An inorganic warm core box, a binder and a preparation method thereof

Abstract

The application discloses an inorganic warm core box, a binder and a preparation method thereof. The inorganic warm core box comprises 100 parts of silica sand (in percentage by weight) and 2.2-3.3 parts of a binder, wherein the binder comprises an A component and a B component, and the B component comprises passivated silicon powder. The inorganic warm core box provided by the application can effectively improve the fluidity of the mixture of silica sand and the binder. The improvement of the fluidity can improve the stability and compactness of the surface of the sand mold, and can improve the core-making effect of the complex sand core; the smoothness and size precision of the surface of the casting can be improved, and the problems such as inclusion, pore, sand eye and the like can be reduced, so that the production efficiency of the casting is improved and the economic benefits of the foundry are improved.

Description

Technical Field

[0001] This application relates to the field of adhesives for casting, specifically to an inorganic temperature core box, an adhesive, and a method for preparing the same. Background Technology

[0002] Casting binders can be divided into organic and inorganic types. Organic binders are widely used, but they generate toxic gases such as furans, dioxins, benzenes, and phenols during core making and casting, and also produce significant carbon emissions. Inorganic binders, on the other hand, have advantages such as being green and environmentally friendly, and have always been a focus of attention in the development of green casting. Among them, the inorganic warm core box process has advantages such as low heating temperature, low energy consumption, and environmental friendliness, and has received widespread attention and application in fields such as automobiles since its emergence.

[0003] Chinese invention patent CN 100531959C discloses a core-making process for modified water glass sand warm-core boxes. It uses nano-silica powder and cinder powder as modifiers. This warm-core box process can improve the working environment and reduce core box deformation. Chinese invention patent application CN 114406181A discloses a warm-core box binder and its preparation method. It adds hydrophilic cleaning fillers, corrosion-resistant and wear-resistant fillers, and aluminosilicate refractory materials to the raw materials. This formula can enhance the binder's corrosion resistance and wear resistance, and improve the adsorption of magnetic impurities in the sand particles. Chinese invention patent application CN 115533021A discloses a two-component water-soluble binder for casting warm-core boxes and its application method. Its improved components can improve bonding performance and application performance, improve collapsibility, and increase sand core strength. Chinese invention patent CN 108393430B discloses a curing agent for casting water glass. It uses an ester-based composite of ZrSiO4 thermally decomposed amorphous silica as the powder component of the core box binder. This composite has advantages such as strong adhesion, long shelf life, and ease of handling. None of the aforementioned patent documents mention improving the flowability of the binder mixed with silica sand. Summary of the Invention

[0004] To address the aforementioned issues, this application provides an inorganic core box, wherein component B effectively improves the fluidity of the mixture of silica sand and binder. This improved fluidity enhances the stability and compactness of the sand mold surface, improving the core-making effect for complex sand cores; it also increases the surface finish and dimensional accuracy of castings, reducing inclusions, porosity, and sand holes, thereby increasing casting production efficiency and improving the economic benefits for foundry manufacturers.

[0005] This application provides an inorganic temperature core box, comprising 100 parts (by weight percentage) of silica sand and 2.2-3.3 parts of binder, wherein the binder comprises component A and component B, and component B comprises passivated silica micropowder.

[0006] Furthermore, the mass ratio of component A to component B is (1.6-2.2):(0.6-1.1).

[0007] Furthermore, the particle size of the passivated microsilica powder is 5-100 μm, preferably 30-75 μm.

[0008] Furthermore, the specific surface area of ​​the passivated microsilicon powder is 0.1-2 m². 2 / g.

[0009] Furthermore, the silica content in the passivated microsilica powder is 90-99 wt%.

[0010] Furthermore, component B comprises 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate.

[0011] Further, the lignin sulfonate is one of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate; or

[0012] The mullite particles are artificial sand spherical particles with an alumina content of ≥60wt%.

[0013] Furthermore, the D50 particle size of the mullite particles is 30-100 μm; and / or

[0014] The graphite powder has a D50 particle size of 30-100 μm; and / or

[0015] The D50 particle size of the zircon powder is 30-100 μm.

[0016] Further, component A is prepared according to a formula comprising 25-40 wt% sodium silicate, 0.5-2 wt% potassium hydroxide, 0.5-2 wt% sodium aluminate, 2-10 wt% silica sol, and the balance being deionized water.

[0017] This application also provides a method for preparing the aforementioned inorganic temperature core box, comprising the following steps:

[0018] 100 parts by weight of silica sand are put into a sand mixer, and a certain proportion of component A and component B of the binder are added and mixed. The mixed molding sand is then put into the core shooter's sand shooting hopper to make the core.

[0019] This application also provides an adhesive comprising a component A and a component B, wherein the component B comprises passivated silicon micropowder.

[0020] Further, component A comprises 25-40 wt% sodium silicate, 0.5-2 wt% potassium hydroxide, 0.5-2 wt% sodium aluminate, 2-10 wt% silica sol, and the balance being deionized water;

[0021] Component B comprises 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate.

[0022] Further, the lignin sulfonate is one of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate; or

[0023] The mullite particles are artificial sand spherical particles with an alumina content of ≥60wt%.

[0024] Furthermore, the D50 particle size of the mullite particles is 30-100 μm; and / or

[0025] The graphite powder has a D50 particle size of 30-100 μm; and / or

[0026] The D50 particle size of the zircon powder is 30-100 μm.

[0027] Furthermore, the particle size of the passivated microsilica powder is 5-100 μm, preferably 30-75 μm.

[0028] Furthermore, the specific surface area of ​​the passivated microsilicon powder is 0.1-2 m². 2 / g.

[0029] Furthermore, the silica content in the passivated microsilica powder is 90-99 wt%.

[0030] This application also provides a method for preparing an adhesive, comprising the following steps:

[0031] Preparation of Component A: Component A is prepared according to the following formula: sodium silicate 25-40 wt%, potassium hydroxide 0.5-2 wt%, sodium aluminate 0.5-2 wt%, silica sol 2-10 wt%, and the balance being deionized water.

[0032] Preparation of Component B: Component B is prepared according to the following formula: 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles and 1-10 wt% lignin sulfonate.

[0033] Furthermore, the adhesive prepared by the preparation method of this application is the aforementioned adhesive.

[0034] The inorganic core box described in this application, component B, can effectively improve the fluidity of the mixture of silica sand and binder. Improved fluidity enhances the stability and compactness of the sand mold surface, improving the core-making effect for complex sand cores; it can also increase the surface finish and dimensional accuracy of castings, reducing inclusions, porosity, and sand holes, thereby improving casting production efficiency and the economic benefits for foundry manufacturers.

[0035] Component B of the binder in this application can reduce the viscosity and frictional resistance of the binder-silica sand mixture, thereby effectively improving its workability. Detailed Implementation

[0036] The following description provides exemplary embodiments of this application, including various details to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0037] This application provides an inorganic temperature core box, comprising 100 parts (by weight percentage) of silica sand and 2.2-3.3 parts of binder, wherein the binder comprises component A and component B, and component B comprises passivated silica micropowder.

[0038] In some embodiments, the silica sand content is 100 parts by weight, and the binder content is 2.2-3 parts by weight.

[0039] Specifically, the content of the silica sand is 100 parts by weight, and the content of the binder can be 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3 parts by weight, 3.1 parts by weight, 3.2 parts by weight, 3.3 parts by weight, etc.

[0040] The mass ratio of silica sand to component A is 100:(1.6-2.2), and the mass ratio of silica sand to component B is 100:(0.6-1.1). Appropriate ratios result in better core strength and surface hardness. Increasing the liquid component allows the binder to better coat the sand grains, resulting in a thicker binder film; however, excessive liquid component affects collapsibility, increases the likelihood of porosity, and also increases the economic costs for foundries. Powder materials can provide hydroxyl-rich active microsilica, which can effectively react with the liquid component and improve the water glass modulus; however, excessive powder material will accelerate the reaction, causing the silica sand mixture to dry out, drastically shortening its usable time, severely affecting the performance of the inorganic sand, and also increasing the economic costs for foundries.

[0041] Specifically, the mass ratio of the silica sand to component A can be 100:1.6, 100:1.7, 100:1.8, 100:1.9, 100:2.0, 100:2.1, 100:2.2, etc.

[0042] The mass ratio of the silica sand to component B shown can be 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:1.0, 100:1.1, etc.

[0043] The mass ratio of component A to component B can be (1.6-2.2):(0.6-1.1), which is (1.45-3.7):1. For example, it can be 1.45:1, 1.55:1, 1.65:1, 1.75:1, 1.85:1, 1.95:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, etc.

[0044] In this application, component B comprises 20-75 wt% passivated microsilica powder, preferably 30-50 wt%, more preferably 45-60 wt%, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate, preferably 5-10 wt%.

[0045] In some embodiments, component B consists of 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate.

[0046] Furthermore, in component B, the mass fraction of the passivated microsilica powder is 40wt%-60wt%. The passivated microsilica powder reacts with sodium silicate in component A at a low rate, which can reduce the rate at which the modulus of sodium silicate in liquid component A increases, thereby maintaining the spherical structure of the powder material and the thin film water layer in the silica sand mixture, thus enhancing the ball-bearing effect and improving the fluidity of the material.

[0047] In some embodiments, the passivated microsilica powder has a mass fraction of 45wt%-60wt% in component B.

[0048] In some embodiments, the passivated microsilica powder has a mass fraction of 50wt%-60wt% in component B.

[0049] In some embodiments, the passivated microsilica powder has a mass fraction of 30wt%-50wt% in component B.

[0050] Specifically, in component B, the mass fraction of the passivated microsilica powder can be 20wt%, 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, or 42wt%. %, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59 wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, etc.

[0051] In component B, the mass fraction of the graphite powder can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7. 4wt%, 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7w t%, 8.8wt%, 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0052] In component B, the mass fraction of the zircon powder can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7.4 wt%, 7.5 wt%, 7.6 wt%, 7.7 wt%, 7.8 wt%, 7.9 wt%, 8 wt%, 8.1 wt%, 8.2 wt%, 8.3 wt%, etc. 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9 .3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, 11wt%, 11 .5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt%, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, etc.

[0053] In component B, the mass fraction of the mullite particles can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7.4 wt%, 7.5 wt%, 7.6 wt%, 7.7 wt%, 7.8 wt%, 7.9 wt%, 8 wt%, 8.1 wt%, 8.2 wt%, 8.3 wt%, 8.4 wt%, 8.5 wt%, 8.6 wt%, 8.7 wt%, or 8.8 wt%. , 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9. 9wt%, 10wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt %, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt% , 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt%, 25wt%, etc.

[0054] In some embodiments, the lignin sulfonate in component B has a mass fraction of 5 wt-10 wt.

[0055] In some embodiments, the lignin sulfonate in component B has a mass fraction of 5 wt-8 wt.

[0056] Specifically, in component B, the mass fraction of the lignin sulfonate can be 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, or 2.9 wt%. , 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4wt%, 4.1wt% , 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5wt%, 5.1wt%, 5.2wt%, 5.3wt %, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5.9wt%, 6wt%, 6.1wt%, 6.2wt%, 6.3wt%, 6.4wt%, 6.5 wt%, 6.6wt%, 6.7wt%, 6.8wt%, 6.9wt%, 7wt%, 7.1wt%, 7.2wt%, 7.3wt%, 7.4wt%, 7.5wt%, 7.6wt%, 7. 7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8 .9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0057] In this application, lignin sulfonate is one of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate.

[0058] The mullite particles are artificial sand spherical particles with an alumina content of ≥60wt%.

[0059] In this application, the D50 particle size of the mullite particles is 30-100 μm, preferably 30-50 μm. For example, it can be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, etc.

[0060] The D50 particle size of the graphite powder is 30-100μm, preferably 30-50μm, and can be, for example, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0061] The D50 particle size of the zircon powder is 30-100μm, preferably 30-50μm, and can be, for example, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0062] The D50 particle size of each component in component B can better fill the tiny gaps between the silica sand, thereby improving the density and uniformity of the mixture, providing more active sites for chemical reactions, and enhancing the realization of the ball effect.

[0063] In this application, "particle size" is also referred to as "particle size" or "diameter." When a certain physical property or physical behavior of a particle being tested is most similar to that of a homogeneous sphere (or combination) of a certain diameter, the diameter (or combination) of that sphere is taken as the equivalent particle size (or particle size distribution) of the particle being tested. Particle size is generally divided into a single particle size representing the size of an individual particle and an average particle size representing a group of particles of different sizes. Since the shape of actual particles is usually non-spherical, it is difficult to directly represent their size using diameter. Therefore, in the field of particle size testing, for non-spherical particles, the equivalent particle size (generally referred to as particle size) is usually used to characterize the particle size. The equivalent particle size refers to the diameter (or combination) of a sphere (or combination) of a certain diameter that is most similar to the physical property or physical behavior of a particle being tested. In this application, the D50 particle size refers to the particle size corresponding to a sample where the cumulative volumetric particle size distribution percentage reaches 50%. Its physical meaning is that 50% of the particles are larger than it and 50% are smaller than it. D50 is also called median diameter or median particle size.

[0064] The D50 particle size was determined using a Malvern Mastersizer 3000 particle size analyzer.

[0065] In this application, the D50 particle size of the passivation microsilicon powder is 5-100 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 10-75 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 10-70 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 30-80 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 30-50 μm. For example, it can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, etc.

[0066] The specific surface area of ​​the passivated microsilica powder is 0.1-2 m². 2 / g, for example, can be 0.1m 2 / g, 0.2m 2 / g, 0.3m 2 / g, 0.4m 2 / g, 0.5m 2 / g, 0.6m 2 / g, 0.7m 2 / g, 0.8m 2 / g, 0.9m 2 / g, 1m 2 / g, 1.1m 2 / g, 1.2m 2 / g, 1.3m 2 / g, 1.4m 2 / g, 1.5m 2 / g, 1.6m 2 / g, 1.7m 2 / g, 1.8m 2 / g, 1.9m 2 / g、2m 2 / g etc.

[0067] The mass fraction of silica in the passivated microsilica powder is 90-99 wt%, for example, it can be 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, etc.

[0068] In the preparation of the warm core box, microsilica powder plays two roles. Firstly, it can polymerize with sodium silicate in the liquid component, forming a complex three-dimensional network structure, thereby promoting curing and increasing strength. Secondly, its spherical structure can transform the sliding friction between sand particles into rolling friction, achieving a ball-bearing effect and increasing fluidity. However, the rapid reaction rate of microsilica powder quickly increases the modulus of water glass, forming Si-O-Si bonds and enhancing cohesive strength, thus suppressing the ball-bearing effect of its spherical structure. Passivated microsilica powder, due to its larger particle size, fewer surface hydroxyl groups, and weaker activity, can reduce the reaction rate by up to 35%, thus better leveraging the effects of both microsilica powder and water glass, thereby improving the fluidity of the silica sand mixture.

[0069] In this paper, passivating microsilica powder is sufficient to reduce the reaction rate and thus improve the flowability of the silica sand mixture. In a specific example, microsilica powder with a particle size of 5-100 μm can be used. In another specific example, microsilica powder with a specific surface area of ​​0.1-2 m² can be used. 2 / g of microsilica powder. In a specific example, microsilica powder with a silica content of 90-99wt% can be used. In a specific example, microsilica powder with a specific surface area of ​​0.1-2m² can be used. 2 Microsilica powder with a silica content of 90-99 wt% per gram. In a specific example, a particle size of 5-100 μm and a specific surface area of ​​0.1-2 m² can be used. 2 In a specific example, the microsilica powder with a particle size of 5-100 μm and a silica content of 90-99 wt% can be used. In another specific example, the microsilica powder with a particle size of 5-100 μm and a specific surface area of ​​0.1-2 m² can be used. 2 / g, microsilica powder with a silica content of 90-99wt%.

[0070] In this application, component A comprises 25-40 wt% sodium silicate, 0.5-2 wt% potassium hydroxide, 0.5-2 wt% sodium aluminate, 2-10 wt% silica sol, and the balance being deionized water.

[0071] Specifically, in component A, the mass fraction of sodium silicate can be 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, etc.

[0072] In component A, the mass fraction of potassium hydroxide can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, etc.

[0073] In component A, the mass fraction of sodium aluminate can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, etc.

[0074] In component A, the mass fraction of the silica sol can be 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5wt%, 5.1wt%, 5.2wt%, 5.3wt%, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5 .9wt%, 6wt%, 6.1wt%, 6.2wt%, 6.3wt%, 6.4wt%, 6.5wt%, 6.6wt%, 6.7wt%, 6.8wt%, 6.9w t%, 7wt%, 7.1wt%, 7.2wt%, 7.3wt%, 7.4wt%, 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8.9wt%, 9wt %, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0075] This application provides a method for preparing the aforementioned inorganic temperature core box, comprising the following steps:

[0076] 100 parts by weight of silica sand are put into a sand mixer, and a certain proportion of component A and component B of the binder are added and mixed. The mixed molding sand is then put into the core shooter's sand shooting hopper to make the core.

[0077] In this preparation method, the specific composition and parameters of component A and component B can be referred to the above description.

[0078] This application provides an adhesive comprising component A and component B. Component A comprises 25-40 wt% sodium silicate, 0.5-2 wt% potassium hydroxide, 0.5-2 wt% sodium aluminate, 2-10 wt% silica sol, and the balance being deionized water. Component B comprises 20-75 wt% passivated microsilica powder, preferably 30-50 wt%, more preferably 45-60 wt%, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate, preferably 5-10 wt%.

[0079] This application provides an adhesive composed of component A and component B. Component A consists of 25-40 wt% sodium silicate, 0.5-2 wt% potassium hydroxide, 0.5-2 wt% sodium aluminate, 2-10 wt% silica sol, and the balance being deionized water. Component B consists of 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles, and 1-10 wt% lignin sulfonate.

[0080] Component A is a liquid component, and component B is a powder component.

[0081] The liquid component, primarily sodium silicate, dehydrates and hardens during hot air blowing, playing a key binding role. The powder component reacts with the liquid binder, increasing the binder's modulus, thereby promoting hardening and enhancing the core strength. Simultaneously, the spherical structure of the powder material enables a ball-bearing effect, promoting grain sliding, reducing solid friction, and thus improving the fluidity of the silica sand mixture.

[0082] In this application, the mass ratio of component A to component B can be any value and can be specifically set according to actual needs. For example, when the binder is used to prepare the warm core box, the raw materials of the warm core box include silica sand in addition to component A and component B. The amount of component A added is 1.6%-2.2% of the mass of silica sand, and the amount of component B added is 0.6%-1.1% of the mass of silica sand. Then the mass ratio of component A to component B is (1.6-2.2):(0.6-1.1).

[0083] Specifically, in component A, the mass fraction of sodium silicate can be 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, etc.

[0084] In component A, the mass fraction of potassium hydroxide can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, etc.

[0085] In component A, the mass fraction of sodium aluminate can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, etc.

[0086] In component A, the mass fraction of the silica sol can be 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5wt%, 5.1wt%, 5.2wt%, 5.3wt%, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5 .9wt%, 6wt%, 6.1wt%, 6.2wt%, 6.3wt%, 6.4wt%, 6.5wt%, 6.6wt%, 6.7wt%, 6.8wt%, 6.9w t%, 7wt%, 7.1wt%, 7.2wt%, 7.3wt%, 7.4wt%, 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8.9wt%, 9wt %, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0087] In some embodiments, the passivated silica powder has a mass fraction of 40wt%-60wt% in component B. The passivated silica powder reacts with sodium silicate in component A at a low rate, which can reduce the rate of increase in the modulus of sodium silicate in liquid component A, thereby maintaining the spherical structure of the powder material and the thin film water layer in the silica sand mixture, thus enhancing the ball bearing effect and improving the fluidity of the material.

[0088] In some embodiments, the passivated microsilica powder has a mass fraction of 45wt%-60wt% in component B.

[0089] In some embodiments, the passivated microsilica powder has a mass fraction of 50wt%-60wt% in component B.

[0090] In some embodiments, the passivated microsilica powder has a mass fraction of 30wt%-50wt% in component B.

[0091] Specifically, in component B, the mass fraction of the passivated microsilica powder can be 20wt%, 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, or 42wt%. %, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59 wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, etc.

[0092] In component B, the mass fraction of the graphite powder can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7. 4wt%, 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7w t%, 8.8wt%, 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0093] In component B, the mass fraction of the zircon powder can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7.4 wt%, 7.5 wt%, 7.6 wt%, 7.7 wt%, 7.8 wt%, 7.9 wt%, 8 wt%, 8.1 wt%, 8.2 wt%, 8.3 wt%, etc. 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9 .3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, 11wt%, 11 .5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt%, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, etc.

[0094] In component B, the mass fraction of the mullite particles can be 5 wt%, 5.1 wt%, 5.2 wt%, 5.3 wt%, 5.4 wt%, 5.5 wt%, 5.6 wt%, 5.7 wt%, 5.8 wt%, 5.9 wt%, 6 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, 6.5 wt%, 6.6 wt%, 6.7 wt%, 6.8 wt%, 6.9 wt%, 7 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7.4 wt%, 7.5 wt%, 7.6 wt%, 7.7 wt%, 7.8 wt%, 7.9 wt%, 8 wt%, 8.1 wt%, 8.2 wt%, 8.3 wt%, 8.4 wt%, 8.5 wt%, 8.6 wt%, 8.7 wt%, or 8.8 wt%. , 8.9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9. 9wt%, 10wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt %, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt% , 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt%, 25wt%, etc.

[0095] In some embodiments, the lignin sulfonate in component B has a mass fraction of 5 wt-10 wt.

[0096] In some embodiments, the lignin sulfonate in component B has a mass fraction of 5 wt-8 wt.

[0097] Specifically, in component B, the mass fraction of the lignin sulfonate can be 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, or 2.9 wt%. , 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4wt%, 4.1wt% , 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5wt%, 5.1wt%, 5.2wt%, 5.3wt %, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5.9wt%, 6wt%, 6.1wt%, 6.2wt%, 6.3wt%, 6.4wt%, 6.5 wt%, 6.6wt%, 6.7wt%, 6.8wt%, 6.9wt%, 7wt%, 7.1wt%, 7.2wt%, 7.3wt%, 7.4wt%, 7.5wt%, 7.6wt%, 7. 7wt%, 7.8wt%, 7.9wt%, 8wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt%, 8.5wt%, 8.6wt%, 8.7wt%, 8.8wt%, 8 .9wt%, 9wt%, 9.1wt%, 9.2wt%, 9.3wt%, 9.4wt%, 9.5wt%, 9.6wt%, 9.7wt%, 9.8wt%, 9.9wt%, 10wt%, etc.

[0098] In this application, lignin sulfonate is one of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate.

[0099] The mullite particles are artificial sand spherical particles with an alumina content of ≥60wt%.

[0100] In this application, the D50 particle size of the mullite particles is 30-100 μm, preferably 30-50 μm. For example, it can be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, etc.

[0101] 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0102] The D50 particle size of the graphite powder is 30-100μm, preferably 30-50μm, and can be, for example, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0103] The D50 particle size of the zircon powder is 30-100μm, preferably 30-50μm, and can be, for example, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0104] The D50 particle size of each component in component B can better fill the tiny gaps between the silica sand, thereby improving the density and uniformity of the mixture, providing more active sites for chemical reactions, and enhancing the realization of the ball effect.

[0105] "Particle size," also known as "particle size" or "diameter," is the equivalent particle size (or particle size distribution) of a particle when a certain physical property or behavior of the tested particle is most similar to that of a homogeneous sphere (or combination) of a certain diameter. Particle size is generally divided into single particle size, representing the size of an individual particle, and average particle size, representing the size of a group of particles of different sizes. Since actual particles are usually non-spherical, it is difficult to directly represent their size using diameter. Therefore, in the field of particle size testing, for non-spherical particles, the equivalent particle size (generally referred to as particle size) is usually used to characterize the particle size. The equivalent particle size refers to the diameter (or combination) of a homogeneous sphere (or combination) of a certain diameter when its physical property or behavior is most similar to that of the tested particle. In this application, the D50 particle size refers to the particle size corresponding to a sample where the cumulative volumetric particle size distribution percentage reaches 50%. Its physical meaning is that 50% of the particles are larger than it and 50% are smaller than it. D50 is also called median diameter or median particle size.

[0106] The D50 particle size was determined using a Malvern Mastersizer 3000 particle size analyzer.

[0107] In this application, the D50 particle size of the passivation microsilicon powder is 5-100 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 10-75 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 10-70 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 30-80 μm. In some embodiments, the D50 particle size of the passivation microsilicon powder is 30-50 μm. For example, it can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, etc.

[0108] The specific surface area of ​​the passivated microsilica powder is 0.1-2 m². 2 / g, for example, can be 0.1m 2 / g, 0.2m 2 / g, 0.3m 2 / g, 0.4m 2 / g, 0.5m 2 / g, 0.6m 2 / g, 0.7m 2 / g, 0.8m 2 / g, 0.9m 2 / g, 1m 2 / g, 1.1m 2 / g, 1.2m 2 / g, 1.3m 2 / g, 1.4m 2 / g, 1.5m 2 / g, 1.6m 2 / g, 1.7m 2 / g, 1.8m 2 / g, 1.9m 2 / g、2m 2 / g etc.

[0109] The passivated microsilica powder contains 90-99 wt% silica by mass, for example, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%.

[0110] 98wt%, 99wt%, etc.

[0111] In the preparation of the warm core box, microsilica powder plays two roles. Firstly, it can polymerize with sodium silicate in the liquid component, forming a complex three-dimensional network structure, thereby promoting curing and increasing strength. Secondly, its spherical structure can transform the sliding friction between sand particles into rolling friction, achieving a ball-bearing effect and increasing fluidity. However, the rapid reaction rate of microsilica powder quickly increases the modulus of water glass, forming Si-O-Si bonds and enhancing cohesive strength, thus suppressing the ball-bearing effect of its spherical structure. Passivated microsilica powder, due to its larger particle size, fewer surface hydroxyl groups, and weaker activity, can reduce the reaction rate by up to 35%, thus better leveraging the effects of both microsilica powder and water glass, thereby improving the fluidity of the silica sand mixture.

[0112] In this application, the passivated microsilicon powder is obtained through the following steps and methods:

[0113] Step 1: Add an alkaline treatment solution containing a dispersant to the silica powder, stir, and obtain a mixture;

[0114] Step 2: Add a certain amount of silane coupling agent to the mixture and continue stirring to obtain a mixed slurry;

[0115] Step 3: After filtering and drying the mixed slurry, it is then calcined to obtain the passivated microsilica powder.

[0116] In step one, an alkaline treatment solution containing a dispersant is added to the silica powder, and the mixture is stirred at room temperature to obtain mixture one. Mixture one is then mechanically stirred at high speed at 50-90°C for 1-3 hours to obtain the mixture.

[0117] Specifically, the stirring time at room temperature is 10-30 minutes, for example, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes, 30 minutes, etc. The stirring speed is 1200 rpm-2000 rpm, for example, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, 2000 rpm.

[0118] In this article, room temperature refers to any temperature between 15℃ and 30℃, such as 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc.

[0119] The mixing temperature of the mixture during high-speed mechanical stirring can be any temperature between 50℃ and 90℃, for example, 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃, 90℃, etc. The stirring time can be 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, 3h, etc.

[0120] The stirring rate during the high-speed mechanical stirring process is 1200rpm-2000rpm, for example, 1200rpm, 1400rpm, 1600rpm, 1800rpm, 2000rpm.

[0121] Specifically, the amount of alkaline treatment solution added is 30-60 times the weight of the silica powder. When the weight of the silica powder is m, the amount of alkaline treatment solution added can be any value between 30m and 60m, such as 30m, 32m, 34m, 36m, 38m, 40m, 42m, 44m, 46m, 48m, 50m, 52m, 54m, 56m, 58m, 60m, etc.

[0122] The solute in the alkaline treatment solution is one of sodium carbonate, sodium bicarbonate, potassium carbonate, and ammonium carbonate. The amount of solute added is 5-10% of the alkaline treatment solution, for example, 5%, 6%, 7%, 8%, 9%, 10%, etc. When the mass of the alkaline treatment solution is n, the amount of solute added is any value between 0.05n and 0.1n, for example, 0.05n, 0.06n, 0.07n, 0.08n, 0.09n, 0.1n, etc.

[0123] The dispersant is selected from one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

[0124] The amount of dispersant added is 1-3% of the mass of the alkaline treatment solution, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, etc. When the mass of the alkaline treatment solution is n, the amount of dispersant added is 0.01n, 0.015n, 0.02n, 0.025n, 0.03n, etc.

[0125] In step two, a silane coupling agent is added to the mixture, and stirring continues for 1-3 hours at a stirring speed of 1200 rpm-2000 rpm, for example, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, or 2000 rpm. This yields a mixed slurry.

[0126] The silane coupling agent is selected from one of dimethyldiethoxysilane, trimethylethoxysilane, methyltriethoxysilane, and vinyltriethoxysilane.

[0127] The amount of the silane coupling agent added is 2-5% of the mass of the microsilica powder, preferably 2-3%, for example, it can be 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5%, etc.

[0128] In step three, the roasting temperature is 200-800℃, preferably 500-800℃, and the roasting time is 1-3h.

[0129] Specifically, the roasting temperature can be 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, etc.

[0130] The roasting time can be 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, 3h, etc.

[0131] This application also provides a method for preparing the aforementioned adhesive, comprising the following steps:

[0132] Preparation of Component A: Component A is prepared according to the following formula: sodium silicate 25-40 wt%, potassium hydroxide 0.5-2 wt%, sodium aluminate 0.5-2 wt%, silica sol 2-10 wt%, and the balance being deionized water.

[0133] Preparation of Component B: Component B is prepared according to the following formula: 20-75 wt% passivated microsilica powder, 5-10 wt% graphite powder, 5-20 wt% zircon powder, 5-25 wt% mullite particles and 1-10 wt% lignin sulfonate.

[0134] Specifically, the passivated microsilicon powder is obtained through the following steps and methods:

[0135] Step 1: Add an alkaline treatment solution containing a dispersant to the silica powder, stir, and obtain a mixture;

[0136] Step 2: Add a certain amount of silane coupling agent to the mixture and continue stirring to obtain a mixed slurry;

[0137] Step 3: After filtering and drying the mixed slurry, it is then calcined to obtain the passivated microsilica powder.

[0138] In step one, an alkaline treatment solution containing a dispersant is added to the silica powder, and the mixture is stirred at room temperature to obtain mixture one. Mixture one is then mechanically stirred at high speed at 50-90°C for 1-3 hours to obtain the mixture.

[0139] Specifically, the stirring time at room temperature is 10-30 minutes, for example, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes, 30 minutes, etc. The stirring speed is 1200 rpm-2000 rpm, for example, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, 2000 rpm.

[0140] In this article, room temperature refers to any temperature between 15℃ and 30℃, such as 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc.

[0141] The mixing temperature of the mixture during high-speed mechanical stirring can be any temperature between 50℃ and 90℃, for example, 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃, 90℃, etc. The stirring time can be 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, 3h, etc.

[0142] The stirring rate during the high-speed mechanical stirring process is 1200rpm-2000rpm, for example, 1200rpm, 1400rpm, 1600rpm, 1800rpm, 2000rpm.

[0143] Specifically, the amount of alkaline treatment solution added is 30-60 times the weight of the silica powder. When the weight of the silica powder is m, the amount of alkaline treatment solution added can be any value between 30m and 60m, such as 30m, 32m, 34m, 36m, 38m, 40m, 42m, 44m, 46m, 48m, 50m, 52m, 54m, 56m, 58m, 60m, etc.

[0144] The solute in the alkaline treatment solution is one of sodium carbonate, sodium bicarbonate, potassium carbonate, and ammonium carbonate. The amount of solute added is 5-10% of the alkaline treatment solution, for example, 5%, 6%, 7%, 8%, 9%, 10%, etc. When the mass of the alkaline treatment solution is n, the amount of solute added is any value between 0.05n and 0.1n, for example, 0.05n, 0.06n, 0.07n, 0.08n, 0.09n, 0.1n, etc.

[0145] The dispersant is selected from one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

[0146] The amount of dispersant added is 1-3% of the mass of the alkaline treatment solution, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9wt%, 3wt%, etc. When the mass of the alkaline treatment solution is n, the amount of dispersant added is 0.01n, 0.015n, 0.02n, 0.025n, 0.03n, etc.

[0147] In step two, a silane coupling agent is added to the mixture, and stirring is continued for 1-3 hours at a stirring speed of 1200 rpm-2000 rpm, for example, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, or 2000 rpm, to obtain a mixed slurry.

[0148] The silane coupling agent is selected from one of dimethyldiethoxysilane, trimethylethoxysilane, methyltriethoxysilane, and vinyltriethoxysilane.

[0149] The amount of the silane coupling agent added is 2-5% of the mass of the microsilica powder, for example, it can be 2%, 3%, 4%, 5%, etc.

[0150] In step three, the roasting temperature is 200-800℃ and the roasting time is 1-2 hours.

[0151] Specifically, the roasting temperature can be 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, etc.

[0152] The roasting time can be 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, etc.

[0153] The binder described in this application, when used in sand mold preparation, can effectively improve the fluidity of the mixture of silica sand and binder by component B. This improved fluidity enhances the stability and compactness of the sand mold surface, improving the core-making effect for complex sand cores; it also increases the surface finish and dimensional accuracy of castings, reducing inclusions, porosity, and sand holes, thereby improving casting production efficiency and the economic benefits for foundry manufacturers.

[0154] The spherical structure of component B of the binder in this application enables a ball-bearing effect, transforming the sliding friction between sand grains into rolling friction between sand grains and spherical particles. This reduces solid friction and lowers the viscosity and frictional resistance of the binder-silica sand mixture, effectively improving its flowability. In hammer impact flowability tests, the flowability value is approximately 50% higher compared to similar binders.

[0155] Example

[0156] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0157] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0158] Example 1

[0159] The preparation method of the highly fluid inorganic temperature core box in this embodiment includes the following steps:

[0160] The amount of liquid component A added is 1.6% of the weight of silica sand; the amount of powder component B added is 0.8% of the weight of silica sand. 100 parts by weight of silica sand are placed in a sand mixer, and a certain proportion of the liquid and powder components are added. The mixture is stirred for 3 minutes, and then the mixed molding sand is placed into the core shooter's sand-shooting hopper to prepare for core making. The core-making parameters are: core box temperature 150℃, hot air temperature 200℃, blowing time 60s, and sand-shooting pressure 0.5MPa.

[0161] Liquid component A comprises the following ingredients by mass percentage: sodium silicate 35 wt%, potassium hydroxide 1 wt%, sodium aluminate 1 wt%, silica sol 10 wt%, and deionized water 53 wt%. Powder component B comprises the following ingredients by mass percentage: passivated microsilica powder 50 wt%, zircon powder 15 wt%, mullite particles 10 wt%, sodium lignosulfonate 5 wt%, and graphite powder as the balance.

[0162] The preparation process of passivated silica powder in component B is as follows:

[0163] (1) Add 30 units of alkaline treatment solution to 1 unit weight of silica powder. The alkaline treatment solution is a mixed solution of 5% sodium carbonate and 1% polyethylene glycol 200.

[0164] (2) The mixture was mechanically stirred at room temperature for 10 min, and then stirred at high speed at 60°C for 2 h.

[0165] (3) Then add 3% of dimethyldiethoxysilane equivalent to the weight of the silica powder and continue stirring for 2 hours;

[0166] (4) After filtering and drying the mixed slurry, it is calcined at 500℃ for 3 hours to obtain the dry powder, which is the passivated microsilica powder.

[0167] The mullite particles are spherical alumina particles with a D50 particle size of 50 μm and an alumina content of 65%. The passivated microsilica powder has a D50 particle size of 50 μm and a specific surface area of ​​0.78 m². 2 / g. The passivated microsilica powder contains 97% silicon dioxide, the graphite powder has a D50 particle size of 80μm, and the zircon powder has a D50 particle size of 50μm.

[0168] The parameters of the inorganic temperature core box in this embodiment are shown in Table 1.

[0169] The difference between Examples 2-4 and Comparative Examples 1-2 and Example 1 is that the content of passivating microsilica powder is different, while other parameters are the same. The specific parameters are shown in Table 1.

[0170] The difference between Examples 5 and 6 and Example 1 is that the size of the passivation microsilica powder is different, while other parameters are the same. Specific parameters are shown in Table 1.

[0171] The difference between Examples 7-8 and Comparative Examples 3-4 and Example 1 is that the content of sodium lignosulfonate is different, while other parameters are the same. The specific parameters are shown in Table 1.

[0172] The difference between Examples 9-12 and Example 1 is that the sintering temperature during the preparation of passivated microsilica powder is different, while other parameters are the same. Specific parameters are shown in Table 1.

[0173] The difference between Examples 13-17 and Example 1 is that the mass ratio of component A to component B is different, while all other parameters are the same. Specific parameters are shown in Table 1.

[0174] The difference between Comparative Example 5 and Example 1 is that there is only component A and no component B, while all other parameters are the same. The specific parameters are shown in Table 1.

[0175] The difference between Comparative Example 6 and Example 1 is that the microsilica powder is not passivated, but all other parameters are the same. The specific parameters are shown in Table 1.

[0176] The flowability test was conducted using the hammer impact test method.

[0177] Step (1) Weigh 1 kg of sand and the corresponding binder; pour the materials into the sand mixer and start the mixer to obtain a uniform silica sand / binder mixture.

[0178] Step (2) Weigh 185 grams of sand sample, pour it into a standard sample tube, and place the sample tube under the hammer-type sample preparation machine to scrape off the sand from the side hole.

[0179] Step (3) Impact the sample preparation machine 10 times, and weigh the total weight of the sand squeezed out from the lower hole of the sample cylinder after 10 impacts on a balance.

[0180] The total weight of the sand obtained corresponds to the value of its fluidity. The weight represents the level of fluidity; the greater the weight, the better the fluidity.

[0181] Bending strength is measured using a molding sand strength tester after a bending test block is produced by a core shooter. Collapsibility can be determined by observing the amount of sand core residue remaining in the casting cavity after pouring.

[0182] Table 1 shows the parameters for each embodiment and comparative example.

[0183]

[0184]

[0185] In summary, the binder of this application, when preparing sand molds, can change the sliding friction between sand grains to the rolling friction between sand grains and spherical particles by component B, reducing solid friction and lowering the viscosity and frictional resistance of the binder and silica sand mixture, thereby effectively improving its fluidity (fluidity can reach 9.1g). The improved fluidity can improve the stability and compactness of the sand mold surface, improve the core-making effect of complex sand cores, and increase the surface finish and dimensional accuracy of the casting.

[0186] Although the embodiments of this application have been described above, this application is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of this application, and these are all within the scope of protection of this application.

Claims

1. An inorganic hot box comprising, by weight parts, silica sand 100, a binder 2.2-3.3, wherein the binder comprises a component A and a component B, characterized in that, The B component includes passivated microsilica 20-75wt%, graphite powder 5-10wt%, zirconium powder 5-20wt%, mullite particles 5-25wt% and lignosulfonate 1-10wt%. The mass ratio of the A component to the B component is (1.6-2.2):(0.6-1.1). The particle size of the passivated microsilica is 5-100μm.

2. The inorganic hot-dry rock heat exchanger of claim 1, wherein, The particle size of the passivated microsilica is 30-75μm.

3. The inorganic hot-dry rock heat exchanger of claim 1, wherein, The specific surface area of the passivated microsilica is between 0.1 and 2 m 2 / g.

4. The inorganic hot-dry rock heat exchanger of claim 1, wherein, The content of silicon dioxide in the passivated microsilica is 90-99wt%.

5. The inorganic hot-dry-sack of claim 4, wherein The lignosulfonate is one of sodium lignosulfonate, calcium lignosulfonate and magnesium lignosulfonate; or The mullite particles are artificial sand spherical particles with an alumina content of greater than or equal to 60wt%.

6. The inorganic hot-dry-sack of claim 4, wherein The D50 particle size of the mullite particles is 30-100μm; and / or The D50 particle size of the graphite powder is 30-100μm; and / or The D50 particle size of the zirconium powder is 30-100μm.

7. The inorganic hot-dry rock heat exchanger of claim 1, wherein, The A component includes sodium silicate 25-40wt%, potassium hydroxide 0.5-2wt%, sodium aluminate 0.5-2wt%, silica sol 2-10wt% and the balance is deionized water.

8. A method of producing the inorganic hot box according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: 100 parts by weight of silica sand are put into a sand mixer, a certain proportion of the A component of the binder and the B component of the binder are added, mixed, and the mixed molding sand is put into a sand shooting hopper of a core shooter to make a core.

9. A binder characterized by, The B component includes passivated microsilica 20-75wt%, graphite powder 5-10wt%, zirconium powder 5-20wt%, mullite particles 5-25wt% and lignosulfonate 1-10wt%. The mass ratio of the A component to the B component is (1.6-2.2):(0.6-1.1). The particle size of the passivated microsilica is 5-100μm.

10. The binder of claim 9, wherein, The A component includes sodium silicate 25-40wt%, potassium hydroxide 0.5-2wt%, sodium aluminate 0.5-2wt%, silica sol 2-10wt% and the balance is deionized water.

11. The binder of claim 10, wherein, The lignosulfonate is one of sodium lignosulfonate, calcium lignosulfonate and magnesium lignosulfonate; or The mullite particles are artificial sand spherical particles with an alumina content of greater than or equal to 60wt%.

12. The binder of claim 10, wherein, The D50 particle size of the mullite particles is 30-100μm; and / or The D50 particle size of the graphite powder is 30-100μm; and / or The D50 particle size of the zirconium powder is 30-100μm.

13. The binder of claim 9, wherein, The particle size of the passivated microsilica is 30-75μm.

14. The binder of claim 9, wherein, The specific surface area of the passivated microsilica is between 0.1 and 2 m 2 / g.

15. The binder of claim 9, wherein, The content of silicon dioxide in the passivated microsilica is 90-99wt%.

16. A method of preparing a binder, characterized by, The method comprises the following steps: Preparation of the A component: the A component is prepared according to the formula of sodium silicate 25-40wt%, potassium hydroxide 0.5-2wt%, sodium aluminate 0.5-2wt%, silica sol 2-10wt% and the balance is deionized water; Preparation of the B component: the B component is prepared according to the formula of passivated microsilica 20-75wt%, graphite powder 5-10wt%, zirconium powder 5-20wt%, mullite particles 5-25wt% and lignosulfonate 1-10wt%. The mass ratio of the A component to the B component is (1.6-2.2):(0.6-1.1). The particle size of the passivated microsilica is 5-100 μm.

17. The method of claim 16, wherein, The adhesive prepared is the adhesive of any one of claims 9-15.

Images