Method for recycling copper from copper nitrate waste water

Abstract

The invention discloses a method for recycling copper from copper nitrate waste water. The technical key points of the invention are that: an iron rod is taken as an insoluble anode; a copper plate is taken as a cathode; and gas stirring is performed on the copper nitrate waste water in an electrolytic bath, so that an electrolytic process can be operated continuously. The purity of the copper recycled by the method is over 99.97 percent, and the recovery rate of the copper is over 99.5 percent. The method has the advantages of short process flow, simple operation, simple equipment, low equipment requirement, low investment and particular suitability for the realization of the recycling of the copper from the copper nitrate waste water in small and medium-sized enterprises.

Description

technical field [0001] The invention belongs to the field of electrochemical applications, in particular to a method for recovering copper from copper nitrate wastewater. Background technique [0002] Copper nitrate wastewater widely exists in the fields of electroplating and powder metallurgy. At present, the method of recovering copper from copper nitrate wastewater generally adopts precipitation-electrolysis method and displacement-electrolysis method. [0003] Among them, the precipitation-electrolysis method is used to reclaim copper in copper nitrate wastewater. The precipitant generally used is sodium carbonate. The method is to add sodium carbonate solution to copper nitrate wastewater, and the copper ions are precipitated. After precipitation, filtration, cleaning, After drying, hydrogen reduction is carried out, and the reduced blister copper is smelted and cast into plates, and then electrolytically purified. Adopt this method, recovery process is loaded down wit...

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Problems solved by technology

[0011] Can find out that this method has following shortcoming from above-mentioned 4 aspect characteristics, and this method is only applicable to the recovery of copper in the copper nitrate solution that nitric acid content is higher (nitric acid content is greater than 80g / L), and, if copper nitrate concentration is relatively low , the copper nitrate solution needs to be concentrated, and the concentration of the concentrated solution has different requirements. For example, as can be seen from the examples, the initial concentration of the copper nitrate electrolyte is required to be 120g / L, and the concentration of the supplementary solution is required to be 210g / L , its technological process and tooling equipment are more complicated, not as simple as described in the invention

And for the copper nitrate solution that acidity is very low (content of nitric acid is less than 6.3g / L), adopt this method to reclaim copper and obviously do not meet its technological condition; If the solution is concentrated, the cost will be greatly increased. Whether this method is suitable needs further demonstration

In addition, the copper recovered by this method is deposited on the cathode of the stainless steel plate. The combination of the two is similar to the combination of electroplating, so the combination of the two is very strong, so that the copper is scraped off from the cathode of the stainless steel plate, and the stainless steel shavings are often scraped off differently. , leading to poor purity of recovered copper

[0012] In addition, iron is a cheap and easy-to-obtain material, but using iron as an anode will be dissolved quickly after being immersed in the electrolytic solution, losing its function as an anode, and once the iron is dissolved, the formed iron ions will be in the The conversion of ferrous iron and ferric iron between cathode and anode directly consumes a large amount of electric energy. Therefore, there is no research report on using iron as an anode to recover copper at home and abroad.

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