Research progress on comprehensive utilization of flue gas desulfurization gypsum and gypsum slag in smelting industry
PAN Zu-chao, JIAO Fen, QIN Wen-qing, ZHANG Tian-fu, RUAN Bo-wen
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The Flue gas desulfurization process of coal-fired power plants and the neutralization process of smelting acid wastewater are accompanied by the generation of solid waste with calcium sulfate dihydrate as the main component. The former is called flue gas desulfurization gypsum (FGDG), while the latter is usually called gypsum slag. FGDG has been used in many ways such as building materials, production of chemical raw materials, environmental treatment, and soil remediation. It is difficult to use gypsum slag because it contains arsenic, copper, lead, chromium, and other harmful elements. The usual treatment methods are solidification/stabilization treatment, high temperature melting treatment, recovery of valuable metals, and slagging agent.This paper analyzes the advantages and disadvantages of disposal and utilization technology, discusses some problems and deficiencies existing in the application, and puts forward some suggestions.The future research should focus on FGDG minimization, expanding the high value utilization scale, and developing high value-added products to improve the comprehensive utilization rate. The technologies of harmless and resource utilization of gypsum slag, such as calcium sulfate crystal regulation, pyrometallurgical-wet synergistic treatment,and using as slagging agent are the future development directions.