Gypsum powder is a natural limestone, primarily composed of CaCO3, which is calcined at high temperatures to form quicklime (CaO). After refining and partial digestion, the main component becomes Ca(OH)2. It is then finely milled into a clean, white powder using a high-speed air classification hammer mill.
Gypsum powder applications:
The application is in construction, such as bricklaying, wall painting, etc. However, with the continuous recognition and acceptance of the use of calcium sulfate powder, it is widely used in industries such as industry, agriculture, construction, manufacturing, and food. Specific application industries include: putty powder, latex paint, thermal insulation mortar, architectural coatings, electrical wires and cables, plastic steel doors and windows, and is also used in flue gas desulfurization, wastewater treatment, and more.
Due to the fact that gray calcium powder can impart excellent performance to coatings at a lower cost, it has been used in synthetic resin emulsion coatings in recent years, meeting the requirements of GB/T 9756-2001 and GB 18582-2001 at reduced costs. Additionally, the state, leveling properties, and tactile feel of the coatings in their containers are all favorable. Therefore, under the new standards, gray calcium powder still holds value. However, there is still a possibility of the coating yellowing when applied over old coatings, so its benefits should not be overstated and should be limited to medium and low-grade interior coatings.
Gray calcium powder production process:
The traditional lime production process involves layering limestone and fuel (wood) and then firing it to produce lime. Modern methods utilize mechanized and semi-mechanized kilns, as well as rotary kilns and fluidized bed furnaces, to manufacture lime. The firing time has also been shortened, with the production of lime via a rotary kiln taking only 2 to 4 hours, which can increase production efficiency by over five times compared to vertical kilns. In recent years, energy-saving technologies and equipment such as cross-flow, double inclined slope, oil-fired circular kilns, and short rotary kilns with preheaters have emerged, showing significant energy savings. The fuel sources have also expanded to include coal, coke, heavy oil, or liquefied gas.
