The EFZERO gold refining plants, produced by Italimpianti Orafi, can refine all kind of gold alloys without development of any sort of acid fumes and with recovery of nitric acid.

The typical gold content of the incoming gold alloys is about 50-99 % (initial purities below this value will reduce the production capacity) with a maximum Silver content up to 20% by feeding thin powder (normally the max content of silver is 12-13 % by feeding grain).

EFZERO gold refining plant can be fed with grain or better with thin powder (150-600 micron). The powder is the most efficient solution in order to increase the exposed surface area thus making the process faster and reducing the quantity of undissolved gold, compared with the standard grains.

This system is constituted by a glass reactor with mixer, a dosing system for gold powder (optional) and a special system for fumes treatment and recovery of nitric acid.
Thanks to the innovative solutions, this unit will guarantee a great number of advantages such as:

  • Reduction of chemicals consumption
  • Reduction of reaction time
  • Reduction of acidic fumes emissions
  • Recovery of nitric acid
  • Higher process efficiency: allowed quantity of silver content in the alloy to refine up to 20%
  • Reduction of manpower for control and operations

The system is completed with a special atomizing unit to produce thin Gold powder.
Other optional units are the automatic dosing system for gold powder and the detector for end-of-process of the Aqua Regia reaction.

Zero Emissions Process with Regeneration of Nitric Acid

The acid fumes produced during the dissolution process will be treated with a washing scrubber and a gasometer unit: the first unit will eliminate the HCl/Cl2 gases, then the gasometer will oxidize the nitrous oxides (NOx) and generate nitric acid HNO3 to be reused in the following processes. This system will eliminate the emissions in the atmosphere (close loop) in order to reduce the environmental impact giving a substantial to support the circular green economy.
The Fume scrubber (our model TLF) will be used to neutralise the acid fumes, produced during the refining process, only in case of emergency.

(Width x Depth x Height)
IAO/ZE20 4 kW 6 kg 3300x2400x2545 mm
IAO/ZE20-20 8 kW 12 kg 4000x2400x2545 mm
IAO/ZE50 5 kW 15 kg 3500x3450x2550 mm
IAO/ZE50-50 9 kW 30 kg 4200x3300x2550 mm



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