Preparation technology of modified asphalt by adding stabilizer at later stage

Abstract

The invention discloses a preparation technology of a modified asphalt by adding a stabilizer at later stage, characterized by dividing heated molten matrix asphalt into two parts, wherein most matrix asphalt is used as the matrix asphalt added at earlier stage, and a small part of the matrix asphalt is used as the matrix asphalt added at later stage; then adding a modifier, a compatilizer and the matrix asphalt added at earlier stage in a mixing tank to uniformly mix to obtain a swelling system, processing the swelling system by using a colloid mill, then sending the processed swelling system into the tank to stir for developing; after the swelling reaction of the matrix asphalt added at earlier stage and the modifier is stable, adding the matrix asphalt added at later stage and the stabilizer, continuing to stir to develop to obtain the modified asphalt. According to the invention, there is no false liquid level occurred in the mixing tank during the production process, there is no local sharp reaction occurred, there is no block that is difficult to be molten, thus the production efficiency is better than existing technology of synchronous adding agents, and the quality of the modified asphalt is good.

Description

technical field [0001] The invention relates to a process for preparing modified asphalt after adding a stabilizer. Background technique [0002] Modified asphalt is prepared by mixing components including base asphalt, modifiers, compatibilizers and stabilizers. The current production of modified asphalt adopts a synchronous dosing process. The production process of this process is: the temperature of the oil at the outlet of the heat conduction oil furnace is raised to 220°C, and the base asphalt is heated to 200±5°C, and the modifier, Dosing frequency of compatibilizer and stabilizer, as well as base bitumen feeding frequency and mixing tank level. Then, modify the flow of base asphalt into the product tank, add base asphalt, modifier, compatibilizer and stabilizer into the mixing tank at the same time according to the formula, stir and mix, and then put it into the finished product tank through the colloid mill for asphalt development. After the feeding is completed ac...

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Problems solved by technology

[0003] However, in actual production, there are many problems in the synchronous dosing process, mainly as follows: (1) Unstable control of the boundary level of the mixing tank: since the liquid level of the mixing tank is automatically controlled, the modifier and the stabilizer are stable during simultaneous dosing. The agent reacts violently with the base asphalt to form small clumps. Under the action of the mixer, these small clumps will stick to the liquid level gauge, resulting in false liquid level.

Base asphalt is fed according to the liquid level. Once a false liquid level occurs, the addition of base asphalt will be interrupted, while the modifier and stabilizer will continue to be added, which will cause the material to stick and lead to discontinuous production. There is a risk of grinding blockage at any time; (2) The temperature of the production is too low, the viscosity of the asphalt is high, and the dosing speed is too fast, when the stirring and pump circulation are not turned on or the stirring is poor, the modified asphalt will partially react and form a hard-to-melt agglomerates directly affect the quality of modified asphalt

As a result, the quality of modified asphalt products is poor, mainly as follows: low softening point, low ductility, high viscosity

(3) After the modified asphalt enters the product tank, at least two sets of mixers need to be started for mixing, which consumes a lot of energy

(4) Due to the simultaneous addition of additives, modifiers, stabilizers and compatibilizers are mixed with asphalt to increase the viscosity of the mixture. These mixtures will remain on the liquid level gauge as the production process progresses, and cannot be The asphalt is taken away, which will cause the liquid level gauge to show a false liquid level

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