Recycling method for saponified ammonium-sulfate wastewater in rare soil

Abstract

The invention provides a recycling method for saponified ammonium-sulfate wastewater in rare soil. The recycling method comprises the following steps: (1) pretreatment of coagu-flocculation reaction and a precipitation tank is carried out on the ammonium-sulfate wastewater; (2) an ultrafiltration system is adopted; (3) an electrodialysis system is adopted, concentrated water treated by the electrodialysis system enters the step (4), and fresh water enters the step (5) for treatment; (4) an MVR (Mechanical Vapor Recompression) system is adopted, concentrated salt water treated by the MVR system is crystallized and then becomes solid salt which is used as a composite fertilizer material or is sold to outside as a side product, and evaporated and condensed water is directly reused as process water for sulfuric-acid extraction in a rare-soil saponifying process; and (5) the fresh water electrodialyzed in the step (3) is treated by using a nanofiltration system, the permeated liquid of the nanofiltration system is used as the process water, and the concentrated liquid returns to the step (3) and is added into electrodialyzed water. The recycling method provided by the invention has the advantages that comprehensive treatment can be carried out on the ammonium-sulfate wastewater in the rare soil, so that not only can the environmental burden be caused, but also the ammonium-sulfate wastewater can be recycled.

Description

technical field [0001] The invention relates to a rare earth smelting ammonium sulfate wastewater treatment technology. Background technique [0002] As a strategic resource, rare earth has been highly valued by many countries in the world. Although the proportion of my country's rare earth industry in the entire national economy is very small, with an annual output value of less than 1 billion US dollars, it has been highly valued by government departments at all levels because of its unique strategic position, especially in the past 10 years. With the development of rare earth products in many application fields, the state pays more and more attention to the rare earth industry. Industrial policies have been introduced many times, which on the one hand promotes the overall structure optimization of the rare earth industry, and on the other hand promotes the development of the rare earth industry. Rare earth smelting is the main method in the separation of rare earths. It o...

AI Technical Summary

Problems solved by technology

Although the first three methods have played a good role in dealing with rare earth smelting, there are still complex structures, large investment, large land occupation, high operating costs, high energy consumption, difficult maintenance and operation, and sewage purification to varying degrees. The effect is poor, only the treatment reaches the standard discharge, water and other resources cannot be recycled and cannot reach the final treatment, etc.

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