The present invention discloses a multi-element comprehensive utilization process for
phosphorus-
potassium associated ore. The process comprises: firstly, a
fluorine-containing compound is used as an additional aid, and a leaching reaction of the
phosphorus-
potassium associated ore at a low temperature under an acidic condition is implemented, so as to obtain a silica residue and a
leachate. The steps of
calcium removal,
hydrochloric acid distillation and
neutralization are then performed successively to the resulting
leachate, so as to obtain a
calcium sulfate residue, a heavy iron residue, a heavy aluminum residue, a heavy
magnesium residue, and a filtrate. The resulting filtrate is then supplemented with
phosphorus, evaporated, and concentrated, so as to obtain a
high concentration of NPK compound
fertilizer. According to the process provided by the present invention, the
fluorine-containing compound is used as the additional aid and
hydrochloric acid is used as a leaching agent to process the phosphorus-
potassium associated ore.
Potassium feldspar is decomposed by means of a reaction of villiaumite and an acid to generate
hydrofluoric acid in situ, effectively implementing a process of complete
decomposition, complete separation and complete utilization. The process has advantages of low
energy consumption, a high element
leaching rate, and simple subsequent treatment processes, etc. No
discharge problem of three waste exists in the treatment process. In addition, the involved process is simple and the
reaction conditions are mild, so that the process is easy to implement and is suitable for popularization and application.