Boron-nitride production by the condensation-combustion method

The thermal reduction of boron halide by alkali-metal vapors in the presence of ammonia is proposed for the production of boron nitride by condensation combustion. Combustion temperatures and equilibrium composition of the products are calculated. Self-propagating regimes of condensation combustion in an oxygen-free system are realized. A unit for producing condensed products with variation of the combustion parameters is designed. It is shown that the combustion products formed contain polycyclic structural fragments of boron nitride with characteristic sizes of $\sim$ 8,8 $\cdot$ 10$^{-10}$ m.