KR101967231B1 - Manufacturing method for recycled aggregate using sludge and concrete products thereof - Google Patents

Abstract

The present invention relates to a recycled aggregate forming method using sludge and a concrete block using the same. The recycled aggregate forming method using sludge includes: a mixed sludge forming step of forming mixed sludge by mixing various kinds of sludge at a predetermined ratio; a mixture evaporating step of evaporating moisture contained in the mixed sludge by mixing industrial byproducts having exothermic feature with the mixed sludge; a drying and evaporating step of drying the mixed sludge, from which moisture is evaporated in the mixture evaporating step, at 100-200°C; and a sintering and dehydrating step of sintering the mixed sludge, dried in the drying and evaporation step, at 650-1,000°C. Various kinds of sludge in the mixture sludge forming step include centrifugal concrete sludge, ready-mixed concrete sludge, stone sludge, and sewage sludge. The present invention is expected to improve the durability and strength of a concrete block using a recycled aggregate by removing moisture, a chemical material, or an organic material contained in sludge in phases to form the recycled aggregate.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for forming a recycled aggregate using sludge and a concrete block using the same,

The present invention relates to a method of forming a recycled aggregate using sludge and a concrete block using the same, and more particularly, to a method of forming recycled aggregate by stepwise processing centrifugal force concrete sludge or the like designated as industrial waste and a concrete block .

In general, various kinds of sludge designated as industrial wastes are treated by landfill or incineration, and the research and development of recycling technology is required due to the cost of treatment and environmental pollution.

Among the waste sludge designated as industrial waste, concrete sludge is generated during the manufacturing process and cleaning process of concrete. Sand and gravel of the waste generated in the concrete manufacturing process are used again as aggregate in the concrete manufacturing process. However, concrete sludge mixed with water, cement and admixture finally present in sludge type has PH higher than 11 because it has low strength of cement and low formability even when mixed with general cement, so it is designated as construction waste. It is buried and treated. As concrete sludge is buried, processing cost and transportation cost are increased, and the economic burden of concrete manufacturers is increasing.

Among these concrete sludge, there are centrifugal concrete sludge and remicon sludge. Centrifugal concrete sludge is generated during the manufacturing process of concrete according to the centrifugal compaction method. Remicon sludge is generated in the remicon factory or remicon vehicle. Most of the remicon sludge is cement and the powder degree is about 3,000 ㎠ / g. However, the centrifugal concrete sludge has a high strength due to the nature of the product, which contains 4,000 ~ 100,000 ㎠ / g of admixture material and is relatively difficult to recycle .

In addition to concrete sludge, sewage sludge (sewage sludge) and stone sludge containing stone due to stone processing are the final products that are generated in the water treatment process, and most of them are treated by landfill or incineration.

It is required to introduce recycling technology of various kinds of sludge as a cause of cost and environmental pollution due to the treatment of the sludge.

Korean Patent Registration No. 10-0321820 (Registered Date: Oct. 10, 2002) Korean Patent Registration No. 10-0798893 (registered date: Jan. 22, 2008) Korean Patent Registration No. 10-0947926 (Registered Date: Mar. 9, 2010)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for forming recycled aggregate by recycling various kinds of sludge treated by landfill or the like.

Another object of the present invention is to provide a method for forming a recycled aggregate having increased strength and durability when used in the production of concrete.

According to an embodiment of the present invention, there is provided a method for forming a recycled aggregate using sludge, comprising the steps of: forming a mixed sludge by mixing various types of sludge at a predetermined ratio to form a mixed sludge; mixing the industrial by- A drying step of drying the mixed sludge in which the moisture is evaporated at a temperature of 100 to 200 ° C, a sintering step of sintering the mixed sludge dried in the drying step of evaporation at 650 to 1000 ° C, And a dehydrating step.

In addition, in the mixed sludge forming step, various types of sludge may include centrifugal concrete sludge, remicon sludge, stone sludge, sewage sludge.

In addition, in the mixed sludge forming step, various types of sludge may include 40 to 60 wt% of centrifugal force concrete sludge, 15 to 25 wt% of remicon sludge, 15 to 25 wt% of stone sludge, and 5 to 15 wt% of sewage sludge .

In addition, in the mixed evaporation step, the exothermic industrial by-products may include one or more of papermaking ash, cogeneration ash, desulfurized gypsum or quicklime.

Further, in the mixed evaporation step, the exothermic industrial by-products and the mixed sludge can be mixed at a weight ratio of 1: 9.

In addition, the drying step is performed for 12 to 24 hours, and the mixed sludge dried in the drying step may have a water content of 10% or less.

In addition, the calcination dehydration step can be carried out for 12 to 24 hours.

In addition, the recycled aggregate can be formed by the above-described forming method.

Also, the concrete block can be manufactured using the recycled aggregate.

According to the method for forming recycled aggregate using the sludge of the present invention, recycle aggregate is economical and resource can be recycled because various types of sludge are mixed and recycled aggregate is used.

In addition, when the concrete product is manufactured using the recycled aggregate according to the forming method of the present invention, the strength and durability of the concrete product are improved by the effect of pore filling by the fine particles of the sludge.

In addition, since the organic matter is removed through the firing dewatering step, when the concrete product is manufactured, the strength is lowered, and no condensation or cracking is prevented.

1 is a flowchart illustrating a method of forming a recycled aggregate using sludge according to an embodiment of the present invention.
2 is a photograph before and after the firing dehydration step according to an embodiment of the present invention.
FIG. 3 is a graph comparing compressive strengths of an embodiment in which a recycled aggregate according to an embodiment of the present invention is incorporated and a comparative example.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It should be understood, however, that the embodiments according to the concepts of the present invention are not intended to be limited to any particular mode of disclosure, but rather all variations, equivalents, and alternatives falling within the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the "inclusive" or "gajida" and the terms are staking the features, numbers, steps, operations, elements, parts or geotyiji to be a combination thereof specify the presence, of one or more other features, integers , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Hereinafter, the present invention will be described in detail.

1 is a flowchart illustrating a method of forming a recycled aggregate using sludge according to an embodiment of the present invention.

Referring to FIG. 1, a method for forming a recycled aggregate using sludge according to an embodiment of the present invention includes forming a mixed sludge (S100 A mixed evaporation step (S200) of mixing the industrial byproducts having exothermic properties with the mixed sludge to evaporate water contained in the mixed sludge (S200); mixing the mixed sludge with water evaporated in the mixed evaporation step (S200) (S300), and a calcination dehydration step (S400) in which the mixed sludge dried in the dry evaporation step (S300) is calcined at 650 to 1000 占 폚.

The sludge of the present invention means a material in the form of a mud containing water and may have the same meaning as the sludge or slurry. The sludge may have a water content of 40 to 100%.

In the sludge mixing step of the present invention, various types of sludge are mixed at a certain ratio. The various kinds of sludge may include centrifugal concrete sludge, remicon sludge, stone sludge, sewage sludge.

The centrifugal force concrete sludge means sludge generated in centrifugal force concrete using centrifugal force compaction method, and the remicon sludge means sludge discharged to waste in a remicon factory or remicon vehicle. Stone sludge (stone sludge) Means sewage sludge, and sewage sludge means sludge generated in the treatment of sewage or wastewater.

In one embodiment of the present invention, the mixed sludge mixed in the sludge mixing step comprises 40 to 60 wt% of centrifugal force concrete sludge, 15 to 25 wt% of remicon sludge, 15 to 25 wt% of stone sludge, 5 to 15 wt% , Preferably 50 wt% of centrifugal concrete sludge, 20 wt% of remicon sludge, 20 wt% of stone sludge, and 10 wt% of sewage sludge.

In the present invention having the above mixing ratio, the fine particle contained in the centrifugal-force concrete sludge and the fine particle contained in the remicon sludge are mixed with each other, and thus the effect of filling the void by the fine particles in the case of using the concrete as the circulating aggregate or concrete product Thereby enhancing the strength of concrete products and recycling resources.

Specifically, the centrifugal force concrete sludge has a powder size of about 100000 cm ² / g and a relatively small particle size. When the recycled aggregate formed by containing 40 to 60 wt% of the centrifugal force concrete sludge is used in a concrete product such as a concrete block The filler effect (filler effect) is generated by the high-fine-grained fine particles, so that a high-strength concrete product can be produced. Since the remicon sludge has a relatively high particle size when compared with the centrifugal force concrete sludge having a powder degree of about 3000 to 4000 cm ² / g, it is generally generated in the production of cement, have. According to the present invention, in addition to the centrifugal-force concrete sludge and remicon sludge, the mixed sludge and the sewage sludge are mixed together to form a mixed sludge (S100), thereby securing a sufficient amount of sludge and simultaneously treating various kinds of sludge treated as waste As well as the mixed sludge which can effectively utilize the high differential properties of the centrifugal concrete sludge.

In the mixed evaporation step (S200) of the present invention, the mixed sludge formed in the mixed sludge forming step (S100) is primarily evaporated. The exothermic industrial by-products used in the mixed evaporation step (S200) may be paper ash, coke oven ash, desulfurized gypsum or quicklime. The papermaking ash refers to a kind of ash produced as a by-product in the paper making or paper making plant which processes and processes paper, the term " cogeneration ash " means a kind of ash produced as a by-product in a cogeneration power plant, It is a by-product obtained by fixing sulfur oxides released during combustion by chemical reaction. It is a byproduct in the operation of flue gas desulphurization (FGD) to remove sulfur dioxide contained in exhaust gas from coal-fired power plant. Which is a kind of gypsum. The quicklime is a material calcined of natural limestone or calcium carbonate at a temperature of 900 ° C or higher, and can be divided into light burned lime and dead burned lime depending on the application. The paper ash, coke oven ash, desulfurization gypsum or quicklime used in the present invention may be used by mixing one or more of them.

The materials are exothermic industrial by-products. In the mixed evaporation step (S200) of the present invention, the mixed sludge formed in the mixed sludge forming step (S100) is mixed with the industrial by-products to dry the mixed sludge first.

Specifically, the industrial by-product generates heat at 60 to 100 ° C when it comes into contact with water. In the present invention, since the mixed sludge has a high water content of 50 to 100%, moisture contained in the mixed sludge It is a method of drying with heat generated from by-products.

The exothermic industrial byproduct may be mixed with the mixed sludge at a weight ratio of 1: 9, and the mixed sludge dried at the mixed evaporation step (S200) may have about 30% moisture removed.

As described above, in the present invention, the mixed sludge is primarily dried by mixing the industrial byproducts with the byproducts of the industrial by-products treated as waste, so that the mixed sludge is primarily dried, There is an effect of reducing energy consumption. Also, the drying time for removing water from the mixed sludge can be greatly shortened and the drying efficiency is increased.

In the dry evaporation step (S300) of the present invention, the mixed sludge primarily dried in the mixing evaporation step (S200) is heated and dried for a set time at a predetermined temperature. The heating temperature of the drying evaporation step (S300) And is set at a temperature of 100 to 200 ° C. Whereby the mixed sludge is secondarily dried.

The dry evaporation step (S300) is performed for 12 to 24 hours, and the mixed sludge dried in the dry evaporation step (S300) may have a water content of 10% or less. The drying time in the dry evaporation step (S300) may be reduced by about 1.5 to 2 times according to the mixing evaporation step (S200).

The firing dewatering step (S400) of the present invention is for removing organic matter contained in the mixed sludge dried in the drying step. The sludge includes a chemical admixture for concrete, and various kinds of sludge used in the sludge mixing step of the present invention may contain various organic substances. In the present invention, the organic matter or the chemical admixture is finally removed to reduce the strength of the concrete. It is possible to prevent one or more condensation or cracks from occurring.

FIG. 2 is a photograph before and after the firing dewatering step (S400) according to an embodiment of the present invention. 2, a scanning electron microscope (SEM) was used.

FIG. 2 (a) shows a photograph before firing, and FIG. 2 (b) shows a photograph after firing. As shown in FIG. 2 (a), before the calcination dehydration step (S400) of the present invention is performed, a hydration product, ettringite, is seen. The mixed sludge, When aggregates or concrete products are manufactured, cracks (cracks) are generated by causing expansion in the concrete block, so there is a restriction in using simple sludge to dry. In the present invention, the etching ring is removed from the mixed sludge through the firing dewatering step (S400).

As shown in FIG. 2 (b), after the calcination, the ettringite is removed as crystal water is decomposed by the high temperature and exhibits a homogeneous particle shape when compared with that before calcination. Accordingly, in the present invention, quality uniformity can be ensured.

The firing dewatering step (S400) may be performed at a set temperature of 650 to 1000 ° C, and the firing dewatering step (S400) is preferably performed for 12 to 24 hours.

The recycled aggregate formed by sequentially performing the sludge mixing step, the mixed evaporation step (S200), the dry evaporation step (S300) and the plastic dehydration step (S400) of the present invention may be pulverized so that particles are evenly distributed, have.

The recycled aggregate formed through the above-described steps may be used as coarse aggregate, fine aggregate, or separately in the production of concrete or the like, and may be used as a substitute for other materials added when the concrete is manufactured.

Table 1 below shows the blending ratio when the concrete product is manufactured using the recycled aggregate formed according to the forming method of the present invention, and when it is manufactured as a dry product.

Unit quantity cement Fine aggregate Stone Sludge Remarks Comparative Example 1 120 370 200 1900 0 Example 1 120 370 200 900 1000

<Formulation ratio when manufacturing dry products (unit: Kg)>

As shown in Table 1, Comparative Example 1 means a blending ratio used in the production of general concrete, and Example 1 means a blending ratio using recycled aggregate (using sludge) formed according to the present invention.

Table 2 and Table 3 show the compressive strengths of the concrete products manufactured according to the mixing ratios shown in Table 1 according to age.

Comparative Example 1 3 days 7 days a year 14 days 28 days old 56 days a year One 12.9 20.4 21.8 29.4 30.2 2 13.5 19.9 24.5 26.8 31.2 3 14.8 19.7 22.9 28.6 29.4 4 14.2 20.4 22.8 27.2 30.6 5 13.5 20.2 24.0 28.5 30.4 Average 13.8 20.1 23.2 28.1 30.4

&Lt; Compressive strength (unit: MPa) according to age in Comparative Example 1 >

Example 1 3 days 7 days a year 14 days 28 days old 56 days a year One 15.3 25.2 26.9 28.9 32.1 2 14.5 24.2 28.1 30.2 32.4 3 16.2 24.5 27.6 31.1 33.6 4 15.1 23.7 27.2 30.7 31.8 5 15.0 24.8 26.9 29.9 32.9 Average 15.2 24.5 27.3 30.2 32.6

&Lt; Compressive strength (unit: MPa) according to the age of the first embodiment >

As shown in Tables 2 and 3, when the concrete is manufactured using the recycled aggregate according to the present invention, the overall improvement in compressive strength can be expected.

FIG. 3 is a graph comparing compressive strengths of an embodiment in which a recycled aggregate according to an embodiment of the present invention is incorporated and a comparative example.

As shown in FIG. 3, in the case of Experimental Example 1, overall strength is higher than that of Comparative Example 1 from 3 days of age to 56 days of age. This is because the fine particles contained in the mixed sludge fill the pores in the production of the concrete.

Table 4 below shows the blending ratio when the concrete product is manufactured using the recycled aggregate formed according to the forming method of the present invention, and when it is produced as a wet product.

Unit quantity cement Fine aggregate Coarse aggregate Sludge Remarks Comparative Example 2 120 360 500 1050 0 Example 2 120 360 100 900 550

<Formulation ratio when manufacturing wet products (unit: Kg)>

As shown in Table 4, Comparative Example 2 means a blending ratio used in general concrete production, and Example 2 means a blending ratio using recycled aggregate (using sludge) formed according to the present invention.

Tables 5 and 6 show the compressive strengths of concrete products manufactured according to the formulation ratios shown in Table 4 according to age.

Comparative Example 3 days 7 days a year 14 days 28 days old 56 days a year One 14.2 21.2 22.6 28.7 30.5 2 14.5 20.8 24.3 29.3 31.5 3 14.1 20.6 23.4 29.5 31.2 4 13.9 20.4 23.8 29.1 30.7 5 13.5 22.1 24.3 29.8 30.4 Average 14.0 21.0 23.7 29.3 30.9

&Lt; Compressive strength (unit: MPa) according to age in Comparative Example 2 >

Example 3 days 7 days a year 14 days 28 days old 56 days a year One 16.2 23.1 24.9 30.2 36.2 2 15.8 23.5 26.6 31.2 37.4 3 16.1 23.9 26.1 31.8 37.1 4 16.3 24.1 26.4 31.2 36.5 5 15.9 24.2 26.2 32.1 36.1 Average 16.1 23.8 26.0 31.3 36.7

&Lt; Compressive strength (unit: MPa) according to the age of the second embodiment >

As shown in Tables 5 and 6, when the recycled aggregate of the present invention is used, the effect of improving the overall strength of the wet concrete product can be expected.

The recycled aggregate formed through the above steps and the concrete block using the same have the effect of improving the durability and strength, facilitating the recycling of resources, reducing the energy consumption during drying and reducing the manufacturing cost.

S100: Mixed sludge formation step
S200: Mixture evaporation step
S300: dry evaporation step
S400: Firing dehydration step

Claims (8)

A mixed sludge forming step of mixing mixed sludge at a predetermined ratio to form a mixed sludge;
Mixing and evaporating the water contained in the mixed sludge by mixing industrial byproducts having exothermic properties with the mixed sludge;
Drying the mixed sludge in which moisture is evaporated at 100 to 200 ° C; And
And a calcination dehydrating step of calcining the mixed sludge dried in the drying and evaporating step at 650 to 1000 ° C,
In the mixed sludge forming step,
Wherein the sludge comprises 40 to 60 wt% of centrifugal force concrete sludge, 15 to 25 wt% of remicon sludge, 15 to 25 wt% of stone sludge, and 5 to 15 wt% of sewage sludge. / RTI &gt;
delete delete The method according to claim 1,
In the mixed vaporization step,
Wherein the exothermic industrial byproduct comprises at least one of paper ash, coke oven ash, desulfurization gypsum, and burnt lime.
5. The method of claim 4,
Wherein the mixed vaporization step comprises:
Wherein the exothermic industrial by-products and the mixed sludge are mixed at a weight ratio of 1: 9.
The method according to claim 1,
The drying step comprises:
Wherein the mixed sludge is dried for 12 to 24 hours, and the mixed sludge dried in the drying step has a water content of 10% or less.
The method according to claim 1,
The firing dewatering step comprises:
The method according to claim 1, wherein the sludge is treated for 12 to 24 hours.
A concrete block formed by using the recycled aggregate produced by the method of forming the recycled aggregate according to claim 1.

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