JPH036334A - Method for briquetting granular metal - Google Patents

Abstract

PURPOSE:To facilitate briquetting and to provide water resistance by adding specific amounts of organic natural material or thermosetting resin to a granular metal, mixing the above, and subjecting the resulting mixture to pressure molding and to heating treatment. CONSTITUTION:A mixture is prepared by adding, by weight, 0.1-10% organic natural material or 0.1-5% thermosetting resin to a granular metal, which is mixed and pressure-molded, followed by heating treatment at about 50-200 deg.C. As the organic natural material, wheat flour, barley flour, rye flour, flying-out flour, starch powder, etc., are used. The thermosetting resin is selected from urea resin, melamine resin, phenolic resin, and copolycondensation resins thereof. By this method, high-degree water resistance can be provided to the resulting molded materials, and outdoor storage is made possible. Further, strength under normal conditions directly after molding can be improved, and improvement in yield in post-process can be expected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is intended to effectively utilize fine metal powder, etc. recovered from iron ore powder and various slags as a raw material for iron making, steel making, etc. The present invention relates to a method for making a material into a form that is easy to handle and has water resistance.

[Conventional technology]

Fibrous and linear materials are easy to handle because they can be agglomerated simply by compression molding, but finer powder-like metals cannot be agglomerated by simply being compressed.

The following method is generally used to agglomerate such fine powdery metal.

Namely, ■A method using an inorganic binder such as cement or bentonite.

■Method using polyvinyl alcohol or carboxymethyl cellulose.

■Method using starch.

■Method using molasses, tar, and ethylene bottom.

■Method using polyurethane thermosetting resin.

■Method using phenolic resin.

etc.

[Problem to be solved by the invention]

The above methods (1) to (2) have various problems, and their improvement has been strongly desired.

That is, in method (2), the binder amount is approximately 10% by weight (hereinafter simply referred to as %).
) is used in large quantities, and the amount of binder increases due to the method of adding water and kneading and then press-molding, which lowers the quality of the metal and increases the sulfur (S) contained in bangu. In addition, in the case of powdered metal with oil attached, the binder does not adhere well and the normal solidification strength does not increase. Is required. In addition, since the method (2) is hardened by a hydration reaction, its drop strength is low, and it is easily cracked or powdered, making it inconvenient to handle. However, the effect is not fully demonstrated.

Next, method (2) involves adding about 0.5% binder and water and mixing and molding, but if oil and fat bones are attached, it will not harden, so it is necessary to burn it off using a kiln or other method. It is necessary to remove the greasy bone by means of.

Method (2) causes the same problem as method (2) when β-type starch is used, but when α-type starch is used, it is relatively easy to agglomerate and has good solidification strength, but it has poor water resistance. The problem is that the agglomerates cannot be stored outdoors due to the lack of water.

Furthermore, method (■) has the same problems as (2) and also seriously impairs the working environment due to its odor.

In addition, method (■) heats the raw materials to 180 to 200°C, adds 1 to 5% of binder, and mixes and molds.The binder is expensive, and if the raw materials have oil attached, the oil will vaporize during heating. Therefore, there are drawbacks such as the need to use special equipment such as a kiln.

In addition, although the method (2) has a markedly good water crushing strength after heat treatment, it has a weak normal strength, making it difficult to agglomerate, and the agglomerated material breaks in a de-firming machine, making it difficult to handle.

(Means for Solving the Problems) The present invention solves the above-mentioned problems, and provides a method that is inexpensive and can be easily agglomerated even if the raw material has oily bones attached, and that also provides water resistance. As a result of careful consideration,
It was found that more favorable effects can be obtained by adding, mixing, and press-molding an organic natural product and a thermosetting resin, followed by heat treatment, which led to the completion of the present invention.

That is, the present inventors added zero organic natural products to powdered metals.
．． The present invention relates to a method for agglomerating powdery metal, which comprises adding, mixing, press-molding, and heat-treating 1 to 10% or 0.1 to 5% of a thermosetting resin.

[Detailed disclosure of the invention]

The present invention will be explained more specifically.

The granular metal used in the present invention refers to fine granular metal recovered from iron ore powder and various slags.

An organic natural product is one that contains at least starch as a component, and the content of the starch is not particularly limited.

Such organic natural products may be wheat flour, barley flour, rye flour, fly flour, starch, or a mixture thereof.

The amount of the organic natural product added is 0.1 to 1 based on the powder metal.
0% is suitable, preferably 0.5-5%. 0.1
If it is less than %, moldability is poor and the molded product has low normal strength, making it brittle and easily broken. On the other hand, if it exceeds 10%, the water resistance will drop significantly and the loss of elution during outdoor storage will be large, which is not a good idea.

Next, examples of thermosetting resins used in the present invention include urea resins, melamine resins, phenol resins, and co-condensed resins thereof.

The urea resin used is formaldehyde (F) and urea (
U) is condensed at a molar ratio of 1.0 to 3.0 (F/ll), and melamine resin has a molar ratio of formaldehyde (F) and melamine (M) of 2 (F/M).
．． Those condensed at a ratio of 0 to 3.5, and phenol resins are those condensed at a molar ratio of formaldehyde (F) and phenol (P) of 1.0 to 3.0 (F/P). used. Further, these resins may be used by co-condensing them or simply by mixing them.

Further, these amino resins are preferably modified using a modifier such as polyvinyl alcohol, carboxymethyl cellulose, or hydroxyethyl cellulose. The reason for this is that by modifying the amino resin, an amino resin with appropriate viscosity and adhesiveness can be obtained, and the modified amino resin can provide strong solidification strength between powder and granule metals. be.

The amount of these resins to be added is suitably 0.1 to 5%, preferably 0.5 to 3%, based on the powder metal as the resin solid content. If it is less than 0.1%, the water resistance will be significantly reduced, and if it exceeds 5%, the strength of the molded product immediately after molding will be weak and it will be easily damaged, and the cost will increase, resulting in an economic disadvantage. Note that the amount of resin added is calculated in terms of solid content.

These amino resins can be used alone or in combination, and since the amino resin usually has a solid content of 40 to 80%, it may be diluted with an appropriate amount of city water. The pH value of the amino resin is kept at a pH value of 7 or more in terms of PL+meter due to the storage stability of the resin, and since it is in the alkaline region, it is kneaded with the organic natural product and powdered metal. The starch in the organic natural product is gelatinized by the alkaline properties of the amino resin, which further increases the cohesive strength, resulting in good moldability and ease of handling.

In the present invention, it is essential to use an organic natural product and a thermosetting resin together, and by meeting this requirement, not only the moldability but also the normal solidification strength immediately after molding is significantly improved, making it easier to handle in subsequent processes. Loss can be reduced, and a large economic effect can be expected.

The thus obtained kneaded product can be pressure-molded and then heat-treated to obtain even stronger fixing strength.

The pressure of pressure molding is 0.1 to 5t/c+f using a compression testing machine.
It is preferably carried out at a pressure of 1 to 3 t/c+(.The pressure of pressure molding is 0.1 t/af).
If it is less than 1, strong adhesion strength cannot be obtained and the density is not sufficient. In addition, if it exceeds 5t/cJ, both adhesive strength and density are sufficient, but it is not preferable in terms of maintenance of the compression tester.
It is also an economic loss.

The pressurization time depends on the type of organic natural product and thermosetting resin used,
It depends on the amount and molding pressure, etc., but usually 1 second to 3 seconds.
Executed in 0 seconds.

The appropriate heat treatment temperature is usually 50 to 200°C, but
Preferably, the heat treatment is performed at 100 to 150°C. If the pressing temperature is less than 50°C, the amino resin will not be sufficiently cured and sufficient water resistance and adhesion strength will not be obtained.
If the temperature exceeds 00°C, the decomposition of the amino resin will be promoted and it will not be able to exert its effectiveness as a binder.

Although the heat treatment time depends on the heat treatment temperature and the pressure of pressure molding, it is usually carried out for 10 to 40 minutes.

[Examples and comparative examples]

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Example 1 Prepare three stainless steel containers in 1, put 500 parts by weight (hereinafter simply referred to as parts) of granular iron as shown in Table 1 in each, and add the following to the granular iron: After adding 2.5 parts, 10 parts, and 17.5 parts of wheat flour (Nissin Seifun Akahana) and mixing well, add urea resin (Neiloid U manufactured by Mitsui Toatsu Chemical Co., Ltd.).
-701 (solid content 50%) was slowly added to each and mixed for about 10 minutes to obtain a mixture. Put 130 g of the mixture into a mold with a diameter of 30 mm and a height of 60 mm,
A compression tester shows that the pressure of pressure molding is 1. Pressure was applied from the top for 20 seconds to obtain Ot/c+fl to obtain a molded body of the mixture. As a result, a cylindrical specimen with a diameter of 30 mm, a height of 35 mm, and a density of 5.2 g/- was obtained.The above operations were repeated three times each, and three cylindrical specimens were prepared under the same test conditions, for a total of nine specimens. A specimen was obtained. 9 specimens at 110°
It was placed in a dryer (C) and left for 20 minutes to undergo heat treatment, and then taken out from the dryer to form a molded product. The various physical properties of the molded product were evaluated and the results are shown in Table 2.

The results showed that the material had excellent crushing, water resistance, hot and drop strength, and was sufficiently durable for practical use.

The evaluation results in Table 2 are the average values of three molded products.

Table 1 Examples 2 to 4 According to the method of Example 1, the amounts of thermosetting resin and organic natural product shown in Table 2 were added and mixed to obtain a mixture. The mixture was heat treated at the heat treatment temperature and time shown in Table 2 to obtain a molded product. The results of evaluating the various physical properties of the molded product were as shown in Table 2.

As with Example 1, the results showed that the crushing, water resistance, hot temperature and falling speed were satisfactory, and the material could withstand practical use as a raw material for steel manufacturing.

Comparative Example 1 Using the same granular soft iron as in Example 1, 7.5 parts of starch (Japan Cornstarch) and 5 parts of city water were added and mixed to 500 parts of the granular soft iron, and a A molded article was obtained by performing heat treatment at the heat treatment temperature and time shown in Table 2. The various physical properties of the molded product were evaluated and the results are shown in Table 2.

Comparative Example 2 Using the same powdered soft iron as in Example 1, 10 parts of phenolic resin (IIP-300011) was added and mixed to 500 parts of the powdered iron, and heated as shown in Table 2 in the same manner as in Example 1. A molded product was obtained by heat treatment at the same treatment temperature and time.

The various physical properties of the molded product were evaluated and the results are shown in Table 2.

Comparative Example 3 Using the same powdered soft iron as in Example 1, 7.5 parts of urea resin and 60 parts of wheat flour (boundary) were added and mixed to 500 parts of the powdered soft iron, and a Heat treatment was performed at the heat treatment temperature and time shown in Table 2 to obtain a molded product. The results of evaluating the various physical properties of the molded product were as shown in Table 2.

As shown in Table 2, the results of Comparative Examples 1 to 3 show that both the crushing strength and the hot strength are lower than those of Examples 1 to 4, and the water resistance strength is also greatly reduced, which is fatal and is not practical.

14 Note-1) Indicates the strength measured with an Olsen universal testing machine immediately after molding. Compressive strength was measured at a compression speed of 6 mm/min. The following measurements were conducted under similar measurement conditions.

After curing the molded product at room temperature for 3 days, it was placed in car water (20'C) for 2 days.
The compressive strength was measured using an Olsen universal testing machine after being soaked for 4 hours and then taken out.

After curing the molded product at room temperature for 3 days, it was placed in an electric furnace at 400'C for 10 minutes, heated, taken out, cooled to room temperature, and immediately measured using an Olsen universal testing machine.

Note-4) Dropped from a height of 2m onto a 20mm thick iron plate ◎: No damage ○: Part of the part in contact with the iron plate was damaged ×: Part of the part in contact with the iron plate was considerably damaged 173-1 /
Divide into 2.

Note-2) Note-3) [Effects of the Invention] As described in detail above, the present invention is a method for agglomerating powdery metal. Compared to conventional binders, the present invention uses a combination of organic natural products and thermosetting resins, and is further heat-treated to achieve higher water resistance, making it possible to store outdoors and store buildings such as warehouses. is no longer necessary, resulting in significant construction cost savings.

Since the powdered metal is excellent in that its normal strength can be significantly improved immediately after molding, it can be expected to greatly improve the yield in subsequent processes.

In addition, the agglomerates obtained by the method of the present invention have high strength, do not cause bumping even when directly poured into molten metal, and have a resin-coated surface, so metals, etc. It has the effect that it does not rust.

Claims (1)

[Claims] 1) Addition, mixing, and pressure molding of 0.1 to 10% by weight of an organic natural substance or 0.1 to 5% by weight of a thermosetting resin based on the powdered metal. A method for agglomerating powder and granular metal, which comprises: 2) Organic natural products include wheat flour, barley flour, rye flour, flying flour,
Claim 1 selected from the group consisting of starch powder
) method described in section. 3) The method according to claim 1, wherein the thermosetting resin is selected from the group consisting of urea resins, melamine resins, phenol resins, and co-condensed resins thereof.