Purified monoammonium phosphate process

摘要

A method of producing purified monoammonium phosphate from wet process phosphoric acid and ammonia is provided. The ammoniation takes place in two stages, the acid being ammoniated in the first stage to a pH between about 1.5 and 2.5. This mixture is allowed to age after which the mixture is ammoniated to a pH between about 4 and 5. An impurity-containing precipitate is formed in the first and second stages of ammoniation that is easily filterable from the monoammonium phosphate solution derived from the second ammoniation stage.