Abstract:The distribution of lignin in forage was discussed in detail, the in vitro digestion of forage was analyzed, and the preparation methods of lignin was summarized. A new technical idea of enrichment of herbivorous animal excrement, purification of lignin and preparation of oxygen pressure leaching dispersant was put forward. By using herbivorous animals to digest, decompose and absorb nutrients such as protein, fat, starch and crude fiber in plants, lignin remains in the excrement and natural enrichment of lignin was realized. Lignosulfonate was prepared from herbivorous animal excrement, which increases the unit output of lignosulfonate and reduces the processing cost. This technology combines the characteristics of smelting enterprises and grassland ecology, makes full use of local grassland grass and herbivorous animal excrement to provide raw materials for preparing lignin for zinc oxygen pressure leaching, and forms a characteristic process combining plant-animal-zinc smelting in multiple fields