US 12,065,378 B2
Method for preparing low-background cement
Wen Huang, Beijing (CN); Yang Yu, Beijing (CN); Min Wang, Beijing (CN); Zhaijun Wen, Beijing (CN); Tingting Bao, Beijing (CN); Guang Yao, Beijing (CN); Xin Shen, Beijing (CN); Yun Liu, Beijing (CN); Jing Wang, Beijing (CN); Xianbin Wang, Beijing (CN); Zhongcheng Ma, Beijing (CN); Xianshu Gao, Beijing (CN); Kunyue Zhang, Beijing (CN); Guanbao Tang, Beijing (CN); Suihua Guo, Beijing (CN); Mingming Sun, Beijing (CN); and Ao Liu, Beijing (CN)
Assigned to CHINA BUILDING MATERIALS ACADEMY CO., LTD., Beijing (CN)
Filed by China Building Materials Academy Co., Ltd., Beijing (CN)
Filed on May 12, 2023, as Appl. No. 18/197,028.
Claims priority of application No. 202210830777.5 (CN), filed on Jul. 15, 2022.
Prior Publication US 2024/0018048 A1, Jan. 18, 2024
Int. Cl. C04B 28/14 (2006.01); C04B 7/42 (2006.01); C04B 7/44 (2006.01); C04B 14/46 (2006.01); C04B 22/06 (2006.01); C04B 40/00 (2006.01); G21F 1/04 (2006.01); C04B 111/00 (2006.01)
CPC C04B 28/14 (2013.01) [C04B 7/424 (2013.01); C04B 7/44 (2013.01); C04B 14/4618 (2013.01); C04B 22/066 (2013.01); C04B 40/0042 (2013.01); G21F 1/042 (2013.01); C04B 2111/00862 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method for preparing cement, the method comprising:
1) uniformly mixing a seed crystal of cement, C4AF whiskers, and high-magnesium raw material to yield a first mixture and calcining the first mixture at 1400-1500° C. to yield a first clinker, wherein the first mixture comprises 1.0-5.0 wt. % of the seed crystal of cement, 1.0-5.0 wt. % of the C4AF whiskers; and
2) grinding a second mixture of the first clinker and gypsum to a specific surface area of 320-360 m2/kg to yield a cement;
wherein:
the seed crystal of cement is a second clinker and has a specific activity of Ra-226 radioactive nuclides within 50 Bq/kg, and a MgO content of the second clinker is between 4.0 wt. % and 5.0 wt. %, with 50 wt. %≤C3S≤55.0 wt. %; and
the high-magnesium raw material has a MgO content between 2.5 wt. % and 3.0 wt. % and a specific activity of Ra-226 radioactive nuclides is within 40 Bq/kg.