JP6200179B2 - Mixed raw materials for producing reusable granulate from waste - Google Patents

Description

  The present invention relates to a mixed raw material for producing a reusable granulated material from waste.

  Conventionally, as disclosed in, for example, Japanese Patent Application Publication No. 2006-315890 or Japanese Patent Application Publication No. 2008-137842, a reusable granulated product is manufactured from waste (waste material). ing. After the earthquake that occurred in 2011, in the disaster area, for example, in the disaster waste disposal business (Minamisanriku treatment area), granulation treatment is performed to improve the recycling rate of the waste generated from the disaster waste ing.

  In the facility construction stage after the earthquake, cleaning residues (dehydrated cake from soil cleaning facilities) and non-combustible residues are used as raw materials for granulation. In addition, since it is difficult to secure a receiving destination for incinerated main ash generated after incineration of mixed combustibles, incineration main ash is also required to be used as a raw material for granulation.

  However, since incinerated main ash contains a relatively large amount of harmful substances such as lead, it is not possible to produce granulated material with incinerated main ash alone, and when incinerated main ash is mixed with other raw materials, It is necessary to optimize (limit) the mixing ratio in light of environmental standards. In addition, as a mixed raw material for reusable granulated material containing incinerated main ash, it is necessary to satisfy environmental standards such as elution suppression of harmful substances.

JP 2006-315890 A JP 2008-137842 A

  The present invention aims to provide a reusable granulated raw material (mixture) containing incinerated main ash generated after incineration of mixed combustibles, and more specifically, harmful substances including lead in particular. An object of the present invention is to provide a raw material (mixture) of a granulated product capable of suppressing elution.

  The present invention provides a mixed raw material for producing a reusable granulated material from waste. The mixed raw materials are a dehydrated cake generated from a soil washing facility, an incombustible material having a size of 6 mm or less generated from a debris granulation pretreatment facility, an incineration main ash generated from an incineration facility of a combustible mixture, cement, And a predetermined insolubilizing agent, and the incinerated main ash is contained at a ratio of 30 wt% or less.

  According to the present invention, incinerated main ash can be reused as a granulated raw material by including incinerated main ash in a proportion of 30 wt% or less in a mixed raw material for producing a reusable granulated product from waste. At the same time, it is possible to suppress the ratio (elution amount) of lead, which is a harmful substance, in the granulated product after granulation of the mixed raw material to an environmental standard or less.

  In one embodiment of the present invention, as a predetermined insolubilizer, ferrous sulfate (for example, 0.5 to 1.0 wt%), magnesium oxide (for example, 2 to 5 wt%), and a chelating agent (for example, 0.2 -1.0 wt%).

  According to one aspect of the present invention, elution of harmful substances (hexavalent chromium, arsenic, fluorine, lead) in the granulated product after granulation of the mixed raw material can be suppressed to an environmental standard or less.

It is a figure which shows the process of manufacturing the reusable granulated material using the mixture of this invention. It is a figure which shows the relationship between the ratio of the incineration main ash in the granulated material of one Embodiment of this invention, and lead content.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a process for producing a reusable granulated product according to an embodiment of the present invention. The manufacturing process of FIG. 1 should be carried out, for example, using the equipment of an intermediate treatment facility that recycles construction waste (for example, “Zero Emi Plant” owned by the applicant, Eiwa Kogyo Co., Ltd.). Can do.

  In step S1 of FIG. 1, a dehydrated cake generated from a soil washing facility is prepared. Specifically, for example, as a dehydrated cake, the residue under the sieve generated from the earthquake debris sorting facility and the tsunami deposit earth and sand (for example, the size of 40 mm or less) were washed at the soil washing facility, and the regenerated sand was taken out. Prepare a dehydrated and solidified residue of the later mud.

  In step S2, an incombustible material having a size of 6 mm or less generated from a debris granulation pretreatment facility is prepared. Specifically, for example, non-combustible materials (concrete waste, natural stone, bricks, glass, ceramics, tiles, etc.) generated from the earthquake debris sorting facility are obtained by crushing and sorting in the pre-granulation facility. Prepare a non-combustible material with a size of 6 mm or less.

  In step S3, incineration main ash generated from the incineration facility for the combustible mixture is prepared. Specifically, for example, main ash corresponding to bottom ash is prepared as incinerated main ash from residues obtained by incineration of the combustible mixture generated from the debris sorting facility. In this step S3, the particle size of the incinerated main ash is adjusted. The measured lead content in the incinerated main ash was 500 mg / kg or less, more specifically, about 350 to 450 mg / kg. Prior to the subsequent mixing step, a chelating agent, which is an additive for insolubilizing lead, may be sprayed (added) to the incinerated main ash in advance.

  In step S4, the prepared dehydrated cake, the incombustible material having a size of 6 mm or less, and the incinerated main ash are mixed to prepare a raw material (mixture) of the granulated product. At that time, cement corresponding to the solidifying material and a predetermined additive are added. The predetermined additive is added to suppress the elution of harmful substances (insolubilization). In addition, you may add a dewatering cake, cement, and a predetermined | prescribed additive in a subsequent granulation process.

  Predetermined additives include the above-described chelating agent as an additive for insolubilizing lead, ferrous sulfate for insolubilizing hexavalent chromium, arsenic, fluorine, and magnesium oxide for insolubilizing lead . For each additive, the amount of elution from the granulated product after granulation is based on the environmental standards (the “Enforcement Regulations of the Soil Contamination Countermeasures Law” (Ministry of the Environment Ordinance No. 29 dated December 26, 2002). ) In a predetermined amount (ratio) so as to be less than. The predetermined amount (ratio) is 0.5 to 1.0 wt%, 2 to 5 wt%, 0.2 to 1 in order of ferrous sulfate, magnesium oxide, and chelating agent with respect to 5 to 15 wt% of cement. 0.0 wt%. It was found that when each additive was added in these proportions (ranges), the above environmental standards could be satisfied (below).

  In step S5, a granulated product is produced by granulating in a granulator while adding an appropriate amount of water to the mixture obtained in mixing step S4. The particle size of the granulated material changes depending on the rotation speed, rotation time, etc. of the blades of the granulator, and the proportion of the granulated material having a large particle size can be increased by increasing the rotation time (ie, granulation time). it can.

  In step S6, quality control of the generated granulated material is performed. Quality control inspects / confirms whether the granulated product meets specifications (grain size, environmental standards, etc.) suitable for the application. The granulated material that has passed the inspection is, for example, mixed with recycled concrete (RC) 40 at a predetermined ratio and reused as a granulated crushed stone in a roadbed or the like.

  FIG. 2 is a diagram showing the relationship between the proportion of incinerated main ash and the lead content in the obtained granulated product. Graph A in FIG. 2 is a result obtained from an actual measurement value of the lead content (mg / kg) in the granulated product actually produced. FIG. 2 shows that in order to suppress the lead content to 150 mg / kg or less which is an environmental standard, it is necessary to suppress the ratio of incinerated main ash in the mixture which is a raw material of the granulated material to 30 wt% or less. It was. Furthermore, it was found that it is more desirable to suppress the ratio of incinerated main ash to about 20 wt% or less in consideration of variations in lead content and the like.

A plurality of samples (granulated products) were actually manufactured by changing the mixing ratio, and quality evaluation was performed. As a result, as an example, in a granulated product produced using a mixture mixed at a mixing ratio (wt%) shown in the following table, harmful substances defined by environmental standards (cadmium, hexavalent chromium, cyanide, It was confirmed that the amount of elution of lead, arsenic, fluorine, etc.) can be kept below the value determined by environmental standards.
<Mixing ratio (wt%)>

  Embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to these embodiments. The present invention can be implemented in variously modified, modified, and modified embodiments based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

Claims (5)

A mixed raw material for producing reusable granulated material from waste,
Dehydrated cake generated from soil washing facilities,
Incombustible material of 6mm or less in size generated from the debris granulation pretreatment facility,
Incineration main ash generated from incineration facilities of combustible mixture,
Cement,
A predetermined insolubilizing agent,
A mixed raw material comprising the incinerated main ash in a proportion of 30 wt% or less.   The mixed raw material according to claim 1, wherein the predetermined insolubilizer includes ferrous sulfate, magnesium oxide, and a chelating agent.   The cement, the ferrous sulfate, the magnesium oxide, and the chelating agent are sequentially 5 to 15 wt%, 0.5 to 1.0 wt%, 2 to 5 wt%, 0.2 to 1.0 wt%. The mixed raw material according to claim 2, which is contained in a ratio of   The mixed raw material according to any one of claims 1 to 3, comprising the incinerated main ash at a ratio of 20 wt% or less.   The granulated material obtained by granulating the mixed raw material of any one of Claims 1-4.

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