JP5420475B2 - How to recycle foundry sand - Google Patents

Description

  The present invention relates to a method for reclaiming foundry sand, and more particularly to reusing sand after shot blasting.

  Conventionally, in the manufacture of castings, mold sand adheres to the casting surface of the casting after mold release. Therefore, the attached sand is removed by shot blasting to clean the casting surface to obtain a casting product.

  By the way, the sand removed by shot blasting as described above is disposed of as industrial waste for a fee. This processing cost has been rising year by year, and it has a large impact on corporate profits. Also, it is difficult to secure a disposal site from the viewpoint of environmental protection.

  Therefore, conventionally, a method has been proposed in which the sand removed from the casting is applied to a magnetic separator, and the sand from which the magnetic material has been removed by this magnetic separator is used as reclaimed sand (for example, see Patent Document 1).

JP 2003-290870 A

  However, in the method described in Patent Document 1, sand removed from the casting by shot blasting is applied to a magnetic separator, and the sand from which the magnetic material has been removed by this magnetic separator is intended to be reused as recycled sand. Since recycled sand of various sizes is mixed, it cannot be reused as sand for creating a mold as it is. In other words, a mold for casting a large product needs to release a large amount of gas generated during pouring so as not to adversely affect the molded product to be cast. Is required. On the other hand, a mold that casts a small and precise molded product has a small amount of gas generated, and it is not necessary to consider the influence of the mold, but instead it is necessary to increase the surface density of the molded product. , Fine grained sand is required. For this reason, when the foundry sand is reused, there is a problem that sand having a particle size corresponding to the mold of the molded product to be cast must be obtained, which cannot be achieved by the conventional method.

  The present invention has been devised to solve the above-mentioned conventional problems. By reusing sand that has been removed from the casting by shot blasting and has been disposed of in the past, the cost for disposal can be reduced. It is possible to provide a recycling method of foundry sand that can protect the environment by securing a disposal place and can easily obtain sand having a particle size according to the type of mold of a molded product to be cast. Objective.

In order to solve the above-mentioned problem, a method for reclaiming foundry sand according to the present invention is a method for reclaiming cast sand after mold release, wherein the sand removed from the cast by shot blasting is subjected to a magnetic separator, The fine sand is removed from the removed sand, the sand from which the magnetic substance and fine powder have been removed is introduced into the particle size separator, and the sand separated by the particle size separator is collected in the sand recovery unit according to the particle size, and this recovered recycling Of the sand, reclaimed sand having a particle size suitable for the purpose is selectively carried into the molding line, and the reclaimed sand and green sand are mixed together at a predetermined ratio, and the reclaimed sand is at least one of the sand forming the mold. The magnetic material separated from the sand by the magnetic separator is recovered in the magnetic material recovery unit and used as a casting return material or a steel material return material, and the collected fine powder is used as a binder. It is what.

According to this invention specific matter, sand that has been disposed of in the past can be reused as reclaimed sand, and it is possible to reduce costs and protect the environment, which are required for disposal, and to be cast. It is possible to easily obtain sand having a particle size according to the mold.
Further, a finer reclaimed sand can be obtained by the fine powder removing step of removing fine powder from the sand from which the magnetic material has been removed.

The method for reclaiming foundry sand according to the present invention is a method for reclaiming cast sand after mold release, wherein the sand removed from the cast by shot blasting is applied to a magnetic separator, and the magnetic substance and fine powder are removed by this magnetic separator. The sand from which the magnetic substance and fine powder have been removed is introduced into the particle size separator, and the sand separated by the particle size separator is collected in the sand collecting section according to the particle size. Recycled sand having a suitable particle size is selectively carried into a molding line, and the regenerated sand and raw sand are mixed and mixed at a predetermined ratio, and the reclaimed sand is used as at least part of the sand forming the mold, A magnetic material separated from sand by a magnetic separator is recovered in a magnetic material recovery part and used as a casting return material or a steel material return material, and the collected fine powder is used as a caking material.

  According to the casting sand recycling method of the present invention, sand that has been disposed of in the past can be reused as recycled sand, and it is possible to reduce the cost of the disposal and to protect the environment. Thus, sand having a particle size corresponding to the type of mold of the molded product to be cast can be easily obtained. Further, by adding a fine powder removing step for removing fine powder in the reclaimed sand, it is possible to obtain reclaimed sand of higher quality.

It is the schematic which shows the reproduction | regeneration apparatus for enforcing the reproduction | regeneration utilization method of the foundry sand of this invention.

  Hereinafter, an embodiment of a method for reclaiming foundry sand according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a regenerator for carrying out the method for reclaiming foundry sand according to the present invention.

  In FIG. 1, 1 is a shot blast for removing sand adhering to a casting. Even after the casting has been removed by a sand spreader, the sand still adheres to the casting surface, and thus the attached sand needs to be removed by the shot blast 1. There are many types of shot blasting 1 such as a hanger type, tumbler type, table type, barrel type, and ram cage type.

  Reference numeral 2 denotes a supply device that supplies the shot A with the cast A with the sand after mold separation adhered to the casting surface to the shot blast 1. The cast A supplied into the shot blast 1 by the supply device 2 is the shot blast. After sand is removed from the casting surface by 1, it is carried out of the machine from a carry-out section (not shown).

  On the other hand, the sand S removed from the casting surface by the shot blasting 1 is introduced into the external magnetic separator 4 by the introduction device 3 through, for example, the upper discharge unit 11.

  The magnetic separator 4 is for separating the magnetic substance F1 (cast iron) from the sand S. The sand S introduced into the magnetic separator 4 by the introduction device 3 is converted into the sand S1 and the magnetic substance F1 by the magnetic separator 4. To be separated.

  The separated sand S1 is introduced into a particle size separator 5 provided below the magnetic separator 4. The particle size separator 5 is for separating the sand S1 introduced from the magnetic separator 4 according to particle size. In this embodiment, the sand S1 is separated by the particle size separator 5 into three types of reclaimed sand S2, S3 for each particle size, such as a large reclaimed sand S2, a medium regenerated sand S3, and a small regenerated sand S4. , S4.

  The three types of reclaimed sand S2, S3, S4 separated in this way by the particle size separator 5 are individually collected by the sand collecting units 6, 7, 8 arranged in parallel below the particle size separator 5. The

  On the other hand, the magnetic body F1 separated from the sand S by the magnetic separator 4 is recovered to the magnetic body recovery unit 9 provided below the magnetic separator 4.

  The three types of recycled sand S2, S3, S4 collected by the above method can be used individually. Moreover, the magnetic body F1 collected by the magnetic body collection unit 9 can be used as a casting return material or a steel material return material. Thereby, the sand to be disposed of can be reused more effectively, and further cost reduction and environmental protection can be achieved.

  As a specific mode of use, for example, recycled sand having a particle size suitable for the purpose is selectively carried into the molding line from among the recycled sands S2, S3, and S4 and mixed with raw sand at a predetermined ratio. In addition, this is used for producing a core and a main mold constituting the mold. In particular, it is preferably used for producing a self-hardening core or the like.

  That is, the sand S1 removed from the casting surface of the casting by the shot blast 1 is subjected to the same treatment as the so-called roasting treatment by the projecting action of an abrasive such as a shot by an impeller in the shot blast 1. Therefore, by removing the magnetic substance F1 from the inside, it has a function of fully utilizing as recycled sand.

  Further, by adding a fine powder removing process for removing fine powder contained in the sand to the regenerating process as described above, it is possible to obtain even higher quality reclaimed sand S2, S3, S4. This step may be performed simultaneously with the separation of the magnetic substance F1 by the magnetic separator 4 by incorporating, for example, a blower in the magnetic separator 4, or the fine powder may be separately removed from the recycled sand S1 from which the magnetic substance F1 has been separated. Good. The collected fine powder can be used as a binder for foundry sand.

  Thus, by separating the magnetic material F1 from the sand removed from the casting and reusing it as recycled sand S2, S3, S4, sand that has been disposed of in the past can be effectively reused and discarded. It is possible to reduce costs for processing and protect the environment by securing a disposal place, and it is possible to easily obtain sand having a particle size corresponding to a mold of a molded product to be cast.

  In the above-described embodiment, the example in which the sand S1 is separated into three types according to the particle size by the particle size separator 5 is shown. However, the present invention is not limited to this. It may be separated as described above. In short, the sand S1 may be separated by the particle size separator 5 so as to correspond to the type of particle size required for the recycled sand.

  The method of reclaiming foundry sand according to the present invention can reduce costs and protect the environment by separating and reusing the sand removed by shot blasting according to the particle size, and can also mold a molded product to be cast. It is applied to easily obtain sand having a particle size according to the kind of the material.

DESCRIPTION OF SYMBOLS 1 Shot blast 2 Supply apparatus 3 Introduction apparatus 4 Magnetic separator 5 Grain size separator 6 7 8 Sand collection part 11 Discharge part F1 Magnetic body S Sand removed from casting S1 Sand from which magnetic body F1 was removed S2, S3, S4 Regeneration sand

Claims (2)

A recycling method for casting sand after mold release,
The sand removed from the casting by shot blasting is applied to a magnetic separator, fine powder is removed from the sand from which the magnetic material has been removed, and the sand from which the magnetic material and fine powder have been removed is introduced into the particle size separator and separated by the particle size separator. The collected sand is collected in the sand collection section according to the particle size, and the regenerated sand of the particle size suitable for the purpose is selectively carried from the collected reclaimed sand to the molding line, and the reclaimed sand and fresh sand are in a predetermined ratio. The recycled sand is used as at least part of the sand forming the mold, and the magnetic material separated from the sand by the magnetic separator is recovered in the magnetic material recovery part to be used as a casting return material or a steel material return material. A method for reclaiming foundry sand , wherein the collected fine powder is used as a caking additive . A recycling method for casting sand after mold release ,
The sand removed from the casting by shot blasting was applied to a magnetic separator, the magnetic material and fine powder were removed by this magnetic separator, and the sand from which the magnetic material and fine powder had been removed was introduced into the particle size separator and separated by the particle size separator. Sand is collected in the sand collection unit according to particle size, and the reclaimed sand having a particle size suitable for the purpose is selectively carried from the collected reclaimed sand to the molding line, and the regenerated sand and fresh sand are mixed at a predetermined ratio. Mix and match, use recycled sand as at least part of the sand that forms the mold, collect the magnetic material separated from the sand with the magnetic separator in the magnetic material recovery part, and use it as casting return material or steel material return material And a method for reclaiming foundry sand , wherein the collected fine powder is used as a binder .

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