Method for comprehensive reuse treatment of rare-earth sodium saponification wastewater

Abstract

The invention provides a method for comprehensive reuse treatment of rare-earth sodium saponification wastewater. According to the method, the sodium saponification wastewater is firstly subjected to precipitation, ultrafiltration and degreasing pretreatment, and then, an electrodialysis system, a mechanical vapor recompression (MVR) system and nanofiltration treatment are adopted. According to the method, a pretreatment, membrane integration and MVR integrated technology is adopted to treat rare earth smelting wastewater in an innovative manner, final permeate is reused to production, the smelting wastewater is subjected to concentration and desalination by using respective characteristics of ultrafiltration, electrodialysis, a nano-filtration membrane and MVR, saline matters in the wastewater are transformed into solid crystals, desalinated water can be reused as pure water, and the wastewater and an extractant can be recovered, so that water resources are recycled; on the premise that a relatively high extractant and water recovery rate is achieved, industrial production operation is finally realized more economically, so that benefits for enterprises are created, the production and operating costs are lowered by over 30%, and the market competitiveness of rare earth smelting enterprises is improved.

Description

technical field [0001] The invention relates to a process for comprehensive recycling of rare earth sodium saponification wastewater. Background technique [0002] As a strategic resource, rare earth has always been highly valued by many countries in the world. Although my country's rare earth industry accounts for a very small proportion in the entire national economy, with an annual output value of less than 1 billion US dollars, due to its unique strategic position, it has been highly valued by government departments at all levels, especially in the past 10 years. With the development of rare earth products in various application fields, the state has paid more and more attention to the rare earth industry, and has issued several industrial policies to promote the optimization of the overall structure of the rare earth industry on the one hand, and the development of the rare earth industry on the other hand. Rare earth smelting is the main method in rare earth separation...

AI Technical Summary

Problems solved by technology

Domestic rare earth smelters generally use acid-base neutralization as waste water and discharge it up to standard, which not only wastes resources, but also increases the burden of environmental protection

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