10% by weight of clay to prepare a dough mixture. At this time, a preferred blending ratio of the mixture of organic sludge and clay and water is mixture 1: 0.5 to 1 part by weight of water.

 The mixing ratio of the mixture and water is not limited to the above ratio. That is, in consideration of the amount and characteristics of organic sludge, clay and inorganic additives, the raw materials are mixed smoothly, and water is added to make a proper moisture content through the dough. In addition, the proper moisture content is determined according to the characteristics of the molding machine and the molding method.

Organic sludge consists of 70 to 85% by weight of water, 10 to 25% by weight of organic matter, and 5 to 10% by weight of inorganic matter. Generally, the weight ratio of organic matter to inorganic matter is 9: 1 to 5: 5 according to the amount of inorganic matter contained in the sewage treatment plant, and the volume of organic matter is large, the density of organic matter is small and the density of inorganic matter is large. By standard, most organic matter appears.

However, studies have shown that organic materials can also be hardened when fired at a high temperature of 700 to 1100 ° C in a reducing atmosphere, and mechanical strength increases as the ratio of inorganic materials increases. In the present invention, the mixing ratio of organic matter and inorganic matter is adjusted according to the strength and degree of functionalization by carbonization. In this case, inorganic additives such as limestone, iron oxide, and blast furnace slag containing ocher may be added. The proportion of the preferred inorganic additives does not significantly change the water content of the paste. When the mixture of organic sludge and clay is 100 parts by weight, 5 to 10 parts by weight may be added.

In addition, the present invention includes a second step of molding and mixing the mixed raw material into a sphere (sphere). Since the molding method varies according to the molding machine or the molding method, and also affects the strength of the fired body after firing, the strength of the molded body should be appropriately determined according to the use of the final carbonized aggregate. At this time, the spherical molded body in the wet state is heated to a temperature of 150 ~ 300 ℃ and dried before going to the firing step can further increase the plastic strength.

In the present invention, the process of forming a limited amount of the mixed raw material to the spherical shape for the value of use as aggregate, but is not limited to this, it is well known that it can be molded in various shapes for each application.

In the present invention, the spherical shaped body is characterized in that the third step of firing in the reducing atmosphere to have lightness, absorbency, adsorption functionality and mechanical strength. The organic material is volatile organic material is volatilized in the firing of the reducing atmosphere to have a porosity, which is called carbonization. In general, carbonization technology considers sufficient volatilization, pore development, and distribution characteristics of volatile materials and has a calcination temperature of 300 to 700 ° C., which is a relatively low temperature in view of energy saving. In the present invention, a carbonized lightweight aggregate having strength and functionality was prepared by realizing porosity by organic carbonization, supporting role by carbonization component, and increasing strength by calcination of inorganic material at a high temperature range of 700 to 1100 ° C. At this time, since the strength and functionality of the light weight carbide aggregate depends on the firing temperature, an appropriate temperature should be selected according to the use of the carbonized aggregate.

Next, the configuration of the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited thereto.

In the embodiment of the present invention, after drying the organic sludge dewatering cake collected at the sewage treatment plant in Goyang-si, Gyeonggi-do, was used by grinding to an appropriate particle size. The chemical analysis values of the raw materials used are shown in Table 1.

<Table 1> Chemical Analysis of Raw Material

content(%) SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O Na ₂ O MnO P ₂ O ₅ TiO ₂ Cl total Organic sludge 31.19 17.10 7.23 12.0 1.75 2.60 0.64 1.75 14.14 0.81 0.25 99.32 clay 70.96 16.95 7.5 0.49 0.41 0.48 0.39 0.96 0.65 0.39 0.31 99.49

<Example 1>

The mixing ratio of the organic sludge and clay was mixed and molded to 9: 1 parts by weight, and dried at room temperature, and then, a lightweight carbide aggregate was prepared under a 1050 ° C firing condition in a reducing atmosphere. At this time, the performance of the produced lightweight carbide aggregates showed specific gravity 0.89, compressive strength 10kg / cm ² , and absorption rate 35%.

<Example 2>

When the mixing ratio of organic sludge and clay is mixed and molded at 7: 3 parts by weight, and the plastic mixture is calcined under the same conditions as in Example 1, the performance of the carbonized lightweight aggregate has a specific gravity of 1.01, compressive strength of 15 kg / cm ² , and an absorption rate of 21%. appear.

<Example 3>

When the mixing ratio of organic sludge and clay was mixed and molded at 5: 5 parts by weight, and fired under the same conditions as in Example 1, the performance of the lightweight carbide aggregate was 1.03, compressive strength 18kg / cm ² , and water absorption 20%. .

<Example 4>

When the mixing ratio of organic sludge and clay is mixed and molded to 3: 7 parts by weight, and the plastic mixture is calcined under the same conditions as in Example 1, the performance of the carbonized lightweight aggregate is 1.11, compressive strength is 20kg / cm ² , absorption rate is 17%. appear.

Example 5

When the mixing ratio of organic sludge and clay is mixed and molded at 1: 9 parts by weight, and fired under the same conditions as in Example 1, the performance of the carbonized lightweight aggregate has a specific gravity of 1.13, compressive strength of 24 kg / cm ² or more, and an absorption rate of 16%. Appeared.

As shown in Examples 1 to 5 described above, the organic sludge was manufactured by firing by varying the ratio of organic sludge to clay, and the carbonized lightweight aggregate using organic sludge was prepared, and specific gravity, compressive strength, and water absorption were compared.

As a result of the test, the carbonized lightweight aggregate using the organic sludge according to the present invention has a specific gravity of 0.89 to 1.13 and a compressive strength of 10 kg / cm ^{2 to} 24 kg / when 10 to 90 wt% of organic sludge and 90 to 10 wt% of clay are mixed with water. By showing the physical property value of cm <^2> and the water absorption 16-35, it was confirmed that the outstanding functionality and strength were expressed.

1 is a flow chart showing the manufacturing process of the carbonized lightweight aggregate using the organic sludge according to the present invention.

Figure 2 is a photograph of the fracture surface of the carbonized lightweight aggregate of the present invention.

Figure 3 is a photograph of the surface of the carbide light aggregate of the present invention.

Claims (8)

A first step of preparing a mixed raw material by mixing water with a mixture of 10 to 90% by weight of organic sludge and 90 to 10% by weight of clay; Forming and drying the mixed raw material; And A third step of firing the molded body at a high temperature of 700 to 1100 ° C. in a reducing atmosphere to have lightness, absorbency, and adsorption functionality and mechanical strength Method for producing a carbonized lightweight aggregate using an organic sludge containing. The method of claim 1, The organic sludge in the first step is a method for producing carbonized lightweight aggregate using organic sludge, characterized in that it comprises at least one selected from sewage sludge, purified sludge and dredged soil. The method of claim 1, The first step is to add 5 to 10 parts by weight of at least one additive selected from limestone, iron oxide, blast furnace slag and the like with respect to 100 parts by weight of the blended raw material in order to improve the foaming, absorbency, adsorption and mechanical strength of the lightweight carbide aggregate. Method for producing a carbonized lightweight aggregate using an organic sludge characterized in that. The method according to any one of claims 1 to 3, A blending ratio of organic sludge and clay and water is a method for producing a carbonized aggregate using organic sludge, characterized in that the mixture ratio is 1: 1 to 0.5 parts by weight of water. The method according to any one of claims 1 to 3, The second step is A method for producing a carbonized lightweight aggregate using organic sludge, comprising the step of pre-drying the wetted molded body at 100 to 300 ° C. The method of claim 1, The second step of the molding process is a method for producing a carbonized lightweight aggregate using organic sludge, characterized in that for molding the mixed raw material into a sphere (sphere). delete delete

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