School of Architecture and Civil Engineering, Anhui University of Technology, Maanshan, China.
Environ Technol. 2012 Apr-May;33(7-9):837-44. doi: 10.1080/09593330.2011.599428.
The characteristics of fly ash from the flue gas desulfurization (FGD) system are important for its reuse and are mainly depend on the desulfurization process. The physical and chemical properties of DSF ash, which refers to fly ash from the dry FGD system for the iron ore sintering process, were investigated. Its mineralogical contents were determined by X-ray diffraction and thermogravimetry analysis, and its micro-morphology was studied by scanning electric micrograph analysis. The results show that DSF ash has a higher CaO and SO3 content, and the main sulfur form is sulfite, with only a part of it oxidized to sulfate. The major minerals present in DSF ash are hannebachite, anhydrite, calcite and portlandite; a minor constituent is calcium chloride. The particles of DSF ash are irregular, fragmentary and small, and hannebachite grows on their surfaces. Particle size is affected by the FGD process, and the ash size from the maximized emission reduction of the sintering-FGD process is lower than that from the circulating fluidized bed-FGD process. The particle size distribution of DSF ash follows the Rosin--Rammler-Bennet equation.
脱硫（FGD）系统飞灰的特性对其再利用很重要，主要取决于脱硫工艺。研究了铁矿石烧结过程干法 FGD 系统飞灰（简称 DSF 灰）的物理化学性质。采用 X 射线衍射和热重分析测定了其矿物含量，通过扫描电镜分析研究了其微观形貌。结果表明，DSF 灰具有较高的 CaO 和 SO3 含量，主要的硫形态为亚硫酸盐，只有一部分氧化为硫酸盐。DSF 灰中的主要矿物有钙矾石、硬石膏、方解石和氢氧化钙；少量的氯化钙。DSF 灰的颗粒不规则、破碎且小，钙矾石生长在其表面。颗粒尺寸受 FGD 工艺的影响，烧结-FGD 工艺最大减排的灰粒径小于循环流化床-FGD 工艺。DSF 灰的粒度分布符合罗辛-拉姆勒-本内特方程。
