In China's O2 emissions, thermal power plants and coal-fired boilers are the main emission industries. Limestone desulfurization process is the most mature technology to control O2 emission in the world at present. The most common application is the limestone ultrafine vertical mill plug flow pulverizing process launched by Shanghai SBM, with desulfurization rate of 95%.

At present, most of the domestic power plants adopt wet FGD, limestone gypsum. It can be said that the fineness, quality, particle distribution and reactivity of limestone ultrafine powder are the key factors affecting the desulfurization effect.

The specific desulfurization process of ultra-fine limestone powder is as follows: firstly, the ultra-fine limestone powder with calcium content of more than 50% and fineness of more than 325 mesh is made into slurry to filter out O2 in coal-fired flue gas, so as to achieve the purpose of desulfurization in coal-fired power plant. In this process, the quality of limestone superfine powder is the key factor of desulfurization efficiency and environmental protection.