Utilization of Coal Gasification Slag Collected from IGCC as Fine Aggregate for Concrete

The Integrated coal Gasification Combined Cycle (IGCC) has received a lot of attention in recent years from the viewpoint of reducing CO2 emissions. IGCC is basically different from conventional pulverized coal-fired thermal power generation systems; electricity is generated by a combined cycle using gas turbines and steam turbines. Thus, it is said that IGCC is much more efficient than a conventional coal-fired power plant. In IGCC, the by-product is collected not as coal ash but as coal gasification slag. Coal gasification slag has a tremendous amount of potential for effective use in the field of concrete production because no hazardous material leaches from it and it is simple to handle compared with coal ash. This paper describes how the aggregate test and concrete test were conducted on coal gasification slag in order to examine whether coal ash slag can be used as a fine aggregate for concrete. The results of these tests showed that concrete made from slag has almost the same compressive strength as concrete in which natural sand is used. In addition, the drying shrinkage rate and freeze-thaw resistance, which are values related to the durability of concrete, of such slag concrete did not show any difference from those of concrete made with natural sand. From these experimental results, it can be concluded that coal gasification slag has a possibility for use in structural concrete.