Pueblo Viejo – Pressure Oxidation & Air Separation Project

Barrick Gold Corporation and Goldcorp Inc. | Dominican Republic | 2006–2012

4 largest

autoclaves in the world by weight (2,178 tonnes)


sulphur-oxidation capacity to date (over 500 kt S/yr)

Award of Merit

Consulting Engineers of Ontario

1.125 million

ounces of gold per annum for the first 5 years


  • The double refractory and polymetallic characteristics of this gold ore make it one of the most complex to process in the world
  • Production is expected to average 1.125 million ounces of gold per annum for the first five years. The final design capacity is 24 000 t/d, using four autoclave trains
  • The fabrication and transport of these autoclaves required innovative solutions due to logistical challenges posed by their diameter and length


  • Full EPCM program for the core part of the gold refractory process (pressure oxidation and oxygen plant) began in 2008
  • The pressure oxidation area included autoclave vessels and auxiliary components; slurry preheat vessels; pressure let-down vessels; vent gas cyclones; vent gas quenching; gas scrubbing; and related support services and utilities
  • The autoclaves were designed, selected, and had specified linings and installation requirements.
  • Managed construction of the supplier-designed 4,000 t/d oxygen plant (99.5% gas purity, and 45-bar delivery pressure)


  • Consulting Engineers of Ontario Award of Merit, Pueblo Viejo 2013
  • The pressure-oxidation and air-separation-unit process areas were delivered on time and on budget despite that logistical challenges
  • Managed the transportation and logistics of the large pressure oxidation (autoclave) vessels and oxygen plant equipment, including a 120 km, 18-day, cross-country trek to the mine site
  • The air-separation unit was the largest-capacity oxygen facility built at any gold mine to date, by several orders of magnitude

Project Numbers

1.125 million ounces of gold per annum (first 5 years)
24,000 tpd utilizing 4 autoclave trains
230°C operating temperature
40 bar (g) operation pressure
500 kt S/yr design sulfur-oxidation capacity
Largest autoclaves in the world by weight (2,178 tonnes)
4,000 tpd oxygen plant-design construction management

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