Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

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Convert Copper Nitrate into Copper Oxide (10 replies)

Raje Singh
8 years ago
Raje Singh 8 years ago

Is there any suitable oxidizing agent for conversion of copper nitrate into copper oxide which will be useful in separation of copper from silver nitrate electrolyte in HSSR process?

Marshal Meru
8 years ago
Marshal Meru 8 years ago

You are asking the wrong question. No oxidizing agent is necessary because the copper is already fully oxidized. What you apparently want is a method to selectively remove copper ions from the silver nitrate electrolyte.

Bob Mathias
8 years ago
Bob Mathias 8 years ago

No oxidizing agent is needed. Cu(NO3)2 is cupric as is CuO. What pH is the solution? Raise the pH above 9 with NaOH to precipitate Cu(OH)2. Wash the precipitate with pH 9 NaOH solution to remove entrained nitrate.

Sachin Prakash
8 years ago
Sachin Prakash 8 years ago

Both are correct in terms of the higher valence state of Cu+2; however, adding NaOH will precipitate grayish Ag2O in addition to bluish green Cu(OH)2; iX resins (Dow) would be a viable path for the separation. A more convoluted process would entail adding stoichiometric amounts of dilute HCl (excess will form the soluble [AgCl2]- complex), liquid-solid separation followed by washing & drying of the AgCl residue; smelting of the solids w/borax & flour. The metal may then be dissolved in conc. HNO3 to produce AgNO3.

Raje Singh
8 years ago
Raje Singh 8 years ago

SORRY, I want to convert copper(ii) nitrate into copper(ii) oxide in the effluents at a single stretch without passing through Cu(OH)2. Is there any reagent there for such conversion?

Marshal Meru
8 years ago
Marshal Meru 8 years ago

If the copper solution is very hot i.e. 80 degrees C, then CuO will form directly when the NaOH is added. To follow up on your point it is possible to precipitate copper ions with Ferro-cyanide ion. I don't know if silver ion will also precipitate but I doubt it will.

Oberstorm
8 years ago
Oberstorm 8 years ago

I admit to being confused both by the question and by some of the answers (believing that copper nitrate was time-and-a-half). But anyway in the simplistic sense and answering "I want to convert copper(ii) nitrate into copper(ii) oxide" the vehicle to this transformation is heat:

2 Cu(NO3)2 → 2 CuO + 4 NO2 + O2
This will also decompose AgNO3 in the same manner (to Ag2O)

However, I suspect that we're not getting enough information. I suspect you want to recover copper free of silver (or vice versa). Both form ammoniac ammine complexes so this wouldn't be an effective separation route. Either froth flotation or solvent extraction (with the appropriate LIX reagent) suggests themselves.

Now you could add sodium chloride (precipitating the silver nitrate as AgCl) as in the common analytical chemistry route and test for silver. The Cu2+ would remain in solution.

Marshal Meru
8 years ago
Marshal Meru 8 years ago

I believe the objective is to reduce the copper concentration in a silver nitrate electrolyte. The copper concentration must be getting pretty high to cause problems with silver electro-refining.

(unknown)
8 years ago
(unknown) 8 years ago

Copper II nitrate decomposes to Copper II oxide plus nitrogen dioxide and oxygen at about 180C. The nitrogen dioxide readily combines with water to produce nitric acid and nitric oxide.

Marshal Meru
8 years ago
Marshal Meru 8 years ago

Do you think that the copper contaminated silver nitrate electrolyte could be treated in a pressure vessel at 180C and produce CuO? This would be an elegant solution to your problem.

U
Unterstarm
8 years ago
Unterstarm 8 years ago

I agree; you can see a detailed explanation in United States patent US 8,282,903 B2

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