WO2013102288A1

WO2013102288A1 - Tin bath bottom brick of aluminium, calcium and silicon, and method for preparing same

Info

Publication number: WO2013102288A1
Application number: PCT/CN2012/001713
Authority: WO
Inventors: 张启山; 张瑛; 车建壮; 李志军; 孙文礼; 刘杰; 冯延春
Original assignee: 淄博工陶耐火材料有限公司
Priority date: 2012-01-06
Filing date: 2012-12-21
Publication date: 2013-07-11
Also published as: CN102557688B; CN102557688A

Abstract

Disclosed are a tin bath bottom brick and a method for preparing the same, the tin bath bottom brick consisting, in weight percent, of: Al₂O₃ 66%-80%, CaO 17%-28%, SiO₂ 1.5%-5%, and the balance being common mineral impurities. The method comprises: formulating, isostatic pressing and firing at a high temperature, the weight percentages for the formulation being 30%-45% of calcium aluminate coarse particles with a particle size of 3-1 mm, 20%-35% of calcium aluminate medium particles with a particle size of 1-0.1 mm, and 25-40% of fine binding powder with a particle size less than 0.088 mm. The product has a good corrosion resistance to alkali metal oxides, a low thermal expansion, a low thermal conductivity and a low hydrogen diffusion rate.

Description

Aluminum calcium silicon tin bath bottom brick and preparation method thereof

Technical field

The invention relates to a tin trough bottom brick and a preparation method thereof, and belongs to the technical field of refractory materials.

Background technique

The tin bath is the key equipment of the float flat glass production line. The molten glass flows into the tin bath, floats on the tin liquid, and forms a smooth plate glass while advancing. The refractory brick used to store the tin liquid is called the tin bath. Bottom brick. Most of the silica fume clay bricks currently used on the market are in the process of use, because N _3⁄4 0 contained in the glass slowly penetrates into the brick through the tin liquid, forming nepheline and producing volume expansion and thermal stress. When the metamorphic layer containing nepheline is increased to a certain thickness, the metamorphic layer will peel off in a sheet form. Since the specific gravity is lower than that of the tin liquid, when the exfoliated pieces float on the tin liquid surface, the glass surface is scratched and the glass defect is caused.

Book

Researchers at RHI used the alkaline material calcium aluminate to make tin-slot bricks. As described in US5420087, the company uses calcium aluminate coarse particles and fine particles as raw materials and calcium aluminate as the binder. The agent is vibrated and dried in a humid environment, then dried and fired. The utility model is characterized in that the porous calcium aluminate coarse particles and fine particles are used as raw materials, and the hydrated combination of calcium aluminate is used to form the brick body, and the porosity of the 110 CTC after firing is 43%, and the alkali-resistant oxide is eroded and thermally expanded. Calcium aluminate tin trough bottom brick with low rate, low thermal conductivity and low gas permeability. The 5%, Si0 ₂ , Fe ₂ 0, respectively, in order to prevent the reaction of the reaction with the alkali metal oxide and other reactions in the reducing atmosphere, the mass percentage of SiO ₂ and FeA in the raw material should be less than 1.5%, respectively. The content of ₃ is preferably only a small amount. The disadvantage of this brick is that the coarse particles and the fine particles are combined by hydrate. After heat treatment at 1100 °C, the calcium aluminate binding phase still contains a small amount of bound water. During the use of temperature above 1100 °, the combined water will also Overflow, the porosity of the product will increase, which will lead to the risk of use. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an aluminum-calcium-silicate tin-slot bottom brick having a low porosity and a high porosity, which has good alkali metal oxide corrosion resistance, low thermal expansion coefficient, low thermal conductivity, and low hydrogen diffusion rate.

The invention also provides a reasonably easy preparation method.

The aluminum-calcium-silica tin-slot bottom brick (hereinafter referred to as the tin-slot bottom brick) of the present invention has a chemical composition mass percentage including Α1 66-80%, CaO 17-28%, SiO, 0.5-5%. In addition, the impurities in the raw materials exist as the balance, and may contain common mineral impurities such as MgO, N3⁄40, K-.0, and the like.

The preferred chemical composition of the tin bath bottom brick is as follows:

First, the content of Α1Λ is preferably 67% by mass or more, and more preferably 68% by mass or more. On the other hand, the content is below 79% by mass: ά', preferably less than 76% by mass.

The CaO content of the tin-slot bottom brick is preferably 18% by mass or more, and more preferably 21% by mass or more.

^本本 On the other hand, the CaO content is preferably 26% by mass or less, and preferably 25% by mass or less.

The 5% or more of the mass percentage of the SiO ₂ is preferably 1% or more by mass. On the other hand, the content of SiO ₂ is preferably 9% or less by mass%, and preferably 7% or less by mass.

The MgO content of the tin bath bottom brick is preferably 2.5% or less by mass%, preferably 2.3% or less by mass%, and preferably 2.5% by mass or less.

The N3⁄40 content of the tin-sand brick is preferably less than 1% by mass, preferably less than 0.7% by mass, and preferably less than 0.5% by mass.

This tin bottom bricks K ₂ 0 content of 1% or less in mass percent preferably, in mass percentage is preferably 0.8% or less, a percentage of 0.6% or less is preferred in terms of quality.

The 3% or less is preferred, and the mass percentage of 0.4% or less is preferred, and the mass percentage of 0.5% or less is preferred, and the total content of the FeA+Ti0 ₂ is preferably 0.5% or less.

The XRD mineral crystal phase composition of the product is identified as calcium dialuminate, calcium hexaaluminate and calcium aluminum feldspar, which is identified as calcium laurate accounted for 70-90% and calcium aluminum feldspar accounted for 1-25%. It was identified as calcium laurate accounted for 70-90%, calcium hexaaluminate accounted for less than 10%, and feldspar feldspar accounted for 1-25%.

The XRD mineral phase was measured by an X-ray diffraction apparatus using Cu-K of rays. The percentages of calcium laurate, calcium hexaaluminate and calcium aluminum feldspar are calculated as follows:

^CA ~ K _S ^CA1 Is

1 lead

^CM K _S ^CM Is

Wherein, ^C42 represents the percentage of calcium laurate in the sample; ^C46 represents the percentage of calcium hexaaluminate in the sample; ^?£7 represents the percentage of calcium aluminum feldspar in the sample -

J^ s is the calcium diammonate standard substance and the internal standard substance quartz (S). After mixing with a mass ratio of 1:1, the peak intensity of calcium diammonate I (-311) and the internal standard substance of quartz 1 (011) The ratio of peak intensities; S is the calcium hexaaluminate I (114) after mixing the standard material of calcium hexaaluminate with the internal standard substance quartz (S) at a mass ratio of 1:1. The ratio of the 1 (011) peak intensity of the peak material quartz;

Is the ratio of the peak intensity of the calcium aragonite 1 (211) peak to the 1 (011) peak intensity of the internal standard quartz after mixing with the internal standard material quartz (s) at a mass ratio of 1:1; The internal standard substance quartz (s) is mixed with a mass ratio of 1:1, and the peak intensity of the calcium laurate I (-311) is determined;

Is the peak intensity of the calcium hexaaluminate ι (ιΐ4) after the sample and the internal standard substance quartz (s) are mixed at a mass ratio of 1:1;

Say

Igeh is the peak intensity of the calcium aluminum feldspar ι (2ΐ ι) measured after the sample and the internal standard substance quartz (s) are mixed at a mass ratio of 1:1;

Book

It is the peak intensity of the internal standard substance quartz 1 (011) after the sample and the internal standard substance quartz (S) are mixed at a mass ratio of 1:1.

The porosity of the tin bottom brick is 14-28%. From the viewpoint of pressure resistance and the like, the porosity is preferably 26% or less, and the porosity is 24% or less. In terms of productivity, the porosity is above 16% and the productivity is better, and the porosity is above 18%. In addition, the porosity is calculated by the Archimedean method.

The compressive strength of the tin-slot bottom brick is preferably 50 MPa or more, and more preferably 55 MPa or more.

The reasonable and easy preparation method of the tin tank bottom brick is as follows:

The granules of the calcium aluminate having a particle size of 3 to 1 and having a particle diameter of 1 to 0.1. The calcium silicate particles of the calcium silicate are 20 to 35% and the particle diameter is less than 0. 088. The raw material is prepared by a production process of compounding, mixing, molding, and high-temperature firing, and is characterized in that the raw material (weight percentage) comprises: 30-45% of coarse calcium aluminate particles having a particle diameter of 3-1, and a particle diameter of 1 -0. lmm calcium aluminate particles 20-35%, and particle size less than 0. 088 hidden combined fine powder 25-40%. Further, in the present specification, the particle size is determined by a conventional sieve.

Wherein, the porosity of the calcium aluminate raw material is less than 3%, and the mass percentage of the chemical composition comprises: Α1Λ 73-79%, CaO 21-27%, 0. 10% or less of FeA, and the balance may include Ti0 ₂ , The content of MgO, K ₂ O, and Na ₂ 0 is preferably 1% by mass or less, and more preferably 0.1% by mass or less.

The combined fine powder is preferably a mixture comprising a fine powder of calcium aluminate and a fine powder of α-alumina or a fine powder of a siliceous compound, and is combined with fine powder from the viewpoint of the compressive strength of the tin-bottomed brick. From the fine powder of calcium aluminate, the fine powder of α alumina and the fine powder of siliceous compound, the mixture of the three fine powders is: 0:. When the combined fine powder is composed of the above three kinds of fine powders, it is preferable to add a silicon compound fine powder of 0.5 to 5% by mass of the chemical composition of the mixture, and at the same time, according to the mixture of Si0 ₂ The mass percentage is 0.8-1. 4 times the addition of α alumina powder, and the rest is the fine powder of calcium aluminate is preferred. Preferably, at least one of clay, quartz, diopside and wollastonite is used in combination with the siliceous compound in the fine powder.

After the raw material ingredients are mixed, the green body is formed by isostatic pressing, and the molding pressure of the isostatic pressing is preferably set to 50-200 MPa. Prior to isostatic pressing, a general press can be used for preforming as needed. Regarding the manufacturing method of the tin-slot bottom brick, since the molding method is not cast molding (including vibration casting molding), it is not necessary to maintain the cast-formed body in a humid environment, which is advantageous for improving productivity. The method for manufacturing the tin-slot bottom brick has the advantages of high product homogeneity and less crack defects in the product because of the isostatic pressing method.

The green body is dried and then fired in a kiln. The drying method is not particularly limited, and it is naturally dried, or dried using a drying device. In the case of natural drying, it usually takes several days. Specifically, it can be chosen for 1-3 days.

Conditions such as natural drying are preferred.

Regarding the firing conditions, the sintering temperature is preferably 1250-150 CTC, preferably 1270-1470 ° C, and 1300-1450 ° C is preferred. The holding time of the sintering temperature is preferably in 5-50 hours, preferably in 7-45 hours, and preferred in 10-40 hours.

Regarding the firing temperature system, the heating rate is preferably 0.1 ° C / hr - 10 Torr / hour, and preferably 0.5 ° C / hr - 5 ° C / hour. Cooling can be performed by natural cooling or by cooling at a certain cooling rate. An example of a preferred firing temperature regime is as follows:

10°C-200°C Heating rate 1-2T hour

200°C-1300°C Heating rate 1-3 TV hour

1300-1450 °C insulation, holding time is 10-40 hours

The ceasefire cools down and cools naturally.

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

The invention adopts dense calcium aluminate as coarse particles and fine particles, and adds α-alumina powder and siliceous compound powder as a binder, and is formed by isostatic pressing and firing to form calcium aluminate, calcium aluminum yellow feldspar, Calcium hexaaluminate is the main mineral phase product. The product is free of hydrates, has no internal cracking, uniform structure, good resistance to tin liquid penetration, alkali metal oxide corrosion resistance, low thermal expansion rate, low thermal conductivity, low hydrogen diffusion rate, and solves the problem of clay-based tin trough bottom brick. The formation of nepheline by the erosion of alkali metal oxides causes the problem of expansion and peeling of the brick body, can improve the service life of the tin tank bottom brick, and can reduce the glass defects generated by the tin tank bottom brick and the heat loss at the bottom of the tin tank.

detailed description

The invention will now be further described in connection with Example 16.

Example

The physical and chemical indexes of raw materials such as calcium aluminate particles, α-alumina powder, and siliceous compound powder are as follows. In Table 1, the raw materials are added to the kneader in the proportions indicated in Table 2, and after mixing for 5-15 minutes, Isostatic pressing under pressure of 50-200Mpa After the specification is dried, the body is naturally dried for 1-3 days, and then a sample of aluminum-calcium-silica tin-slot bottom brick is prepared by firing at 1300Ό- 50 'C, and its chemical composition, mineral phase composition, porosity, bulk density and compressive strength are measured. Physical and chemical properties such as thermal conductivity are shown in Table 2 of the specific examples. Table] Quality Chemical Percent Composition Table of Raw Materials

Table 2. Table of specific examples

^Example

1 2 3 4 5 6

Implementation measures

3 - 1 leucoaluminate % 40 45 35 35 35 30

1-0. 1mm calcium aluminate % 25 25 30 25 25 30

<0. 088 face quartz clay diopside diopside wollastonite wollastonite siliceous compound % 4 7 5 8 2 9

<0. 088mm

5 4 2 4 2 5

--alumina powder %

<0. 088 painting

26 19 28 28 36 26 Calcium aluminate powder %

Firing temperature 1450°C 1300°C 1360 1400 °C 1380Ό 1420°C Holding time (hours) 18 10 10 40 28 34

Porosity % 18.1 18. 6 20. 4 20. 3 19. 3 19. 0 Bulk density g/cm ^: ' 2. 42 2. 38 2. 35 2. 32 2. 36 2. 37 Compressive strength Mpa 57 80 52 67 70 75 Breathability chat 0.9 0.9 0.8 0.8 0.5 0.4 Hydrogen diffusivity mmH20 74 75 80 10 30 10

Thermal expansion rate %

0.74 0.72 0.68 0.66 0.66 0.65

(1200Ό)

Plate method thermal conductivity

0.76 0.74 0.77 0.60 0.62 0.65

W/m* K (1000°C)

Si(3⁄4 4.11 3.36 2.87 4.60 1.15 4.65

ALO, 73.7 74.4 72.5 70.5 74.5 69.9

Fe _L , 0 ₃ 0.08 0.10 0.09 0.09 0.10 0.15

Ti0 0.03 0.03 0.03 0.03 0.03 0.03

CaO 21.1 21.1 22.6 22.3 23.1 24.0 gO 0.50 0. Say 50 1.43 1.95 0.55 0.56

K,0 . 0.07 0.09 0.07 0.07 0.07 0.06

N3⁄40 0.20 0.26 0.20 0.20 0.21 0.19

A a doctor

99.79 99.84 99.79 99.74 99.71 99.54 book

Calcium dialium triphosphate % 74 80 86 72 87 70 Calcium aluminum yellow feldspar % 18 17 10 20 3 22 Calcium hexaluminate % 5 2 0 2 8 5

Mixing quantity ** % 97 99 96 94 98 97 The mineral composition of MgO, N3⁄40 and other minerals in the aluminum-calcium-silica tin-slot bottom brick forms a small amount of magnesium-aluminum spinel or glass phase, so the main mineral phase calcium dialuminate, calcium aluminum yellow feldspar The combined amount of calcium hexaaluminate is less than 100%.

Claims

Claim

1, an aluminum tin calc-silicate brick bottom, characterized in that the mass percentage of a chemical composition comprising Α1Λ 66 80%, CaO 17 - 28%, Si0 2 0. 5-5%.

2. The aluminum-calcium siliceous tin-bottom tile according to claim 1, wherein the mass percentage of the chemical composition comprises AL0 _:1 67 - 76%, CaO 21 - 28%, and Si0 ₂ 1. 5-5%.

3. The aluminum-calcium siliceous tin-bottom tile according to claim 1, wherein the XRD mineral phase composition of the product comprises 70-90% of calcium laurate and 1-25% of calcium aluminum feldspar.

The aluminum-calcium siliceous tin-bottomed brick according to claim 3, wherein the XRD mineral phase composition of the product contains 10% or less of calcium hexaaluminate.

The aluminum-calcium siliceous tin-bottomed brick according to claim 1, wherein the product has a porosity of 18 24%.

6. A method for preparing an aluminum-calcium-silicate tin-slot bottom brick according to claim 1, which is prepared by batching, isostatic pressing, and high-temperature firing, and is characterized in that the raw material comprises: a particle size of 3 - 1 The calcium aluminate coarse particles 30-45%, the particle size is 1-0. Imm calcium aluminate particles 20-35%, the particle size is less than 0. 088 implicit combined fine powder Ζδ- ¹ ^

7. The method for preparing an aluminum-calcium siliceous tin trough bottom brick according to claim 6, wherein the calcium aluminate raw material has a porosity of less than 3%, and the mass percentage of the chemical composition comprises: Α1Λ 73-79%, CaO 21-27%, 0. 10% or less ί1⁄2Λ.

The method for preparing an aluminum-calcium siliceous tin trough bottom brick according to claim 6, wherein the fine powder is a mixture of calcium aluminate fine powder, α-alumina fine powder and siliceous compound fine powder, The SiO ₂ powder is added in an amount of 0.5 to 5% by weight of the SiO _{2 , and the} amount of SiO ₂ is 0. 8-1. 4 times. Calcium fine powder.

The method for preparing an aluminum-calcium siliceous tin trough bottom brick according to claim 8, wherein the siliceous compound in the fine powder is at least one selected from the group consisting of clay, quartz, diopside and wollastonite.

The method for preparing an aluminum-calcium siliceous tin trough bottom brick according to claim 6, wherein after the raw materials are mixed, the green body is formed by isostatic pressing, and the molding pressure is 50-200 MPa.

The method for preparing an aluminum-calcium siliceous tin trough bottom brick according to claim 6, wherein the green body is dried and fired, the firing temperature is 1300-50 ° C, and the baking heat preservation time is 10-40 hours. .