Ammonia → Ammonium Hydroxide

Participants

Reaction Steps

For the preferred copper-sulfate system, the leach solution 10 containing dissolved copper-ammonia-sulfate is next ammoniated or pressurized with ammonia (E) or aqueous ammonia which can be recycled 11 and 16 from subsequent steps. It has been unexpectedly discovered that the mineral values, which were dissolved as a complex with ammonia, precipitate as a complex when pressurized with ammonia. The soluble complex copper ammine sulfate solution enters a low pressure ammoniator (Step E) where ammonia is used to precipitate an insoluble complex ammine. The complex is precipitated by the application of low pressure ammonia. The slurry is filtered (Step F), leaving the solid copper ammine sulfate wet with NH4OH. The gas-liquid stream 13 is recycled. No washing of the complex is necessary. Typically, more than 99 percent of the copper is precipitated in this step.

Provenance & Evidence