WO2020235391A1 - Procédé de remise en production de sable de moulage - Google Patents

Procédé de remise en production de sable de moulage Download PDF

Info

Publication number
WO2020235391A1
WO2020235391A1 PCT/JP2020/018936 JP2020018936W WO2020235391A1 WO 2020235391 A1 WO2020235391 A1 WO 2020235391A1 JP 2020018936 W JP2020018936 W JP 2020018936W WO 2020235391 A1 WO2020235391 A1 WO 2020235391A1
Authority
WO
WIPO (PCT)
Prior art keywords
sand
particles
polishing
roasting
mold
Prior art date
Application number
PCT/JP2020/018936
Other languages
English (en)
Japanese (ja)
Inventor
浩 牧野
証一 村田
陽輔 高井
駿一 佐藤
勝太 堀
Original Assignee
伊藤忠セラテック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 伊藤忠セラテック株式会社 filed Critical 伊藤忠セラテック株式会社
Priority to JP2020130284A priority Critical patent/JP7487037B2/ja
Publication of WO2020235391A1 publication Critical patent/WO2020235391A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose

Definitions

  • the present invention relates to a method for regenerating cast sand, and more particularly to a method capable of regenerating cast sand advantageously from a mold molded using an inorganic binder containing water glass as a main component.
  • the mold As one of the molds used for casting molten metal, it has been known that the mold is formed into a desired shape by using casting sand made of fire-resistant particles (aggregate) and a predetermined binder.
  • a binder (binder) for binding casting sand an organic binder mainly composed of resins such as phenol resin and furan resin, and an inorganic binder mainly composed of water glass, clay, etc. are used. ing.
  • 63-180340 states that old sand of casting sand containing a combustible binder (resin) is roasted in a fluidized roasting furnace. Therefore, a method has been clarified in which the combustible binder is burned and then regenerated by a mechanical method as needed.
  • Japanese Patent Laying-Open No. 2016-150368 describes a mold molded into a predetermined shape by using a mold binder-containing sand containing an aggregate and a binder derived from artificial sand and / or natural sand. A method of regenerating the mold waste sand generated after casting as raw material sand for the mold by roasting and then dry polishing has been clarified.
  • a novolak phenol resin is used as a binder and the mold is used. It has been clarified that by producing sand containing a binder for use (RCS) and subjecting it to a regeneration step, an effect of suppressing a reduction in the desired mold strength can be obtained.
  • Japanese Patent Application Laid-Open No. 2015-51446 a mold formed by using an inorganic binder such as sodium silicate is crushed after casting, and then mixed and stirred in water at 5 ° C to 70 ° C.
  • a method for regenerating the casting sand which comprises separating the inorganic binder adhering to the casting sand, and then recovering the casting sand from which the binder has been separated and heating and drying the casting sand, has been clarified, and further, Japanese Patent Application Laid-Open No. 2016-147287.
  • Japanese Patent No. 5401325 as a method for thermally regenerating the foundry sand, the used foundry sand to which water glass is attached is heat-treated at a temperature of at least 200 ° C., and the hydrochloric acid consumption of the foundry sand is reduced.
  • a method for carrying out such a heat treatment so as to reduce the amount to 10% has been clarified, but it is assumed that such a thermal regeneration treatment is repeatedly carried out.
  • the water glass firmly adhering to the foundry sand gradually accumulated, and when the heat treatment was performed so that the hydrochloric acid consumption was reduced to 10%, a large amount of water glass was found in the foundry sand. It is thought that it will remain.
  • the refractory particles used for molding the mold together with the predetermined binder are natural sand such as silica sand and the conventional regeneration method as described above is applied, in the roasting step, thermal cracking due to thermal expansion occurs.
  • the problem that the particles themselves are crushed will be caused, so it is practical for natural sand whose durability that can withstand the regeneration process cannot be recognized. It was extremely difficult to carry out such regeneration.
  • a mechanical regeneration method such as polishing is adopted for the regeneration of cast sand made of natural sand to which inorganic binders that cannot be easily burned and removed by roasting operation are adhered, pulverization of natural sand is caused. Therefore, it was extremely difficult to regenerate the cast sand from the mold using natural sand and an inorganic binder.
  • the present invention has been made in the context of such circumstances, and the problem to be solved thereof is that after casting a mold molded using an inorganic binder containing water glass as a main component. Therefore, it is an object of the present invention to provide a practical method for regenerating the foundry sand used for molding such a mold, and another problem is that a high mold strength is maintained even by repeated reclaiming treatment.
  • the purpose is to provide an effective method for regenerating foundry sand.
  • the present invention can be preferably carried out in various aspects as listed below, but each aspect described below can also be carried out in any combination. , Can be adopted. It should be noted that the aspects or technical features of the present invention are not limited to those described below, and can be recognized based on the invention idea that can be grasped from the description of the entire specification. Should be understood.
  • a method for regenerating the foundry sand from a mold formed by using an artificially produced foundry sand made of spherical fireproof particles and an inorganic binder mainly composed of water glass is used as (a). While crushing the used mold recovered from the casting process using the mold, the crushing step of separating and removing the fine powder generated there, and (b) sizing the crushed material taken out from the crushing step.
  • polishing surface polishing treatment is performed, Regeneration of cast sand characterized by having a polishing step of separating the crystallized water glass component on the sand surface and collecting and removing the separated crystallized water glass component with a dust collector.
  • the sizing sand is mechanically polished to further crush the fixed particles existing in the sizing sand into smaller pieces. It is characterized by having a pre-polishing process in which a part of the water glass component adhering to the sand surface is separated, and the separated water glass component is collected and removed by a dust collector.
  • the above-described embodiment characterized in that the sized sand used in the roasting step has fluidity in a fluidity test after hot treatment under the roasting treatment conditions.
  • the method for regenerating cast sand according to any one of (1) to (3).
  • Al 2 O 3 in which the artificially produced spherical refractory particles are 40% by weight or more.
  • such a mold is constructed from those used in the casting process of a mold molded by using an inorganic binder containing water glass as a main component.
  • artificially produced spherical fire-resistant particles are used as the casting sand instead of natural sand such as silica sand, and the used mold recovered from the casting process is crushed and sized. Then, the obtained sized sand is roasted to crystallize the water glass component adhering to the sand surface, and then the crystallized water glass component on the sand surface is separated and removed by mechanical polishing.
  • the particles of the foundry sand itself could be effectively prevented from being crushed and refined, and the water glass component adhering to the surface of the foundry sand could be advantageously removed. Even if the casting sand is repeatedly regenerated, it has become possible to maintain a high strength of the mold formed from the regenerated sand.
  • the sizing sand is mechanically polished to further crush the fixed particles existing in the sizing sand into smaller pieces and adhere to the sand surface.
  • a pre-polishing process that separates and removes part of the water glass component, and as artificially produced spherical fireproof particles, spherical firing artificially produced by the sintering method.
  • the forming particles the characteristics of the present invention can be exhibited even more advantageously, and in particular, such spherical sintered particles, particularly mullite or mullite corundum spherical sintered particles, can be used.
  • the mold strength of the regenerated sand that has been repeatedly regenerated can be made higher than the mold strength when the new sand is used, and the feature that the strength can be effectively maintained can be exhibited. ..
  • FIG. 5 is a process schematic diagram showing various regeneration methods applied to the pseudo-old sand of the refractory particles B and C in the second embodiment, respectively.
  • the mold to which the regeneration method according to the present invention is applied is molded by using casting sand and a binder in the same manner as in the conventional case.
  • the binder is water glass.
  • the casting sand is not natural sand such as silica sand, but artificially produced spherical fire-resistant particles, which regenerates the casting sand. It could be done in an advantageous way.
  • any known refractory artificial particles can be used as the target.
  • any known refractory artificial particles can be used as the target.
  • the spherical fire-resistant particles obtained by the sintering method have fine irregularities on the particle surface. Since the inorganic binder component enters there and gradually fills up, the mold strength is about the same as that of fresh sand, and even better than that, when it is repeatedly reused as recycled sand. Since it can be expressed, it will be preferably used.
  • the spherical artificial sand (aggregate) used in the present invention advantageously has a chemical composition of 40% by weight or more of Al 2 O 3 and 60% by weight or less of SiO 2. It is desirable to be.
  • the content of Al 2 O 3 is less than 40% by weight, in other words, when the content of SiO 2 exceeds 60% by weight, the thermal expansion of the refractory particles becomes large, which is peculiar to SiO 2. Anomalous expansion is evoked, and thus the problem of self-destruction is evoked in the process of regeneration according to the present invention.
  • refractory particles (aggregates) made of a mullite or mullite corundum material are preferably used in such a chemical composition.
  • the mullite-corundum quality means a state in which the crystal structure of mullite and the crystal structure of corundum coexist or are dispersed in the particles.
  • Al 2 O 3 is preferably contained in an amount of 50% by weight or more, more preferably 60% by weight or more in order to advantageously achieve the object of the present invention.
  • a ratio of about 90% by weight, preferably 80% by weight, and more preferably about 70% by weight is generally adopted.
  • SiO 2 is preferably contained in a proportion of 50% by weight or less, more preferably 40% by weight or less, and the lower limit thereof is generally 10% by weight, preferably 20% by weight, still more preferably about 30% by weight. The ratio of is adopted.
  • the chemical composition of Al 2 O 3 : 50 to 80% by weight and SiO 2 : 50 to 20% by weight is advantageously adopted, and further, Al 2 O 3 : 60 to 70% by weight and SiO 2 : 40 to 30% by weight are adopted.
  • the chemical composition of% will be more preferably adopted.
  • such a chemical composition can be easily measured using, for example, a general fluorescent X-ray analyzer.
  • the spherical artificial sand used in the present invention has an average particle size similar to that of the refractory particles conventionally used for molding a mold, and the average particle size is generally 0. It has a size of about 01 to 0.50 mm, preferably about 0.05 to 0.40 mm, and more preferably about 0.07 to 0.30 mm. If the average particle size of this artificial sand becomes too small, it will be difficult to handle it, and it will be difficult to regenerate the recovered sand. If the particle size becomes too large, the recovered sand will be regenerated. In addition to the problem of quality deterioration of cast products, it also causes the problem of deterioration.
  • the average particle size means the particle size (D 50 ) at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method.
  • the artificial refractory particles used as such casting sand are composed of particles exhibiting a spherical shape, and the roundness thereof is generally preferably 0.70 or more, particularly 0.75 or more.
  • spherical refractory particles having a roundness of 0.80 or more will be advantageously used.
  • the roundness of the artificial refractory particles can be measured by a known method, and can be measured by, for example, a particle shape measuring device manufactured by Microtrac Bell Co., Ltd .: PartAnSI.
  • a particle shape measuring device manufactured by Microtrac Bell Co., Ltd .: PartAnSI.
  • Such a device is composed of a sample cell, a strobe LED and a high-sensitivity CCD camera, and its measurement principle is that water is circulated by a pump while a sample (fireproof particles) is charged to form a strobe LED light source and a CCD camera. Water mixed with sample particles passes through the sample cell arranged between and, and the projected area and maximum ferret diameter for each particle are obtained by image analysis of the projected image obtained at that time. Is.
  • sodium silicate which has been conventionally used as a binder or a binder in a composition for mold production, is preferably used. It will be used.
  • the casting sand and the inorganic binder as described above are mixed and kneaded according to a conventional method to form kneaded sand, and then the kneaded sand is used to mold a mold having a desired shape. Then, after casting a predetermined molten metal using the mold, the used mold recovered from the casting process is subjected to a predetermined regeneration treatment. A crushing step of obtaining crushed sand (crushed product) is carried out by crushing the used mold and separating and removing the fine powder generated therein.
  • the used mold is crushed in the crushing step by using a known crusher such as a jaw crusher, and the fine powder generated there is separated and removed by a dust collector or the like to obtain a crushed product.
  • the pyroclastic sand is taken out.
  • the fine powder to be separated and removed generally has an average particle size of about 10 ⁇ m or less.
  • the crushed sand thus obtained is subjected to a sizing (classification) operation using a sieve or the like in order to take out particles having a predetermined size, whereby the sizing sand having a predetermined particle size is taken out. It becomes.
  • the average particle diameter of the spherical refractory particles (new sand) used for molding the mold from the crushed sand which is the sizing object is 1/10 or less, preferably 1/7.
  • fine particles having an average particle diameter of more preferably one-fifth or less are removed.
  • the sizing sand taken out in the above-mentioned sizing step is generally effective as particles having a particle size of 5 mm or less, preferably 3 mm or less, which is equal to or larger than the particle size of spherical refractory particles (shinsuna).
  • the particle size of the spherical fireproof particles (new sand) is the particle size of each particle, but when such particles have a particle size distribution, practically, the average of the particles having such a particle size distribution.
  • a particle size of about 1/3 of the particle size, preferably about 1/2 of the particle size is adopted. Finer particles than spherical refractory particles (new sand) are fine powder generated when crushed and contain a large amount of active water glass components.
  • the sized sand having a predetermined particle size obtained through the crushing step and the sizing step as described above is subjected to a roasting treatment, a heat treatment, and a water glass adhering to the sand surface.
  • the components will be crystallized.
  • a fluidized bed furnace is generally used for this roasting process, and a method of applying a heat load while flowing sand in the furnace is adopted.
  • water glass which is the main component of the inorganic binder, exists in the water-containing form represented by Na 2 O, nSiO 2 , mH 2 O in the inorganic binder-coated sand used for molding the mold, and is present at the time of molding.
  • the roasting temperature in the roasting process the consuming ⁇ -Na 2 Si 2 O 5 is required to be equal to or higher than a temperature of generating is further heated at 800 ⁇ 870 °C, ⁇ -Na 2
  • the roasting temperature needs to be below that temperature because the melt of Si 2 O 5 and silicate will be formed. This is because when a melt is generated, poor fluidization or melt solidification may occur due to the presence of the melt during heating in a fluidized roasting furnace or a rotary kiln.
  • the roasting temperature adopted in the roasting treatment according to the present invention is generally 500 ° C. or higher, preferably 600 ° C. or higher, and the roasting treatment time is generally 10 minutes or longer, preferably 10 minutes or longer. Is used for more than 30 minutes, which inactivates the active water glass component remaining on the surface of the sized sand particles and kneads it with an inorganic binder when it is reused as recycled sand. It is possible to keep the pot life of the product (composition for molding) long.
  • the roasting temperature is less than 500 ° C. or the roasting treatment time is less than 10 minutes, a sufficient heat load is applied to inactivate the active water glass component adhering to the surface of the casting sand particles.
  • the sand in the roasting furnace becomes Generally, the roasting temperature is 800 ° C. or lower, preferably 750 ° C. or lower, and the roasting treatment time is generally 5 hours or less, preferably 5 hours or less, because fusion and fluidization defects are caused. Less than 3 hours will be adopted.
  • the sizing sand is mechanically polished to further crush the fixed particles existing in the sizing sand into smaller pieces.
  • a pre-polishing step of separating a part of the water glass component adhering to the sand surface and collecting and removing the separated water glass component with a dust collector is preferably adopted. ..
  • the sizing sand taken out in the sizing step is further subjected to the sizing action, and the isolation of the particles is promoted. Therefore, in the subsequent roasting step. Sufficient fluidity can be ensured, and heat load can be applied more efficiently.
  • the remaining water glass component prevents the sand (recovered sand) before regeneration from becoming particles of a desired size only by the crushing operation. Due to the accumulated water glass component, the particles are fixed to each other and a plurality of particles are integrated, and it is possible to obtain particles of a desired size by simply crushing (dissolving) the particles. This cannot be done, and as a result, problems such as insufficient heat transfer will occur in the subsequent roasting process. Therefore, the pre-polishing process as described above is adopted to crush the fixed particles, and further. It is desirable to partially remove the accumulated water glass component.
  • the surface polishing treatment is carried out by mechanically polishing the sized sand that has been subjected to the roasting treatment, and the crystallized water glass existing on the sand surface is performed. While the components are separated, a polishing step of collecting and removing the separated crystallized water glass components by a dust collector is carried out. In this polishing step, it is necessary to remove the water glass component adhering to the particle surface, which has been crystallized by the roasting (heating) treatment, and therefore, it is more than the mechanical polishing in the preliminary polishing step described above.
  • the fire-resistant particles used as casting sand need to have high crush resistance enough to withstand such mechanical polishing. Therefore, in the present invention, artificially produced spherical refractory particles are used as such refractory particles.
  • the mechanical polishing in the polishing step as described above can be carried out by using various known polishing devices together with the mechanical polishing in the preliminary polishing step described above.
  • the sized sand is brought into contact with the grindstone and its surface thereof.
  • a polishing device for polishing which is advantageous in that polishing is performed by supplying and contacting the peripheral surface of the cylindrical grindstone that is rotated around the axis with sized sand.
  • the method so as to be used will be preferably adopted.
  • 2016-413 can be used, and a commercially available sand fresher (Kiyota Casting Machine Co., Ltd.) can be used. In addition to this, polishing equipment called rotary reclamers, sand shiners, etc. can also be used. Further, although it is practically desirable that the mechanical polishing in the pre-polishing step and the mechanical polishing in the polishing step are performed by using the same polishing device, it is also possible to use different polishing devices. It is also possible to carry out each mechanical polishing.
  • the polishing action on the sized sand is considered to be mild in the pre-polishing step, while a heavy polishing action is added in the subsequent polishing step. Will be done.
  • the difference in the polishing action is realized by making the polishing time, the number of times of polishing, etc. different.
  • the mechanical polishing treatment time in the pre-polishing step may be shorter than the mechanical polishing treatment time in the subsequent polishing step.
  • the number of mechanical polishing treatments in the pre-polishing step is set to a small number, for example, one, while the number of mechanical polishing treatments in the subsequent polishing step is set to a larger number, for example, three times. Is possible.
  • fine powder of water glass component is generated by the mechanical polishing treatment, and such fine powder is prepared by the polishing treatment. It is separated from the grain sand, collected by a dust collector, and removed from the system. If fine powder is mixed in the sized sand that has been polished in the pre-polishing process, problems such as a decrease in fluidity and adhesion between the sands in the subsequent roasting process will occur. In addition, when the fine powder of the crystallized water glass component separated from the mechanically polished sized sand is mixed in the polishing step, the recycled sand obtained through such a polishing step is regenerated. This is because it becomes difficult to sufficiently realize characteristics such as mold strength at the time of use.
  • the foundry sand obtained through the crushing step, the sizing step, the pre-polishing step adopted as necessary, the roasting step, and the polishing step is regenerated.
  • the water glass component adhering to the surface thereof is effectively removed, and further, the effect of removing the water glass component adhering to the surface is advantageous even by repeated regeneration treatment of the casting sand.
  • the strength of the mold is effectively increased, and the recycling operation is repeated. It has become possible to maintain a high mold strength even in a mold using the regenerated sand obtained.
  • refractory particles A, B and C of various materials were prepared according to the known production methods shown in Table 1 below, respectively.
  • an inorganic binder containing water glass as a main component (Czech Republic: Geopol W11 manufactured by SAND TEAM) and a curing accelerator (Czech Republic: Geotek W303 manufactured by SAND TEAM) were added.
  • Three types of kneaded sand for molding were produced by mixing and kneading at the ratios shown in Table 2 below.
  • each of them is heat-treated at 150 ° C. for 1 hour to imitate the old sand (casting sand) recovered from the used mold.
  • each of the three types of pseudo-old sand obtained corresponding to the refractory particles A, B and C was crushed by a jaw crusher, and the fine powder generated at that time was removed by a dust collector.
  • the crushed product obtained by such a crushing operation is classified by a vibrating sieve to remove excessive particles and small particles, and has a particle size in the range of 105 ⁇ m to 2 mm3. Seed sized sand was removed.
  • the average particle size of the fine particles generated when crushed by the jaw crusher is 6.29 ⁇ m
  • the average particle size of the small particles removed by the vibrating sieve. was 43.1 ⁇ m.
  • These average particle diameters were obtained by measuring with a particle diameter distribution measuring device: MT3300EXII manufactured by Microtrac Bell Co., Ltd. From this, the fine particles removed by the dust collector are extremely fine, whereas the fine particles removed by the vibrating sieve are the particles broken by the above crushing operation or the water glass component adhering to the particle surface. However, it is recognized.
  • each of the three types of sized sand taken out was sequentially subjected to a roasting treatment (600 ° C. ⁇ 2 hours) and a mechanical polishing treatment (30 minutes), so that each sized sand was obtained.
  • a roasting treatment 600 ° C. ⁇ 2 hours
  • a mechanical polishing treatment (30 minutes)
  • the roasting process is carried out using a fluidized roasting furnace, while as a mechanical polishing process, 30 kg of pseudo old sand is transferred to a sand fresher (BR-305 manufactured by Kiyota Casting Machine Co., Ltd.), which is a polishing machine.
  • the grindstone (grinding stone diameter: 305 mm) is rotated at a high speed of 40 m / sec and brought into contact with the outer peripheral surface thereof, the pseudo old sand is polished and the water glass attached to the pseudo old sand is attached.
  • a dust collector Pulse jet dust collector manufactured by Amano Co., Ltd .: PiF-75U in which the removed inorganic binder-derived substance (fine powder) is connected to the sand fresher while separating and removing the substance derived from the inorganic binder mainly composed of ), A method of collecting dust at an air volume of 46 m 3 / min and removing it was adopted.
  • Example 2- Adopting the same conditions of crushing, sizing, roasting treatment and mechanical polishing treatment as in Example 1, various types of pseudo-old sand of the refractory particles B and C are shown in FIG. 1, respectively.
  • the regeneration operation was carried out according to the regeneration method of (1), and various recycled refractory particles were obtained.
  • the polishing treatment time is 10 minutes
  • the polishing treatment time after the roasting treatment is shorter than 30 minutes
  • a light polishing treatment is performed. Made to be implemented.
  • the regenerated refractory particles were respectively subjected to an inorganic binder (Geopol W11) containing water glass as a main component and a binder thereof in the composition shown in Table 3 below.
  • a curing accelerator (Geotek W303) is mixed and kneaded, and the obtained kneaded sand is further applied to a molding machine (KMTPZ1019 manufactured by Kiyota Casting Co., Ltd.) under the condition of air blow: 1.5 seconds / 0.4 MPa.
  • a molding machine KMTPZ1019 manufactured by Kiyota Casting Co., Ltd.
  • the obtained various test pieces were stored for 1 hour in an environment of temperature: 25 ° C. and humidity: 50% RH, respectively, and then using a vertical electric measuring instrument (MX2-2500N manufactured by Imada Co., Ltd.).
  • the bending strength was measured at a span of 150 mm and a descent speed of 5 mm / min, and the results are shown in Table 4 below.
  • the regenerated refractory particles (sand) obtained in the regenerating method (1) consisting of only polishing the sized sand are before being used for molding the mold. Although it exhibits a bending resistance equal to or higher than that of fresh sand, which is a refractory particle, since the active water glass component still remains on the particle surface, molding of kneaded sand after kneading sand and binder. It was judged to be impractical because the pot life, which is the possible time, was shortened.
  • the regenerated refractory particles obtained in the regeneration method (2) in which only the sizing sand is subjected to the roasting treatment and the regeneration method (3) in which the polishing treatment is followed by the roasting treatment Furthermore, the regenerated refractory particles obtained in the regeneration method (4), which consists of performing roasting treatment and polishing treatment without collecting dust or sizing when crushed, are more resistant than fresh sand. It only gave a test piece with low folding strength.
  • Example 3- The pseudo-old sands of the refractory particles B and C obtained in Example 1 were subjected to various regeneration treatments shown in Table 5 below, respectively, and the obtained recycled refractory particles were subjected to hot fluidity.
  • the test was carried out.
  • the hot fluidity test is carried out by leaving a refractory container containing each regenerated refractory particle in an electric furnace preheated to a predetermined temperature of 400 to 800 ° C. for a predetermined time of 10 to 60 minutes. , A predetermined heat treatment was performed.
  • the refractory container was taken out of the furnace, and immediately the refractory container was tilted to evaluate whether or not the regenerated refractory particles could be discharged from the refractory container. Then, the sand contained therein can be discharged only by tilting the fireproof container, which is evaluated as ⁇ , and the sand contained therein cannot be discharged only by tilting the fireproof container, but the fireproof container cannot be discharged. Those that could be discharged by hitting were evaluated as ⁇ , and those that could not discharge the contained sand from the refractory container were evaluated as ⁇ , and the results are shown in Table 5 below.
  • both the refractory particles B and C have poor hot fluidity from the heat treatment at 400 ° C. Is recognized.
  • the hot fluidity at 400 ° C. is improved, the hot fluidity from 500 ° C. is poor. Is recognized. This deterioration in hot fluidity also causes poor flow during the roasting process, indicating that sufficient roasting process cannot be performed. Therefore, the dust collection process causes fine particles. It is understood that sufficient hot fluidity cannot be exhibited only by removing the powder.
  • the size of the fine powder and fine particles that cause deterioration of hot fluidity is as follows:
  • the average particle diameter is about 6 ⁇ m in the crushing / dust collecting treatment, and the average particle in the sizing treatment.
  • the diameter is about 40 ⁇ m. Since all of them adversely affect hot fluidity, it is desirable to remove them as much as possible, and fine powders and fine particles having an average particle size of generally 20 ⁇ m or less, preferably 30 ⁇ m or less, and more preferably 45 ⁇ m or less. It is desirable to remove it.
  • Example 4- About the obtained kneaded sand after kneading sand and an inorganic binder with respect to the regenerated refractory particles obtained by the method (1) or (6) for regenerating the old sand of the refractory particles B and C in Example 2. , An evaluation test of the pot life, which is the time when the mold can be molded, was carried out. Here, in the evaluation test of the pot life, the regenerated refractory particles, the inorganic binder, and the curing accelerator are blended in the blending ratios shown in Table 3 above and kneaded, and then the obtained kneaded sand is mixed.
  • the refractory particles B and C can be filled with fresh sand and the regenerated refractory particles obtained by the regeneration method (6) even if the storage time is 2 hours. There is almost no change in comparison with the case where the usage time is 0 hours, and it is recognized that the usage time is sufficient.
  • the regenerated refractory particles obtained by the regenerating method (1) in which the regenerating treatment is performed only by the polishing treatment cannot form a test piece at a storage time of 1 hour, and therefore, the pot life is insufficient. Therefore, it is recognized that it is not practical as a reproduction method.
  • Example 5- Regeneration obtained by regenerating old sand of refractory particles B and C by the regeneration method (6) adopted in Example 2 and further repeatedly performing the same regeneration treatment on the obtained refractory particles.
  • a test piece was prepared in the same manner as in Example 2 for each number of times of regeneration, and the bending strength of the test piece was measured, and the results are shown in Table 7 below.
  • the refractory particles B are subjected to the regeneration treatment by the regeneration method (6) to develop a bending strength higher than that of the fresh sand, and then the repeated regeneration treatment is carried out.
  • the bending strength there is almost no change in the bending strength, and since it has sufficient bending strength, it is used for molds made using an inorganic binder containing water glass as the main component. It was judged that repeated use and regeneration are possible in the cast sand.
  • the refractory particles C have the same anti-folding strength as Shinsuna when the number of times of regeneration is 1, but the anti-folding strength is increased by increasing the number of times of regeneration to 2 or 3 times.
  • Example 6- The crushed sand or sized sand obtained by subjecting the old sand of the refractory particles B and C obtained in Example 1 to various regeneration treatments is roasted at a predetermined temperature up to 700 ° C. for 2 hours. After the treatment, the electric conductivity (mS / m) of each roasted sand was measured, and the results are shown in Table 8 below.
  • the electrical conductivity is such that 20 g of sand and 50 g of distilled water are stirred for 30 minutes using a stirrer and a stirrer, and then the supernatant is collected by decanting to obtain a multi-water quality manufactured by Toa DK Co., Ltd.
  • the higher the roasting temperature the lower the electrical conductivity of the regenerated refractory particles, regardless of the method of the regeneration treatment. It is recognized that the higher the temperature, the more inactivated the active water glass component remaining on the particle surface. Further, when the roasting temperature is changed from 400 ° C. to 500 ° C., the electric conductivity is remarkably lowered. Therefore, by adopting a roasting temperature of 500 ° C. or higher, the active water glass component is advantageously inactivated. It is acknowledged that it can be done. This is because Na 2 O and SiO 2 contained in the water glass react with each other to generate Na 2 Si 2 O 5 , and the temperature is 500 ° C. or higher in order to sufficiently inactivate the active water glass component. It can be said that the roasting temperature of is required.
  • the regeneration treatment is only crushing or only crushing / dust collection, as is clarified in Example 3, when the roasting temperature is 500 ° C. or higher, it is hot. It can be said that the roasting process at a temperature of 500 ° C. or higher is difficult because the fluidity decreases or is lost. Therefore, the refractory particles whose regeneration treatment is only crushing or crushing / dust collection are roasted by raising the roasting temperature to a temperature at which the active water glass component can be sufficiently inactivated. Therefore, in the regeneration method, the regenerated refractory particles (regenerated) obtained by the regenerating method in which the roasting process is immediately performed from the step of crushing or crushing / dust collection without performing the granulation in the regenerating process. The characteristics of sand) are not sufficient.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Abstract

L'invention concerne un procédé efficace de remise en production, à partir du moule qui a été coulé, de sable de moulage ayant été utilisé dans la fabrication d'un moule avec un liant inorganique contenant un verre liquide comme constituant principal.　Afin de remettre en production du sable de moulage comprenant des particules réfractaires sphériques artificielles à partir d'un moule qui est fabriqué à l'aide du sable de moulage et d'un liant inorganique contenant un verre liquide comme constituant principal, les étapes suivantes sont utilisées : une étape consistant à broyer le moule qui a été utilisé et simultanément, à séparer et éliminer une poudre fine ; une étape de broyage/calibrage consistant à calibrer le produit broyé pour obtenir du sable de taille spécifique ; une étape de grillage consistant à soumettre le sable broyé/calibré ainsi produit à un traitement de grillage pour provoquer la cristallisation d'un constituant verre liquide adhérant à la surface du sable ; et une étape de polissage consistant à polir mécaniquement le sable broyé/calibré qui a été soumis au traitement de grillage pour séparer le constituant verre liquide cristallisé sur la surface du sable, puis à collecter le constituant verre liquide cristallisé ainsi séparé à l'aide d'un collecteur de poussière, puis à retirer le constituant verre liquide cristallisé séparé.
PCT/JP2020/018936 2019-05-17 2020-05-12 Procédé de remise en production de sable de moulage WO2020235391A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2020130284A JP7487037B2 (ja) 2019-05-17 2020-07-31 鋳物砂の再生方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019093664A JP2020185608A (ja) 2019-05-17 2019-05-17 鋳物砂の再生方法
JP2019-093664 2019-05-17

Publications (1)

Publication Number Publication Date
WO2020235391A1 true WO2020235391A1 (fr) 2020-11-26

Family

ID=73222622

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/018936 WO2020235391A1 (fr) 2019-05-17 2020-05-12 Procédé de remise en production de sable de moulage

Country Status (2)

Country Link
JP (2) JP2020185608A (fr)
WO (1) WO2020235391A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113426942A (zh) * 2021-06-24 2021-09-24 南阳仁创砂业科技有限公司 一种由再生材料制备铸钢用覆膜砂的方法
CN115026239A (zh) * 2022-06-16 2022-09-09 南阳仁创砂业科技有限公司 一种防止铸件粘砂和气孔缺陷的铸造用再生砂及其制备方法
CN115106479A (zh) * 2022-06-27 2022-09-27 北京仁创砂业铸造材料有限公司 一种水玻璃铸造废砂的再生方法及得到的再生砂

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114101577B (zh) * 2021-11-24 2023-12-29 北京仁创砂业铸造材料有限公司 一种铸造3d打印废砂的再生方法

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6072637A (ja) * 1983-09-28 1985-04-24 Tokyu Kk 鋳物砂処理装置
JP2001504040A (ja) * 1996-11-22 2001-03-27 フォセコ、インターナショナル、リミテッド 砂の再生
JP2010075937A (ja) * 2008-09-24 2010-04-08 Kao Corp 再生鋳物砂の製造方法
JP2010519042A (ja) * 2007-02-19 2010-06-03 アシランド−ズードケミー−ケルンフェスト ゲーエムベーハー 鋳物砂の熱的再生
JP2011025310A (ja) * 2009-06-30 2011-02-10 Itochu Ceratech Corp 球状耐火粒子及びそれからなる鋳物砂並びにそれを用いて得られた鋳型
JP2016000413A (ja) * 2014-06-11 2016-01-07 株式会社清田鋳機 鋳物砂の再生装置
JP2016150369A (ja) * 2015-02-18 2016-08-22 山川産業株式会社 人工砂及び鋳型用粘結剤含有砂
WO2016199498A1 (fr) * 2015-06-11 2016-12-15 新東工業株式会社 Procédé de régénération de sable de moulage et dispositif de régénération
JP2017533295A (ja) * 2014-09-10 2017-11-09 ヒュッテネス−アルベルトゥス ヒェーミッシェ ヴェルケ ゲゼルシャフト ミット ベシュレンクテル ハフツング ポリウレタンコールドボックス法のための二成分バインダー系
JP2018015814A (ja) * 2017-11-01 2018-02-01 トヨタ自動車株式会社 中子砂の再利用方法及び再利用装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5152324A (en) * 1975-09-02 1976-05-08 Mitsubishi Motors Corp Imonozunano saiseihoho
DE4010377A1 (de) * 1990-03-30 1991-10-02 Vnii Litejnogo Mash Verfahren zur formsandrueckgewinnung aus altsand von giessereibetrieben und system zu seiner durchfuehrung
JP6846318B2 (ja) 2017-09-12 2021-03-24 旭有機材株式会社 回収鋳物砂の再生方法

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6072637A (ja) * 1983-09-28 1985-04-24 Tokyu Kk 鋳物砂処理装置
JP2001504040A (ja) * 1996-11-22 2001-03-27 フォセコ、インターナショナル、リミテッド 砂の再生
JP2010519042A (ja) * 2007-02-19 2010-06-03 アシランド−ズードケミー−ケルンフェスト ゲーエムベーハー 鋳物砂の熱的再生
JP2010075937A (ja) * 2008-09-24 2010-04-08 Kao Corp 再生鋳物砂の製造方法
JP2011025310A (ja) * 2009-06-30 2011-02-10 Itochu Ceratech Corp 球状耐火粒子及びそれからなる鋳物砂並びにそれを用いて得られた鋳型
JP2016000413A (ja) * 2014-06-11 2016-01-07 株式会社清田鋳機 鋳物砂の再生装置
JP2017533295A (ja) * 2014-09-10 2017-11-09 ヒュッテネス−アルベルトゥス ヒェーミッシェ ヴェルケ ゲゼルシャフト ミット ベシュレンクテル ハフツング ポリウレタンコールドボックス法のための二成分バインダー系
JP2016150369A (ja) * 2015-02-18 2016-08-22 山川産業株式会社 人工砂及び鋳型用粘結剤含有砂
WO2016199498A1 (fr) * 2015-06-11 2016-12-15 新東工業株式会社 Procédé de régénération de sable de moulage et dispositif de régénération
JP2018015814A (ja) * 2017-11-01 2018-02-01 トヨタ自動車株式会社 中子砂の再利用方法及び再利用装置

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113426942A (zh) * 2021-06-24 2021-09-24 南阳仁创砂业科技有限公司 一种由再生材料制备铸钢用覆膜砂的方法
CN115026239A (zh) * 2022-06-16 2022-09-09 南阳仁创砂业科技有限公司 一种防止铸件粘砂和气孔缺陷的铸造用再生砂及其制备方法
CN115026239B (zh) * 2022-06-16 2023-11-28 南阳仁创砂业科技有限公司 一种防止铸件粘砂和气孔缺陷的铸造用再生砂及其制备方法
CN115106479A (zh) * 2022-06-27 2022-09-27 北京仁创砂业铸造材料有限公司 一种水玻璃铸造废砂的再生方法及得到的再生砂

Also Published As

Publication number Publication date
JP7487037B2 (ja) 2024-05-20
JP2021178360A (ja) 2021-11-18
JP2020185608A (ja) 2020-11-19

Similar Documents

Publication Publication Date Title
WO2020235391A1 (fr) Procédé de remise en production de sable de moulage
CN110421113B (zh) 一种由旧砂再生废弃物制备的陶粒砂及由该陶粒砂制备的覆膜砂
JP5507262B2 (ja) 鋳型用骨材粒子
CN1984734B (zh) 制备微粒耐火组合物的方法
CN110125329B (zh) 一种水玻璃旧砂的再生方法
CN110944768A (zh) 铸模材料和其制造方法、铸模的制造方法、以及回收耐火性骨料的再生方法
JP2019048329A (ja) 回収鋳物砂の再生方法
CN109320090B (zh) 一种利用含氯提钛热渣制备微晶玻璃的方法
JPH05169184A (ja) 高珪酸質球状鋳物砂及びその製造方法
JP2013188789A (ja) 人工砂およびその製造方法
JP5567353B2 (ja) 球状耐火粒子及びそれからなる鋳物砂並びにそれを用いて得られた鋳型
JP2021102216A (ja) 鋳型再生砂、レジンコーテッドサンド及び鋳型
JPH0647479A (ja) 人工鋳物砂およびその製造方法
CN112703071B (zh) 制备用于制造铸造模具和型芯的粒状耐火组合物的方法、相应的用途以及用于热处理的再生混合物
JP7142563B2 (ja) 回収砂の再生方法
JP4679937B2 (ja) 鋳物砂の製造方法
JP2965782B2 (ja) 廃珪砂を利用した人工砂の製造方法
JPH0716698A (ja) 鋳型構造
JPH08192244A (ja) 鋳造用湯口・押湯系製品
JP2013031882A (ja) 精密鋳造用鋳型製造のためのバックアップスタッコ材及びその製造方法並びにそれを用いて得られた精密鋳造用鋳型
JP5178338B2 (ja) 精密鋳造用鋳型製造のためのバックアップスタッコ材及びその製造方法並びにそれを用いて得られた精密鋳造用鋳型
JP2024018288A (ja) 無機コーテッドサンドおよびその製造方法、ならびに無機コーテッドサンドの保存安定性向上方法
CN107377867B (zh) 一种铸钢涂料及其制备方法
JP2024018294A (ja) 無機コーテッドサンドおよびその製造方法、ならびに無機コーテッドサンドの保存安定性向上方法
JP4484173B2 (ja) 不定形耐火物

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20810586

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20810586

Country of ref document: EP

Kind code of ref document: A1