New Materials: Large Steelmaking Slag Blocks Using a New Carbonation Process
By T. Takahashi
Concrete Journal, Vol.38, No.2, Feb. 2000
- Synopsis
- One meter cubic porous slag blocks were produced by carbonation of steelmaking slag with the optimum amount of water, and forcibly supplying CO2 deep into the inner part of the block. While the carbonation reaction has been known for years, it has been difficult to achieve a uniform reaction throughout the block, restricting the size of the manufactured block. Using these new conditions, the carbonation reaction occurred homogeneously throughout the blocks. The compressive strength and bulk density of each block were 19N/mm2 and 2.4g/cm3, respectively. When left exposed to various weather conditions in sea water and in the atmosphere for two years, the blocks showed no cracks or destruction. The development of the blocks has great potential to solve the utilization of slag, for example by providing carbonated large blocks for use in artificial reefs and marine plant cultivating beds, and could also prove helpful in inhibiting the greenhouse effect caused by CO2. This Papaper overviews the carbonation reaction and the new process for producing large slag blocks, and discusses their utilization by considering research conducted in past and recent years.
- Keywords:
- carbonation, steelmaking slag, CO2, CaO, CaCO3
