| The paper briefly introduces the development history and current situation of magnesium smelting industry at home and abroad. Pointed out researching the new magnesium smelting process is the key to promote the development of magnesium industry and is an effective method to solve the existing problems of traditional magnesium industry. Especially, researching the process of production magnesium by vacuum carbothermal reduction of magnesia is very important. From the development history of magnesium smelting industry, we know metallurgical equipment is the basis of the development of Magnesium smelting process, and the improvement and innovation of metallurgical equipment will promote greatly the development of Magnesium smelting process. Therefore, it was of great significance to design a new and advanced metallurgical furnace for the process of production magnesium by vacuum carbothermal reduction of magnesia.Thermodynamic calculation gives that: it is feasible to product magnesium by vacuum carbothermal reduction of magnesia. Some small-scale experiments have been conducted of vacuum carbonthermal reduction of magnesia by Kunming University of Science and Technology Vacuum Metallurgy and Materials Institute, and have achieved some productions. In order to further study the reaction mechanism of vacuum carbon thermal reduction of magnesium and resolve the existing problems of traditional magnesium smelting process, such as large energy consumption, environment pollution, poor safety operation, time consuming, high cost. On the basis of predecessor's experiments, domestic and foreign literature and the various vacuum metallurgical furnaces in Vacuum Metallurgy and Materials Institute, author designed a new type of vacuum furance to carry on the medium-sized extension experiment of vacuum carbon thermal reduction of magnesium. And hope that some existing problems of traditional magnesium smelting process to be resolved effectively and gain the best process parameters to provide a scientific basis for industrialization in the future.The new vacuum metallurgical furnace consists from the heating system, the vacuum system, the insulation system, the vacuum reduction reaction system, the solid materials continuous feeding system, the magnesium vapor condensing system, the magnesium being collected system and the water cooling system. The new vacuum metallurgical furnace has some features:①Large capacity crucible to contain 5kg mixture materials, raising the production of single metallurgical equipment.②Solid materials can be feed consecutively, improving the thermal efficiency and production efficiency of furnace.③Separate device to condensing magnesium vapor and collect magnesium. The condensing condition of magnesium vapor can be controlled easily. High purity solid magnesium lump can be outputted but the magnesium powder, which can save the follow-up process of magnesium distillation and simplify the process of producing magnesium. The new condensing device can effectively control the production of the magnesium powder, which can reduce greatly the probability of spontaneous combustion of magnesium powder and improve the security of operating environment.After the new vacuum metallurgical furnace is made, it is renovated and debugged:①Heating system: The original transformer, cables, and heating device are all replaced, which increased the heating power of furnace.②Vacuum system: Saving two valves on the condensing device, replacing thread seal by weld seal, adding a vacuum pump of 15L/s,which raised the vacuum of furnace.③Insulation system: Two graphite insulating boards are added on the top of crucible, the graphite base is replaced by insulation bricks,and PCF is used as insulation,which reducing the heat loss of furnace.④Water cooling system: Falling the location of water intake of the main furnace shell and increasing the location of water outlet which improved the effect of water cooling.After the debugging and the renovation of furnace is completed, the new vacuum metallurgical furnace meet the design requirements:①The vacuum of furnace is about 30 Pa under the normal temperature.②Furnace temperature can reach 1400°C in two hours which fits in with carbon reduction of magnesium reaction. Some experiments have been conducted of vacuum carbonthermal reduction of magnesia with the new vacuum metallurgical furnace and get magnesium. |
PDF Full Text Request