Manufacturing Method of Sodium Nitrate
Sodium nitrate is an important inorganic chemical raw material, which is widely used in fertilizers, gunpowder, glass, dyestuff and other fields. In this article, we will introduce the manufacturing methods of sodium nitrate, including neutralization method, conversion method and ion exchange method.
I. Neutralization method
Neutralization method is one of the main methods to produce sodium nitrate, and its principle is to neutralize sodium hydroxide or sodium carbonate with nitric acid to produce sodium nitrate and water. The specific steps are as follows:
1. Add sodium hydroxide or sodium carbonate with water to form a certain concentration of solution.
2. Add nitric acid to the solution, control the reaction temperature at 50-60°C, and stir to make the reaction proceed fully.
3. After the reaction is completed, filter to remove impurities and obtain sodium nitrate solution.
4. The sodium nitrate solution is evaporated and concentrated, cooled and crystallized, centrifuged and separated, and dried to obtain the finished product of sodium nitrate.
The production process of the neutralization method is simple and easy to operate, but it should be noted that the pH and temperature of the solution need to be controlled during the reaction process to ensure product quality and yield. In addition, the wastewater produced by this method contains nitric acid and sodium salts, which need to be treated to meet the environmental requirements.
II. Conversion method
The conversion method is to produce sodium nitrate by converting ammonium nitrate into sodium nitrate. The specific steps are as follows:
1. Ammonium nitrate is prepared into a solution of certain concentration by adding water.
2. Add an appropriate amount of sodium hydroxide or sodium carbonate to the solution, so that the ammonium ions in the solution are converted to sodium ions and sodium nitrate is produced at the same time.
3. After the reaction is complete, filter to remove impurities and obtain sodium nitrate solution.
4. The sodium nitrate solution is evaporated and concentrated, cooled and crystallized, centrifuged and separated, and dried to obtain the finished sodium nitrate product.
The advantage of the conversion method is that it can utilize the waste materials in the production process of ammonium nitrate, reduce environmental pollution, and at the same time, it can reduce the production cost. However, the method needs to control the reaction conditions and the amount of alkali added to ensure product quality and yield.
Third, ion exchange method
Ion exchange method is to use the ions in the ion exchange agent to exchange with the ions in the solution, so as to achieve the purpose of separation and purification. In the manufacture of sodium nitrate, ion exchange method can be used to separate sodium nitrate from mixed salt solution. The specific steps are as follows:
1. The mixed salt solution is passed through an exchange column equipped with a cationic exchanger, and the cations in the solution (e.g., Na+) are exchanged with the H+ in the exchanger to produce nitric acid and the corresponding metal salt.
2. The resulting nitric acid solution is mixed with an appropriate amount of sodium hydroxide solution so that the nitric acid reacts with the sodium hydroxide to form sodium nitrate and water.
3. Through the steps of evaporation and concentration, cooling and crystallization, centrifugal separation and drying, the finished product of sodium nitrate is obtained.
The ion exchange method has the advantages of easy operation, high product purity and good environmental protection, but the regeneration and consumption of ion exchangers require certain costs and maintenance.
In summary, there are various manufacturing methods of sodium nitrate, and each method has its advantages and disadvantages and scope of application. In the actual production, the suitable manufacturing method should be selected according to the raw material source, product quality requirements, environmental protection requirements and production costs. Meanwhile, in order to ensure product quality and yield, the production process and operating conditions need to be strictly controlled.
