US 12,083,491 B2
Ferrous sulfide-containing passivator for removing heavy metal from soil and preparation method and use thereof
Chunpeng Song, Kaifeng (CN); Chaoran Li, Kaifeng (CN); Mingming Lian, Kaifeng (CN); Xiaohong Li, Kaifeng (CN); and Zhijun Zhang, Kaifeng (CN)
Assigned to HENAN UNIVERSITY, Kaifeng (CN); and ENGINEERING RESEARCH CENTER FOR NANOMATERIALS CO., LTD., Jiyuan (CN)
Filed by Henan University, Kaifeng (CN); and Engineering Research Center for Nanomaterials Co., Ltd., Jiyuan (CN)
Filed on Aug. 19, 2022, as Appl. No. 17/891,170.
Claims priority of application No. 202110953814.7 (CN), filed on Aug. 19, 2021.
Prior Publication US 2023/0068171 A1, Mar. 2, 2023
Int. Cl. B01J 20/02 (2006.01); B01J 20/10 (2006.01); B01J 20/22 (2006.01); B01J 20/28 (2006.01); B01J 20/30 (2006.01); B09C 1/08 (2006.01); C09K 17/02 (2006.01)
CPC B01J 20/0229 (2013.01) [B01J 20/0266 (2013.01); B01J 20/103 (2013.01); B01J 20/22 (2013.01); B01J 20/28007 (2013.01); B01J 20/3085 (2013.01); B09C 1/08 (2013.01); C09K 17/02 (2013.01); B09C 2101/00 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method, comprising:
1) dissolving a sulfide in an alkaline solution to form a mixed solution with a pH of 12-13;
2) adding sodium silicate to the mixed solution and stirring for 0.5-1 hour at 20-40° C.;
3) adding an aqueous solution of a ferrous salt to the mixed solution containing sodium silicate, and allowing to react at 40-60° C. for 2-3 hours; where, with decrease of the pH of the mixed solution, sodium silicate is converted into silica nanoparticles, and the ferrous salt reacts with the sulfide to form ferrous sulfide; and
4) further adding an aqueous solution of an organic modifier to the mixed solution, and allowing to react at 40-60° C. for 1-2 hours to form a passivator slurry comprising surface-modified ferrous sulfide doped with silicon dioxide; filtering the passivator slurry through suction filtration to form a filter cake passivator or spray drying the passivator slurry to form a dry powdery passivator.