Lime: for steelmaking, the particle size of the active lime requirement is to ensure that the requirements of steel-making process at the time of slagging speed and effectiveness. If lime limestone particle size is too large to sell ultra-fine powder, the reaction time will lead to lime particles and molten steel is lengthened, so slow down and affect slagging slagging effect. Conversely, if the particle size is too small lime, at the time of steelmaking dust particles or splashes easily cause deteriorated operating environment. Effect of limestone composition of wet flue gas desulfurization performance: sales of ultra-fine powder usually limestone, calcium carbonate in limestone weight percentage should be higher than 85%, due to impurities and to cause some problems when running content is too low ultra-fine powder of limestone, resulting in increased consumption and transportation costs absorbent, gypsum purity decreases. China is rich in limestone resources, CaCO3 content of the limestone FGD system uses most of the power plants of more than 90%.