▎ 摘　　要

NOVELTY - Preparing potassium, manganese mixed fertilizers based on production of waste acid from graphene oxide comprises (i) generating waste acid during preparation of graphene oxide and removing solid; (ii) adding neutralizer with stirring and neutralizing; (iii) adding neutralizing agent and transferring the filtrate; (iv) concentrating filtrate, evaporating, cooling and filtering slurry after cooling; (v) transferring filtrate into denitration reactor and carrying out denitration reaction; and (vi) drying filter cake form step (iii) and (iv). USE - The method is useful for preparing potassium, manganese mixed fertilizers based on production of waste acid from graphene oxide (claimed). ADVANTAGE - The method is simple and economical. DETAILED DESCRIPTION - Preparing potassium, manganese mixed fertilizers based on production of waste acid from graphene oxide comprises (i) generating waste acid during the preparation of graphene oxide and removing solid matter in waste liquid; (ii) adding neutralizer with stirring to reduce acidity to neutral and neutralizing neutralizer when pH is neutral; (iii) adding neutralizing agent by membrane filter press material generated after carrying out solid-liquid separation and transferring the filtrate; (iv) concentrating filtrate in concentrated tank, evaporating to a crystal after the formation, transferring into cooling tank, cooling and filtering slurry after cooling; (v) transferring filtrate into denitration reactor and carrying out denitration reaction; and (vi) drying filter cake form step (iii) and (iv). An INDEPENDENT CLAIM is also included for system for preparing potassium, manganese mixed fertilizers, comprising clarification cell with glass gauze, a neutralization cell, a first solid-liquid separation cell, a concentration cell with a cooling tank, second solid-liquid separation tank and denitration reaction tank, drying box and a packaging line respectively is connected with the solid output ends of the first solid-liquid separation tank and the second solid-liquid separation tank.