Silicic fertilizer and production method thereof

摘要

This invention provides a silicic fertilizer using a slag produced in a preliminary treatment of a molten pig iron and imparted with a high soluble silica content, and a production method of such a silicic fertilizer. CaO is added and oxygen is blown into a molten pig iron while adjusting a basicity (CaO/SiO2) to 3 or below, and the molten pig iron is subjected to desiliconization and dephosphorization. The resulting slag is collected to produce the silicic fertilizer. This silicic fertilizer has a basicity (CaO/SiO2) of not greater than 3 and contains 15 to 35 mass % of soluble silica.