Study On Interfacial Layer Characteristics Of Organic Coated Solids In FCC Slurry

FCC slurry contain 40⁶0 wt%aromatic hydrocarbons,which can be used to prepare high value-added productions,such as needle coke,carbon black,and rubber filling oil,etc.The solids in slurry will affect the utilization of slurry,thus it is necessary to pretreat to separate the solids before the utilization of slurry.The common methods used in removing solids from slurry,such as filtration and electrostatic separation,whose removal efficiency is closely related to the composition of organic coated solids.Therefore,it is of great importance to study the interfacial characteristics of organic coated solids in slurry,such as composition of organic coated solids,to guide the removal of solids.In this paper,Liao He slurry was used as the raw material.Three kinds of solids with different particle size distributions in slurry were sequentially enriched by low speed centrifugation and oil-water interfacial method.The optimum conditions for enrichment were explored.The organic coated layer was gradually extracted by solvents.The compositions of three kinds of organic coated solids and bulk solids before and after solvent extraction were analyzed.The structure characteristics of organic coated layer were studied.This will provide theoretical basis for the removal of solids in slurry.It is found that the organic coated solids are consist of bulk solids and interfacial layer.The organic coated solids observed by optical microscopy are spherical particles with particle size distribution of 8³5?m.Bulk solids are agglomerated by ultrafine particles consisting of small spherical and rod like particles with particle size distribution of 5¹850 nm.The composition of interfacial layers from outside to inside is nonpolar long chain n-paraffin with chemical formula is C₃₁H₆₄,aromatic hydrocarbons with long chain alkyl,naphthenic group,alkenyl group and heteroatom,polar short chain aromatic hydrocarbons.