CN113999026A

CN113999026A - Quartz water gap and preparation process thereof

Info

Publication number: CN113999026A
Application number: CN202111340368.9A
Authority: CN
Inventors: 李健; 刘丽丽; 高源�
Original assignee: Yantai Hejing Ceramic New Materials Co ltd
Current assignee: Yantai Hejing Ceramic New Materials Co ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2022-02-01

Abstract

The invention relates to a quartz nozzle and a preparation process thereof, and the preparation process comprises the following steps: preparing quartz slurry, adding inorganic fibers, forming a quartz nozzle blank, demolding, finishing, maintaining and sintering at high temperature; wherein, the adding time of the inorganic fiber is in the final stirring stage or the bubble removing stage, and the inorganic fiber is slowly and uniformly added into the slurry in a vibration feeding mode until the inorganic fiber is uniformly stirred. The quartz nozzle provided by the invention has obvious advantages in the aspects of compressive strength, density, elastic modulus and thermal shock resistance, the service life of the quartz nozzle is obviously prolonged, and the quartz nozzle has important significance in reducing cost and improving production benefit of enterprises.

Description

Quartz water gap and preparation process thereof

Technical Field

The invention relates to the technical field of ceramics, in particular to a quartz nozzle and a preparation process thereof.

Background

The nozzle is an important part used in the steel casting process and mainly plays roles of conveying molten steel, preventing secondary oxidation, flow scattering and splashing of the molten steel, adjusting the flowing state of molten steel in a crystallizer, preventing non-metallic inclusions from being mixed into a casting blank and the like. In the process of steel continuous casting, the quality of a water gap not only directly influences the quality and the yield of a continuous casting slab, but also relates to the labor intensity of continuous casting operators. The water gaps used at present are mostly aluminum carbon and fused silica materials. The aluminum-carbon water gap uses corundum and graphite as raw materials, needs to be preheated when in use, and is easy to have cracks. The quartz nozzle has good thermal shock resistance, higher mechanical strength, good chemical stability and acid slag corrosion resistance, does not need to be baked before use, and has relatively low manufacturing cost. At present, the fused quartz nozzle in China is still produced by the traditional ceramic grouting production process basically, but various problems of excessive sedimentation and over-speed of pouring slurry, uneven firing and the like are very easy to occur in the actual production, so that the manufactured nozzle has insufficient strength, short service life and frequent replacement, the production cost is increased, and the quality of a steel casting product is reduced.

Disclosure of Invention

The invention provides a quartz nozzle and a preparation process thereof, and the quartz nozzle prepared by the process has the advantages of uniformity, high strength, excellent thermal stability and longer service life.

In order to achieve the purpose, the invention provides the following technical scheme: 1. the preparation process of the quartz nozzle is characterized by comprising the following steps of:

the first step is as follows: preparing quartz slurry, namely mixing quartz sand and water according to the ratio of (3-4): 1, putting the mixture into a ball mill for ball milling for 20-30 hours to obtain quartz grinding slurry; directly feeding quartz grinding slurry, quartz sand, a dispersing agent, a ceramic adhesive and inorganic fibers according to the weight ratio of 200: (100-150): 1: (1-2): (40-50) uniformly stirring to obtain quartz slurry.

The second step is that: grouting and molding, namely injecting the quartz slurry into a mold;

the third step: curing, namely performing primary curing on the product mold formed in the second step, demolding after the primary curing, and moving the product mold into a drying chamber for curing for 12-24 hours after demolding to obtain a drying water gap;

the fourth step: firing, namely placing the drying water gap formed in the third step into a sintering kiln, and sintering at 1100-1200 ℃ for 8-10 hours to form a quartz water gap;

wherein in the first step, the adding time of the inorganic fiber is at the end of stirring or at the bubble removing stage; the addition process of the inorganic fiber comprises the following steps: and adding the inorganic fibers into the slurry slowly and uniformly in a vibration feeding mode, and continuously stirring the slurry after the inorganic fibers are added until the inorganic fibers are uniformly stirred.

Preferably, the inorganic fibers are added for a period of time not shorter than one third of the entire stirring period of the silica slurry.

Preferably, in the first step, after the inorganic fibers are added, a dispersion process is performed, wherein the dispersion process is performed by mixing in at least one of an eccentric stirring manner, a planetary stirring manner and a horizontal self-weight mixing manner, and the dispersion process is performed for 30 to 80 minutes.

Preferably, the diameter of the inorganic fiber is 80-200um, and the length is 40-100 mm.

Preferably, the inorganic fiber is at least one of alumina, silicon carbide, silica and carbon.

Preferably, in the third step, the first curing is to place the product mold into a curing room with the temperature of 30-40 ℃ for curing for 24-48 hours.

Preferably, the preparation method further comprises the step of preparing a gel system before the first step, wherein the preparation method comprises the following steps of taking N, N '-dimethylacrylamide as a monomer, N' -methylenebisacrylamide as a cross-linking agent, ammonium persulfate as an initiator, and mixing the components according to the ratio of (20-60): (1-3): (1-2): 400 are prepared into a gel system. In the first step, quartz grinding slurry, quartz sand are directly fed, a gel system, a dispersing agent, a ceramic adhesive and inorganic fibers are mixed according to the weight ratio of 200: (100-150): (30-40): 1: (1-2): (40-50) uniformly stirring to obtain quartz slurry. And in the third step, the first curing comprises a first stage and a second stage, wherein the first stage is to put the product mold into a water bath at 60 ℃ for curing for 20-30 minutes and then remove the mold, and the second stage is to cure the water gap blank after the mold is removed for 24-48 hours at room temperature.

The invention also provides a quartz nozzle which is prepared by using the preparation process of any scheme.

According to the preparation process of the quartz nozzle, the inorganic fibers are added, and the addition processes of adjusting solid content, fiber material quality, fiber length, diameter, addition amount, addition time and the like are combined, so that the inorganic fibers are more uniformly and completely blended into the quartz slurry and are uniformly distributed in the quartz nozzle matrix in a pouring coagulation or slip casting mode.

Detailed Description

Other advantages and features of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is to be understood that the invention is not limited to the specific embodiments disclosed, but is to be construed as limited only by the appended claims. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The first embodiment of the invention provides a preparation process of a quartz nozzle, which comprises the following steps:

the first step is as follows: preparing quartz slurry, namely mixing quartz sand and water according to the ratio of (3-4): 1, putting the mixture into a ball mill filled with ball stones for ball milling for 20-30 hours to obtain quartz grinding slurry, wherein the quartz sand is molten quartz sand with the particle size of 30-50 meshes or 100-200 meshes or 300-400 meshes; directly feeding quartz grinding slurry, quartz sand with the particle size of 300-400 meshes, a dispersing agent, a ceramic adhesive and inorganic fibers according to the weight ratio of 200: (100-150): 1: (1-2): (40-50) uniformly stirring to obtain quartz slurry.

Wherein, the diameter of the inorganic fiber is 80-200um, the length is 40-100mm, can select alumina, carborundum, silicon dioxide, carbon, etc., can select one or more to match and use, its adding opportunity is after ball milling and high-speed stirring stage of the slurry, specifically, should add in the terminal stage of stirring or bubble removal stage, in order to prevent the fiber from being stirred and broken; the inorganic fiber is added in a vibration feeding mode, so that the inorganic fiber is slowly and uniformly added into the slurry at a fixed position, the fixed position is preferably a position relatively far away from the stirring teeth, the adding time is not shorter than one third of the whole stirring time of the quartz slurry, and the stirring is continuously maintained after the inorganic fiber is added until the stirring is uniform.

Further, after the inorganic fibers are added, a dispersion process is needed, and the inorganic fibers are uniformly dispersed in the slurry by adopting at least one of eccentric stirring, planetary stirring and horizontal self-weight mixing for 30-80 minutes.

The second step is that: and (3) grouting and forming, namely injecting the quartz slurry into a gypsum mould, wherein the diameter of an injection interface of the mould is 30-200mm, so that the orderly injection of fibers is facilitated.

The third step: and (4) curing, namely putting the product mold formed in the second step into a curing room at the temperature of 30-40 ℃ for curing for 24-48 hours for primary curing, demolding after the primary curing, moving into a drying room at the temperature of 80 ℃ for curing for 12-24 hours after demolding for secondary curing, and obtaining the drying nozzle.

The fourth step: and firing, namely placing the drying water gap formed in the third step into a sintering kiln, sintering for 8-10 hours at 1100-1200 ℃ to form a quartz water gap, and specifically placing the quartz water gap into a shuttle kiln for primary sintering.

Example two

The second embodiment of the invention provides a preparation process of a quartz nozzle, which comprises the following steps:

the first step is as follows: preparing a gel system, wherein low-toxicity N, N '-dimethylacrylamide is used as a monomer, N' -methylenebisacrylamide is used as a cross-linking agent, ammonium persulfate is used as an initiator, and the gel system is prepared by mixing the following components in percentage by weight (20-60): (1-3): (1-2): 400 are prepared into a gel system.

The second step is that: preparing quartz slurry, namely mixing quartz sand and water according to the ratio of (3-4): 1, putting the mixture into a ball mill filled with ball stones for ball milling for 20-30 hours to obtain quartz grinding slurry, wherein the quartz sand is molten quartz sand with the particle size of 30-50 meshes or 100-200 meshes or 300-400 meshes; directly feeding quartz grinding slurry, quartz sand with the particle size of 300-400 meshes, a gel system, a dispersing agent, a ceramic adhesive and inorganic fibers according to the weight ratio of 200: (100-150): (30-40): 1: (1-2): (40-50) uniformly stirring to obtain quartz slurry.

The third step: and (3) grouting and forming, namely injecting the quartz slurry into a stainless steel mold, wherein the diameter of an injection interface of the mold is 30-200mm, so that the ordered injection of fibers is facilitated.

The fourth step: and (4) curing, namely putting the product mold formed in the third step into a water bath at 60 ℃, curing for 20-30 minutes, then demolding, curing the water gap blank after the mold is removed at room temperature for 24-48 hours, then moving the water gap blank into a drying chamber at 80 ℃ for curing again, and curing for 12-24 hours to obtain the dried water gap.

The fifth step: and firing, namely placing the drying water gap formed in the fourth step into a sintering kiln, sintering at 1100-1200 ℃ for 8-10 hours to form a quartz water gap, and specifically placing the quartz water gap into a shuttle kiln for primary sintering.

Comparative example 1

Compared with the first embodiment, the first embodiment of the present invention is different from the first embodiment in that the method comprises the following steps of:

the first step is as follows: preparing quartz slurry, namely mixing quartz sand and water according to the ratio of (3-4): 1, putting the mixture into a ball mill filled with ball stones for ball milling for 20-30 hours to obtain quartz grinding slurry, wherein the quartz sand is molten quartz sand with the particle size of 30-50 meshes or 100-200 meshes or 300-400 meshes; quartz grinding slurry, quartz sand with the particle size of 300-400 meshes, a dispersing agent and a ceramic adhesive are added according to the proportion of 200: (100-150): 1: (1-2) uniformly stirring in proportion to obtain quartz slurry;

the second step is that: grouting and molding, namely injecting the quartz slurry into a gypsum mold;

the third step: curing, namely placing the product mold formed in the second step into a curing room at the temperature of 30-40 ℃ for curing for 24-48 hours for primary curing, demolding after the primary curing, moving into a drying room at the temperature of 80 ℃ for curing for 12-24 hours after demolding for secondary curing to obtain a drying water gap;

the fourth step: and firing, namely placing the drying water gap formed in the third step into a sintering kiln, sintering for 8-10 hours at 1100-1200 ℃ to form a quartz water gap, and specifically placing the quartz water gap into a shuttle kiln for primary sintering. Comparative example 1

Comparative example No. two

Compared with the first embodiment, the second embodiment of the present invention is different from the first embodiment in that the process of adding inorganic fibers is not included, and comprises the following steps:

the first step is as follows: preparing quartz slurry, namely mixing quartz sand and water according to the ratio of (3-4): 1, putting the mixture into a ball mill filled with ball stones for ball milling for 20-30 hours to obtain quartz grinding slurry, wherein the quartz sand is molten quartz sand with the particle size of 30-50 meshes or 100-200 meshes or 300-400 meshes; directly feeding quartz grinding slurry, quartz sand with the particle size of 300-400 meshes, a dispersing agent, a ceramic adhesive and inorganic fibers according to the weight ratio of 200: (100-150): 1: (1-2): (40-50) are added simultaneously and stirred uniformly to obtain quartz slurry.

Wherein the inorganic fiber has a diameter of 80-200um and a length of 40-100mm, and can be selected from alumina, silicon carbide, silicon dioxide, carbon, etc., and one or more of them can be used in combination.

The quartz nozzles prepared by the processes of the first embodiment and the second embodiment and the first comparative example and the second comparative example are randomly sampled from domestic and imported quartz nozzles on the current market, and are compared and detected in the aspects of volume density, apparent porosity, compressive strength, thermal expansion coefficient and the like, and the detection results are shown in the following table:

according to the above table, as can be seen from the detection results of the first embodiment, the second embodiment and the first comparative example, and the detection results of the commercially available domestic and imported quartz nozzle, the quartz nozzle and the preparation process thereof provided by the invention have obvious advantages in terms of volume density, apparent porosity, compressive strength and thermal expansion coefficient by adding inorganic fibers in raw materials; through the data of the comparative example II, the addition of the inorganic fiber and the addition process of the inorganic fiber related to the invention are combined, and the obtained quartz nozzle product has further improvement in the aspects of volume density, apparent porosity, compressive strength and thermal expansion coefficient.

According to the quartz nozzle and the preparation process thereof provided by the invention, inorganic fibers are added, and the addition processes of adjusting solid phase content, fiber material, fiber length, diameter, addition amount, addition time and the like are combined, so that the inorganic fibers are more uniformly and completely blended into quartz slurry and are uniformly distributed in a quartz nozzle matrix in a pouring coagulation or grouting forming mode. Compared with the existing quartz nozzle, the quartz nozzle toughened by inorganic fibers has obvious advantages in the aspects of breaking strength, density, elastic modulus and thermal vibration resistance, can obviously prolong the service life of the quartz nozzle, and has important significance in reducing cost and improving production benefit of enterprises.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed. The above-described embodiments of the present invention do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The preparation process of the quartz nozzle is characterized by comprising the following steps of:

2. The process for preparing a quartz nozzle as claimed in claim 1, wherein the inorganic fiber is added in the first step for a time not shorter than one third of the time of stirring the whole quartz slurry.

3. The process for preparing a quartz nozzle as claimed in claim 1, wherein in the first step, after the inorganic fiber is added, a dispersion process is performed, wherein the dispersion process is performed by at least one of eccentric stirring, planetary stirring and horizontal self-weight mixing, and the dispersion process is performed for 30-80 minutes.

4. The process for preparing a quartz nozzle as claimed in claim 1, wherein the inorganic fiber has a diameter of 80-200um and a length of 40-100 mm.

5. The process of claim 1, wherein said inorganic fiber is at least one of alumina, silicon carbide, silica, and carbon.

6. The preparation process of a quartz nozzle according to claim 1, characterized in that before the first step, a gel system is further prepared, wherein the preparation steps are that N, N '-dimethylacrylamide is adopted as a monomer, N' -methylenebisacrylamide is adopted as a cross-linking agent, ammonium persulfate is adopted as an initiator, and the ratio of the monomer to the cross-linking agent to the initiator to water is (20-60): (1-3): (1-2): 400 are prepared into a gel system.

7. The preparation process of a quartz nozzle according to claim 6, wherein in the first step, the quartz slurry, the quartz sand direct charge, the gel system, the dispersant, the ceramic adhesive and the inorganic fiber are mixed according to a ratio of 200: (100-150): (30-40): 1: (1-2): (40-50) uniformly stirring to obtain quartz slurry.

8. The process for preparing a quartz nozzle as claimed in claim 7, wherein in the third step, the first curing comprises a first stage and a second stage, the first stage is to put the product mold into a water bath with 60 ℃ for curing for 20-30 minutes and then to remove the mold, and the second stage is to cure the nozzle blank with the removed mold at room temperature for 24-48 hours.

9. The process for preparing a quartz nozzle as claimed in claim 1, wherein in the third step, the first curing is to put the product mold into a curing room at 30-40 ℃ for 24-48 hours.

10. A quartz nozzle, characterized by being produced by the production process according to any one of claims 1 to 9.