A NOVEL SOLVENT EXTRACTION PROCESS WITH BOTTOM GAS INJECTION FOR LIQUID WASTE TREATMENT

摘要

A novel solvent extraction process in which theemulsion is generated by bottom gas injection rather thanmechanical stirring has been developed. This process has anumber of advantages over the mixer-settler unit or the spraycolumn in terms of simple equipment configuration and the easeof cleaning and process control while providing a largeinterfacial area for mass transfer. The equipment consists of ahorizontal cylindrical vessel in which the two immiscible liquidsflow countercurrently. High-strength gas jets are injected fromthe bottom at certain intervals along the length of the vessel. Thegas jet creates a plume zone consisting of an emulsion of thetwo liquids which contains a large interfacial area for rapid masstransfer. The two liquids then disengage and flow in the oppositedirections before entering another plume zone. Thus, the processcombines the simplicity of a cylindrical vessel, having nomoving parts, with the contacting efficiency of a mixer-settler.The gas can be recycled in a closed loop, thus eliminating mistand other emission problems. These advantages would beespecially significant for treating large-volume/low-value liquidstreams which contain hazardous substances and/or suspended solid particulates.