Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Method for preparing anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum
The invention discloses a method for preparing anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum, which comprises the following steps of: mixing industrial solid waste gypsum serving as a raw material with a hydrochloric acid solution to prepare slurry, adding a certain amount of organic solvent, and reacting at normal pressure and mild temperature to prepare anhydrous calcium sulfate and calcium sulfate dihydrate. After treating for a period of time, separating a solid-liquid mixture, returning the obtained filtrate to continuously react with the waste gypsum, and washing a filter cake to obtain the high-purity anhydrous calcium sulfate. The prepared anhydrous calcium sulfate and a sodium chloride solution are prepared into slurry, and a trace amount of calcium sulfate dihydrate is added as a seed crystal, so that the calcium sulfate dihydrate can be prepared under the condition of room temperature or lower than room temperature. The reaction mother liquor can be recycled for many times. According to the method disclosed by the invention, the industrial solid waste gypsum with relatively high impurity content can be enriched and removed in the process without high temperature (not exceeding 100 DEG C). The prepared anhydrous gypsum has the excellent properties of high purity, high whiteness, uniform particle size and the like. The dihydrate gypsum prepared from the anhydrous gypsum also has the above characteristics. The process is low in energy consumption, does not generate secondary pollution, and is beneficial to large-scale production. The method can realize the purpose of preparing high-quality anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum, finds a substitution technology for increasingly reduced high-grade gypsum resources, and has good economic benefits and wide industrial application prospects.
本发明公开了一种工业固废石膏制备无水硫酸钙和二水硫酸钙的方法，以工业固废石膏为原料，通过将一种工业固废石膏与盐酸溶液混合制浆，并加入一定量有机溶剂，在常压及温和的温度状态下，处理一段时间反应结束后将固液混合物分离，所得滤液可返回继续与废石膏反应，滤饼经洗涤后即可得到高纯无水硫酸钙。将所制备得到的无水硫酸钙与氯化钠溶液配浆，并加入微量的二水硫酸钙做晶种，可实现在室温或低于室温的条件下，制备得到二水硫酸钙。反应母液可多次循环使用。本发明在无需高温的条件下(不超过100℃)即可实现将杂质含量较高的工业固废石膏，在这一过程中杂质得以富集而去除。制备得到的无水石膏具有纯度高，白度高，粒径均匀等优异性能。由无水石膏制备得到的二水石膏同样具有上述特性。本发明工艺能耗低，不产生二次污染，利于规模化生产。可实现由工业固废石膏制备高品质无水硫酸钙和二水硫酸钙的目的，为日益减少的高品位石膏资源找到了替代技术，具有良好的经济效益和广阔的工业化应用前景。
Method for preparing anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum
The invention discloses a method for preparing anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum, which comprises the following steps of: mixing industrial solid waste gypsum serving as a raw material with a hydrochloric acid solution to prepare slurry, adding a certain amount of organic solvent, and reacting at normal pressure and mild temperature to prepare anhydrous calcium sulfate and calcium sulfate dihydrate. After treating for a period of time, separating a solid-liquid mixture, returning the obtained filtrate to continuously react with the waste gypsum, and washing a filter cake to obtain the high-purity anhydrous calcium sulfate. The prepared anhydrous calcium sulfate and a sodium chloride solution are prepared into slurry, and a trace amount of calcium sulfate dihydrate is added as a seed crystal, so that the calcium sulfate dihydrate can be prepared under the condition of room temperature or lower than room temperature. The reaction mother liquor can be recycled for many times. According to the method disclosed by the invention, the industrial solid waste gypsum with relatively high impurity content can be enriched and removed in the process without high temperature (not exceeding 100 DEG C). The prepared anhydrous gypsum has the excellent properties of high purity, high whiteness, uniform particle size and the like. The dihydrate gypsum prepared from the anhydrous gypsum also has the above characteristics. The process is low in energy consumption, does not generate secondary pollution, and is beneficial to large-scale production. The method can realize the purpose of preparing high-quality anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum, finds a substitution technology for increasingly reduced high-grade gypsum resources, and has good economic benefits and wide industrial application prospects.
本发明公开了一种工业固废石膏制备无水硫酸钙和二水硫酸钙的方法，以工业固废石膏为原料，通过将一种工业固废石膏与盐酸溶液混合制浆，并加入一定量有机溶剂，在常压及温和的温度状态下，处理一段时间反应结束后将固液混合物分离，所得滤液可返回继续与废石膏反应，滤饼经洗涤后即可得到高纯无水硫酸钙。将所制备得到的无水硫酸钙与氯化钠溶液配浆，并加入微量的二水硫酸钙做晶种，可实现在室温或低于室温的条件下，制备得到二水硫酸钙。反应母液可多次循环使用。本发明在无需高温的条件下(不超过100℃)即可实现将杂质含量较高的工业固废石膏，在这一过程中杂质得以富集而去除。制备得到的无水石膏具有纯度高，白度高，粒径均匀等优异性能。由无水石膏制备得到的二水石膏同样具有上述特性。本发明工艺能耗低，不产生二次污染，利于规模化生产。可实现由工业固废石膏制备高品质无水硫酸钙和二水硫酸钙的目的，为日益减少的高品位石膏资源找到了替代技术，具有良好的经济效益和广阔的工业化应用前景。
Method for preparing anhydrous calcium sulfate and calcium sulfate dihydrate from industrial solid waste gypsum
一种工业固废石膏制备无水硫酸钙和二水硫酸钙的方法
ZHANG ANJIANG (Autor:in) / YANG LUFENG (Autor:in) / YU JINHAI (Autor:in)
24.01.2023
Patent
Elektronische Ressource
Chinesisch
Method for preparing anhydrous calcium sulfate by pretreating industrial byproduct gypsum
| Europäisches Patentamt | 2024
System for preparing anhydrous calcium sulfate by calcining gypsum
| Europäisches Patentamt | 2023
Method for preparing anhydrous calcium sulfate powder from phosphogypsum
| Europäisches Patentamt | 2024
METHOD FOR PREPARING A HARDENED CALCIUM SULFATE DIHYDRATE BLOCK
| Europäisches Patentamt | 2021
Calcium sulfate gypsum and preparation method thereof
| Europäisches Patentamt | 2020