Lide powder is an important chemical pigment widely used in plastics, paints, printing inks and other fields. It is a mixture of two compounds, barium sulfate and zinc sulfide, with excellent covering power, weather resistance and chemical stability. In the field of raw materials for chemical production, there are mainly the following manufacturing methods for Lidl powder:
1. Precipitation method
Precipitation method is the main method for producing Lidl powder in China at present. The method is to make the two raw materials of barium sulfate and zinc sulfide into solution separately, then mix them together, and the co-precipitation reaction occurs under the stirring condition to produce Lide powder. The specific operation steps are as follows:
(1) Mix barium sulfate with water in a certain proportion to make barium sulfate suspension.
(2) Mix zinc sulfide with water in a certain proportion to make zinc sulfide solution.
(3) Mix barium sulfate suspension and zinc sulfide solution together, add a certain amount of dispersant and precipitant, stir for a certain period of time, and then leave to precipitate.
(4) The precipitate is washed, dried and pulverized to obtain a Lidl powder product.
The advantages of the precipitation method are simple process, convenient operation and low production cost, but the product size distribution is wide, the color is yellowish and the covering power is relatively low.
2. Hydrothermal method
Hydrothermal method is a method of chemical reaction in high-temperature and high-pressure aqueous solution, which can be used to prepare high-purity, ultra-fine powder materials. In the process of hydrothermal method for the preparation of Lidl powder, a mixed solution of barium sulfate and zinc sulfide is placed in a high-pressure reactor, which is heated and pressurized to react and produce Lidl powder. The specific operation steps are as follows:
(1) Mix barium sulfate and zinc sulfide in a certain proportion, add appropriate amount of water and dispersant to make a mixed solution.
(2) Pour the mixed solution into the high-pressure reactor, seal it and place it in the oven to heat to a certain temperature and keep it for a certain time.
(3) When the reaction is finished, the reactor is cooled to room temperature and opened to remove the product.
(4) The product is washed, dried and pulverized to obtain the Lidl powder product.
The advantages of hydrothermal method are high product purity, narrow particle size distribution, and white color, but the equipment investment is larger and the production cost is higher.
3. Microemulsion method
Microemulsion method is a method of preparing nanomaterials, which can be used to prepare high purity and uniformly dispersed Lidl powder. In this method, a mixed solution of barium sulfate and zinc sulfide is added to a microemulsion formed by a surfactant, through which the reactants are made to mix on a nanoscale to produce uniformly dispersed Lidl powder. The specific operation steps are as follows:
(1) Barium sulfate and zinc sulfide are mixed in a certain proportion to make a mixed solution.
(2) Mix the surfactant, co-surfactant and water in a certain proportion to make a microemulsion.
(3) Add the mixed solution to the microemulsion and stir for a certain period of time to make it fully reacted.
(4) The reaction product is centrifuged and separated, washed, dried and pulverized to obtain the Lidl powder product.
The advantages of the microemulsion method are small particle size, uniform distribution and white color of the product, but the operation is more complicated and the production cost is higher.
In summary, the main manufacturing methods of Lide powder are precipitation method, hydrothermal method and microemulsion method. Different methods have different advantages and disadvantages and scope of application, and the suitable manufacturing method should be selected according to the specific situation. Meanwhile, in order to obtain high-quality products, it is also necessary to strictly control the quality of raw materials, reaction conditions and post-treatment process and other factors.
