Method for combined production of lightweight magnesium carbonate and ammonium chloride based on carbon dioxide sequestration

Abstract

The invention relates to a method for the combined production of lightweight magnesium carbonate and ammonium chloride based on carbon dioxide sequestration. According to the technical scheme of the invention, the wastes of potassium salts dried in a salt lake are adopted as raw materials, and the pH value of a solution is adjusted by the liquid ammonia for the absorption of carbon dioxide in the industrial flue gas. An ammonium magnesium carbonate hydrate crystal generated during the above reaction is adopted as an intermediate product and the ammonium magnesium carbonate hydrate is refined to prepare the lightweight magnesium carbonate. In addition, the magnesium chloride raw material is added into an ammonium-rich solution after the reaction, and then the combined production of an ammonium chloride fertilizer is obtained after the solid-liquid separation process and the drying process. During the refining process of the ammonium magnesium carbonate hydrate, the generated carbon dioxide and the generated ammonia gas are fed back to the reaction solution to be re-absorbed, so that the utilization rate of raw materials is improved. The emission of the tail gas is reduced. During the salting-out process, a generated bittern concentrated liquid is fed back to a crystallization reactor to be used as raw materials for the absorption of carbon dioxide. The above method is energy-saving, environment-friendly, high in operability and easy to industrialize.

Description

technical field [0001] The invention relates to a process for sequestering carbon dioxide with minerals and using it to produce light magnesium carbonate, which belongs to the field of inorganic salt chemical industry and fertilizer production. Background technique [0002] According to the report of the Intergovernmental Panel on Climate Change (IPCC), since the middle of the 20th century, the extensive use of fossil fuels has led to a continuous increase in the content of atmospheric greenhouse gases, mainly carbon dioxide. This phenomenon is closely related to global climate change. In order to prevent further deterioration of the environment caused by global climate change, it is necessary to stabilize the carbon dioxide content in the atmosphere from both "source" and "sink". [0003] Since fossil fuels are in a dominant position now and even for a long time in the future, coal, oil, and gas are the main energy sources. In addition, the price of renewable energy will st...

AI Technical Summary

Problems solved by technology

At present, the production of magnesium carbonate hydrate and magnesium oxide in my country mainly relies on calcination of magnesite. This method consumes a lot of energy and most of the products are low-grade products.

Developed countries such as the United States, Japan, and the Netherlands often use sea brine to prepare magnesium carbonate hydrate, but because the process directly decomposes MgCl 2 ·6H 2 O produces HCl, causing serious equipment corrosion

In addition, my country currently has research on the preparation of magnesium oxide using magnesium carbonate trihydrate as an intermediate, which requires high preparation temperature and high energy consumption.

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