Preparation method of spherical micro-nano calcium carbonate

The invention discloses a preparation method of spherical micro-nano calcium carbonate. The preparation method comprises the following steps of (1) preparing an ammonium carbonate-additive solution or ammonium bicarbonate-additive solution, wherein the concentration of NH4 is 0.5 to 4mol/L, the concentration of an additive is 1 to 2mg/L, and the additive is selected from potassium ferricyanide, L-glutamic acid, polyvinylpyrrolidone, beta-cyclodextrin, sodium polyphosphate, pentaerythritol, sodium pyrophosphate, monosodium phosphate, sodium phosphate, sodium hexametaphosphate, sodium trimetaphosphate or sodium tetraborate; (2) preparing a calcium salt solution, wherein the concentration of Ca is 1 to 3mol/L; (3) dripping the solution in step (1) into the calcium salt solution at the rate of 2000 to 4000ul/min, reacting for 1 to 4h at the temperature of 20 to 50 DEG C, and stirring at the rate of 200 to 400r/min during dripping and reaction; (4) washing, sucking and filtering, and drying; (5) fetching ou