Beneficiation of Indian coal by chemical techniques

Demineralization mechanism and influence of parameters on high ash Indian coal by chemical leaching of acid and alkali solution

“…The ammonia (NH 3 ) treated coal was reacted with the mixture of concentrated sulfuric acid and calcium fluoride in a two-stage process at temperature 350°C. Low demineralization (13%) was obtained in the two-stage process in comparison to only ammonia-treated coal and 70% demineralization was achieved (Choudhury and Bhaktavatsalam 1997). Nabeel et al studied sequential leaching of power grade coal with NaOH-H 2 SO 4 and obtained more than 50% degree of demineralization and also regenerate the leachate by treated with lime and silicic acid (Nabeel et al 2009).…”

Application of a system dynamics approach for assessment and mitigation of CO2 emissions from the cement industry

“…Coal consumption for power generation, taken as a level variable, is calculated and projected for a span of 20 years. For estimating the availability of fly ash it is assumed that on an average the Indian coal has 33% ash content (Mehra and Damodaran, 1993;Choudhary and Bhakatvatsalam, 1997; www.cea-in/opt7-vidyut-chap4.html). Out of this 80% comes out as fly ash during coal combustion in thermal power plants.…”

Effect of elevated temperature and pressure on the leaching characteristics of Indian coals

“…Researchers and scientists around the world have tried out many such processes [11]. Araya et al [12] observed increase in desulphurisation and demineralisation of a sub-bituminous coal with reaction time, temperature and concentration of sodium hydroxide solution.…”