ISIJ International
Online ISSN : 1347-5460
Print ISSN : 0915-1559
ISSN-L : 0915-1559
Regular Article
Solidification Conditions to Reduce Porosity of Air-cooled Blast Furnace Slag for Coarse Aggregate
Hiroyuki ToboYoko MiyamotoKeiji WatanabeMichihiro KuwayamaTatsuya OzawaToshihiro Tanaka
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2014 Volume 54 Issue 3 Pages 704-713


The solidification conditions to reduce the porosity of air-cooled blast furnace slag were investigated. From cross-sectinal observation of solidified slag, growth of gas bubble generated in molten slag was estimated to be cause of high porosity. With low thermal conductivity slag, increasing the cooling rate by thin slag casting was effective for reducing the porosity of air-cooled blast furnace slag.
As a method of reducing the porosity of air-cooled blast furnace slag, a process was developed in which the slag is solidified to a plate thickness of 20–30 mm in about 2 minutes by pouring the molten slag in a cast steel mold. When porosity reduced, the abrasion resistance of the slag improved. The possibility of using low porosity slag as aggregate for drainage pavement was confirmed in an experiment with test pavement.

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© 2014 by The Iron and Steel Institute of Japan
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