Generally speaking, coal containing fulvic acid (peat, lignite, weathered coal) is used as raw material. The content of fulvic acid in some raw materials is not high, so it needs to be oxidized and degraded in advance. Total humic acid is extracted from raw materials with caustic soda solution, and then neutralized with acid to precipitate black humic acid and brown humic acid, leaving only fulvic acid (of course, there are a lot of inorganic salts in the solution). Crude fulvic acid can be directly used in agriculture. If you want to get refined fulvic acid, you must pass through macroporous adsorption resin and ion exchange resin, and then concentrate and dry to get pure fulvic acid. The main production equipment are: extractors, centrifuges, filters, resin columns, evaporators, dryers, etc.