Split flotation of LVMC coal to generate multiple products for complete utilization

Dey, Shobhana and Pani, Santosh and Das, Avimanyu (2012) Split flotation of LVMC coal to generate multiple products for complete utilization. In: International Mineral Processing Congress,2012, 24-28 Sept 2012, New Delhi.

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Abstract

A low volatile medium coking coal from Jharia coal field, India was used for this investigation. The proximate analysis of the sample shows that it contains about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The sizewise ash analysis of -0.5 mm coal indicates that -0.5+0.15 mm fraction contains lower ash (21.9%) than -0.15 mm fraction (29.7%). The flotation characteristics of the -0.5 mm coal were determined by release analysis. The study reveals that recovery of combustible at 15% ash is about 27% and 43% at 17% ash level. The low recovery is due to the presence of high ash in finer fraction. In order to improve the recovery, the -0.5 mm feed was classified into -0.5+0.15 mm and -0.15 mm fractions, and subjected to flotation separately. The recoverable combustible obtained from the release analysis of -0.5+0.15 mm at 15% ash level is 46%. The effect of collector dosage, frother dosage and aeration rate on flotation was studied. The responses of these variables in collectorless flotation of the -0.5+0.15 mm fraction containing low ash were also studied. A lower aeration and frother dosage favored the generation of clean coal with low ash. The ash content in the tailing stream from -0.5+0.15 mm flotation circuit is close to that of the original -0.15 mm fraction. The former is ground to -0.15 mm and the two fractions are processed together. As -0.15 mm fraction contains relatively higher ash, collector aided flotation using sodium silicate was performed to recover the clean coal with 17% ash. The products of the overall flotation circuit having different ash levels were recommended for use in different applications. The reject from -0.15 mm flotation circuit contained 56.4% ash which can be used for fluidized bed combustion (FBC). This eventually leads to complete utilization of coal.

Item Type:Conference or Workshop Item (Paper)
Official URL/DOI:http://eprints.nmlindia.org/6552
Uncontrolled Keywords:flotation, air flow rate, reagent dosage, bubble size, stability of froth
Divisions:Mineral Processing
ID Code:6552
Deposited By:Dr. Shobhana Dey
Deposited On:19 Apr 2013 10:54
Last Modified:19 Apr 2013 10:54
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