Preparation method of steel slag aggregate

Abstract

The invention discloses a preparation method of a steel slag aggregate. The preparation method comprises the following steps: screening steel slag particles with sizes being 18-25mm, and drying the steel slag particles after washing; maintaining the dried particles in a carbonization reaction of which the pressure is 2-4MPa and the temperature is 35-55 DEG C for 3-5 hours to obtain carbonized steel slag particles; mixing 30-60% of papermaking sludge, 20-30% of lime and 10-40% of oil shale residues uniformly in percentage by weight, adding water according to a mass ratio of the mixture to water of 1:(0. 05-0.15), performing stirring for 10-60 seconds, then adding 10-25wt% of emulsified asphalt, and performing stirring for 10 to 60 seconds to obtain a uniformly mixed material; and preparing gravels into balls by taking carbide steel slag particles as cores, and the mixed material as a wrapping layer, and performing maintenance for 20-50 minutes under the conditions that the pressure is 4-6MPa, the temperature is 40-60 DEG C and the relative humidity is 60-95%, so as to obtain the steel slag aggregate. The obtained steel slag aggregate has a low water absorption rate, a low crushing index and a stable volume, and the preparation method is simple and low in cost.

Description

technical field [0001] The invention relates to a method for preparing steel slag aggregate, which belongs to the technical field of energy-saving building materials. Background technique [0002] Calculated according to the average level of the world's metallurgical industry, about 0.13 tons of steel slag is emitted for every ton of crude steel produced. The total amount of steel slag stockpiled in my country is 1 billion tons, which not only occupies a large amount of cultivated land, but also seriously pollutes the surrounding water and soil environment with harmful ions after exposure to the sun, rain and weathering, and even endangers human health. In order to adapt to the rapid development of the steel industry, in recent years, all steel-producing countries have put the issue of how to utilize steel slag on the important agenda, and have achieved some results. So far, the comprehensive utilization of steel slag mainly involves the following fields: return to metallur...

AI Technical Summary

Problems solved by technology

However, the comprehensive utilization rate of steel slag is less than 15% at present, and one of its uses is as concrete aggregate

However, when steel slag is used as concrete aggregate, there are serious problems: (1) the high content of free magnesium oxide can easily cause volume expansion; (2) due to the high temperature of 1650 ° C, the surface layer has a porous structure with high porosity and high water absorption. High crush index