China Nonferrous Metallurgy

The molybdenum ore of an enterprise is a typical low-grade and semi-oxidized ore. Its ore composition and structure are complex. It is embedded in the form of molybdenite， molybdenum calcium ore and molybdenum oxide ore. Molybdenite is associated with other minerals. Some molybdenum calcium ore and other minerals are isomorphic to form new minerals. The ore particle size is fine and evenly distributed. The molybdenum content is 0. 45%， which belongs to low-grade refractory molybdenum ore. In this study， the synergistic oxidation leaching of sodium percarbonate and sodium hydroxide was used to recover molybdenum， and the effects of different factors on the leaching rate of molybdenum were investigated. The results show that the leaching rate of molybdenum is 88. 32% under the optimum conditions of ore particle size of 80%-45 μm， liquid-solid ratio of 3 mL/g， sodium percarbonate dosage of 20 kg/t， sodium hydroxide dosage of 15 kg/t， leaching temperature of 85℃， leaching time of 4 h and stirring rate of 500 r/min. The results of kinetic study show that the leaching process of molybdenum ore is controlled by chemical reaction and diffusion， and the activation energy of reaction is 19. 98 kJ/mol. Before and after leaching， the composition of gangue minerals is basically unchanged， and a small amount of molybdenum calcium ore remains in the slag. Molybdenite has been completely leached. In the future， the structure of molybdenum calcium ore can be destroyed by strengthening ore pretreatment or the reaction conditions can be optimized to obtain higher leaching rate. The oxidant used in this process is mild， stable and environmentally friendly， and the leaching impurities are less. The whole leaching process has no high temperature， no flue gas and short process， which realizes the efficient recovery of metal molybdenum resources and provides a reference for the utilization of this kind of low-grade complex molybdenum ore resources.