工业级磷酸一铵(IMAP)生产时会产生大量的废磷淤渣,磷淤渣采用硫酸酸解后经脱氟、氨中和、冷却结晶、除杂可用来生产硫基磷铵。考察了结晶后的溶液在除杂过程中pH对制备硫基磷铵的影响。结果表明,当溶液pH为2.8时,滤液中MgO、Fe₂O₃和Al₂O₃质量分数分别为0.44%、0.06%和0.41%。硫基磷铵产品经ICP分析,Fe、Al和Mg元素质量分数分别为0.046%、0.074%和0.94%。XRD和红外以及热重分析表明,硫基磷铵是NH₄H₂PO₄和(NH₄)₂SO₄组成的复合物。

The production of industrial monoammonium phosphate (IMAP) will simultaneously generate a large amount of waste phosphorus sludge.Phosphorus sludge can be used to produce ammonium phosphate sulfate through sulfuric acid leaching,defluorination,ammonia neutralization,cooling crystallization,and impurity removal.The effect of pH value of crystallized solution for impurity removal on the preparation of ammonium phosphate sulfate is evaluated.Results show that the contents of MgO,Fe₂O₃ and Al₂O₃ in the filtrate are 0.44%,0.06% and 0.41%,respectively when the pH of the solution is adjusted to 2.8.It is found by ICP analysis that the mass fractions of Fe,Al and Mg in ammonium phosphate sulfate product are 0.046%,0.074% and 0.94%,respectively.It is verified through XRD,IR and thermogravimetric analysis that ammonium phosphate sulfate product may be a compound composed of NH₄H₂PO₄ and (NH₄)₂SO₄.