浸出(土壤学)
氟化物
电解质
浸出剂
扫描电子显微镜
材料科学
核化学
化学
冶金
无机化学
硫酸
复合材料
电极
环境科学
物理化学
土壤科学
土壤水分
作者
Perseverance Dzikunu,Emmanuel Kwesi Arthur,Emmanuel Gikunoo,Elike Bleppony,Frank Ofori Agyemang,Kwadwo Mensah‐Darkwa
标识
DOI:10.1016/j.psep.2022.11.008
摘要
Spent pot lining (SPL) is a hazardous by-product obtained during the decomposition of carbon cathodes in the electrolytic cells used in aluminium smelting. The carbon cathode lining materials degrade over time thereby affecting the performance of the electrolytic cell. Fluoride contents of up to 20 wt% and cyanides up to 1 wt% have been reported as the main environmental concerns in SPL. This study investigated the effect of successive selective leaching (SSL) of pollutants from the SPL in obtaining suitable carbon for use in energy storage applications. Compositional and microstructural analyses were performed on the leached and as-received SPL samples using X-ray fluorescence spectroscopy (XRF), transmission electronic microscopy – energy dispersive X-ray (TEM-EDX), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. In this study, the XRD analysis revealed that fluoride ions in the SPL exist as sodium fluoride (NaF) and calcium fluoride (CaF2). The results indicated that the SSL of SPL is dependent on pH, temperature, types of lixiviant used for the selective leaching and number of washings. It was established that increasing the number of washings with steady stirring rate reduced electrical conductivity and fluoride concentration in the filtrate. Furthermore, high ion removal was achieved at 100 ℃. The current study therefore demonstrated successful removal of pollutants such as CaF2, SiO2, NaF, Al2O3 and Na3Al11O17 while providing insight into the chemical structure and morphology of the treated and untreated SPL.
科研通智能强力驱动
Strongly Powered by AbleSci AI