Abstract:The surface corrosion of anode carbon blocks in rare earth electrolytic cell caused by anode reaction was investigated. The results show that after a production cycle (1 h), the porosity of different anode carbon block sample ranges between 0.006 9±0.001 4, but with a big difference of specific surface area of sample. This indicates that the reaction amount in anode carbon block is basically same and regional distribution is equal, the difference in direction of reaction is big. Big specific surface area tends to anode effect and anode discharging. Size of additives should be as small as possible and be evenly mixed with carbon block.