关键词: 掺稀稠油, 长距离输送, 现场实验, 离心泵, 性能曲线

Abstract: This paper reviews the extraction methods of humic acid from lignite, the structure, chemical composition and characteristics of humic acid, and the production of humic acid fertilizer. Oxidative pretreatment of coal can increase the extractability of humic acid, but needs to improve its economic potential. The apparent molecular masses are determined by gel permeation chromatography and size exclusion chromatography. Mass spectrometry and flow field flow fractionation applied to molecular masses measurement has recently received great attention. Humic acid are supramolecular associations of diverse, relatively low molecular mass. Humic acid is mainly composed of aromatic acids and phenolic compound. Humic acid has been characterized by using tetramethyl-ammonium hydroxide pyrolysis-gas chromatography-mass spectrometry. Electrophoretic patters are often called fingerprints and can potentially be used for the classification. Phosphate-metal-humic (P-M-HA) complexes are the main component of humic acid fertilizer, and are able to decrease phosphate fixation in soils and increase phosphate uptake, which is a research hotspot in the area of humic acid.

Key words: diluted heavy crude, long-distance pipeline, field experiments, centrifugal pump, performance curve