Copper concentrate particles were fed from the top of vertical reaction tube of 2.8 cm ID and 65 cm long with an $O_2$-$N_2$ gas mixture. The reaction tube was heated to 1000 K to 1400 K. The copper concentrate particles were very rapidly oxidized and melted down during their descent in the reaction tube. The particle temperature were calculated by combining an unreacted core model, mass transfer between gas and particles, and heat transfer between gas, particles and tube wall. The particle temperature reached its maximum at the height of 20 to 30 cm from the top of the reaction tube, and it attained about 1700 K at higher oxy-gen partial pressure. The most particles were melted at the oxygen partial pressure above 0.2 atm.