公开(公告)号：US08529863B2

公开(公告)日：2013-09-10

申请号：US13055891

申请日：2009-07-31

申请人： Itaru Yokoyama ,  Kouji Katsumoto ,  Yasuo Kawamura

发明人： Itaru Yokoyama ,  Kouji Katsumoto ,  Yasuo Kawamura

IPC分类号： C01F11/46

CPC分类号： C01F11/46 ,  C01F11/466 ,  C01P2004/03 ,  C01P2004/61 ,  C01P2006/11 ,  C04B11/007 ,  Y10T428/2982

摘要： Disclosed is a process for the continuous modification of dihydrate gypsum. The process includes a hemihydration step of calcining the dihydrate gypsum as a raw material into hemihydrate gypsum and a recrystallization step of hydrating and recrystallizing the hemihydrate gypsum in an aqueous slurry to convert the hemihydrate gypsum into modified dihydrate gypsum of a crystalline form different from the dihydrate gypsum as the raw material. In the recrystallization step, the aqueous slurry in a recrystallization reaction tank is maintained at a constant temperature under stirring such that the aqueous slurry becomes uniform, and a feed rate of the hemihydrate gypsum to the recrystallization reaction tank and a discharge rate of the recrystallized and modified dihydrate gypsum from the recrystallization reaction tank are controlled such that the feed rate and the discharge rate become substantially equal to each other, whereby the feeding of the hemihydrate gypsum and the discharging of the recrystallized and modified dihydrate gypsum are conducted continuously or intermittently. According to the process, dihydrate gypsum as a starting raw material can be converted into high-purity, modified dihydrate gypsum of large crystals by recrystallizing the starting dihydrate gypsum after it is once calcined into hemihydrate gypsum although such modified dihydrate gypsum is not available in general.

摘要翻译： 公开了连续改性二水石膏的方法。 该方法包括将二水石膏作为原料煅烧成半水石膏的半水合步骤和将水泥浆中的半水石膏水合和重结晶以将半水合石膏转化成不同于二水合物的结晶形式的改性二水石膏的重结晶步骤 石膏为原料。 在再结晶步骤中，将再结晶反应槽中的含水浆料在搅拌下保持在恒定温度，使得水性浆液变得均匀，并且半水石膏对再结晶反应槽的进料速率和再结晶和 控制来自再结晶反应槽的改性二水石膏使得进料速率和排出速率基本上彼此相等，从而连续地或间歇地进行半石膏的供给和再结晶和改性的二水合石膏的排出。 根据该方法，作为起始原料的二水石膏可以在一次煅烧成半水石膏之后，将起始二水石膏重结晶，可以转化为大晶体的高纯度，改性二水石膏，尽管这种改性二水石膏一般不可用 。

公开(公告)号：US20110135930A1

公开(公告)日：2011-06-09

申请号：US13055891

申请日：2009-07-31

申请人： Itaru Yokoyama ,  Kouji Katsumoto ,  Yasuo Kawamura

发明人： Itaru Yokoyama ,  Kouji Katsumoto ,  Yasuo Kawamura

IPC分类号： C01F11/46

CPC分类号： C01F11/46 ,  C01F11/466 ,  C01P2004/03 ,  C01P2004/61 ,  C01P2006/11 ,  C04B11/007 ,  Y10T428/2982

摘要： Disclosed is a process for the continuous modification of dihydrate gypsum. The process includes a hemihydration step of calcining the dihydrate gypsum as a raw material into hemihydrate gypsum and a recrystallization step of hydrating and recrystallizing the hemihydrate gypsum in an aqueous slurry to convert the hemihydrate gypsum into modified dihydrate gypsum of a crystalline form different from the dihydrate gypsum as the raw material. In the recrystallization step, the aqueous slurry in a recrystallization reaction tank is maintained at a constant temperature under stirring such that the aqueous slurry becomes uniform, and a feed rate of the hemihydrate gypsum to the recrystallization reaction tank and a discharge rate of the recrystallized and modified dihydrate gypsum from the recrystallization reaction tank are controlled such that the feed rate and the discharge rate become substantially equal to each other, whereby the feeding of the hemihydrate gypsum and the discharging of the recrystallized and modified dihydrate gypsum are conducted continuously or intermittently. According to the process, dihydrate gypsum as a starting raw material can be converted into high-purity, modified dihydrate gypsum of large crystals by recrystallizing the starting dihydrate gypsum after it is once calcined into hemihydrate gypsum although such modified dihydrate gypsum is not available in general.

摘要翻译： 公开了连续改性二水石膏的方法。 该方法包括将二水石膏作为原料煅烧成半水石膏的半水合步骤和将水泥浆中的半水石膏水合和重结晶以将半水合石膏转化成不同于二水合物的结晶形式的改性二水石膏的重结晶步骤 石膏为原料。 在再结晶步骤中，将再结晶反应槽中的含水浆料在搅拌下保持在恒定温度，使得水性浆液变得均匀，并且半水石膏对再结晶反应槽的进料速率和再结晶和 控制来自再结晶反应槽的改性二水石膏使得进料速率和排出速率基本上彼此相等，从而连续地或间歇地进行半石膏的供给和再结晶和改性的二水合石膏的排出。 根据该方法，作为起始原料的二水石膏可以在一次煅烧成半水石膏之后，将起始二水石膏重结晶，可以转化为大晶体的高纯度，改性二水石膏，尽管这种改性二水石膏一般不可用 。