Treatment method for high-ammonia-nitrogen wastewater containing manganese and uranium

Abstract

The invention relates to a treatment method for high-ammonia-nitrogen wastewater containing manganese and uranium. The treatment method comprises the following steps: (1) mixing quicklime and water, and performing stirring to a uniform slurry shape to obtain lime slurry; (2) returning sediment obtained in the step (1) to the step (1) when next operation is performed; (3) adding a soluble carbonateinto a supernatant obtained in the step (1) to remove a certain amount of calcium ions; (4) performing ultrafiltration on a filtrate obtained in the step (3), and introducing the obtained substance into a gas film device; and (5) performing evaporation concentration on an absorption liquid obtained in the step (4) to a saturated solution, performing crystallization to obtain a corresponding ammonium salt product, merging the crystallization mother liquid with a next-time absorption liquid, performing evaporation concentration, and performing crystallization. According to the treatment methodprovided by the invention, removal of harmful elements such as the manganese and the uranium in the wastewater is realized, so that qualified discharge of the wastewater is guaranteed; and the ammonianitrogen in the wastewater can be used to prepare by-products such as ammonium sulfate, ammonium chloride, ammonium nitrate, ammonium phosphate and ammonia water, so that the purpose of recycling ofwaste is realized.

Description

technical field [0001] The invention belongs to the technical field of uranium resource extraction and three-waste treatment, and in particular relates to a treatment method for high-ammonia nitrogen manganese-containing uranium wastewater. Background technique [0002] In the production process of natural uranium, the preparation of nuclear pure compounds from ores has to go through many processes such as ore grinding, leaching, extraction, purification and refining, which will produce a large amount of radioactive waste water. Wastewater often contains harmful impurities such as ammonia nitrogen, manganese ions, and uranium elements, and sometimes the concentration of ammonia nitrogen is high, which can reach more than 500mg / L. It can neither be returned to the production process nor directly discharged into the water body to pollute the environment. For the treatment of this kind of wastewater, there is still a lack of economical and effective means, resulting in the accu...

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Problems solved by technology

However, the two methods usually can only reduce the ammonia nitrogen in the wastewater to a certain concentration, and it is difficult to directly meet the discharge standard. They also need to be combined with other low-concentration ammonia nitrogen treatment methods, resulting in a lengthy and complicated process.

Moreover, there are many factors affecting the removal efficiency of ammonia nitrogen, especially in the winter of blowing off method, due to the low temperature, its efficiency will be greatly reduced, which often affects the normal operation of the process

In addition, the gas containing ammonia nitrogen cannot be directly discharged into the atmosphere, and an absorbent must be used for absorption to ensure that the concentration of ammonia nitrogen in the discharged gas reaches the standard, which further increases the complexity of the process

[0005] On the whole, there is currently a lack of corresponding research on the treatment of radioactive wastewater containing uranium, manganese, and high concentrations of ammonia nitrogen, and there is no established treatment process, which makes it difficult to implement this type of wastewater treatment. With the accumulation of water , the environmental risks are gradually increasing, which poses further challenges to the construction of green uranium mines in my country

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