Method for treating rare earth production tail water by utilizing abandoned mining pit

Abstract

The invention discloses a method for treating rare earth production tail water by using an abandoned mining pit. The method comprises the following steps: 1) spreading waterproof canvas on the inner surface of the mining pit to form a water collecting space; 2) pumping high-ammonia-nitrogen rare earth mining tail water from a water inlet of the mining pit every day; 3) adding microbial thalli; 4)introducing oxygen into the mining pit, and controlling the dissolved oxygen content to be 1.5-2 mg / L; 5) when the concentration of ammonia nitrogen in the mining pit exceeds 15 mg / L, continuously supplementing microbial thalli into the mining pit; 6) when the ammonia nitrogen index of the rare earth mining tail water in the abandoned mining pit does not exceed 15 mg / L, achieving up-to-standard discharge, and achieving overflow water outlet through daily water inlet; and 7) in the tail water treatment process, enabling a large number of beneficial microorganisms to grow to form flocs which canbe used for raising fries. The abandoned mining pit with low field environment cost is utilized, meanwhile, high-concentration ammonia nitrogen tail water generated by rare earth mining can be efficiently treated, and the problem of pollution to the environment is relieved.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, and in particular relates to a method for treating rare earth production tail water by utilizing an abandoned mine pit. Background technique [0002] In the in-situ rare earth mining process, due to the use of sodium sulfate leaching technology, the high ammonia nitrogen rare earth mining tail water after mine closure contains only nitrogen sources and lacks carbon sources due to the extremely high concentration of pollutants (2000-3000mg / L). The serious imbalance of carbon-nitrogen ratio and the acidification of water quality after ammonia nitrogen removal lead to unsatisfactory cost and effect of current treatment technology. Contents of the invention [0003] The object of the present invention is to provide a method for treating rare earth production tail water by using abandoned mine pits in view of the above phenomenon. [0004] In order to achieve the above object, the present ...

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Problems solved by technology

[0002] In the in-situ rare earth mining process, due to the use of sodium sulfate leaching technology, the high ammonia nitrogen rare earth mining tail water after mine closure contains only nitrogen sources and lacks carbon sources due to the extremely high concentration of pollutants (2000-3000mg / L). The serious imbalance of carbon-nitrogen ratio and the acidification of water quality after ammonia nitrogen removal lead to unsatisfactory cost and effect of current treatment technology