A Sustainable Strategy for Spent Cathode Carbon Blocks Hazardous Waste Recycling Using Binary Molten Salt Thermal Treatment  

作　　者：LI Bin DING Yan JIAO Yuyong XU Fang WANG Xinyang ZHENG Fei ZOU Junpeng GAO Qiang HU Hongyun 

机构地区：[1]Faculty of Engineering,China University of Geosciences,Wuhan,430074,China [2]Institute for Natural Disaster Risk Prevention and Emergency Management,China University of Geosciences,Wuhan,430074,China [3]State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan,430074,China

出　　处：《Journal of Thermal Science》2024年第3期1082-1093,共12页热科学学报（英文版）

基　　金：supported by the"CUG Scholar"scientific Research Funds at China University of Geosciences(Wuhan)(Project No.2020088);National Natural Science Foundation of China(No.41920104007);Opening Fund of State Key Laboratory of Fire Science,University of Science and Technology of China(No.HZ2023-KF03)。

摘　　要：Waste-to-Energy treatment is a promising path to environment and energy management in the future.This work detailed a binary molten salt thermal treatment methodology for the detoxification of spent cathode carbon block(SCCB)waste and the recycling of carbonaceous materials.The thermal behavior of SCCB and SCCB blended with molten salts was investigated.It was found that the NaCl-Na_(2)CO_(3)binary molten salts significantly contributed to reducing pyrolysis onset temperature by 334.3 K compared to that of SCCB itself(i.e.,activation energy of pyrolysis reaction was reduced from 4.24×10^(5)to 2.30×10^(5)J/mol),thus helping to lower thermal treatment energy consumption.With the addition of binary molten salts,the residue after thermal treatment in a horizontal tube furnace experiment was separated into two layers.The bottom-layer residue was mainly composed of molten salts.The fluorine content in the form of NaF and CaF_(2)of top-layer residue was reduced significantly while the carbon content remained unchanged.Specifically,the leaching concentration of fluoride ion was decreased from 4620 mg/L to 856 mg/L.It is noted that the NaF and CaF_(2)can be removed through water-leaching and hydrothermal acid-leaching methods and thus the carbonaceous materials with a calorific value of 17.5 MJ/kg were obtained.

关 键 词：spent cathode carbon block hazardous solid waste DETOXIFICATION binary-molten-salt thermal treatment carbon recycling pyrolysis kinetics 

分 类 号：X758[环境科学与工程—环境工程]