Distribution characteristics and separation experiment of carbon ash from coal water slurry gasification fine ash

The distribution characteristics and separation of carbon and ash in high concentration coal water slurry entrained flow gasification fine ash prepared by three peak grading technology were studied. The physicochemical properties of fine ash were analyzed by SEM-EDS (scanning electron microscope energy dispersive spectrometry),XRF (X-ray fluorescence spectroscopy),XRD (X-ray diffraction) and bet (surface and porosity analysis). The carbon and hydrogen in coal were determined by the determination method the carbon content of gasification fine ash was tested and the results were analyzed. The basic characteristics of gasification fine ash and carbon ash distribution law were obtained. The carbon ash separation method of gasification fine ash was explored by using conventional flotation test method in laboratory. The results show that under the conventional flotation conditions,the fine ash with ash content of 47.98% can obtain flotation concentrate with yield of 14.95% and ash content of 45.53%. The main reason for the poor conventional flotation effect is that most of the organic matter of raw coal is transformed into gas products after gasification,some non-combustible minerals are melted,enriched and transformed in the fine ash,and the collector only has physical adsorption when it is easy to contact with the mineral surface,resulting in the mineral particles on the surface of the fine ash will react with the collector The fine ash has developed pore structure,large specific surface area and pore volume,and will inhale a lot of water and flotation reagents,which not only makes the particle surface hydrophilic and not easy to float,but also consumes a lot of reagents; the carbon ash distribution characteristic of fine ash is that the ash content gradually increases with the decrease of particle size,which can be determined by particle size classification The high carbon fine ash with 79.78% carbon content and 54.20% yield can be obtained when the classification size is 0.1 mm.