Petropavlovsk said reduced output of 95.6koz was primarily due to lower processing volumes and grades of third-party concentrates at the company's Pressure Oxidation (POX) Hub facility. The company uses the 500kt/yr POX plant in Pokrovskiy to process its own and third-party gold ore.

Production using the company's own ore fell 19% to 82.4koz in the first quarter, with marginally higher Malomir production offset by reduced output at the Albyn and Pioneer mines.

However, production of gold from third-party concentrate saw the biggest fall, to 13.2koz from 84.2koz, due to lower volumes of concentrate available for purchase and lower grades in the concentrates supplied.

The POX Hub can process previously untreatable refractory ores, where gold is locked in sulphides, said the company on its website.

The POX method begins with the same processes as a traditional Resin-in-pulp method where ore is mined, crushed and ground.  It then passes through a flotation circuit which produces a high-grade concentrate equating to between 2.8% and 4.2% of the original mass of the ore.  Concentrate is then transported to the POX Hub for further processing and gold recovery.

Petropavlovsk said it plans to commission a flotation plant at its Pioneer mine in the second quarter.

Once operational, the new Pioneer flotation plant will double the company's processing capacity from its own mines to 7.2Mtpa, "This will reduce the POX Hub's reliance on treating low-margin 3rd-party concentrates," said Petropavlovsk.

In the first quarter, Pioneer processed non-refractory ore from both open pit and underground mining operations to produce 24.1koz from ore with an average grade of 0.67g/t and recoveries of c.81%, in line with expectations.

The lower grade of ore processed relative to mined grades reflects the impact of stockpiling higher grade refractory gold ores ahead of the start-up of the new flotation plant

A third line is also under construction at the Malomir flotation plant is underway which will add 1.8Mtpa of flotation capacity from Q3 2022, bringing the total combined group capacity up to 9 Mtpa.

The company expects totalgold production this year of 430-470koz, comprising own gold production of 370-390koz and gold production from 3rd-party concentrate of 60 - 80koz.