Microwave Pyrolysis and Purification Technology
Figure 1. Main concept of pyrometallurgy [1]
Introduction of pyrometallurgy:
Pyrometallurgy is an important method in the recycling and purifying field which purifies the material by controlling the temperature and the partial pressure. In the real case, mixed metal can be separately collected by fine control of temperature and partial pressure, shown as figure 1. In other words, we can obtain the high purity tin metal by controlling the parameters under B regime. Most importantly, this concept is widely adopted by industry and realized as a large-scale and continuous method to purify the material.
Rereasech interest:
However, traditional pyrometallurgy has a critical defect,which is higher energy consumption. To eliminate the problem, we induce the microwave technology. We found that using microwave can rapidly raise the material temperature and further decrease the reaction time, as shown as figure 2. We believe the microwave technology is a path to further improve the high-energy-consumption issue in pyrometallurgy.
Figure 2.Comparison of microwave and conventional carbothermic reductions[2]
Research methodology:
Microwave has been researched for many years, however, most of the research are made in nano- or micron-scale, which is a concern for scale-up. Here, we focus on the working mechanism of microwave heating and design the novelty microwave furnace including cooling system, vacuum system and efficient heating system. Our experiments focuses on recycling materials which have high dielectric coefficient and which are high-microwave-absorption, in order to eliminate the high-energy-consumption issue and obtain the high purity metal material.
Figure 3. references of material’s dielectric loss factor and power absorption [3]
[1]Jiang, Wen-Long, et al. "Application of vacuum distillation in refining crude indium." Rare Metals 32.6 (2013): 627-631.
[2] Haque, K. E. (1999). Microwave energy for mineral treatment processes—a brief review. International journal of mineral processing, 57(1), 1-24.
[3] Prado-Gonjal J. Microwave-assisted synthesis and characterization of inorganic materials. PhD Thesis. Chapter 6. Universidad Complutense de Madrid. 2014.