Ultrasonic Electro-oxidation Of Molybdenite Decomposition Of The New Technology Research

According to the shortcomings of the roasting process (pollution of flue gas containing sulphur, poor metal comprehensive recovery) and clean process-hydrometallurgy of molybdenite, studying new decomposition method of molybdenite is necesary. Ultrasound electro-oxidation process was sudyied which can combine electric field and ultrasound on the basis of electro-oxidation process in order to solve the shortcomings of roasting process and process-hydrometallurgy.After studying the mechanism and experiments of electro-oxidation process,the reason of low Mo leaching rate and current efficiency was inert membranes during electro-oxidation process, which block the reaction.To promote electrochemistry reactions in electro-oxidation process for molybdenite, it's necessary that mass transfer among leaching agent, mineral and product should be strengthened by using of the coupling between electric field and ultrasound, so that inert membranes could be destroyed by the role of stripping, rapid dissolution or chemical oxidation.Ultrasound electro-oxidation process was studied using of carbon electrodes in self made cell. The optimal reaction conditions were obtained.The optimal conditions are as follows: the emission of ultrasonic of three minutes per 15 minutes, electrolyte concentration C_NaCl of 10%, pulp initial pH of 10, cell voltage of 3.5 v, temperature of 25℃, liquid to solid ratio L/S of 50. Current efficiency and Mo leaching rate can reach 91.9% and 191.8% under the optimal conditions.There were many shortcomings of carbon electrode according to the small size experiments. In order to further perfect the ultrasonic electro-oxidation process, its cell system was designed and optimized. Verification tests' results show that the new electrolysis device can achieve the coupling between electric field and ultrasound, and strengthen molybdenite oxidative decomposition and leaching. The voltage was decresed from 3.5V to3.0V. Mo leaching rate was increased from 91.9% to 94.2% and current efficiency increased to 196.5%.The influence of ultrasound to electrodes was studied. Reasonable explanation of high current efficiency in the electrolysis process in the novel process was put forward.The first reason is ultrasonic cavitation disperse pulp increasing activation center, which enhance the efficiency of hypochlorite. The second reason is inert membranes destroyed by the role of stripping, rapid dissolution and chemical oxidation entering solution. The third reason is that oxygen which dissolveing in solution decompose molybdenite. The fourth is the possibility of direct collision anodic oxidation and direct oxidation by ultrasound. The last one is that hydroxy oxidates and decomposes molybdenite. The mechanistic of decomposition molybdenite was brought forward at last.