North University of China

Shanxi Zhongbei New Material Technology Co., Ltd.

Peng Gao

Guizhe Zhao

Yaqing Liu

Yingfang Tong

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.

Method for preparing weathered coal-derived humic acid/urea-formaldehyde slow-release fertilizer granules by reactive extrusion process with depolymerization-activation-polycondensation trinity and fertilization method

Growing community of inventors

Taiyuan, China

Peng Gao