A foundry sand core coating

Abstract

A kind of foundry sand core coating is used for the preparation of foundry sand core coating.The foundry sand core coating is prepared by fully stirring white clay as binder, calcium bentonite as suspending agent, chalk powder as refractory material, graphite powder and n-octanol as additives, and industrial alcohol as carrier;white clay, calcium bentonite and industrial alcohol are added in a weight ratio of 6-8:2:6, and stirred at a speed of 380 r / min for 40 min to obtain a mixed solution;then, the chalk powder, graphite powder and n-octanol with specific gravities of 0.2%-0.3%, 0.05%-0.1% and 0.02% of calcium bentonite, respectively, are sequentially added to the mixed solution, and stirred at a speed of 380 r / min for 20 min to obtain the foundry sand core coating.The foundry sand core coating of the present application only needs to be sealed and stored, without the need for storage in a specific environment, and can be recycled without the need for re-proportioning and preparation before each subsequent use by stirring at a speed of 400 r / min for 30 min.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of casting technology, in particular to a kind of coating for foundry sand core. BACKGROUND

[0002] The main role of foundry sand core coating is to prevent the surface of casting from producing sand sticking defects, make the grain of casting surface more refined, reduce the roughness of casting surface, etc. The heat-resistant coating of foundry sand core coating can close the large number of pores existing on the surface of the core, can provide a layer of densification, refractoriness and higher thermal chemical stability for foundry sand core, can effectively prevent the penetration or thermal chemical reaction of metal liquid. But the foundry sand core coating used in the industry at present is expensive, most of the sand core coating contains resin, and due to the high cost of resin, the resin in the coating will volatilize and cause the coating to be unable to be recycled, which is not conducive to storage and recycling after opening. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the present application aims to provide a kind of foundry sand core coating, which can meet the needs of casting surface and internal quality, reduce cost and achieve the purpose of recycling.

[0004] To achieve the above-mentioned purpose of the application, the foundry sand core coating is prepared by fully stirring white mud as binder, calcium-based bentonite as suspending agent, chalk powder as refractory material, graphite powder and n-octanol as additives, and industrial alcohol as carrier.

[0005] Further, the white mud and calcium-based bentonite are fully stirred with industrial alcohol after weighing and mixing, and then chalk powder, graphite powder and n-octanol are added for stirring to obtain the foundry sand core coating.

[0006] Further, the weight ratio of the white mud, calcium-based bentonite and industrial alcohol is 6-8:2:6, and the mixture is obtained by stirring at a speed of 380 r / min for 40 min; then the chalk powder, graphite powder and n-octanol are sequentially added to the mixture, wherein the addition ratio of the chalk powder, graphite powder and n-octanol is 0.2%-0.3%, 0.05%-0.1% and 0.02% of the calcium-based bentonite, respectively; and then the mixture is stirred at a speed of 380 r / min for 20 min to obtain the required foundry sand core coating.

[0007] Further, the foundry sand core coating is stirred at a speed of 400 r / min for 30 min before each subsequent use, without the need for re-proportioning and preparation.

[0008] Further, the foundry sand core coating only needs to be sealed and stored, without the need for storage in a specific environment.

[0009] Compared with the prior art, the casting sand core coating prepared by replacing zirconium powder and quartz powder in the traditional casting sand core coating with low-cost white mud and bentonite can be only sealed and stored, does not need to be stored in a specific environment, and can be conveniently used after stirring at a rotating speed of 400 r / min for 30 min before each subsequent use, thereby reducing production cost and being recyclable and beneficial to environmental protection. DETAILED DESCRIPTION

[0010] The casting sand core coating is prepared by taking white mud as a binder, calcium-based bentonite as a suspending agent, chalk powder as a refractory material, graphite powder and n-octanol as additives, and industrial alcohol as a carrier; the mixing liquid is obtained by stirring the white mud, calcium-based bentonite and industrial alcohol at a weight ratio of 6-8:2:6 at a rotating speed of 380 r / min for 40 min; then the chalk powder, graphite powder and n-octanol are sequentially added to the mixing liquid, and the addition ratios of the chalk powder, graphite powder and n-octanol are 0.2%-0.3%, 0.05%-0.1% and 0.02% of the calcium-based bentonite, respectively; and the casting sand core coating is obtained by stirring at a rotating speed of 380 r / min for 20 min.

[0011] Example 1

[0012] The mixing liquid is obtained by stirring the white mud, calcium-based bentonite and industrial alcohol at a weight ratio of 8:2:6 at a rotating speed of 380 r / min for 40 min; then the chalk powder, graphite powder and n-octanol are sequentially added to the mixing liquid, and the addition ratios of the chalk powder, graphite powder and n-octanol are 0.2%, 0.1% and 0.02% of the calcium-based bentonite, respectively; and the casting sand core coating is obtained by stirring at a rotating speed of 380 r / min for 20 min.

[0013] The sand core coating ratio is shown in Table 1.

[0014]

[0015] Example 2

[0016] The mixing liquid is obtained by stirring the white mud, calcium-based bentonite and industrial alcohol at a weight ratio of 7:2:6 at a rotating speed of 380 r / min for 40 min; then the chalk powder, graphite powder and n-octanol are sequentially added to the mixing liquid, and the addition ratios of the chalk powder, graphite powder and n-octanol are 0.3%, 0.1% and 0.02% of the calcium-based bentonite, respectively; and the casting sand core coating is obtained by stirring at a rotating speed of 380 r / min for 20 min.

[0017] The sand core coating ratio is shown in Table 2.

[0018]

[0019] Example 3

[0020] The white mud, calcium bentonite and industrial alcohol are mixed in a weight ratio of 6:2:6, stirred at a speed of 380 r / min for 40 min to obtain a mixed solution, then the chalk powder, graphite powder and n-octanol are added into the mixed solution in sequence, the adding proportion of each is 0.3%, 0.1% and 0.02% of the weight of the calcium bentonite respectively, and then stirred at a speed of 380 r / min for 20 min to obtain the required sand core coating.

[0021] The sand core coating ratio is shown in Table 3:

[0022]

[0023] Example 4

[0024] The white mud, calcium bentonite and industrial alcohol are mixed in a weight ratio of 7:2:6, stirred at a speed of 380 r / min for 40 min to obtain a mixed solution, then the chalk powder, graphite powder and n-octanol are added into the mixed solution in sequence, the adding proportion of each is 0.2%, 0.05% and 0.02% of the weight of the calcium bentonite respectively, and then stirred at a speed of 380 r / min for 20 min to obtain the required sand core coating.

[0025] The sand core coating ratio is shown in Table 4:

[0026]

[0027] Casting tests are respectively conducted on Example 1, Example 2, Example 3 and Example 4, and the coating density, sand core dipping state, appearance of the castings and internal quality of the castings are shown in Table 5:

[0028]

Claims

1. A process for making a foundry sand core coating, characterized by: The casting sand core coating is prepared by fully stirring white mud as a binder, calcium-based bentonite as a suspending agent, chalk powder as a refractory material, graphite powder and n-octanol as additives, and industrial alcohol as a carrier; The white mud and the calcium-based bentonite are fully stirred in industrial alcohol after being weighed and mixed, and then chalk powder, graphite powder and n-octanol are added and stirred to obtain the casting sand core coating; The white mud, the calcium-based bentonite and the industrial alcohol are mixed at a weight ratio of 6-8:2:6, and stirred at a speed of 380 r / min for 40 min to obtain a mixed solution; then the chalk powder, the graphite powder and the n-octanol are sequentially added to the mixed solution, wherein the adding proportion of the chalk powder, the graphite powder and the n-octanol is 0.2%-0.3%, 0.05%-0.1% and 0.02% of the calcium-based bentonite respectively; and then the mixture is stirred at a speed of 380 r / min for 20 min to obtain the required casting sand core coating; The casting sand core coating is stirred at a speed of 400 r / min for 30 min before each subsequent use, and does not need to be re-proportioned and prepared; The casting sand core coating only needs to be sealed and stored, and does not need to be stored in a specific environment.

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