Preparation method of strontium-rich liquid fertilizer

The invention discloses a preparation method of a strontium-rich liquid chemical fertilizer. The method comprises the following steps: taking bentonite pickling wastewater containing K, Na, Ca, Mg, Fe and Sr as a raw material, firstly adding caustic soda flakes to neutralize the wastewater until the pH value of the wastewater reaches 6.0-7.0; introducing a supernatant into areverse osmosis water treatment device, and concentrating until the concentration of K is 10.0-20.0 g/L, CaSO4 is supersaturated, the concentration of Mg is 30.0-40.0 g/L, the concentration ofFe is 0.3-1.0 g/L and the concentration of Sr is 3.0-4.0 g/L; finally, adding ammonium nitrate, potassium nitrate and calcium hypophosphite in proportion, so that the molar ratio of N to P toK in the compound fertilizer is 20: (15-5): (15-5), and the concentration of P reaches 10.0-20.0 g/L. The method has the advantages that the process is simple, and the operation is convenient; industrial wastewater is utilized,