PROCESS FOR THE EXTRACTION OF MOLYBDENUM VALUES FROM MOLYBDENUM ORES OR CONCENTRATES CONTAINING MOLYBDENUM TRIOXIDE

摘要

1493158 Extracting molybdenum from ores AMAX Inc 16 Oct 1975 [21 Oct 1974] 42472/75 Heading ClA Molybdenum values are extracted from ores or concentrates containing molybdenum trioxide by (1) mixing ground particulate impure feed material with sulphuric acid, such that the ratio of acid to metal impurities is at least 1:1, (2) agglomerating the mixture, (3) baking the pellets at 150-250‹ C., (4) roasting at 300‹ C. or more to form watersoluble sulphates of the impurities, (5) grinding to less than 100 mesh, (6) leaching with water at 50‹ C. or higher to extract the sulphates, (7) separating the residue from the leach solution and contacting the residue with aqueous ammoniacal leach solution to form a solution containing ammonium molybdate compounds and an insoluble residue, (8) recovering Mo values from the solution. The feed material is preferably ground to less than 100 mesh. The leach solution from step (7) may be treated with lime to precipitate a calcium molybdate compound which is recycled to the roaster. Ammonium dimomolybdate, recovered in step (8) by crystallization may be calcined to form an MoO 3 product.