Molybdenum Waste Water, Waste Oil Comprehensive Treatment Of The Catalyst And Recycling Of Valuable Resources Utilization

This study mainly covers two aspects: firstly, the comprehensive processing of the industrial effluent during the production of ammonium molybdate and the recovery of the negotiable resources; secondly, the recovery of V and Mo in the spent catalysts.As for the processing of the acid wastewater produced in the ammonium molybdate production, the mixed technology of chemical precipitation and ion exchange has been adopted in this research. The rare metal Mo from the deposit slags produced in precipitation can be recovered by way of the disposal through ammonia water. After the wastewater has been processed jointly by these twomethods, most Cu2+, Fe3+, Pb2+ , Zn and Mo in the solution can be removed quite well, K+, Ca2+ and Mg2+ can be partially removed while Na+ can not. The processed waste water can be crystallized directly to produce NH4NO3 which basically accords with the national quality standard of the industrial NH4NO3.As to the disposal of the spent catalysts, this research unfolds in the following technological process: calcinations - leaching - decontamination - vanadium precipitation - molybdenum precipitation. During the calcinations-leaching stage, three different kinds of leaching methods have been adopted in this research for comparison, i.e., blank calcinations-ammonia water leaching, blank calcinations-sodium carbonate leaching and calcinations with addition of sodium carbonate-water leaching. At first, weak-base ammonium salt is used to precipitate V from the leaching solution, then acid neutralization is adopted to precipitate Mo from the mother liquid. The experimental results show that the three methods have their respective merits and demerits, among which the third one is most efficient in leaching out the negotiable metal V and Mo in the spent catalysts. The leaching rate of V2O5 can at best come to 98.77% and that of Mo can reach 99.04%. In the course of vanadium precipitation, V in the leaching solution can be satisfactorily separated by precipitation, and acid neutralization is adopted directly to the mother liquid for vanadium precipitation, due to the relatively low concentration of Mo in the leaching solution, which results in the rather low precipitation rate of Mo (82.68%).To sum up, both of the two above-mentioned technologies can meet the requirements of economic development and environmental protection, andaccordingly, possess prevailing industrial practical values.