Aluminum alloy casting runner pouring material, preparation method and application thereof

Abstract

The application relates to the technical field of refractory materials, and discloses castable for aluminum alloy melting and casting flow channel as well as a preparation method and application thereof; the castable for the aluminum alloy melting and casting flow channel comprises main materials and water; the main materials comprise the following components in percentage by mass: modified fused quartz with different particle sizes 45-53%, chromium-iron slag with different particle sizes 26-32%, corundum micro powder 2-4%, barite micro powder 1-3%, fluorite micro powder 1-3%, forsterite micro powder 2-4%, fly ash 2-4%, aluminate cement 6-10%, and polycarboxylic acid water reducing agent 1%; the water is 4-6% of the mass of the main materials. The surface of the fused quartz is modified, the wettability and encapsulation of the fused quartz and the powder water slurry can be improved, the material uniformity during stirring and shaping of the castable is improved, and the strength of the castable after curing and drying is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refractory materials, in particular to a castable for aluminum alloy melting and casting runner and a preparation method and application thereof. BACKGROUND

[0002] Aluminum alloy has the advantages of light weight, high strength, adjustable composition and performance, etc., and its production and consumption are huge, therefore, high yield of aluminum alloy cannot be achieved without the consumption of supporting auxiliary materials in the production process.

[0003] During the melting and casting process of aluminum alloy, it needs to be transported in various ways between different processing equipment, and short-distance transportation is mainly carried out through a runner. The structure of the runner is composed of an iron shell, a heat preservation layer and a castable layer from the inside to the outside, and the castable layer is the material directly contacted with the aluminum alloy melt.

[0004] Since the melting point of aluminum alloy is not more than 700 DEG C, the refractory degree requirement of the castable for the runner is not high, but the castable is required to have excellent resistance to aluminum alloy melt wetting and erosion and good thermal shock stability. In a number of patents related to aluminum melting and casting castable, the selection of aggregate of the invented castable includes corundum, fused quartz, etc. The Chinese invention patent with publication number CN101734928B “Preparation method of fused quartz refractory castable not wetted by aluminum liquid” mentions that fused quartz has the advantages of low thermal expansion coefficient, good thermal shock resistance, low thermal conductivity, small bulk density, etc. However, practice shows that the surface hydrophilicity of fused quartz in the castable system is poor, and the wetting and wrapping property of aggregate and powder is not strong, which has a negative effect on the overall mechanical property of the castable. In addition, a certain amount of anti-aluminum agent is usually added to the castable to improve the resistance to aluminum liquid wetting and erosion, but these additives usually have high cost.

[0005] Therefore, there is an urgent need for a castable for aluminum alloy melting and casting runner and a preparation method and application thereof to solve the above-mentioned technical problems. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a castable for aluminum alloy melting and casting runner and a preparation method and application thereof. The fused quartz is modified to improve its wetting and wrapping property with the powder slurry, and a large amount of fused quartz and corundum is replaced by chromium iron slag with different particle sizes, so as to maintain high resistance to aluminum liquid wetting while reducing the cost of raw materials. The castable prepared by the present application has the advantages of high strength, good aluminum liquid immersion resistance, long service life, low raw material cost, etc., and is suitable as a matrix material for aluminum alloy melting and casting runner.

[0007] To achieve the above-mentioned purpose, the present application is implemented according to the following technical scheme:

[0008] The application discloses a castable for aluminum alloy melting and casting flow channel, which comprises a main material and water; the main material comprises the following components in percentage by mass: modified fused quartz of different particle sizes 45-53%, chromium-iron slag of different particle sizes 26-32%, corundum micro powder 2-4%, barite micro powder 1-3%, fluorite micro powder 1-3%, forsterite micro powder 2-4%, fly ash 2-4%, aluminate cement 6-10%, and polycarboxylic acid water reducer 1%; and the water is 4-6% of the mass of the main material.

[0009] In the application, the water is added to the main material, and the specific usage amount of the water can be appropriately added or reduced according to the fluidity of the castable, and the specific addition amount is 4-6% of the mass of the main material.

[0010] Preferably, the modified fused quartz is obtained by treating fused quartz with an alkaline solution.

[0011] Specifically, the modified fused quartz is obtained by soaking and corroding fused quartz in an alkaline solution for 24 hours, then washing and drying.

[0012] Preferably, the alkaline solution is a solution with a pH greater than 13.

[0013] Specifically, the alkaline solution is a sodium hydroxide solution or a sodium silicate solution with a pH greater than 13.

[0014] Preferably, the chromium-iron slag is high-carbon chromium-iron dry slag.

[0015] Further, the high-carbon chromium-iron dry slag is high-carbon chromium-iron dry slag treated by iron removal.

[0016] Specifically, the high-carbon chromium-iron dry slag is dry slag generated in the smelting process of high-carbon chromium-iron, and the free iron alloy content of the high-carbon chromium-iron dry slag treated by iron removal is not higher than 0.8%, and the softening temperature is not lower than 1300 DEG C.

[0017] Preferably, the modified fused quartz of different particle sizes comprises the following components in percentage by mass based on the mass of the main material: modified fused quartz with a particle size greater than 5 mm and less than or equal to 8 mm 18-22%, modified fused quartz with a particle size greater than 3 mm and less than or equal to 5 mm 8-12%, modified fused quartz with a particle size greater than 1 mm and less than or equal to 3 mm 8-12%, and modified fused quartz with a particle size greater than 0 mm and less than or equal to 1 mm 7-11%.

[0018] Preferably, the chromium-iron slag of different particle sizes comprises the following mass percentages of each component based on the mass of the main material: 8-12% of chromium-iron slag with a particle size greater than 3mm and less than or equal to 5mm, 8-12% of chromium-iron slag with a particle size greater than 1mm and less than or equal to 3mm, and 7-11% of chromium-iron slag with a particle size greater than 0mm and less than or equal to 1mm.

[0019] The particle size grading of the chromium-iron slag is to achieve close packing and reduce the porosity of the castable; the proportion of the chromium-iron slag is 26-32%, which is to maximize the utilization of the chromium-iron slag while meeting the use requirements, so as to improve the corrosion resistance and recycle solid waste, but the proportion of the chromium-iron slag higher than 32% will introduce excessive Fe and alkali metal impurities, which is not conducive to the high-temperature performance of the castable.

[0020] Preferably, the particle size of the corundum powder, the barite powder, the fluorite powder and the forsterite powder is greater than 0um and less than or equal to 45um.

[0021] Preferably, the median particle size D50 of the fly ash is 4-8um.

[0022] A preparation method of an aluminum alloy melting and casting runner castable, comprising the following steps: uniformly mixing a main material and then adding water, and uniformly mixing to obtain a castable.

[0023] Application of the aluminum alloy melting and casting runner castable in an aluminum alloy melting and casting runner.

[0024] Specifically, the preparation method of the aluminum alloy melting and casting runner comprises the following steps: fully dry mixing the main material, then wet mixing by adding water; vibrating and forming the wet-mixed material into a runner mold, curing in an environment of 10-40 DEG C for 24h, then demolding and placing in a drying kiln for drying, the maximum temperature of the drying is 120 DEG C, to obtain an aluminum alloy melting and casting runner blank; firing the aluminum alloy melting and casting runner blank in a shuttle kiln, the firing temperature is 1200 DEG C, the holding time is 3h, to obtain an aluminum alloy melting and casting runner finished product.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] (1) The surface of the fused quartz is modified, which can improve the wettability and encapsulation of the fused quartz and the powder water slurry, and is beneficial to improving the material uniformity during stirring and forming of the castable, and compared with the castable prepared by using unmodified fused quartz, the strength of the castable prepared by using modified fused quartz is improved by about 10% after curing and drying;

[0027] (2) The chromium-iron slag of different particle sizes is used to replace part of the fused quartz and corundum, which realizes the recycling of solid waste while maintaining high aluminum liquid wetting resistance, and can reduce the cost of raw materials;

[0028] (3) The introduced chromium iron slag, barite micro-powder and fluorite micro-powder can ensure that the castable has good aluminum liquid wetting and corrosion resistance. DETAILED DESCRIPTION

[0029] The application will be further described in the following specific examples. The illustrative examples of the application and the explanations used herein are intended to explain the application but not to limit the application.

[0030] All raw materials of the application are not particularly limited in source, and are purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0031] In the following examples, the particle size of the corundum micro-powder, barite micro-powder, fluorite micro-powder and forsterite micro-powder is greater than 0 μm and less than or equal to 45 μm. The median particle size D50 of the fly ash is 4-8 μm.

[0032] The modified fused quartz in the following examples is prepared according to the following method: different particle sizes of fused quartz are immersed in an alkaline solution for 24 h, then washed with clean water and dried to obtain modified fused quartz of different particle sizes. During the immersion process, the fused quartz is mixed with the alkaline solution according to a mass ratio of 1:2 and stirred. The alkaline solution is a sodium hydroxide solution with a pH greater than 13.

[0033] The chromium iron slag in the following examples is high-carbon chromium iron dry slag after iron removal treatment, and the free iron alloy content is not higher than 0.8%, and the softening temperature is not lower than 1300℃.

[0034] Example 1:

[0035] An aluminum alloy casting runner castable is composed of the following mass fractions of raw materials: 45% of modified fused quartz of different particle sizes, 32% of chromium iron slag of different particle sizes, 3% of corundum micro-powder, 3% of barite micro-powder, 2% of fluorite micro-powder, 3% of forsterite micro-powder, 3% of fly ash, 8% of aluminate cement, 1% of polycarboxylic acid water reducer, and 5.2% of water (additional).

[0036] Based on the mass of the main material, the 45% of modified fused quartz of different particle sizes includes the following mass percentages of each component: 19% of modified fused quartz with a particle size greater than 5 mm and less than or equal to 8 mm, 9% of modified fused quartz with a particle size greater than 3 mm and less than or equal to 5 mm, 9% of modified fused quartz with a particle size greater than 1 mm and less than or equal to 3 mm, and 8% of modified fused quartz with a particle size greater than 0 mm and less than or equal to 1 mm.

[0037] The different particle size chromium-iron slag with a proportion of 32% includes the following components in percentage by mass: chromium-iron slag with a particle size greater than 3mm and less than or equal to 5mm 11%, chromium-iron slag with a particle size greater than 1mm and less than or equal to 3mm 11%, and chromium-iron slag with a particle size greater than 0mm and less than or equal to 1mm 10%.

[0038] The preparation method of the aluminum alloy casting runner includes the following steps: the modified fused quartz of different particle sizes, the chromium-iron slag of different particle sizes, corundum powder, barite powder, fluorite powder, forsterite powder, fly ash, aluminate cement and polycarboxylic acid water reducing agent are fully dry mixed, and then water is added for wet mixing; the wet-mixed material is poured into a runner mold for vibration forming, cured in an environment of 10℃ for 24h, then demolded and placed in a drying kiln for drying, and the drying temperature is 80℃; an aluminum alloy casting runner body is obtained; the aluminum alloy casting runner body is calcined at 1200℃ for 3h to obtain an aluminum alloy casting runner.

[0039] Example 2:

[0040] An aluminum alloy casting runner castable is composed of the following mass fractions of raw materials: modified fused quartz of different particle sizes 53%, chromium-iron slag of different particle sizes 26%, corundum powder 2%, barite powder 3%, fluorite powder 2%, forsterite powder 2%, fly ash 4%, aluminate cement 7%, polycarboxylic acid water reducing agent 1%, and water 4.6% (additional).

[0041] The modified fused quartz of different particle sizes with a proportion of 53% includes the following components in percentage by mass: modified fused quartz with a particle size greater than 5mm and less than or equal to 8mm 22%, modified fused quartz with a particle size greater than 3mm and less than or equal to 5mm 11%, modified fused quartz with a particle size greater than 1mm and less than or equal to 3mm 11%, and modified fused quartz with a particle size greater than 0mm and less than or equal to 1mm 9%.

[0042] The different particle size chromium-iron slag with a proportion of 26% includes the following components in percentage by mass: chromium-iron slag with a particle size greater than 3mm and less than or equal to 5mm 10%, chromium-iron slag with a particle size greater than 1mm and less than or equal to 3mm 8%, and chromium-iron slag with a particle size greater than 0mm and less than or equal to 1mm 8%.

[0043] The preparation method of the aluminum alloy melting casting runner comprises the following steps: the modified fused quartz of different particle sizes, the chromium-iron slag of different particle sizes, corundum powder, barite powder, fluorite powder, forsterite powder, fly ash, aluminate cement and polycarboxylic acid water reducing agent are fully dry mixed, and then water is added for wet mixing; the wet mixed material is poured into a runner mold for vibration forming, cured in an environment of 40℃ for 24h, then demolded and placed in a drying kiln for drying, and the drying temperature is 105℃. An aluminum alloy melting casting runner blank is obtained; the aluminum alloy melting casting runner blank is calcined at 1200℃ for 3h to obtain an aluminum alloy melting casting runner.

[0044] Example 3:

[0045] A castable for an aluminum alloy melting casting runner is composed of the following mass fractions of raw materials: modified fused quartz of different particle sizes 45%, chromium-iron slag of different particle sizes 26%, corundum powder 4%, barite powder 3%, fluorite powder 3%, forsterite powder 4%, fly ash 4%, aluminate cement 10%, polycarboxylic acid water reducing agent 1%, and water 6% (additional).

[0046] Based on the mass of the main material, the modified fused quartz of different particle sizes with a proportion of 45% comprises the following mass percentages of components: modified fused quartz with a particle size greater than 5mm and less than or equal to 8mm 22%, modified fused quartz with a particle size greater than 3mm and less than or equal to 5mm 8%, modified fused quartz with a particle size greater than 1mm and less than or equal to 3mm 8%, and modified fused quartz with a particle size greater than 0mm and less than or equal to 1mm 7%.

[0047] Based on the mass of the main material, the chromium-iron slag of different particle sizes with a proportion of 26% comprises the following mass percentages of components: chromium-iron slag with a particle size greater than 3mm and less than or equal to 5mm 8%, chromium-iron slag with a particle size greater than 1mm and less than or equal to 3mm 8%, and chromium-iron slag with a particle size greater than 0mm and less than or equal to 1mm 10%.

[0048] The preparation method of the aluminum alloy melting casting runner comprises the following steps: the modified fused quartz of different particle sizes, the chromium-iron slag of different particle sizes, corundum powder, barite powder, fluorite powder, forsterite powder, fly ash, aluminate cement and polycarboxylic acid water reducing agent are fully dry mixed, and then water is added for wet mixing; the wet mixed material is poured into a runner mold for vibration forming, cured in an environment of 20℃ for 24h, then demolded and placed in a drying kiln for drying, and the drying temperature is 90℃. An aluminum alloy melting casting runner blank is obtained; the aluminum alloy melting casting runner blank is calcined at 1200℃ for 3h to obtain an aluminum alloy melting casting runner.

[0049] Example 4:

[0050] An aluminum alloy casting runner pouring material is prepared from the following raw materials by mass fraction: modified fused quartz of different particle sizes 49%, chromium-iron slag of different particle sizes 29%, corundum micro powder 3%, barite micro powder 2%, fluorite micro powder 2%, forsterite micro powder 3%, fly ash 3%, aluminate cement 8%, polycarboxylic acid water reducer 1%, and water 5% (added).

[0051] The modified fused quartz of different particle sizes, which accounts for 49% of the mass of the main material, includes the following components by mass percentage: modified fused quartz with a particle size greater than 5 mm and less than or equal to 8 mm 18%, modified fused quartz with a particle size greater than 3 mm and less than or equal to 5 mm 11%, modified fused quartz with a particle size greater than 1 mm and less than or equal to 3 mm 11%, and modified fused quartz with a particle size greater than 0 mm and less than or equal to 1 mm 9%.

[0052] The chromium-iron slag of different particle sizes, which accounts for 29% of the mass of the main material, includes the following components by mass percentage: chromium-iron slag with a particle size greater than 3 mm and less than or equal to 5 mm 10%, chromium-iron slag with a particle size greater than 1 mm and less than or equal to 3 mm 10%, and chromium-iron slag with a particle size greater than 0 mm and less than or equal to 1 mm 9%.

[0053] The preparation method of the aluminum alloy casting runner includes the following steps: the modified fused quartz of different particle sizes, the chromium-iron slag of different particle sizes, the corundum micro powder, the barite micro powder, the fluorite micro powder, the forsterite micro powder, the fly ash, the aluminate cement, and the polycarboxylic acid water reducer are fully dry-mixed, and then water is added for wet mixing; the wet-mixed material is poured into a runner mold for vibration forming, cured in an environment at 30 DEG C for 24 h, then demolded and placed in a drying kiln for drying, and the drying temperature is 80 DEG C. An aluminum alloy casting runner blank is obtained; the aluminum alloy casting runner blank is calcined at 1200 DEG C for 3 h to obtain an aluminum alloy casting runner.

[0054] The aluminum alloy casting runner blank and the finished aluminum alloy casting runner obtained in Examples 1 to 4 are detected to obtain the following data.

[0055]

[0056] In addition, the pouring material prepared in Examples 1 to 4 is made into a crucible, and 3005 aluminum alloy is filled in the crucible to perform a static slag resistance test. After being kept at 800 DEG C for 24 h, the aluminum liquid has no obvious erosion on the crucible material.

[0057] From the data in the above table, it can be seen that the pouring material prepared by the present application can meet the use requirements of the aluminum alloy casting runner.

[0058] The technical solutions of the present application are not limited to the above specific embodiments, and any technical variations made according to the technical solutions of the present application fall within the protection scope of the present application.

Claims

1. A casting refractory for aluminum alloy casting runners, characterized in that: It includes the main material and water; the main material includes the following components by mass percentage: 45-53% modified fused silica of different particle sizes, 26-32% chromium slag of different particle sizes, 2-4% corundum powder, 1-3% barite powder, 1-3% fluorite powder, 2-4% magnesium olivine powder, 2-4% fly ash, 6-10% aluminate cement, and 1% polycarboxylate superplasticizer; Water constitutes 4-6% of the main ingredient's mass. The modified fused silica is obtained by treating fused silica with an alkaline solution; The alkaline solution is a solution with a pH greater than 13; The ferrochrome slag is high-carbon ferrochrome dry slag.

2. The casting refractory for aluminum alloy casting runners according to claim 1, characterized in that: Based on the mass of the main material, modified fused silica of different particle sizes includes the following components by mass percentage: 18-22% modified fused silica with a particle size greater than 5 mm and less than or equal to 8 mm, 8-12% modified fused silica with a particle size greater than 3 mm and less than or equal to 5 mm, 8-12% modified fused silica with a particle size greater than 1 mm and less than or equal to 3 mm, and 7-11% modified fused silica with a particle size greater than 0 mm and less than or equal to 1 mm.

3. The casting refractory for aluminum alloy casting runners according to claim 1, characterized in that: Based on the quality of the main material, the ferrochrome slag of different particle sizes includes the following components in the following mass percentages: ferrochrome slag with a particle size greater than 3 mm and less than or equal to 5 mm 8-12%, ferrochrome slag with a particle size greater than 1 mm and less than or equal to 3 mm 8-12%, and ferrochrome slag with a particle size greater than 0 mm and less than or equal to 1 mm 7-11%.

4. The casting refractory for aluminum alloy casting runners according to claim 1, characterized in that: The particle sizes of the corundum micro powder, barite micro powder, fluorite micro powder, and forsterite micro powder are all greater than 0 μm and less than or equal to 45 μm.

5. The casting refractory for aluminum alloy casting runners according to claim 1, characterized in that: The median particle size D50 of the fly ash is 4-8 μm.

6. A method for preparing a casting refractory for aluminum alloy casting runners according to any one of claims 1-5, characterized in that, The process includes the following steps: after mixing the main materials evenly, add water and mix evenly to obtain the casting refractory.

7. The application of the castable refractory for aluminum alloy casting troughs as described in any one of claims 1-5 in aluminum alloy casting troughs.

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