Properties and usage of iron and steel slag

Iron and steel slag is produced 33 million ton a year in Japan. Utilizing the great amount of slag is significantly important. The paper presents the properties and usage of the three types of slag:granulated blast furnace slag,air-cooled blast furnace slag and steel slag. The granulated blast furnace slag has especially useful properties such as light weight,high permeability and latent hydraulic property. Because of the useful properties, the granulated blast furnace slag was utilized in port and harbour construction of three types,which is introduced as an example. The steel slag is comparatively difficult to use because of its properties,and is disposed in special site. But steel slag has useful properties such as heavy weight. The authors are making some efforts to utilize steel slag in port and harbour construction of three types,which is also introduced. In order to focus on discussion about the granulated blast furnace slag and steel slag,only a brief description is made for the air-cooled blast furnace slag in this paper.