NQ Minerals upgrades Hellyer processing plant, aims to maximise recoveries

NQ Minerals says it has successfully increased plant throughput at its flagship Hellyer gold mine, in Tasmania, Australia, following an upgrade and circuit optimisation exercise.

The plant now has a capacity just over 1.3 Mt/y (1.2 Mt/y at 92% plant availability), up from the 835,877 t throughput level achieved in 2019, NQ said.

“The new production rate of 150 t/h (1.314 Mt/y) is now being achieved after a June plant upgrade and circuit optimisation exercise,” the company said. “This new rate compares to 2019 Hellyer full year plant throughput totalling 835,877 t (average 103 t/h at 92% plant availability).”

A spokesperson for the company said the exercise in June saw a lot of work carried out on upsizing existing pumps and pipework to handle the extra flow rates of the various process streams. This saw the installation of bigger pumps and pipes, and the replacement of worn components in the plant.

“Process optimisation works are now underway to ensure that the plant achieves maximum recoveries and concentrate specifications at these new higher production rates,” NQ Minerals said. This could see new automation equipment installed on some of the process circuit, according to the spokesperson.

“Engineering assessments will continue to plan for further production rate increases later in the year, should higher production rates be required,” the company added.

David Lenigas, Chairman of NQ Minerals, said the Hellyer plant upgrade exercise had been successfully brought in some six months ahead of expectation.

“The increase in saleable mine product will have a very positive effect on the company’s top and bottom line revenues going forward, and will assist NQ greatly with its ability to service ongoing debt obligations and strongly position the mine for increased profitability as commodity prices improve with the world emerging from the COVID-19 pandemic,” he said.

NQ Minerals purchased the Hellyer operations in 2017, and as Phase 1 of its Hellyer operational plan, re-opened Hellyer in late 2018 with a tailing retreatment operation designed to last for at least 10 years. Production will initially focus on lead and zinc recovery from the reserves with gold and silver credits.

Phase 2 of Hellyer’s re-opening plan is to re-open the underground mine, which has 1.175 Mt of underground JORC resources grading 8.6% Zn, 4.9% Pb, 96 g/t Ag and 1.66 g/t Au.