Recovery method of rare earth oxalate precipitation wastewater

Abstract

The invention relates to a recovery method of rare earth oxalate precipitation wastewater. The method is characterized in that the rare earth oxalate precipitation wastewater and hydrochloric acid are prepared into a solution, wherein the concentration of oxalate is 0.01-10g / L, and the concentration of H<+> is 3.5-6mol / L. According to the method provided in the invention, the rare earth oxalate precipitation wastewater and hydrochloric acid are prepared into a solution for back extraction of rare earth from a rare earth loaded extraction solution. Therefore, the wastewater discharge problem is solved, and the acid needed by back extraction of rare earth and the oxalic acid required by final rare earth precipitation can also be saved.

Description

technical field

[0001] The invention relates to a recovery method of oxalic acid rare earth precipitation wastewater. Background technique

[0002] Since the mid-1980s, my country's rare earth industry has developed rapidly and made great achievements. However, rare earth smelting belongs to wet smelting, and the amount of wastewater is relatively large, and the wastewater has the characteristics of serious pollution and difficult treatment. Rare earth smelting will bring about major environmental problems.

[0003] Rare earth production mainly includes processes such as dissolution, extraction, stripping, and precipitation. The dissolution process mainly involves dissolving oxidized rare earths or rare earth carbonates into rare earth chlorides with hydrochloric acid. The extraction process is to use the difference in extraction performance between the extractant and the rare earth elements to extract the easy-to-extract rare earth into the extractant to form an extractant...