CN1353019A

CN1353019A - Production equipment of regenerated aggregate using building waste material as raw material and regenerated aggregate

Info

Publication number: CN1353019A
Application number: CN00133481A
Authority: CN
Inventors: 吴钟泽
Original assignee: IN-SON ENTERPRISE Co Ltd
Current assignee: IN-SON ENTERPRISE Co Ltd
Priority date: 2000-11-08
Filing date: 2000-11-08
Publication date: 2002-06-12

Abstract

An apparatus for regenerating aggregate with the waste building materials is composed of multi-stage crusher for crushing the said waste materials, several conveying belts for conveying the crushed materials to designated positions, separators for separating aggregate from the waste material, blower, water tank for washing the aggregate, forcing delivering unit for delivering the floated substance, and water recovering and settling tank. The regenerated aggregate is coated by water glass to fill voids of its surface lowering absorbance and raising surface strength.

Description

Recycled aggregate production device taking building waste as raw material and recycled aggregate

The present invention relates to an improved production apparatus for producing recycled aggregate having low absorption rate and high quality by efficiently treating building waste, thereby effectively solving the problems of insufficient resources and environmental protection, and a recycled aggregate produced thereby, and more particularly, to an apparatus for producing recycled aggregate using building waste as a raw material, and a recycled aggregate.

So-called development priority and high-speed growth policy are being pursued, and the side effect thereof is that environmental problems are often involved.

In particular, the construction industry waste of various building and civil engineering works tends to increase abnormally and rapidly. The main reasons for this phenomenon are: since buildings in large cities and places are aged and degraded and functions are reduced, re-development, reconstruction and reconstruction, and demolition of buildings are actively performed, sometimes due to natural disasters such as earthquakes.

The construction waste generally refers to soil, sand, pebbles, earth and stones mixed together with garbage, waste materials, etc., soil sand, concrete blocks, waste wood, asphalt concrete blocks, construction sludge, etc., or a mixture thereof. Most of it is made of inorganic substances and is harmless to human body.

However, since a plurality of wastes are discharged in a mixed state, the disposal process is complicated and difficult, which is an inherent characteristic of building wastes, it has not been possible to dispose of them well and to make them fully use as useful materials.

Therefore, on the one hand, this is a waste of valuable resources, and on the other hand, some recycled aggregates produced restrictively by using a part of the recycled aggregates are poor in quality and cannot be reused as building aggregates, and in fact, most of the recycled aggregates are used for replacing earth and sand for agricultural cultivation, covering, landfill and the like.

For this reason, it is necessary to process and manage such waste materials so that they can be substantially reused, thereby reducing environmental pollution, replacing scarce resources, and actively striving to reduce the overall cost of the construction industry.

In response to such a demand, some production facilities for recycling waste materials have been manufactured and used on the construction site. A typical example of this is the crusher (crusher) currently being used by various construction enterprises.

Accordingly, in each construction site, there is an active strive to reuse waste materials despite the restrictions on the conditions. As described above, construction waste is discharged in many mixed states in most cases, and it is difficult to sufficiently ensure the performance and quality of a mobile machine as a crusher.

As the existing techniques related to the production apparatus of the present invention, the following technical solutions have been proposed.

First, Korean Utility model publication No. 94-4771 discloses an apparatus related to a "garbage disposer". The apparatus is configured to collect more reusable resources by cutting and sorting metallic and non-metallic substances, separating soil and dust, and the like while the garbage falls freely by its own weight.

For this purpose, a 1 st roller crusher comprising a refuse inlet, a 1 st conveyor belt, and a roller to which a lug is attached is provided on an upper portion of an inclined frame, and the following are provided in this order: the device comprises a 1 st magnet conveyor belt composed of an electromagnet roller, a non-magnetic roller and a circular tube, a cutting machine composed of a supporting blade and a movable blade, a 1 st filter screen, a 2 nd roller crusher, a 2 nd conveyor belt, a 2 nd filter screen and a 3 rd horizontal conveyor belt.

Further, Japanese patent publication No. 6-30755 discloses a method and apparatus for crushing, classifying and recycling concrete fragments as decomposed concrete fragments of buildings, civil engineering structures, secondary concrete products and the like, which is constituted by: the collected waste material is thrown into a rotary drum which is formed with a plurality of projections on the inner surface and eccentrically rotates by a power generating device, the crushed waste material falls downward by the weight of the crushed waste material, the powder is thrown into other processes again through a conveying channel on the upper side, and then the powder is discharged, and the fine powder can be separated through a retreatment process.

However, the above-cited inventions and inventions do not sufficiently achieve the object of automatically separating construction waste materials in which various waste materials are mixed together and producing high-quality recycled aggregate from the construction waste materials, and their effectiveness is very low, and therefore, many improvements are required to be made to reliably apply the present invention to various industrial fields.

In a construction waste reclamation system including sewage channel dredging soil, a process of crushing, sorting, and washing, which is a typical waste disposal method, is installed on a continuous flow line, and useful materials are reclaimed from the input waste. Although for this purpose, in the case of using such a system, as a whole, in a state where various wastes are mixed together, since the constituent devices are not properly arranged, it is difficult to automatically and precisely sort the aggregates, the durability of the screen and the conveyor belt is impaired, frequent breakage is caused, the degree of pollution during washing is serious, and the used water is difficult to reuse.

That is, the sorting machine constituted by the rotary drum has a problem that scraps of hexene, fiber pieces, synthetic resin, etc. are stuck on each screen to lower the working efficiency thereof, and the scraps must be removed by a separate heating torch. In the "air separation" system in which an air blower is installed at a drop point of a conveyor belt, the efficiency of garbage separation is inevitably lowered due to the curtain falling phenomenon between aggregates because of the use of air force while aggregates are directly dropped onto a narrow conveyor belt in a state where the aggregates are stored thick.

Therefore, in order to solve these problems, a sorting method has been adopted in which a large number of workers are arranged around the aggregate conveying belt and the garbage is sorted by individual manual works. Meanwhile, the conveyor belt utilizing system for water passing is combined with the conveyor belt which uses the water storage tank to simply convey the aggregate for use. Further, the 1 st crushing → sorting, washing, and vertical discharging method for processing construction waste may be adopted. The main objects of sorting are only the sawdust, waste paper, and plastics mixed into construction waste, and the waste synthetic resin and foamed resin including ethylene, etc., and the recycled aggregate is partially produced, and the production process thereof naturally requires excessive time and effort, and it is difficult to expect the product quality to a high level in reality.

In particular, in the recycled aggregate production system using waste concrete blocks, which account for most of construction waste, the waste concrete blocks are crushed into appropriate sizes in advance according to the use and capacity of a crusher before being fed into a recycling facility, and then fed into the recycling facility, the fed waste concrete blocks are crushed by a Jaw crusher (Jaw crusher) (capacity 100 tons/hour) to remove unnecessary materials, and then crushed by an impact crusher (capacity 100 tons/hour), and finally remaining reinforcing bar pieces are removed by a magnetic separator, and sorted by using different grades of meshscreens, so that recycled aggregates of desired sizes can be sorted.

However, even with this process, the fine aggregate is coarse and difficult to use alone, the properties of the aggregate vary with the particle size, the smaller the particles, the smaller the specific gravity and the higher the absorption rate, and the recycled aggregate processed by the above process is reduced in quality by the small particles and the large amount of cement paste components.

For example, the absorptivity determining the general mass of the aggregate is about 7 to 13%, and therefore, the use thereof as a high-quality aggregate is hindered. Recycled aggregate obtained by crushing waste concrete blocks has a phenomenon that the absorption rate of the aggregate itself is improved due to mortar and various impurities adhering to the surface of the aggregate, and when the recycled aggregate is put into concrete or concrete products, the adhesion of mortar to the surface of the aggregate is reduced, and the crushing strength is also reduced.

Therefore, the object of the invention is: it is needless to say that in the conventional process divided into crushing, sorting and washing, a garbage blowing method is added to a flat screen blanking site, a method of washing recycled aggregates with water and an automatic garbage sorting method are used, and a forced return method for improving the particle shape of the recycled aggregates is applied to produce useful materials.

In order to achieve the above object, the present invention provides an apparatus for producing recycled aggregate using building waste as a raw material, comprising:

1 st crushing device for crushing the collected construction waste into a size of 200mm or less in a state where various wastes are mixed together;

1 st conveyor means for loading and conveying said crushed scrap and having a magnetic separator capable of removing metallic materials mixed into the scrap;

1 st sorting means for sorting the transported waste into earth and sand and aggregate of 40mm size, and for this purpose, filtering the waste while vibrating;

a blower which forms a vortex phenomenon of air pressure at the lower end of the sorting device 1 in order to easily sort and discharge the waste aggregates;

a water tank for washing the sorted aggregates and separating suspended matter by an underwater aeration tank including a high-pressure water nozzle;

a suspended matter forced pressure feeding device for separating the suspended matter in a state of being forced to be pressure-fed together with water;

a water recovery and precipitation tank for adding a coagulant and performing a water replenishment treatment to purify the separated water;

a 2 nd conveyor means disposed in the water tank so as to continuously draw out the washed aggregates, wherein a water recovery screen is provided for separating the aggregates from the water;

a 2 nd crushing device for crushing the extracted aggregate into at least 45 to 75mm when the extracted aggregate is charged;

a 3 rd conveyor belt device for separating the residual metal materials by a magnetic separator while conveying the crushed aggregates;

a 2 nd separating device for separating and discharging the aggregate separated from the metal material into at least 25mm or less sizes;

a 4 th conveyor means connected to the 2 nd sorting means and arranged to have a magnetic separator for re-conveying aggregates of a specific size of 25mm or more;and

and a 3 rd crushing device for crushing the conveyed aggregates again below a predetermined size and then loading the aggregates onto the 2 nd conveyor device.

The recycled aggregate is characterized in that: the aggregate discharged through the above treatment process is coated with a water glass, i.e., a permeable inorganic substance reaction type modifier water glass having a pH of 10.5 to 11.5, a solid content of 30 to 70% and a specific gravity of 2.4, so that calcium silicate and colloidal silicic acid are generated in voids on the surface of the aggregate in the presence of ammonia ions and halogen ions due to the coating penetration of the alkali silicate aqueous solution, thereby forming a filled high-quality recycled aggregate.

The apparatus for producing recycled aggregate and the recycled aggregate according to the present invention will be described in further detail with reference to the drawings showing examples, wherein the same reference numerals denote the same elements throughout the drawings.

FIG. 1 is a configuration diagram showing an overall installation state of a production apparatus of the present invention;

FIG. 2 is an enlarged plan view showing a production apparatus of the present invention, and is a configuration diagram showing a transport route and a position and arrangement of equipment for disposing wastes;

FIG. 3 is a view showing an example of a state in which the aggregate to be recycled according to the present invention is impregnated with an aqueous solution of a water glass component and covered with the aqueous solution.

Referring to fig. 1 and 2, the overallarrangement of the production apparatus according to the present invention is shown. The work of the present invention is a process of charging the first construction waste, and includes, of course, a process of finally separating and discharging aggregate of, for example, 25mm to 9mm or aggregate of 9mm or less, and also includes many possible disposal methods for standby which may occur in the work.

The standby after-treatment method may be a method of treating the earth sand by separating the aggregate and the earth sand when the waste is sorted, or another method of treating the floating matter such as the waste wood mixed with the aggregate when the floating matter occurs in the process of cleaning the aggregate.

The device of the invention has a complete equipment arrangement design as shown in the attached drawing, and the whole device works in a full-automatic system mode in a central centralized control mode, so that the reduction of required personnel and the expansion of the workload can be realized in a short time.

The collected waste material is fed directly to the 1 st crushing unit without further sorting, and the 1 st crushing unit is preferably constituted by a jaw crusher 1.

The size of the crushed aggregate may be arbitrarily selected, and the crushed aggregate is generally required to be crushed to a size of about 200mm or less, but is not limited thereto.

The aggregates after the first crushing by the jaw crusher 1 are separated by a magnetic separator 2a which is an iron sheet separator located right below the jaw crusher to separate various metal substances, and the crushed aggregates are continuously dropped onto a conveyor belt 2 which is a conveyor belt 1 to be conveyed. At this time, the magnetic separator 2a is fixed to one side upper end of the conveyor belt 2, and its setting requirements are: aurethane (polyurethane) plate is fixed to an upper portion of a support portion of the conveyor belt in order to absorb various metal pieces including reinforcing bar chips, nails, etc., while maintaining a gaussian having a sufficient strength, and to prevent the durability of the conveyor belt 2 from being lowered due to the falling of waste, in order to absorb vibration and pressure generated by the falling of waste.

The conveyor 2 is set to be capable of gradually rising to the upper side based on the waste falling place; the 1 st sorting device in an inclined form is fixed in a state of being inclined downward from just below the front end of the conveyor belt 2.

The 1 st sorting device is a plane vibration type screen 3 which is repeatedly vibrated at a certain period by an external power, and is installed for separating earth and sand from aggregates, and it is preferable that a punching iron plate 3a is used instead of an iron net to prevent ethylene, fiber chips, filament pieces, etc. from being caught by the net. Thus, the replacement cycle can be extended to remarkably improve the durability. In order to utilize the advantage of the circular screen, that is, the effect of preventing the waste from scattering to the outside, it is natural to provide guide side walls on both sides, and screening is generally performed to separate and sort out aggregates having a size of 40 mm.

A plurality of large blowers 3b and 3c are provided as air blowing devices on both sides of the lower end of the punching iron plate 3a so that the aggregates are thrown into a horizontally disposed water tank 4 made of hard rubber material, and the water tank 4 is located below the obliquely disposed plane vibration type screen 3.

Here, since the rectangular air outlet is provided at the lower end of the blanking place of the punching iron plate 3a, the size of the air outlet is increased by about 4 to 5 times as compared with the conventional conveyor belt system, the plurality of air blowers 3b and 3c are alternately provided to generate a vortex flow of air in order to maintain the wind strength of the air outlet at a uniform level when the wind strength of the air outlet is not constant, and the vortex flow thus formed can be extended to the ejection place along the air outlet line, thereby facilitating the discharge of the aggregate.

After the aggregates sorted through this process are put into the tank, the water tank 4 required for the cleaning process and the garbage sorting process, which includes the nozzle 4a for cleaning the inside, the nozzle 4b for cleaning the aggregates, and the underwater explosion tank 4c, is formed to have a tapered shape so that the position where the aggregates fall down is deep and the water tank can be maintained to be gradually lowered toward the other side.

The nozzle 4a for cleaning the water tank is arranged at a nozzle arrangement angle selected so as to be capable of spraying from a lower part to a deeper part for automatically cleaning the sludge in the water tank 4, and a plurality of nozzles 4b for high-pressure cleaning are provided at the upper end of the water tank 4 together with a water spray device (about 5 sets) for forming a water flow, and a large amount of water is sprayed with high pressure to form a strong water flow, thereby cleaning the aggregates, and floating garbage is caused to flow to the water recovery channel side behind the water tank 4 by the underwater aeration tank 4 c.

On the other hand, the underwater aeration tank 4c is mainly provided outside the water tank 4, and the compressed air generated therein is pressure-fed to the underwater lower end of the water tank 4 through a pipe. The compressed air pumped into the water floats to the water surface while generating countless bubbles, and functions to wash the recycled aggregate charged into the water tank 4 and increase the floating force in the water tank 4 to float various garbage mixed in the aggregate to the water surface.

In this case, the diameter of the aeration nozzle for discharging compressed air formed in the pipe of the underwater aeration tank 4c provided at the underwater lower end of the water tank 4 is preferably about 3 mm.

In the water recovery passage behind the water tank 4, a garbage separation and rotation unit 5 or a driven screw is provided as a floating matter forced pumping unit, and water is overflowed to the outside of the water tank by a rotational force of high vibration, so that floating matters such as waste wood and waste synthetic resin can be forcibly discharged to the outside.

The floating garbage collected by the water flow in the water tank 4 is forcibly discharged together with water by the garbage separating and rotating unit 5, and at the same time, falls onto the separation screen 3 made of the punching iron plate 3a provided at the lower end thereof to separate the floating garbage and water from each other, and the garbage is sent to another warehouse 6 by the conveyor 2, temporarily stored and discharged, and the waste water flows into the water recovery and sedimentation tank 7.

The water recovery and sedimentation tank 7 is mainly fabricated on the lower part of the floor by a concrete construction method, and is divided into about 4

continuous sedimentation tanks

7a, 7b, 7c, 7d, and water is passed through them in sequence, and a transfer passage between the tank walls is formed on the lower side.

In addition, in the

respective settling tanks

7a, 7b, 7c, and 7d, the settled soil formed by settling by its own weight is subjected to a suitable discharge scheme in order to be treated according to the relevant regulations, and the soil contains a large amount of organic components, so that the soil is widely recycled.

On the other hand, purification of the water flowing into the water recovery and precipitation tank 7 is completely feasible by adding a polymer flocculant and continuously circulating water replenishment treatment. The coagulant used in this case is aluminium sulphate [ Al]which is generally used₂(SO₄)₃]And ferrous sulfate [ Fe]₂(SO₄)₄]The water purified by stages can be reused (this is because the construction waste is composed of inorganic substances and the nature of the water used is relatively simple).

In the water tank 4 having a cone-like structure, a water tank conveyor 2 as a 2 nd conveyor means is provided in the water tank 4 so that the cleaned aggregates are discharged to the outside while sequentially rising, and it is preferable to reduce the conveying speed as much as possible in order to stabilize the recycled aggregates, and a water recovery screen 3 is provided at the upper end thereof so as to separate the cleaning water fed together with the aggregates. This is to prevent water from entering the next process to cause malfunction of the machine, and it has a vibration generating function like other nets.

Then, the aggregates separated from the water continuously fall down and are thrown into a jaw crusher 1 provided as a 2 nd crushing device, and crushed into aggregates having a size of at least 45 to 78mm, and the crushed aggregates are conveyed by a conveyor 2 which is a 3 rd trough conveyor obliquely provided on the upper side in the same arrangement as the 1 st conveyor, and are dropped and thrown into a planar vibrating screen 3 which is a 2 nd sorting device maintaining the same arrangement as the 1 st sorting device. A freely movable magnetic separator 2a is also provided above the conveyor belt 2, so that the residual metal pieces not completely removed in the 1 st separation process can be removed.

Further, a plurality of air blowers 3b and 3c are provided at both lower ends of the perforated iron plate 3a of the plane vibration type screen 3 to form a vortex of air.

The aggregates separated from the metal material by the screen 3 are separated into at least 25mm or less, and finally separated into 25mm to 9mm aggregates and 9mm or less aggregates, and discharged. For this purpose, it is needless to say that a separate conveyor belt, a separate magnetic separator, and the like are provided, and the diameter (mesh size) of the punching iron plate 3a may be adjusted in consideration of the production conditions and supply and demand conditions of the recycled aggregate.

At this time, the aggregate of 25mm or more after the screening is forcibly conveyed by the blowers 3b and 3c for re-crushing. Therefore, the 4 th belt conveyor device to which the iron piece separating magnetic separator 2a is attached, that is, the conveyor 2 is installed to be inclined upward with reference to the falling point of the conveyed aggregate, and the conveyed aggregate is thrown into the cone crusher (cone crusher)8, which is the 3 rd crushing device directly below the conveyor, and then crushed by the rotating force and the frictional force of the crusher, so that the particle shape of the aggregate can be improved and the wear resistance can be improved.

However, since the magnetic separator 2a is provided in the 4 th conveyor belt device to remove the wire, nail, iron core, etc. of the fine pieces contained in the concrete, and thus the quality and commercial value of the recycled aggregate can be improved, since the mechanical device is seriously damaged if the small iron pieces flow into the cone crusher 8.

The aggregates after the re-crushing are fed againinto the 3 rd conveyor through the lower part of the cone crusher 8, and then circulated in the above-described process, and if necessary, may be directly fed into the warehouse 6 without a conveying process.

The above-described cone crusher 8 can also be replaced by an impact crusher to achieve the same object. However, since the impact crusher has a high wear rate of mechanical parts, a high maintenance cost, a long time, and a low equipment operating rate, it is preferable to use the cone crusher 8.

On the other hand, the power generation device of the present invention is operated by an electric motor, but a hydraulic drive motor may be used in each device in which another engine is mounted. It is optional to attach a pallet or crawler as appropriate, which can facilitate the positional movement of the respective process machines.

Referring to FIG. 3, there is shown an example of the state of the water glass component in the form of an aqueous solution impregnated and coated when the aggregate regenerated by the above-mentioned apparatus is used in concrete. The recycled aggregate produced by this process is then coated with a sufficient amount of water glass on its outer surface. Thus, the recycled aggregate produced is impregnated with water glass of a permeable inorganic substance reaction type modifier having a pH of 10.5 to 11.5, a solid content of 30 to 70% and a specific gravity of 2.4 to absorb a certain amount of water, or the water glass is sprayed with water in a dry state of the aggregate to impregnate the surface voids of the recycled aggregate with an aqueous alkali silicate solution, calcium silicate and colloidal silicic acid are produced in the presence of halogen ions and filled in the voids, and the recycled aggregate is covered to reduce the absorptivity thereof, thereby improving the strength as a concrete aggregate and improving the quality of the aggregate.

The invention has been illustrated above with reference to specific preferred embodiments. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the claims that follow.

As described above, in the case of producing a recycled aggregate of good quality from construction waste, the present invention can continuously and stably produce the recycled aggregate at a low production cost, and therefore, can suppress the occurrence of environmental pollution and effectively utilize resources. For example, when the construction waste is produced by dividing into-6 mm reclaimed sand, 9mm reclaimed sand, 25mm reclaimed aggregate, and soil sand, the ratio of the amount of the construction waste to the amount of the aggregate produced is shown in Table 1 below.

TABLE 1 ratio of construction waste input to aggregate production

As described above, the result of the operation of the recycled aggregate production facility is the statistical value of the recycled aggregate production ratio shown in Table 1, and the construction waste of the present invention has a treatment capacity of 200 m/hr based on the statistical value³The 1-day yields of the respective aggregates were calculated by multiplying the working time of 1 day and 8 hours, and the results are shown in Table 2 below.

TABLE 2 production in one day

As shown in Table 2, the production amount of the aggregate having a thickness of about 25mm was 560m in 1 day³320m of-9 mm sand³240m of sand with the thickness of-6 mm³The separated sand amountis 480m³。

Wherein the low-grade sand is supplied for agricultural cultivation, covering soil and burying in building and civil engineering, and aggregate is not finely classified, the total amount of aggregate produced in 1 day is 1120m³。

Therefore, the produced aggregate is utilized in the construction industry, and has a wide application range: aggregate with the thickness of 25mm can be mainly used as road auxiliary base material, concrete wall filling material and the like; the sand of about 9mm can be used for concrete products such as tiles, boundary stones and the like; the-6 mm sand can be used as a pipeline construction landfill material for manufacturing concrete products.

In particular, the durability and water-repellency of the aggregate can be improved by impregnating a colorless and odorless aqueous solution of alkali silicate into the porous aggregate to completely fill the voids Can proceed to form ions and SiO in the concrete₃The combined silicate reacts with colloidal silicic acid filled in the gaps, so that glassy insoluble crystals are formed on the inner and outer surfaces of the aggregate, and an aqueous solution which reacts with Ca, Mg and Al ions to increase the crystallization force is used in the concrete, so that the absorption rate of the recycled aggregate can be reduced, cracks can be reinforced, the binding force with new mortar can be increased, the absorption rate of the aggregate can be reduced, and the quality of the concrete can be improved.

Claims

1. A production device of recycled aggregate using building waste as raw material is characterized by comprising:

1, crushing the collected construction waste into the size of less than 200 mm;

1 st conveyor means for loading and conveying the crushed scrap and having a magnetic separator capable of removing the metal materials mixed in the scrap;

a blower unit located at the lower end of the 1 st separator, which forms a vortex phenomenon of air pressure for easily separating and discharging the waste aggregates;

a water tank which is an underwater aeration tank including a high-pressure water nozzle and is used for cleaning the sorted aggregate and separating out suspended matters;

a suspended matter forced pressure feeding device for separating suspended matter in a state where the suspended matter is forcibly conveyed together with water;

a water recovery and precipitation tank for purifying the separated water, and for this purpose, adding a coagulant and performing water replenishment treatment;

a 2 nd conveyor belt device disposed in the water tank so as to continuously take out the washed aggregates, wherein a water recovery screen for separating the aggregates from water is attached;

a 2 nd crushing device for crushing the drawn aggregate into at least 45 to 75mm when the drawn aggregate is thrown in;

a 3 rd conveyor belt device for separating the residual metal material by a magnetic separator while conveying the crushed aggregate;

a 2 nd separating device for separating the aggregate separated from the metal material into at least 25mm or less, and then separating and discharging the aggregate according to the size;

a 4 th conveyer belt device which is connected with the 2 nd sorting device for setting and is provided with a magnetic separator for retransmitting the aggregate with specific size of more than 25 mm; and

and the 3 rd crushing device is used for crushing the conveyed aggregates into the aggregates with the size below a specified size and then loading the aggregates onto the 2 nd conveyor belt.

2. A recycled aggregate characterized by: a method for producing an aggregate which comprises applying a permeable inorganic substance reaction modifier water glass having a pH of 10.5 to 11.5, a solid content of 30 to 70% and a specific gravity of 2.4 to a recycled aggregate, and filling voids in the surface of the aggregate with calcium silicate and colloidal silicic acid formed by the application and permeation of an alkali silicate aqueous solution in the presence of ammonia ions and halogen ions, whereby the absorption rate of the aggregate can be reduced and the strength and binding force can be improved.