Experimental Study On Extracting Humic Acid From Huolinhe Lignite

The reserves of humic acid is huge and the distribution is wide, it has been extensively used in the fields like industry, agriculture, medicine, environment protection, etc. The lignite of China is the main source of the natural humic acid becauuse of it contains a lot of humic acid. This paper adopts the method of the raw coal preoxidation by nitric acid, uses sodium pyrophosphate and sodium hydroxide solution as the extraction agents, extracting humic acid from the lignite. The results indicate that the optimal processing condition can be achieved when nitrate concentrations is 12%, acid-coal proportion is 1:4, oxidized temperature is 90℃, oxidation time is 40 min, extraction liquid concentration is 12%, liquid-solid ratio concentration 200ml/g, extraction temperature is 100℃and extraction time is 140 min, the rate of humic acid production can reach to 41.18%. The infrared spectrum analysis of the standard humic acid and the products of the test show that the products in the experiment are indeed humic acid. Preliminary discussing the mechanism of the lignite preoxidation by nitric acid and the mechanism of adopting sodium pyrophosphate and sodium hydroxide solution as the extraction agents, adopt focal sodium and naohlye as an experiment extraction agent mechanism. The route of extracting humic acid from Huolinhe lignite not only can improve the lignite comprehensive utilization value but also can increase the economic efficiency of the enterprises, it has broadly development prospect.Through comparing the infra-redspectrum of the standard humic substances and the products, the results showed the test products are indeed humic acid. Preliminary discusse the mechanism of oxidation process and extraction. Experimental study and theoretical analysis shows that the route of the test is feasible, which can be got higher rate of humic acid, and realized the comprehensive utilization and efficient utilization of the lignite, established the research foundation of the followed pilot and industrialized mass production.