A surface layer powder for precision casting and preparation method thereof

Abstract

The present invention relates to the field of precision casting technology, and in particular, to a surface layer powder for precision casting and a preparation method thereof. A surface layer powder for precision casting is prepared from the following raw materials in parts by mass: 50-65 parts of bauxite clinker, 5-10 parts of andalusite, 5-10 parts of clay, 1.5-5 parts of white corundum and 0.5-20 parts of functional additives; the functional additives include the following components in percentage by mass: 40%-60% zirconium oxide, 10%-15% aluminum oxide, 5%-10% magnesium oxide and 25%-35% silicon dioxide. The surface layer powder for precision casting obtained by the coordinated cooperation of various raw material components such as andalusite and white corundum has higher refractoriness, low impurity content, good disintegration and stable quality.

Description

Technical Field

[0001] The present invention relates to the technical field of precision casting, and in particular to a surface layer powder for precision casting and a preparation method thereof. Background Art

[0002] The main process of zircon powder currently sold on the market is to obtain zircon sand concentrate after elimination, re-selection, magnetic separation and electrostatic separation of the original ore, and then grind the zircon sand concentrate into micron-sized powder. These powders will be used for the thick wall of large steel castings and the surface layer of various alloy steel castings. As a surface layer material, it has the function of refining grains and is a good shell material. It is often used to prepare surface layer materials. Given the current high price of zircon powder, it is crucial to develop an alternative material that is both low-cost and highly refractory.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] One object of the present invention is to provide a surface layer powder for precision casting, through the coordinated cooperation of various raw material components such as andalusite and white corundum, the obtained surface layer powder for precision casting has higher refractoriness, good disintegration and stable quality.

[0005] Another object of the present invention is to provide a method for preparing surface layer powder for dense casting, which is simple and easy to implement.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0007] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0008] 50-65 parts of bauxite clinker, 5-10 parts of andalusite, 5-10 parts of clay, 1.5-5 parts of white corundum and 0.5-20 parts of functional additives;

[0009] The functional additive comprises the following components in percentage by mass: 40% to 60% zirconium oxide, 10% to 15% aluminum oxide, 5% to 10% magnesium oxide and 25% to 35% silicon dioxide.

[0010] In one embodiment, the surface layer powder for precision casting comprises the following components in parts by weight:

[0011] 60-65 parts of bauxite clinker, 6-8 parts of andalusite, 6-9 parts of clay, 3.5-4.5 parts of white corundum and 7-15 parts of functional additives;

[0012] The functional additive comprises the following components in percentage by mass: 45% to 55% zirconium oxide, 12% to 14% aluminum oxide, 6% to 8% magnesium oxide and 27% to 33% silicon dioxide.

[0013] In one embodiment, the mass ratio of the white corundum to the andalusite is 1:(1.5-4).

[0014] In one embodiment, the particle size of the surface layer powder for precision casting is 36 to 90 μm.

[0015] In one embodiment, in the andalusite, the mass content of aluminum oxide is 58% to 63.5%, the mass content of SiO2 is 36% to 41%, and the mass content of Fe2O3 is 0.5% to 1%.

[0016] In one embodiment, in the white corundum, the mass content of aluminum oxide is 98% to 99%, and the mass content of SiO2 is 0 to 1%.

[0017] In one embodiment, in the bauxite, the mass content of aluminum oxide is 70% to 75%, the mass content of SiO2 is 5% to 10%, the mass content of Fe2O3 is 0.3% to 0.8%, and the mass content of TiO2 is 2% to 3%.

[0018] In one embodiment, in the clay, the mass content of silicon dioxide is 40% to 50%, the mass content of MgO is 1% to 2%, and the mass content of aluminum oxide is 35% to 45%.

[0019] In one embodiment, the particle sizes of the bauxite clinker, andalusite, clay, white corundum and functional additives are 10 to 50 μm, respectively.

[0020] In one embodiment, the particle size of the bauxite clinker is 20-30 μm, the particle size of the andalusite is 25-35 μm, the particle size of the clay is 10-25 μm, the particle size of the white corundum is 30-45 μm, and the particle size of the functional additive is 25-45 μm.

[0021] The method for preparing the surface layer powder for precision casting comprises the following steps:

[0022] The mixture of bauxite clinker, andalusite, clay, white corundum and functional additives is sequentially subjected to primary homogenization treatment, moisture wetting treatment, covering treatment, secondary homogenization treatment, drying treatment, calcination treatment and grinding treatment.

[0023] In one embodiment, the homogenization treatment lasts for 2 to 4 hours.

[0024] In one embodiment, the secondary homogenization treatment is performed for 1.5 to 2.5 hours.

[0025] In one embodiment, the mass content of water in the mixture after the water wetting treatment is 5% to 20%.

[0026] In one embodiment, the covering treatment time is 6 to 12 hours.

[0027] In one embodiment, the drying temperature is 50-100° C., and the drying time is 1-2 hours.

[0028] In one embodiment, the calcination temperature is 1500-1700° C., and the calcination time is 16-24 hours.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention uses the coordinated cooperation of various raw material components such as andalusite and white corundum to obtain a surface layer powder for precision casting with higher refractoriness, lower impurity content, better disintegration and stable quality.

[0031] (2) Another object of the present invention is to provide a method for preparing a surface layer powder for dense casting, which does not produce any tailings or waste slag and is environmentally friendly; the cost is low; and the particle size distribution of the obtained powder can be adjusted. DETAILED DESCRIPTION

[0032] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0033] According to one aspect of the present invention, the present invention relates to a surface layer powder for precision casting, which is prepared from raw materials including the following parts by mass:

[0034] 50-65 parts of bauxite clinker, 5-10 parts of andalusite, 5-10 parts of clay, 1.5-5 parts of white corundum and 0.5-20 parts of functional additives;

[0035] The functional additive comprises the following components in percentage by mass: 40% to 60% zirconium oxide, 10% to 15% aluminum oxide, 5% to 10% magnesium oxide and 25% to 35% silicon dioxide.

[0036] The present invention obtains a surface layer powder for precision casting with higher refractoriness, good disintegration and stable quality through the coordinated cooperation of various raw material components such as andalusite and white corundum. White corundum has a lower iron content than brown corundum, and the surface layer powder requires the lower the iron content, the better; the further the content of zirconium oxide is, the more conducive it is to cooperate with andalusite, white corundum and the like to improve the refractoriness of the surface layer powder.

[0037] All raw materials of the present invention are sorted, impurity-free and purified in advance to reduce the impurity content and ensure that no chemical reaction occurs with the casting during use. The high refractoriness of the product is ensured by the combination of an appropriate amount of functional additives.

[0038] In one embodiment, the bauxite clinker includes, but is not limited to, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64 or 65 parts by mass.

[0039] In one embodiment, andalusite includes, but is not limited to, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts or 9.5 parts by mass.

[0040] In one embodiment, the clay includes, but is not limited to, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts or 9.5 parts by weight.

[0041] In one embodiment, the white corundum includes, but is not limited to, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5 parts by mass.

[0042] In one embodiment, the functional additives include, but are not limited to, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, and 19.5 parts by mass.

[0043] In one embodiment, the surface layer powder for precision casting comprises the following components in parts by weight:

[0044] 60-65 parts of bauxite clinker, 6-8 parts of andalusite, 6-9 parts of clay, 3.5-4.5 parts of white corundum and 7-15 parts of functional additives;

[0045] The functional additive comprises the following components in percentage by mass: 45% to 55% zirconium oxide, 12% to 14% aluminum oxide, 6% to 8% magnesium oxide and 27% to 33% silicon dioxide.

[0046] The raw material components within the above range can exert a more excellent synergistic effect.

[0047] In one embodiment, the mass ratio of the white corundum to the andalusite is 1:(1.5-4).

[0048] In one embodiment, the particle size of the surface layer powder for precision casting is 36 to 90 μm. In one embodiment, the particle size of the surface layer powder for precision casting includes but is not limited to 40 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm or 90 μm.

[0049] In one embodiment, the mass content of aluminum oxide in the andalusite is 58% to 63.5%, the mass content of SiO2 is 36% to 41%, and the mass content of Fe2O3 is 0.5% to 1%. In one embodiment, the mass content of aluminum oxide in the andalusite can be 58%, 59%, 60%, 61%, 62% or 63%, the mass content of SiO2 includes but is not limited to 37%, 38%, 39%, 40% or 41%, and the mass content of Fe2O3 includes but is not limited to 0.6%, 0.7%, 0.8%, 0.9%.

[0050] In one embodiment, the mass content of aluminum oxide in the white corundum is 98% to 99%, and the mass content of SiO2 is 0 to 1%. In one embodiment, the mass content of aluminum oxide in the white corundum includes but is not limited to 98.5%, and the mass content of SiO2 can be 0.2%, 0.5%, 0.7%, or 0.9%.

[0051] In one embodiment, in the bauxite, the mass content of aluminum oxide is 70% to 75%, the mass content of SiO2 is 5% to 10%, the mass content of Fe2O3 is 0.3% to 0.8%, and the mass content of TiO2 is 2% to 3%. In one embodiment, in the bauxite, the mass content of aluminum oxide includes but is not limited to 71%, 72%, 73%, 74% or 75%, the mass content of SiO2 is but is not limited to 6%, 7%, 8% or 9%, the mass content of Fe2O3 is but is not limited to 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, and the mass content of TiO2 is but is not limited to 2.2%, 2.5%, 2.9%.

[0052] In one embodiment, the mass content of silicon dioxide in the clay is 40% to 50%, the mass content of MgO is 1% to 2%, and the mass content of aluminum oxide is 35% to 45%. In one embodiment, the mass content of silicon dioxide in the clay includes but is not limited to 41%, 43%, 45%, 47%, 50%, the mass content of MgO includes but is not limited to 1.2%, 1.5%, 1.7%, 2%, and the mass content of aluminum oxide includes but is not limited to 37%, 40%, 43% or 45%.

[0053] In one embodiment, the particle sizes of the bauxite clinker, andalusite, clay, white corundum and functional additives are 10 to 50 μm, respectively. In one embodiment, the particle sizes of the bauxite clinker, andalusite, clay, white corundum and functional additives include but are not limited to 11 μm, 12 μm, 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 30 μm, 32 μm, 35 μm, 37 μm, 40 μm, 45 μm, 47 μm and 49 μm.

[0054] In one embodiment, the particle size of the bauxite clinker is 20-30 μm, the particle size of the andalusite is 25-35 μm, the particle size of the clay is 10-25 μm, the particle size of the white corundum is 30-45 μm, and the particle size of the functional additive is 25-45 μm.

[0055] By setting the particle sizes of bauxite clinker, andalusite, clay, white corundum and functional additives within the above-mentioned specific range, the surface layer powder for precision casting obtained by the present invention has more excellent refractoriness, more stable quality and better diffusibility.

[0056] In another aspect, the present invention relates to a method for preparing the surface layer powder for precision casting, comprising the following steps:

[0057] The mixture of bauxite clinker, andalusite, clay, white corundum and functional additives is sequentially subjected to primary homogenization treatment, moisture wetting treatment, covering treatment, secondary homogenization treatment, drying treatment, calcination treatment and grinding treatment.

[0058] The production process of the present invention is simple, without any tailings or waste residues, and is environmentally friendly. There is no cost for processing tailings in the later stage of zircon production, and the overall cost is lower than that of zircon powder. Through the mutual coordination of the above-mentioned specific steps, the particle size distribution and particle size of the obtained powder can be adjusted. Since the slurry dries faster in precision casting, the production efficiency can be improved, and the product quality is stable and improved to a certain extent.

[0059] In one embodiment, the homogenization treatment lasts for 2 to 4 hours.

[0060] In one embodiment, the time of the secondary homogenization treatment is 1.5 to 2.5 hours. In one embodiment, the time of the secondary homogenization treatment includes but is not limited to 2 hours.

[0061] In one embodiment, the mass content of water in the mixture after the water humidification treatment is 5% to 20%, specifically 6%, 7%, 10%, 12%, 15%, 17% or 19%. The use of appropriate water humidification is conducive to the subsequent covering treatment.

[0062] In one embodiment, the covering treatment time is 6 to 12 hours. It can also be 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours. An appropriate covering treatment time is beneficial to improving the refractoriness of the powder.

[0063] In one embodiment, the drying temperature is 50-100°C, and the drying time is 1-2 hours. The drying temperature includes but is not limited to 60°C, 70°C, 80°C, and 90°C. The drying time is 1.2 hours, 1.5 hours, and 1.7 hours.

[0064] In one embodiment, the calcination temperature is 1500-1700°C, and the calcination time is 16-24 hours. The calcination temperature includes but is not limited to 1550°C, 1570°C, 1600°C, 1630°C, 1650°C, and 1670°C.

[0065] The above-mentioned suitable calcination temperature and time can obtain a powder with higher refractoriness.

[0066] The following will further explain with reference to specific embodiments.

[0067] Example 1

[0068] Precision casting surface powder, including the following components in parts by mass:

[0069] 62 parts of bauxite clinker, 7.8 parts of andalusite, 7.5 parts of clay, 3.6 parts of white corundum and 11 parts of functional additives;

[0070] The functional additive comprises the following components in percentage by mass: 50% zirconium oxide, 13% aluminum oxide, 7% magnesium oxide and 30% silicon dioxide.

[0071] The method for preparing the surface layer powder for precision casting comprises:

[0072] Grinding bauxite clinker, andalusite, clay, white corundum and functional additives respectively, and screening to obtain the following particle size ranges: the particle size of the bauxite clinker is 20-30 μm, the particle size of the andalusite is 25-35 μm, the particle size of the clay is 10-25 μm, the particle size of the white corundum is 30-45 μm, and the particle size of the functional additive is 25-45 μm;

[0073] The mixture of the above raw materials is homogenized once for 3 hours; the mixed material after the first homogenization is humidified (sprayed) with the moisture content controlled at 12%; then covered (covered) for 7.5 hours; then homogenized twice for 2 hours, then dried at 85°C for 1.5 hours; then calcined at 1650°C for 18 hours; the irregular particles after cooling are ground into powder, which can be further classified and packaged.

[0074] Example 2

[0075] A surface layer powder for precision casting, comprising 60 parts of bauxite clinker, 8 parts of andalusite, 6 parts of clay, 4.5 parts of white corundum and 7 parts of functional additives; the composition of the functional additives is the same as that of Example 1;

[0076] The preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0077] Example 3

[0078] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0079] 65 parts of bauxite clinker, 6 parts of andalusite, 9 parts of clay, 3.5 parts of white corundum and 15 parts of functional additives; the composition of the functional additives is the same as that of Example 1;

[0080] The preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0081] Example 4

[0082] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0083] 50 parts of bauxite clinker, 5 parts of andalusite, 10 parts of clay, 1.5 parts of white corundum and 0.5 parts of functional additives; the composition of the functional additives is the same as that of Example 1;

[0084] The preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0085] Example 5

[0086] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0087] 62 parts of bauxite clinker, 6.4 parts of andalusite, 7.5 parts of clay, 5 parts of white corundum and 11 parts of functional additives.

[0088] The preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0089] Comparative Example 1

[0090] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0091] 62 parts of bauxite clinker, 7.5 parts of clay, 4 parts of white corundum and 11 parts of functional additives; the composition of the functional additives is the same as that in Example 1; the preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0092] The raw materials of this comparative example do not contain andalusite.

[0093] Comparative Example 2

[0094] A surface layer powder for precision casting, comprising the following components in parts by mass:

[0095] 62 parts of bauxite clinker, 7 parts of andalusite, 7.5 parts of clay, and 4 parts of white corundum; the composition of the functional additive is the same as that in Example 1; the preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0096] The raw materials of this comparative example do not contain any functional additives.

[0097] Comparative Example 3

[0098] A surface layer powder for precision casting, comprising the following components in parts by mass:

[0099] 62 parts of bauxite clinker, 7 parts of andalusite, 7.5 parts of clay and 11 parts of functional additives; the composition of the functional additives is the same as that in Example 1; the preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0100] The raw materials of this comparative example do not contain white corundum.

[0101] Comparative Example 4

[0102] A surface layer powder for precision casting is prepared from the following raw materials in parts by weight:

[0103] 75 parts of bauxite clinker, 2 parts of andalusite, 12 parts of clay, 0.5 parts of white corundum and 0.1 parts of functional additives; the composition of the functional additives is the same as that in Example 1; the preparation method of the surface layer powder for precision casting is the same as that in Example 1.

[0104] The mass fractions of the raw materials in this comparative example are not within the protection scope of the present invention.

[0105] Experimental example

[0106] The surface layer powders for precision casting obtained in the examples and comparative examples were subjected to a refractoriness performance test, and the refractoriness test standard was GB / T 7322-2017. The results are shown in Table 1.

[0107] Table 1 Refractoriness performance test results

[0108]

[0109]

[0110] As shown in Table 1, the surface layer powder for precision casting obtained by the embodiment of the present invention has excellent refractoriness, which can reach 2130° C. through the coordination of various raw material components and the coordination of various specific parameter conditions. As shown in Comparative Examples 1 to 4, if a component is missing or the proportion of each component is not within the protection range, the refractoriness will decrease.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A surface layer powder for precision casting, characterized in that: Prepared from the following raw materials in parts by weight: 60-65 parts of bauxite clinker, 6-8 parts of andalusite, 6-9 parts of clay, 3.5-4.5 parts of white corundum and 7-15 parts of functional additives; The functional additive comprises the following components in percentage by mass: 45% to 55% zirconium oxide, 12% to 14% aluminum oxide, 6% to 8% magnesium oxide and 27% to 33% silicon dioxide; The mass ratio of the white corundum to the andalusite is 1:(1.5-4); The particle size of the surface layer powder for precision casting is 36-90 μm; In the andalusite, the mass content of aluminum oxide is 58% to 63.5%, the mass content of SiO2 is 36% to 41%, and the mass content of Fe2O3 is 0.5% to 1%; In the white corundum, the mass content of aluminum oxide is 98% to 99%, and the mass content of SiO2 is 0 to 1%; The bauxite has a mass content of aluminum oxide of 70% to 75%, a mass content of SiO2 of 5% to 10%, a mass content of Fe2O3 of 0.3% to 0.8%, and a mass content of TiO2 of 2% to 3%; In the clay, the mass content of silicon dioxide is 40% to 50%, the mass content of MgO is 1% to 2%, and the mass content of aluminum oxide is 35% to 45%; The particle sizes of the bauxite clinker, andalusite, clay, white corundum and functional additives are 10-50 μm respectively.

2. The surface layer powder for precision casting according to claim 1, characterized in that: The particle size of the bauxite clinker is 20-30 μm, the particle size of the andalusite is 25-35 μm, the particle size of the clay is 10-25 μm, the particle size of the white corundum is 30-45 μm, and the particle size of the functional additive is 25-45 μm.

3. The method for preparing a surface layer powder for precision casting according to any one of claims 1 to 2, characterized in that: The following steps are involved: The mixture of bauxite clinker, andalusite, clay, white corundum and functional additives is sequentially subjected to primary homogenization treatment, moisture wetting treatment, covering treatment, secondary homogenization treatment, drying treatment, calcination treatment and grinding treatment.

4. The method for preparing the surface layer powder for precision casting according to claim 3, characterized in that: Contains at least one of the following characteristics (1) to (4): (1) The time of the homogenization treatment is 2 to 4 hours; (2) The secondary homogenization treatment time is 1.5 to 2.5 hours; (3) The mass content of water in the mixture after the water humidification treatment is 5% to 20%; (4) The covering treatment time is 6 to 12 hours.

5. The method for preparing the surface layer powder for precision casting according to claim 3 or 4, characterized in that: The temperature of the drying process is 50-100° C., and the time of the drying process is 1-2 hours.

6. The method for preparing the surface layer powder for precision casting according to claim 3 or 4, characterized in that: The temperature of the calcination treatment is 1500-1700° C., and the time of the calcination treatment is 16-24 hours.

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