The present invention relates, in general, to the purification of boron trichloride (BCl3). More particularly, the invention relates to a process for minimizing silicon tetrachloride (SiCl4) formation in BCl3 production and/or the removal of SiCl4 in BCl3 product stream by preventing/minimizing the silicon source in the reaction chambers. In addition, a hydride material may be used to convert any SiCl4 present to SiH4 which is easier to remove. Lastly freeze separation would replace fractional distillation to remove SiCl4 from BCl3 that has been partially purified to remove light boilers.