CN105236906A - Silicate-gypsum composite brick prepared on the basis of diatomite material and preparation method thereof - Google Patents

Abstract

The invention provides a silicate-gypsum composite brick made based on diatomite material and a preparation method thereof. The method includes (1) mixed pulping, (2) wet base preparation, (3) high-humidity cultivation and (4) autoclaving. The invention also provides a preparation method of the composite brick. The composite brick prepared by the method of the invention has the advantages of excellent strength resistance, low drying shrinkage and the like.

Description

A kind of silicate-gypsum composite brick made of diatomite material and its preparation method

technical field

The invention relates to the field of materials, in particular to a silicate-gypsum composite brick and a preparation method thereof.

Background technique

Diatomaceous earth is a kind of biogenic siliceous sedimentary rock. It is a non-metallic mineral that is gradually formed by the natural environment through the deposition of the remains of diatoms that grow in oceans or lakes. Diatomite is mainly distributed in China, the United States, Denmark, France, Romania and other countries. It is a biogenic siliceous sedimentary rock composed mainly of the remains of ancient diatoms. my country's diatomite reserves are 320 million tons, and the prospective reserves are more than 2 billion tons, mainly concentrated in East China and Northeast China. Among them, Jilin (54.8%), Zhejiang, Yunnan, Shandong, Sichuan and other provinces have larger scale and more reserves . The special porous structure of diatomite can be observed under the electron microscope, which has the physical characteristics of fineness, looseness, light weight, porosity, water absorption and strong permeability.

Diatomite has the following advantages: (1) Neutral pH value, non-toxic, good suspension performance, strong adsorption performance, light bulk density, and good mixing uniformity; (2) Diatomite can be used as an additive in cement to increase strength, Make SiO2 active in cement; (3) Diatomaceous earth has excellent extensibility, high impact strength, tensile strength, tear strength, light and soft, good wear resistance, good compressive strength, etc. .

Despite its many advantages, diatomaceous earth is rarely used to make cement bricks, mainly because it is generally considered not a preferred raw material for cement bricks due to its high porosity and high extensibility.

Portland cement bricks usually have the disadvantages of high density and high PH value, which have a corrosive effect on the glass fiber used for reinforcement, and xylitol will be produced in contact with the plant fiber used for reinforcement, thus affecting the bonding strength of cement . However, if Portland cement bricks use vinylon short fiber as a reinforcing material, there are also disadvantages, that is, the refractoriness of the resulting bricks is insufficient, which ultimately affects the overall performance of the Portland cement bricks.

Therefore, there is an urgent need for a method of manufacturing bricks capable of solving one or more of the above-mentioned problems and bricks produced by the method.

Contents of the invention

In order to solve one or more of the above-mentioned problems existing in existing bricks, the present invention provides a silicate-gypsum composite brick and a preparation method thereof.

The present invention provides a kind of method for preparing the composite brick of silicate-gypsum in the first aspect, described method comprises the steps:

(1) Mixing pulping: 2 to 6 parts by weight of sepiolite powder, 0.5 to 2.5 parts by weight of bentonite, 1 to 3 parts by weight of magnesium oxide, 1 to 3 parts by weight of magnesium sulfate, 2 to 4 parts by weight of sodium sulfate, 4 to 6 parts by weight of triethanolamine, 20 to 40 parts by weight of diatomaceous earth and water of equal parts by weight and stir evenly, then further add 5 parts by weight of quicklime and stir uniformly to obtain the first mixture; 20 to 40 parts by weight of plaster of paris, 10 to 20 parts by weight of cement, 20 to 40 parts by weight of fly ash and 4 to 8 parts by weight of glass fiber are stirred uniformly to obtain a second mixture; then the first Stir the mixture evenly with the second mixture to obtain a semi-dry slurry;

(2) wet base preparation: the slurry is made into a wet base;

(3) High-humidity culture: placing the wet body at a relative humidity of 80% to 99% and a normal temperature of 25°C to 35°C for 10 hours to 15 hours to obtain a cultured body;

(4) Autoclave: put the green body in an autoclave, raise the pressure to a saturated vapor pressure of 1.0Mpa to 1.2Mpa in 4 hours to 8 hours, and maintain it under this pressure for 10 to 15 hours , and then reduce the pressure to normal pressure within 4 hours to 8 hours, take it out and dry it, so as to obtain the brick material cured at high temperature.

In a second aspect, the present invention provides a silicate-gypsum composite brick produced by the method described in the first aspect of the present invention.

The silicate-gypsum composite brick prepared by the method of the invention overcomes one or more defects in existing Portland cement bricks and gypsum bricks, and has the advantages of low density and drying shrinkage, high strength, and moisture resistance.

detailed description

The present invention provides a kind of method for preparing the composite brick of silicate-gypsum in the first aspect, described method comprises the steps:

(1) Mixing pulping: 2 to 6 parts by weight of sepiolite powder, 0.5 to 2.5 parts by weight of bentonite, 1 to 3 parts by weight of magnesium oxide, 1 to 3 parts by weight of magnesium sulfate, 2 to 4 parts by weight of sodium sulfate, 4 to 6 parts by weight of triethanolamine, 20 to 40 parts by weight of diatomaceous earth and equal parts of water and stir evenly, then further add 4 to 6 parts by weight of quicklime and stir evenly to obtain the first mixture ; The plaster of Paris of 20 to 40 parts by weight, the cement of 10 to 20 parts by weight, the fly ash of 20 to 40 parts by weight and the glass fiber of 4 to 8 parts by weight are stirred uniformly to obtain a second mixture; stirring the first mixture and the second mixture evenly to obtain a semi-dry slurry;

(2) wet base preparation: the slurry is made into a wet base;

(3) High-humidity culture: placing the wet body at a relative humidity of 80% to 99% and a normal temperature of 25°C to 35°C for 10 hours to 15 hours to obtain a cultured body;

(4) Autoclave: put the green body in an autoclave, raise the pressure to a saturated vapor pressure of 1.0Mpa to 1.2Mpa in 4 hours to 8 hours, and maintain it under this pressure for 10 to 15 hours , and then reduce the pressure to normal pressure within 4 hours to 8 hours, take it out and dry it, so as to obtain the brick material cured at high temperature.

In some preferred embodiments, the 200-mesh sieve residue of the fly ash is 5% by mass.

In some preferred embodiments, the glass fiber has a length of 0.3 mm to 0.5 mm and a diameter of 6 microns to 10 microns.

In some preferred embodiments, the 200-mesh sieve balance of all other solid materials except fly ash and glass fibers is 1% by mass.

In some preferred embodiments, the cement is Type I Portland cement.

In some preferred embodiments, 3 parts by weight of sepiolite powder, 1.5 parts by weight of bentonite, 2 parts by weight of magnesium oxide, 2 parts by weight of magnesium sulfate, 2 parts by weight of sodium sulfate, 5 parts by weight of tris Ethanolamine, 30 parts by weight of diatomaceous earth and water of equal parts by weight are stirred evenly, and then further 5 parts by weight of quicklime are added and stirred uniformly to obtain the first mixture; 30 parts by weight of plaster, 15 parts by weight of cement, Stir 30 parts by weight of fly ash evenly to obtain a second mixture; then stir the first mixture and the second mixture evenly to obtain a semi-dry slurry.

In some preferred embodiments, the high-humidity cultivation is carried out at 90% relative humidity and 30° C. for 12 hours.

In some preferred embodiments, after the pressure is raised to the saturated vapor pressure of 1.1Mpa in 6 hours, and maintained at this pressure for 12 hours, then the pressure is reduced to normal pressure in 6 hours, taken out and Dry in the air to obtain high-temperature cured bricks.

In some preferred embodiments, the pressure is raised to 0.8Mpa for 2 hours and maintained for 1 hour in the boosting process, and then boosted to 1.1Mpa in 3 hours; and 3 hours are used in the depressurization process Reduce the pressure to 0.8Mpa and maintain it for 1 hour, and then reduce the pressure to normal pressure in 3 hours.

Sepiolite is a kind of fibrous hydrated magnesium silicate, which belongs to orthorhombic or monoorthorhombic system; the color is variable, generally pale white or off-white; silky luster, sometimes waxy luster; streaks are White, opaque, smooth to the touch and sticky to the tongue; Mohs hardness is between 2 and 2.5; light weight, density 1 to 2.2g/cm ³ ; low shrinkage, good plasticity, but soluble in hydrochloric acid. The chemical composition of sepiolite is silicon (Si) and magnesium (Mg); its standard crystal chemical formula is Mg ₈ (H ₂ O) 4 [Si ₆ O ₁₆ ] ₂ (OH) ₄ 8H ₂ O, where SiO ₂ content Generally between 54-60%, MgO content is mostly in the range of 21-25%. Sepiolite has strong adsorption, decolorization and dispersion properties, as well as high thermal stability, high temperature resistance up to 1500-1700 ℃, good shape, insulation and salinity resistance. Meerschaum has the unique property that it absorbs a lot of water and becomes soft when exposed to water, but hardens once it dries. Sepiolite powder can be used as suspending agent, anti-sedimentation agent and thickening thixotropic agent.

Bentonite is a hydrous clay mineral mainly composed of montmorillonite. The chemical composition of montmorillonite is: (Al ₂ , Mg ₃ )[Si ₄ O ₁₀ ][OH] ₂ ·nH ₂ O, because it has special properties. Such as swelling, cohesiveness, adsorption, catalysis, thixotropy, suspension and cation exchange. Therefore, it is widely used in various industrial fields. Bentonite is a non-metallic mineral with montmorillonite as the main mineral component. The montmorillonite structure is a 2:1 crystal structure composed of two silicon-oxygen tetrahedrons sandwiching a layer of aluminum-oxygen octahedron. The montmorillonite unit cell is formed. There are some cations in the layered structure, so it has better ion exchange performance.

Without being bound by any theory, the reason why the bricks of the present invention have high strength and low drying shrinkage is that diatomite is used as an additive in cement to make SiO2 active in cement, and quicklime releases heat when it meets water, which is more conducive to The activation of silica in cement, while sepiolite powder and bentonite can be used as suspending agent and thixotropic agent, interacting with diatomite with high adsorption. These components, together with other components, ameliorate the adverse effects of high porosity and high extensibility, so that bricks with high strength and low drying shrinkage can be obtained.

In a second aspect, the present invention provides a silicate-gypsum composite brick prepared by the method described in the first aspect of the present invention.

The present invention will be further described below in conjunction with embodiment. These examples are just examples of preferred implementations of the present invention, and the protection scope of the present invention should not be construed as being limited to these examples.

Example

Hereinafter, the present invention will be further described by means of examples. The raw materials used in the examples are as follows: the 200-mesh sieve rejection of fly ash is 5% by mass; the glass fiber has a length of 0.4 mm and a diameter of 8 micrometers. The 200-mesh sieve balance for all solid materials other than fly ash and glass fibers was 1% by mass. The cement is Type I Portland cement.

Example 1

Present embodiment adopts following steps to manufacture composite brick based on the present invention:

Stir the sepiolite powder, bentonite, magnesium oxide, magnesium sulfate, sodium sulfate, triethanolamine, diatomaceous earth and water in equal parts by weight as shown in the table, and then add quicklime and stir evenly to obtain the first mixed material; mix the plaster of paris, cement, fly ash and glass fiber shown in the table evenly to obtain the second mixture; then stir the first mixture and the second mixture evenly to obtain half dry slurry;

(2) wet base preparation: the slurry is made into a wet base;

(3) High-humidity culture: place the wet body at a relative humidity of about 90% and a normal temperature of 30° C. for 12 hours to obtain a cultured body;

(4) Autoclaved pressure: During the boosting process, use 2 hours to increase the pressure to 0.8Mpa and maintain it for 1 hour, and then use 3 hours to increase the pressure to 1.1Mpa; and use 3 hours to reduce the pressure during the depressurization process to 0.8Mpa and maintain it for 1 hour, and then reduce the pressure to normal pressure in 3 hours, so as to obtain bricks with a length, width and height of 240mm×115mm×53mm after high temperature curing.

Measure each performance index, and the determination method is carried out according to JC239-2001. The measured results are listed in Table 2 below.

Examples 2 to 12

Examples 1 to 12 were carried out in a similar manner to Example 1 except for the contents shown in Table 1.

Table 1 Raw materials and the specific strength of the bricks made therefrom

The performance measurement of the composite brick made in each embodiment of table 2

As can be seen from the results in Table 2, the composite brick made by the present invention has very high strength, which is between M20 and M25 grades. Other performance indicators also meet the standard requirements of JC239-2001.

Claims (10)

1. prepare a method for the composite brick of silicate-gypsum, described method comprises the steps:

(1) mixed pulp: by the diatomite of the trolamine of the sodium sulfate of the magnesium sulfate of the magnesium oxide of the wilkinite of the sepiolite powder of 2 to 6 weight parts, 0.5 to 2.5 weight part, 1 to 3 weight part, 1 to 3 weight part, 2 to 4 weight parts, 4 to 6 weight parts, 20 to 40 weight parts with etc. weight part water in stir, then add the unslaked lime of 4 to 6 weight parts further and stir, obtaining the first compound; The glass fibre of the cement of the plaster of Paris of 20 to 40 weight parts, 10 to 20 weight parts, the flyash of 20 to 40 weight parts and 4 to 8 weight parts is stirred, obtains the second compound; Again described first compound and described second compound are stirred, obtain half-dried slurry;

(2) wet base preparation: described slurry is made wet base;

(3) high humidity is cultivated: by described wet base in relative humidity be 80% to 99% relative humidity and the normal temperature condition of 25 DEG C to 35 DEG C under place 10 little of 15 hours, obtain the base substrate through cultivating;

(4) steam pressure: by described base substrate in autoclave, after in the 4 little times up to 8 hours pressure being raised to the saturated vapor pressure of 1.0Mpa to 1.2Mpa, and maintenance 10 to 15 hours at this pressure, littlely within the time of 8 hours, pressure is dropped to normal pressure 4 again, take out and dry, thus the obtained composite brick through High Temperature Curing.

2. method according to claim 1, wherein, 200 object screen over-sizes of flyash are 5 quality %.

3. method according to claim 1 and 2, wherein, the length of described glass fibre is 0.3mm to 0.5mm, and diameter is 6 microns to 10 microns.

4. 200 mesh sieve margins of the every other solid materials according to the method in any one of claims 1 to 3, wherein, except flyash and glass fibre are 1 quality %.

5. method according to any one of claim 1 to 4, wherein, described cement is I type silicate cement.

6. method according to any one of claim 1 to 5, wherein, by the diatomite of the trolamine of the sodium sulfate of the magnesium sulfate of the magnesium oxide of the wilkinite of the sepiolite powder of 3 weight parts, 1.5 weight parts, 2 weight parts, 2 weight parts, 2 weight parts, 5 weight parts, 30 weight parts with etc. weight part water in stir, then add the unslaked lime of 5 weight parts further and stir, obtaining the first compound; The cement of the plaster of Paris of 30 weight parts, 15 weight parts, the flyash of 30 weight parts are stirred, obtains the second compound; Again described first compound and described second compound are stirred, obtain half-dried slurry.

7. method according to any one of claim 1 to 6, wherein, described high humidity cultivate 90% carry out 12 hours relative to humidity and 30 DEG C.

8. method according to any one of claim 1 to 7, wherein, after the times of 6 hours pressure being raised to the saturated vapor pressure of 1.1Mpa, and maintenance 12 hours at this pressure, within the time of 6 hours, pressure is dropped to normal pressure again, take out and dry, thus the obtained composite brick through High Temperature Curing.

9. method according to any one of claim 1 to 8, wherein, utilizes the time of 2 hours to boost to 0.8Mpa and maintains 1 hour, and then boosting to 1.1Mpa with the time of 3 hours in boost process; And utilize the time of 3 hours to be depressurized to 0.8Mpa in pressure reduction and maintain 1 hour, and then being depressurized to normal pressure with the time of 3 hours.

10. by silicate-gypsum composite brick that the method described in claim 1 to 9 is obtained.