PROCESS FOR RECOVERY OF TECHNICAL GRADE MOLYBDENUM FROM DILUTED LEACHING ACID SOLUTIONS (PLS), WITH HIGHLY CONCENTRATED ARSENIC, FROM METALLURGICAL RESIDUES

摘要

A method for recovering technical-grade molybdenum from diluted acid leaching solutions (PLS) that have a high arsenic concentration is disclosed. The method includes: (a) bringing a pre-filtered acid leaching solution (PLS), originating from the leaching of smelter dust, into contact with an anionic ion-exchange resin; (b) washing the loaded resin with water; (c) extracting molybdenum from the ion-exchange resin with an alkaline ammonium regenerant solution to form ammonium molybdenum in solution; (d) washing the unloaded resin with water; (e) adding iron and/or magnesium salts to the recovered ammoniacal solution to obtain a precipitate which is transferred to the arsenic abatement step and a solution containing ammonium molybdate in solution; (f) adding sulphuric acid to the arsenic-free ammoniacal solution in order to precipitate the moylbdenum in the form of ammonium molybdate; (g) separating the precipitate by filtering the molybdate and re-circulating the solution obtained with the initial PLS solution; (h) calcining the separated precipitate to obtain ammonia and molybdenum trioxide; and (i) recovering the released ammonia for its subsequent use in the method as a recirculated regenerant solution.