Preparation method of carbon excited slag brick

Abstract

The invention relates to a preparation method of a carbon excited slag brick. The preparation method includes: mixing slag micropowder within a certain grain size range and obtained after smashing andiron separation, slag fine particle, phosphogypsum and water to form a brick blank, and preserving the brick blank in high-partial-pressure CO2 environment to obtain a high-strength slag brick product. Coal ash, silica fume, sodium sulfate and sodium carbonate can be added into raw materials of the carbon excited slag brick. The problem that a lot of slag and phosphogypsum cause emission pollution and are low in utilization rate is solved, the objective of waste reutilization is achieved, and the preparation method has good social benefit, economic benefit and environment benefit.

Description

technical field [0001] The invention relates to the technical field of building materials and solid waste, in particular to a method for preparing carbon-activated steel slag bricks. Background technique [0002] my country's steel output ranks first in the world (accounting for about 50% of the world). In 2015, the production of steel slag was about 115 million tons (t), but the comprehensive utilization rate of steel slag is less than 15%. The utilization rate and the sustainable development of the steel industry are of great significance. The steel slag of most steel mills in my country will go through the crushing and iron selection process after being discharged, and the steel slag can be prepared into graded steel slag of different particle sizes, but because the steel slag contains a considerable amount of f-CaO, its stability is poor, and it is directly Cracks or flakes easily when used in aggregates. Steel slag also shows poor activity when used as cement admixture ...

AI Technical Summary

Problems solved by technology

[0002] my country's steel output ranks first in the world (accounting for about 50% of the world). In 2015, the production of steel slag was about 115 million tons (t), but the comprehensive utilization rate of steel slag is less than 15%. The utilization rate and the sustainable development of the steel industry are of great significance

[0005] At present, there are two bottlenecks (poor grindability and poor stability) and a short board (poor activity) in the application of steel slag to cement materials.

The first bottleneck is that the steel slag contains iron oxides, which leads to its poor grindability, and the second bottleneck is the hydration product Ca(OH) 2 , Mg(OH) 2 The large equal volume expansion rate leads to poor stability. The short board is that the crystallization of steel slag is relatively complete during the formation process, resulting in poor activity.

In the prior art, for example, in the Chinese patent CN104961495A, the grinding of steel slag may cause huge energy consumption, which is not worth the loss, and the direct use of industrial waste gas will inevitably have the problem of low utilization efficiency

In the Chinese patent CN101250050A, magnetic separation is used for screening is not strict enough, because the mineral composition of steel slag is directly related to the production process of each steelmaking plant, and the iron content in it is unstable

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