泥煤(泥炭、草炭),褐煤,风化煤中的腐植酸及其碱金属的盐类称游离腐植酸,而与铁铝钙镁所形成的难溶性腐植酸称结合腐植酸,两者之合称总腐植酸,其传统的组分分级通常是以碱直接抽出的部分称为腐植酸,其中可溶于丙酮、乙醇等溶剂的部分称棕腐酸,可溶于水及用稀酸从泥煤中洗下的部分称黄腐酸(或称富里酸),三者之和称总腐植酸,三种不同的组分在天然或人为条 Peat (peat, peat), lignite, weathering coal humic acid and alkali salts called free humic acid, and iron and calcium and magnesium formed by the insoluble humic acid, said the combination of humic acid, the combination of the two The total humic acid, said its traditional classification of components is usually directly extracted by alkali called humic acid, which is soluble in acetone, ethanol and other solvents, said parts of fulvic acid, soluble in water and with dilute acid from the mud Part of the washing of coal called fulvic acid (or fulvic acid), the sum of the three total humic acid, three different components in natural or artificial