Plutonic is the highest-cost of Northern Star's five mines, producing around 79,000 ounces last financial year at an all-in sustaining cost of $1550 an ounce.
Gold miners in particular have stepped up technology investment within a falling capex budget, as the metal price in producers’ currencies has held up much better than other commodities.
It expects to sell the key crop nutrient for $200-230 a tonne in the current quarter, compared to an average price of $254 a tonne in the previous three-month period.