Thermal treatment of sulfide ores such as molybdenite to produce molybdenum trioxide, by roasting enriched ore concentrate in first reactor, separating the solids in separator, and converting the solid to metallic oxide in second reactor

摘要

The method for the thermal treatment of sulfide ores such as molybdenite to produce molybdenum trioxide, comprises supplying an enriched concentrate of the ore to a first reactor (1), in which the ore is roasted in a fluidized bed under sub-stoichiometric conditions, discharging the roasted solids from the reactor and separating in a separator (6) by fluidization gas, and supplying a part of the separated solids directly to a second reactor (9), in which the solids are again roasted and converted to metallic oxide. The roasting is carried out in the first and/or second reactor at 500-680[deg] C. The method for the thermal treatment of sulfide ores such as molybdenite to produce molybdenum trioxide, comprises supplying an enriched concentrate of the ore to a first reactor (1), in which the ore is roasted in a fluidized bed under sub-stoichiometric conditions, discharging the roasted solids from the reactor and separating in a separator (6) by fluidization gas, and supplying a part of the separated solids directly to a second reactor (9), in which the solids are again roasted and converted to metallic oxide. The roasting is carried out in the first and/or second reactor at 500-680[deg] C. The concentrate water, mud or pulp supplied to the first reactor is added to the processing step. Water is injected into the second reactor. The excess heat in the second reactor is taken out via indirect cooling. An oxygen-containing gas, e.g. air, air with enriched oxygen and/or technical oxygen is used as fluidization gas. A part of the roasted solids obtained in the separator is led back to the first reactor. A pressure and/or atmosphere barrier is intended between the first reactor and the second reactor. A gas flow is removed from the second reactor, where the solids are separated from the gas flow and are led back to the second reactor. The gas flows removed from the first and/or second reactor are led by a dedusting mechanism to separate fine solids, and then led back to the first reactor. The remaining sulfur contained in the roasting-gas from the first reactor is completely converted to sulfur dioxide by air supply. The gas mixture removed from the separators is subjected to a gas wash and is used for the production of sulfuric acid. An independent claim is included for a plant for the thermal treatment of sulfide ores e.g. molybdenite.