Method for recovering rare earth from catalyst waste residues

Abstract

The invention relates to a method for recovering rare earth from catalyst waste residues. The method, which can be adopted to reach the purpose of waste utilization, comprises the following steps of: carrying out a reaction between catalyst waste residues containing rare earth and acid, dissolving rare earth and some metal ions, followed by filtration separation, separating rare earth from the filtrate by the solvent extraction separation method or the oxalic acid precipitation method, removing aluminium by the form of aluminium salt, mixing the extractant and the filtered solid substance, followed by a reaction among the mixture, the aluminium salt and an alkaline substance, aging, carrying out filtration washing and drying to obtain a porous material with the specific surface area being not less than 150m<2> / g, the pore volume being not less than 0.2ml / g and the most probable aperture of meso pores being 4-20nm.

Description

technical field [0001] The invention relates to a method for recovering rare earth from rare earth-containing catalyst waste and comprehensively utilizing the waste, belonging to the field of resource recycling. Background technique [0002] Since scientists discovered that Y-type molecular sieves exchanged with rare earths have better thermal and hydrothermal stability in the 1960s, catalysts with rare earth Y-type molecular sieves as active components have been widely used in fluidized catalytic devices in the field of petroleum refining. (FCC), to obtain higher yields of gasoline, diesel, etc., my country also began to use FCC catalysts containing rare earth molecular sieves in the late 1970s. At present, only about 180,000 tons of FCC catalysts are used in my country every year. Due to different types, the rare earth content in most FCC catalysts is between 0.5% and 8%, and the amount of rare earth chloride used on FCC catalysts reaches 13,000 tons per year. . [0003] B...

AI Technical Summary

Problems solved by technology

[0004] For the above-mentioned waste materials, Chinese patent ZL200510046121.0 announced the use of spent molecular sieve catalysts and hydrochloric acid to prepare polyaluminum chloride, but it did not involve the recovery of rare earths, and there was still a large amount of silicon-containing waste residue produced; Chinese patent ZL200910241671.6 announced A method for recovering rare earths from silicon-aluminum materials containing rare earths (including molecular sieves loaded with rare earths or catalyst waste), using acid selective preferential leaching to dissolve most of the rare earths and a small amount of aluminum and separate impurities such as silicon, and then use double salt Precipitation or oxalic acid precipitation method makes rare earth precipitate and separate from aluminum, recovers and purifies rare earth, in order to reduce the leaching of aluminum, it is necessary to roast the silicon-aluminum material to reduce the activity of aluminum; however, there is still a large amount of silicon-containing waste residue in the process

[0005] There are also reports to synthesize fresh molecular sieve products using FCC spent catalysts as raw materials (Yang Guidong et al., using spent catalyst cracking catalysts as raw materials to synthesize NaY molecular sieves, Journal of Inorganic Chemistry, February 2009). Sodium hydroxide was roasted at 750 °C for 45 hours, and deionized water, pretreated spent catalyst, silica sol, and transparent liquid phase director were slowly added to a 100 mL beaker in order to obtain the composition Na 2 O:Al 2 o 3 : SiO 2 :H 2 O=3.4:1.0:4.0:120 silica-alumina gel, hydrothermally crystallized at 100 °C for 10 h, and finally filtered, washed, and dried to obtain a specific surface area of ​​615 m 2 / g fresh NaY molecular sieves, but also not involved in the recovery of rare earths in the catalyst