Metso Full portfolio Elution and Goldroom plant
The Metso Elution and Goldroom plant can be delivered standalone or as part of a holistic gold process solution to enable onsite production of gold doré.
The elution plant is built from pre-engineered modules to reduce engineering, delivery, construction, and commissioning time and cost. The plant also features a heat recovery circuit to minimize energy consumption and efficient carbon dewatering to maximize carbon regeneration and minimize energy losses.
metso outotec elution goldroom plant
Key benefits
  • Based on standardized, pre-engineered modules to reduce CAPEX, optimize delivery lead time
  • Simple to operate thanks to extensive automation options
  • Complete performance guarantee with risk mitigation based on advanced dynamic modeling
  • Safe, efficient training available via virtual plant simulation platform
A compact, flexible, and efficient turnkey solution

The Elution and Goldroom plant completes the CIL/CIP/CIC circuit, enabling stripping of gold from loaded carbon, electrowinning into gold sludge, and drying and smelting of sludge into doré bars. Carbon can then be reactivated for reuse in the circuit.

Metso’s turnkey process plant solution includes:

  • Acid wash step to remove inorganic compounds from carbon
  • Elution step to strip gold from loaded carbon
  • Electrowinning to precipitate gold sludge
  • Drying and smelting step to produce doré bars
  • Regeneration step for thermal reactivation of carbon
  • A dedicated water treatment circuit


metso outotec goldroom elution plant

Plant flowsheet designs

Metso offers compact plant flowsheet designs based on either ZADRA or AARL technologies. The process comprises three carbon dewatering screens, two columns with supporting tanks, a heater skid, an electrowinning circuit with supporting tanks and filters, a drying/calcining oven, and a smelting furnace with ancillary goldroom tools. The plant also includes a carbon regeneration kiln with supporting tanks, settler, process water tank, and carbon fines filter press.

aarl flowsheet
Metso AARL circuit

Energy-efficient operation to cut costs

The elution plant includes an enlarged heat recovery circuit that optimizes solution temperature and flows, minimizing elution time and, energy consumption. Efficient carbon dewatering maximizes carbon regeneration and minimizes energy losses.

Customizable automation to suit your process needs

The elution plant is available with four levels of automation and can be controlled either from a standalone control room or via the plant’s DCS system.

  • With standard automation, the plant is controlled locally by an operator. Standard automation includes elution carbon regeneration temperature control and monitoring of various tank level, temperature, and pressure parameters.
  • With upgraded automation, the plant can be remotely operated. Upgraded automation includes all the functionalities of basic automation plus automated cycle sequencing.
  • With advanced automation, the operator is only required to initiate cycle prompting. Advanced automation adds automated carbon transfer systems, circuit sequence startup, and column-level measurements.
  • With premium automation, no cycle prompting is required from the operator. Premium automation adds pH control during acid wash, reagent makeup, dosing, and intelligent monitoring of all process flows.

Metso can dynamically model the plant’s acid wash, elution, and electrowinning circuits using our proprietary HSC Chemistry® software to enable variability analysis and scenario planning.

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