Yuan Lei's Little Knowledge | Synthesis Method of Lip Powder
lithopone, also known as lithopone, is a white powder that is a mixture of zinc sulfide and barium sulfate. Relative density 4.136-4.39. Insoluble in water, easy to decompose in case of acid to produce hydrogen sulfide gas. It does not react with hydrogen sulfide and alkali. It has good heat resistance, can improve weather resistance, algae resistance, reduce cost and whiteness with excellent hiding power. It is easy to oxidize in the air and agglomerate after being affected with moisture. Whiteness, strong hiding power. The more zinc sulfide, the stronger the hiding power and the higher the quality. The precipitate obtained by the reaction of zinc sulfate and barium sulfide solution is filtered, dried and crushed, then calcined to red heat, poured into water and quenched. The hiding power is inferior to titanium white, and it is not resistant to concentrated sulfuric acid. The following is a small braid with everyone to understand the synthesis method of lide powder.
Natural barite containing more than 95% barium sulfate and anthracite are mixed and fed at a ratio of 3:1, crushed to a diameter of about 2cm or less into a reduction furnace. The temperature of the furnace is controlled to be 1000~1200 ℃ in the front section and 500~600 ℃ in the back section. The reduction furnace rotates at a speed of 80s per revolution, and the reaction conversion rate is 80% ~ 90%. The prepared barium sulfide enters the leacher, and the temperature is controlled to be above 65 ℃, the obtained barium sulfide content is 701, and then enters the clarification tank. After clarification, zinc sulfate is added for reaction, and the zinc sulfate content is controlled to be greater than 28%, pH = 8-9, and a mixture of barium sulfate and zinc sulfide with a density of 1.296-1.357g/cm3 is obtained.
The reaction solution is filtered by plate and frame pressure to obtain a cake-like rider powder with a water content of not more than 45%, enters a drying roaster and roasts to change the crystal form of the rider powder, and then pickled with sulfuric acid at a temperature of 80°C. Finally, it is washed with water, added fixing agent, pressed filter, dried and pulverized.
The calcined product prepared by ordinary lithopone is made into slurry by beating, and then treated with sodium silicate, aluminum sulfate or sodium aluminate and surfactant, and then filtered, washed with water, dried and crushed.
Method, lide, reaction, drying, entering, barium sulfate, pulverization, barium sulfide, covering power, control
The difference between barium sulfate（BaSO4） and barium sulfite（BaSO3）
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.