JP2006016217A - General waste incineration ash regenerated aggregate and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, regarding the conventional regenerating method for general waste incineration ash, the application of regenerated products has been limited to specified purposes such as civil engineering materials, and the consumption demand in an amount corresponding to that of the regenerated products has not been expected, thus the surplus products must be carried into final disposal places after all. <P>SOLUTION: General waste incineration ash is sorted and classified by prescribed grain size by a grain size sorting screen 18, and is coated with cement and lime fine powder using a formalin condensate admixture of melamine sulfonate, so as to be formed into concrete aggregate for a secondary product to which a lot of consumption demand is expected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a general waste incinerated ash recycled aggregate obtained by regenerating general waste incinerated ash into an aggregate of civil engineering materials or concrete for secondary products, and a method for producing the same.

  Currently, about 50 million tons of general waste is generated annually in Japan, and about 40 million tons are incinerated, resulting in about 6 million tons of incineration ash. About 100,000 tons have been converted to the final disposal site.

  Conventionally, as a method for regenerating general waste incineration ash, blast furnace granulated fine powder containing gypsum is added to and mixed with general waste incineration ash together with water, and the mixture is used as an extrusion molding machine. A method for forming the mold (for example, see Patent Document 1) has been developed.

Further, a method has been proposed in which lead contained in general waste incineration ash is contained in general waste incineration ash by desulfurization sludge or a mixture of desulfurization sludge and coal ash (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 9-174019 JP-A-10-277516

  However, the method of adding and mixing blast furnace granulated fine powder containing gypsum with incinerated ash to general waste incinerated ash and extruding the mixture can be expected to completely block the elution of heavy metals in the incinerated ash. However, since the blast furnace granulated fine powder itself contains harmful substances, there is a problem that it is necessary to construct a large-scale processing plant by adopting a means for extrusion of the mixture in order to prevent elution.

  In addition, the method of containing lead contained in municipal waste incineration ash with desulfurization sludge or a mixture of desulfurization sludge and coal ash requires that the desulfurization sludge itself is an industrial waste and requires special treatment, and the heavy metals sealed are also limited to lead. There is a problem.

  A further problem with these conventional waste incineration ash recycling methods is that the use of recycled products is limited to specific purposes, such as civil engineering materials, and demand for consumption corresponding to the amount of recycled products is expected. As a result, surplus products are eventually brought to the final disposal site.

  Furthermore, the conventional treatment method requires a very high cost for the construction of the treatment plant, so it cannot be profitable unless a large amount of municipal waste incineration ash is processed in proportion to this, and the generation of incineration ash is local. In order to collect a large amount of municipal waste incineration ash that can be profitable because it is dispersed, it is necessary to move the incineration ash over a long distance, and the opposition of residents due to high costs due to transportation costs and pollution along the movement It becomes a problem.

  In order to solve the above-mentioned problems, the present invention sorts municipal waste incineration ash according to particle size, and uses an admixture mainly composed of a formalin condensate of melamine sulfonate and cement. By coating with limestone fine powder, heavy metal elution was sealed off and used as recycled aggregate.

  In other words, the formalin condensate of melamine sulfonate facilitates the familiarization of the general waste incineration ash with a fixed particle size with the cement and limestone fine powder used as the coating material, thereby separating the coating material from the incinerated ash aggregate. This is used to block heavy metal elution.

  In addition, as a coating method, a formalin condensate of melamine sulfonate is formed into an aqueous solution mixed with water and sprayed onto waste incinerated ash that is sorted according to a certain particle size to humidify the coating environment. The blending design was adjusted so that the adjustment and the moisture content of the measured waste incineration ash were adjusted, and appropriate mixing could be performed by mechanical mixing with cement and fine limestone powder by a mixer.

  Furthermore, the particle size of general waste incineration ash is classified into 5 mm or less, more than 5 mm and less than 10 mm, more than 10 mm and less than 15 mm, and concentrated instead of dispersed construction sites. Generated into concrete aggregates for secondary products as materials in factory processing where a large amount of consumer demand is expected, and processed recycled products are supplied to the demand site at once to suppress the generation of surplus recycled products. The use was promoted.

  In this way, by reusing treated recycled products as raw materials for factory processed products, rational use of treated recycled products is promoted through cooperation between the municipal waste incineration ash treatment plant and the concrete secondary product plant. is there.

  Embodiments of the present invention will be described below with reference to the drawings and the flow of processing. Reference numeral 1 denotes a receiving hopper, which receives the general waste incinerated ash raw material from the collection truck A through an inclined grizzly ring 11 with a vibrator, and supplies it onto a draw-out belt conveyor 2 provided with a magnetic separator 12 for removing foreign matter. The processing amount is about 300 liters (187.5 kg) per batch, and the flow is processed by a motor pulley low speed belt conveyor.

  The magnetic separator 12 is a suspension type automatic discharge type, and it sorts out foreign substances such as ceramics, glass fragments, iron scraps and nails mixed in the incinerated ash raw material conveyed by the lower drawer belt conveyor 2 by magnetic separation. Are automatically discharged and supplied to the particle size sorting screen 13 as pure incineration ash.

  The particle size selection screen 13 is set in three layers: a screen that transmits a raw material with a particle size of 15 mm or less, a screen that transmits a raw material with a particle size of 10 mm or less, and a screen that transmits a raw material with a particle size of 5 mm or less. Separated into diameters of 5 mm or less, 5 mm or more and 10 mm or less, 10 mm or more and 15 mm or less, or 15 mm or more, and remaining on each screen, transported to storage tank The belts 21, 22, 23 are transported to three separate storage tanks 15, 16, 17 for each particle size, and those of 15 mm or more are transported to the oversize yard 14.

  The separated raw materials conveyed and stored in the three separate storage tanks are sequentially fed into the coating mixer 18 for each divided particle size through the measuring belts 24, 25, 26 set in the lower part thereof. A metering load cell 19 is attached to the base portion of the mixer 18 to measure the fractionated raw material that has been input, and an individual blending design corresponding to the amount of fractional raw material input is performed.

  As a basic blending design, 28 kg of water, 2 kg of admixture, 5 kg of Portland cement, and 1 kg of fine limestone powder are designed and calculated according to the particle size and coating environment for 300 kg of general waste incineration ash.

  The fractionated raw material charged in the coating mixer 18 is sprayed with an aqueous mixture of melamine sulfonate formalin condensate as an admixture and water and is humidified. This aqueous solution is mixed with the admixture tank 3 and fresh water. A mixed aqueous solution is prepared in the mixing tank 32 by the admixture and water supplied from the tank 31 to the mixing tank 32 while being metered by the metering pumps P1 and P2 attached thereto.

  The prepared mixed aqueous solution is sent to the pressurizing tank 33, pressurized, sprayed onto the separation raw material rotating in the coating mixer 18 through the fan spray nozzle 34, and humidifies the separation raw material under humidification conditions suitable for the coating environment. .

  Spray humidification is performed by injecting an aqueous solution in which about 2 kg of admixture is added to 28 kg of water with a discharge amount of 8.17 liters per minute and a discharge pressure of 2 kg / square centimeter.

  At the stage where the humidification of the separated raw materials is finished, the cement and limestone fine powder, which are coating materials, are measured from the cement tank 4 and the limestone fine powder tank 41 by the respective measuring tanks 42 and 43, corresponding to the blending design. The raw material is coated on the fractionated raw material by mixing by turning the mixer.

  When coating is completed, the coated fractionated raw material is carried into a quantitative feed hopper 44 equipped with a belt feeder with an inverter, dried through a dryer 45, and then transported to a fractionation storage tank 47, 48, 49 by a hot belt conveyor 46. And stored for each segment particle size.

  In the dryer 45, the burner 5 set on the inlet side blows hot air into the dryer by supplying fuel from the heavy oil tank 51, and the dust and hot air are sucked by the blower 53 through the dust collector 52 and pass through the dryer. The coating separation raw material is dried with hot air. The heating temperature in the dryer is about 50 to 75 degrees C.

  The above steps are sequentially performed for each classified particle size sorting raw material, or are performed by a method in which three sets of processing paths after the classified particle size classification are set and are simultaneously advanced by the set for each classified particle size.

  Recycled aggregates produced by such processing are those having a particle size of 5 mm or less as substitute aggregates for sand, those having a size larger than 5 mm but not larger than 10 mm, those having a particle size larger than 10 mm and not larger than 15 mm, It can be used as a concrete aggregate for secondary products as an alternative aggregate for gravel or crushed stone.

  General waste incineration ash is a raw material with an apparent specific gravity of 1 and a water content of about 20%. The results of a screening test on general waste incineration ash generated at a general waste incineration facility in Takefu City, Fukui Prefecture show the particle size distribution. The particle size is 71.60% for particles of 5 mm or less, 16.30% for particles greater than 5 mm and 10 mm or less, 6.30% for particles greater than 10 mm and 15 mm or less, and 5 for particles larger than 15 mm. 80%. Even if the particles having a particle diameter of 15 mm or more are discarded, the regeneration rate is considerably high.

  As a result of the chloride measurement by the cantab measuring instrument (manufactured by Onoda Cement), the applicant determined that the average value of the chlorine concentration was 0 for the concrete secondary product molded using the recycled aggregate processed and processed as described above. .0061%, the unit water amount was 199 kg / cubic meter, the chlorinated substance was 0.1299 kg / cubic meter, and the result within the standard could be obtained.

  The flow value of the recycled aggregate before processing the secondary concrete product is 590 mm at the maximum and 585 mm at the minimum, the air amount is 2.3%, and the chloride ion amount is 0.129 kg / cubic meter.

  In addition, the strength test results of secondary concrete products molded using recycled aggregates should yield an average of 25.1 newtons / square millimeter 2 days after molding and an average of 36.8 newtons / square millimeter after 7 days. I was able to.

  Further, in tests conducted on weight and volume, the average weight was 3558.0 g and the volume was 1549.8 cubic centimeters two days after molding, and the average weight was 3514.1 g and the volume was average 1550.9 g seven days after molding. It was cubic centimeter.

  Since the present invention is configured as described above, a formalin condensate of melamine sulfonate that facilitates the familiarization of general waste incinerated ash with cement and fine limestone powder and prevents separation from the incinerated ash aggregate is provided. By spraying the waste incineration ash as an aqueous solution and coating it in an appropriate humidified state, the general waste incineration ash can be produced as a stable recycled aggregate.

  In addition, by generating municipal waste incineration ash with a high consumption demand rate into recycled aggregates of concrete secondary products, the concrete secondary product molding plant is equipped with a general waste incineration ash treatment plant to provide the necessary bones for molding. The material can be produced while incineration ash processing is performed, and waste due to excessive regeneration can be eliminated, and the balance between the regenerated output by the general waste incineration ash process and the consumption demand for the regenerated output can be achieved.

The processing apparatus by the Example of this invention is shown, The whole side view of the apparatus which shows the flow system until it removes a foreign material from a general waste incineration ash raw material, performs a particle size division, and is sorted and stored in a division tank Similarly, an overall side view of the apparatus showing the generation of the humidified aqueous mixture and the spray supply flow system to the coating mixer Similarly, the entire side view of the equipment showing the processing raw material supply to the coating mixer and the transport flow system from the coating process to the dryer Similarly, an overall side view of the apparatus showing a drying treatment system with a dryer and a flow system for transporting the output recycled aggregate to the particle size division tank

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Receipt hopper 11 Inclined grizzle with vibrator 12 Magnetic separator which removes foreign substances 13 Grain size selection screen 14 Oversize yard 15 Sort storage tank 16 Sort storage tank 17 Sort storage tank 18 Coating mixer 19 Weighing load cell 2 Drawer belt conveyor 21 Conveying belt to storage tank 22 Conveying belt to storage tank 23 Conveying belt to storage tank 24 Measuring belt 25 Measuring belt 26 Measuring belt 3 Admixture tank 31 Fresh water tank 32 Mixing tank 33 Pressurizing tank 34 Fan-shaped spray nozzle 4 Cement tank 41 Limestone fine powder tank 42 Cement tank weighing tank 43 Limestone fine powder tank weighing tank 44 Quantitative supply hopper for coated separated raw materials 45 Dryer 46 Hot belt conveyor 47 Sorted storage tank for dried recycled aggregate 4 Drying the treated recycled aggregate fractional reservoir 49 Drying the treated regeneration aggregate fractional storage tank 5 dry burners 51 fuel oil tank 52 dust collector 53 exhaust fan A collection truck B ship track P metering pump a air vibrator

Claims (3)

  General waste incineration ash recycle characterized by being classified and classified according to particle size and coated with cement and limestone fine powder using an admixture based on formalin condensate of melamine sulfonate aggregate 2. The general aggregate according to claim 1, wherein the particle size is classified into 5 mm or less, greater than 5 mm and less than 10 mm, and more than 10 mm and less than 15 mm, and produced into concrete aggregate for secondary products. Waste incineration ash recycled aggregate By spraying and humidifying general waste incineration ash, which is free from foreign substances, and sorted according to particle size, with a mixed aqueous solution composed mainly of a formalin condensate of melamine sulfonate, and mixed with cement and fine limestone powder by a mixer A method for producing general waste incinerated ash recycled aggregate characterized by drying after coating

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