Selective Separation and Comprehensive Recovery of Nickel in Alkaline Chemical Nickel Wastewater

Abstract

A selective separation and comprehensive recovery method for nickel in alkali chemical nickel waste water, comprising: (1) stage I adsorption: pumping filtered alkali chemical nickel waste water into a stage I adsorption column filled with a type A adsorbent, and enabling absorption to remove Ni; (2) stage II absorption: pumping effluent water in stage I absorption in step (1) into a stage II absorption column filled with a type B adsorbent, and enabling absorption to remove the remaining Ni; (3) stage II pre-regeneration: after breakthrough of the stage II absorption column in step (2), enabling countercurrent pumping of a regenerant into the stage II absorption column for pre-regeneration, and enabling circulative pumping of effluent water after elution into the stage II absorption column for elution; (4) stage II regeneration: after the pre-regeneration in step (3) is finished, enabling countercurrent pumping of the regenerant into the stage II absorption column for regeneration, and discharging effluent water after elution to obtain a stage II regeneration desorption solution; (5) stage I pre-regeneration: after breakthrough of the stage I absorption column in step (1), enabling countercurrent pumping of the stage II regeneration desorption solution generated in reactions in step (4) into the stage I absorption column for pre-regeneration, and enabling circulative pumping of effluent water after elution into the stage II absorption column for elution; (6) stage I regeneration: after the pre-regeneration in step (5) is finished, enabling countercurrent pumping of the regenerant into the stage I absorption column for regeneration, and discharging effluent water after elution to obtain a stage I regeneration desorption solution; and (7) comprehensive recovery of Ni: mixing the stage I regeneration desorption solution generated in step (6) with an alkali chemical nickel high-concentration aging solution, and enabling comprehensive recovery of Ni by mean of neutralization precipitation or electrocatalytic reduction.

Description

technical field [0001] The invention discloses a selective separation and comprehensive recovery method for nickel in alkaline chemical nickel wastewater, belonging to the field of resource treatment of heavy metal wastewater. Background technique [0002] Alkaline electroless nickel plating has the advantages of wide adaptability, good stability of plating solution, fast plating speed and high coating quality, and has become an ideal system to replace acidic electroless nickel plating. However, the large amount of washing water consumption caused by the cleaning of the plated parts and the high-concentration waste liquid discharge caused by the aging of the plating solution have greatly limited the application of alkaline electroless nickel plating. Therefore, how to effectively realize the water saving and pollution reduction of alkaline electroless nickel plating has become a key point in the promotion of this technology. Nickel is a carcinogenic and allergenic pollutant...

AI Technical Summary

Problems solved by technology

Although this method can effectively recover nickel in low-concentration wastewater, it has no selectivity for the adsorption of nickel, and it is still difficult to meet the standard for effluent

Although the above methods can realize the recovery of nickel, each has its own limitations.

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