Table 1 shows that the most of AC pores are open pores. Besides, the opening porosity ratio of recycled AC and the C-x is obviously higher than fresh AC and increases with the cycle times, because AC is further activated by the sulfuric acid during the generation process.[17-18] In addition, the closed porosity ratio of fresh AC is between 4.83%-6.63%. The closed porosity ratio of recycled AC and the C-x is obviously lower than fresh AC, because the closed pore is opened due to the activation of sulfuric acid. Simultaneously, the closed porosity ratio of Re-F is up to 10.11%, because it is made from the porous AC powder and the pore is sealed to become closed pore by coal tar during reconsolidation. Comparing the mechanical strength indexes of F-1 and C-x, after recycled in the flue gas purification facility, AC average compressive strength reduces from 499 N to 340 N, about 70% of original compressive strength, while the abrasion resistance increases from 97.18% to 98.88% because its surface is smoothed during recycling.