A method of ion-exchanging solid substances containing exchangeable ions

Abstract

The invention provides an ion exchange method for a solid substance with exchangeable ions, which includes the following steps: bipolar membrane electrodialysis: performing bipolar membrane electrodialysis to a water solution with ions, so as to obtain an acid liquor; ion exchange: performing ion exchanging to the contacted solid substance with exchangeable ions and the acid liquor, wherein ions capable of forming a water insoluble substance with OH<-> are contained in the exchangeable ions in the solid substance; solid-liquid separation: performing solid-liquid separation to slurry of the solid substance subjected to ion exchange, so as to obtain the solid phase and the liquid phase; performing solid-liquid separation after the pH value of the liquid phase is adjusted above 8 and obtaining a conditioning fluid; circulating the conditioning fluid to the step of bipolar membrane electrodialysis, substituting at least part of the water solution with ions with the conditioning fluid for bipolar membrane electrodialysis. In the method provided by the invention, power consumption for bipolar membrane electrodialysis is low, and higher ion exchange efficiency is obtained through the method.

Description

technical field [0001] The invention relates to a method for performing ion exchange on a solid substance containing exchangeable ions, in particular to a method for performing ion exchange on a solid substance containing exchangeable ions in a clean and low-cost manner. Background technique [0002] According to the data of the Ministry of Water Resources in 2005, 78% of the river sections flowing through cities in the country are no longer suitable for drinking water sources, and 50% of urban groundwater is polluted. Water pollution will not only directly affect industrial and agricultural production, but also cause serious harm to human health. In order to achieve the sustainable development of the country and the harmonious coexistence between man and nature, the country has formulated the national standard GB8978-1996 for industrial sewage discharge, which stipulates that the primary discharge standard of ammonium nitrogen in the petrochemical industry is 15mg / L, and th...

AI Technical Summary

Problems solved by technology

However, the common problem of the ammonium exchange method is that the original powder of the molecular sieve needs to be exchanged with ammonium to make an NH4 molecular sieve, and then roasted to convert it into a hydrogen molecular sieve. However, due to the limitation of the chemical balance, NH4+ cannot completely replace the Na at one time. + , to get low Na 2 Molecular sieve with O content, the ammonium exchange process needs to be repeated many times, resulting in a large amount of ammonium nitrogen waste water exceeding the standard

In order to meet the national standard that the discharge of ammonium nitrogen is less than 15mg / L, wastewater needs to be treated, but the process of treating the wastewater not only consumes a lot of energy but also costs a lot

In addition, the conventional ammonium ion exchange method needs to repeatedly adjust the acidity and alkalinity of the environment, the operation is complicated and the efficiency is low

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