Gypsum powder is the main raw material of gypsum board production line. Many people are not clear about the comparison between gypsum powder and lime powder. Both can be solidified to form a board. Why do you choose gypsum to make gypsum board instead of lime powder to make lime board?
Gypsum is a monoclinic mineral, which is a hydrate of calcium sulfate (CaSO4). Gypsum is a widely used industrial and building material. It can be used for cement retarder, gypsum building products, model production, medical food additives, sulfuric acid production, paper filler, paint filler, etc.
Lime is a kind of air-hardened inorganic cementing material with calcium oxide as the main component. Lime is made from limestone, dolomite, chalk, shell and other products with high calcium carbonate content and calcined at 900~1100 ℃. Lime is an early cementing material used by human beings. Lime is widely used in civil engineering and can also be used in medicine in China.
Gypsum is a monoclinic mineral, and its main chemical component is calcium sulfate (CaSO4). Gypsum is a widely used industrial and building material. It can be used for cement retarder, gypsum building products, model production, medical food additives, sulfuric acid production, paper filler, paint filler, etc.
One industry in which gypsum is widely used is construction products, such as some paper gypsum boards, fiber gypsum boards, decorative gypsum boards, etc.
quick lime
Calcium oxide (alias, quicklime, lime), white (or gray, brownish white) in shape, amorphous, absorbs water and carbon dioxide in the air. Calcium oxide reacts with water to form calcium hydroxide and release heat. Soluble in acid water, insoluble in alcohol. It is an inorganic alkaline corrosion article with the national hazard code of 95006.
It is used for steel, pesticide, medicine, desiccant, tanning and alcohol dehydration. Quicklime generally contains superheated lime, which is slow to ripen. If it is ripened again after the lime slurry is hardened, it will cause swelling and cracking due to the expansion caused by ripening.
It is especially suitable for local specialties such as puffed food, mushroom and agaric, as well as products of instruments, medicine, clothing, electronics and telecommunications, leather, textile and other industries.
Hydrated lime
Calcium hydroxide is a white powder solid. Also known as hydrated lime and hydrated lime. Calcium hydroxide is a kind of strong alkali with the general property of alkali. The alkalinity of calcium hydroxide is stronger than that of sodium hydroxide (metal activity: calcium ＞ sodium), but the solubility of calcium hydroxide is much smaller than that of sodium hydroxide, so the corrosivity and alkalinity of calcium hydroxide solution is smaller than that of sodium hydroxide. These properties determine the wide application of calcium hydroxide.
Difference between gypsum and lime
Gypsum paste is dried due to the reaction with water, which makes the water react away, so the speed is relatively fast. However, lime solidification and hardening include two simultaneous processes of drying, crystallization and carbonization, which are relatively complex
The lime slurry is dried due to evaporation or absorption of water. Capillary pressure is generated in the pore network of the slurry to make the lime particles more compact and obtain strength. This strength is similar to the strength obtained by water loss of clay, which is small and will be lost in case of water. At the same time, due to drying and water loss, the calcium hydroxide solution in the slurry is supersaturated, and calcium hydroxide crystals are crystallized, resulting in strength; However, the number of precipitated crystals is small, and the strength growth is not large. In the atmospheric environment, calcium hydroxide will react with carbon dioxide in the air to generate calcium carbonate in the wet state, and release water, which is carbonization.