The production of gypsum powder is a physical and chemical process that uses calcium sulfate dihydrate as raw material, which is dehydrated and converted into calcium sulfate hemihydrate. The core is to accurately control the dehydration temperature and time to obtain β - or high-strength α - type gypsum powder suitable for building use.
The production process begins with raw material pretreatment. Natural gypsum or industrial by-product desulfurization gypsum needs to be crushed, screened, and dried to ensure that the feed particle size is less than 30 millimeters and the moisture content is less than 15%, laying a uniform foundation for subsequent processes. Subsequently, it enters the grinding and grading stage, where the material is ground to 80-325 mesh using a vertical mill or Raymond mill, and the particle size distribution is precisely controlled by a powder selector to ensure that the final product has good workability and strength development performance.
Calcination and dehydration are the core steps of the process, using equipment such as boiling furnaces, rotary kilns, or frying pans to achieve the conversion of dihydrate gypsum to hemihydrate gypsum within the temperature range of 145-180 ℃. Boiling furnace has become the mainstream choice due to its high thermal efficiency and stable temperature control, especially suitable for the large-scale treatment of desulfurization gypsum. If the temperature is controlled at 120-130 ℃ and supplemented with a crystallization agent, dense α - hemihydrate gypsum with a compressive strength of over 50MPa can be generated, which is suitable for high-strength self leveling mortar and precision molds.
The dehydrated material is cooled to below 60 ℃ by a spiral cooler to prevent crystal transformation, and then sealed for moisture resistance by an automatic packaging machine. The moisture content of the finished product should be controlled within 1.5%. The entire process emphasizes continuity, automation, and waste heat recovery, with a unit energy consumption as low as 45 kWh/ton, which is in line with the policy orientation of the national "14th Five Year Plan" for the high-value utilization of industrial by-product gypsum in the development of circular economy.
In the Linyi area, enterprises generally use desulfurization gypsum as raw material, relying on the advantages of the local building materials industry chain, and prioritizing the use of boiling furnaces and vertical grinding and finishing line equipment equipped with DCS automatic control systems to ensure product stability and environmental compliance. All products leaving the factory must pass CMA certification testing, covering setting time, flexural strength, chloride ion content, and radioactive indicators, and meet national standards such as GB/T 9776-2022 and GB/T 37785-2019.
Linyi Jinhao Machinery is located in Linyi City, Shandong Province. It is a manufacturer mainly engaged in the production, sales, and service of complete sets of gypsum board equipment, gypsum powder equipment, and other mechanical equipment. Address: No. 8, Dongcheng Project Cluster Area, Pingyi County, Linyi City, Shandong Province. Contact Mr. Zhang at 13696392688