Research On The Basis Of Chromite Reduction By Silicon Thermal Reduction And The Separation Process Of Slag Gold In A Microwave Field

Compared with traditional heating,microwave heating has the characteristics of fast and uniform heating,selective heating,easy control,clean and pollution-free.Currently,microwave heating technology has been extensively studied in metallurgy,and some have been industrialized.Aiming at the problems of short life of smelting equipment,high smelting temperature and long smelting time in the traditional low-carbon ferrochromium alloy smelting technology,a new siliconthermic reduction chromite process in the microwave field was developed.But little basic research is available to siliconthermic reduction chromite in the microwave field.In this paper,the reaction thermodynamics and kinetics of smelting low-carbon ferrochromium alloy by siliconthermic reduction chromite under the condition of conventional heating and microwave heating were studied.The microscopic analysis of the slag-metal separation process of product,which has important of guiding significance for the development of smelting low-carbon ferrochromium alloy technology in the microwave field.The research contents and conclusions of this paper are as follws:1.The absorption and dielectric characteristics of chromite powder and ferrosilicon powder were studied.The research results show that chromite powder,ferrosilicon powder and mixture have good wave absorption properties,and the ferrosilicon powder is more effective for microwave energy than chromite powder;Chromite powder,ferrosilicon powder,and mixture can be heated rapidly to 1200?in the microwave field,and the heating speed is:ferrosilicon powder>chromite powder>mixture.2.The thermodynamic analysis,thermogravimetric analysis and kinetic analysis of silicothermal reduction of chromite were studied.conditions,Iron oxides are reduced prior to chromium oxides during siliconthermic reduction in the condition of the microwave heating.The reduction of iron oxides follows the reduction sequence of Fe₂O₃?Fe₃O₄?Fe O?Fe.The reduction of Cr₂O₃follows the reduction sequence of Cr₂O₃?Cr O?Cr,which is consistent with conventional heating.The kinetic analysis show that the apparent activation energy of conventional reduction is 82.933 k J/mol,while the apparent activation energy of microwave reduction is 53.849 k J/mol,147.231k J/mol,22.027 k J/mol.It's significantly reduced the apparent activation energy.3.The process of slag-metal separation of conventional and microwave siliconthermic reduction chromite was comparatively researched.The results show that different heating methods have effects on the phase and microstructure of siliconthermic reduction products.When microwave siliconthermic reduction chromite,the types of new phases produced are less than conventional heating,the metal phase is more uniformly distributed,cracks will appear on the surface of the solid particles during the reduction process,when the reduction temperature is 1300?,the metal phase and the slag phase There will be clear boundaries.