Method for extracting rare earth from rare earth-containing sludge

Abstract

The invention provides a method for extracting rare earth from rare earth-containing sludge. The method comprises the following steps: 1, allowing the rare earth-containing sludge to contact with an acidic aqueous solution in order to leach the rare earth-containing sludge, and separating to obtain a rare earth element-containing leachate; and 2, allowing the leachate to contact with an organic solvent containing an extraction agent, and extracting to obtain a raffinate water phase and a rare earth element-containing extraction organic phase, wherein the extraction agent is a phosphorus-to-oxygen double bond-containing phosphorus-containing extraction agent, carboxylic acid extraction agent and sulfur-to-oxygen double bond-containing sulfur-containing extraction agent mixture. The method allows rare earth to be leached and extracted from the rare earth-containing sludge in a high yield mode and rare earth chloride to be prepared, the recovered rare earth chloride can be used for producing catalysts, and the method has the advantages of simple whole process, environmental protection, low energy consumption, less production device investment and low operating cost.

Description

technical field [0001] The invention belongs to the technical field of secondary resource utilization of rare earth-containing sludge, and more specifically relates to a method for extracting rare earth from rare earth-containing sludge produced in the production process of a catalytic cracking catalyst. Background technique [0002] my country's petrochemical industry has been producing and using rare earth molecular sieve catalysts since the mid-1970s. With the increase of crude oil processing and the expansion of catalytic cracking production capacity, the consumption of cracking catalysts is increasing. Sinopec is a major manufacturer of catalytic cracking catalysts. During the "Twelfth Five-Year Plan" period, the annual output reached more than 200,000 tons. At present, Sinopec uses rare earth chloride as the rare earth raw material for catalyst production. [0003] In catalyst production enterprises, in order to meet the national environmental protection requirements...

AI Technical Summary

Problems solved by technology

[0004] CN101481161A discloses a method for producing rare earth aluminum iron polysilicon sulfate with rare earth sludge and iron dust sludge, but it only involves the production of rare earth aluminum iron polysilicon sulfate by rare earth sludge and iron dust sludge, not directly Extraction of valuable rare earths or their compounds limits their scope of application