Effective Chemical Leaching and Ash Depletion of Low Rank Coal with EDTA and Citric acid

both physical and chemical methods are in practice to clean the coal and reduce its ash content. Mineral acids are used as chemical leachants, but because of their strong oxidizing power, they might have some disadvantages. In the presents research work, demineralization of low grade coal with mild chemical leachants like EDTA and citric acid were studied. They were found as effective as mineral acids like HCl, HNO, HF etc. they may be considered as preferred alternatives of the acids because Energy Dispersive X-rays Spectrophotometry (EDX) study has revealed that EDTA and citric acid leaching do not harm the carbon content of the coal as the acids did Moreover, the environmental hazards due to use of acids may be avoided. In the current research, the coal samples were leached with HCL, HNO3, CH3COONH2 acid mixture (H2O, HCl, HNO3 and HF) EDTA, buffered EDTA and citric acid. The treated coals were investigated for elemental analysis with EDX. The digestates of the ashes of treated coals were studied for metal contents with the help of Atomic Adsorption Spectrophotometer (AAS) to be high volatile lignite based on its Proximate and Ultimate analyses effectuated. The mild leachants investigated in the currents research will be helpful to utilized low rank coals in an environment friendly way deletratious effects associated with their combustion. 

U KHAN ,H ULLAH ,M ISHAQ ,M SHAKIRULLAH ,H REHMAN ,I AHMAD ,