| Abstract:A process using phosphoric acid to precipitate lignin from straw pulping black liquor was investigated, the conditions were optimized, as pH=3, T=60℃, the yield of the precipitated lignin was 87%. The precipitated lignins at different pH were analyzed by infrared spectrum and ultraviolet spectral. The components of acid-precipitated lignin at pH=3 was analyzed, the result indicated that the precipitated lignin has the characteristic of fertilizer. |
