Synthesis and Characterization of Nano-sized Boron Powder Prepared by Plasma Torch

Hydrogen thermal plasma jet was employed to prepare nano-sized boron powderwith hydrogen reduction of BCl;. The maximum yield of nano-sized boron powders was about50% with the operational conditions of H;/BCl;of 4.5:1, total feed of 4.9 m;/h, and plasmapower of 25 kW. The samples were analyzed by X-ray diffraction （XRD）, field emission scanningelectron microscopy （FE-SEM）, and inductively coupled plasma - mass spectrometry （ICP-MS）,inductively coupled plasma - atomic emission spectrometry （ICP-AES）, inductive combustioninfrared absorption （ICIA） and infrared thermal conductivity of oxygen and nitrogen analyzer（ITCA）. The results show that the boron powders have different crystal structures with higherdispersion and purity. The average diameter is about 50 nm, and the purity is 90.29% or so. Thisnew technology can use simple process to produce high quality boron powders, and is feasible forindustrial production.