TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The inorganic salt is chosen from sodium salt and ammonium salt of hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The calcium hydroxide solution is dripped in obtained mixture (b) to precipitate sulfate radical, carbonate radical, phosphate radical or silicic acid radical ion, or to remove sulfate, nitrate, carbonate, hydrochloride, phosphate or silicate by ion-exchange membrane method or electrodialysis to obtain mixture (j). The carbon dioxide gas or carbonic acid solution is injected to obtained mixture (j) to precipitate redundant calcium ion and precipitant is removed to obtain mixture (k). The nitric acid solution is dripped in obtained mixture (k) to recovery mixture (b) in acid state, preferably the pH of mixture is 4 less than. Manufacture of mixed fuel containing lignin particles further involves dissolving pulp waste liquor in solvent, dewatered lignin in organic solvent, biomass raw material containing lignin in organic solvent, acid lignin in organic solvent, mixing acid lignin with fuel oil, surfactant and organic solvent, emulsifying mixture, obtaining organic solvent or colloid-shape mixed fuel containing acid lignin, spraying organic solvent or mixture containing acid lignin in fuel oil, diluting or evaporating organic solvent, obtaining fine lignin particles dispersed in fuel oil, filtering, and obtaining fine lignin particles. The metal-ion chelating agent is further added to the mixture in manufacture of mixed fuel. The mixed fuel is added with acid and/or salt, and surfactant and/or antioxidant. Preferred Composition: The organic solvent contains water. The second fuel contains compound chosen from glycerin, ethanol, methanol, and alkaline amine compounds e.g. monoethanolamine, diethanolamine, triethanolamine and ammonia. The acid is nitric acid and salt is sodium nitrate. The content of fuel oil in mixed oil is 0-99%. The fuel oil is ethanol, gasoline, diesel oil, kerosene, heavy oil, lubricating oil or lubricant. The content of water in acidic lignin colloid or particles is 50-90% or 1-15%. The pH of water in acidic lignin colloid or particle is acidity.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The inner wall of container for heating and dewatering treatment is coated using polytetrafluoroethylene.