Most of coal ash produced in the coal thermal power stations in Japan has been disposed for landfilling on the land and in the sea. However, in the near future, it is anticipated that newly built power stations will face the sevier problems of the coal ash disposal because of the deficient spaces for disposal. On the other hand, it is apparent that there will be a shortage of the natural resources for construction, for example, limestones, clays, aggregates and sonds. Therefore, if the coal ash is effectively utilized for the construction material, the problem of the coal ash disposal in the power stations will be solved.
In some countries, the technology of the coal ash utilization has been developed, and in fact, the coal ash produced from the power stations are successfully used for the cement manufacturing and also for the concrete replacing. In this paper, the author illustrated some examples of the successful utilization of the coal ash and pointed out some problems to be solved in Japan. It is necessary to establish and develop the technology for coal ash utilization, which includes the upgrading of coal ash based on the economical advantage of the final products.
