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Humic Acid Classification And Extraction
Sep 13, 2017


Classification of humic acid:

Classify by source: humic acid can be divided to two categories: natural humic acid and man-made humic acid. While natural humic acid can be divided into soil humic acid, coal coal humic acid, water humic acid and mould humic acid according to the existing field.

Classify by mode of generation: humic acid can be divided into primary humic acid and regenerated humic acid (including humic acid from natural weathered coal and artificial oxidized coal). 

Classify by solubility and color in solvent: humic acid can be divided into fulvic acid, almic acid and humus acid.

Classify by natural binding state: it can be divided to free humic acid and (Ca and Mg) combined humic acid. 

Classify by degree of humic acid decay(extinction coefficient): it can be divided to A type, B type(real humic acid) and RP type and P type(not matural humic acid) and so on.

Humic acid extraction:

For the same raw materialand same extraction conditions, different extraction agents and extraction process will have a greater impact on the extraction capacity of humic acid. Therefore, there are many problems in the extraction technology of humic acid. Normally, there are several extraction technologies:

1. Alkaline extraction

Normally, sodium hydroxide, potassium hydroxide, ammonia water will be used to extract.

2. Acid extraction

The main solvents include various organic and inorganic acids, such as nitric acid, oxalic acid, etc.

3. Neutral salt extraction

Neutral salt can be sodium fluoride, sodium oxalate, sodium pyrophosphate and so on.

4. Organic solvent extraction

Normally, organic solvents are two methylene sulfoxide, ethanol, acetone and so on.