Study On Recovery Of Valuable Metals From Waste Petroleum Refining Hydrogenation Catalyst

With the rapid development of the petrochemical industry,the production of petroleum smelting hydrogenation catalysts is huge,and how to effectively dispose of spent catalysts has become a hot spot of concern.The waste catalyst contains a large amount of non-ferrous metals,and the composition is relatively simple.The recycling of the waste catalyst can realize the recycling of resources and has certain economic benefits.Therefore,exploring the efficient and clean recovery process of spent hydrogenation catalysts has a certain role in promoting the good and orderly development of the petrochemical industry and the realization of resource recycling.In this paper,the sodium roasting-water leaching method,chemical precipitation method and extraction method are used to realize the separation and recovery of Mo,Ni,and Al in the spent hydrogenation catalyst.The sodiumization roasting-water leaching process and roasting mechanism of the spent hydrogenation catalyst were investigated.The N235 solvent extraction method and the calcium salt and barium salt precipitation method were used to recover molybdenum and aluminum from the leaching solution.The effect of the leaching-extraction method on the leaching Recycling of nickel in slag.The main research results are as follows:(1)Research on the optimization of the sodiumization roasting-water leaching process and the roasting mechanism of the spent hydrogenation catalyst.The suitable pretreatment temperature is 400?500?.As the pretreatment temperature increases,molybdenum and aluminum combine to form Al₂(Mo O₄)₃,which can participate in the sodiumization reaction;the response surface method is used to calcinate the sodiumization-The water leaching process is optimized.The leaching rate of molybdenum exceeds 98%,and the leaching rate of aluminum exceeds 94%;When the amount of sodium carbonate added is less than 1.1 times the mass of the catalyst,the molybdenum and aluminum that have not participated in the sodiumization reaction will combine to form Al₂(Mo O₄)₃;According to the analysis of TG-DSC results,the temperature of the sodiumization reaction of molybdenum and aluminum is between 700 and 1000?.(2)Study on the process of separating and recovering molybdenum from the leachate by calcium salt and barium salt precipitation.Adjust the p H of the leaching solution to 8.5 to obtain an amorphous aluminum hydroxide precipitate,which can be calcined to obtain?-Al₂O₃ with a mass fraction greater than 98%;adjust the p H of the solution to 9.5,add 1.8 times the theoretical amount of saturated magnesium chloride solution at 70?,and react15 minutes,more than 95%of the impurity phosphorus can be removed;add1.5 times the theoretical amount of calcium chloride and barium chloride to the de-impurity leaching solution,and react at 70?for 30 minutes to obtain uniform particle size distribution.Nano-level calcium molybdate and barium molybdate;the mass fraction of calcium molybdate reaches 97%,and the mass fraction of barium molybdate reaches 98%.(3)Research on the technology of extracting and recovering molybdenum from the leaching liquid by using N235.Adjust the p H of the leaching solution to 1.5?2,and use N235 extractant to extract the leaching solution in three stages;ammonia water is used as the stripping agent,the molybdenum stripping rate reaches 98.62%;the ammonium molybdate solution obtained by stripping is added with Mg(NO₃)₂ to generate solubility Smaller magnesium phosphate and magnesium silicate can remove impurities;the ammonium molybdate solution removes impurities again,evaporates and crystallizes to obtain ammonium paramolybdate.The suitable conditions for preparing molybdenum trioxide from ammonium paramolybdate are:400?for 1 h.(4)Research on the separation and recovery of nickel from the leaching residue by the leaching-extraction method.Dilute sulfuric acid is the leaching agent,the leaching rate of nickel and aluminum is greater than 98%;the activation energy of the acid leaching reaction of nickel is 16.10 k J/mol,which conforms to the shrinkage unreacted nuclear model of internal diffusion control;the organic relative nickel extraction rate of P204 and sulfonated kerosene It can reach 99.24%,and the stripping rate of nickel with dilute sulfuric acid is over 99.23%;the nickel sulfate solution obtained by stripping is evaporated and crystallized to obtain nickel sulfate hexahydrate,which is calcined at 850?for 1 h to obtain nickel oxide.This study shows that the sodiumization roasting-leaching method can achieve high-efficiency leaching of valuable metals in the spent catalyst,and the combination of chemical precipitation and extraction methods can obtain products such as calcium molybdate,barium molybdate,molybdenum oxide and nickel oxide.This article provides technical support and theoretical basis for the recovery and utilization of spent hydrogenation catalysts.