The invention provides a preparation method of medical
fulvic acid. The preparation method comprises the following steps: with high-quality
brown coal as a
raw material, adding the
raw material into pure water in a proportion of 1 to 1.5, and removing heavy
metal ions and other micromolecule impurities in the
brown coal by virtue of an emulsifying
machine; introducing the
brown coal into a
cavitation ionic tube, carrying out molecular
chain scission by virtue of
field energy, and standing for
settling for 5 hours; extracting supernate, adding 12% of
calcium bicarbonate into a reaction kettle,heating to 85 DEG C, and continuously reacting for 60-120 minutes, so as to obtain a
calcium fulvate solution; discharging the supernate, adding 8% of 98%
carbonic acid, continuing to react for 150 minutes, introducing the mixture into a centrifugal
machine, carrying out high-speed separation so as to obtain effective component liquid of
sodium humate; separating pure
fulvic acid by virtue of an electric film, introducing
fulvic acid into a drier, and
drying, so as to obtain a medical fulvic acid finished product. The fulvic
acid content of the medical fulvic acid finished product is 99.9%, and the water
solubility of the medical fulvic acid finished product is 99.9999%. The preparation method has the advantages that fulvic acid is high in purity, water
solubility and medical value.