Mechanistic study on the structural evolution of coal gasification fine slag during coupled activation-acid leaching
SUN Zhenjie
TANG Biao
DONG Kaiming
WU Songtao
YOU Xiaodong
HUANG Xiaoyang
LIU Yuan
ZHANG Hao
TIAN Baiqi
GUO Feiqiang
Abstract：Coal gasification fine slag(CGFS)is an inorganic solid waste rich in Si,Al,and car-bon resources.However,the aluminosilicate-derived glass phase in CGFS demonstrates chem-ical inertness and encapsulates a large number of metal elements,severely restricting efficient resource recovery and limiting its potential high-value applications.In this work,a coupled Na2CO3 activation-acid leaching process was developed for enhanced Si and Al extraction from CGFS.The effects of activation temperature,duration,and m(CGFS)/m(Na2CO3)ratio on the leaching efficiencies of Al and Si were systematically investigated.The results show that under optimal conditions of 850℃,m(CGFS)∶m(Na2CO3)=1∶1,and 60 min activation,leaching efficiencies of 95.65％for Al and 52.48％for Si have been achieved.Multiple charac-terization methods were employed to analyze the structural evolution of CGFS during activation and acid leaching.The results show that Na2CO3 activation effectively disrupt the glass phase in CGFS,releasing the encapsulated metal elements and partially transforming some phases in-to acid-soluble nepheline(NaAlSiO4),thereby significantly improving the efficiency of subse-quent acid leaching.After acid leaching,the specific surface area of the sample increase signifi-cantly from 94.53 m2/g to 462.81 m2/g,with the formation of abundant microporous and me-soporous structures.Consequently,the Na2CO3-activation enhance acid leaching process proves highly effective in improving the extraction of Si and Al from CGFS.
Keywords：coal gasification fine slagactivationenhanced acid leachingelement leaching ra-tiostructural evolution
Publication Date：2025-05-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 524-533 )