Process for producing moderate temperature modified bitumen by continuously pressurizing and hot-polymerizing at two stages connected in series

Abstract

The invention relates to a method for manufacturing high-quality intermediate temperature modified pitch through two-section serial continuous pressurizing hot polymerization. The method comprises the following steps that: mid-temperature pitch is made into modified pitch by a two-section serial reaction kettle through low-pressure heating polycondensation; heating precracking reaction is carried out during a first section, while heating polycondensation reaction is carried out quickly during a second section so as to increase the content of toluene insoluble and reduce the content of quinoline insoluble, thereby increasing a beta value; the reacted material is fed in a flash tower, and the softening point of the modified pitch is adjusted inside the flash tower; and the tail gas of a flash system is fed in a flue gas absorption system to be absorbed by circular wash oil, and then is discharged through a chimney. The method can manufacture intermediate temperature modified pitch which meets special requirements and has a lower softening point (80 to 90 DEG C), a controllable softening point amplitude of between 1 DEG C below zero and 1 DEG C and higher beta resin content (more than 18 percent), thereby providing a high-quality raw material for making an ultra-high power graphite electrode.

Description

technical field [0001] The invention relates to a method for preparing medium-temperature modified asphalt, in particular to a method for industrially producing high-quality modified medium-temperature asphalt by two-stage serial series continuous pressurized thermal polymerization. Background technique [0002] Modified asphalt is an important raw material for the production of graphite electrodes, anode paste, anode carbon blocks and other carbon products. It has excellent properties such as good bonding performance, excellent electrical conductivity, good electrode oxidation resistance and thermal stability. It is generally used as a binder for carbon products instead of medium temperature pitch. [0003] With the development of large-volume high-power DC electric arc furnaces and large-scale aluminum electric energy cells, higher requirements are put forward for large-scale ultra-high power (UHP) electrodes, high power (HP) electrodes and prebaked anode carbon blocks. T...

AI Technical Summary

Problems solved by technology

[0022] Although the quinoline insolubles of the treated modified pitch can meet the national standard, the softening point is too high to meet the needs of producing high-power graphite electrodes that meet the national standard.

[0023] Asphalt is very easy to form coke on the inner wall of the reactor, it is difficult to remove, and the valve is often unable to open;

[0024] Generally, the reaction pressure is low and the reaction time is long (about 8 hours), while the reaction time is short, the reaction pressure is high (1-1.2Mpa), the process is complicated, the equipment requirements are high, and the production volume is limited. The quality is not stable;

[0025] There is a single method to adjust the softening point of modified asphalt, and the fluctuation range of the softening point is large, which cannot meet the requirements of special asphalt customers such as the fluctuation range of the asphalt softening point within ±1°C

[0026] As far as we know, there is no process method for continuous low-pressure heat polymerization in series to produce medium-temperature modified asphalt.

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