Rotary corrosion tests were done using refractories including chromium trioxide of 12 to 81％, which have been frequently used in wastes melting furnaces,by varying slag basicity. Leachate tests were done using water-cooled slag, refractories and the slag adhered to refractories obtained by the corrosion tests. There was a tendency that Cr2O3 content in both water-cooled slag and the adhered one was increased with increasing of Cr2O3 content of refractories, and so maximum contents were 10％, 22％, respectively. Leachate test by Environmental Agency Notification No.46 was done and it’s found that Cr6＋ leachate concentration was increased with increasing of Cr2O3 contents and slag basicity of both water-cooled slag and the adhered slag. Si and Ca leachate concentration indicated the same tendency with Cr6＋ one. Water-cooled slag did not exceed the environmental leachate standard in all cases but the adhered slag exceeded the standard in case of Cr2O3 contents of more than 30％. Very high Cr6＋ concentration was measured by leachate test of the surface area of tested refractories. In case of the refractories including Cr2O3 of 62％ at the slag basicity of 1.2, the ratio of amounts of total chromium shifted to cooling water, water-cooled slag and the adhered slag from the refractories was 0.06％, 81％ and 19％, respectively.

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