Basic Slag & Pelophos are come under

Basic slag and Pelophos come under Citrate soluble.
Basic slag is a slag low in silica and high in base-forming oxides that are used in the basic process of steelmaking and that is subsequently useful as a fertilizer.
The alkaline Phosphorus fertilizer manufactured from rock phosphate and foundry slag contained 17 - 18% P₂O₅ and Mg and various micro-nutrients and were more effective on grassland than superphosphate.