1. Preparation of spherical strontium carbonate
The methods for preparing high-purity Strontium Carbonate Powder can be divided into strontium chloride method, strontium nitrate method and strontium hydroxide method. The existing preparation research of spherical Strontium Carbonate Powder is based on these three preparation methods, directly or indirectly using strontium chloride, strontium nitrate and recrystallized strontium hydroxide with higher purity as raw materials, while controlling the influence of crystal growth shape. Various factors of morphology were used to obtain spherical Strontium Carbonate Powder.
1.1 Strontium chloride method
The strontium chloride method takes industrial strontium carbonate as raw material, and obtains higher purity strontium chloride through hydrochloric acid dissolution, chemical impurity removal, etc. Wait for the reaction to obtain Strontium Carbonate Powder slurry, and then dehydrate, wash, dry and pulverize to obtain high-purity strontium carbonate product. Although the purity of Strontium Carbonate Powder directly obtained by this method can meet the requirements, the microscopic morphology is irregular and cannot be used for the production of high-quality electronic components. The spherical Strontium Carbonate Powder was prepared by methods such as auxiliary and post-hydrothermal modification.
1.2 Strontium nitrate method
The strontium nitrate method uses industrial Strontium Carbonate Powder as raw material, and obtains high-purity strontium nitrate through processes such as nitric acid dissolution and chemical impurity removal, or directly uses high-purity strontium nitrate as raw material, reacts with ammonium bicarbonate, ammonium carbonate or sodium carbonate to obtain carbonic acid The strontium slurry is dehydrated, washed, dried and pulverized to obtain a high-purity Strontium Carbonate Powder product. The strontium carbonate products obtained by this method also have irregular morphology, which cannot meet the requirements of electronic components for the morphology. Therefore, some researchers have prepared spherical Strontium Carbonate Powder particles by microemulsion method, special reactor, and adding morphology agent control.
1.3 Strontium hydroxide method
The strontium hydroxide method uses industrial Strontium Carbonate Powder as raw material to obtain strontium hydroxide with higher purity through acid-dissolved alkali precipitation or calcination, water leaching, recrystallization and other processes, or directly uses high-purity strontium hydroxide as raw material and reacts with ammonium carbonate or carbon dioxide, etc. A strontium carbonate slurry is obtained, which is then dehydrated, washed, dried and pulverized to obtain a high-purity Strontium Carbonate Powder product. The purity of the product obtained by this method can meet the requirements, but the morphology is irregular, and it cannot be used for the production of electronic components. Therefore, some studies have obtained spherical strontium carbonate products by adding morphology control agents and special reactors.
2. Preparation of Strontium Carbonate Powder composite photocatalyst
2.1 Preparation of Sr(OH)2
Weigh a certain amount of SrCl2 6H2O and NaOH (molar ratio of 1:2) into a beaker, add an appropriate amount of deionized water, and continue to stir at room temperature for 0.5 h to make them evenly mixed. After sufficient reaction, suction filtration to obtain The precipitate was washed several times with deionized water to remove unreacted reagents, then the precipitate was placed in a 100 °C oven, taken out after 3 h, and the obtained sample was labeled as Sr(OH) 2 .
2.2 Preparation of SrCO3 complexes
The dry sample Sr(OH) 2 prepared in the above experimental process was put into a muffle furnace and calcined at 500, 600, 700 and 800 °C for 6 h, respectively. After each calcination, let it cool to room temperature naturally, take out the samples, grind them evenly, and store them in a desiccator for later use. The obtained powder samples are marked as 500, 600, 700 and 800 °C, respectively.