Key Technology Of Extract Fulvic Acid From Weathered Coal

Weathered coal refers to exposure to the ground and locates in the shallow ground, loses function as fuel and coking coal after weathering oxidation. Due to the low heat value, weathered coal had been abandoned and not managed, taken up much of the land and caused a series of environmental problems. Weathered coal’s reserve has no systematic statistics, but preliminary shows that weathered coal’s reserve of our country is rich, especially Shanxi, Xinjiang, Inner Mongolia, Heilongjiang, Jiangxi, Yunnan, Sichuan, Henan and other provinces. Weathered coal’s reserve of Shanxi reaches8billion tons, Inner Mongolia reaches5billion tons. There are more investigations show that Shanxi and Inner Mongolia’s weathered coal contain a large number of humic acid, and a number of fulvic acid.Fulvic acid is a kind of humic acid of soluble in water. Fulvic acid, small molecular weight, can dissolve in water, acid, alkali solution and also acetone and ethanol. It have been widely used in industry, agriculture, medicine, animal husbandry etc. Extract fulvic acid from weathered coal, with economy and environment double benefit, worthes researching.Literatures show that domestic scholars have a lot of researches about fulvic acid preparation methods. Include three categories:extraction, fermentation and Electrodialysis method. Extraction includes four kinds: base-dissolving acidification method, acidification method, ion exchange resin method and sulfuric acid acetone method. Product’s purity extracted by base-dissolving acidification method is low; acidification method has low yield; ion exchange resin method needs large energy consumption; sulfuric acid acetone method has a wider applicable scope but high production costs, and bigger toxicity. This project aims to provide a new method-sulfuric acid ethanol method, extracts fulvic acid from Shanxi, Inner Mongolia weathered coal. The results are summarized as follows:1、Four factors, solvent-to-solid radio, the water content in extracted solution, reaction time and acid-to-coal radio, were studied by designing orthogonal experiment. Experiment was analyzed with two kinds of methods, poor analysis and analysis of variance. Conclusion:best experimental conditions of Shanxi weathered coal is liquid-solid ratio6, the water content in extracted solution15%, reaction time1h, acid-to-coal radio0.100, in this condition, extraction yield is1.22%; Inner Mongolia weathered coal: liquid-solid ratio4, the water content in extracted solution15%, reaction time1h, acid-to-coal radio0.100, extraction yield is32.28%.2、Inner Mongolia weathered coal as raw material, according to significantly impact factor acid-to-coal radio, verifying test was designed to determine the best value. The result proves that0.100is credible.3、 Inner Mongolia weathered coal as raw material, in the best condition, compare extraction yield between Sulfuric acid ethanol method and Sulfuric acid acetone method. The result indicates:sulfuric acid acetone method is17.04%; sulfuric acid ethanol method attains32.28%.4、Analyze the quality of product. Include infrared mapping detection, fulvic acid, moisture, ash content determination. The results are as follows: the structure of product was studied by IR and the result is in accord with standard, fulvic acid content is47.63%, water content is28.39%, ash content is6.20%.