Yingkou Leixuan Refractory Co., Ltd. recently carried out a discussion on the treatment of magnesium oxide wet flue gas desulfurization wastewater treatment technology. Magnesium oxide method is another main desulfurization technology second only to calcium method in wet flue gas desulfurization technology. According to reports, the desulfurization process of magnesium oxide regeneration method was first successfully developed by Chemico-Basic of the United States in the 1960s. After the 1970s, Philadelphia Electric Power Company (PECO) cooperated with United & Constructor to study the desulfurization process of magnesium oxide regeneration method. After several thousand hours of trial operation, a full-scale FGD system and two magnesia regeneration systems were constructed in three units (two of which were 150MW and 320MW respectively), which were built and put into operation in 1982, and were put into operation in 1992. After 2000, the sulfuric acid manufacturing plant will be shut down, and the reaction product magnesium sulfate will be sold directly. In 1980, DUCON Company of the United States successfully built and implemented a magnesium oxide wet desulfurization system in PHILADELPHA ELECTRIC EDDYSTONE STATION, which has been in operation so far with good results. Subsequently, South Korea and Taiwan also developed their own wet magnesium desulfurization technology. Currently, 95% of power stations in Taiwan use magnesium oxide desulfurization.

In recent years, domestic magnesium oxide wet desulfurization has developed rapidly. In 2001, the Department of Environment of Tsinghua University undertook the subject of "Industrialization of Magnesium Desulfurization Process for Large and Medium-sized Boilers" in the "863" plan. In-depth research has been carried out on the optimal design of the tower and the recycling and utilization of by-products, and the pilot test has been carried out on the 4t/h and 12t/h boilers, and the engineering application has been carried out on the 35t/h boiler. At present, large-scale magnesium-based flue gas desulfurization has been carried out in Binzhou Chemical Group Power Plant, Taigang Power Plant, Huaneng Xindian Power Plant, Sinopec Yizheng Chemical Fiber Thermal Power Plant, Weiqiao Aluminum Electric Power Plant, Anshan North America Thermal Power Plant, Lubei Chemical Power Plant, Taiwan Power plants and sintering machine plants of plastic-related enterprises (Ningbo, Kunshan, Nantong) thermal power plant, Minmetals Yingkou Medium Plate Sintering Machine Plant are under construction or put into operation.

Wet magnesium desulfurization process can be divided into magnesium oxide/magnesium sulfite method, magnesium oxide/magnesium sulfate disposal method, magnesium oxide/magnesium sulfate recovery method, etc. This paper mainly introduces the wastewater treatment process in the magnesia/magnesium sulfite process with a large scale and broad prospects.