With sulfuric acid (60 %), and nitric acid under catalyzing, cassava residue could be prepared into oxalic acid through hydrolyzation-oxidization-hydrolyzation.

• 经实验证明，在浓硫酸(60 %25)、浓硝酸和催化剂共同作用下，经水解-氧化-水解可成功地将木薯渣制备成草酸。