Mine acid wastewater utilization and deep purification method

Abstract

The invention relates to a mine acid wastewater utilization and deep purification method which comprises the following steps: (1) adjusting the pH value of mine acid wastewater using a neutralizer to recover gypsum; (2) recovering iron through two-stage neutralization; (3) recovering copper and zinc through an efficient vulcanization reaction; (4) leaching the copper and zinc residue with acid and separating copper and zinc to obtain a zinc sulfate solution and copper-rich residue; recovering the vulcanizing agent; drying the zinc sulfate solution by an MVR technology to prepare zinc sulfate; and applying the vulcanizing agent to the step (3) for the efficient vulcanization reaction; and (5) performing deep treatment and reusing the effluent or discharging when the effluent reaches the standard. By adopting the method, the recovery efficiency of copper in the mine acid wastewater can reach 85% or more, and the recovery rate of zinc is 95% or over while high-purity gypsum can be produced at the same time; compared with traditional technology, the residue quantity can be reduced by 20% or over, and the utilization of the mine acid wastewater is realized; and the new technology has the advantages of efficient purification and low cost and brings remarkable economic and environmental benefits.

Description

technical field [0001] The invention relates to a waste water treatment process, in particular to a mine acid waste water recycling and deep purification method. It is suitable for the treatment of acidic wastewater produced in copper sulfide mining and biological wet copper extraction process. Background technique [0002] In the process of copper sulfide mining and biological wet copper extraction, the main characteristics of the mine acid wastewater are low pH value, many types of metal ions, high concentration of copper, zinc, iron and sulfate, and low pH value. In 1.6, the iron ion content is higher than 7g / L, the sulfate radical concentration reaches 20g / L, and the copper and zinc ion content is 90-300mg / L. If the acidic mine wastewater is discharged into the farmland, the crops will turn yellow and the soil will be salinized; if it is discharged into the water body, it will harm fish and other aquatic organisms, and harm the human body through the food chain. [000...

AI Technical Summary

Problems solved by technology

The microbial treatment of acidic mine wastewater by using sulfate-reducing bacteria has the advantages of low cost, strong applicability, no secondary pollution, and recyclable valuable components. The range is small, the tolerance to metal ions is poor, the treatment efficiency is low, and it is not suitable for the treatment of high-concentration acidic wastewater, so it has not been widely used.

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