BENAVIOR OF ALKALI METAL CYANIDES IN THE BLAST FURNACE - VAPORIZATION OF NaCN(l) AND KCN(l).

Vaporization of alkali metal cyanides is related to the emission of cyanides from the blast furnace. Cyanide vaporization is also an important step in the alkali cycle in the blast furnace. The rates of vaporization of liquid NaCN and KCN were studied in the temperature range 923-1123K. Experiments were conducted in argon, helium, nitrogen, krypton and helium-argon mixtures. The rates of vaporization of both NaCN and KCN were proportional to the diffusivities of both the monomeric and the dimeric form of the respective cyanide vapors in the inert gases (or gas mixtures). The values of the apparent activation energies for the vaporization of KCN(l) and NaCN(l) were 70320 KJ/kg mole (16. 8 kcal/mole) and 81850 KH/kg mole (19. 6 kcal/mole) respectively. The relevance of the kinetic data to the blast furnace operation is discussed.