SKIMMING AGENT AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To secure clean molten metal that does not contain any impurities by using a skimming agent that is made of a granular body with a specific particle diameter of expandable volcano eruptions with a silicon oxide content where alkali metal oxide content has been adjusted to a specific range. SOLUTION: A granular body or expandable volcano eruption powder has a particle diameter within a range of 0.1-10 mm of expandable volcano eruptions with 65-80 wt.% silicon oxide content where the alkali metal oxide content has been adjusted to a range of 8.5-10 wt.% by adding an alkali supply substance. Then, solution containing a sufficient amount of water-soluble alkali metal compound for setting the alkali metal oxide content to 8.5-10 wt.% and a required amount of water-soluble silicon compound for setting the silicon oxide content to 65-80 wt.% as needed is added to the granular body and the volcano eruption powder. Then, after the mixture is dried, granulation and classification are made to collect a fraction within a particle diameter range of 0.1-10 mm.