阅读说明：本技术 一种降低电熔氧化锆粉氧化硅含量的方法 (Method for reducing content of silicon oxide in fused zirconia powder ) 是由 初薛基 杨强文 魏爽 卢建华 刘印阁 于 2020-07-22 设计创作，主要内容包括：本发明涉及电熔氧化锆粉提纯技术,特别涉及一种降低电熔氧化锆粉氧化硅含量的方法,所述方法包括以下步骤：步骤1、将氧化硅研磨得电熔氧化锆粉；步骤2、将所得电熔氧化锆粉和降硅酸溶液充分反应得氧化锆浆料；所述降硅酸溶液包括如下质量份的组分：水100份,浓酸5-10份和氟化物2-3份；步骤3、将步骤2所得氧化锆浆料经过滤、洗涤和干燥后,得到低硅电熔氧化锆粉。本发明的有益效果在于：区别于现有技术,本发明方法能够将氧化硅含量0.1％-0.5％的氧化锆提纯至氧化硅含量≤0.05％,使最终的氧化锆粉末纯度更高,品质更加稳定。且生产过程中废气得以回收,降硅酸液可以循环使用,对环境污染小。(The invention relates to a purification technology of electric smelting zirconia powder, in particular to a method for reducing the content of silicon oxide in the electric smelting zirconia powder, which comprises the following steps: step 1, grinding silicon oxide to obtain electric melting zirconia powder; step 2, fully reacting the obtained electric melting zirconia powder with a desilicication solution to obtain zirconia slurry; the silicon reduction acid solution comprises the following components in parts by mass: 100 parts of water, 5-10 parts of concentrated acid and 2-3 parts of fluoride; and 3, filtering, washing and drying the zirconia slurry obtained in the step 2 to obtain the low-silicon electrofusion zirconia powder. The invention has the beneficial effects that: different from the prior art, the method can purify the zirconia with the silicon oxide content of 0.1-0.5% to the silicon oxide content of less than or equal to 0.05%, so that the final zirconia powder has higher purity and more stable quality. And waste gas can be recovered in the production process, the desiliconization acid liquid can be recycled, and the environmental pollution is small.)

1. A method for reducing the content of silicon oxide in fused zirconia powder is characterized by comprising the following steps:

step 1, processing the fused zirconia hollow spheres or particles with the silicon oxide content of 0.1-0.5% into the particle size of below 200 meshes by using crushing and grinding equipment to obtain fused zirconia powder;

step 2, mixing the fused zirconia powder obtained in the step 1 and the desilicication solution according to a mass ratio of 1: (1.5-3), mixing and stirring, and fully reacting to obtain zirconia slurry;

the silicon reduction acid solution comprises the following components in parts by mass: 100 parts of water, 5-10 parts of concentrated acid and 2-3 parts of fluoride;

and 3, filtering, washing and drying the zirconia slurry obtained in the step 2 to obtain the low-silicon electrofusion zirconia powder.

2. A method for reducing the silica content of electrofused zirconia powder according to claim 1, characterized in that the reaction time of step 2 is 0.5-2 hours.

3. The method for reducing the content of silicon oxide in the electrofused zirconia powder according to claim 1, wherein the particle size D50 of the electrofused zirconia powder in the step 1 is controlled to be 5 to 30 μm.

4. The method for reducing the content of fused zirconia powder silica according to claim 1, wherein the concentrated acid is concentrated sulfuric acid, concentrated hydrochloric acid or concentrated nitric acid; the fluoride is hydrogen fluoride, sodium fluoride or potassium fluoride.

5. The method for reducing the content of fused zirconia powder silica according to claim 1, wherein the filtration in step 3 is plate and frame filter pressing or vacuum filtration.

6. The method for reducing the content of silicon oxide in the electrofused zirconia powder according to claim 1, wherein the drying in step 3 is flash drying, spray drying or hot air drying.

7. The method for reducing the content of fused zirconia powder silica according to claim 1, comprising the steps of:

step 1, processing an electric melting zirconia hollow ball or particle with the silicon oxide content of 0.16% into a particle size of 1000 meshes by using crushing and grinding equipment to obtain electric melting zirconia powder;

step 2, mixing the fused zirconia powder obtained in the step 1 and the desilicication solution according to a mass ratio of 1: 2, mixing and stirring the mixture, and fully reacting for 1 hour to obtain zirconia slurry;

the silicon reduction acid solution comprises the following components in parts by weight: 100 parts of water, 5 parts of concentrated hydrochloric acid and 2 parts of hydrofluoric acid;

step 3, filtering the zirconia slurry obtained in the step 2 by using a plate-and-frame filter press, and washing for 3 times; drying by a hot air drying box; obtaining the low-silicon electric melting zirconia powder.

Technical Field

The invention relates to a purification technology of electric melting zirconia powder, in particular to a method for reducing the content of silicon oxide in the electric melting zirconia powder.

Background

The industrial production of zirconia is widely applied to the fields of refractory materials, ceramic color glaze materials, sponge zirconium and the like, and the main production methods comprise a chemical method and an electric melting method. The electric melting method is characterized in that a zircon sand raw material and a carbon reducing agent are subjected to desiliconization treatment at high temperature in an electric arc furnace, then a zirconium oxide solution is formed by compressed air blowing or casting to obtain an electric melting zirconium oxide product, and then particles or powder with proper granularity requirements are obtained by subsequent finish machining treatment and are applied to related fields.

In the process of producing zirconia by an electric melting method, whether desiliconization completely determines the content of silicon oxide in an electric melting zirconia product, and the lower the content of silicon oxide is, the higher the grade of zirconium oxide is according to different grades of zirconium oxide with different contents of silicon oxide. The content of silicon oxide in the zirconia powder by the electric melting method is usually between 0.1 and 0.5 percent, the difficulty of enabling the content of the silicon oxide to reach within 0.1 percent by only electric melting desiliconization is very large, and the production is extremely unstable.

The content of the silicon oxide in the electric melting zirconia influences the service performance of the refractory material, and also has certain influence on the color development performance of ceramic color glaze, and in the production of ceramic products, the existence of the silicon oxide is easy to generate a glass phase, thereby influencing the appearance and the service performance of products. In the production of commercial zirconium sponge, although the silica will eventually be SiCl₄The amount of SiCl is greatly reduced if the silica content in the zirconia is low₄The production is more energy-saving and environment-friendly in production.

Disclosure of Invention

In order to overcome the defects of the prior art, the technical problems to be solved by the invention are as follows: provides a method for reducing the content of silicon oxide in fused zirconia powder.

In order to solve the technical problems, the invention adopts the technical scheme that: the method for reducing the content of silicon oxide in the fused zirconia powder comprises the following steps:

step 1, processing the fused zirconia hollow spheres or particles with the silicon oxide content of 0.1-0.5% into the particle size of below 200 meshes by using crushing and grinding equipment to obtain fused zirconia powder;

step 2, mixing the fused zirconia powder obtained in the step 1 and the desilicication solution according to a mass ratio of 1: (1.5-3), mixing and stirring, and fully reacting to obtain zirconia slurry;

the silicon reduction acid solution comprises the following components in parts by weight: 100 parts of water, 5-10 parts of concentrated acid and 2-3 parts of fluoride;

and 3, filtering, washing and drying the zirconia slurry obtained in the step 2 to obtain the low-silicon electrofusion zirconia powder.

Preferably, in the method for reducing the content of fused zirconia powder silica, the reaction time in step 2 is 0.5 to 2 hours.

Preferably, in the method for reducing the content of silicon oxide in the fused zirconia powder, the particle size D50 of the fused zirconia powder in the step 1 is controlled to be 5-30 μm.

Preferably, in the above method for reducing the content of fused zirconia powder silica, the concentrated acid is concentrated sulfuric acid, concentrated hydrochloric acid or concentrated nitric acid; the fluoride is hydrogen fluoride, sodium fluoride or potassium fluoride.

Preferably, in the above method for reducing the content of fused zirconia powder silica, the filtration in step 3 is plate-and-frame filter pressing or vacuum filtration.

Preferably, in the above method for reducing the content of fused zirconia powder silica, the drying in step 3 is flash drying, spray drying or hot air drying.

Preferably, the method for reducing the content of the fused zirconia powder silicon oxide specifically comprises the following steps:

step 1, processing an electric melting zirconia hollow ball or particle with the silicon oxide content of 0.16% into a particle size of 1000 meshes by using crushing and grinding equipment to obtain electric melting zirconia powder;

step 2, mixing the fused zirconia powder obtained in the step 1 and the desilicication solution according to a mass ratio of 1: 2, mixing and stirring the mixture, and fully reacting for 1 hour to obtain zirconia slurry;

the silicon reduction acid solution comprises the following components in parts by weight: 100 parts of water, 5 parts of concentrated hydrochloric acid and 2 parts of hydrofluoric acid;

step 3, filtering the zirconia slurry obtained in the step 2 by using a plate-and-frame filter press, and washing for 3 times; drying by a hot air drying box; obtaining the low-silicon electric melting zirconia.

The invention has the beneficial effects that: different from the prior art, the invention provides a method for removing silicon oxide in fused zirconia by a wet method, which can purify zirconia with the silicon oxide content of 0.1-0.5% until the silicon oxide content is less than or equal to 0.05%, so that the final zirconia powder has higher purity and more stable quality. In the method, when the electric melting zirconia powder and the desiliconization acid solution react, free silica reacts with fluoride ions to generate silicon tetrafluoride gas to be discharged, the gas is absorbed by liquid alkali, waste gas in the production process is recovered, and the desiliconization acid solution can be recycled and has little pollution to the environment.

Detailed Description

In order to explain the technical content, the objects and the effects of the present invention in detail, the following description will be given with reference to the embodiments.

The invention provides a method for reducing the content of silicon oxide in fused zirconia powder, which comprises the following steps:

1. the fused zirconia hollow spheres or particles with the silicon oxide content of 0.1-0.5 percent are processed into 200 meshes with fine granularity by crushing and grinding equipment.

The method for detecting the content of the silicon oxide comprises the following steps: GB T21114-2007 refractory material X-ray fluorescence spectrochemistry analysis fusion-cast glass flake method.

2. Preparing a silicic acid reducing solution, wherein the formula is as follows: 100 parts of water, 5-10 parts of concentrated acid and 2-3 parts of fluoride, and fully stirring the mixture to ensure that no insoluble substance exists for later use. The parts of the formula refer to parts by mass; the concentrated acid comprises concentrated sulfuric acid (mass fraction is more than or equal to 92%), concentrated hydrochloric acid, concentrated nitric acid and other strong acids; the fluoride comprises soluble fluorides such as hydrogen fluoride (mass fraction is more than or equal to 40%), sodium fluoride, potassium fluoride and the like;

3. mixing the fused zirconia powder and the desilicication solution according to the mass ratio of 1: (1.5-3), mixing and stirring, and fully reacting for 0.5-2 hours.

The reaction mechanism is that under the acidic condition, free silicon oxide reacts with fluorine ions to generate silicon tetrafluoride gas to be discharged, and the equation of the reaction ions is as follows: SiO 2₂+4F^-+4H⁺—SiF_4(q)+2H₂O；SiF₄The gas is absorbed by liquid alkali, and the reaction equation is as follows: SiF₄+6NaOH—Na₂SiO₃+4NaF+3H₂O。

4. Filtering, washing and drying the zirconia slurry treated by the silicic acid reducing solution to obtain SiO₂Low silicon electric melting zirconia powder with the content less than or equal to 0.05 percent.

The filtering mode can select plate-and-frame filter pressing, vacuum filtering and the like;

the drying can be performed by flash drying, spray drying, hot air drying, etc.;

compared with the prior art, the method for reducing the content of the silicon oxide in the fused zirconia powder provides a method for removing the silicon oxide in the fused zirconia by a wet method, and the method can purify the zirconia with the silicon oxide content of 0.1-0.5% until the silicon oxide content is less than or equal to 0.05%, so that the final zirconia powder has higher purity and more stable quality. And waste gas can be recovered in the production process, the desiliconization acid liquid can be recycled, and the environmental pollution is small.