Introduction to Gypsum Mine
Gypsum is also called plaster. The gypsum mine is the main raw material to produce gypsum binder and gypsum building products and the retarder of portland cement. After calcining under 600~800°C and adding little catalyst ( such as lime ), we can levigate the whole mixture and get anhydrite binder which is also called Kim Binder. After calcining under 900~1000°C and levigating, we can get calcined gypsum. We can use both the plasters in the production and the strength is higher than the usual building gypsum products. Plaster of paris has better wear resistance and water resistance.In civil engineering, the gypsum mine can be used in Interior plastering, painting, architecture and decoration products and gypsum board. With the development of cement industry and the increase of gypsum requirement, market demand to construction gypsum and gypsum building products has promoted the rapid development of gypsum mining.
Gypsum Mine Application in industry
- Gypsum Application in the construction and building materials Industry : The plaster raw materials mainly include raw gypsum, chemical gypsum, anhydrite. Among these, the gypsum usually refers to natural gypsum, also known as soft plaster and is the main raw material in construction gypsum production. The chemical plaster is often used in Phosphoric acid and phosphate fertilizer production while the anhydrite is usually used to produce construction gypsum products or additives which is different from the raw gypsum mine.
- Gypsum Application in Cement Industry : The grinding plaster can be used as portland cement retarder, cement batching, anhydrite cement production, gypsum slag cement production and gypsum bauxite expansion cement production, etc.
- Gypsum Application in chemical industry : The gypsum can be used to produce sulfuric acid, ammonium sulfate fertilizer, etc.
- Usage in agriculture : For fertilizer, pesticide production and soil improvement, crushed gypsum is widely applied.
- Other uses : What’s more, the grinding plaster can also be used in packing paints, rubber, plastics, textiles, paper, chalk, toothpaste, cosmetics. In food, arts and crafts,etc. gypsum has a wide range of applications.
Case Introduction
Photoelectric separation is a sorting method which uses the light difference between gypsum mine and gangue according to the photoelectric effect principle. When needing high-quality ore dressing, the method of photoelectric separation can be used to purify mineral.
β-plaster production craft flow is usually as follows:
ore storage→crushing and grinding →Homogenization→Calcination and dehydration→Aging→Grinding and mixing→Package. Pay attention that do first grinding before calcine while using wok.Raw gypsum dry calcining process is as follows : After being shipped from the mining site, the raw gypsum mine should be first through storage and selection, and then enter into the follow process to ensure continuous and stable quality feed. From the vibrating feeder to the jaw crusher, the gypsum quarry is feeded and crushed to less than 8cm. Then through the secondary gypsum crushing, such as impact crusher, cone crusher,etc. the mineral is crushed to less than 2cm. The end products will be transported to calcining kiln through bucket elevator. We can chanage the temperature of the calcining kiln to produce β-type hemihydrate gypsum, anhydrite and over gypsum.
α-wet calcining process and the process is generally as follows : Gypsum raw material warehouse→vibrating screen→Autoclave autoclaved and dried→crushing and grinding→Homogenization and storage→ mixing of a-plaster and β-plaster→package and transportation.
