Research On Roasting Molybdenum Oxide With Auto-thermal Rotary Kiln

There are two problems when using rotary kiln to roast molybdenum concentrate. First, the reaction of roasting molybdenum concentrate is a high-exothermic reaction, but in industry production, we fail to use the large amount reaction heat. Second, MoO3is more widely used than MoO2in industrial application, but under the existing roasting technology, in roasting product, the content of MoO3is low, the content of MoO2is high.To solve these problems, we develop the technology of roasting MoO3with auto-thermal rotary kiln. Before the technical renovation of1#rotary kiln in Luoyang molybdenum industry, we take a thermal test on1#rotary kiln, in order to know the heat loss of roasting which will provide the basis for further technical renovation. Basing on this, we put forward the technology solutions of roasting MoO3with auto-thermal rotary kiln. Then we do heat balance calculation after thermal test of the modified rotary kiln. On the basis of thermo-gravimetric experiments, the roasting mechanism of MoO3was studied, which provides a theoretical basis to using Comsol software to carry out simulation of rotary kiln before and after the technical renovation.In this Paper, we draw the following conclusions:First, the test results show that among the roasting products, the ratio of molybdenum trioxide is as high as98%, which illustrates it possible to roast molybdenum oxide with auto-thermal rotary kiln.Second, basing on the thermal test and heat balance calculation of modified1#rotary kiln, we can draw the conclusion that it realize the zero consumption of fuel and energy saving effect is remarkable.Third, we calculate the activation energy, mechanism of function and pre-exponential factor of the reaction. On basis of these, we calculate two-phase reaction mechanism equation of roasting reaction. Fourth, through simulation, the paper finds that the temperature of reaction part of auto-thermal rotary kiln is lower than traditional rotary kiln, realizing the control of reaction temperature, which benefits to improve the recovery rate of molybdenum.