WO1996017702A1

WO1996017702A1 - Method of treating foundry dust and method of recycling the product thereof

Info

Publication number: WO1996017702A1
Application number: PCT/JP1995/002513
Authority: WO
Inventors: Shigeru Yamazaki; Kenzo Hoashi; Hideo Hagiwara
Original assignee: Komatsu Ltd.
Priority date: 1994-12-07
Filing date: 1995-12-07
Publication date: 1996-06-13
Also published as: JPH08206776A

Abstract

A method of treating foundry dust characterized by classifying the foundry dust generated in the regeneration of waste foundry sand into coarse and fine powders on a classifier.

Description

TECHNICAL FIELD The method for treating a material dust and the method for reusing the product by the method

TECHNICAL FIELD The present invention relates to a method for treating a substance dust generated at the time of reclaiming a substance waste sand and a method for reusing a product produced by the treatment method.

Dorsal surgery

再生 There are two methods for reclaiming material waste sand: a method that involves a firing step during the treatment process and a method that does not.

FIG. 1 is a flow chart of an example of a method for regenerating waste wood sand having a firing step. First, after removing the hot water balls and burrs in the waste sand by magnetic force sorting, the waste sand is crushed and sieved, the remaining gala is discarded, and the lump sand is crushed again. The sieved waste sand is cultivated by fluid sintering through a stock hood and a feeder, and then passed through a fluidized cooler and a vibrating cooler to be subjected to multistage scrubbing from the sinter to be washed. You. After that, the waste sand is sized and stored in silos, and reused as recycled sand.

Then, in the flow chart of the regeneration treatment, the dust generated in the fluidized roasting and the multi-stage scrubbing process, the fine sand that could not be reused in the sizing process in the sizing process, and During the fluidized roasting, the dust that has passed through the heat exchanger is separated and collected as food dust (calcine dust).

Figure 2 shows an example of a method for reclaiming waste material sand without a firing process. It is a reproduction | regeneration processing flowchart. First, the waste sand that has passed through molding and demolding is once stored in a hopper, dried by a drier, sieved, then magnetically separated by a magnetic separator, and stored in a pool hopper.

In addition, a pulverizing step is inserted before the sieving step as necessary. Then, the waste sand is polished at room temperature by a rotary creamer, then sieved and stored in silos (stock tanks) for reuse as recycled sand.

Then, in the flow chart of the regeneration treatment, the non-reusable fine powder generated in the polishing step and the sizing step is separated and collected as a material dust.

However, there is a problem that the conventional waste dust generated by the above-mentioned waste treatment of the waste sand is discarded as it is, and the disposal thereof requires a large cost.

The present inventors have conducted intensive studies from the above, and as a result, by classifying the above-mentioned waste dust, which has been disposed of until now, into a coarse-grain fine powder portion and a differential fine-grain powder portion, We found that each has a suitable use.

That is, the regenerated sand regenerated by the processing method including the firing step is fired in the firing step to inactivate the clay component. In addition, in the reclaimed sand that has been regenerated by a treatment method that does not include the firing step, the activated clay mixed in the 铸 -type molding step remains.

For this reason, the components of the material dust separated in the above-mentioned material waste sand regeneration process are also different, and the activated clay is contained in the material dust of the fired material waste sand. Not being fired, but not being fired An active clay component is mixed in the dust.

The present inventors focused on the difference in the particle size of each of the dusts separated in each of the above-mentioned reprocessing methods and the presence or absence of an active clay component due to the difference in the particle size. A method of treating a substance dust, wherein the separated substance dust is classified into a coarse-particulate fine powder and a differential fine-particulate powder, and each of the classified fine powders is provided for a suitable use. A method for recycling the product thereby has been invented. Disclosure of the invention

In order to achieve the above object, a method for treating a material dust according to the present invention comprises: Classify into powder.

Then, the material dust generated at the time of the regeneration treatment of the material waste sand having the calcination step during the above-mentioned regenerating treatment process is classified into coarse fine powder and differential fine powder, and the average of the coarse fine powder is averaged. The particle size is set to 45 to 75 ^ m, and the average particle size of the differential fine powder is set to 5 to 20 m.

On the other hand, the material dust generated at the time of reprocessing of waste material sand that does not have a firing step during the reprocessing process is classified into coarse-grain fine powder and differential fine powder, and the average particle size of the coarse-grain fine powder Is set to 35 to 60, and the average particle size of the differential fine powder is set to 1 to 4 m.

Further, the particle size distributions of the coarse and fine powders are overlapped. The overlapping ratio of the particle size distribution is 30 to 45% by weight. In addition, coarse fine powder classified from the fired dust is used as an admixture for cement mortar, and differential fine powder is used as clay for muddy water. In addition, coarsely divided fine powder classified from non-fired food dust is used as clay for muddy water, and differential fine powder is used as a binder.

According to the above configuration, the animal dust is classified into a coarsely divided fine powder and a differential finely divided powder by being passed through a classifier. The properties of the above-mentioned material dust differ depending on whether or not a firing step is included in the process of regenerating and processing the waste material sand.

Since the dust in the case of having a firing step during the regeneration treatment step does not contain an active clay component, the coarse and fine powder has a particle size of 45 to 75 izm. It is suitably used as an admixture for compounding cement mortar, and differential fine powder has a particle size of 5 to 20 m and is suitably used as clay for muddy water.

On the other hand, since the waste dust without the firing step during the regeneration treatment process contains an active clay component, the coarsely divided fine powder has a relatively large particle size of 35 to 60 m. Even if it has a diameter, it is suitably used as clay for muddy water, and the differential fine powder has a particle diameter of 1 to 4 m and is suitably used as a binder. BRIEF DESCRIPTION OF THE FIGURES

The invention will be better understood from the following detailed description and the accompanying drawings illustrating an embodiment of the invention. The embodiments shown in the accompanying drawings are not intended to specify the invention, but merely to facilitate explanation and understanding.

In the figure,

FIG. 1 is a flowchart of an example of a method for regenerating a waste material sand having a firing step during the regenerating step. FIG. 2 is a flowchart of an example of a method for regenerating waste material sand that does not have a firing step during the regenerating process.

FIG. 3 is a flow chart showing a method for treating a dust substance according to the present invention.

FIG. 4 is a diagram showing the particle size distribution of the fired dust. FIG. 5 is a diagram showing a particle size distribution of a non-fired metal dust. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a method of treating a dust in a preferred embodiment of the present invention and a method of recycling a product by the method will be described with reference to the accompanying drawings.

An embodiment of the present invention will be described with reference to FIGS.

First, as shown in Fig. 1, a method for treating the waste dust separated from the waste waste sand by the regeneration treatment method having the step of firing the waste waste sand during the regeneration treatment process will be described.

The dusts generated in the above-mentioned process of reclaiming the waste sand were subjected to a wind classifier, and as shown in Fig. 3, the dusts were divided into coarse and fine powder having an average particle size of about 50 m and an average particle size of approximately 50 m. Divided into two-class fine powder of differential fine powder with a diameter of around 10 m.

Physical properties, chemical components, and average particle sizes of the above-mentioned food dust, coarse-grained fine powder and differential fine-grained powder, and commercially available clay (where the average particle size is 50% particle size) ) Is shown in Table 1 below. wt-vJi input r width ϊΐίΐδί ネ ¾ 丄Leh J Shin tm 6, 0 0

V L. i 0

O cc ^ 7Π Bulk specific gravity g / cm ³ Π U.0 Cϋ n U. fi 011 U, l〜U.bD

7fi c

^{S i 0} 2 1 L u 00. b /. U to 11. U U. o 丄丄, d lo. 4 l 1o. Λ U to ~ 10 c. N

^{A 1} 2 ° 3 l U study ^{F e} 2 ° 3 4. U 0.0 i Q

4, 3 c ~ (; 7 CaO 2.2 2.7 4.Γ 0.3 min MgO 2.3 2.3 2.7 0. 1.3

% κ ₂ 0 0 7 0.7 2.3 to 3.3

ig Loss ^ SI) 5, 9 1.6 4.2 4. (! to 5.6) Average particle size 61 50 10 13 In Table 1, the values of C a OM g O and K This is not a significant difference, but this is not a component that affects the performance of clay and aggregates, especially for # 20, when used as aggregate in reinforced concrete, etc., alkali-aggregate reaction. The finer powders do not contain active clay (resin) components due to the fact that they are calcined.

The particle size distributions of the above-mentioned dust, coarse-grained powder, differential fine-grained powder, and clay (tocicle) are as shown in Fig. 4. The average particle size of the animal dust was 61 m, and the average particle size of the fine powder was 50 m. -The average particle size of the differential fine powder was 10 m, and the average particle size of the commercially available fine clay was 13 m.

As can be seen from FIG. 4, the particle size distribution of the coarsely divided fine powder and the particle size distribution of the differential fine powder overlap each other within a certain range, and the overlapping ratio is as shown in FIG. In the example, it was about 40% by weight as shown by the intersection P between the vertical line at the position of the maximum diameter (40) of the finely divided powder and the graph of the coarsely divided fine powder.

Next, coarse fine powder obtained by classification from the animal dust as described above is used in cement mortar as an admixture of fine aggregate, etc. Examples of clay used for muddy water in the construction method are described below.

Experimental example (1)

Example of using coarse and fine powder

Cement, fine aggregate, and water were mixed at each ratio so that the flow value was constant, and the 28-day strength of each was measured. The results are shown in Table 2 below.

IS Aggregate C / (C + S) ¾ Water Cement Flour-Grade 28B Color

No. (s Japanese material) Weight ratio Corrected ratio 1 σ c Ρ

1 city meal £ 25 .25 0.75 187.5 245 2.03

2 Crude (100) 35 22 1.50 195 97 1.39

3 Coarse (100%) 45 29 0.98 182.5 212 1.56

4 Coarse and small abduction (100%) 50 32 0.86 173.5 242 1.59 Light color

5 M (50? (!) 30 25 1.12 185 136 1.64 Light color

6 Abduction! ¾ (30¾) 30 27 0.83 180 218 1.81 Light color

7 Animal dust (100¾) 40 26 1.15 170 129 1.51 g color

8 Dust (Ϊ00¾) 45 29 0.91 170 192 1.56 g color

9 ft object dust (100¾) 50 32 0.80 177.5 226 1.60 g color

1 0 ftft dust (70¾) 30 22 1.35 170 158 1.55 g color

1 1 ft dust (50¾) 30 25 1.07 175 212 1.67 g color

1 2 Prayer dust (30¾) 30 27 0.87 172.5 223 1.82 Note) ① Nos. 5, 6, and 10 to 12 are mixtures with sand.

② c-axis compression enemy kgZcm ² , bulk specific gravity gZcm ³ ,

Q / (C + S)% _: Cement Z (Cement + fine aggregate) XI 00 Q / (C + S)% Correction: Ratio based on sand volume,

(3) Color: The color of the finished cement mortar. “Dark color” is darker than a commercial product and looks less attractive. From Table 2 above, No. 2 to No. 3 contain 100% of fine abrasion as fine aggregate for about 1 minute, and their strength is equivalent to that of a commercial product of N 0.1. . However, C / (C + S) needs to be slightly larger than N 0.1. No. 5 to 6 is a mixture of coarse powder and sand, or No. 6 where the proportion of coarse powder is 3090 is the same semester as No. 1. Equivalent strength can be obtained in terms of the weight ratio.

For Nos. 2 to 6, the color of the resulting cement mortar is pale and good. No. 7 to 12 are fine aggregates 100% of animal dust, such as Nos. 7 to 9, are required to obtain the same strength as No. 1 by C / (C + S) needs to be increased.

No. 11 to 12 contain 50% and 30%, respectively, of animal dust, but the same strength of C / (C + S) as that of No. 1 can be obtained. Can be.

In No. 7 to 11, the color of the finished cement mortar when finished was inferior to that of N0.1, but N0.12 was pale and good.

Thus, cement mortar using commercially available sand as fine aggregate can be obtained by using coarse and fine powder as fine aggregate and mixing cement and water at an appropriate ratio. It was possible to obtain cement mortar with the same strength as.

Also, the finished color is the same, and those with a mortar strength (uniaxial compressive strength) of around 100 kg / cm ² (Table 2, No. 2, etc.) have a low bulk specific gravity and are lightweight.

In addition, as a result of the classification of the animal dust, the ig L 0 ss in the animal dust is separated toward the differential fine powder, so that the color in the til minute powder becomes pale, and therefore, Even if the coarse powder is mixed into the cement mortar, the cement mortar is not particularly increased by the coarse powder (admixture).

Experimental example (2)

Usage example of differential fine powder

• Mud clay

Ground conditions: Gravel [Groundwater (Shimizu) many] Formulation Concentration (per muddy water 1 m ³⁾

Water: 820 liters

(Per muddy water 1 m ³⁾

Enlarging agent: 2.0 to 3. O kg

Differential powder: 420-560 kg

Table 3 below shows the results of experiments conducted using differential fine powders having an average particle size of 6 m, 10 m, 18.5, and a mixture of 18.5 and 11 within the range of the above concentration. Show.

Note) ① Kasaoka clay and Tochi clay are commercially available muddy clay,

② One is not measured.

Here, the required value of commercially available clay is

Funnel viscosity: 32 to 37 seconds Specific gravity: 1.25 to 1.35

Drainage: 20 milliliters or less

It is in the range.

As shown in Table 3 above, in the case of No. 1 to 8, all required values for muddy clay were cleared. The plasticity index of No. 1 to 5 was 12.2, which was an intermediate value between commercially available Kasaoka clay and Tochikura. There is a merit that the larger the plasticity index is, the easier it is to handle.However, if the plasticity index is too large, it becomes muddy clay and is difficult to separate from water. Become. Since the plastic index of the dust before classification is 7.8, the plasticity index of the differential fine powder increases by classification.

By classifying the animal dust into an appropriate particle size in this manner, clay for muddy water having appropriate performance at each shielded construction site can be obtained.

As described above, in the case of fired mineral dust, since the active clay component is not contained in the component, the coarse powder is used as fine aggregate of cement mortar as it is. In addition, the differential fine powder could be used as the above-mentioned clay for muddy water by adding a predetermined amount of a thickener.

In the above experimental example, the average particle size of the coarse and fine powder was 50 m, and the average particle size of the fine and fine powder was 10 // m. When the coarsely divided fine powder in the case of fired food dust is used as a pongee material for mollug, if the average particle size is less than 45 m, it is too fine, and the average particle size is 75 ^ m. Anything above was not used.

Similarly, in the case of differential fine powder, the values of 1 \ '0 1 to 8 in Table 3 above are used. Thus, the particle size is 6 to 18.5 m, which is appropriate.If the particle size is less than 5 m, the clay is fine for muddy clay, and if the particle size exceeds 20 m, the specified performance is obtained. I couldn't do that.

Based on the above, the coarse-grained fine powder for use as fine aggregate for mortar has a particle size range of 45 to 75 m, and the differential fine granules for use as clay for muddy water. An appropriate range of powder particle size is 5 to 20 m.

Next, as shown in Fig. 2, a method for treating the material dust separated from the material waste sand by the regeneration method that does not burn the material waste sand during the regeneration process is shown.

The dust particles generated in the above-mentioned process of reclaiming sand are passed through an air classifier, and as shown in Fig. 3, the dust particles are mixed with coarse powder having an average particle size of about 40 m and average particle size. Is divided into two-class class of fine powder of about 2.4 m.

Figure 5 shows the particle size distributions of the above-mentioned dust and the coarse and fine powders that have been classified from now on. The 50% average particle size of the animal dust was 50 μm, the 50% average particle size of the coarse powder was 40 Oim, and the 50% average particle size of the differential fine powder was 2.4 m. Was. The weight ratio of both fine powders was 90% for 1 minute fine powder and 10% for differential fine powder. In addition, the particle size distribution of the classified coarse fine powder and the particle size distribution of the differential fine powder overlap each other within a certain weight range, and the overlapping ratio is different from that of the differential fine powder in the embodiment shown in FIG. It was about 39% as indicated by the intersection P 'between the vertical line at the maximum diameter (18 m) and the graph of coarse powder. Next, the respective suitable uses of the coarsely-divided fine powder and the differentially finely-divided powder obtained by classifying from the dust as described above will be described.

Since the dust in this case is not calcined, active clay is mixed therein. Therefore, both the coarsely divided fine powder and the differentiated fine powder obtained by classifying the activated clay contain active clay. From this, both of the classified fine powders have swelling properties.

For this reason, coarse and fine powder is used as clay for muddy water in the muddy shield dwelling, and differential fine powder is used as a binder.

Experimental example (3)

Example of using coarse and fine powder

• Mud clay

Ground conditions: Gravel [Groundwater (Shimizu) many]

Formulation Concentration (per muddy water 1 m ³⁾

Water: 820 liters

Coarse fine powder: 490 kg

Thickener: 1. O kg

Mixing mud properties

Specific gravity: 1.2 9

Funnel viscosity: 36 seconds

Filtration volume: 5.0 milliliters

And

The clay used for muddy water for gravel with a large amount of groundwater using conventional commercially available clay (tochikura) is shown below as a comparative example.

Comparative example

Mix concentration Water: 820 liters

Clay: 420-560 kg

Thickener: 2.0-3.0 kg

Specified value of properties of compounded mud

Specific gravity: 1.25-; I.35

Funnel viscosity: 32 to 37 seconds

Drainage: 20 milliliters or less

In the above experimental example (3), the amount of coarse and fine powder used as water and clay was determined because the coarse and fine powder used in the experiment contained the active clay component of bentonite. Is equivalent to the case of using commercially available clay, whereas even if the thickener is 1 Z 2 to 1/3 of that of commercially available clay, the specific gravity, funnel viscosity and amount of drainage are also specified. Indicated a value that falls within the value

Experimental example (4)

Usage example of differential fine powder

• Used as a binder.

The active clay content before classification of the material dust without firing in the regeneration treatment was 19.6%, whereas the active clay content in the differential fine powder after classification was 36.0%. Was.

For this reason, this differential fine powder is recycled in-house as a binder during mold molding.

In addition, the above coarse-grained powder can be used as a substitute for muddy water for lubrication at the time of boring or as a clay mixed into a grouting agent for earth anchor for ground reinforcement.

The average particle size of the coarse-grained fine powder in this experimental example is as described above. Approximately 40 m is appropriate, but less than 35 ^ m is too coarse, exceeding 60 m, and the average particle size of the coarse and fine powder used as the muddy material after all. 35 to 60 m is appropriate.

Also, the average diameter of the differential fine powder is too small to be used below 1 m and too coarse to exceed 4 m to be used as a binder, so the average particle diameter is suitably 1 to 4 m.

As a means for classifying the waste dust in each of the above embodiments, a sieve may be used in addition to an air classifier, or other known means may be used.

As described above, the particle size distribution of the differential fine powder and the particle size distribution of the coarse fine powder obtained by the classification overlap with each other within a certain weight range as described above. When the content is more than 30% by weight, the average particle size becomes too close to each other, so that the characteristics of the coarse-grained fine powder and the differential fine-grained powder cannot be obtained. Poor recovery will reduce production efficiency. From this, it is appropriate that the overlapping ratio of the two fine powders is 30 to 45% by weight.

As described above, according to the method of the present invention, the food dust is conventionally discarded by classifying the food dust into coarse and fine powder using a classifier. The use of reuse can be expanded. Then, when the coarse-grained fine powder classified from the material dust fired during the regeneration treatment process is used as the admixture for the cement cement mortar, it is compared with a commercially available admixture. As a result, the color hardly changed, and the strength was obtained equally. The mortar with a strength of about 100 kg / cm ² has a bulk specific gravity of about 70%, which is light weight. In addition, since the grain size is between sand and cement, the mortar skin surface is And improve watertightness.

In addition, when the finely divided powder obtained by the above classification is used as clay for muddy water in the muddy shield method, it can be applied as clay for muddy water to a wide range of strata including a gravel layer with high permeability. did it.

On the other hand, since the material dust that is not fired during the regeneration treatment process contains an active clay component, the coarse powder that has been classified from now on should have a larger particle size than the commercially available one. However, it can be suitably used as clay for muddy water, and because of the high content of active clay, the amount of thickener is 1/2 to 1/3 that of commercially available clay. It can be used with less and less cost.

In addition, the differential fine powder classified from this dust also contains a large amount of active clay, so that it can be effectively used as a binder during in-house recycling during mold molding. be able to.

The present invention has been described with reference to exemplary embodiments, or various changes, omissions, and additions can be made to the disclosed embodiments without departing from the spirit and scope of the present invention. Is obvious to those skilled in the art. Therefore, the present invention should not be construed as being limited to the above-described embodiments, but as including the scope defined by the elements recited in the claims and their equivalents. Must.

Claims

The scope of the claims

1. A method for treating animal dust, which comprises the step of classifying the animal dust generated during the reclaiming of animal waste sand into coarse and fine powder by a classifier.

2. The material dust generated during the reprocessing of the waste material having a baking step during the reprocessing process is classified into coarse and fine powder, and the average particle size of the coarse A method for treating animal dust, which is 5 to 75 m.

3. The material dust generated during the reprocessing of the waste material sand that has a baking step during the reprocessing process is classified into coarse-grain fine powder and differential fine powder, and the average particle size of the fine-grain fine powder is reduced to 5%. To 20; a method for treating animal dust, characterized in that:

4. The dusts generated during the reprocessing process of the waste material sand that does not have a firing step during the reprocessing process are classified into coarse and fine powder, and the average particle size of the coarse powder The method for treating animal dust is characterized in that the length is set to 35 to 60 m.

5. The material dust generated during the reprocessing process of the material waste sand that does not have a firing step during the reprocessing process is classified into coarse and fine powder, and the average particle size of the differential fine powder is determined. A method for treating animal dust, which has a length of 1 to 4 m.

6. The material dust generated during the reprocessing of waste material sand is classified into coarse and fine powder by a classifier, and the particle size distribution of both fine powder is overlapped. A method for treating animal dust, characterized by the following.

7. The method according to claim 6, wherein the overlapping ratio of the particle size distribution of the coarse-grained fine powder and the differential fine-grained powder is 0.3 to 45% by weight.

8. The material dust generated during the reprocessing of the waste material having a baking process during the reprocessing process is classified into coarse-grained fine powder and differential fine-grained powder, and the average particle size obtained by the classification A method for reusing a material dust, characterized in that coarse dust having a diameter of 45 to 75 / m is used as an admixture for cement mortar.

9. The material dust generated during the reprocessing of the waste material having a baking process during the reprocessing process is classified into coarse and fine powder, and the average particle obtained by the classification is divided into coarse powder and differential fine powder. A method for reusing animal dust, characterized in that differential fine powder having a diameter of 5 to 20 m is used as clay for muddy water.

10. The material dust that is generated during the reprocessing of waste material sand that does not have a firing step during the reprocessing process is classified into finely divided powder and differential finely divided powder, and the average particle obtained by the classification A method for recycling animal dust, comprising using coarsely divided fine powder having a diameter of 35 to 60 as clay for muddy water.

1 1. Recycling of waste waste sand that does not have a firing step during the recycling process It specializes in classifying the dust that is generated at that time into coarse-grained fine powder and differential fine-grain powder, and using the resulting differential fine-grain powder with an average particle diameter of 1 to 4 m as a binder. How to reuse animal dust.