Filling of Nanocarbon Particles in the Pores of Unburned Carbon and Its Application in Gasification Ash Separation

Abstract

The nanocarbon particles and diesel are used as hydrophobic solid particles and the liquid phrase to produce the mixture collector for the flotation separation of unburned carbon (UC) particles from gasification ash. Scanning electron microscopy/energy-dispersive spectrometry and mercury porosimeter measures were used to prove the filling of nanocarbon particles in the pores of UC particles. Mercury porosimeter results illustrate that the pores of the UC particles after the action of the mixture of nanocarbon particles and diesel are reduced compared with that after the action of diesel. The number of >4000 nm pore was significantly reduced, and the number of <250 nm pore nearly disappeared. The results of the flotation tests found that the use of the mixture of nanocarbon particles and diesel as a collector resulted in not only increasing the concentrate yield but also reducing the ash of the concentrate. Throughout this investigation, the filling of nanocarbon particles in the UC holes/pores plays an important role in the enhancement of flotation recovery of UC particles. The filled pores in the UC particle surface can increase the contact area between bubbles and UC particles, thereby increasing the adhesion of bubble-particles, reducing the probability of particle detachment, and ultimately improving the flotation recovery of UC.