FIELD: chemistry.
SUBSTANCE: invention relates to production of soluble phosphates of sodium, potassium and ammonium. First version of method involves reaction of calcium phosphate-containing ore with nitric acid solution, separation of calcium dihydrophosphate and/or calcium hydrophosphate, their mixing in a separate vessel with a solution of an alkaline reagent in form of sodium hydroxide, carbonate or hydroxocarbonate, potassium or ammonium to form calcium phosphate precipitate, which is separated by filtration to produce the target product. Second version of the method involves interaction of ore containing calcium phosphate with a solution of nitric acid and separation of insoluble admixtures by filtration. Filtrate is mixed with 1–50 wt% nitric acid solution containing trivalent iron ions in form of ferric nitrate with concentration of 1–800 g/l, and adding alkaline reagent solution until solution pH is 0.5–2.5 and obtaining trivalent iron phosphate precipitate, which is separated by filtration and mixed in a separate container with a solution of an alkaline reagent to form a precipitate of trivalent iron hydroxide, which is separated by filtration to obtain the desired product.
EFFECT: invention enables to obtain from insoluble calcium phosphate a target basic product – soluble acidic and medium phosphates of sodium, potassium or ammonium.
9 cl, 2 ex
