Method for preparing lightweight aggregate from silicothermic magnesium smelting slag

Abstract

The invention discloses a method for preparing lightweight aggregate from silicothermic magnesium smelting slag. The method comprises the following steps of: 1, putting slowly cooled silicothermic magnesium smelting slag into a ball mill, and grinding and sieving to obtain magnesium slag powder; 2, putting the magnesium slag powder into a granulator, spraying water to the magnesium slag powder, and carrying out rotary granulation to obtain magnesium slag ceramsite; 3, pre-curing the magnesium slag ceramsite to obtain pre-cured magnesium slag ceramsite; and 4, carbonizing the pre-cured magnesium slag ceramsite in a closed container into which hot flue gas is introduced, and naturally cooling to obtain carbonized magnesium slag lightweight aggregate. According to the method, the magnesium slag ceramsite is prepared from the slowly-cooled silicothermic magnesium smelting slag as a raw material and is pre-cured and carbonized in sequence, so that a large number of small holes are formed in the magnesium slag ceramsite, the density of the carbonized magnesium slag lightweight aggregate is reduced, the diffusion efficiency of carbon dioxide gas is improved, the carbonization time is shortened, uniform carbonization is achieved, the carbonization degree is improved, the strength of the magnesium carbide slag lightweight aggregate is improved, and the high-strength and lightweight magnesium carbide slag lightweight aggregate is obtained.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a method for preparing light aggregate from magnesium smelting magnesium slag by silicon thermal method. Background technique [0002] With the expansion of my country's magnesium metal industry, on the one hand, the output of magnesium slag from silicithermal smelting has increased year by year, which has caused certain harm to the environment and human health, making the resource reuse of magnesium slag imminent; on the other hand, the magnesium industry Carbon dioxide emissions in carbon dioxide and other industrial waste gases have caused the greenhouse effect to become increasingly serious. The capture and utilization of carbon dioxide has also become a key focus of industry and scientific research around the world. The carbonization of magnesium slag cementitious materials came into being under this background. At the same time, with the deepening of m...

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Problems solved by technology

The ease of grinding and low price (only freight) of magnesium slag makes it one of the suitable substitute raw materials, but there is still a lack of related reports and inventions

[0003] In addition, the existing technology still has some non-negligible defects that limit the application of magnesium slag lightweight aggregates in actual production, such as: low efficiency caused by too long carbonization time, and the density of magnesium slag after carbonization exceeds the national standard for light aggregates. Requirements for aggregates, additional energy consumption brought about by steps such as air cooling of magnesium slag pretreatment, high energy consumption brought about by high temperature and high pressure environment of carbonization subsequent treatment, incomplete utilization of heat energy carried by flue gas during carbonization process, etc.

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