Dewatering of fine coal — micrographic analysis of filter cake structure

Dewatering effect of fine coal slurry and filter cake structure based on particle characteristics

“…The effects of driving force, solid concentration, filter area, particle size and slurry pH on dewatering behavior were studied, and the best filtration enhancements were achieved by the addition of oils [8,9]. It was also found that the rate of dewatering and moisture content of the filter cakes were directly related to the particle size [10,11]. In the studies of Zhang [12], wet mass to dry mass, specific resistance of average mass, compressibility factor and microstructure of filter cake accounted for the reasons and mechanisms of fine clean coal efficient dewatering.…”

Effect of froth stability on dewatering of coal flotation concentrates

“…The dewatered cakes were consolidated by impregnation in which methyl ethyl ketone (MEK) was allowed to pass through to displace the remaining water. This enabled the successful bonding of epoxy resin to the inner coal structure at the subsequent stage (Kakwani et al , 1985; Chi et al , 1985; Zhu, 1997). A hardener was mixed with the resin to have a suitable setting time.…”

“…When the solid concentration is high, particles have less time to segregate during the cake formation period, producing a cake with a more uniform structure and less specific cake resistance. Consequently an increase in solid density reduces the final cake moisture (Sung and Turian, 1994; Kakwani et al , 1985). In addition, the final cake moisture is dependent on the applied vacuum pressure.…”

“…The homogeneity of cake layers is also an important parameter determining dewatering characteristics. A narrow size distribution produces a more uniform cake structure than a wider size distribution due to less specific cake resistance created by the more uniform cake (Sung et al , 1994; Kakwani et al , 1985). The coal slurry concentration can affect the cake homogeneity as well by influencing the degree of coal particle segregation.…”

“…In addition, the final cake moisture is dependent on the applied vacuum pressure. An increase in the applied vacuum pressure in filtration increases the rate of filtrate flow through the filter, therefore reducing the final cake moisture (Kakwani et al , 1985; Le Roux and Campbell, 2003). Raising slurry temperature also lowers the final cake moisture by reducing the viscosity of the slurry, thereby increasing the filtrate flow rate (Wakeman, 1984).…”