STEELMAKING SLAG FOR USE AS FERTILIZER STARTING MATERIAL, METHOD FOR PRODUCING STEELMAKING SLAG FOR USE AS FERTILIZER STARTING MATERIAL, METHOD FOR PRODUCING FERTILIZER, AND FERTILIZATION METHOD

摘要

[Problem] To easily and inexpensively supply multiple types of elements as plant fertilizer while avoiding runoff caused by flowing water, even in acidic soils in regions which receive a lot of rainfall and regions where rivers often flood. [Solution] This steelmaking slag for use as a fertilizer starting material contains, in mass%, P2O5 in the amount or 2-8%, inclusive, MnO in the amount of 3-10%, inclusive, boron in the amount of at least 0.005% and less than 0.05%, total iron in the amount of at least 7% and less than 15%, CaO in the amount of 38-48%, inclusive, SiO2 in the amount of 22-30%, inclusive, sulfur in the amount of 0.1-0.6%, inclusive, MgO in the amount of 1-8%, inclusive, and Al2O3 in the amount of 0.5-3%, inclusive. The proportion of soluble P2O5 in the P2O5 is at least 50%, the proportion of soluble MnO in the MnO is at least 80%, the slag basicity is greater than 1.5 and no greater than 2.2, and the bulk specific gravity is 1.9-2.8, inclusive.Se proporciona escoria de fabricación de acero para materia prima de fertilizante, que contiene, en % en masa, P2O5: mayor o igual al 2% y menor o igual al 8%, MnO: mayor o igual al 3% y menor o igual al 10%, boro: mayor o igual al 0,005% y menor al 0,05%, hierro total: mayor o igual al 15% y menos o igual al 30%, CaO: mayor o igual al 29% y menos del 38%, SiO2: mayor o igual al 16% y menos del 22%, azufre: mayor o igual al 0,1% y menor o igual al 0,6%, MgO: mayor o igual al 4% y menor o igual al 8%, y Al2O3: mayor o igual al 0.5% y menor o igual al 3%. Una relación de P soluble2O5 en la que P2O5 es mayor o igual al 50%, una proporción de MnO soluble en ácido cítrico en el MnO es mayor o igual al 80%, una basicidad de escoria expresada por (un contenido de CaO / a SiO2 ) es más de 1,5 y menor o igual a 2,2, y una gravedad específica mayor es mayor o igual a 2,3 y menor o igual a 3,2.