The production method is that the main raw material of phosphate fertilizer is phosphate rock. There are two main methods to decompose phosphate rock: acid method and thermal method;
1, acid phosphate fertilizer: phosphate fertilizer or compound fertilizer is generally made by decomposing phosphate rock with sulfuric acid, nitric acid, hydrochloric acid or phosphoric acid. Acid phosphate fertilizer is mostly water-soluble phosphate fertilizer, such as calcium superphosphate.
2. Hot phosphate fertilizer: phosphate fertilizer made by adding silica, dolomite and coke. Or decompose phosphate rock at high temperature without adding other components. Hot phosphate fertilizer is mostly citric acid soluble phosphate fertilizer, such as calcium magnesium phosphate fertilizer. Matters needing attention in the use of phosphate fertilizer:
Extended data calcium superphosphate:
Ca(H2PO4)2 is mixed with CaSO4. Soluble in water, it is an acid instant fertilizer, which can be applied to neutral and calcareous soil, and can be used as base fertilizer, topdressing, seed fertilizer and topdressing outside roots. Be careful not to mix with alkaline fertilizer to prevent acid-base neutralization and reduce fertilizer efficiency; Mainly used in phosphorus-deficient soil, the application amount depends on the degree of phosphorus deficiency in the soil, and the foliar spraying concentration is 1-2%.
Calcium magnesium phosphate fertilizer:
It is a multi-element fertilizer with phosphorus as the main component, and also contains calcium, magnesium, silicon and other components. This is an alkaline fertilizer which is insoluble in water. It is suitable for acid soil, with slow fertilizer efficiency and better application as base fertilizer. It can't be mixed with superphosphate and nitrogen fertilizer, but it can be used with acid fertilizer, which has better effect on acid soil lacking silicon, calcium and magnesium.
Monoammonium phosphate and diammonium phosphate:
It is a high-concentration effective nitrogen and phosphorus binary compound fertilizer with phosphorus as the main component, which is easily soluble in water. Monoammonium phosphate is an acidic fertilizer and diammonium phosphate is an alkaline fertilizer. It is suitable for all kinds of crops and soils, mainly used as base fertilizer and seed fertilizer.