Wet magnesia-magnesium sulfite calcination and reuse by-product sulfuric acid desulfurization technology
Magnesium sulfite is an industrial solid waste produced by the magnesium-based desulfurization process. There is currently no good treatment method, which has become a heavy environmental burden for power generation enterprises that use magnesium as a desulfurizer.
1. Technical principle

The process includes magnesium oxide slurry preparation system, flue gas system, sulfur dioxide absorption system, desulfurization slurry dehydration system, magnesium sulfite calcination and reuse system (containing sulfuric acid preparation subsystem), electrical system, thermal system and process water system. Magnesium oxide powder is used as a desulfurization absorbent, and water is added to prepare magnesium hydroxide slurry. The flue gas enters the absorption tower through the booster fan. In the absorption tower, the flue gas is mixed with the magnesium hydroxide slurry in reverse contact. The magnesium hydroxide is removed by a series of chemical reactions. After the slurry of the absorption tower is dehydrated by the vacuum belt dehydration system, a by-product magnesium sulfite solid is formed. The magnesium sulfite solid is dried to remove free water and crystal water, and then undergoes rotary calcination. The furnace is decomposed into magnesium oxide and sulfur dioxide at high temperature, and the generated magnesium oxide can be reused as a desulfurizing agent.
Technical Features

Technology is mature.

MgSO3 in the salt composition generated by reacting with SO2 is not easy to adhere to the wall due to its own characteristics, so the phenomenon of solid accumulation does not occur in the desulfurization equipment;

The desulfurization efficiency is over 95%, the absorption tower PH is 6.5-7, and the magnesium oxide recovery rate after calcination is 60%;

The desulfurization system is small in scale and occupies a small area;

The consumption of desulfurizer is greatly reduced, and the by-product chemical product sulfuric acid, so the operating cost is low.

4. Scope of application

Desulfurization of power plants and industrial furnaces, this process is suitable for flue gas desulfurization of any type of coal with sulfur content, and the desulfurization efficiency can reach more than 95%.