JPH10193034A - Method for reusing molding dust - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reuse molding dust which is conventionally wasted by classifying mineral dust produced at the time of regenerating molding waste sand and using coarse or medium grain component as the aggregate for base adjusting coating material for finish casting material and fine grain component as asphalt filler. SOLUTION: The molding dust produced at the time of regenerating waste sand is classified into at least two grain diameter groups by a classifying machine. The coarse grain component or the medium grain component is used as the aggregate of the base adjusting coating material for finish coating material. The aggregate is used and the blend ratio per one batch is regulated to 600-1300g cement, 500-1200g aggregate, 50-250g additive and 200-600g water to obtain the base adjusting coating material for finish coating material. The classified fine grain component is used as the asphalt fillet. The fine grain component of 10-80% and calcium carbonate of 20-90% are blended to obtain the asphalt filler. The aggregate has porous grain surface and good water retentivity. The asphalt filler has good peeling resistance and flooding expansion ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reusing casting dust (calcina dust) generated during a process of reclaiming waste casting sand.

[0002]

2. Description of the Related Art Casting waste sand is regenerated by the flow shown in FIG. That is, after removing hot water balls and burrs from the waste sand by magnetic separation, the waste sand is crushed and sieved. The sieved waste sand is roasted by a fluidized roaster via a stock hopper and a feeder, and then subjected to a multistage scrubbing from a hopper via a fluidized cooler and a vibrating cooler. It is to be reused as.

In this regenerating process flow, dust generated in fluidized roasting and a multi-stage scrubbing process, fine-grained sand which cannot be reused in the sizing in the sizing process, and heat generated during fluidized roasting The dust that has passed through the exchanger is separated and collected as casting dust (calcina dust).

[0004]

The conventional casting dust generated by the reuse of the above-mentioned foundry sand has been discarded as it is, and there has been a problem that the disposal thereof requires a large cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a method for reusing casting dust which has been discarded until now and which is to be reused according to its particle size by classifying the dust. Things.

[0006]

The method for treating casting dust according to the present invention is directed to a method for treating casting dust generated during the recycling of casting waste sand, wherein the casting dust is classified by a classifier into at least 2 particles per particle size.
It is classified, and the coarse or medium particles are used as an aggregate of a base adjustment coating material for a finish coating material.

[0007] Using this aggregate, the mixing ratio per batch is cement: 600 to 1300 g, aggregate: 5
00 to 1200 g, admixture: 50 to 250 g, water: 20
It mix | blends to 0-600g, and obtains the base adjustment material for finish coating materials.

In addition, casting dust generated during the regeneration of foundry sand is classified by a classifier into at least two classes according to particle size, and the fine particles are used for asphalt filler.

[0009] Casting dust generated at the time of reclaiming the casting waste sand is classified by a classifier into at least two classes according to particle size,
Fine particles: 10-80%, calcium carbonate: 20
Asphalt filler was obtained at a blending ratio of ~ 90%.

According to the present invention, the casting dust is conventionally discarded by classifying it into coarse and fine grains by a classifier, or by classifying it into coarse, medium and fine grains. The use of the foundry dust for reuse as a base adjustment coating material for a finish coating material or asphalt filler can be increased.

When the above-mentioned medium-grain fraction after 3 classification or coarse fraction after 2-classification is used as an aggregate of a base adjustment coating material for a finish coating material, the particle surface is more porous than a commercially available material. Therefore, since water retention is good, workability at the time of application can be improved. In addition, since the sintering process is performed, the dimensional change at the time of finishing is small.

Further, by using the fine particles after the above-mentioned two-class classification for the asphalt filler, the asphalt filler was able to obtain good results in both the peeling resistance and the swelling expansion coefficient.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(Example 1) Casting dust was classified into 2 and the average particle size was 65μ.
The base adjustment coating material C-1 of the base adjustment coating material for finish coating material was prepared using the coarse particles of m. The test piece was prepared by applying 150 g / m ² of a three-fold solution of manol acrylate to the test substrate with a brush, and after 24 hours, applying a mortar kneaded and mixed according to JISA 6916 to a thickness of 1 mm.

Mixing ratio per batch of test specimen Cement: 1000 g Casting dust (coarse particles): 800 g Admixture: 140 g Water: 395 g

Test results Softness change: 10.5% Crack resistance: no cracks Impact resistance: no cracks and peeling Bonding strength after standard curing: 25.5 kg / cm ² Bonding strength after low-temperature curing: 6 0.1 kg / cm ² water absorption: 0.3 g

(Example 2) Casting dust was classified into 3 parts, and a base adjusting material C-1 as a base adjusting material for a finish coating material was prepared using a medium particle having a particle size of 53 to 106 µm. The test condition is the same as in Example 1.

Compounding ratio per batch of test specimen Cement: 1000 g Casting dust (medium particle size): 800 g Admixture: 140 g Water: 500 g

Test results Softness change: 6.7% Crack resistance: no cracks Impact resistance: no cracks and peeling Bonding strength after standard curing: 14.3 kg / cm ² Bonding strength after low-temperature curing: 5 0.1 kg / cm ² water absorption: 0.6 g

Example 3 Asphalt filler was prepared by classifying casting dust into two parts and using fine particles having a particle size of 106 μm or less.

Mixing ratio of test specimens Calcium carbonate: 80% Casting dust (fines): 20%

Test result Moisture: 0.21% Plasticity index: NP Flow: 37.5% Peeling resistance: Accepted Water swelling coefficient: 2.80% Heat deterioration: None

The blending ratio per batch of the test specimen in the above-mentioned Example 2 is as follows when shown within the allowable range. Cement: 600 to 1300 g Cast dust: 500 to 1200 g Admixture: 50 to 250 g Water: 200 to 600 g

[Brief description of the drawings]

FIG. 1 is a flowchart of a process for regenerating casting waste sand.

Claims (4)

[Claims] Claims 1. Casting dust generated at the time of reclaiming waste casting sand is classified by a classifier into two or three classes according to particle size, and coarse particles at the time of the second classification or medium particles at the time of the third classification are separated. A method for reusing casting dust, which is used as an aggregate of a base adjustment coating material for a finish coating material. 2. Using the aggregate according to claim 1, the mixing ratio per batch is cement: 600 to 1300 g, aggregate: 500 to 1200 g, admixture: 50 to 250 g,
Water: A method for reusing casting dust, which is prepared as a base adjustment material for a finish coating material by mixing the water to 200 to 600 g. 3. A method for reusing casting dust, wherein casting dust generated during the regeneration of foundry sand is classified by a classifier into two particles by particle size, and the fine particles are used for asphalt filler. 4. Casting dust generated during regeneration of foundry waste sand is classified by a classifier into at least two classes according to particle size. Fine particles: 10 to 80%, calcium carbonate: 20 to
A method for recycling casting dust, characterized in that asphalt filler is blended at 90%.