Ozone modified lignin chelate fertilizer and preparation method thereof

The invention provides an ozone modified lignin chelate fertilizer and a preparation method thereof. According to the method, lignin is used as raw materials; the lignin is subjected to alkali regulation, ozone oxidation, alkali regulation, reaction with chloroacetic acid, acid regulation, chelation with medium trace elements and the like; the ozone modified lignin chelate fertilizer is prepared.The method is characterized in that firstly, ozone is used for oxidizing the lignin; the molecular weight of the lignin is reduced; the content of hydroxy and carboxyl in the lignin is improved; then,etherification is further performed; the content of carboxyl in the lignin is increased; the chelating capability of the carboxyl is improved; then, the synergistic effect of medium trace elements and modified lignin with high chelating capability is used; the chelate fertilizer is prepared. The prepared chelate fertilizer is favorable for the fertilizer compounding; the crop absorption capacitycan be obviously improved.