Processing of Copper-Containing Molybdenite Concentrates by Roasting with Sodium Salts to Produce Technical Molybdenum Trioxide

The paper discusses methods of processing copper-containing molybdenite concentrates. A process flow diagram based on roasting with sodium chloride (or carbonate) and subsequent water leaching is presented. The chemistry of sulfide interaction with salt additives is described. The effect of the roasting temperature on copper and molybdenum distribution among the process products was studied. It was found that during roasting, 75 to 80% of molybdenum is converted from the sulfide into trioxide form, while copper predominantly forms water-soluble compounds and, thus, enables extraction by water leaching. It was established that the cake obtained as a result of water leaching meets the requirements for raw materials used for ferromolybdenum smelting.