10 NaN3 + 6 SiO2 + 2 KNO3 → K2SiO3 + 5 Na2SiO3 + 16 N2
This is an oxidation-reduction (redox) reaction:
30 N-1/3 - 10 e- → 30 N0 (oxidation)
2 NV + 10 e- → 2 N0 (reduction)
NaN3 is a reducing agent, KNO3 is an oxidizing agent (synproportionation (comproportionation)).