Papers by Shobhana Dey Scientist Nml
International Journal of Coal Preparation and Utilization, 2012
ABSTRACT The low volatile medium coking coal fines from the eastern part of Indian coalfield was ... more ABSTRACT The low volatile medium coking coal fines from the eastern part of Indian coalfield was used for this study. The proximate analysis of the composite sample designates that the fines contain about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The ash in the size fraction of -0.5 + 0.15 mm is lower (21.9%) than the -0.15 mm fraction (29.7%). The flotation characteristic of the composite coal reveals that recoverable combustible at 15% ash is 27% and 43% at 17% ash level. The low yield of the concentrate is due to the presence of fines comprising high ash. To enhance the yield the -0.5 + 0.15 mm and -0.15 mm fractions were subjected to flotation separately. The effects of reagent dosage and aeration rate were studied with composite and -0.5 + 0.15 mm fraction to produce low ash clean coal. Release analysis carried out with -0.5 + 0.15 mm improves the recovery of combustible to 42% at 15% ash%. The spilt flotation of -0.5 + 0.15 mm feed at the lower frother dosage and lower aeration favours to generate the clean coal with low ash. The -0.15 mm fraction was floated with collector using sodium silicate as depressant. The products having different ash level could be used in specific purposes.
International Journal of Coal Preparation and Utilization
The low-volatile medium coking coal fines from the eastern part of the Indian coalfield was used ... more The low-volatile medium coking coal fines from the eastern part of the Indian coalfield was used for this study. The proximate analysis of the composite sample designates that the fines contain about 25% ash, 21.4% volatile matter, and 52.4% fixed carbon. The ash in the size fraction of −0.5 + 0.15 mm is lower (21.9%) than the −0.15 mm fraction (29.7%). The flotation characteristic of the composite coal reveals that recoverable combustible at 15% ash is 27% and 43% at the 17% ash level. The low yield of the concentrate is due to the presence of fines comprising high ash. To enhance the yield, the −0.5 + 0.15 mm and −0.15 mm fractions were subjected to flotation separately. The effects of reagent dosage and aeration rate were studied with a composite and the −0.5 + 0.15 mm fraction to produce low-ash clean coal. Release analysis carried out with −0.5 + 0.15 mm coal improves the recovery of combustibles to 42% at 15% ash%. The spilt flotation of −0.5 + 0.15 mm feed at the lower frother dosage and lower aeration favors generating the clean coal with low ash. The −0.15 mm fraction was floated with collector using sodium silicate as a depressant. The products having different ash levels could be used in specific purposes.
Separation Science and Technology, 2012
In India, iron ores processing industries play a vital role in the Indian economy. During the was... more In India, iron ores processing industries play a vital role in the Indian economy. During the washing and processing of iron ores, slimes less than 0.15 mm are generated and discarded into the tailing pond. These slimes need processing as they cannot be used directly in blast furnaces. In the present investigation, a typical iron ore slime sample containing 59.22% Fe, 4.76% SiO2, and 4.57% Al2O3 was taken. The desliming operation was carried out by using 2” Mozley hydrocyclone. The process variables used to attain the optimum condition of desliming include the spigot opening, the feed pressure, and the diameter of the vortex finder maintaining the pulp density at 10% solid. The deslimed sample was treated by different techniques including an enhanced gravity separator to achieve iron concentrate with 65% Fe so that it can be used for steel making through pelletization. The yield of the magnetic concentrate is about 46.8% with 65% Fe. To improve the yield, the overflow from 2” hydrocyclone and the rejects from magnetic separation were deslimed and processed to recover the iron values. The final concentrate is 74% yield with 64.8% Fe, 1.76% SiO2, and 1.8% Al2O3.
Uploads
Papers by Shobhana Dey Scientist Nml