Technology for removing mercury in contaminated acid wastewater

Abstract

The invention discloses a technology for removing mercury in contaminated acid wastewater. The method specifically comprises the following steps of pumping contaminated acid wastewater produced in a sulfuric acid dynamic wave scrubbing process into a reaction tank, adding a strong oxidant KMnO4, then adding lime milk for reaction, and then adding sodium sulphide for reaction; adding a flocculating agent, namely polyacrylamide into ore pulp after mercury removal, pumping the liquid into a plate and frame filter after the reaction to obtain filter liquor and filter residues, wherein the content of Hg in the obtained filter liquor is detected to be less than 0.03mg / L, and the content of the mercury in the filter residues is 0.264 to 20.33 percent, and collecting the filter residues. By adopting the technology provided by the invention to treat contaminated acid produced in the sulfuric acid dynamic wave scrubbing process of the lead and zinc smelting industry to remove the Hg, the wastewater discharging reaches the standard, the operation is simple and reliable, and a production field test result shows that the novel technology is feasible technically. By using the technology in production practice for two years, the problem that the Hg in the contaminated acid produced by lead and zinc smelting does not reach the standard is thoroughly solved. By adopting the technology provided by the invention to remove the mercury, the fact that the Hg of discharge water is less than or equal to 0.03mg / L is guaranteed, and a method through which the discharge reaches the standard is realized.

Description

technical field [0001] The invention belongs to the technical field of lead-zinc smelting, relates to the removal of mercury from polluted acid produced in the sulfuric acid dynamic wave washing process, and in particular to a process for removing mercury from polluted acid wastewater. Background technique [0002] The source and characteristics of dirty acid wastewater: dirty acid wastewater comes from sulfuric acid dynamic wave washing in the process of lead-zinc smelting, and has the characteristics of high Hg, high F and high COD. In particular, the Hg concentration is generally 20-2000mg / L, mainly in the form of suspended particulate mercury, ionic mercury, and colloidal mercury, with elemental mercury, monovalent mercury, and divalent mercury in the valence state. And with the change of ore source, the mercury in the zinc concentrate fluctuates greatly, resulting in a large fluctuation of Hg in the sewage acid wastewater, which brings great difficulty to the subsequent...

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Problems solved by technology

And with the change of ore source, the mercury in the zinc concentrate fluctuates greatly, resulting in a large fluctuation of Hg in the sewage acid wastewater, which brings great difficulty to the subsequent wastewater treatment

[0003] General treatment methods of polluted acid wastewater: such as figure 2 As shown, the main method for treating mercury in sewage acid wastewater in China is the vulcanization-neutralization precipitation method. The general treatment process is as follows figure 1 As shown, there are problems in the traditional vulcanization-neutralization method: the vulcanization-neutralization precipitation method can only remove ionic mercury in water, but cannot treat suspended particulate mercury and colloidal mercury in water, and the Hg compliance rate of treated wastewater is low and unstable. In particular, it cannot meet the requirement that the Hg standard of the current effluent wastewater has dropped from the original 0.05mg / L to the current 0.03mg / L

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