Effects of Typical Components on Physicochemical Properties of Refining Slag and Sulfur Migration Enhanced by Electric Field

摘要

The removal of sulfur impurities from refining slag by external electric field is an important research direction of metallurgical solid waste recycling. In this study, Fourier transform infrared spectrometer, Raman spectroscopy, X-ray diffraction analyzer, rotating viscometer, and four-electrode conductivity tester were used to obtain the relationship between composition, structure, and properties of CaO-SiO2-Al2O3-MgO-CaF2 refining slag system. The effect of slag properties on the transfer efficiency of sulfur element enhanced by electric field was analyzed based on pulsed electric field experiment. The results showed that, when CaO/Al2O3 ratio changed from 1.2 to 2.0, the depolymerization of slag network structure and the disappearance of high-melting-point phases made the viscosity to decrease and the electrical conductivity to increase. When the MgO content changed from 4 to 12 wt%, under the influence of slag network depolymerization and the precipitation of high-melting-point phases, the viscosity decreased first and then increased, and the electrical conductivity trend was opposite. With the increase of F- content in the range of 3-7 wt%, the viscosity decreased first and then increased due to the depolymerization of slag network structure and the bonding of excess F- irons, and the electrical conductivity trend was opposite. According to the sulfur migration in refining slag, 0.5 h was determined as the suitable time parameter of applied electric field. When the voltage was 0-4 V, the electric field and the simplification of slag network structure can obviously promote the sulfur removal from slag. When the voltage was 6 V, the sulfur element in slag increased with the increase of CaO/Al2O3 ratio, and one reason was an increase in electrical resistance. [GRAPHICS] .