CN110947902A

CN110947902A - Casting 3D printing sand and preparation method thereof

Info

Publication number: CN110947902A
Application number: CN201911278320.2A
Authority: CN
Inventors: 李冰
Original assignee: Qingdao Multivariate New Material Co Ltd
Current assignee: Qingdao Multivariate New Material Co Ltd
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-04-03

Abstract

The invention discloses cast 3D printing sand and a preparation method thereof, wherein the cast 3D printing sand comprises 20-40% of bauxite, 10-15% of alumina powder, 20-35% of kaolin and the balance of inorganic carbon powder in parts by mass. The casting 3d printing sand has high refractoriness, low thermal expansion rate, high sand shape roundness and surface smoothness, can effectively protect printing equipment, simultaneously reduce the using amount of resin binder, improve the using efficiency and yield of the casting 3d printing sand mold, and can be repeatedly used in casting application because the strength and hardness of the artificial sand are higher than those of foreign 3d casting sand, thereby reducing environmental protection hazards and effectively reducing casting cost.

Description

Casting 3D printing sand and preparation method thereof

Technical Field

The invention relates to the field of casting sand, in particular to casting 3D printing sand and a preparation method thereof.

Background

Foundry sand is a granular molding material used to prepare sand molds and core sand in foundry production. Resin is used as a molding sand binder, a core type is printed in 3d, about 3 tons of new molding sand needs to be supplemented every time 1 ton of qualified castings are produced, and therefore the using amount of the casting sand in sand casting production is huge.

With the development of the casting market, the 3d core sand printing process can greatly reduce the development cost of a new product and improve the development efficiency, but the current domestic 3d printing sand is mainly imported by Germany and America, the cost is extremely high, the shape of the domestic silica sand grains is not round enough, the needle of printing equipment is easy to lock, the resin binder is high in usage amount, the imported 3d printing sand is basically silica sand, the thermal ablation and the regeneration loss of the silica sand are huge, the resource waste is caused, the waste sand pollutes the environment and has no recycling value, the Baozhu sand is also used as the raw sand of the 3d printing sand in the market, the Baozhu sand is manufactured by a high-pollution and high-energy-consumption process, high bauxite is melted into liquid through electric arcs, and high-temperature liquid is swept by strong wind to form particles close to spherical shape. The process also determines that whether the Baozhu sand is mined from the ore raw materials at the early stage or prepared from the Baozhu sand, a large amount of pollution which is difficult to treat is generated, so that the manufacturing cost of the Baozhu sand is high, and the casting cost is increased. Therefore, research and development of a 3d printing sand product capable of improving casting efficiency, reducing cost and improving environmental protection regeneration are increasingly becoming the focus of research.

Disclosure of Invention

In order to solve the technical problems, the invention discloses casting 3D printing sand with high refractoriness, high strength, low thermal expansion rate and high repeated utilization rate and a preparation method thereof.

The technical scheme of the invention is as follows: the casting 3D printing sand comprises the following components: bauxite, alumina powder, kaolin and inorganic carbon powder.

Further, the aluminum bauxite-alumina composite material comprises, by mass, 20-40% of bauxite, 10-15% of alumina powder, 20-35% of kaolin and the balance of inorganic carbon powder.

Further, 30% of bauxite, 13% of alumina powder, 30% of kaolin and the balance of inorganic carbon powder.

Further, the preparation method of the casting 3D printing sand comprises the following steps:

(1) respectively taking kaolin and bauxite, crushing the kaolin and the bauxite into raw materials, mixing and homogenizing the raw materials with alumina powder and inorganic carbon powder; (2) grinding the mixed raw materials again for homogenization, and then carrying out sealed isolated fermentation for homogenization; (3) spraying high gravity cluster by water mist for granulation, continuously rotating to increase the strength, screening the prepared granules, and performing surface polishing treatment; (4) and calcining the polished and screened particles in a rotary kiln at high temperature to obtain the finished casting 3d printing sand.

Further, the temperature in the rotary kiln in the step (4) is 1200-1600 ℃, and the high-temperature calcination time is 3 hours.

Further, the application of the casting 3D printing sand in self-hardening sand casting, lost foam casting and cold box molding is included.

The invention comprises bauxite, alumina powder, kaolin and inorganic carbon powder, has simple components, simple and easily obtained raw materials, simple preparation process, low energy consumption, high production efficiency, easy environmental protection treatment of production wastes and effective reduction of cost. The artificial casting 3d printing sand disclosed by the invention has the advantages of high refractoriness, high strength, low thermal expansion rate, high repeated utilization rate, and capability of protecting a printing needle head and improving the compactness of a sand mold due to the advantages of roundness and smoothness, so that the casting requirement can be met, and the casting process cost can be effectively reduced. The invention has potential market value.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a photograph of cast 3D printed sand according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In the description of the embodiments, the terms "disposed," "connected," and the like are to be construed broadly unless otherwise explicitly specified or limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; either directly or through an intervening medium, or through internal communication between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

Example 1

The casting 3D printing sand comprises the following components: bauxite, alumina powder, kaolin and inorganic carbon powder. The aluminum-vanadium-containing composite material comprises, by mass, 20% of bauxite, 10% of alumina powder, 20% of kaolin and the balance of inorganic carbon powder.

(1) respectively taking kaolin and bauxite, crushing the kaolin and the bauxite into raw materials, mixing and homogenizing the raw materials with alumina powder and inorganic carbon powder; (2) grinding the mixed raw materials again for homogenization, and then carrying out sealed isolated fermentation for homogenization; (3) spraying high gravity cluster by water mist for granulation, continuously rotating to increase the strength, screening the prepared granules, and performing surface polishing treatment; (4) and calcining the polished and screened particles at high temperature in a rotary kiln at 1200-1600 ℃ to obtain the finished casting 3d printing sand. The high-temperature calcination time is 3 h.

Example 2

The casting 3D printing sand comprises the following components: bauxite, alumina powder, kaolin and inorganic carbon powder. The aluminum-vanadium-containing composite material comprises, by mass, 30% of bauxite, 13% of alumina powder, 30% of kaolin and the balance of inorganic carbon powder.

Example 3

The casting 3D printing sand comprises the following components: bauxite, alumina powder, kaolin and inorganic carbon powder. The aluminum-vanadium-containing composite material comprises, by mass, 40% of bauxite, 15% of alumina powder, 35% of kaolin and the balance of inorganic carbon powder.

Comparative example 1

Comparative example 1 is U.S. sand from COVIA.

Comparative example 2

Comparative example 2 was german sand from Quarzwerke.

Comparative example 3

Comparative example 3 is a conventional precious pearl sand on the market.

Experimental conditions

(1) Bulk density test and the like

The results of tests on the bulk density, the breakage rate and the refractoriness of examples 1 to 3 and comparative examples 1 to 3 are shown in Table 1.

Table 1 is a table of results of tests for indexes such as bulk density

As can be seen from Table 1, in examples 1 to 3, compared with comparative examples 1 to 3, the crushing rate is low, the refractoriness is high, the refractory material can be used for many times, the number of times of use reaches more than 100, and the casting cost can be effectively reduced.

(2) Strength test

The final product sand consisting of 35% by mass of example 1-3, comparative example 3 and 65% by mass of roasted sand is used for carrying out experiments such as strength and the like, the data detection is the average value of 4 test blocks, the GB/T2684 standard is adopted as the sampling mode, the triethylamine cold core method GB/T5611 is adopted for labeling detection, and the experimental results are shown in Table 2.

Table 2 shows the results of tests for indexes such as strength

As can be seen from Table 2, the instant tensile strength and the 24-hour tensile strength of the product sands containing examples 1 to 3 were significantly higher than those of the product sands containing comparative example 3 among the product sands composed in the same ratio.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization of those skilled in the art; where combinations of features are mutually inconsistent or impractical, such combinations should not be considered as being absent and not within the scope of the claimed invention.

Claims

1. The casting 3D printing sand is characterized by comprising the following components: bauxite, alumina powder, kaolin and inorganic carbon powder.

2. The cast 3D printing sand of claim 1, wherein: the aluminum-vanadium-containing composite material comprises, by mass, 20-40% of bauxite, 10-15% of alumina powder, 20-35% of kaolin and the balance of inorganic carbon powder.

3. The cast 3D printing sand of claim 2, wherein: 30% of bauxite, 13% of alumina powder, 30% of kaolin and the balance of inorganic carbon powder.

4. The method of preparing foundry 3D printing sand as recited in claim 1, comprising the steps of:

(1) respectively taking kaolin and bauxite, crushing the kaolin and the bauxite into raw materials, mixing and homogenizing the raw materials with alumina powder and inorganic carbon powder;

(2) grinding the mixed raw materials again for homogenization, and then carrying out sealed isolated fermentation for homogenization;

(3) spraying high gravity cluster by water mist for granulation, continuously rotating to increase the strength, screening the prepared granules, and performing surface polishing treatment;

(4) and calcining the polished and screened particles in a rotary kiln at high temperature to obtain the finished casting 3d printing sand.

5. The method of preparing foundry 3D printing sand of claim 4, wherein: in the step (4), the temperature in the rotary kiln is 1200-1600 ℃, and the high-temperature calcination time is 3 h.

6. Use of the foundry 3D printing sand of claim 1 in self-hardening sand casting, lost foam casting, and cold box molding, precoated sand casting.