Next generation autoclave vessel makes its way from Belgium to Russia

June 29, 2020

Amursk autoclave vessel being prepared for shipping 
Amursk autoclave vessel being prepared for shipping
Toronto, Canada—On May 18, Hatch released the world’s largest, custom-designed, high temperature autoclave from the Coek Engineering manufacturing facility in Geel, Belgium for Polymetal International's Phase 4 POX Hub Expansion Project located near Amursk, Khabarovsk, Eastern Russia. At 5.95 meters outside diameter, 50 meters in overall length, with an operating volume of 1,100 m3, and a shipping weight of 965 tonnes, this is the largest pressure oxidation (POX) autoclave in the world—that’s the weight equivalent of 150 full-grown African elephants and the length of 4 city buses. 


With an operating temperature of 240°C and operating pressure of 52 bar(g), the Amursk autoclave is the heart of a new POX circuit that will process double refractory (high carbon) sulphide gold concentrates from several Polymetal-owned mines located within the Russian Federation and Kazakhstan. The Amursk POX Hub Expansion will double Polymetal’s treatment capacity to 250,000-300,000 t/a of gold concentrate.

The vessel chemically oxidizes minerals such as pyrite and arsenopyrite, to liberate and recover sub-micron, solution-phase gold contained within the sulphide matrix. In six hours, it accomplishes what takes several hundreds of thousands of years to occur naturally in the earth. This aqueous (‘wet’) pressure oxidation process is also much more environmentally friendly than conventional processing options, which generate toxic by-products such as arsenic trioxide and sulphur dioxide that must be removed by expensive gas scrubbing systems.

“The Amursk autoclave vessel represents the next generation of pressure oxidation facilities,” said Joe Lombard, Global Managing Director, Metals at Hatch. “The design, procurement, fabrication, inspection, testing―and now transport—of this autoclave required an enormous effort from multiple teams around the globe. We are extremely proud to be part of this tremendous achievement.”
“The Amursk POX Hub autoclave vessel was custom-designed for extremely aggressive process conditions, including high temperature, high acidity, and elevated chlorides and fluorides,” explained Murray Pearson, Technology Development Director, High Pressure Metallurgy at Hatch. “The design pressure is 50% higher than any other POX autoclave currently in operation.”

Manufactured by Coek Engineering in Geel, Belgium, the material order and vessel fabrication and testing took 32 months to complete. Following final inspection, Hatch released the autoclave from Coek’s facility, where it was transferred by road and river barge to the Port of Antwerp, and loaded onto the MV Svenja, a heavy-lift ship, which sailed on May 25, 2020. The ship is expected to arrive in Port of De Castri, Russia in 30 days, where the vessel will be then transferred to a river barge for another 20-day journey to the project site.

For more information about the Amursk POX Hub Expansion Project, click here. For more information about our high-pressure metallurgy practice, click here.

For more information, please contact:

Lindsay Janca
Global Director, Public Relations
Tel: +1 905 403 4199

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