US 12,338,180 B2
Process for producing microcrystalline alpha-alumina by microwave calcination
Zhiang Sun, Zhengzhou (CN); Feifei Liang, Zhengzhou (CN); Xiaohui Jiang, Zhengzhou (CN); Bo Dong, Zhengzhou (CN); Qian Wang, Zhengzhou (CN); Dongmei Zhang, Zhengzhou (CN); Junjian Wang, Zhengzhou (CN); Yanan Xue, Zhengzhou (CN); Zhikai Xu, Zhengzhou (CN); Fang Wang, Zhengzhou (CN); Yanjun Yang, Zhengzhou (CN); Mingjing Li, Zhengzhou (CN); and Meishan Shao, Zhengzhou (CN)
Assigned to HENAN CHANGXING INDUSTRY CO, LTD., Zhengzhou (CN)
Filed by HENAN CHANGXING INDUSTRY CO, LTD., Zhengzhou (CN)
Filed on Apr. 28, 2022, as Appl. No. 17/731,274.
Claims priority of application No. 202110474923.0 (CN), filed on Apr. 29, 2021.
Prior Publication US 2022/0250987 A1, Aug. 11, 2022
Int. Cl. C04B 35/10 (2006.01); C04B 35/626 (2006.01)
CPC C04B 35/10 (2013.01) [C04B 35/6261 (2013.01); C04B 2235/3217 (2013.01); C04B 2235/606 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A process for producing microcrystalline alpha-alumina by microwave calcination, wherein, comprising the following steps:
S1. adding a composite mineralizer to an alumina rave material and nixing uniformly, to obtain a mixture;
S2. putting the mixture obtained in the step S1 into a ball mill for ball milling, to obtain a milled alumina powder;
S3. adding a certain proportion of a microwave absorbent into the milled alumina powder obtained in the step S2 and stirring evenly, and then extruding by a press, to obtain an alumina green body;
S4. drying the alumina green body obtained in the step S3, to adjust a moisture content of the alumina green body;
S5. feeding the alumina green body dried in the step S4 into a microwave kiln, then heating the microwave kiln to a set temperature, and calcining for a certain period of time, to obtain an alpha-alumina clinker; and
S6. pulverizing the alpha-alumina clinker obtained in the step S5, to obtain the microcrystalline alpha-alumina.