CN108358655B - Foamed ceramic material taking basalt wire drawing tailings as raw material and preparation method thereof - Google Patents

Abstract

The invention discloses a foam ceramic material using basalt wire drawing tailings as a raw material and a preparation method thereof. The foam ceramic material uses the tailings after basalt wire drawing and beneficiation as the raw material, silicon carbide as the foaming agent, and water glass as the molding The agent is prepared by powder sintering method. The preparation process of the invention is extremely simple, the solid waste is used as the raw material and the cost is low, the density, strength and thermal conductivity of the obtained foamed ceramic products can meet the national standards and building materials industry standards, and the industrialized production and preparation of similar foamed ceramic products are provided. The preparation process has broad development prospects in the fields of green thermal insulation building materials and thermal insulation materials for large-scale industrial equipment.

Description

Foamed ceramic material taking basalt wire drawing tailings as raw material and preparation method thereof

Technical Field

The invention relates to a foamed ceramic material taking basalt wire drawing tailings as a raw material and a preparation method thereof.

Background

With the rapid development of economy in China, the contradiction between energy and environmental protection is increasingly prominent. Building energy conservation has been highly regarded as the key point of energy-saving work, and the aim is to reduce energy consumption of buildings and environmental pollution. In winter in northern China, the cold is severe. Under the climatic conditions of extremely hot summer and the like in south, the heat insulation building material becomes a hotspot in the research field of energy-saving buildings in China, so the development and design of the novel green heat insulation wall material is also a hotspot in the research field of materials.

China has abundant basalt mineral resource distribution in Jilin, Fujian, Shandong, Yunnan, Sichuan and the like, so research personnel develop basalt fibers which can be widely applied to the military industry and civil fields of aerospace, construction, chemical industry, medicine, electronics, agriculture and the like by utilizing basalt. However, the requirement on basalt raw materials is high in the manufacturing process, for example, the high iron oxide content or the high silicon dioxide content in basalt directly causes large performance fluctuation of basalt fibers, so that the large application of the basalt fibers in high-end fields is limited. Therefore, the basalt wire drawing raw material needs to be subjected to mineral processing operation, a large amount of tailings are left after the mineral processing operation, but an effective solution cannot be obtained for the treatment of the tailings. The invention relates to a process for preparing high-performance foamed ceramic by utilizing basalt wiredrawing tailings, which realizes the reutilization of solid wastes.

The foamed ceramic is a third-generation porous ceramic product developed after common porous ceramic and honeycomb porous ceramic, is in a foamed porous shape in modeling, has three-dimensional communicated pore channels, can be properly adjusted in shape, pore size, specific surface area, permeability and chemical performance by a process, and is used as a novel porous ceramic material with a three-dimensional net structure. The process of preparing foamed ceramic by scholars at home and abroad is generally complex, for example, Kovarik et al (Materials Letters,2017,209.) use an organic foam impregnation method to prepare open-cell foamed ceramic material, while the foamed ceramic sample prepared by the simple preparation process has poor comprehensive performance, such as Yi-Chong Liao (Ceramics International,2012,38,4415 and 4420) uses sodium carbonate as a foaming agent and riverbed sludge as raw Materials to prepare foamed ceramic, and the foamed ceramic is prepared by the simple sintering method, but the density of the foamed sample prepared by the preparation process is high, and the minimum density is 0.81g/cm³The compressive strength is 1.07 MPa.

Disclosure of Invention

In order to solve the problems existing in the preparation process, the invention provides a foamed ceramic material taking basalt wire-drawing tailings as a raw material and a preparation method thereof, aiming at simplifying the preparation process of the foamed ceramic and reducing the manufacturing cost of a foam sample, so that the foamed ceramic material can be applied to the field of building materials on a large scale.

The invention relates to a foamed ceramic material taking basalt wire drawing tailings as a raw material, which comprises the following raw materials in parts by weight:

68-78 parts of basalt wire-drawing tailings, 2-6 parts of silicon carbide and 15-25 parts of water glass.

The modulus of the water glass is 2.5.

The proportion is the preferable proportion found by the inventor through experiments, and the foamed ceramic meeting the national standard can be prepared by adjusting the proportion of the basalt wire drawing tailings, the silicon carbide and the like in an optional range. However, it should be noted that, since the number of tests is limited, other possible ratios not falling within the above-mentioned optional ranges are not excluded.

The foamed ceramic material is prepared by taking tailings obtained after basalt wiredrawing and mineral dressing as a raw material, silicon carbide as a foaming agent and water glass as a forming agent by adopting a powder sintering method.

The invention relates to a preparation method of a foamed ceramic material taking basalt wiredrawing tailings as a raw material, which comprises the following steps:

step 1: crushing the basalt wiredrawing tailings, mixing the crushed basalt wiredrawing tailings with silicon carbide according to a proportion, and uniformly grinding to obtain a mixture;

step 2: adding water glass into the mixture obtained in the step 1, and if the solid-phase material cannot be fully wetted, adding a proper amount of purified water, and fully and uniformly mixing;

and step 3: injecting the material obtained in the step (2) into a mold, performing pre-pressing molding at room temperature, then standing for aging, and finally demolding to obtain a precursor;

and 4, step 4: and placing the obtained precursor in a muffle furnace for calcining, and then cooling to room temperature along with the furnace to obtain the light high-strength foam ceramic heat-insulating material.

In the step 1, the basalt wiredrawing tailings are crushed and sieved by a 100-mesh sieve, and then are mixed with silicon carbide according to a proportion.

In the step 3, the temperature for standing and aging is room temperature, and the time is 4-8 h.

In the step 4, the calcining temperature is 1100-1150 ℃, the calcining time is 15-45 min, and the heating rate is 6-8 ℃/min.

The above-mentioned preferable conditions are also the preferable execution conditions of the steps of pulverization, calcination, etc. found by the inventors through experiments, and can be flexibly adjusted according to the change of the raw material ratio, the difference of the equipment state, etc.

The invention has the beneficial effects that:

1. the invention takes the basalt wiredrawing tailings which are widely distributed as the main material. The basalt wiredrawing tailings have natural pore canal structures inside due to production reasons, and the basalt wiredrawing tailings mainly have non-clay minerals such as feldspar pyroxene and the like, and have relatively high hardness, so the basalt wiredrawing tailings have natural advantages when being used as a raw material of a foamed ceramic material.

2. The invention takes silicon carbide as a foaming agent and water glass as a forming agent, has low raw material cost and simple process, and is easy for industrial production, so the preparation process can be used in the fields with more materials such as heat-insulating building materials and large-scale heat-insulating industrial equipment.

3. The invention uses water glass as a forming agent, and the alkaline Na in the water glass₂The function of O, added into the mixed material, also plays the role of a cosolvent.

4. The foamed ceramic sample prepared by the method has the advantages of small heat conductivity coefficient, light weight and strength 3 times higher than national and industrial standards, and the performances of the heat conductivity coefficient, the strength and the like meet the requirements of American society for testing and materials ASTM C552-14, so that the foamed ceramic sample is a light high-strength heat insulation material.

Drawings

FIG. 1 is a flow chart of the preparation of the foamed ceramic thermal insulation material of the present invention.

FIG. 2 is a diagram of a foamed ceramic thermal insulation material obtained in example 1 of the present invention.

FIG. 3 is an XRD diagram of the foamed ceramic thermal insulation material and basalt wiredrawing tailing raw material obtained in example 1 of the present invention.

Detailed Description

The following examples are given to illustrate the present invention, and the following examples are carried out on the premise of the technical solution of the present invention, and give detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following examples.

The basalt wiredrawing tailings used in the following examples are prepared from the basalt wiredrawing tailings of willow river in the city of Tonghua of Jilin province, and the used water glass is industrial-grade water glass with the mole number of 2.5; the silicon carbide blowing agent used was 99% pure.

Example 1:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 3.5 parts of silicon carbide and 22 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method of the foamed ceramic material taking the basalt wiredrawing tailings as the raw material in the embodiment comprises the following steps:

1. crushing the basalt wiredrawing tailings, sieving the crushed basalt wiredrawing tailings with a 100-mesh sieve, mixing the crushed basalt wiredrawing tailings and silicon carbide according to a proportion, and uniformly grinding to obtain a mixture;

2. adding water glass into the mixture obtained in the step 1, and fully and uniformly mixing;

3. injecting the material obtained in the step (2) into a mold, pre-pressing and molding at room temperature, standing and aging at normal temperature for 6 hours, and finally demolding to obtain a precursor;

4. and placing the obtained precursor in a muffle furnace, firstly heating to 750 ℃ and preserving heat for 20min, then continuously heating to 1100 ℃ and preserving heat for 45min, and then cooling to room temperature along with the furnace to obtain the light high-strength foamed ceramic heat-insulating material.

Fig. 2 and 3 are a physical diagram and an XRD diagram of the foamed ceramic thermal insulation material obtained in this example, respectively.

Example 2:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 6 parts of silicon carbide and 22 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method in this example is the same as that in example 1.

Example 3:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 3.5 parts of silicon carbide and 17 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method in this example is the same as that in example 1.

Example 4:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 3.5 parts of silicon carbide and 25 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method in this example is the same as that in example 1.

Comparative example 1:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 3.5 parts of silicon carbide and 8 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method in this example is the same as that in example 1.

Comparative example 2:

in the embodiment, the foamed ceramic material taking basalt wire drawing tailings as a raw material comprises the following raw materials in parts by mass:

74 parts of basalt wire-drawing tailings, 10 parts of silicon carbide and 22 parts of water glass. Specifically, the mass of the basalt wiredrawing tailings is 50 g.

The preparation method in this example is the same as that in example 1.

The properties of the foamed ceramic materials obtained in the above examples and comparative examples are shown in Table 1, the properties in the American society for testing and materials Standard ASTMC552-14 are shown in Table 2, and the properties of the samples in the Chinese national Standard GB/T33500-.

TABLE 1

TABLE 2

TABLE 3

By testing the performance of the foamed ceramic thermal insulation material obtained in each example and comparing the test results with the performance in ASTM C552-14 and GB/T33500-. In addition, as can be seen from comparative example 1, when the weight part of the water glass is less, the sample can not be sufficiently softened at 1100 ℃, so that the precursor can not be sufficiently foamed under the condition of the same weight part of the silicon carbide foaming agent, the thermal conductivity coefficient and the density of the sample are increased, and the compressive strength is increased; as can be seen from comparative example 2, when excessive foaming agent silicon carbide is added, a large number of bubbles of the precursor are separated out and gathered, so that the density of the precursor is reduced sharply, the heat conductivity coefficient of the foam sample is increased along with the occurrence of the connecting holes, and the compressive strength of the foam sample is obviously reduced. Therefore, the product performance can not meet the national standard requirement when the weight of the water glass is too small and the weight of the foaming agent silicon carbide is too high.

The present invention is not limited to the above exemplary embodiments, and any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (4)

1. A preparation method of a foamed ceramic material taking basalt wiredrawing tailings as a raw material is characterized by comprising the following steps:

step 1: crushing the basalt wiredrawing tailings, mixing the crushed basalt wiredrawing tailings with silicon carbide according to a proportion, and uniformly grinding to obtain a mixture;

step 2: adding water glass into the mixture obtained in the step 1;

and step 3: injecting the material obtained in the step (2) into a mold, performing pre-pressing molding at room temperature, then standing for aging, and finally demolding to obtain a precursor;

and 4, step 4: placing the obtained precursor in a muffle furnace for calcination at 1100-1150 ℃ for 15-45 min, and then cooling to room temperature along with the furnace to obtain the light high-strength foamed ceramic heat-insulating material;

the foamed ceramic material comprises the following raw materials in parts by weight:

68-78 parts of basalt wire-drawing tailings, 2-6 parts of silicon carbide and 15-25 parts of water glass;

the modulus of the water glass is 2.5.

2. The method of claim 1, wherein:

in the step 1, the basalt wiredrawing tailings are crushed and then screened by a 100-mesh sieve, and then are mixed with silicon carbide according to a proportion.

3. The method of claim 1, wherein:

in the step 3, the temperature for standing and aging is room temperature, and the time is 4-8 h.

4. The method of claim 1, wherein:

the heating rate is 6-8 ℃/min.

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