Beneficiation of an Indian non-coking coal by column flotation

Abstract

Beneficiation of non-coking coal is gaining ground in India. It not only reduces the volume of inert content to be transported to the power plant and also lowers the wear in the boiler houses. For special applications such as the fuel for integrated gasification combined cycle plant (IGCC), the ash content in the coal should preferably be below 15 %. Indian coals are characterized by high inter-grown ash content mainly due to 'drift origin' of Gondwana formation in Permian age. This warrants fine grinding of non-coking coal in order to liberate the ash forming minerals from coal macerals. A noncoking coal sample of vitrinite type from India was ground to 44 lm (d 80 ) and subjected to column flotation to improve its quality. The non-coking coal analyzing 34.6 % ash, 26.2 % volatile matter, 1.3 % moisture and 37.9 % fixed carbon could be upgraded to a concentrate/froth of 14.83 % ash at 72.18 % yield by optimizing collector and frother dosages and flotation column operating parameters, namely, froth depth, superficial feed velocity and superficial air velocity. The concentrate produced by this process is suitable as fuel for IGCC in coal-to-electricity route.

Negative-pressure pneumatic separator: a new solution for hard-coal beneficiation

“…Various enrichment techniques have been developed over the past century, and among them, wet methods are most commonly used, owing to their high precision (Infomine Research Group 2015). Coal-processing technology is being continuously developed with the implementation of new solutions and improvements to existing ones (Galvin et al 1999;Nguyentranlam and Galvin 2001;Galvin et al 2002;Honaker et al 2007;Sarkar et al 2008;Das et al 2009;Honaker et al 2010;Hacifazlioglu 2012;Vasumathi et al 2016). Currently, the largest coal recipients, i.e.…”

Fine coal beneficiation by pilot column flotation

“…The main advantages of the column flotation cells over mechanical ones include excellent separation ability, low capital and operating cost, a less demand for plant space, simple circuit and efficient selfcleaning and adaptability to automatic control [8,14]. Also, the performance of the column is superior to that of conventional cell owing to the presence of large fines in the coal [15][16][17]. Upgrading of coal in a flotation column can be significantly improved when froth stability is properly controlled through the manipulation of appropriate variables such as gas flow rate, froth height and feed solid concentration [18].…”

Determination of optimal flotation conditions of low-grade graphite ore

“…Flake graphite is assumed to be derived from finegrained sediments rich in the organic matter. As metamorphic grade increases, carbonaceous material converts to amorphous graphite [3,6]. Flake graphite is classified based on the size of the crystal flakes and graded according to their graphitic carbon content and particle size.…”

“…Flake graphite is classified based on the size of the crystal flakes and graded according to their graphitic carbon content and particle size. Microcrystalline graphite is commercially called amorphous graphite [6].…”

“…Pine oil and methyl isobutyl carbinol are used as frothers and sodium silicate, quebracho and starch are used to depress gangue minerals. Optimum pH in graphite flotation is between 8 and 9 [8,11].The polyethylene oxide type frothers such as polyoxyproplene glycol butyl ether were also studied as a replacement for MIBC in graphite flotation [6,14]. Flotation is carried out in different stages ranging from two to several, depending on the liberation characteristics of the ore to be treated [2].…”