Deep tellurium refinement: improvement of equipment and technology using process simulation

Abstract

Simulation data have been presented on tellurium deep refinement process based on refinement technique developed by the Authors and implemented on the basis of analysis of the thermodynamical condition of the process unit using the FlowSimulation software from SolidWorks. The technique suggested herein has been implemented in a plant having a vertical air-tight reactor arranged inside a multi-zone thermal unit and providing for a combination of sequential refinement stages based on different techniques and integrated in a single process. The calculations are based on experimental data which have allowed one to determine the boundary conditions of the mathematical model using previous experience of work with the abovementioned software product. The temperature profiles have been calculated taking into account all the types of heat transfer in the system, the weight and dimensions of the system components and the physicochemical properties of refined tellurium, materials of reactor fittings and reactor media. The boundary conditions for the thermal calculations have been the temperature modes of process stages with specific known temperatures at local points of reactor fittings where temperature gages connected to a PID controller have been installed. During the simulation of specific process conditions for the refinement technique, process modes and design of equipment fittings components have been corrected. The Authors have developed and fabricated test models of the process and imitation equipment, and analysis of the thermal fields for the final model has shown good agreement with the mathematical model. Equipment upgrading and process parameter correction on the basis of the simulation results have allowed T-udo Grade tellurium to be refined to a 99.99992 wt.% purity by 30 main impurities with a product yield of at least 60% in the course of physical experiments.