New frontiers in thermal plasma processing

Thermal plasma technology applications are presently focused on two principal thrust areas: materials processing and the treatment of waste materials. Materials processing covers activities such as surface modification and plasma spray coating, powder spheroidization, and plasma chemical synthesis of ultrafine high purity materials. These have evolved as a mature science with considerable economic activity. Especially in the area of plasma spraying of protective coatings such as wear resistant and thermal barrier coatings. In the waste treatment area, the aim has been either the reclamation of waste material in order to recover higher added value products or the destruction of toxic wastes. A review is presented of the progress in each of these two frontiers. Research needs required to achieve significant advances in plasma source development, and fundamental understanding of the underlying fluid dynamics, heat and mass transfer phenomena, are discussed.