Purification Of Crude Anthracene

Crude anthracene, which is composed of 30%～40% anthracene,20%～30% phenanthrene and 15%～20% carbazole, is a semi-finished product in processing coal tar. It is widely used in chemical industry and is a main raw material for dyes, plastics, synthal, synthetic resin, synthetic fiber, synthetic drugs and pesticides. A major use of anthracene is to produce anthraquinone through oxidation. Anthraquinone is an essential intermediate of dye and can serve as cooking additive in papermaking and as raw material for ADA (a kind of desulfurizer).Fine carbazole is a basic material in producing permanent violet RL which is called the king of violet dye. Not only can people reduce environment pollution but also they can fully make use of resources by extracting anthracene and phenanthrene from crude anthracene. However, it is a waste of resources that most of the crude anthracene in China were sold as raw materials in a low price. During the process of the separation and extraction of anthracene, phenanthrene and carbazole from crude anthracene by solvent extraction crystallization method, the optimization of process conditions and the rational choice of solvents are closely related to the solubility of anthracene, phenanthrene and carbazole in solvents, And most of the Extracting agent were a play toxic benzene kind material.This paper studied the extraction conditions for anthracene, phenanthrene and carbazole from dimethylbenzene and 200# solvent naphtha respectively in the method of solvent extraction, examine the influence of dissolving temperature and volume-mass ratio on crude anthracene purification. In addition, qualitative and quantitative analyses were conducted on 200# solvent naphtha and crude anthracene before and after it was purified using gas chromatography-mass spectrometry, so that the best extraction condition for anthracene, phenanthrene and carbazole respectively was concluded. The dimethylbenzene has a medium toxicity and 200# solvent naphtha has a Lower toxicity, Therefore this experiment process improvements in later has certain directive significance.The crystallization of crude anthracene by dimethylbenzene is best when the solution temperature is 25℃, the solution time is 2.5h, and the mass-to-volume ratio is 2.8ml/g; The purification of crude anthracene by 200# solvent naphtha is best when the solution temperature is 30℃, the solution time is 2.5h, and the mass-to-volume ratio is 2ml/g.