The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 2024
Filed:
Feb. 03, 2024
North University of China, Taiyuan, CN;
Shanxi Zhongbei New Material Technology Co., Ltd., Taiyuan, CN;
Yaqing Liu, Taiyuan, CN;
Yingfang Tong, Taiyuan, CN;
Peng Gao, Taiyuan, CN;
Guizhe Zhao, Taiyuan, CN;
NORTH UNIVERSITY OF CHINA, Taiyuan, CN;
SHANXI ZHONGBEI NEW MATERIAL TECHNOLOGY CO., LTD., Taiyuan, CN;
Abstract
A method for preparing a weathered coal-derived humic acid/urea-formaldehyde slow-release fertilizer granule by reactive extrusion process with depolymerization-activation-polycondensation trinity is provided. In an alkaline environment, paraformaldehyde is depolymerized into formaldehyde small molecules, which react with urea to form monohydroxymethylurea and dihydroxymethylurea. Under the strong shearing action of screws of the twin-screw reactive extruder, the macromolecular weathered coal-derived humic acid is depolymerized into relatively small molecule weathered coal-derived humic acid, and abundant active carboxyl groups are exposed, some of which immediately undergo dehydration condensation with —NHon the urea-formaldehyde molecule produced by the polycondensation of hydroxymethylurea during the reactive extrusion process to generate weathered coal-derived humic acid/urea-formaldehyde and its granules.