Zirconium dioxide (ZrO2) is an important inorganic chemical raw material with excellent physical and chemical properties, such as high temperature stability, corrosion resistance, low coefficient of thermal expansion and high refractive index. Therefore, zirconium dioxide has been widely used in ceramics, catalysts, fuel cells, biomedicine and other fields. In this paper, the manufacturing method of zirconium dioxide will be introduced.
I. Raw material preparation
The raw material for manufacturing zirconium dioxide is mainly zirconia (ZrSiO4), in which the content of zirconium is about 67.2%. In order to obtain high purity zirconium dioxide, it is necessary to use zircon with low impurity content. In addition, chemical raw materials such as sodium hydroxide and hydrochloric acid need to be prepared.
II. Alkali fusion method
Alkali fusion method is one of the main methods for manufacturing zirconium dioxide. The method is to melt zircon with sodium hydroxide at high temperature to produce sodium zirconate (Na2ZrO3), and then dissolve the sodium zirconate with water to obtain zirconate solution. The specific steps are as follows:
1. Mix zircon and sodium hydroxide in a certain proportion, put into a high temperature furnace, and melt at 1400-1500°C for 2-4 hours.
2. After cooling the melt, dissolve it with water to obtain sodium zirconate solution. Meanwhile, insoluble impurities such as silicates and titanates are filtered out.
3. Hydrochloric acid is added to the sodium zirconate solution to react to form zirconium dioxide precipitate.
4. The zirconium dioxide precipitate is washed, filtered and dried to obtain a high purity zirconium dioxide product.
Third, acid digestion method
Acid digestion method is a relatively simple method of manufacturing zirconium dioxide. The method is to react zirconia with hydrochloric acid to generate zirconium chloride (ZrCl4), and then hydrolyze the zirconium chloride to get zirconium dioxide. The specific steps are as follows:
1. Mix zirconium quartz with hydrochloric acid in a certain proportion and react under heating conditions to produce zirconium chloride and silicic acid.
2. Filter the reaction solution to remove insoluble silicate impurities and obtain zirconium chloride solution.
3. The zirconium chloride solution is hydrolyzed to obtain a zirconium dioxide precipitate. The method of hydrolysis may be to add an alkaline absorbent such as ammonia or sodium hydroxide to the solution so that it reacts with the zirconium chloride to produce zirconium dioxide precipitate.
4. The zirconium dioxide precipitate is washed, filtered and dried to obtain a high purity zirconium dioxide product.
4. Other methods
In addition to the alkali fusion method and acid digestion method, there are some other methods of manufacturing zirconium dioxide, such as the sol-gel method, microwave method and so on. Each of these methods has its own advantages and disadvantages, and you can choose the suitable method according to the specific needs and conditions.
In conclusion, zirconium dioxide is an important inorganic chemical raw material with a wide range of applications. Different manufacturing methods have different advantages and disadvantages and scope of application, and the suitable method can be selected according to specific needs and conditions.
