Process for continuously removing quinoline insolubles in coal tar pitch

Abstract

The invention provides a process for continuously removing quinoline insolubles from coaltar asphalt. In the process, after a working procedure of mixing materials and solvent, the mixture continuously enters to the lower part of a settling tank; a mixture separating working procedure is carried out in the settling tank; clear solution separated from the mixture is continuously discharged from the upper part of the settling tank, and sediments are sent out from the bottom of the settling tank; the solvent consists of aliphatic hydrocarbon and aromatic hydrocarbon according to the proportion of 1 to 0.5-1 to 1.5; and the flow ratio of pit asphalt and the solvent in the materials is 1 to 0.6-1 to 2.0. The OI content in the purified asphalt is low, and the clear solution loss of the supernatant clear solution is reduced due to the continuous operation, thus the purified asphalt product has high yield coefficient and the solvent also has higher recovery coefficient.

Description

technical field [0001] The invention relates to a pitch purification process, in particular to a new continuous process for removing quinoline insolubles (QI) from coal tar pitch. Background technique [0002] Pitch is a by-product in the process of coal tar processing. Because of its high yield, its processing technology and the added value of its products directly affect the economic benefits of coking enterprises. The production and preparation of coal-based needle coke, coal tar pitch-based carbon fiber, coal tar pitch impregnating agent and mesophase pitch all require purified coal pitch raw materials with low quinoline insoluble (QI) content, while coal tar contains raw QI The representative impurity can seriously hinder the preparation of above-mentioned high-quality high value-added coal tar pitch product. At the same time, the impurities contained in coal tar can easily cause blockage of coal tar deep processing equipment, thereby affecting the quality of coal tar ...

AI Technical Summary

Problems solved by technology

The disadvantages of the above method are: 1, the purification effect of the static sedimentation separation method is poor, and the QI content in the asphalt after purification is more than 1%; 2, the centrifugal separation method equipment operation cost is high, and the processing capacity is small; 3, hot-melt filtration 4. Intermittent solvent static sedimentation method has better purification effect, but the solvent consumption is large, the process energy consumption is also large, and the interface between the two phases of oil residue is unclear Causes high difficulty in industrialization

The yield of the purification product of solvent extraction and solvent flocculation method is low; 5, the recovery rate of solvent in solvent centrifugation method is low

[0005] Invention patent application 200510136738.1 discloses a production method for purifying asphalt. The method is an intermittent solvent settling method, which uses a stirred tank as a mixing and QI settling equipment for raw materials and solvents, which causes the following problems: oil residue two-phase The unclear interface makes the QI content in the purified bitumen still relatively high; to realize industrial continuous operation, multiple stirring tanks must be switched and used, so that the investment in equipment is large; Contamination of the supernatant, when the supernatant of the stirring tank is drawn out, it is impossible to completely pump it out, so that the loss of the supernatant will be caused, thereby reducing the yield of the product

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