JPH03127677A - Far infrared radiating material - Google Patents

Abstract

PURPOSE:To widely utilize waste foundry sand which has been discarded in the fields of far IR industry by using the sand for the thermal spraying material, sintered body, coating, civil and construction material, etc. CONSTITUTION:The <=100-mesh fine powder in the recovered foundry sand after injection of molten iron cannot be used as the foundry sand. The waste foundry sand consists essentially of SiO2, ZrO2, Cr2O3, Fe2O3, Al2O3 and MgO, and the sand is widely applied even in the non-heating fields (health appliances, clothing, water-activating machine, freshness retention, prevention of road surface freezing, etc.) as well as in the heating fields (heating, room heating, drying, cooking and sauna appliances, etc.). The sand is used for the flame coating material, sintered body, coating and civil and construction material. Accordingly, the sand can be widely used in the fields of heaters and civil and construction material such as road repairing asphalt base material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to far-infrared radiating materials, particularly for far-infrared ray heaters used in heating, drying, food processing, etc., health appliances, freshness preservation, and plants. Advantageous for use in non-heating fields that provide far-infrared effects for cultivation, civil engineering and construction substrates, for seawater desalination plants in dry regions such as deserts and areas with low rainfall, and for road paving materials in areas with frozen surfaces in winter. Regarding applicable materials.

[Conventional technology]

The molding sand (foundry sand) used to make castings is recovered and recycled after pouring molten metal into it.
When recovered and recycled, sand corresponding to fine particles of 100 mesh or less in the recovered sand is excluded because if reused as foundry sand, it will cause casting defects (mould breakage, gas defects, sand mold, etc.). However, this excluded fine sand has no other use and is said to cause industrial pollution if left untreated.
All foundries are struggling with how to dispose of the waste.

The amount of sand reaches 2 to 5% of the foundry sand, and in many cases, this high sand is hardened with powder or cement, solidified, and disposed of at a location or area agreed with the local government, and then the sand is poured over it. etc. is covered. In some local governments, it is mandatory to plant trees on top of this soil cover in order to prove that there is no pollution, and in some cases, wells are dug deep underground in several places around the disposal site to check whether pollutants have leached into the well water. In some cases, there is a measurement reporting obligation.

[Problem to be solved by the invention]

In view of the above-mentioned state of the art, the present invention proposes an effective use of foundry sand, which is in the form of a fine powder and cannot be reused as foundry sand.

[Means to solve the problem]

As a result of intensive research into the physical properties of cast Takasago, the present inventors found that
The following findings were obtained.

Casting Takasago (hereinafter referred to as Takasago) is 5i02.Zr0i
+Crz, Al2O5, Pew's, and MgO are the main components, and an analysis example is shown in Table 1.

As a result of measuring the far-infrared emissivity of these Takasagos, it was found that they are highly efficient far-infrared emitters.

Figure 1 shows an example of Takasago's far-infrared radiation curve.

In addition, harmful substances that can cause pollution that affect the human body from this Takasago are determined according to the national "Waste Disposal and Cleaning Law (Judgment Standards for Industrial Waste Containing Metals, etc.)" and local governments. Hyogo prefecture.

All standards have been cleared in Kobe City's ``Guidelines for Proper Treatment of Industrial Waste and Waste Containing Heavy Metals, etc.''.

Table 2 shows examples of sample weighing methods and analysis items.

Table The present invention was completed based on the above findings, focusing on the fact that Takasago is a highly efficient far-infrared radiating material. Far-infrared radiation substances that have been confirmed to be effective can be used in heating fields (heating, space heating, drying, food cooking,
It is widely used as a material for far-infrared heaters in saunas and other equipment), as well as in non-heating fields (health equipment, clothing, water activators, freshness preservation, road antifreeze prevention, etc.)
The application is also being expanded to

The present invention has discovered that Takasago has highly efficient far-infrared radiation characteristics as shown in example 1.2 in Figure 1, and utilizes this as a far-infrared radiation material that can be applied to heating and non-heating fields. , this Takasago is processed and utilized for use as coating materials, sintered bodies, paints, and base materials for civil engineering and construction.

In the present invention, Takasand is processed depending on the application, but prior to processing, it is necessary to roast and remove the foundry sand adhesive material (for example, furan resin, etc.) adhering to the surface.

Processing methods depending on the purpose of use are shown below.

■ Thermal spray coating material Takasago is sorted through a sieve, and the fine powder with a particle size of less than 100 μm is used as a coating material for thermal spraying such as plasma spraying, gas spraying, and arc spraying.

As shown in FIG. 2, this coating material is applied to the heater 3. A far-infrared heater can be obtained by thermally spraying a thermally sprayed film 6 on the surface of a metal tube or metal plate 5 containing an insulating filler 4.

■ Add β-alumina sol to sintered Takasago as a binder at 1~5%wt%.
After blending and kneading well with a kneading machine such as a ball mill, kneader, or continuous mixer, it is formed into a shape according to the purpose (ball, cube, flat plate, disk, etc.), dried at room temperature, and then heated in a sintering furnace to 1200~
Sinter at 1500°C. In this case, it is preferable to use an atmosphere-controlled furnace (referred to as an atmosphere furnace) as the sintering furnace.

This sintered body emits far-infrared rays with high efficiency when heated by a heat source such as electricity, gas, kerosene, charcoal, hot water, etc., and exhibits the far-infrared effect. However, as shown in Fig. 3, it can also be installed by burying it around the roots of plants, potted plants, vegetables and fruits such as strawberries, etc., to achieve the effect of growing and promoting their growth. In addition, in Figure 3, 7 is a transparent glass aquarium, 8 is a daikon radish,
9 is Takasago sintered body, 10 is water, and 11 is rock wool.

■ Paint Takasago is sorted through a sieve, and the fine powder finer than 100 mesh is used as the base material for paint. Paint adhesive (matrix)
As the material, organic silicon, epoxy, fluororesin, water glass, etc. are used. The base material composition is preferably in the range of 20 to 60%. When applied to the inner surfaces of pots, frying pans, and kettles, this paint emits far-infrared rays when heated, shortening boiling time and improving cooking efficiency. On the other hand, it is said to improve taste.

Also, by applying it to the inside of the bathtub, a fine powder of 100 μm to 100 mesh of civil engineering and construction material fine sand can be used.

This is mixed with asphalt and used as road equipment.
Furthermore, by efficiently combining geothermal heat and hot spring heat using heat pumps, etc., highly efficient far-infrared rays are emitted from the road surface, which melts snow and frost, making it possible to create roads with less freezing in the winter. In addition, when repairing an asphalt road mixed with this high sand, this asphalt has good heat softening properties, which improves the workability of road repair C. (When repairing asphalt roads, the process of heating the road surface and softening the asphalt using a road heater (the name of the road repair machine) is usually incorporated.) [Example 1] Inside A paint using Takasago (100 μm or less) as a base material and silicone as an adhesive is applied and baked. (Pour the same amount of water into a treated iron container and an untreated iron container, and heat with an electric heat source of the same capacity.) It was heated and the time taken to reach the boiling point was measured.

As a result, as shown in Table 3 below, the water in the Takasago coating-treated container reached boiling temperature 1.5 times faster than that in the untreated container.

[Example 2] The Takasago sintered body 9 of the present invention was lined up at the bottom of the transparent glass container 7 shown in FIG. did.

Seeds of Kaiware radish 8 were sown on this rock wool 11. On the other hand, a glass container 7 of the same type was filled with water 1O and rock wool 11 was placed therein, and seeds of Kaiware radish 8 were sown therein.

As a result of comparing the growth and yield of Kaiware radish with and without Takasago sintered body, as shown in Table 4 below, we were able to clearly recognize differences in growth height and yield as shown in Table 4. .

[Example 3] The far-infrared radiation curve from the heater surface coated with the Takasago coating of the present invention is shown in FIG.
In both cases of 400°C, far infrared rays are emitted with high efficiency.

[Example 4] FIG. 4 shows a far-infrared radiation curve 13 of asphalt mixed with 20% of Takasago of the present invention. 12 shows the spectrum curve of only asphalt as a reference, and the spectrum curve of only asphalt is shown as a reference. It can be seen that the Takasago asphalt of the present invention has an improved absorption rate, thereby improving the heat absorption rate. A spectral absorption curve 14 of water is shown for reference.

[Effects of the Invention] The effects of the present invention are that casting Takasago, which conventionally had to be disposed of as industrial waste in a specific place or region under legal regulations, can be used as a far-infrared radiator, and can be used in a wide range of far-infrared industries. This means that it can be used effectively. Furthermore, most foundries in Japan currently use foundry sand [silica sand (Si)], which is the material for molds.
L) Zircon sand ZnO/Si mouth, chromite sand (Cr
20a/S 102) Magnesia (IJgO) etc.] are expensive and imported from overseas, and the amount is several liters per year.
Reaching 00,000 tons. Therefore, utilizing cast Takasago as a highly efficient far-infrared emitting material with high added value will bring great national benefits and be a good idea.

That is, the present invention makes it possible to apply cast Takasago over a wide range of fields such as heaters and civil engineering and construction materials such as road repair asphalt base materials.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the far-infrared radiation curve of cast Takasago, which is the basis of the present invention. Figure 2 is a diagram showing how cast Takasago is used in the configuration of a far-infrared heater. Figure 3 is a diagram showing how to use cast Takasago for growing Kaiware radish. A diagram showing the arrangement of the used cast Takasago sintered body,
FIG. 4 is a chart showing the spectral absorption rate of asphalt mixed with cast iron Takasago.

Claims (1)

[Claims] A far-infrared emitting material characterized by being made of foundry waste sand.