Abstract: The effects of temperature on the dissolution rate of limestone and lime were studied in this paper，and their dissolution rates in pre-slag containing high FeO were also compared at 1 300，1 400 and 1 500 ℃，using a length of 10 mm limestone cube and lime cube as the test sample. The results showed that the dissolution rate of limestone was obviously faster than that of lime under the experimental conditions. The dissolution rate increased with the temperature，it would double when the temperature increased from 1 300 ℃ to 1 400 ℃. There was a stagnation period lasting about 10 to 30 seconds during the dissolution process of limestone and lime at different temperatures，and which the dissolution rate of limestone was lower than lime due to its heat absorption. After the stagnation period，the dissolution rate of limestone was greater than that of lime.

Key words: limestone, lime, dissolution velocity, pre-slag