A New Technique for Removing Unburned Carbon from Coal Fly Ash at an Industrial Scale

作者：Guosheng Li, Lijun Deng, Jiongtian Liu, Yijun Cao, Haijun Zhang, Jincai Ran · 发表于：International Journal of Coal Preparation and Utilization · 年份：2015 · DOI：10.1080/19392699.2015.1008098 · 被引用次数：23 · 研究领域：Minerals Flotation and Separation Techniques、Mineral Processing and Grinding、Metallurgical Processes and Thermodynamics

Removal of unburned carbon from the high-carbon fly ash (HCFA) is essential when it is used as an admixture in cement concrete. This article deals with processing of the HCFA from the Guangdong province of China. A cyclonic-static microbubble flotation column (FCSMC), a novel device with the characteristics of internal recycling process and multiple mineralization steps, was used to separate unburned carbon from ash materials. A commercial flotation plant with a handling capacity of 110 ton coal fly ash (dry basis) per hour was set up. Using the optimum operational parameters, a clean ash with loss on ignition (LOI) of 3.08% and a removal rate of unburned carbon (RUC) of 80.41% was obtained. The calorific value of the unburned carbon products reached 3534 cal/g. Industrial-scale flotation tests on the circulation pulp pressure demonstrated that the energy input mode and internal recycling process of FCSMC separator was effective in removing unburned carbon from HCFA.