GRADING EXTRACTION METHOD OF HUMIC ACID IN SOIL

摘要

The invention discloses a method for graded extraction of humic acid in soil. The method for graded extraction comprises the following steps: a step a of soil pretreatment; a step b of soil pickling; a step c of soil humic acid extraction; a step d of silica removal out of humic acid; a step e of heteroacid removal out of the soil humic acid; a step f of subfraction grading of the soil humic acid; a step g of soil humic acid desalting and curing. According to the method, humic acid solution can be extracted out of soil, a resin separation technology is utilized to grade the humic acid, and after purification, graded humic acid subfractions are obtained finally.