3D Simulation And Design On Big Current Rare Earth Electrolytic Cell

Rare earth molten salt electrolytic cell is mainly used for producing single rare earth metals and rare earth alloy.A kind of high current rare earth electrolytic cell is designed in this paper for traditional low current rare earth electrolytic cell can't meet large-scale production requirement,which not only can meet the market demand for single rare earth metals,but also can solve the problems of scattered distribution and bad electrolysis property in small-sized electrolytic cell.This paper takes the 15 KA rare earth electrolytic cell an design research objective which is needed in national ion-type rare earth resource high efficient development engineering research center.The groove design and structure parameters correction in electrolytic cell were obtained through aided simulation design software with some known parameters,the specifics as follows:(1)According to design demands to make a research on high current electrolytic cell type,the structural shapes of 15 KA electrolytic cell is confirmed.The size range of cathode and anode in electrolytic cell can be calculated by parameters such as known total current and current density.Using Solid Works to establish 3-D model of each part in electrolytic cel,finally complete the whole model.(2)Using finite element analysis method to simulate 3-D electric field in rare earth electrolytic cell.The results show that the distribution of electric cell can be divided into cathode area,anode area and crucible metal collecting area.The electric potential in anode area is almost equal.Electric potential lines in cathode area are the most densest,and current flows from anode to cathode.In the metal collecting area,the electric potential difference is very small and potential lines is relatively sparse.The simulation results in 3-D electric field is verified by comparing with the previous 2-D electric field distribution in transverse and vertical.And then studies of the impact of distance(a)from electrode to the bottom and polar distance(b)on electric field distribution in electrolytic cell were obtained,and according to the parameter that got in the simulation,the relational expressions of the melt voltage V and parameter a in a certain polar distance b was calculated,so was the relational expression of current density D and parameter a.Through taking the biggest current density as a optimization objective and cell voltage needed in operation process as a reference target,the optimum parameters of a and b were obtained.(3)Using COMSOL Multiphysics electro thermal coupling module,the thermal field distribution in electrolytic cell was obtained through applying electric field and thermal field boundary.The result show that high temperature only distribute around circular arch anode and its faced cathode,which is not unreasonable.Then each physical field of equipping three cathodes in electrolytic cell was gotten under the same condition,and the results was compared with equipping four cathodes,finally the rationality of equipping four cathodes was verified.Changing the distance of centers of circle(d)from half circular arch anode to its faced cathode,the optimized parameter d with the best thermal field distribution that can meet electrolysis demand was obtained.Under the optimized parameter(d)the high temperature area distributes around the middle part of each cathode,and temperature in other area decreases uniformly from high temperature area to nearby area at a certain gradient.Finally the changing of cathode shape at electrolysis process caused by high current density was analyzed.The result showed that cathode was eroded as cone from bottom circle edge,the maximum current density in the electrolytic cell was increased with erosion cathode,which is corresponding with actual production.(4)According to the project requirements,the shape parameter design of 15 KA rare earth electrolytic cell were accomplished.Specific production process of rare earth electrolytic cell is briefly introduced,which including the manufacture of bottom insulating layer,cross beam and shores,installation of the outer shell,masonry of inside insulating brick of the outer shell,installation of internal and external protective case,graphite groove,furnace cover plate,anode electro conductive plates,and cathode lifting platform.With physicochemical index analysis and selection of materials needed in partial manufacture,the whole rare earth electrolytic cell was finally finished.