Zircon composite material resistant to high-alkali glass corrosion and preparation method thereof

Abstract

The present invention discloses a zircon composite material resistant to high-alkali glass corrosion and a preparation method thereof, and relates to the technical field of zircon products. The technical scheme is as follows: comprising the following components in mass percentage, wherein the total mass of the remaining components except the organic binder is 100%, and the organic binder is calculated as a percentage of the total mass of the remaining components: zircon powder 94.2-99%, yttrium phosphate powder 0.25-4.3%, modifier 0.15-1%, sintering agent 0.2-0.6%, organic binder 0.1-0.5%; wherein the modifier is aluminum dihydrogen phosphate powder or phosphoric acid solution. The present invention solves the problem of decomposition of zircon materials when they come into contact with high-alkali glass above 1050°C, and expands the application range of zircon materials.

Description

Technical Field

[0001] The invention relates to the technical field of zircon products, and in particular to a zircon composite material resistant to high-alkali glass corrosion and a preparation method thereof. Background Art

[0002] Zircon material has the advantages of low thermal expansion rate, high temperature resistance, good thermal shock resistance, excellent resistance to slag and alkali-free glass erosion, etc. It is widely used in the crown feet, fire-watching holes, detection holes, breast walls of the melting part, and the sealing layer of the bottom of the pool of the glass melting furnace. Existing technology has conducted a lot of research on zircon materials for glass furnaces:

[0003] Chinese invention patent CN102584286A discloses a creep-resistant zircon refractory material used in a glass manufacturing system, which has a composition including the following components: ZrSiO 4 :98.85-99.68wt.%; ZrO 2 :0.01-0.15wt.%TiO 2 :0.23-0.5wt.%;Fe 2 O 3 : 0.08-0.6wt.%. This patent mainly improves the creep resistance of overflow bricks by controlling the addition of titanium oxide and iron oxide.

[0004] Chinese invention patent CN102036934B discloses a low strain rate modified zircon material and product, which uses zircon particles with a multi-peak particle size distribution curve, at least 0.1% by weight of TiO 2 and up to 10% by weight of Y 2 O 3 The method of mixing and isostatic pressing to form a green body and sintering at least at 1500°C to obtain a dense zircon material adopts a multi-level particle grading to improve the packing density of the product and minimize the porosity to reduce the grain boundary concentration and improve the bonding strength between the grain boundaries of the zircon particles.

[0005] Chinese invention patent CN101842325A discloses low creep zircon containing nano additives and a preparation method thereof, wherein type I, II, III additives and their combination are added to zircon, wherein the content of type I additive is 0.0-0.1wt.%, selected from Fe 2 O 3 SnO 2 , oxide glass and mixtures and combinations thereof; Class II additives account for 0.1-0.8wt.%, selected from TiO 2 、SiO 2 , VO 2, CoO, NiO, NbO and mixtures and combinations thereof; Class III additives account for 0.1-0.8wt.%, selected from Y 2 O 3 、ZrO 2 、CaO、MgO、Cr 2 O 3 、Al 2 O 3 And mixtures and combinations thereof; wherein the amount of the sintering agent is calculated as oxide, based on the percentage of the total weight of the composition, and the prepared composite material has a low creep rate and good strength at high temperature.

[0006] Chinese invention patent CN105541411A discloses zircon-based refractory products, which use ceramic phases to fill the surface pores of zircon-based refractory products, significantly reducing the surface open pores and pore diameters to provide zircon-based refractory materials with improved performance. 50wt.% chemically pure tetraethyl orthosilicate and 50wt.% chemically pure isopropanol are mixed to form an impregnation solution, in which zircon refractory products are impregnated and sintered at 1000°C for 2h to form silicon oxide ceramic phase fillers in the surface pores to improve corrosion resistance.

[0007] Zircon bricks have good resistance to erosion by alkali-free glass liquid and can be in contact with alkali-free glass liquid, but they will not be able to withstand the erosion of high-alkali glass (calculated as oxide, Na in glass) such as soda-lime glass and high-aluminum high-alkali cover glass. 2 O+K 2 O+Li 2 O≥5wt.%), zircon will decompose into zirconium oxide and silicon oxide at above 1050℃, and zirconium oxide crystal peeling is easy to form glass defects, thus limiting the use temperature range of zircon bricks in contact with glass. For example, Chinese invention patent CN102442760A discloses a high static fatigue alumina isopipe, in which the alkali content disclosed in Example 1 is above 10wt.%, specifically 13.75wt.%, which is mainly Na 2 O and a small amount of K 2 O glass, at 1214℃, contacts zircon to form worm-like or fish egg-like zirconium oxide. The appearance of this zirconium oxide leads to zirconium oxide defects in the glass, making the zircon material incompatible when used together with high-alkali glass.

[0008] Therefore, it is necessary to improve the existing technology to find a way to inhibit the decomposition of zircon when it contacts high-alkali glass at temperatures above 1050°C, and to expand the application range of zircon materials in glass kilns. Summary of the invention

[0009] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide a zircon composite material resistant to high-alkali glass erosion and a preparation method thereof, to solve the problem of decomposition of zircon material when it contacts high-alkali glass at temperatures above 1050°C, and to expand the application range of zircon material.

[0010] The technical solution of the present invention is:

[0011] On the one hand, the present invention provides a zircon composite material resistant to high-alkali glass corrosion, comprising the following components in percentage by mass, wherein the total mass of the remaining components except the organic binder is 100%, and the organic binder is calculated as a percentage of the total mass of the remaining components: zircon powder 94.2-99%, yttrium phosphate powder 0.25-4.3%, modifier 0.15-1%, sintering promoter 0.2-0.6%, and organic binder 0.1-0.5%; wherein the modifier is aluminum dihydrogen phosphate powder or phosphoric acid solution.

[0012] Preferably, in the zircon powder, Al 2 O 3 <0.35wt.%Fe 2 O 3 <0.15wt.%TiO 2 <0.15wt.%SiO 2 >32.7wt.%ZrO 2 >65.5wt.%.

[0013] Preferably, in the yttrium phosphate powder, YPO 4 ≥99.99wt.%, the crystal form is xenotime.

[0014] Preferably, the concentration of the phosphoric acid solution is 85 wt.%.

[0015] Preferably, the sintering agent is titanium oxide powder, wherein TiO 2 >98.5wt.%, the crystal form is rutile.

[0016] Preferably, the organic binder is polyvinyl alcohol.

[0017] On the other hand, the present invention provides a method for preparing the above-mentioned zircon composite material resistant to high-alkali glass corrosion, comprising the following steps:

[0018] S1: Mixing the components into a batch;

[0019] S2: wet grinding and spray granulation of the batch materials to form granulated powder, and isostatic pressing the granulated powder to obtain a green body;

[0020] S3: Sintering the green body to obtain a zircon composite material resistant to high-alkali glass corrosion.

[0021] Preferably, in step S2, the isostatic pressing pressure is 80-180 MPa.

[0022] Preferably, in step S2, the median diameter of the particles in the slurry obtained after wet grinding is 4-9 μm. The main function of wet grinding is to adjust the particle size of the zircon powder particles so that the yttrium phosphate powder, modifier and sintering agent are evenly distributed among the zircon powder particles.

[0023] Preferably, in step S3, the sintering temperature is 1510-1580°C.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The zircon composite material resistant to high-alkali glass corrosion prepared by the present invention has a volume density of ≥4.35g / cm 3 , apparent porosity ≤0.6%; and compared with the decomposition phenomenon of existing zircon products at the 1050℃ corrosion interface, there is no zircon decomposition phenomenon at the 1050℃, 1150℃ or even 1300℃ corrosion interface in contact with high-alkali glass, and the decomposition temperature is increased by 100-250℃, which solves the problem of decomposition of zircon material when contacting high-alkali glass above 1050℃ and expands the application range of zircon material.

[0026] 2. The present invention adds yttrium phosphate powder and a modifier, and obtains a dense product at a relatively low temperature or close to the sintering temperature of zircon material 1510-1580°C, solving the problem that yttrium phosphate and zircon composite materials are difficult to sinter. The zircon composite material resistant to high-alkali glass corrosion prepared by the present invention has a foaming index of only 1-2 at 1300°C, which is significantly lower than the foaming level of existing zircon products. The preparation method of the present invention is simple, easy to operate, scientific and reasonable, and convenient for large-scale industrial production. DETAILED DESCRIPTION

[0027] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0028] In the following examples, the zircon powder used includes the following components in percentage by weight: 0.3 wt.% Al 2 O 3 、0.1wt.%Fe 2 O 3 、32.85wt.%SiO 2 、0.13wt.%TiO 2 , 0.09wt.%P 2 O 5 、66.1wt.% ZrO2 , the rest is K 2 O、Na 2 O, CaO, MgO and other trace impurities; the median diameter of zircon powder is 14μm. 4 ≥99.99wt.wt.%, the crystal form is xenotime, Y 2 O 3 The content is 61.43wt.%, P 2 O 5 The content is about 38.56wt.%, basically free of other impurities, and the median diameter of the powder is 5μm. 2 The content is 99.1wt.%, the crystal form is rutile, and the median diameter of the powder is 3μm. The concentration of the modifier phosphoric acid solution is 85wt.%.

[0029] The preparation method of the zircon composite material resistant to high-alkali glass corrosion in the following embodiment comprises the following steps:

[0030] S1: Mixing the components into a batch;

[0031] S2: The batch material is subjected to wet grinding and spray granulation to form granulated powder, and the granulated powder is isostatically pressed to obtain a green body; wherein the wet grinding is to add the batch material into a ball mill according to the mass ratio of zirconia balls, batch material and water of 2:2:1, and grind to obtain a slurry after grinding; after the slurry is spray granulated, the formed granulated powder is loaded into a mold, pressurized and then reduced to normal pressure to obtain a green body with a length of 400 mm, a thickness of 300 mm and a width of 300 mm;

[0032] S3: After the green body is naturally dried for 2 days, it is placed in a gas-fired kiln for sintering to obtain a zircon composite material resistant to high-alkali glass corrosion.

[0033] In the following examples, the particle sizes are all measured by a laser particle size analyzer, and the median diameter refers to the particle size corresponding to when the cumulative particle size distribution percentage of the sample reaches 50%.

[0034] Examples 1-8

[0035] The formula and process parameters of the zircon composite materials resistant to high-alkali glass corrosion of Examples 1-8 are shown in Table 1.

[0036] Comparative Example 1

[0037] The difference from Example 3 is that no yttrium phosphate powder is added in Comparative Example 1, and its formula and process parameters are shown in Table 2.

[0038] Comparative Example 2

[0039] The difference from Example 4 is that no yttrium phosphate powder is added in Comparative Example 2, and its formula and process parameters are shown in Table 2.

[0040] Comparative Example 3

[0041] The difference from Example 7 is that no aluminum dihydrogen phosphate powder is added in Comparative Example 3, and its formula and process parameters are shown in Table 2.

[0042] Comparative Example 4

[0043] The difference from Example 8 is that no aluminum dihydrogen phosphate powder is added in Comparative Example 4, and its formula and process parameters are shown in Table 2.

[0044] Comparative Example 5

[0045] The difference from Example 1 is that the content of yttrium phosphate powder is 0.05 wt.%.

[0046] Comparative Example 6

[0047] The difference from Example 1 is that the content of yttrium phosphate powder is 5 wt.%.

[0048] Comparative Example 7

[0049] The difference from Example 1 is that the added amount of phosphoric acid solution is 0.1 wt.%.

[0050] Comparative Example 8

[0051] The difference from Example 1 is that the added amount of phosphoric acid solution is 1.4 wt.%.

[0052] Comparative Example 9

[0053] The difference from Example 1 is that yttrium silicate powder with a median diameter of 3 μm and a purity of 99.5 wt.% is used instead of yttrium phosphate powder.

[0054] Comparative Example 10

[0055] The difference from Example 1 is that yttrium stabilized zirconium powder is used instead of yttrium phosphate powder, and the Y in the yttrium stabilized zirconium powder is 2 O 3 The content is 14.97wt.%, ZrO 2 The content is 84.83wt.%, and it basically does not contain other impurity components. The median diameter of the powder is 2μm, and the yttrium content in the yttrium-stabilized zirconium powder is the same as the yttrium content in the yttrium phosphate powder in Example 1.

[0056] Table 1 Formulations and process parameters of Examples 1-8

[0057]

[0058] Table 2 Formula and process parameters of comparative examples 1-10

[0059]

[0060] The performance of the zircon composite materials of Examples 1-8 and Comparative Examples 1-10 was tested in the following manner:

[0061] The bulk density and porosity are tested in accordance with GB / T 2997-2015 Test method for bulk density, apparent porosity and true porosity of dense shaped refractory products.

[0062] The room temperature compressive strength is tested with reference to GB / T 5072-2023 Test method for room temperature compressive strength of refractory materials.

[0063] The main component of the high-alkali glass used in the following corrosion test and foaming test is Na 2 O and K 2 O is about 13wt.%, Al 2 O 3 About 23wt.%SiO 2 It is about 63wt.%, and is a common commercially available high-aluminum and high-alkali cover glass.

[0064] The erosion test was carried out in accordance with "JC / T 806-2017 Test method for static erosion resistance of refractory materials for glass kilns": the sample size was 12 mm in diameter and 70 mm in length. The test conditions were 1050°C × 100 h, 1150°C × 100 h, and 1300°C × 100 h, respectively. After erosion, the sample was cut in half longitudinally, the part attached to the glass was ground and polished, and observed under a polarizing microscope × 300-400 times. If zircon decomposed into baddeleyite, the temperature was no longer increased for the test.

[0065] The foaming test was carried out in accordance with JC / T 639-2017 Test method for bubble precipitation rate of refractory materials for glass kilns: the sample size was 50mm×50mm×10mm, the test conditions were 1300℃×6h, and a glass column made by melting high-alkali glass was placed on the surface of the sample.

[0066] The test results are shown in Table 3-4.

[0067] Table 3 Performance test results of zircon composite materials resistant to high-alkali glass corrosion of Examples 1-8

[0068]

[0069] Table 4 Performance test results of zircon composite materials of Comparative Examples 1-10

[0070]

[0071] As shown in Table 3, the zircon composite materials resistant to high-alkali glass corrosion obtained in Examples 1-8 have an apparent porosity of 0.1-0.6% and a bulk density of 4.35-4.45 g / cm after firing. 3 , compared with the foaming index of high alkali glass at 1300°C which is mostly 1; and compared with the existing zircon material that decomposes when it contacts high alkali glass at 1050°C, the erosion temperature of the high alkali resistant glass in Examples 4-5 is increased by at least 100°C, and the erosion temperature of the high alkali resistant glass in the other examples is increased by at least 250°C.

[0072] Compared with Comparative Examples 1-2, Example 3-4 adds yttrium phosphate powder, and the volume density of the prepared zircon composite material is high. There is no zircon decomposition phenomenon at the corrosion interface with high-alkali glass at 1300℃×100h, and the usable temperature is also increased by 250℃. In Comparative Examples 1-2, although the addition of phosphoric acid solution alone has a certain sintering effect, the volume density of the sample does not exceed 4.3g / cm 3 , and the foaming index is 2 times higher than that of Example 3-4. This indicates that after high-temperature sintering, the effective components of phosphoric acid solution added alone, phosphate or phosphorus pentoxide, cannot inhibit the decomposition of zircon.

[0073] In Example 7-8, aluminum dihydrogen phosphate powder was added as a modifier, and the volume density of the prepared zircon composite material was 4.43 g / cm 3 and 4.4 g / cm 3 , the porosity is only 0.2% and 0.1%. Compared with the comparative examples 3-4 without adding the modifier, the apparent porosity and bulk density are significantly improved, and there is no zircon decomposition phenomenon at the corrosion interface with high-alkali glass at 1300℃×100h, and the foaming index is also significantly improved. In addition, in comparative examples 3-4, yttrium phosphate can significantly inhibit sintering, and the bulk density of the sample is only 4.26g / cm 3 and 4.08g / cm 3 , the apparent porosity reaches 6% and 9%, and the foaming index is 3. This indicates that when yttrium phosphate is added alone, the material is difficult to densify during sintering, resulting in easy penetration of high-alkali glass in the sample, and yttrium phosphate itself may have a certain foaming property in high-alkali glass, which has no effect on inhibiting the decomposition of zircon.

[0074] By comparing Example 1 with Comparative Examples 5-8, it can be seen that when yttrium phosphate powder and phosphoric acid solution as a modifier are added at the same time, but the amount of yttrium phosphate powder and phosphoric acid solution added is too much or too little, the volume density of the sample after sintering is low, and the foaming index of high-alkali glass at 1300°C is still high, but there is no zircon decomposition phenomenon at least at 1050°C. It further illustrates that the reaction product after high-temperature sintering after adding yttrium phosphate powder and phosphoric acid solution as a modifier can inhibit the decomposition of zircon, but when the amount of yttrium phosphate powder and phosphoric acid solution added is not appropriate, the effect of inhibiting decomposition is very limited.

[0075] By comparing Example 1 with Comparative Example 9, it can be seen that when yttrium silicate powder and modifier phosphoric acid solution are added, the volume density of the sintered sample is low, and the foaming index of the high-alkali glass at 1300°C is high. The sample has zircon decomposition phenomenon at 1050°C, which shows that in the present invention, when phosphoric acid solution and yttrium phosphate powder are added together, the reaction product after high-temperature sintering can inhibit the decomposition of zircon, while when phosphoric acid solution and yttrium silicate powder are added together, this effect cannot be achieved.

[0076] By comparing Example 1 with Comparative Example 10, it can be seen that when yttrium-stabilized zirconium powder and phosphoric acid solution as a modifier are added, and the yttrium oxide content in the yttrium-stabilized zirconium powder is the same as the yttrium oxide content in the yttrium phosphate powder in Example 1, the bulk density of the sintered sample is low, the foaming index of the high-alkali glass at 1300° C. is high, and the sample also has zircon decomposition at 1050° C. It is speculated that the zirconium phosphate and yttrium phosphate products formed by the yttrium-stabilized zirconium powder and phosphoric acid solution at high temperature have no effect on inhibiting the decomposition of zircon.

Claims

1. A zircon composite material resistant to high-alkali glass corrosion, characterized in that: The invention comprises the following components in percentage by mass, wherein the total mass of the components except the organic binder is 100%, and the organic binder is calculated as the percentage of the total mass of the remaining components: zircon powder 94.2-99%, yttrium phosphate powder 0.25-4.3%, modifier 0.15-1%, sintering promoter 0.2-0.6%, organic binder 0.1-0.5%; wherein the modifier is aluminum dihydrogen phosphate powder or phosphoric acid solution.

2. The zircon composite material resistant to high-alkali glass corrosion according to claim 1, characterized in that: In the zircon powder, Al2O3<0.35wt.%, Fe2O3<0.15wt.%, TiO2<0.15wt.%, SiO2>32.7wt.%, and ZrO2>65.5wt.%.

3. The zircon composite material resistant to high-alkali glass corrosion according to claim 1, characterized in that: In the yttrium phosphate powder, YPO4≥99.99wt.%, and the crystal form is xenotime.

4. The zircon composite material resistant to high-alkali glass corrosion according to claim 1, characterized in that: The concentration of the phosphoric acid solution is 85 wt.%.

5. The zircon composite material resistant to high-alkali glass corrosion according to claim 1, characterized in that: The sintering promoting agent is titanium oxide powder, wherein TiO2>98.5wt.%, and the crystal form is rutile.

6. The zircon composite material resistant to high-alkali glass corrosion according to claim 1, characterized in that: The organic binder is polyvinyl alcohol.

7. The method for preparing the zircon composite material resistant to high-alkali glass corrosion according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Mix the components to prepare a batch; S2: wet grinding and spray granulation of the batch materials to form granulated powder, and isostatic pressing the granulated powder to obtain a green body; S3: Sintering the green body to obtain a zircon composite material resistant to high-alkali glass corrosion.

8. The method for preparing the zircon composite material resistant to high-alkali glass corrosion according to claim 7, characterized in that: In step S2, the isostatic pressing pressure is 80-180 MPa.

9. The method for preparing the zircon composite material resistant to high-alkali glass corrosion according to claim 7, characterized in that: In step S2, in the slurry obtained after wet grinding, the median diameter of the particles is 4-9 μm.

10. The method for preparing the zircon composite material resistant to high-alkali glass corrosion according to claim 7, characterized in that: In step S3, the sintering temperature is 1510-1580°C.

Images